WorldWideScience

Sample records for kaolinitic thermic typic

  1. Infrared and infrared emission spectroscopic study of typical Chinese kaolinite and halloysite.

    Science.gov (United States)

    Cheng, Hongfei; Frost, Ray L; Yang, Jing; Liu, Qinfu; He, Junkai

    2010-12-01

    The structure and thermal stability between typical Chinese kaolinite and halloysite were analysed by X-ray diffraction (XRD), infrared spectroscopy, infrared emission spectroscopy (IES) and Raman spectroscopy. Infrared emission spectroscopy over the temperature range of 300-700°C has been used to characterise the thermal decomposition of both kaolinite and halloysite. Halloysite is characterised by two bands in the water bending region at 1629 and 1648 cm(-1), attributed to structural water and coordinated water in the interlayer. Well defined hydroxyl stretching bands at around 3695, 3679, 3652 and 3625 cm(-1) are observed for both kaolinite and halloysite. The 550°C infrared emission spectrum of halloysite is similar to that of kaolinite in 650-1350 cm(-1) spectral region. The infrared emission spectra of halloysite were found to be considerably different to that of kaolinite at lower temperatures. These differences are attributed to the fundamental difference in the structure of the two minerals. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. thermic oil and molten salt

    African Journals Online (AJOL)

    Boukelia T.E, Mecibah M.S and Laouafi A

    1 mai 2016 ... [27] Zavoico, AB. Solar Power Tower Design Basis Document. Tech. rep, Sandia National. Laboratories, SAND2001-2100, 2001. How to cite this article: Boukelia T.E, Mecibah M.S and Laouafi A. Performance simulation of parabolic trough solar collector using two fluids (thermic oil and molten salt).

  3. Thermic diode performance characteristics and design manual

    Science.gov (United States)

    Bernard, D. E.; Buckley, S.

    1979-01-01

    Thermic diode solar panels are a passive method of space and hot water heating using the thermosyphon principle. Simplified methods of sizing and performing economic analyses of solar heating systems had until now been limited to passive systems. A mathematical model of the thermic diode including its high level of stratification has been constructed allowing its performance characteristics to be studied. Further analysis resulted in a thermic diode design manual based on the f-chart method.

  4. Co adsorption in kaolinite

    International Nuclear Information System (INIS)

    Souza, Eliel S.; Silva, Paulo S.C.

    2017-01-01

    Adsorption of metal ions in clay minerals has been used as an alternative to water and effluents treatment. Kaolinite is a clay mineral that presents low specific surface area and exchange ion capacity. Nevertheless, structural modifications can be achieved by means of acid or thermal activation. In this paper, it was studied the surface area of kaolinite/bentonite, kaolinite/activated carbon mixtures, thermal activated kaolinite and thermal activated kaolinite/activated carbon mixture. The mixture of kaolinite/activated carbon was tested for pH, contact time, interfering ions and initial concentration effects in the cobalt adsorption. Results showed that the optimized parameters are pH 6 and contact time of 30 min. Chromium acted as a competitive ion, zinc does not appear to have affected adsorption while iron seems to have favored it. Langmuir and Freundlich isotherms indicated that the adsorption of Co in the mixture of kaolinite/activated carbon is a spontaneous process. (author)

  5. Co adsorption in kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Eliel S.; Silva, Paulo S.C., E-mail: eliel201019@hotmail.com, E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energética s e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Adsorption of metal ions in clay minerals has been used as an alternative to water and effluents treatment. Kaolinite is a clay mineral that presents low specific surface area and exchange ion capacity. Nevertheless, structural modifications can be achieved by means of acid or thermal activation. In this paper, it was studied the surface area of kaolinite/bentonite, kaolinite/activated carbon mixtures, thermal activated kaolinite and thermal activated kaolinite/activated carbon mixture. The mixture of kaolinite/activated carbon was tested for pH, contact time, interfering ions and initial concentration effects in the cobalt adsorption. Results showed that the optimized parameters are pH 6 and contact time of 30 min. Chromium acted as a competitive ion, zinc does not appear to have affected adsorption while iron seems to have favored it. Langmuir and Freundlich isotherms indicated that the adsorption of Co in the mixture of kaolinite/activated carbon is a spontaneous process. (author)

  6. Interactions between whey proteins and kaolinite surfaces

    International Nuclear Information System (INIS)

    Barral, S.; Villa-Garcia, M.A.; Rendueles, M.; Diaz, M.

    2008-01-01

    The nature of the interactions between whey proteins and kaolinite surfaces was investigated by adsorption-desorption experiments at room temperature, performed at the isoelectric point (IEP) of the proteins and at pH 7. It was found that kaolinite is a strong adsorbent for proteins, reaching the maximum adsorption capacity at the IEP of each protein. At pH 7.0, the retention capacity decreased considerably. The adsorption isotherms showed typical Langmuir characteristics. X-ray diffraction data for the protein-kaolinite complexes showed that protein molecules were not intercalated in the mineral structure, but immobilized at the external surfaces and the edges of the kaolinite. Fourier transform IR results indicate the absence of hydrogen bonding between kaolinite surfaces and the polypeptide chain. The adsorption patterns appear to be related to electrostatic interactions, although steric effects should be also considered

  7. Interactions between whey proteins and kaolinite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Barral, S. [Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Villa-Garcia, M.A. [Department of Organic and Inorganic Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain)], E-mail: mavg@uniovi.es; Rendueles, M. [Project Management Area, University of Oviedo, Independencia 13, 33004 Oviedo (Spain); Diaz, M. [Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain)

    2008-07-15

    The nature of the interactions between whey proteins and kaolinite surfaces was investigated by adsorption-desorption experiments at room temperature, performed at the isoelectric point (IEP) of the proteins and at pH 7. It was found that kaolinite is a strong adsorbent for proteins, reaching the maximum adsorption capacity at the IEP of each protein. At pH 7.0, the retention capacity decreased considerably. The adsorption isotherms showed typical Langmuir characteristics. X-ray diffraction data for the protein-kaolinite complexes showed that protein molecules were not intercalated in the mineral structure, but immobilized at the external surfaces and the edges of the kaolinite. Fourier transform IR results indicate the absence of hydrogen bonding between kaolinite surfaces and the polypeptide chain. The adsorption patterns appear to be related to electrostatic interactions, although steric effects should be also considered.

  8. Kaolinite Mobilisation in Sandstone

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke; Kets, Frans

    2013-01-01

    suggest that this effect is due to kaolinite clay mobilisation from the quartz grain surface; the mobilised particles subsequently plug the pore throats and reduce the permeability irreversibly. The expected hysteresis is observed when the salinity is reduced and increased; however, in contradiction...... the mobilised kaolinite particles either remain suspended and thereby increase the fluid viscosity, or form porous aggregates that can be destabilized by hydrodynamic forces. To address how the pore scale distribution of kaolinite relates to the permeability of the entire sample, we relate permeability...

  9. 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.

  10. Metal sorption on kaolinite

    International Nuclear Information System (INIS)

    Westrich, H.R.; Brady, P.V.; Cygan, R.T.; Nagy, K.L.; Anderson, H.L.

    1997-01-01

    A key issue in performance assessment of low-level radioactive waste sites is predicting the transport and retardation of radionuclides through local soils under a variety of hydrologic and geochemical conditions. Improved transport codes should include a mechanistic model of radionuclide retardation. The authors have been investigating metal sorption (Cs + , Sr 2+ , and Ba 2+ ) on a simple clay mineral (kaolinite) to better understand the geochemical interactions of common soil minerals with contaminated groundwaters. These studies include detailed characterizations of kaolinite surfaces, experimental adsorption measurements, surface complexation modeling, and theoretical simulations of cation sorption. The aluminol edge (010) site has been identified as the most likely site for metal sorption on kaolinite in natural solutions. Relative metal binding strengths decrease from Ba 2+ to Sr 2+ to Cs + , with some portion sorbed on both kaolinite edges and basal surfaces. Some Cs + also appears to be irreversibly sorbed on both sites. Molecular dynamics simulations suggest that Cs + is sorbed at aluminol (010) edge sites as an inner-sphere complex and weakly sorbed as an outer-sphere complex on (001) basal surfaces. These results provide the basis to understand and predict metal sorption onto kaolinite, and a framework to characterize sorption processes on more complex clay minerals

  11. Bibliometric analysis on kaolinite flotation

    Directory of Open Access Journals (Sweden)

    Gabriela Lieberknecht

    Full Text Available Abstract The current work presents a bibliometric discussion on articles published worldwide concerning kaolinite flotation in international journals from 1992 to 2015. In total, 39 articles were selected from Elsevier's database, SciVerse ScienceDirect. This work allowed to recognize and identify which are the thematic and methodological trends that are being used, in addition to the main collectors used in kaolinite flotation. The results show that a significant amount of articles is produced by Chinese authors, especially from 2013, as China is the second highest aluminum producer in the world, and kaolinite is the reject in the reverse flotation process of diaspore. The results showed the difficulty of working with kaolinite flotation individually and confirmed that there is scientific collaboration among authors. Bibliometric analysis showed that the reagents used in kaolinite flotation tests are mostly derived from cationic nitrogenated compounds. Additionally, best recovery results from kaolinite flotation occurred in acidic media.

  12. Thermic insulation in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaon, G. (Ambassade de France a New York (USA)); Atlas, O. (Illinois Institute of Technology, Chicago, (USA))

    1984-01-30

    At present, thermic insulation accounts for 13% of the savings which have been made and this percentage should increase substantially in the future. The ideal insulation material must have low thermic conductivity, but also be light, have a low dilatation coefficient, good mechanical resistance and be fireproof and non-toxic. Rock wool and above all glass wool have the major portion in the insulation market with about 75% of the total. The prospects for an increase in sales are average: 6 to 7% per year until 1990 with a stabilization or a decrease after this date. Production is concentrated in the hands of about ten producers. The insulation with a cellulose base -with the addition of a combustion inhibitor, usually borax- represent about 15% of the market. Manufacturers are numerous and the production units are small. Any serious evaluation of the future of this product is difficult to make. However, it should be noted that combustion inhibition is one of the main factors of success of this product and constitutes a relatively active field of research. Perlite and vermiculite have a marginal part of the market which is concentrated in the hands of a few dozen producers. Their future seems promising and their production should double between now and the end of the century. There is also the field of plastics which has to be considered and notably polystyrene, polyurethanes and polyisocyanates. These can be injected and moulded in situ. To the extent that toxicity studies can definitively conclude that they are not harmful (urea-formol resins have just been prohibited), their future is brillant and their growth rate could reach about 200% per year. The big chemical and pharmaceutical companies are interested in these products and their portion of the market can rapidly go beyond their present 6 to 8%.

  13. Bibliometric analysis on kaolinite flotation

    OpenAIRE

    Lieberknecht, Gabriela; Matai, Patrícia Helena Lara dos Santos; Leal Filho, Laurindo de Salles

    2017-01-01

    Abstract The current work presents a bibliometric discussion on articles published worldwide concerning kaolinite flotation in international journals from 1992 to 2015. In total, 39 articles were selected from Elsevier's database, SciVerse ScienceDirect. This work allowed to recognize and identify which are the thematic and methodological trends that are being used, in addition to the main collectors used in kaolinite flotation. The results show that a significant amount of articles is produc...

  14. Characterisation of kaolinite and adsorption of europium on kaolinite

    International Nuclear Information System (INIS)

    Olin, M.; Puhakka, E.; Lehikoinen, J.; Puukko, E.; Hakanen, M.; Lindberg, A.

    2007-10-01

    Kaolinite is a common fracture mineral in many crystalline rocks and, thus, a potential sorbent for groundwater solutes. The low cation-exchange capacity makes kaolinite a good mineral to study sorption by inner-sphere complexation of multivalent ions, such as trivalent actinides or their analogues, the trivalent lanthanides. The sorption of europium and americium on kaolinite has been studied previously by Puukko and Hakanen using a natural kaolinite, KGa-1b (from the Clay Minerals Society, USA). This work describes the determination of surface-charging mechanism and surface acidity constants for KGa-1b kaolinite, and adsorption of Eu(III) on both the natural (KGa-1b) and its acid-conditioned form (HKGa). The ionic strength of the background NaNO 3 electrolyte used in these titrations was 0.05 M, 0.1 M and 0.5 M. The surface acidity of kaolinite was explained using the FITEQL software by applying the 1-pK model. The optimized concentration of surface sites was close to a value previously reported for KGa-1b kaolinite. The adsorption modelling of europium was carried out by adopting one surfacecomplexation and one cation-exchange reaction. In the acidic pH range, sorption of europium decreased with increasing ionic strength of the NaNO 3 solution, which is an indication of the dominance of cation exchange or outer-sphere complexation. At the lowest ionic strength, the sorption was reversible. In the 0.1 M and 0.5 M NaNO 3 solutions, the sorption of europium in the basic pH range was only partly reversible, or desorption kinetically slow. The degree of irreversibility increased with increasing pH and ionic strength. A diffuse-layer model was readily fitted on the per-cents sorbed scale (default in FITEQL), but the results were not as good on a Kd scale, especially at circumneutral pH values. In the water analysis of the batch titration of KGa-1b kaolinite, the main observed elements were aluminium and zinc. The concentrations of Al and Zn decreased with p

  15. Uranium (VI) transport in saturated heterogeneous media: Influence of kaolinite and humic acid.

    Science.gov (United States)

    Chen, Chong; Zhao, Kang; Shang, Jianying; Liu, Chongxuan; Wang, Jin; Yan, Zhifeng; Liu, Kesi; Wu, Wenliang

    2018-05-07

    Natural aquifers typically exhibit a variety of structural heterogeneities. However, the effect of mineral colloids and natural organic matter on the transport behavior of uranium (U) in saturated heterogeneous media are not totally understood. In this study, heterogeneous column experiments were conducted, and the constructed columns contained a fast-flow domain (FFD) and a slow-flow domain (SFD). The effect of kaolinite, humic acid (HA), and kaolinite/HA mixture on U(VI) retention and release in saturated heterogeneous media was examined. Media heterogeneity significantly influenced U fate and transport behavior in saturated subsurface environment. The presence of kaolinite, HA, and kaolinite/HA enhanced the mobility of U in heterogeneous media, and the mobility of U was the highest in the presence of kaolinite/HA and the lowest in the presence of kaolinite. In the presence of kaolinite, there was no difference in the amount of U released from the FFD and SFD. However, in the presence of HA and kaolinite/HA, a higher amount of U was released from the FFD. The findings in this study showed that medium structure and mineral colloids, as well as natural organic matter in the aqueous phase had significant effects on U transport and fate in subsurface environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. A bio-thermic seawater desalination system using halophytes

    NARCIS (Netherlands)

    Finck, C.

    2014-01-01

    A bio-thermic seawater desalination system using halophytes was developed and successfully tested. A greenhouse as part of a test rig, with different sorts of mangroves, was installed. Measurements showed promising results concerning fresh water relative yielding rates up to 1.4 kg/h/m2 (leaf

  17. Thermically stimulated exoelectronic emissions and thermoluminescence of MgO

    International Nuclear Information System (INIS)

    Chubaci, J.F.D.

    1987-01-01

    In this work, studies were performed on the following topics: i) thermically stimulated exoelectronic emission (TSEE) in pure MgO single crystals ion implanted, submitted to thermal treatment with fast on slow cooling and water adsorption; ii) ultraviolet light effect on TSEE; iii) thermoluminescent emission; iv) crystallization of FeCoB amorphous alloys. (A.C.A.S.) [pt

  18. Report on thermic effects in the study of the control and propagation of nuclear reactions

    International Nuclear Information System (INIS)

    Naudet, R.

    It is very likely that nuclear reactions in natural reactors are governed by temperature, chiefly as a result of the moderation rate when the water density is altered. Since reactors operate under high pressure, with supercritical water, high temperatures (at least 350 to 400 0 C in some instances) are required in order to stabilize the reactors. Some typical calculations are shown in order to illustrate the changes in the control temperature during irradiation. The speed and, therefore, the duration of reactions is determined by the need to maintain the necessary temperature required for criticality, with heat dissipation conditions taken into account. Apparent measured durations are compatible with heat dissipation by simple conduction. However, it is likely that convection currents exist, and that their effects are superimposed on those of simple conduction. Reaction propagation must also be taken into consideration since criticality cannot be realized simultaneously at every point. The presence of impurities such as gadolinium or samarium in the mineral ore allows reactions to propagate in initially subcritical increments, through progressive breakdown of the impurities by means of neutronic diffusion. However, it has been shown that this phenomenon is seriously affected by thermic effects. Typical calculations are presented. Results clearly depend on temperature distribution hypotheses; sufficient thermic coupling can totally inhibit reaction propagation. It is concluded that, if convection currents are present, propagation is favored inversely with respect to the currents, and therefore a priori downstream of the reactors. 6 figures

  19. Characterization of exfoliated/delamination kaolinite

    International Nuclear Information System (INIS)

    Sun, Dewen; Li, Bin; Li, Yanfeng; Yu, Cui; Zhang, Bo; Fei, Huafeng

    2011-01-01

    A novel and facile approach for the preparation of exfoliated/delamination kaolinite was reported in this study. Kaolinite was mechanochemically activated by grinding with dimethylsulfoxide in a globe mill for different periods of time, and then the activated samples were treated for several hours at 120 o C to obtain the precursors of kaolinite. The resulting materials were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The experimental data indicated that the clay layers were well exfoliated/delamination under mechanochemical effect in a significantly short intercalation time. The expansion of the basal spacing (d 001 ) of raw kaolinite by 0.40 nm pointed out that the hydrogen bonds between adjacent kaolinite layers were partially broken as a result of the intercalation with dimethylsulfoxide.

  20. The Influence of Thermic Plastic Films on Vegetative and Reproductive Growth of Iceberg Lettuce 'Dublin'

    OpenAIRE

    Wael M. Semida; P. Hadley; W. Sobeih; N. A. El-Sawah; M. A. S. Barakat

    2013-01-01

    Photoselective plastic films with thermic properties are now available so that greenhouses clad with such plastics exhibit a higher degree of “Greenhouse Effect” with a consequent increase in night time temperature. In this study, we investigate the potential benefits of a range of thermic plastic films used as greenhouse cover materials on the vegetative and reproductive growth and development of Iceberg lettuce (Lactuca sativa L). Transplants were grown under thermic fi...

  1. POLYPROPYLENE-MODIFIED KAOLINITE COMPOSITES: EFFECT ...

    African Journals Online (AJOL)

    Meziane O, Bensedira A, Guessoum M and Haddaoui N

    2016-05-01

    May 1, 2016 ... prepared by the melt intercalation method. ... several beneficial variations on stiffness, hardness, toughness and heat ..... Polypropylene/ untreated and treated kaolinite composites have been prepared via direct melt.

  2. Sorption of Eu(III) to Kaolinite in the Presence of Humic Acids

    International Nuclear Information System (INIS)

    Shin, Hyun Sang; Harn, Yoon I; Oh, Se Jin

    2010-05-01

    The sorption of europium(Eu(III)) onto kaolinite and the influence of humic acids over a range of pH 3 ∼ 11 has been studied by batch adsorption experiment (V/m = 250:1 mL/g, CEu(III) = 1x10 -5 mol/L, C HA = 5 ∼ 50 mg/L, PCO 2 = 10 -3.5 atm). The concentrations of HA and Eu(III) in aqueous phase were measured by UV absorbance at 254 nm(e.g., UV 254 ) and ICP-MS after microwave digestion for HA removals, respectively. Results showed that the HA sorption onto kaolinite was decreased with increasing pH and their sorption isotherms fit well with the Langmuir adsorption model (except pH 3). Maximum amount(q max ) for the HA sorption at pH 4 to 11 was ranged from 4.73 to 0.47 mg/g. Europium adsorption onto the kaolinite in the absence of HA was typical, showing an increases with pH and a distinct adsorption edge at pH 3 to 5. However in the presence of HA, Eu adsorption to kaolinite was significantly affected. HA was shown to enhance Eu adsorption in the acidic pH range (pH 3 ∼ 4) due to the formation of additional binding sites for Eu coming from HA adsorbed onto kaolinite surface, but reduce Eu adsorption in the intermediate and high pH above 6 due to the formation of aqueous Eu-HA complexes. The results on the ternary interaction of kaolinite-Eu-HA are compared with those on the binary system of kaolinite-HA and kaolinite-Eu and adsorption mechanism with pH was discussed

  3. Experimental study for development of thermic lance cutting method

    International Nuclear Information System (INIS)

    Machida, N.; Katano, Y.; Kamiya, Y.

    1988-01-01

    A series of experiments on a thermic lance cutting method were carried out to obtain useful data for the practical application of this method to the dismantling of reinforced concrete. As a first step, a performance experiment was executed to study basic cutting performance relating to oxygen consumption, extent of bar loss and cutting speed, as well as by-products generated during cutting work such as powdered dust, gas, fumes and slag. An automated and remote-controlled cutting machine was then developed utilizing automated bar supply and ignition. This paper describes the result of these experiments. (author)

  4. Thermic responses to vegetarian meals and yoga exercise.

    Science.gov (United States)

    Agte, V; Chiplonkar, S

    1992-01-01

    The thermic effect (TEF) of vegetarian meals was measured for breakfast and lunch in 6 lean healthy men (18-25 years) during normal feeding (NF) and with 20% overfeeding (OF) on 28 successive days. The energy contents of breakfast were 223 +/- 10 and 330 +/- 48 kcal, and those of lunch were 1,033 +/- 220 and 1,247 +/- 222 kcal in NF and OF, respectively. In NF, the TEF per 180 min was 32.7 +/- 8.6 and 54.8 +/- 6.3 kcal for breakfast and lunch, respectively. In OF, the TEF was 38.3 +/- 8.3 kcal for breakfast and 57.2 +/- 5.4 kcal for lunch. The increase in total TEF due to OF was nonsignificant (p greater than 0.2). In response to 20% OF, adaptive thermogenesis was manifested mainly through an increase in the resting metabolic rate of 4.9% (p less than 0.001). In both feeding, regimes, the percent TEF was higher for breakfast than for lunch (p less than 0.05). Regression analysis of TEF versus calorie load indicated a stable component of 42 kcal with a 2% rate of increase. Yoga exercises were performed from 16.00 to 17.00 daily. The thermic effect of yoga exercises observed from 17.10 to 18.30 was 21 kcal and persisted beyond 90 min, indicating the role of yoga in energy metabolism.

  5. Structural Modification of Egyptian Kaolinite for Paper Coating

    International Nuclear Information System (INIS)

    Mohamed, H.F.; Hassan, M.S.; Morsy, F.A.; El-Sherbiny, S.

    2013-01-01

    The aim of this work is surface modification of Egyptian kaolinite for paper coating. Kaolinite < 2 fraction (KF) obtained using sedimentation and centrifuging techniques. Organo-kaolinite was prepared via inserting Urea (NH 2 CO NH 2 ) within the gallery of kaolinite using grinding technique for different times. Nano kaolinite was prepared from dispersion of organo-kaolinite in paper coating. The kaolinite (K), kaolinite /urea (KU) and kaolinite urea with binder (KU/Binder) were characterized using X-ray diffractometry (XRD), Infrared spectroscopy (IR) and Scanning Electron Microscopy (SEM). XRD studies revealed shifting of basal space of kaolinite from 0.714 to 1.11 nm upon grinding of kaolinite with urea for 5 h. On the other hand, the characteristic peak of kaolinite completely disappeared during dispersion of KU in paper coating suspension, which revealed the exfoliation of organo-kaolinite layers through the binder. Meanwhile, IR spectra show that NH-CO molecule exists in the intercalated kaolinite. The SEM images of KU revealed that kaolinite is intercalated U and fully exfoliation of KU achieved in KU/Binder and revealed by thin flakes with particle size ranged from 500 nm and 300 nm respectively. The modified kaolinite for paper coating increased the optical properties in terms of ISO brightness, opacity and gloss of the coated paper. There was a significant decrease in coated paper roughness compared to untreated kaolinite. Air permeance of the KF decreased in comparison with K sample, but increased sharply by intercalation of kaolinite (KU). Burst strength also started to increase with untreated kaolinite but decreased sharply with urea KU.

  6. Santa Cruz thermic plant islanding with local loads

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, A R [Light Servicos de Eletricidade SA, Rio de Janeiro, RJ (Brazil); Gomes, Paulo; Almeida, Paulo C. de [ELETROBRAS, Rio de Janeiro, RJ (Brazil); Sereno, Marcos G [FURNAS, Rio de Janeiro, RJ (Brazil)

    1988-12-31

    This work looks into the feasibility of implementing a scheme for the islanding of the Santa Cruz Thermic Plant ( Rio de janeiro State) with LIGHT`s (Electric power public utility) loads fed by the Santa Cruz-Jacarepagua trunk connection, considering presently-existing system problems relative to a significant frequency drop when a loss occurs of a large generation block and which causes the blockade scheme of the mentioned Plant to work, thus aggravating the frequency control still further. An analysis is made of such scheme implementation implications on the scheme for islanding a Santa Cruz 84 MW machine to provide supply to the auxiliary services of The Angra dos Reis nuclear plant presently existing in the system. 2 refs., 9 figs.

  7. A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study.

    Science.gov (United States)

    Cheng, Hongfei; Yang, Jing; Liu, Qinfu; Zhang, Jinshan; Frost, Ray L

    2010-11-01

    Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm⁻¹ between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite - A mid-infrared and near-infrared study

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H.F.; Yang, J.; Liu, Q.F.; Zhang, J.S.; Frost, R.L. [Queensland University of Technology, Brisbane, Qld. (Australia). Faculty of Science & Technology

    2010-11-15

    Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm{sup -1} between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis.

  9. Kaolinite removal from bauxite by flotation

    Directory of Open Access Journals (Sweden)

    Otávia Martins Silva Rodrigues

    Full Text Available Abstract This paper presents a potential condition to separate kaolinite through flotation when it is present in bauxite ore. This research anticipates a Brazilian industry requirement, considering the tendency towards the need for aluminosilicates removal from bauxite ores, as has already occurred in China. Kaolinite is the most abundant aluminosilicate, and gibbsite is the main aluminum bearing mineral in Brazilian bauxite ores. The first step was a fundamental study involving microflotation experiments with pure samples of kaolinite and gibbsite. Ammonium quaternary salts and amines were used as the collector and corn starch as the depressant. In a fundamental study, the best conditions determined in the first step were evaluated for the flotation of kaolinite from bauxite ore using laboratory scale experiments. Tests with AQ142/starch (pH 10 and CTAB (pH 7 led to satisfactory results. In general, the highest values of alumina/silica mass ratio were obtained with AQ142/starch and the highest values of mass recovery and metallurgical recovery were achieved with CTAB.

  10. Neptunium(V) sorption on kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Amayri, S.; Jermolajev, A.; Reich, T. [Mainz Univ. (Germany). Inst. of Nuclear Chemistry

    2011-07-01

    The sorption behavior of neptunium(V) onto the clay mineral kaolinite was studied in batch experiments under different experimental conditions: [Np(V)] = 7 x 10{sup -12}-8 x 10{sup -6} M, solid-to-liquid ratio 2-20 g L{sup -1}, I = 0.1 and 0.01 M NaClO{sub 4}, pH = 6-10, ambient air and Ar atmosphere. The short-lived isotope {sup 239}Np (T{sub 1/2} = 2.36 d) was used instead of {sup 237}Np (T{sub 1/2} = 2.14 x 10{sup 6} a) to study the sorption behavior of Np(V) at environmentally-relevant concentrations, i.e., 7 x 10{sup -12} M Np. In addition, {sup 239}Np(V) served as tracer to measure sorption isotherms over six orders of magnitude in Np concentration (4.8 x 10{sup -12}-1.0 x 10{sup -4} M). The results show that Np(V) sorption on kaolinite is strongly influenced by pH, CO{sub 2}, and ionic strength. The sorption of 8 x 10{sup -6} M Np(V) at pH 9.0, and ionic strength of 0.1 M NaClO{sub 4} was proportional to the solid-to-liquid ratio of kaolinite in the range of 2-10 g L{sup -1}. In the absence of CO{sub 2}, the Np(V) uptake increased continuously with increasing pH value up to 97% at pH 10. Under ambient CO{sub 2}, the sorption of Np decreased above pH 8 up to zero at pH 10. An increase of Np(V) concentration from 7 x 10{sup -12} to 8 x 10{sup -6} M resulted in a shift of the sorption pH edge by up to one pH unit to higher pH values. The ionic strength influenced the Np(V) sorption onto kaolinite only in the presence of ambient CO{sub 2}. Under Ar atmosphere the sorption of Np(V) was independent from ionic strength, indicating the formation of inner-sphere complexes of Np(V) with kaolinite. Time-dependent batch experiments at pH 9.0 under ambient CO{sub 2} showed that the sorption of Np(V) on kaolinite is fast and fully reversible over six orders in Np(V) concentration. (orig.)

  11. EXAFS study of plutonium sorption onto kaolinite

    International Nuclear Information System (INIS)

    Reich, T.Y.; Banik, L.; Buda, R.A.; Amayri, S.; Drebert, J.; Kratz, J.V.; Trautmann, N.; Reich, T.; Ageev, A.L.; Korshunov, M.E.

    2007-01-01

    The uptake mechanism of plutonium by kaolinite was investigated by applying X-ray absorption spectroscopy to batch sorption samples (total Pu concentrations 1 and 10 μM; 4 g kaolinite/L in 0.1 M NaClO 4 ; 1 ≤ pH ≤ 9; presence and absence of ambient CO 2 ). For XAFS measurements, one sample was prepared from a Pu(III) solution at pH 6 under argon atmosphere. Three samples were obtained by sorption of Pu(IV) at pH I, 4, and 9 in an air-equilibrated system. The Pu L III -edge XANES spectra indicated that in all samples, including the Pu(III) sample, plutonium is sorbed at the kaolinite surface as Pu(IV). The Pu L III -edge k 3 -weighted EXAFS spectra showed eight oxygen atoms at an average Pu-O distance of 2.3 angstrom. Two Pu atoms were detected at ∼ 3.7 angstrom in all spectra, indicating the formation of polynuclear Pu(IV) species at the kaolinite surface. For the sample prepared from Pu(III) solution, an additional Pu-O shell at 3.2 angstrom was observed. The spectra of samples prepared from Pu(IV) included a Pu-Al/Si co-ordination shell at approximately 3.6 angstrom, indicating formation of inner-sphere sorption complexes. The structural models used in the least-squares fits were confirmed by an alternative EXAFS data analysis approach based on a modified Tikhonov regularization method. (authors)

  12. Molecular Treatment of Nano-Kaolinite Generations.

    Science.gov (United States)

    Táborosi, Attila; Szilagyi, Robert K; Zsirka, Balázs; Fónagy, Orsolya; Horváth, Erzsébet; Kristóf, János

    2018-06-18

    A procedure is developed for defining a compositionally and structurally realistic, atomic-scale description of exfoliated clay nanoparticles from the kaolinite family of phylloaluminosilicates. By use of coordination chemical principles, chemical environments within a nanoparticle can be separated into inner, outer, and peripheral spheres. The edges of the molecular models of nanoparticles were protonated in a validated manner to achieve charge neutrality. Structural optimizations using semiempirical methods (NDDO Hamiltonians and DFTB formalism) and ab initio density functionals with a saturated basis set revealed previously overlooked molecular origins of morphological changes as a result of exfoliation. While the use of semiempirical methods is desirable for the treatment of nanoparticles composed of tens of thousands of atoms, the structural accuracy is rather modest in comparison to DFT methods. We report a comparative survey of our infrared data for untreated crystalline and various exfoliated states of kaolinite and halloysite. Given the limited availability of experimental techniques for providing direct structural information about nano-kaolinite, the vibrational spectra can be considered as an essential tool for validating structural models. The comparison of experimental and calculated stretching and bending frequencies further justified the use of the preferred level of theory. Overall, an optimal molecular model of the defect-free, ideal nano-kaolinite can be composed with respect to stationary structure and curvature of the potential energy surface using the PW91/SVP level of theory with empirical dispersion correction (PW91+D) and polarizable continuum solvation model (PCM) without the need for a scaled quantum chemical force field. This validated theoretical approach is essential in order to follow the formation of exfoliated clays and their surface reactivity that is experimentally unattainable.

  13. Characterization of the natural kaolinite KGa-1b

    International Nuclear Information System (INIS)

    Puukko, E.; Hakanen, M.

    2003-05-01

    Kaolinite is a common mineral on the surfaces of fractures in the rock. The sorption of europium and americium on kaolinite has been studied in a previous study (Puukko and Hakanen, 2001) using a natural kaolinite, KGa-1b (from the Clay Mineral Society, USA). Before experiments the kaolinite was washed with acid (HCl). The washing with acid removed iron but not TiO 2 . Surface complexation model has been applied to model the acid base reactions of kaolinite and the sorption of americium and europium on the kaolinite. In the present work the sorption of europium on the natural kaolinite KGa-1b was studied. The characterization of the natural kaolinite KGa- 1b is needed in the modelling of the sorption experiments. The iron impurities in the kaolinite were extracted with phase selective solutions to determine if the iron was amorphous and crystalline. The dissociation constants of kaolinite KGa-1b were determined by acid base titration in 0.05 M, 0.1 M and 0.5 M NaNO 3 solutions by two methods: a continuous titration and a batch titration. The solutions of the batch titrations were analysed for dissolved cations and silica and lanthanides at the laboratory of the Geological Survey of Finland (GSF). The loss in ignition of the KGa-1b was 14.3 w-% according to the Clay Mineral Society. The possible presence of humic acids was investigated at the GSF using thermogravimetry, X-ray diffraction and IR spectrometry and in the Laboratory of Physical Chemistry by measuring IR-absorption of gases released from a heated sample. The kaolinite KGa-1b contains a small quantity of iron. The phase selective extraction of amorphous iron gave almost same results as crystalline iron. The quantities of pure iron oxide phases of the total iron content was very low. The thermogravimetry and XRD analysis of the kaolinite KGa-1b indicated no presence of organic impurities, especially humic acids. The sensitivity of the IR analysis was not high enough to detect humic acids in the kaolinite

  14. Kaolinitic clay-based grouting demonstration

    International Nuclear Information System (INIS)

    McCloskey, A.L.; Barry, C.J.; Wilmoth, R.

    1997-01-01

    An innovative Kaolinitic Clay-Based Grouting Demonstration was performed under the Mine Waste Technology Program (MWTP), funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by the EPA and the U.S. Department of Energy (DOE). The objective of the technology was to demonstrate the effectiveness of kaolinitic clay-based grouting in reducing/eliminating infiltration of surface and shallow groundwater through fractured bedrock into underground mine workings. In 1993, the Mike Horse Mine was selected as a demonstration site for the field implementation and evaluation of the grouting technology. The mine portal discharge ranged between 114 to 454 liters per minute (30 to 120 gpm) of water containing iron, zinc, manganese, and cadmium at levels exceeding the National Drinking Water Maximum Contaminant Levels. The grout formulation was designed by the developer Morrison Knudsen Corporation/Spetstamponazhgeologia (MK/STG), in May 1994. Grout injection was performed by Hayward Baker, Inc. under the directive of MSE Technology Applications, Inc. (MSE-TA) during fall of 1994. The grout was injected into directionally-drilled grout holes to form a grout curtain at the project site. Post grout observations suggest the grout was successful in reducing the infiltration of the surface and shallow groundwater from entering the underground mine workings. The proceeding paper describes the demonstration and technology used to form the subsurface barrier in the fracture system

  15. Strontium adsorption and penetration in kaolinite at low Sr

    NARCIS (Netherlands)

    Ning, Zigong; Ishiguro, Munehide; Koopal, Luuk K.; Sato, Tsutomu; Kashiwagi, Junichi

    2017-01-01

    Behavior of radioactive strontium (Sr2+) in contaminated soils is an important issue in relation to nuclear power plant accidents. The Sr2+ adsorption on kaolinite and its migration in a kaolinite soil were investigated because toxic effects of radioactive Sr2+ have been found to be very severe for

  16. Theoretical study for the interlamellar aminoalcohol functionalization of kaolinite

    International Nuclear Information System (INIS)

    Hou, Xin-Juan; Li, Huiquan; Liu, Qinfu; Cheng, Hongfei; He, Peng; Li, Shaopeng

    2015-01-01

    Graphical abstract: - Highlights: • The results indicated that aminoalcohols exist with a mixing of intercalation and grafting. • Aminoalcohols can form strong hydrogen bonds with Al octahedral sheet. • The interaction between aminoalcohols and Si tetrahedral sheet are mainly attributed by vdW force. • Aminoalcohols grafting or intercalating on kaolinite have strong reactivity as electron donors. - Abstract: Fundamental problems related to aminoalcohols intercalating on kaolinite were investigated by using density functional theory method. This study examines the adsorption modes of diethanolamine and triethanolamine on kaolinite, the role of hydrogen bonds and van der Waals (vdW) forces between aminoalcohols and interlayer of kaolinite, and the change of molecular orbital occupancies of functionalized kaolinite. Results show that functionalized kaolinite is physically intercalated and covalently grafted by aminoalcohols. Non-covalent interaction analysis provides a visualized description that intercalated aminoalcohols form strong hydrogen bonds with Al octahedral sheet, and the interaction between aminoalcohols and Si tetrahedral sheet is mainly attributed to weak vdW force. The analysis of molecular orbital occupancies for kaolinite complex showed that the functionalized kaolinite has strong chemical reactivity as electron donors on the sites of grafted or intercalated aminoalcohols for further chemical reaction with other materials

  17. Interactions between kaolinite Al−OH surface and sodium hexametaphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yonghua, E-mail: hyh19891102@163.com [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Liu, Wenli; Zhou, Jia [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chen, Jianhua [College of Resources and Metallurgy, Guangxi University, Nanning 530004 (China)

    2016-11-30

    Highlights: • Sodium hexametaphosphate (NaHMP) can adsorb on kaolinite Al−OH terminated (001) surface easily. • The oxygen atoms of hexametaphosphate form strong hydrogen bonds with the hydrogen atoms of kaolinite Al−OH surface. • The electrostatic force is the main interaction between NaHMP and Al−OH surface. • The linear hexaphosphate −[PO{sub 3}]{sub m}− chains adsorb stably than −[HPO{sub 3}]{sub m}− chains. - Abstract: To investigate the dispersion mechanism of sodium hexametaphosphate on kaolinite particles, we simulated the interaction between linear polyphosphate chains and kaolinite Al−OH terminated surface by molecular dynamics, as well as the interaction between the [HPO{sub 4}]{sup 2−} anion and kaolinite Al−OH surface by density functional theory (DFT). The calculated results demonstrate that hexametaphosphate can be adsorbed by the kaolinite Al−OH surface. The oxygen atoms of hexametaphosphate anions may receive many electrons from the Al−OH surface and form hydrogen bonds with the hydrogen atoms of surface hydroxyl groups. Moreover, electrostatic force dominates the interactions between hexametaphosphate anions and kaolinite Al−OH surface. Therefore, after the adsorption of hexametaphosphate on kaolinite Al−OH surface, the kaolinite particles carry more negative charge and the electrostatic repulsion between particles increases. In addition, the adsorption of −[PO{sub 3}]{sub m}− species on the Al−OH surface should be more stable than the adsorption of −[HPO{sub 3}]{sub m}− species.

  18. Growth mechanisms, polytypism, and real structure of kaolinite microcrystals

    International Nuclear Information System (INIS)

    Samotoin, N. D.

    2008-01-01

    The mechanisms of growth of kaolinite microcrystals (0.1-5.0 μm in size) at deposits related to the cluvial weathering crust, as well as to the low-temperature and medium-temperature hydrothermal processes of transformations of minerals in different rocks in Russia, Kazakhstan, Ukraine, Czechia, Vietnam, India, Cuba, and Madagascar, are investigated using transmission electron microscopy and vacuum decoration with gold. It is established that kaolinite microcrystals grow according to two mechanisms: the mechanism of periodic formation of two-dimensional nuclei and the mechanism of spiral growth. The spiral growth of kaolinite microcrystals is dominant and occurs on steps of screw dislocations that differ in sign and magnitude of the Burgers vector along the c axis. The layered growth of kaolinite originates from a widespread source in the form of a step between polar (+ and -) dislocations, i.e., a growth analogue of the Frank-Read dislocation source. The density of growth screw dislocations varies over a wide range and can be as high as ∼10 9 cm -2 . Layered stepped kaolinite growth pyramids for all mechanisms of growth on the (001) face of kaolinite exhibit the main features of the triclinic 1Tc and real structures of this mineral.

  19. Intercalation and Exfoliation of Kaolinite with Sodium Dodecyl Sulfate

    Directory of Open Access Journals (Sweden)

    Xiaochao Zuo

    2018-03-01

    Full Text Available Kaolinite (Kaol was intercalated with dimethyl sulfoxide (DMSO and subsequently methanol (MeOH to prepare intercalation compounds Kaol-DMSO and Kaol-MeOH. Kaol-MeOH was used as an intermediate to synthesize Kaol-sodium dodecyl sulfate (SDS intercalation compound (Kaol-SDS via displacement reaction. The ultrasonic exfoliation of Kaol-SDS produced a resultant Kaol-SDS-U. The samples were characterized by X-ray diffraction (XRD, Fourier transformation infrared spectroscopy (FTIR, thermal analysis, scanning electronic microscopy (SEM, transmission electron microscopy (TEM and particle size analysis. The results revealed that the intercalation of sodium dodecyl sulfate into kaolinite layers caused an obvious increase of the basal spacing from 0.72–4.21 nm. The dehydroxylation temperature of Kaol-SDS was obviously lower than that of original kaolinite. During the intercalation process of sodium dodecyl sulfate, a few kaolinite layers were exfoliated and curled up from the edges of the kaolinite sheets. After sonication treatment, the kaolinite layers were further transformed into nanoscrolls, and the exfoliated resultant Kaol-SDS-U possessed a smaller particle size close to nanoscale.

  20. Thermic Attenuation on Concrete Sidewalk under Urban Trees. Case Study: Santa Marta – Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Devia

    2012-12-01

    Full Text Available Background and Purpose: Urban trees provide a number of services including shade and thermal attenuation. This is related to morphological and physiological characteristics of trees and may vary between species and even between individuals of the same species. The aim of this work was to identify thermic attenuations on concrete sidewalks under six tropical urban trees with six different types of shadows. Material and Methods: In Santa Marta City, Colombia (10º12´20” N, 74º13´33” W, 10 meters above sea level and 31ºC temperature, we selected six trees (species with different types of shade, and they are evaluated for soil temperature and the temperature in the shade and off throughout the day for four different days of the year. ANOVA and t-tests were performed with R program in order to identify the influence of the specie, the day, the hour and the position (at the thermic comfort level, surface temperature on the temperature results obtained. Results and Conclusion: Some trees have the most translucent shadows most likely due to nictinastic movements and consequently less temperature attenuation. On the other hand, other trees have denser shadows and can generate more substantial thermic attenuations. Regarding temperature data, the hour of the day shows the greatest influence on the variability of air temperature and the species shows the greatest influence on the variability of surface temperature. Honey berry (Meliccoca bijugatus and Malay almond (Terminalia atappa trees have denser shadows and can generate more substantial thermic attenuations. Tree physiology can play an important role in temperature attenuation in cities as a result of shadow effects and can be applied as a criterion to select urban trees in tropical cities.

  1. Antifoaming materials in G.S. (Girlder sulfide) heavy water plants. Thermical stability. Pt. 2

    International Nuclear Information System (INIS)

    Delfino, C.A.

    1986-01-01

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2 MPa, up to 230 deg C). About twenty commercial surfactants were studied from the point of view of their thermical stability. (Author) [es

  2. Relationships between thermic effect of food, insulin resistance and autonomic nervous activity

    OpenAIRE

    Watanabe, Tomonori; Nomura, Masahiro; Nakayasu, Kimiko; Kawano, Tomohito; Ito, Susumu; Nakaya, Yutaka

    2006-01-01

    Background: The thermic effect of food (TEF) is higher in lean than in obese human subjects. Objective: Relationships between TEF and insulin resistance during meals, from the point of view of autonomic nervous activity, were evaluated. Methods : Autonomic nervous activity was evaluated in 20 young adults using the spectral analysis of heart rate variability from one hour before to two hours after a meal. Heart rate data were analyzed based on low frequency components (LF power, 0.04 - 0.15Hz...

  3. Thermic solar plants for the production of electricity in Mexico: present and future

    International Nuclear Information System (INIS)

    Almanza, R.

    1990-01-01

    During the last decade, there are have been some important achievements in generating electricity using solar concentrators. The Instituto de Ingenieria, of the Universidad Nacional Autonoma de Mexico (UNAM), has started the design and construction of solar thermic plants for generating electricity , capable of reaching 1 Kw and 10 Kw. The Instituto continues developing the research and testing of new materials, because this way of generating electricity has become economically feasible: besides, it constitutes a non polluting alternative. (Author)

  4. Solid thermoluminescent dosemeter of sodium tetraborate and brazilian fluorite sensible to thermic neutrons

    International Nuclear Information System (INIS)

    Fratin, L.; Cruz, M.T. da

    1987-01-01

    The production of solid thermoluminescent dosemeters sensible to thermic neutrons is described. The stages of the production are described: vitrification of sodium tetraborate, mixture and cold pressing, syntherization. The obtention of a CaF 2 : natural dosemeter with NaCl which presents sensibility to gamma radiation similar to CaF 2 : natural dosemeter with Na 2 B 4 O 7 is studied. (M.A.C.) [pt

  5. Thermic Attenuation on Concrete Sidewalk under Urban Trees. Case Study: Santa Marta – Colombia

    OpenAIRE

    Carlos Devia; Andrés Torres

    2012-01-01

    Background and Purpose: Urban trees provide a number of services including shade and thermal attenuation. This is related to morphological and physiological characteristics of trees and may vary between species and even between individuals of the same species. The aim of this work was to identify thermic attenuations on concrete sidewalks under six tropical urban trees with six different types of shadows. Material and Methods: In Santa Marta City, Colombia (10º12´20” N, 74º13´33” W, 10 met...

  6. National fossil fuels consumption: Estimates of CO2 emissions and thermic pollution

    International Nuclear Information System (INIS)

    Mariani, Mario; Casale, Francesco

    1997-01-01

    The study on the basis of the national energy consumption from 1988 to 1994, estimates CO 2 emission rates produced by the most relevant hydrocarbons involved in the technological combustion processes and assess the potential thermic impact on the environment. Two calculation procedures have been developed taking into account once emission factors and other emission indexes in order to verify the two estimates. Besides, the work determines the national trend of CO 2 emission with regard to the aim for the stabilization of carbon dioxide emissions at 1990 levels by 2000

  7. Charge and Levitation of Grains in Plasma Sheath with Dust Thermic Emission

    International Nuclear Information System (INIS)

    Wu Haicheng; Xie Baisong

    2005-01-01

    By taking into account thermic emission current from hot dust surface, the problem involved in dust charging and levitation of dust grains in plasma sheath has been researched. The results are compared to that without including thermal emission current while the system parameters are same. It is found that the thermal emission current has played a significant role on modifying the dust charging and balance levitations. Both of the charging numbers of dust and the dust radius in balance are dramatically reduced. The stability of dust levitation is also analyzed and discussed.

  8. Considerations on thermic and mechanic processes that appear when 3D printing using ABS fused deposition modelling technology

    Science.gov (United States)

    Amza, Catalin Gheorghe; Niţoi, Dan Florin

    2018-02-01

    3D printers are of recent history, but with an extremely rapid evolution both in technology and hardware involved. At present excellent performances are reached in applications such as 3D printing of various Acrylonitrile butadiene styrene (ABS) plastic parts for house building using Fused Deposition Modelling technology. Nevertheless, the thermic and mechanic processes that appear when manufacturing such plastic components are quite complex. This aspect is very important, especially when one wants to optimize the manufacturing of parts with certain geometrical complexity. The Finite Element Analysis/Modelling (FEA/FEM) is among the few methods that can study the thermic transfer processes and shape modifications that can appear due to non-seamar behavior that takes place when the ABS plastic material is cooling down. The current papers present such an analysis when simulating the deposition of several strings of materials. A thermic analysis is made followed by a study of deformations that appear when the structure cools down.

  9. Typical entanglement

    Science.gov (United States)

    Deelan Cunden, Fabio; Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio

    2013-05-01

    Let a pure state | ψ> be chosen randomly in an NM-dimensional Hilbert space, and consider the reduced density matrix ρ A of an N-dimensional subsystem. The bipartite entanglement properties of | ψ> are encoded in the spectrum of ρ A . By means of a saddle point method and using a "Coulomb gas" model for the eigenvalues, we obtain the typical spectrum of reduced density matrices. We consider the cases of an unbiased ensemble of pure states and of a fixed value of the purity. We finally obtain the eigenvalue distribution by using a statistical mechanics approach based on the introduction of a partition function.

  10. Adsorption properties of stearic acid onto untreated kaolinite | Sari ...

    African Journals Online (AJOL)

    The focus of the study is to investigate adsorption property and determine thermodynamic parameters for the adsorption of stearic acid onto untreated kaolinite at the temperatures of 25, 35 and 45 oC. The equilibrium adsorption isotherms were analyzed by linear Langmuir and Freundlich models. Adsorption experiments ...

  11. Calcination of kaolinite clay particles for cement production

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2014-01-01

    Kaolinite rich clay particles calcined under certain conditions can attain favorable pozzolanic properties and can be used to substitute part of the CO2 intensive clinker in cement production. To better guide calcination of a clay material, a transient one-dimensional single particle model...

  12. Polypropylene-modified kaolinite composites: Effect of chemical ...

    African Journals Online (AJOL)

    PP/kaolinite compounds were prepared by the melt intercalation method. The effects of modified clay on properties of the prepared composites were studied. The XRD results showed that the treatment with the ammonium salt caused the return to the initial state of the clay. The thermogravimetric analysis thermograms (TGA) ...

  13. Modeling of calcination of single kaolinitic clay particle

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    The present work aims at modeling of the calcination (dehydroxylation) process of clay particles, specifically kaolinite, and its thermal transformation. For such purpose, 1D single particle calcination model was developed based on the concept of shrinking core model to assess the dehydroxylation...

  14. Porous Materials from Thermally Activated Kaolinite: Preparation, Characterization and Application

    Directory of Open Access Journals (Sweden)

    Jun Luo

    2017-06-01

    Full Text Available In the present study, porous alumina/silica materials were prepared by selective leaching of silicon/aluminum constituents from thermal-activated kaolinite in inorganic acid or alkali liquor. The correlations between the characteristics of the prepared porous materials and the dissolution properties of activated kaolinite were also investigated. The results show that the specific surface area (SSA of porous alumina/silica increases with silica/alumina dissolution, but without marked change of the BJH pore size. Furthermore, change in pore volume is more dependent on activation temperature. The porous alumina and silica obtained from alkali leaching of kaolinite activated at 1150 °C for 15 min and acid leaching of kaolinite activated at 850 °C for 15 min are mesoporous, with SSAs, BJH pore sizes and pore volumes of 55.8 m2/g and 280.3 m2/g, 6.06 nm and 3.06 nm, 0.1455 mL/g and 0.1945 mL/g, respectively. According to the adsorption tests, porous alumina has superior adsorption capacities for Cu2+, Pb2+ and Cd2+ compared with porous silica and activated carbon. The maximum capacities of porous alumina for Cu2+, Pb2+ and Cd2+ are 134 mg/g, 183 mg/g and 195 mg/g, respectively, at 30 °C.

  15. Adsorption of some radionuclides on kaolinite mineral surface

    International Nuclear Information System (INIS)

    Hafez, M.B.; Said, F.I.A.

    1986-01-01

    Fixation of 187 Cs(I), 144 Ce(III), 90 Sr(II), 233 U(VI), 239 Pu(IV) and 211 Am(III) from aqueous and phosphate media on kaolinite was studied. The fixation of the nuclides on the mineral was found to depend on the pH and the hydrolytic behaviour of the elements

  16. Coagulation processes of kaolinite and montmorillonite in calm, saline water

    Science.gov (United States)

    Zhang, Jin-Feng; Zhang, Qing-He; Maa, Jerome P.-Y.

    2018-03-01

    A three dimensional numerical model for simulating the coagulation processes of colloids has been performed by monitoring the time evolution of particle number concentration, the size distribution of aggregates, the averaged settling velocity, the collision frequency, and the collision efficiency in quiescent water with selected salinities. This model directly simulates all interaction forces between particles based on the lattice Boltzmann method (LBM) and the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and thus, can reveal the collision and coagulation processes of colloidal suspensions. Although using perfect spherical particles in the modeling, the results were compared with those for kaolinite and montmorillonite suspensions to demonstrate the capability of simulating the responses of these particles with highly irregular shape. The averaged settling velocity of kaolinite aggregates in quiescent saline water reached a maximum of 0.16 mm/s when the salinity increasing to about 3, and then, exhibited little dependence on salinity thereafter. Model simulations results (by choosing specific values that represent kaolinite's characteristics) indicate a similar trend: rapid decrease of the particle number concentration (i.e., rapidly flocculated, and thus, settling velocity also increases rapidly) when salinity increases from 0 to 2, and then, only increased slightly when salinity was further increased from 5 to 20. The collision frequency for kaolinite only decreases slightly with increasing salinity because that the fluid density and viscosity increase slightly in sea water. It suggests that the collision efficiency for kaolinite rises rapidly at low salinities and levels off at high salinity. For montmorillonite, the settling velocity of aggregates in quiescent saline water continuedly increases to 0.022 mm/s over the whole salinity range 0-20, and the collision efficiency for montmorillonite rises with increasing salinities.

  17. The effect of resistance exercise on the thermic effect of food.

    Science.gov (United States)

    Denzer, Charlene M; Young, John C

    2003-09-01

    The thermic effect of food (TEF) is the increment in energy expenditure above resting metabolic rate associated with the cost of absorption and processing of food for storage. Previous studies have shown that TEF is enhanced by aerobic endurance exercise of sufficient duration and intensity. The purpose of this study was to determine if a similar effect occurs with a single bout of resistance exercise (weightlifting). VO2 was measured in 9 healthy volunteers (3 males and 6 females) for 2 hours after ingestion of a 2760 kJ (660 kcal) carbohydrate meal with and without prior completion of a resistance training regimen (2 sets of 10 repetitions of 10 different exercises). The meal caused an immediate and persistent thermic effect in both the control and the exercise trial. Mean oxygen consumption over baseline increased 20% in the control trial and 34% in the exercise trial. TEF calculated from VO2 and RER (total area under the response curve above baseline) was 73% greater in the exercise trial compared with the control trial (159 +/- 18 vs. 92 +/- 14 KJ/2 hrs, p carbohydrate meal is enhanced following a single bout of resistance exercise.

  18. Alpine plant distribution and thermic vegetation indicator on Gloria summits in the central Greater Caucasus

    International Nuclear Information System (INIS)

    Gigauri, K.; Abdaladze, O.; Nakhutsrishvili, G

    2016-01-01

    The distribution of plant species within alpine areas is often directly related to climate or climate-influenced ecological factors. Responding to observed changes in plant species, cover and composition on the GLORIA summits in the Central Caucasus, an extensive setup of 1m * 1m permanent plots was established at the treeline-alpine zones and nival ecotone (between 2240 and 3024 m a.s.l.) on the main watershed range of the Central Greater Caucasus nearby the Cross Pass, Kazbegi region, Georgia. Recording was repeated in a representative selection of 64 quadrates in 2008. The local climatic factors - average soil T degree C and growing degree days (GDD) did not show significant increasing trends. For detection of climate warming we used two indices: thermic vegetation indicator S and thermophilization indicator D. They were varying along altitudinal and exposition gradients. The thermic vegetation indicator decrease in all monitoring summits. The abundance rank of the dominant and endemic species did not change during monitoring period. (author)

  19. Cleaning oil refining drainage waters out of emulsified oil products with thermic treated cedar nut shell

    Science.gov (United States)

    Pyatanova, P. A.; Adeeva, L. N.

    2017-08-01

    It was elaborated the ability of the sorbent produced by thermic treatment of cedar nut shell to destruct model and real first kind (direct) emulsions in static and dynamic conditions. In static conditions optimal ratio sorbent-emulsion with the original concentration of oil products 800 mg/l was in the range of 2.0 g per 100 ml of emulsion which corresponds to the level of treatment 94.9%. The time of emulsion destruction was 40 minutes. This sorbent is highly active in dynamic processes of oil-contaminated water treatment, the level of treatment 96.0% is being achieved. Full dynamic sorptive capacity of the sorbent is 0.85 g/g. Sorbent based on the thermic treated cedar nut shell can be elaborated as sorptive filter element of local treatment facilities of oil refining and petrochemical processes. After the treatment with this sorbent of drainage waters of oil refinery in dynamic conditions the concentration of oil products became less than mpc on oil products for waste waters coming to biological treatment.

  20. Earth thermics

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, M

    1960-01-01

    The thermodynamics of the Earth are described, including terrestrial heat flow, internal temperatures and thermal history. The value of the geothermal gradient has been considered to be 3/sup 0/C/100 m but measured values are slightly different. The values of terrestrial heat flow are relatively constant and are calculated be about 2.3 x 10 to the minus 6 cal/cm/sup 2/ sec (2.3 HFU). The Earth's internal temperature can be calculated from the adiabatic temperature gradient of adiabatic expansion. Using Simon's equation No. 9, a value of 2100-2500/sup 0/C is obtained, this is much lower than it was previously thought to be. The value of 2.3 HFU can easily be obtained from this internal temperature figure.

  1. Spectroscopic studies of U(VI) sorption at the kaolinite-water interface. Final report

    International Nuclear Information System (INIS)

    Thompson, H.A.; Parks, G.A.; Brown, G.E. Jr.

    1994-01-01

    Efficient use of U as a resource and safe handling, recycling and disposal of U-containing wastes require an understanding of the factors controlling the fate of U, where fate refers to the destination of U, typically expressed as an environmental medium or a process phase. The sorption process constitutes a change in elemental fate. Partitioning of an element from solution to a solid phase, or sorption, can be divided into three broad categories: adsorption, surface precipitation, and absorption. Extended X-ray absorption fine structure (EXAFS), a type of X-ray absorption spectroscopy (XAS), offers the possibility for distinguishing among different modes of sorption by characterizing the atomic environment of the sorbing element. In this study, the authors use EXAFS to determine the structure of U(VI) sorption complexes at the kaolinite-water interface. In Chapter One, they present an overview of selected aspects of U structural chemistry as a basis for considering the structural environment of U at the solid-water interface. To evaluate the utility of XAS for characterization of the structural environment of U(VI) at the solid-water interface, they have carried out an in-depth analysis of XAS data from U(VI)-containing solid and solution model compounds, which they describe in Chapter Two. In Chapter three, they consider sorption of U by kaolinite as a means of effecting the removal of U from surface collection pond waters on the Rocky Flats Plant site in northern Colorado

  2. Preparation of poly(vinyl alcohol)/kaolinite nanocomposites via in situ polymerization

    International Nuclear Information System (INIS)

    Jia Xin; Li Yanfeng; Zhang Bo; Cheng Qiong; Zhang Shujiang

    2008-01-01

    Poly(vinyl alcohol)/kaolinite intercalated nanocomposites (Kao-PVA) were prepared via in situ intercalation radical polymerization. Vinyl acetate (VAc) was intercalated into kaolinite by a displacement method using dimethyl sulfoxide/kaolinite (Kao-DMSO) as the intermediate. Then, PVAc/kaolinite (Kao-PVAc) was obtained via radical polymerization with benzoyl peroxide (BPO) as initiator. Last, PVAc/kaolinite was saponified via direct-hydrolysis with NaOH solution in order to obtain PVA/kaolinite nanocomposites, which was characterized by Fourier-Transformation spectroscopy (FTIR), wide X-ray diffraction (WXRD) and transmission electron microscopy (TEM). Their differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results of the obtained PVA/kaolinite suggested that the thermal properties had an obvious improvement

  3. Salinity dependence of 226Ra adsorption on montmorillonite and kaolinite

    International Nuclear Information System (INIS)

    Shuji Tamamura; Takahiro Takada; Seiya Nagao; Masayoshi Yamamoto; Keisuke Fukushi

    2014-01-01

    The effect of NaCl concentration (10.0-1,000 mM) on 226 Ra adsorption was investigated in the presence of montmorillonite and kaolinite. A positive correlation was observed between the dissolved 226 Ra and NaCl concentrations in the presence of these adsorbents. Distribution coefficients decreased from the order of 10 4 to 10 0 (mL g -1 ) with an increase in NaCl concentration. Although the coefficients were higher for montmorillonite than kaolinite at lower NaCl concentrations, the trend was reversed at higher NaCl concentrations (≥500 mM) owing to the sharper reduction of the coefficient for montmorillonite with the increase in NaCl concentration. The rapid reduction was ascribed to higher negative charge density of montmorillonite, which leads the Ra 2+ adsorption mechanism to approach charge-compensating ion exchange. (author)

  4. Flocculation kinetics of kaolinite : role of aqueous phase species

    Energy Technology Data Exchange (ETDEWEB)

    House, P.; Wang, C.; Dhadli, N. [Shell Canada Ltd., Calgary, AB (Canada)

    2010-07-01

    Flocculation kinetics were used to study the rate-based processes that lead to aggregate growth and breakage of kaolinite in oil sands tailings. The role of aqueous phase species on aggregate growth, breakage and flocculant de-activation was studied. Collision efficiency and deactivation parameters were presented. The study showed that collisions can be efficient when the adsorption of the polymer is thermodynamically favorable. Up to 94 percent of adsorption takes place at the kaolinite edge. Studies have shown that hydrogen bonding sites on the kaolinite disappear with increases in pH values. The impact of molecular level interactions on flocculation kinetics were assessed in order to determine collision efficiencies and aggregate breakage rates. A focused beam reflectance model was used to monitor flocculation kinetics in situ. The period over which reflectance was observed was coupled with the laser velocity to determine the chord length of the particle. The kinetics of flocculation were observed for a 10 minute period. The effects of pH, calcium additions, and EDTA chelating agent additions were investigated. The study showed that calcium additions accelerate the rate of flocculant growth dramatically, and provide a much higher collision efficiency. Flocculants formed in the presence of calcium were weaker. The presence of salts promoted polymer adsorption by non-specific Van der Waals forces. tabs., figs.

  5. The effect of fast eating on the thermic effect of food in young Japanese women.

    Science.gov (United States)

    Toyama, Kenji; Zhao, Xifan; Kuranuki, Sachi; Oguri, Yasuo; Kashiwa Kato, Eriko; Yoshitake, Yutaka; Nakamura, Teiji

    2015-03-01

    The relationship between eating speed and the thermic effect of food (TEF) remains unclear. We investigated the difference in the TEF when meals containing the same amount of energy were eaten in 5 min (fast eating) or 15 min (regular eating). Subjects were nine non-obese young women. Following a 350 kcal (1464 kJ) meal, energy expenditure and autonomic nervous system activity were measured. The frequency of mastication was also calculated. The TEF for the 15-min period after the start of eating with fast eating was significantly lower than with regular eating (p frequency/high-frequency ratio and TEF at 5-min intervals up to 20 min after the start of eating and between total mastication frequency and TEF during ingestion. Fast eating may reduce the TEF, potentially because a decrease in mastication frequency decreases sympathetic nervous system activity.

  6. Magnesio-thermic reduction of UF4 to uranium metal : plant operating experience

    International Nuclear Information System (INIS)

    Mayekar, S.V.; Singh, H.; Meghal, A.M.; Koppiker, K.S.

    1991-01-01

    Uranium Metal Plant has switched over from calcio-thermy to magnesio-thermy for production of uranium ingots. In this paper, the plant operating experience for magnesio-thermic reduction is described. Based on trials, the production has been stepped up from 40 kg ingots to 200 kg ingots. The operating parameters optimised include : heating schedule, UF 4 quality, magnesium quantity and quality, and particle size. The effect of quality of refractory lining has been discussed. Conditions for lining are optimised with regard to type of material used and size. Developmental work has also been carried out on use of pelletised charge and on use of graphite sleeves. Some experience in the machining of ingots for removal of surface slag is also discussed. Impurity problems, occasionally encountered, have been investigated and results are discussed. Based on the experience gained, specifications for operation have been laid down, and areas for further improvement are identified. (author). 5 refs., 1 fig., 1 tab

  7. Aspects of Energy Metabolism in Mangalitsa Pigs Exposed at Thermic Neutral Temperature

    Directory of Open Access Journals (Sweden)

    Monica Pârvu

    2011-10-01

    Full Text Available The studies aimed the energy metabolism determination in Mangalitsa pigs exposed at thermic neutral temperature, compared to Large White pigs. The experimental period was between 80 and 100 kg liveweight. The animals had free access to standard, isoprotein and isocalory diets, with 13.5% crude protein (CP and 3100 kcal/kg metabolizable energy. Feed intake was measured on a daily basis. The energy-protein balance was calculated on the basis of comparative slaughter made at the beginning and end of the experiment. The metabolizable energy (MEc was estimated by chemical analysis (feed and excreta using mathematical modelling and the Whittemore’s formula. The metabolizable energy utilization efficiency was 0.61 at Large White and 0.53 at Mangalitsa.

  8. Relationships between thermic effect of food, insulin resistance and autonomic nervous activity.

    Science.gov (United States)

    Watanabe, Tomonori; Nomura, Masahiro; Nakayasu, Kimiko; Kawano, Tomohito; Ito, Susumu; Nakaya, Yutaka

    2006-02-01

    The thermic effect of food (TEF) is higher in lean than in obese human subjects. Relationships between TEF and insulin resistance during meals, from the point of view of autonomic nervous activity, were evaluated. Autonomic nervous activity was evaluated in 20 young adults using the spectral analysis of heart rate variability from one hour before to two hours after a meal. Heart rate data were analyzed based on low frequency components (LF power, 0.04-0.15 Hz), high frequency components (HF power, 0.15-0.40 Hz), and LF/HF ratios. Energy expenditure and the TEF were measured 30 min after a meal. Homeostasis model of insulin resistance index (HOMA-IR) was also measured. The LF/HF ratio was significantly increased 30 min after a meal (pinsulin sensitivity induces a poor response of sympathetic nervous activity in the postprandial phase and a reduction in postprandial energy expenditure.

  9. New kaolinite phases expanded through intercalation with potassium acetate

    International Nuclear Information System (INIS)

    Frost, R.L.; Kristof, J.; Kloprogge, J.T.

    1998-01-01

    Full text: Changes in the hydroxyl surfaces of potassium acetate-intercalated kaolinite have been studied over the ambient to predehydroxylation temperature range using a combination of X-ray diffraction and Raman spectroscopy. Upon intercalation, the kaolinite expanded along the c-axis direction to 13.88 Angstroms. Upon heating the intercalation complex over the 50 to 300 deg C range, X-ray diffraction shows the existence of three additional intercalation phases with d-spacings of 9.09, 9.60, and 11.47 Angstroms. The amount of each phase is temperature dependent. These expansions are reversible and upon cooling the intercalation complex returned to its original spacing. The 13.88 Angstroms phase only existed in the presence of water. It is proposed that the expanded kaolinite intercalation phases result from the orientation of the acetate within the intercalation complex. The Raman spectra of the hydroxyl-stretching region (Frost and van der Gaast, 1997) of potassium acetate-intercalated kaolinite has been obtained under an atmosphere of both air and nitrogen using a thermal stage over the 25 to 300 deg C temperature range (Johansson et al., 1998). Raman spectra of the C-C, C=O stretching and O-C-O bending modes show that at least two types of acetate are present in the intercalation complex. These are assigned to two different orientations of the acetate. At 25 deg C, a new band at 3606 cm -1 attributed to the inner surface hydroxyl hydrogen bonded to the acetate ion is observed with a concomitant loss of intensity in the bands attributed to the inner surface hydroxyls (Frost and Kristof, 1997, Frost et al.,1997). Heating the intercalation complex to 50 deg C results in two hydroxyl-stretching frequencies at 3594 and 3604 cm -1 . This change in frequencies is ascribed to phase changes of the potassium acetate-intercalated kaolinite. At 100 deg C, the bands shift to 3600 and 3613 cm -1 . These shifts in frequencies are assigned to new kaolinite expanded phases. At

  10. Effect of high-energy ball milling in the structural and textural properties of kaolinite

    Directory of Open Access Journals (Sweden)

    E. C. Leonel

    2014-06-01

    Full Text Available Through the process of high-energy ball milling it is possible to obtain solid materials with higher surface area and different particle sizes. These characteristics are very important for some application such as adsorption. Besides, applications of some clays depend on the functionalization which, for kaolinite, takes place in the aluminol groups. Modification in the structural and textural properties of kaolinite by high-energy milling can improve functionalization of kaolinite due to the exposure of aluminol groups. In this work studies were done on the influence of high-energy ball milling on the morphological properties of kaolinite, taking into account parameters such as filling of the miller, number of balls and amount of mass to be milled. Moreover, studies involving milling kinetics of purified kaolinite were carried out to verify modification in the morphology of kaolinite with milling time.

  11. Normothermic versus hypothermic cardiopulmonary bypass in children undergoing open heart surgery (thermic-2): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Baos, Sarah; Sheehan, Karen; Culliford, Lucy; Pike, Katie; Ellis, Lucy; Parry, Andrew J; Stoica, Serban; Ghorbel, Mohamed T; Caputo, Massimo; Rogers, Chris A

    2015-05-25

    During open heart surgery, patients are connected to a heart-lung bypass machine that pumps blood around the body ("perfusion") while the heart is stopped. Typically the blood is cooled during this procedure ("hypothermia") and warmed to normal body temperature once the operation has been completed. The main rationale for "whole body cooling" is to protect organs such as the brain, kidneys, lungs, and heart from injury during bypass by reducing the body's metabolic rate and decreasing oxygen consumption. However, hypothermic perfusion also has disadvantages that can contribute toward an extended postoperative hospital stay. Research in adults and small randomized controlled trials in children suggest some benefits to keeping the blood at normal body temperature throughout surgery ("normothermia"). However, the two techniques have not been extensively compared in children. The Thermic-2 study will test the hypothesis that the whole body inflammatory response to the nonphysiological bypass and its detrimental effects on different organ functions may be attenuated by maintaining the body at 35°C-37°C (normothermic) rather than 28°C (hypothermic) during pediatric complex open heart surgery. This is a single-center, randomized controlled trial comparing the effectiveness and acceptability of normothermic versus hypothermic bypass in 141 children with congenital heart disease undergoing open heart surgery. Children having scheduled surgery to repair a heart defect not requiring deep hypothermic circulatory arrest represent the target study population. The co-primary clinical outcomes are duration of inotropic support, intubation time, and postoperative hospital stay. Secondary outcomes are in-hospital mortality and morbidity, blood loss and transfusion requirements, pre- and post-operative echocardiographic findings, routine blood gas and blood test results, renal function, cerebral function, regional oxygen saturation of blood in the cerebral cortex, assessment of

  12. Kaolinite flocculation induced by smectite addition - a transmission X-ray microscopic study.

    Science.gov (United States)

    Zbik, Marek S; Song, Yen-Fang; Frost, Ray L

    2010-09-01

    The influence of smectite addition on kaolinite suspensions in water was investigated by transmission X-ray microscopy (TXM) and Scanning Electron Microscopy (SEM). Sedimentation test screening was also conducted. Micrographs were processed by the STatistic IMage Analysing (STIMAN) program and structural parameters were calculated. From the results of the sedimentation tests important influences of small smectite additions to about 3wt.% on kaolinite suspension flocculation has been found. In order to determine the reason for this smectite impact on kaolinite suspension, macroscopic behaviour micro-structural examination using Transmission X-ray Microscope (TXM) and SEM has been undertaken. TXM & SEM micrographs of freeze-dried kaolinite-smectite suspensions with up to 20% smectite showed a high degree of orientation of the fabric made of highly oriented particles and greatest density when 3wt.% of smectite was added to the 10wt.% dense kaolinite suspension. In contrast, suspensions containing pure kaolinite do not show such platelet mutual orientation but homogenous network of randomly oriented kaolinite platelets. This suggests that in kaolinite-smectite suspensions, smectite forms highly oriented basic framework into which kaolinite platelets may bond in face to face preferential contacts strengthening structure and allowing them to show plastic behaviour which is cause of platelets orientation. Copyright 2010 Elsevier Inc. All rights reserved.

  13. Antifoaming materials studies in G.S. (Girlder sulfide) heavy water plants. Chemical and thermical stability. Pt. 3

    International Nuclear Information System (INIS)

    Delfino, C.A.; Rojo, E.A.

    1988-01-01

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2 MPa, up to 230 deg C). Five commercial surfactants were studied from the point of view of their chemical and thermical stability in order to select the most suitable. (Author) [es

  14. Combined experimental and theoretical investigation of interactions between kaolinite inner surface and intercalated dimethyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuai [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Liu, Qinfu, E-mail: lqf@cumtb.edu.cn [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Cheng, Hongfei [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Zeng, Fangui [Department of Earth Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2015-03-15

    Graphical abstract: Snapshot of the kaolinite–DMSO system after equilibrium is reached. - Highlights: • Dimethyl sulfoxide arranges a monolayer structure between kaolinite layers. • Weak hydrogen bonds exist between methyl groups of dimethyl sulfoxide and kaolinite silica layer. • Intercalated dimethyl sulfoxide forms strong hydrogen bonds with kaolinite alumina layer. - Abstract: Kaolinite intercalation complex with dimethyl sulfoxide (DMSO) was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry–differential scanning calorimetry (TG–DSC) combined with molecular dynamics simulation. The bands assigned to the OH stretching of inner surface of kaolinite were significantly perturbed after intercalation of DMSO into kaolinite. Additionally, the bands attributed to the vibration of gibbsite-like layers of kaolinite shifted to the lower wave number, indicating that the intercalated DMSO were strongly hydrogen bonded to the alumina octahedral surface of kaolinite. The slightly decreased intensity of 1031 cm{sup −1} and 1016 cm{sup −1} band due to the in-plane vibration of Si−O of kaolinite revealed that some DMSO molecules formed weak hydrogen bonds with the silicon tetrahedral surface of kaolinite. Based on the TG result of kaolinite–DMSO intercalation complex, the formula of A1{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}(DMSO){sub 0.7} was obtained, with which the kaolinite–DMSO complex model was constructed. The molecular dynamics simulation of kaolinite–DMSO complex directly confirmed the monolayer structure of DMSO in interlayer space of kaolinite, where the DMSO arranged almost parallel with kaolinite basal surface with all methyl groups being distributed near the interlayer midplane and oxygen atoms orienting toward to the alumina octahedral surface. The radial distribution function between kaolinite and intercalated DMSO verified the strong hydrogen bonds forming between hydroxyl hydrogen

  15. Hybrid materials of kaolinite clay with polypyrrole and polyaniline.

    Science.gov (United States)

    Burridge, Kerstin A; Johnston, James H; Borrmann, Thomas

    2009-12-01

    Composites of the alumino silicate mineral kaolinite, with the conducting polymers polypyrrole and polyaniline have been successfully synthesised. In doing so hybrid materials have been produced in which the high surface area of the mineral is retained, whilst also incorporating the desired chemical and physical properties of the polymer. Scanning electron microscopy shows polypyrrole coatings to comprise of individual polymer spheres, approximately 10 to 15 nm in diameter. The average size of the polymer spheres of polyaniline was observed to be approximately 5 nm in diameter. These spheres fuse together in a continuous sheet to coat the kaolinite platelets in their entirety. The reduction of silver ions to metallic silver nanoparticles onto the redox active surface of the polymers has also been successful, and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterization of the hybrid materials has been undertaken through scanning electron microscopy, energy dispersive spectroscopy, electrical conductivity, cyclic voltammetry, X-ray diffraction, infra red spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and the testing of their anti-microbial activity.

  16. {alpha}-Pinene conversion by modified-kaolinitic clay

    Energy Technology Data Exchange (ETDEWEB)

    Volzone, C. [CETMIC-Centro de Tecnologia de Recursos Minerales y Ceramica-(CONICET-CIC), C.C. 49, Cno. Centenario y 506 (1897) M.B. Gonnet, Prov., Buenos Aires (Argentina)]. E-mail: volzcris@netverk.com.ar; Masini, O. [INTEQUI (CONICET-UNSL), Facultad de Ingenieria y Ciencias Economico Sociales, 25 de Mayo 384, V. Mercedes, Prov., San Luis (Argentina); Comelli, N.A. [INTEQUI (CONICET-UNSL), Facultad de Ingenieria y Ciencias Economico Sociales, 25 de Mayo 384, V. Mercedes, Prov., San Luis (Argentina); Grzona, L.M. [INTEQUI (CONICET-UNSL), Facultad de Ingenieria y Ciencias Economico Sociales, 25 de Mayo 384, V. Mercedes, Prov., San Luis (Argentina); Ponzi, E.N. [CINDECA (CONICET-UNLP) calle 47 No. 257 (1900) La Plata, Prov., Buenos Aires (Argentina); Ponzi, M.I. [INTEQUI (CONICET-UNSL), Facultad de Ingenieria y Ciencias Economico Sociales, 25 de Mayo 384, V. Mercedes, Prov., San Luis (Argentina)

    2005-10-15

    The isomerization of {alpha}-pinene using natural kaolinitic clay before and after different treatments was studied in this work. The kaolinite is a clay material constituted by phyllosilicate 1:1 layer (one sheet of tetrahedral silicon and one sheet of octahedral alumina). The clay was treated at different times using 6.0 N solution of sulfuric acid previous heating to 500 or 700 K. The materials were characterized by X-ray diffraction, by chemical analyses and acidity measurements. The catalytic reactions were carried out at 373 K in a reactor batch with condenser and stirrer. Samples were taken at regular intervals, and reactants and products were quantitatively analyzed with a gas chromatograph after separation of the individual compounds. Conversions of alpha pinene between 67 and 94%, and selectivities in camphene and in limonene of 65 and 23%, respectively, were obtained with the clay treated at different conditions. The structural and textural changes of the clay by the treatments influenced on catalytic reactions.

  17. Hydrometallurgical extraction of Al and Si from kaolinitic clays

    Directory of Open Access Journals (Sweden)

    Eliana G. Pinna

    Full Text Available Abstract Herein is presented the results of a study on the hydrometallurgic extraction and recovery of aluminum and silicon by leaching of kaolinitic clays with HF. The studied extraction parameters were: temperature, reaction time, solid/liquid ratio, concentration, and precipitating agent mass. In the leaching process, mineral dissolutions near 100% were obtained when working at 348 K, solid/liquid ratio 2% w/v, HF 12% v/v, for 120 minutes. The HF leach liquor generated from the dissolution of kaolinitic clays contains H2SiF6and H3AlF6. Studies were conducted to recover the two valuable fluorides as K2SiF6and Na3AlF6by precipitation with alkaline salts from the leach liquor. Phases of precipitated fluorides were identified by XRD and surface morphology by SEM. The purity of the K2SiF6precipitate was 98.8%, whereas for Na3AlF6, it was 89.3%. Also, both synthesized solids are of high commercial value due to their industrial applications.

  18. Intensified Pozzolanic Reaction on Kaolinite Clay-Based Mortar

    Directory of Open Access Journals (Sweden)

    Yang-Hee Kwon

    2017-05-01

    Full Text Available The objective of this study is to develop and characterize kaolinite clay-based structural mortar. The pozzolanic reaction induced from two mineral additives, i.e., calcium hydroxide and silica fume (SF, and the physical filling effect from SF, were found to be effective on the enhancement of structural properties. Based on several preliminary experiments, 7:3 ratio of kaolinite clay/calcium hydroxide was selected as a basic binder. Then, the amount of SF was chosen as 0%, 7.5%, and 15% of the total binder to consider both the chemical and physical effects. The results showed that compressive strengths of samples with 7.5% and 15% SF are significantly increased by approximately 200% and 350%, respectively, at 28 days compared to the sample without SF. However, based on the results of the sample with 15% SF, it is found that excessive addition of SF causes long-term strength loss, possibly owing to micro cracks. With the careful consideration on this long-term behavior, this suggested new mix design can be further extended to develop sustainable structural materials using natural minerals or waste materials with nonbinding properties.

  19. α-Pinene conversion by modified-kaolinitic clay

    International Nuclear Information System (INIS)

    Volzone, C.; Masini, O.; Comelli, N.A.; Grzona, L.M.; Ponzi, E.N.; Ponzi, M.I.

    2005-01-01

    The isomerization of α-pinene using natural kaolinitic clay before and after different treatments was studied in this work. The kaolinite is a clay material constituted by phyllosilicate 1:1 layer (one sheet of tetrahedral silicon and one sheet of octahedral alumina). The clay was treated at different times using 6.0 N solution of sulfuric acid previous heating to 500 or 700 K. The materials were characterized by X-ray diffraction, by chemical analyses and acidity measurements. The catalytic reactions were carried out at 373 K in a reactor batch with condenser and stirrer. Samples were taken at regular intervals, and reactants and products were quantitatively analyzed with a gas chromatograph after separation of the individual compounds. Conversions of alpha pinene between 67 and 94%, and selectivities in camphene and in limonene of 65 and 23%, respectively, were obtained with the clay treated at different conditions. The structural and textural changes of the clay by the treatments influenced on catalytic reactions

  20. Reinforcement of the radiative and thermic stresses of the grape vine. Repercussions on yeast surface microflora

    Directory of Open Access Journals (Sweden)

    Jean-Michel Salmon

    1997-12-01

    Full Text Available All along the ripening period, the radiative and thermic stresses of the grapevine may be reinforced by the use of a reflective soil cover (aluminized film. Such a treatment leads to repercussions on the berries, on the must composition and finally on the wine quality. During such a preliminary experiment, we demonstrated that the temperature increase and/or the reinforcement of the reflected ultraviolet radiations (measured at 254 nm at the level of grape berries severely impaired the development of yeast cells at their surfaces. By means of an artificial inoculation of grapes at the beginning of the ripening period with a mixture of four different yeast genera (Saccharomyces cerevisiae, Hanseniaspora uvarum, Pichiafermentans and Schizosaccharomyces pombe, we demonstrated that the repartition of yeast genera amongst this population was affected by the treatment of stocks with the aluminized film: during the experiment presented in this paper, the Saccharomyces genus was favoured. One may consider by extension similar effects resulting from the reflective properties of some natural soils. Such effects may considerably influence the distribution of wild yeast flora during the spontaneous fermentation of musts. If such an hypothesis is confirmed at a local or regional level, it will represent a first significant piece of the definition of one of the aspects of the" terroir" effect on the characteristics of wines.

  1. Reinforcement of the radiative and thermic stresses of the grapevine. Repercussions on yeast surface microflora

    International Nuclear Information System (INIS)

    Salmon, J.M.; Mailhac, N.; Sauvage, F.X.; Biron, M.J.; Robin, J.P.

    1997-01-01

    All along the ripening period, the radiative and thermic stresses of the grapevine may be reinforced by the use of a reflective soil cover (aluminized film). Such a treatment leads to repercussions on the berries, on the must composition and finally on the wine quality. During such a preliminary experiment, we demonstrated that the temperature increase and/or the reinforcement of the reflected ultraviolet radiations (measured at 254 nm) at the level of grape berries severely impaired the development of yeast cells at their surfaces. By means of an artificial inoculation of grapes at the beginning of the ripening period with a mixture of four different yeast genera (Saccharomyces cerevisiae, Hanseniaspora uvarum, Pichia fermentans and Schizosaccharomyces pombe), we demonstrated that the repartition of yeast genera amongst this population was affected by the treatment of stocks with the aluminized film: during the experiment presented in this paper, the Saccharomyces genus was favoured. One may consider by extension similar effects resulting from the reflective properties of some natural soils. Such effects may considerably influence the distribution of wild yeast flora during the spontaneous fermentation of musts. If such an hypothesis is confirmed at a local or regional level, it will represent a first significant piece of the definition of one of the aspects of the ''terroir'' effect on the characteristics of wines [fr

  2. Formation and Transformation of Iron Oxide-Kaolinite Associations in the Presence of Iron(II)

    NARCIS (Netherlands)

    Wei, S.Y.; Liu, F.; Feng, X.H.; Tan, W.F.; Koopal, L.K.

    2011-01-01

    Iron oxide-kaolinite associations are important components of tropical and subtropical soils and have significant influence on the physical and chemical properties of soils. In this study, the formation and transformation of Fe oxide-kaolinite associations as a function of pH, temperature, and time

  3. Micaceous occlusions in kaolinite observed by ultramicrotomy and high resolution electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S Y [Univ. of Wisconsin, Madison; Jackson, M L; Brown, J L

    1975-01-01

    The layer structure of kaolinite from Twiggs, Georgia, and fire-clay type kaolinite (Frantex B, from France, particle size separates 2 0.2 ..mu..m was studied by high resolution electron microscopy after embedment in Spurr low-viscosity Epoxy media and thin sectioning normal to the (001) planes by an ultramicrotome. Images of the (001) planes (viewed edge-on) of both kaolinites were spaced at 7 A and generally aligned in parallel, with occasional bending into more widely spaced images of about 10 A interval. Some of the 10 A images converged to 7 A at one or both ends, forming ellipse-shaped islands 80 to 130 A thick and 300 to 500 A long. The island areas and interleaved 10 A layers between 7 A layers may represent a residue of incomplete weathering of mica to kaolinite. The proportions of micaceous occlusions were too small and the layer sequences too irregular to be detected by X-ray diffraction. The lateral continuity of the layers through the 7-10-7 A sequence in a kaolinite particle would partially interrupt or prevent expansion in dimethyl sulfoxide (DMSO) and other kaolinite intercalating media. Discrete mica particles were also observed with parallel images at 10 A, as impurities in both kaolinites. The small K content of the chemical analyses of the kaolinite samples is accounted for as interlayer K, not only in discrete mica particles but also in the micaceous occlusions.

  4. Estimation of silver in Ag-meta kaolinite by neutron activation

    International Nuclear Information System (INIS)

    Daniels, E.A.; Rao, S.M.

    1981-01-01

    The present work is based on the neutron activation of Ag-meta kaolinite for the determination of its silver content from the β-activity of the compound using standard tables which showed the percentage of silver in mixtures of silver nitrate and meta kaolinite of known composition against β-activity of the mixture activated under identical conditions. (author)

  5. Acidity of edge surface sites of montmorillonite and kaolinite

    Science.gov (United States)

    Liu, Xiandong; Lu, Xiancai; Sprik, Michiel; Cheng, Jun; Meijer, Evert Jan; Wang, Rucheng

    2013-09-01

    Acid-base chemistry of clay minerals is central to their interfacial properties, but up to now a quantitative understanding on the surface acidity is still lacking. In this study, with first principles molecular dynamics (FPMD) based vertical energy gap technique, we calculate the acidity constants of surface groups on (0 1 0)-type edges of montmorillonite and kaolinite, which are representatives of 2:1 and 1:1-type clay minerals, respectively. It shows that tbnd Si-OH and tbnd Al-OH2OH groups of kaolinite have pKas of 6.9 and 5.7 and those of montmorillonite have pKas of 7.0 and 8.3, respectively. For each mineral, the calculated pKas are consistent with the experimental ranges derived from fittings of titration curves, indicating that tbnd Si-OH and tbnd Al-OH2OH groups are the major acidic sites responsible to pH-dependent experimental observations. The effect of Mg substitution in montmorillonite is investigated and it is found that Mg substitution increases the pKas of the neighboring tbnd Si-OH and tbnd Si-OH2 groups by 2-3 pKa units. Furthermore, our calculation shows that the pKa of edge tbnd Mg-(OH2)2 is as high as 13.2, indicating the protonated state dominates under common pH. Together with previous adsorption experiments, our derived acidity constants suggest that tbnd Si-O- and tbnd Al-(OH)2 groups are the most probable edge sites for complexing heavy metal cations.

  6. Effect of meal frequency on the thermic effect of food in women.

    Science.gov (United States)

    Kinabo, J L; Durnin, J V

    1990-05-01

    The effect of meal frequency on the thermic effect of food (TEF), also referred to as dietary induced thermogenesis (DIT), was investigated in eighteen non-obese female subjects. Their metabolic rate before and after consuming the test meal was measured by open circuit indirect calorimetry using the Douglas bag technique, while the subjects were in the resting state (lying down). Eight subjects consumed a high carbohydrate-low fat (HCLF) meal providing 70, 19 and 11 per cent of the energy content from carbohydrate, fat and protein, respectively, and ten other subjects consumed a low carbohydrate-high fat (LCHF) meal providing 24, 65 and 11 per cent of the energy from carbohydrate, fat and protein, respectively. On two separate occasions, each subject consumed the appropriate diet either as one large meal containing 5040 kJ (1200 kcal) or as two smaller meals each containing 2520 kJ (600 kcal). TEF values were calculated for 6 h after the test meal and the mean values after consuming the HCLF meal were 377.0 +/- 30.0 kJ (90 +/- 7.2 kcal) and 381.0 +/- 26.5 kJ (91.0 +/- 6.3 kcal) for the one meal and the two meals, respectively. The mean TEF values for the subjects who consumed the LCHF meal wre 356.0 +/- 23.0 kJ (85.0 +/- 5.5 kcal) and 340 +/- 15.9 kJ (81.0 +/- 3.8 kcal) for the one meal and the two meals, respectively. No significant differences were found between the two feeding regimens (HCLF, P = 0.94; LCHF, P = 0.64) as well as between the compositions (P = 0.57). Thus, meal frequency and meal composition did not seem to influence the TEF.

  7. Electrochemical investigation of thermically treated graphene oxides as electrode materials for vanadium redox flow battery

    International Nuclear Information System (INIS)

    Di Blasi, O.; Briguglio, N.; Busacca, C.; Ferraro, M.; Antonucci, V.; Di Blasi, A.

    2015-01-01

    Highlights: • Graphene oxide is synthesized at high temperatures in a reducing environment. • Treated graphene oxide-based electrodes are prepared by the wet impregnation method. • Electrochemical performance is evaluated as a function of the physico-chemical properties. - Abstract: Thermically treated graphene oxides (TT-GOs) are synthesized at different temperatures, 100 °C, 150 °C, 200 °C and 300 °C in a reducing environment (20% H 2 /He) and investigated as electrode materials for vanadium redox flow battery (VRFB) applications. The treated graphene oxide-based electrodes are prepared by the wet impregnation method using carbon felt (CF) as support. The main aim is to achieve a suitable distribution of the dispersed graphene oxides on the CF surface in order to investigate the electrocatalytic activity for the VO 2+ /VO 2 + and V 2+ /V 3+ redox reactions in the perspective of a feasible large area electrodes scale-up for battery configuration of practical interest. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are carried out in a three electrode half-cell to characterize the electrochemical properties of the TT-GO-based electrodes. Physico-chemical characterizations are carried out to corroborate the electrochemical results. The TT-GO sample treated at 100 °C (TT-GO-100) shows the highest electrocatalytic activity in terms of peak to peak separation (ΔE = 0.03 V) and current density intensity (∼0.24 A cm −2 at 30 mV/s) both toward the VO 2+ /VO 2 + and V 2+ /V 3+ redox reactions. This result is correlated to the presence of hydroxyl (−OH) and carboxyl (−COOH) species that act as active sites. A valid candidate is individuated as effective anode and cathode electrode in the perspective of electrodes scale-up for battery configuration of practical interest

  8. Optimization of uranyl ions removal from aqueous solution by natural and modified kaolinites

    Energy Technology Data Exchange (ETDEWEB)

    Elhefnawy, O.A.; Elabd, A.A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Nuclear Safeguards and Physical Protection Dept.

    2017-10-01

    The paper addresses the modifications of the most common mineral clay ''kaolinite'' for U(VI) removal from aqueous solutions. A new modified Egyptian natural kaolinite (Ca-MK) was prepared by coating kaolinite with calcium oxide. Another modification process was utilized by calcination and acid activation of kaolinite (E-MK). The Egyptian natural kaolinite (E-NK) and the two modified kaolinites were characterized by different techniques SEM, EDX, XRD, and FTIR. The removal process were investigated in batch experiments as a function of pH, contact time, initial U(VI) concentration, effect of temperature, and recovery of U(VI) were studied. The equilibrium stage was achieved after 60 min and the kinetic data was described well by pseudo-second order model. Isothermal data was better described by the Langmuir isotherm model, indicating the homogeneous removal process. Also the removal process was studied on different temperature 293, 313, and 323 K. The thermodynamic parameters ΔH , ΔS , and ΔG were calculated. The thermodynamic results pointed to the endothermic and favorable nature of the U(VI) removal process in the three kaolinite adsorbents. This study indicated that (Ca-MK) has higher CEC and can be used as a new adsorbent for highly efficient removal of U(VI) from aqueous solutions.

  9. Formation of intercalation compound of kaolinite-glycine via displacing guest water by glycine.

    Science.gov (United States)

    Zheng, Wan; Zhou, Jing; Zhang, Zhenqian; Chen, Likun; Zhang, Zhongfei; Li, Yong; Ma, Ning; Du, Piyi

    2014-10-15

    The kaolinite-glycine intercalation compound was successfully formed by displacing intercalated guest water molecules in kaolinite hydrate as a precursor. The microstructure of the compound was characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope. Results show that glycine can only be intercalated into hydrated kaolinite to form glycine-kaolinite by utilizing water molecules as a transition phase. The intercalated glycine molecules were squeezed partially into the ditrigonal holes in the silicate layer, resulting in the interlayer distance of kaolinite reaching 1.03nm. The proper intercalation temperature range was between 20°C and 80°C. An intercalation time of 24h or above was necessary to ensure the complete formation of kaolinite-glycine. The highest intercalation degree of about 84% appeared when the system was reacted at the temperature of 80°C for 48h. There were two activation energies for the intercalation of glycine into kaolinite, one being 21kJ/mol within the temperature range of 20-65°C and the other 5.8kJ/mol between 65°C and 80°C. The intercalation degree (N) and intercalation velocity (v) of as a function of intercalation time (t) can be empirically expressed as N=-79.35e(-)(t)(/14.8)+80.1 and v=5.37e(-)(t)(/14.8), respectively. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Theoretical experimental study of the factors that govern the molybdenum absorption signal by means of electro thermic atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Garaboto Farfan, M. A.

    1996-01-01

    The formation of molybdenum carbides in the atomizer, used in the electro thermic atomic absorption spectroscopy, is responsible for incomplete analyte removal in its analysis. This generates the apparition of the memory effect and little precision in the results. In this work, different variables that could affect the molybdenum absorption sign were investigated, as well as the influence of hydrochloric acid on the memory effect, by means of studies in the different stages: drying, calcination and atomization, and the samples deposition order in molybdenum solutions, either acidified or not acidified [es

  11. Impact of phenylketonuria type meal on appetite, thermic effect of feeding and postprandial fat oxidation.

    Science.gov (United States)

    Alfheeaid, Hani; Gerasimidis, Konstantinos; Năstase, Ana-Maria; Elhauge, Mie; Cochrane, Barbara; Malkova, Dalia

    2017-03-08

    Dietary management of phenylketonuria (PKU) requires the replacement of natural protein-containing foods with special low protein foods. The effect of a PKU type diet on factors contributing to energy balance requires investigation. To investigate the impact of a PKU type meal on appetite ratings, gut appetite hormones, thermic effect of feeding (TEF) and fat oxidation. Twenty-three healthy adults (mean ± SD age: 24.3 ± 5.1 years; BMI: 22.4 ± 2.5 kg/m 2 ) participated in a randomized, crossover design study. Each participant conducted two (PKU and Control) experimental trials which involved consumption of a PKU type meal and protein substitute drink or an isocaloric and weight matched ordinary meal and protein-enriched milk. Appetite, metabolic rate, fat oxidation measurements and blood collections were conducted for the duration of 300 min. On the completion of the measurements ad libitum buffet dinner was served. Responses of appetite ratings, plasma concentrations of GLP-1 and PYY (P > 0.05, trial effect, two-way ANOVA) and energy intake during ad libitum buffet dinner (P > 0.05, paired t-test) were not significantly different between the two trials. The TEF (PKU, 10.2 ± 1.5%; Control, 13.2 ± 1.0%) and the total amount of fat oxidized (PKU, 18.90 ± 1.10 g; Control, 22.10 ± 1.10 g) were significantly (P meal period. Consumption of a meal composed of special low protein foods has no detrimental impact on appetite and appetite hormones but produces a lower TEF and postprandial fat oxidation than an ordinary meal. These metabolic alterations may contribute to the increased prevalence of obesity reported in patients with PKU on contemporary dietary management. The trial has been registered in ClinicalTrials as NCT02440932. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Flotation of kaolinite from tailings of kaolin-washing plants by cationic collectors

    OpenAIRE

    Barani Kianoush

    2016-01-01

    Traditional processing of kaolin is achieved by dispersion of the mined ore and classification by means of multistage hydrocyclones. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back to the quarry. In this research recovery of kaolinite from tailings of the Zonoupz kaolin washing plant, which is located in Iran, was investigated by cationic flotation. Flotation experiments showed that flotation of kaolinite from tailings was much better in an ac...

  13. Recovery of kaolinite from tailings of Zonouz kaolin-washing plant by flotation-flocculation method

    OpenAIRE

    Kianoush Barani; Masoud Kalantari

    2018-01-01

    The traditional processing of kaolin is achieved by dispersion of the mined ore and classification by multistage hydrocyclone plants. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back into the quarry. In this research, recovery of kaolinite from tailings of Zonouz kaolin washing plant, which is located in Iran was investigated by flotation and flotation- flocculation. Flotation experiments show that the flotation of kaolinite from the tailings i...

  14. Kaolinite Nanocomposite Platelets Synthesized by Intercalation and Imidization of Poly(styrene-co-maleic anhydride

    Directory of Open Access Journals (Sweden)

    Pieter Samyn

    2015-07-01

    Full Text Available A synthesis route is presented for the subsequent intercalation, exfoliation and surface modification of kaolinite (Kln by an imidization reaction of high-molecular weight poly(styrene-co-maleic anhydride or SMA in the presence of ammonium hydroxide. In a first step, the intercalation of ammonolyzed SMA by guest displacement of intercalated dimethylsulfoxide has been proven. In a second step, the imidization of ammonolyzed SMA at 160 °C results in exfoliation of the kaolinite layers and deposition of poly(styrene-co-maleimide or SMI nanoparticles onto the kaolinite surfaces. Compared with a physical mixture of Kln/SMI, the chemically reacted Kln/SMI provides more efficient exfoliation and hydrogen bonding between the nanoparticles and the kaolinite. The kaolinite nanocomposite particles are synthesized in aqueous dispersion with solid content of 65 wt %. The intercalation and exfoliation are optimized for a concentration ratio of Kln/SMI = 70:30, resulting in maximum intercalation and interlayer distance in combination with highest imide content. After thermal curing at 135 °C, the imidization proceeds towards a maximum conversion of the intermediate amic acid moieties. The changes in O–H stretching and kaolinite lattice vibrations have been illustrated by infrared and FT-Raman spectroscopy, which allow for a good quantification of concentration and imidization effects.

  15. Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

    Directory of Open Access Journals (Sweden)

    Hayami Takeda

    2013-05-01

    Full Text Available Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three kinds of kaolinite. The kaolinitic clays were first calcined at 700 °C for 3 h to transform into the amorphous aluminosilicate phases. Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types of zeolite and different compressive strength. This study investigated the effects of the initial kaolinitic clays on the amount and types of zeolite in the resultant geopolymers as well as the strength of the bulk materials. The kaolinitic clays and their metakaolin were characterized by XRD analysis, chemical composition, crystallite size, 29Si and 27Al MAS NMR analysis, and specific surface area measurements. The correlation between the amount of zeolite formed and the compressive strength of the resultant hybrid bulk materials, previously reported by other researchers was not positively observed. In the studied systems, the effects of Si/Al and crystalline size were observed. When the atomic ratio of Si/Al in the starting kaolinitic clays increased, the compressive strength of the hybrid bulk materials increased. The crystallite size of the zeolite in the hybrid bulk materials increased with decreasing compressive strength of the hybrid bulk materials.

  16. Equilibrium and kinetic studies for the sorption of 3-methoxybenzaldehyde on activated kaolinites

    Energy Technology Data Exchange (ETDEWEB)

    Koyuncu, Huelya [Forensic Medicine Foundation, Nasuhpasa Bath Street, No. 12, 16010 Heykel, Bursa (Turkey)]. E-mail: hkoyuncu@yyu.edu.tr; Kul, Ali Riza [Yuzuncu Yil University, Faculty of Art and Science, Department of Chemistry, 65080 Van (Turkey)]. E-mail: alirizakul@yyu.edu.tr; Yildiz, Nuray [Ankara University, Faculty of Engineering, Department of Chemical Engineering, 06100 Tandogan, Ankara (Turkey)]. E-mail: nyildiz@eng.ankara.edu.tr; Calimli, Ayla [Ankara University, Faculty of Engineering, Department of Chemical Engineering, 06100 Tandogan, Ankara (Turkey)]. E-mail: calimli@eng.ankara.edu.tr; Ceylan, Hasan [Yuzuncu Yil University, Faculty of Art and Science, Department of Chemistry, 65080 Van (Turkey)]. E-mail: hceylan@yyu.edu.tr

    2007-03-06

    The sorption of 3-methoxybenzaldehyde on activated kaolinites has been investigated at different temperatures. Two types of activation tests were performed. The sorption equilibrium was studied by sorption isotherms in the temperature range 303-333 K for natural (untreated), thermally and acid activated kaolinites. It was shown that the isotherm shapes were not affected by temperature and activation types of kaolinite. The absorbance data at 312 nm were fitted reasonably well with the Langmuir and Freundlich isotherm models and the model parameters were determined for different temperatures. Thermodynamic quantities such as Gibbs free energy ({delta}G), the enthalpy ({delta}H) and the entropy change of sorption ({delta}S) were determined for natural, thermally and acid activated kaolinites. It was shown that the sorption processes were an endothermic reactions, controlled by physical mechanisms and spontaneously. Adsorption capacity of acid activated kaolinite for 3-methoxybenzaldehyde was higher compared to that of natural and thermally activated kaolinites at various temperatures. The adsorption and desorption rate constants (k {sub a} and k {sub d}) were obtained separately by applying a geometric approach to the first order Langmuir model. This method provided good conformity between the K from Langmuir parameters and K {sub geo} (k {sub a}/k {sub d}) from geometric approach.

  17. Equilibrium and kinetic studies for the sorption of 3-methoxybenzaldehyde on activated kaolinites

    International Nuclear Information System (INIS)

    Koyuncu, Huelya; Kul, Ali Riza; Yildiz, Nuray; Calimli, Ayla; Ceylan, Hasan

    2007-01-01

    The sorption of 3-methoxybenzaldehyde on activated kaolinites has been investigated at different temperatures. Two types of activation tests were performed. The sorption equilibrium was studied by sorption isotherms in the temperature range 303-333 K for natural (untreated), thermally and acid activated kaolinites. It was shown that the isotherm shapes were not affected by temperature and activation types of kaolinite. The absorbance data at 312 nm were fitted reasonably well with the Langmuir and Freundlich isotherm models and the model parameters were determined for different temperatures. Thermodynamic quantities such as Gibbs free energy (ΔG), the enthalpy (ΔH) and the entropy change of sorption (ΔS) were determined for natural, thermally and acid activated kaolinites. It was shown that the sorption processes were an endothermic reactions, controlled by physical mechanisms and spontaneously. Adsorption capacity of acid activated kaolinite for 3-methoxybenzaldehyde was higher compared to that of natural and thermally activated kaolinites at various temperatures. The adsorption and desorption rate constants (k a and k d ) were obtained separately by applying a geometric approach to the first order Langmuir model. This method provided good conformity between the K from Langmuir parameters and K geo (k a /k d ) from geometric approach

  18. Hydrophobicity study of kaolinite from La Unión, Antioquia

    Directory of Open Access Journals (Sweden)

    Liliana M. Usuga-Manco

    2015-07-01

    Full Text Available In this research three methodologies to convert the hydrophilic surface of kaolinite into a hydrophobic surface are proposed, this condition is required to recover this mineral by means of froth flotation. Taking into account the anisotropy, zeta potential and complex surface electrical properties of the kaolinite, three surface chemical treatments based on the interacting and absorption of anionic collectors onto the mineral surface, causing an increase in the contact angle and thus increased hydrophobicity of kaolinite were applied. The methodologies proposed were interactions of kaolinite particles with: sodium dodecyl sulfate solutions with concentration 1x10-3M, 1x10-4M, 1x10-5M; sodium dodecyl sulfate solutions 1x10-3M, 1x10-4M, 1x10-5M with further interaction with kerosene solutions 127000 ppm; and oleic acid solutions 1x10-3M, 1x10-4M, 1x10-5M, each one with a five minutes of interaction. The experimental results obtained by zeta potential and contact angle of the kaolinite before and after applying chemical treatments indicate that larger the chain length of the collector and its concentration, bigger the contact angle and so, more hydrophobic the surface (edge or face. In order to optimize, control and understand this solid-liquid interaction phenomenon is suggested to find out about the hydrophobization mechanism of kaolinite with oleic acid and its percentage of hydrophobization.

  19. Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments

    Science.gov (United States)

    Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

    2012-04-01

    Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25˚C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an

  20. Kaolinite: Defect defined material properties – A soft X-ray and first principles study of the band gap

    Energy Technology Data Exchange (ETDEWEB)

    Pietzsch, A., E-mail: annette.pietzsch@helmholtz-berlin.de [Institute for Methods and Instrumentation in Synchrotron Radiation Research G-ISRR, Helmholtz-Zentrum für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Nisar, J. [Pakistan Atomic Energy Commission (PAEC), P.O. Box 2151, Islamabad (Pakistan); Jämstorp, E. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Gråsjö, J. [Department of Pharmacy, Uppsala University, Box 580, 75123 Uppsala (Sweden); Århammar, C. [Coromant R& D, S-126 80 Stockholm (Sweden); Ahuja, R.; Rubensson, J.-E. [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden)

    2015-07-15

    Highlights: • The respective electronic structure of synthetic and natural kaolinite is compared. • The size of the band gap and thus many important material properties are defined by defect states in the band gap. • The oxygen-based defect states are identified and analyzed. • The band gap of kaolinite decreases significantly due to the forming of defects. - Abstract: By combining X-ray absorption spectroscopy and first principles calculations we have determined the electronic structure of synthetic and natural kaolinite as a model system for engineered and natural clay materials. We have analyzed defect states in the band gap and find that both natural and synthetic kaolinite contain defects where oxygen replaces hydrogen in one of the Al (0 0 1)-hydroxyl groups of the kaolinite clay sheets. The band gap of both synthetic and natural kaolinite is found to decrease by about 3.2 eV as this defect is formed.

  1. Kaolinite: Defect defined material properties – A soft X-ray and first principles study of the band gap

    International Nuclear Information System (INIS)

    Pietzsch, A.; Nisar, J.; Jämstorp, E.; Gråsjö, J.; Århammar, C.; Ahuja, R.; Rubensson, J.-E.

    2015-01-01

    Highlights: • The respective electronic structure of synthetic and natural kaolinite is compared. • The size of the band gap and thus many important material properties are defined by defect states in the band gap. • The oxygen-based defect states are identified and analyzed. • The band gap of kaolinite decreases significantly due to the forming of defects. - Abstract: By combining X-ray absorption spectroscopy and first principles calculations we have determined the electronic structure of synthetic and natural kaolinite as a model system for engineered and natural clay materials. We have analyzed defect states in the band gap and find that both natural and synthetic kaolinite contain defects where oxygen replaces hydrogen in one of the Al (0 0 1)-hydroxyl groups of the kaolinite clay sheets. The band gap of both synthetic and natural kaolinite is found to decrease by about 3.2 eV as this defect is formed

  2. A spectroscopic study of mechanochemically activated kaolinite with the aid of chemometrics.

    Science.gov (United States)

    Carmody, Onuma; Kristóf, János; Frost, Ray L; Makó, Eva; Kloprogge, J Theo; Kokot, Serge

    2005-07-01

    The study of kaolinite surfaces is of industrial importance. In this work we report the application of chemometrics to the study of modified kaolinite surfaces. DRIFT spectra of mechanochemically activated kaolinites (Kiralyhegy, Zettlitz, Szeg, and Birdwood) were analyzed using principal component analysis (PCA) and multicriteria decision making (MCDM) methods, PROMETHEE and GAIA. The clear discrimination of the Kiralyhegy spectral objects on the two PC scores plots (400-800 and 800-2030 cm(-1)) indicated the dominance of quartz. Importantly, no ordering of any spectral objects appeared to be related to grinding time in the PC plots of these spectral regions. Thus, neither the kaolinite nor the quartz, are systematically responsive to grinding time according to the spectral criteria investigated. The third spectral region (2600-3800 cm(-1)OH vibrations), showed apparent systematic ordering of the Kiralyhegy and, to a lesser extent, Zettlitz spectral objects with grinding time. This was attributed to the effect of the natural quartz on the delamination of kaolinite and the accompanying phenomena (i.e., formation of kaolinite spheres and water). With the MCDM methods, it was shown that useful information on the basis of chemical composition, physical properties and grinding time can be obtained. For example, the effects of the minor chemical components (e.g., MgO, K(2)O, etc.) indicated that the Birdwood kaolinite is arguably the most pure one analyzed. In another MCDM experiment, some support was obtained for the apparent trend with grinding time noted in the PC plot of the OH spectral region.

  3. Neptunium(V) sorption onto kaolinite in the absence and presence of CO2

    International Nuclear Information System (INIS)

    Amayri, S.; Reich, Ta.; Reich, T.

    2005-01-01

    Full text of publication follows: The adsorption of heavy metals on clay minerals such as kaolinite is an important process that affects the migration and retardation of neptunium and other actinides in the geosphere. The sorption of Np(V) onto the reference clay mineral kaolinite KGa-1b was investigated both by batch experiments and EXAFS measurements. The aim of our study was to combine macroscopic studies (batch experiments) with microscopic techniques (EXAFS) to study the Np(V) speciation at the kaolinite surface. The batch experiments were done under relevant environmental conditions with Np(V) concentrations of 10 -11 and 10 -12 mol/L. Sorption samples were prepared in 0.1 mol/L NaClO 4 , 4 g/L kaolinite, pH 6.0 to 10.5, presence and absence of ambient CO 2 , and 60-h equilibration. The sorption curves for 10 -11 and 10 -12 mol/L Np(V) obtained in the presence and absence of CO 2 , respectively, show that the adsorption edge occurs at pH 8.5. The uptake of Np(V) by kaolinite strongly increased above pH 7.0 and reached its sorption maximum (70 %) at pH 9.0. Above pH 9.0, the amount of Np(V) sorbed onto kaolinite decreased and reached ca. 30 % at pH 10.5 due to the formation of Np(V) carbonato species in the aqueous solution. In the CO 2 -free system, the sorption of Np(V) increased continuously with pH until the sorption maximum of 100 % was reached at pH 10.5. The same sorption behavior was found in batch experiments in the CO 2 equilibrated system with Np concentrations ranging from 1 μmol/L to 10 μmol/L. EXAFS experiments on some of these batch samples indicated the formation of Np(V) carbonato species at the kaolinite surface at pH 9.0 where the uptake of Np(V) by kaolinite reaches its maximum [1]. [1] T. Reich, S. Amayri, Ta. Reich, J. Drebert, A. Jermolajev, P. Thoerle, N. Trautmann, C. Hennig, S. Sachs, Feasibility of EXAFS experiments at the Np L-edge to investigate neptunium sorption on kaolinite, Institut fuer Kernchemie, Universitaet Mainz, Annual

  4. In situ neutron diffraction investigation on the phase transformation sequence of kaolinite and halloysite to mullite

    Energy Technology Data Exchange (ETDEWEB)

    Tezuka, Nobuo [Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, WA 6845 (Australia); Low, It-Meng [Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, WA 6845 (Australia)]. E-mail: J.Low@curtin.edu.au; Davies, Ian J. [Department of Mechanical Engineering, Curtin University of Technology, GPO Box U1987, Perth, WA 6845 (Australia); Prior, Michael [Bragg Institute, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Studer, Andrew [Bragg Institute, ANSTO, PMB 1, Menai, NSW 2234 (Australia)

    2006-11-15

    'Kaolin' is a major raw material for the fabrication of conventional ceramics. In this work the authors have investigated the thermal phase transformation of mullite from two different types of kaolin (kaolinite and halloysite), with or without alumina matrix constraint, during heating up to 1500 deg. C and then cooling using in situ neutron diffraction. Mullitization was initiated upon heating to 1200 deg. C for all specimens and followed spinel formation at 1100 deg. C. Above this temperature, however, evolution of the main phases, i.e., mullite, cristobalite and corundum, was influenced by the presence of impurities, initial type of silica, and alumina constraint. The relative amount of mullite was largest for the pure kaolinite specimen, particularly during heating, and this was attributed to the presence of a glassy phase. However, kaolinite with alumina suppressed the crystallization of cristobalite from the glassy phase upon cooling due to a reaction between alumina and amorphous silica, consequently resulting in an amount of mullite as for the pure kaolinite specimen (approximately 65 wt%). Halloysite was less active in terms of mullitization due to the lower level of initial impurities and greater amount of cristobalite, particularly for the alumina-constrained specimen. However, the final amount of mullite derived from the pure halloysite specimen was similar to that as from the kaolinite specimen.

  5. In situ neutron diffraction investigation on the phase transformation sequence of kaolinite and halloysite to mullite

    International Nuclear Information System (INIS)

    Tezuka, Nobuo; Low, It-Meng; Davies, Ian J.; Prior, Michael; Studer, Andrew

    2006-01-01

    'Kaolin' is a major raw material for the fabrication of conventional ceramics. In this work the authors have investigated the thermal phase transformation of mullite from two different types of kaolin (kaolinite and halloysite), with or without alumina matrix constraint, during heating up to 1500 deg. C and then cooling using in situ neutron diffraction. Mullitization was initiated upon heating to 1200 deg. C for all specimens and followed spinel formation at 1100 deg. C. Above this temperature, however, evolution of the main phases, i.e., mullite, cristobalite and corundum, was influenced by the presence of impurities, initial type of silica, and alumina constraint. The relative amount of mullite was largest for the pure kaolinite specimen, particularly during heating, and this was attributed to the presence of a glassy phase. However, kaolinite with alumina suppressed the crystallization of cristobalite from the glassy phase upon cooling due to a reaction between alumina and amorphous silica, consequently resulting in an amount of mullite as for the pure kaolinite specimen (approximately 65 wt%). Halloysite was less active in terms of mullitization due to the lower level of initial impurities and greater amount of cristobalite, particularly for the alumina-constrained specimen. However, the final amount of mullite derived from the pure halloysite specimen was similar to that as from the kaolinite specimen

  6. A role for subducted super-hydrated kaolinite in Earth’s deep water cycle

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae; Liu, Zhenxian; Liermann, Hanns-Peter; Cynn, Hyunchae; Vogt, Thomas; Kao, Chi-Chang; Mao, Ho-Kwang

    2017-11-20

    Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in a cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.

  7. A role for subducted super-hydrated kaolinite in Earth's deep water cycle

    Science.gov (United States)

    Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae; Liu, Zhenxian; Liermann, Hanns-Peter; Cynn, Hyunchae; Vogt, Thomas; Kao, Chi-Chang; Mao, Ho-Kwang

    2017-12-01

    Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in a cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.

  8. Removal of Pb(II) from aqueous solution using modified and unmodified kaolinite clay

    International Nuclear Information System (INIS)

    Jiang Mingqin; Wang Qingping; Jin Xiaoying; Chen Zuliang

    2009-01-01

    Modified kaolinite clay with 25% (w/w) aluminium sulphate and unmodified kaolin were investigated as adsorbents to remove Pb(II) from aqueous solution. The results show that amount of Pb(II) adsorbed onto modified kaolin (20 mg/g) was more than 4.5-fold than that adsorbed onto unmodified kaolin (4.2 mg/g) under the optimized condition. In addition, the linear Langmuir and Freundlich models were used to describe equilibrium isotherm. It is observed that the data from both adsorbents fitted well to the Langmuir isotherm. The kinetic adsorption of modified and unmodified kaolinite clay fitted well to the pseudo-second-order model. Furthermore, both modified and unmodified kaolinite clay were characterized by X-ray diffraction, Fourier transform infrared (FT-IR) and scanning electron microscope (SEM). Finally, both modified and unmodified kaolinite clay were used to remove metal ions from real wastewater, and results show that higher amount of Pb(II) (the concentration reduced from 178 to 27.5 mg/L) and other metal ions were removed by modified kaolinite clay compared with using unmodified adsorbent (the concentration reduced from 178 to 168 mg/L).

  9. Recovery of kaolinite from tailings of Zonouz kaolin-washing plant by flotation-flocculation method

    Directory of Open Access Journals (Sweden)

    Kianoush Barani

    2018-04-01

    Full Text Available The traditional processing of kaolin is achieved by dispersion of the mined ore and classification by multistage hydrocyclone plants. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back into the quarry. In this research, recovery of kaolinite from tailings of Zonouz kaolin washing plant, which is located in Iran was investigated by flotation and flotation- flocculation. Flotation experiments show that the flotation of kaolinite from the tailings is better in an acidic than in an alkaline medium containing cationic collectors. Flotation under acidic condition causes problems such as equipment corrosion at industrial scale. As a result, the cationic flotation of kaolinite is enhanced by addition of polyacrylamide as a flocculant. The results showed flocculation by polyacrylamide improved flotation of kaolinite within a range of pH. With 300 g/t dodecylamine, 500 g/t aluminum chloride, 50 g/t pine oil (frother, 15 g/t polyacrylamide, at pH = 7 and without de-slimming a product has 37.19% Al2O3, 54.19% SiO2 and 34.43% mass recovery was archived. Keywords: Kaolinite, Flotation, Flocculation, Cetylpyridinium chloride, Dodecylamine, Aluminum chloride, Polyacrylamide

  10. Adsorption and thermodynamic studies of Cu(II) and Zn(II) on organofunctionalized-kaolinite

    International Nuclear Information System (INIS)

    Guerra, Denis Lima; Airoldi, Claudio; Sousa, Kaline S. de

    2008-01-01

    Kaolinite-bearing clay samples from Perus, Sao Paulo state, Brazil, were used for chemical modification process with dimethyl sulfoxide and organofunctionalized with the silyating agent (RO) 3 Si(CH 2 ) 3 NH(CH 2 ) 2 NH 2 in the present study. The resulting material and natural kaolinite were subjected adsorpion process with Cu(II) and Zn(II) from aqueous solution at pH 6.0 and controlated temperature of 298 K. The Langmuir adsorption isotherm model has been applied to fit the experimental data. The results showed that the chemical modification process increases the basal spacing of the natural kaolinite from 0.711 to 0.955 nm. The energetic effects caused by Cu(II) and Zn(II) interactions were determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant

  11. Preparation and characterization of photoactive composite kaolinite/TiO2

    International Nuclear Information System (INIS)

    Mamulova Kutlakova, K.; Tokarsky, J.; Kovar, P.; Vojteskova, S.; Kovarova, A.; Smetana, B.; Kukutschova, J.; Capkova, P.; Matejka, V.

    2011-01-01

    Preparation of nanocomposite kaolinite/TiO 2 , using hydrolysis of titanyl sulfate in the presence of kaolin was addressed. A variable (kaolin)/(titanyl sulfate) ratio has been used in order to achieve the desired TiO 2 content in prepared nanocomposites. Calcination of the composites at 600 deg, C led to the transformation of the kaolinite to metakaolinite and to origination of metakaolinite/TiO 2 composites. The prepared samples were investigated using X-ray fluorescence spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry and diffuse reflectance spectroscopy in the UV-VIS region. Structural ordering of TiO 2 on the kaolinite particle surface was modeled using empirical force field atomistic simulations in the Material Studio modeling environment. Photodegradation activity of the composites prepared was evaluated by the discoloration of Acid Orange 7 aqueous solution.

  12. Kaolinite as an in situ dosimeter for past radionuclide migration at the Earth's surface

    International Nuclear Information System (INIS)

    Allard, T.; Muller, J.-P.

    1998-01-01

    The origin of 3 types of point defects (A-, Aminutes or feet- and B-centers) in kaolinite, due to natural irradiation and detected by electron paramagnetic resonance spectroscopy (EPR), has been demonstrated by artificial irradiation. The potential use of tracing the dynamics of the transfer of radionuclides through A-centers (i.e. the most stable centers) was qualitatively tested on different low-temperature alteration systems, some associated with U-concentrations. This paper proposes a quantitative approach to the reconstruction of the past migration of radionuclides by dosimetry of A-centers. With this aim in mind, the efficiency of α- and γ-radiations to produce A-centers was determined by experimental irradiation. Parameters extracted from A-center growth curves, together with their relationship with a parameter describing the degree of order of kaolinite, permitted (i) a definition to be made of the dose range in which a given kaolinite could be used as a dosimeter and (ii) the quantitative derivation of U-concentration from the cumulative dose (paleodose) of kaolinites. This was achieved by a formalism that accounted for the contribution of natural radiosources to the production of A-centers. The formalism was applied to the Nopal I U-deposit (Chihuhua, Mexico), considered as a natural analogue of a high level nuclear waste repository. Irrespective of the scenario considered, in terms of kaolinite age and of degree of isotopic disequilibrium in the system, A-center dosimetry permitted the determination of past occurrences of U which were several orders of magnitude higher than the present-day measured U-concentrations. Furthermore, this approach also provided evidence for several previous episodes of U-migration. EPR spectroscopy is thus a unique tool for the quantitative, indirect assessment of past radionuclide migration in the geosphere and kaolinite is a reliable in-situ dosimeter. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights

  13. Surface complexation modeling of Cu(II adsorption on mixtures of hydrous ferric oxide and kaolinite

    Directory of Open Access Journals (Sweden)

    Schaller Melinda S

    2008-09-01

    Full Text Available Abstract Background The application of surface complexation models (SCMs to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids. Results Cu adsorption was measured on pure hydrous ferric oxide (HFO, pure kaolinite (from two sources and in systems containing mixtures of HFO and kaolinite over a wide range of pH, ionic strength, sorbate/sorbent ratios and, for the mixed solid systems, using a range of kaolinite/HFO ratios. Cu adsorption data measured for the HFO and kaolinite systems was used to derive diffuse layer surface complexation models (DLMs describing Cu adsorption. Cu adsorption on HFO is reasonably well described using a 1-site or 2-site DLM. Adsorption of Cu on kaolinite could be described using a simple 1-site DLM with formation of a monodentate Cu complex on a variable charge surface site. However, for consistency with models derived for weaker sorbing cations, a 2-site DLM with a variable charge and a permanent charge site was also developed. Conclusion Component additivity predictions of speciation in mixed mineral systems based on DLM parameters derived for the pure mineral systems were in good agreement with measured data. Discrepancies between the model predictions and measured data were similar to those observed for the calibrated pure mineral systems. The results suggest that quantifying specific interactions between HFO and kaolinite in speciation models may not be necessary. However, before the component additivity approach can be applied to natural sediments and soils, the effects of aging must be further studied and methods must be developed to estimate reactive surface areas of solid constituents in natural samples.

  14. Adsorption of pesticides onto quartz, calcite, kaolinite, and α-alumina

    DEFF Research Database (Denmark)

    Clausen, Liselotte; Fabricius, Ida Lykke; Madsen, L.

    2001-01-01

    adsorption characteristics of selected pesticides. Investigated mineral phases included quartz, calcite, kaolinite, and alpha -alumina. Selected pesticides comprised atrazine (6-chloro-N-2-ethyl-N-4-isopropyl-1,3,5-triazine-2,4-diamine isoproturon [3-(4-isopropyl-phenyl)-1,1-dimethylurea)], mecoprop [(RS)-2...... due to formation of Ca-pesticide-surface complexes. Adsorption of the uncharged pesticides (atrazine and isoproturon) was detected only on kaolinite. The lack of adsorption on alpha -alumina indicates that the uncharged pesticides have a greater affinity for the silanol surface sites (= SiOH) than...

  15. Flotation of kaolinite from tailings of kaolin-washing plants by cationic collectors

    Directory of Open Access Journals (Sweden)

    Barani Kianoush

    2016-01-01

    Full Text Available Traditional processing of kaolin is achieved by dispersion of the mined ore and classification by means of multistage hydrocyclones. The inefficiencies inherent to cyclones produce a middling product that is commonly disposed back to the quarry. In this research recovery of kaolinite from tailings of the Zonoupz kaolin washing plant, which is located in Iran, was investigated by cationic flotation. Flotation experiments showed that flotation of kaolinite from tailings was much better in an acidic than in an alkaline medium containing cationic collectors.

  16. Effect of water on methane adsorption on the kaolinite (0 0 1) surface based on molecular simulations

    Science.gov (United States)

    Zhang, Bin; Kang, Jianting; Kang, Tianhe

    2018-05-01

    CH4 adsorption isotherms of kaolinite with moisture contents ranging from 0 to 5 wt% water, the effects of water on maximum adsorption capacity, kaolinite swelling, and radial distribution function were modelled by the implementing combined Monte Carlo (MC) and molecular dynamics (MD) simulations at 293.15 K (20 °C) and a pressure range of 1-20 MPa. The simulation results showed that the absolute adsorption of CH4 on both dry and moist kaolinite followed a Langmuir isotherm within the simulated pressure range, and both the adsorption capacity and the rate of CH4 adsorption decreased with the water content increases. The adsorption isosteric heats of CH4 on kaolinite decreased linearly with increasing water content, indicating that at higher water contents, the interaction energy between the CH4 and kaolinite was weaker. The interaction between kaolinite and water dominates and was the main contributing factor to kaolinite clay swelling. Water molecules were preferentially adsorbed onto oxygen and hydrogen atoms in kaolinite, while methane showed a tendency to be adsorbed only onto oxygen. The simulation results of our study provide the quantitative analysis of effect of water on CH4 adsorption capacity, adsorption rate, and interaction energy from a microscopic perspective. We hope that our study will contribute to the development of strategies for the further exploration of coal bed methane and shale gas.

  17. Kaolinite: a natural radiations dosemeter. Application to past radioelement migrations tracing in the geosphere

    International Nuclear Information System (INIS)

    Allard, Thierry

    1994-01-01

    The efficiency of the processes regulating the mobility of the radioelements in the geosphere can be assessed by the study of past migrations of uranium. For that geochemical purpose, it can be used mineral tracers like kaolinite, which records past contacts with radioelements as radiation-induced defects. Three radiation-induced centers had been identified in kaolinite by means of electron paramagnetic resonance, i.e. the A-, A'- and B-centers, and interpreted as hole centers located on oxygen atoms of the structure. The A-center is stable at the scale of geological periods. Consequently, it could be directly used to measure paleo-doses, that are related to the past occurrence of radioelements. This works states the potentialities of kaolinite as a dosimeter for the study or past migrations of uranium in the geosphere: - Experimental irradiations: we studied the effects of the main natural radiations (alpha and gamma) within a dose range consistent with that occurring in geo-systems at the Earth surface. We simulated these radiation effects by irradiating natural reference kaolinites with He + ions provided by the ARAMIS particle accelerator (Orsay) and a 60 Co source (CENG, Grenoble), respectively. We took into account the natural variability of kaolinites in terms of crystalline disorder and chemical (Fe 3+ ) or mineralogical (illite, smectite) impurities. It is confirmed that the sensitivity of the radiation-induced centers decreases in the order B>A>A'. The dosimetry curve of the A center can be described with an exponential function constrained by two parameters (the concentration at saturation and the efficiency coefficient) which are correlated. These dosimetry parameters are also correlated with the crystalline order of the kaolinites, which suggests the possibility to assess them by a measurement of crystalline disorder (with EPR). Moreover, the alpha irradiations of illite and of smectite evidenced radiation centers, which can disturb the EPR

  18. Modification of kaolinite surfaces through mechanochemical activation with quartz: A diffuse reflectance infrared fourier transform and chemometrics study.

    Science.gov (United States)

    Carmody, Onuma; Frost, Ray L; Kristóf, János; Kokot, Serge; Kloprogge, J Theo; Makó, Eva

    2006-12-01

    Studies of kaolinite surfaces are of industrial importance. One useful method for studying the changes in kaolinite surface properties is to apply chemometric analyses to the kaolinite surface infrared spectra. A comparison is made between the mechanochemical activation of Kiralyhegy kaolinites with significant amounts of natural quartz and the mechanochemical activation of Zettlitz kaolinite with added quartz. Diffuse reflectance infrared Fourier transform (DRIFT) spectra were analyzed using principal component analysis (PCA) and multi-criteria decision making (MCDM) methods, the preference ranking organization method for enrichment evaluations (PROMETHEE) and geometrical analysis for interactive assistance (GAIA). The clear discrimination of the Kiralyhegy spectral objects on the two PC scores plots (400-800 and 800-2030 cm(-1)) indicated the dominance of quartz. Importantly, no ordering of any spectral objects appeared to be related to grinding time in the PC plots of these spectral regions. Thus, neither the kaolinite nor the quartz are systematically responsive to grinding time according to the spectral criteria investigated. The third spectral region (2600-3800 cm(-1), OH vibrations), showed apparent systematic ordering of the Kiralyhegy and, to a lesser extent, Zettlitz spectral objects with grinding time. This was attributed to the effect of the natural quartz on the delamination of kaolinite and the accompanying phenomena (i.e., formation of kaolinite spheres and water). The mechanochemical activation of kaolinite and quartz, through dry grinding, results in changes to the surface structure. Different grinding times were adopted to study the rate of destruction of the kaolinite and quartz structures. This relationship (i.e., grinding time) was classified using PROMETHEE and GAIA methodology.

  19. Polyaniline/TiO{sub 2}/kaolinite: The composite material with high electrical anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Tokarský, Jonáš, E-mail: jonas.tokarsky@vsb.cz [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava (Czech Republic); Neuwirthová, Lucie; Peikertová, Pavlína [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava (Czech Republic); Kulhánková, Lenka [Faculty of Metallurgy and Materials Engineering, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava (Czech Republic); Mamulová Kutláková, Kateřina; Matějka, Vlastimil [Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava (Czech Republic); Čapková, Pavla [Faculty of Science, J.E. Purkyně University, České mládeže 8, 400 96 Ústí nad Labem (Czech Republic)

    2014-07-01

    Kaolinite–TiO{sub 2} nanocomposite matrix (KATI) coated with polyaniline (PANI) layer has been prepared in powder form and pressed into tablets. The conductivity was studied in dependence on (1) wt.% of TiO{sub 2} in KATI matrix and (2) thermal pre-treatment of KATI matrix. The anisotropy factor α, i.e. the ratio of in-plane conductivity and conductivity in the direction perpendicular to the tablet plane, was found to be very high for PANI/KATI tablet (α is of the order of 10{sup 3}–10{sup 4}) in comparison with pure PANI tablet (α is of the order of 10{sup 2}). Structure has been studied using Raman spectroscopy, X-ray diffraction analysis, scanning electron microscopy and molecular modeling. The possibility of using the tablets as a load sensors have been tested and tablets pressed from composites containing calcined KATI seem to be promising material for this purpose. - Graphical abstract: Tablets pressed from powder form of polyaniline/TiO{sub 2}/kaolinite composites exhibit very high electrical anisotropy and were found to be suitable as load sensors. - Highlights: • Kaolinite/TiO{sub 2}/polyaniline composites exhibit very high electrical anisotropy. • Presence of TiO{sub 2} helps polyaniline to fully cover the kaolinite particles. • Tablets pressed from these composites can be used as load sensors. • Calcination of kaolinite/TiO{sub 2} matrix improves the sensing properties.

  20. Effect of kaolinite and Ca-montmorillonite on the alleviation of soil water repellency

    Czech Academy of Sciences Publication Activity Database

    Dlapa, P.; Doerr, S. H.; Lichner, Ľ.; Šír, Miloslav; Tesař, Miroslav

    2004-01-01

    Roč. 50, č. 8 (2004), s. 358-363 ISSN 0370-663X R&D Projects: GA AV ČR IAA3042301; GA AV ČR IBS2060104 Keywords : water repellency * kaolinite * Ca-montmorillonite Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.379, year: 2004

  1. Effect of composition and physical properties of. natural kaolinitic clays on their strong acid weathering rates

    Czech Academy of Sciences Publication Activity Database

    Hradil, David; Hostomský, Jiří

    2002-01-01

    Roč. 49, 1-2 (2002), s. 171-181 ISSN 0341-8162 R&D Projects: GA ČR GA203/98/P203 Institutional research plan: CEZ:AV0Z4032918 Keywords : kaolinite * illite * dissolution Subject RIV: CA - Inorganic Chemistry Impact factor: 1.035, year: 2002

  2. Microstructure, Interaction Mechanisms, and Stability of Binary Systems Containing Goethite and Kaolinite

    NARCIS (Netherlands)

    Wei, S.Y.; Tan, W.F.; Zhao, W.; Yu, Y.T.; Liu, F.; Koopal, L.K.

    2012-01-01

    Goethite and kaolinite are ubiquitous in natural environments. In soils they are often cemented together as a binary association, which has a significant influence on the structure and properties of soils. In this study, the mineralogy (using X-ray diffraction [XRD], thermal analyses, and infrared

  3. Mean residence time of soil organic matter associated with kaolinite and smectite

    NARCIS (Netherlands)

    Wattel-Koekkoek, E.J.W.; Buurman, P.; Plicht, van der J.; Wattel, J.T.; Breemen, van N.

    2003-01-01

    To gain insight into the effect of clay mineralogy on the turnover of organic matter, we analysed the C-14 activity of soil organic matter associated with clay in soils dominated by kaolinite and smectite in natural savanna systems in seven countries. Assuming that carbon inputs and outputs are in

  4. Mean residence time of soil organic matter associated with kaolinite and smectite

    NARCIS (Netherlands)

    Wattel-Koekkoek, E.J.W.; Buurman, P.; Plicht, J. van der; Wattel, E.; Breemen, N. van

    To gain insight into the effect of clay mineralogy on the turnover of organic matter, we analysed the C-14 activity of soil organic matter associated with clay in soils dominated by kaolinite and smectite in natural savanna systems in seven countries. Assuming that carbon inputs and outputs are in

  5. The Influence of Temperature on Kaolinite Fired Clay- Cement Materials Used as Disposal of Radioactive Waste

    International Nuclear Information System (INIS)

    El-Dakroury, A.

    2008-01-01

    The decay of encapsulated radioactive nuclides may cause elevation of the temperature in the waste form. Cement has been used for immobilization of low and intermediated level radioactive waste. The unstable component of concrete is the ordinary Portland cement (OPC). This study aimed to investigate experimentally the change occurring in the compressive strength and physico- chemical properties of ordinary Portland cement (OPC) matrices in comparable with other matrices which (OPC) were partially substituted by 0, 10, 20 and 30% of thermally-activated kaolinite clay by weight (the kaolinite clay activated by firing at 750 degree C for 5 hr then quenched by tap water). If all matrices mentioned before, are being exposed to the treatment temperature were varied from 100 degree C to 600 degree C by increment of 100 degree C for period of 3 hr without any load. The phase composition was performed by mean of differential thermal analysis and X-R-D. The results show that the replacements of (OPC) by 20 wt % thermal-activated Kaolinite clay improve the compressive properties by 30 %. The results of this investigation cleared that the recrystallization and carbonation of Ca(OH) 2 ; they also show a deformation of C-H-S and C 4 Ah 13 phases, besides the matrices have more stable resistance at 600 degree C. Meanwhile, this new immobilization matrix 20 % by wt thermally activated Kaolinite - clay showed the lowest leaching rate of simulated radioactive waste of Sr or Cs compared to the ordinary Portland cement (OPC) matrix

  6. Polyaniline/TiO2/kaolinite: The composite material with high electrical anisotropy

    International Nuclear Information System (INIS)

    Tokarský, Jonáš; Neuwirthová, Lucie; Peikertová, Pavlína; Kulhánková, Lenka; Mamulová Kutláková, Kateřina; Matějka, Vlastimil; Čapková, Pavla

    2014-01-01

    Kaolinite–TiO 2 nanocomposite matrix (KATI) coated with polyaniline (PANI) layer has been prepared in powder form and pressed into tablets. The conductivity was studied in dependence on (1) wt.% of TiO 2 in KATI matrix and (2) thermal pre-treatment of KATI matrix. The anisotropy factor α, i.e. the ratio of in-plane conductivity and conductivity in the direction perpendicular to the tablet plane, was found to be very high for PANI/KATI tablet (α is of the order of 10 3 –10 4 ) in comparison with pure PANI tablet (α is of the order of 10 2 ). Structure has been studied using Raman spectroscopy, X-ray diffraction analysis, scanning electron microscopy and molecular modeling. The possibility of using the tablets as a load sensors have been tested and tablets pressed from composites containing calcined KATI seem to be promising material for this purpose. - Graphical abstract: Tablets pressed from powder form of polyaniline/TiO 2 /kaolinite composites exhibit very high electrical anisotropy and were found to be suitable as load sensors. - Highlights: • Kaolinite/TiO 2 /polyaniline composites exhibit very high electrical anisotropy. • Presence of TiO 2 helps polyaniline to fully cover the kaolinite particles. • Tablets pressed from these composites can be used as load sensors. • Calcination of kaolinite/TiO 2 matrix improves the sensing properties

  7. Theoretical investigation of lead vapor adsorption on kaolinite surfaces with DFT calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xinye [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China); Huang, Yaji, E-mail: heyyj@seu.edu.cn [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China); Pan, Zhigang [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); Wang, Yongxing; Liu, Changqi [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China)

    2015-09-15

    Highlights: • Al surface after dehydroxylation is active while Si surface is inert. • The active sites are the unsaturated Al atoms and O atoms losing H atom. • PbO is the most suitable species for adsorption. • Increasing the activities of Al atoms can enhance the performance of kaolinite. • Produce of amorphous silica is a potential path to enhance the performance of kaolinite. - Abstract: Kaolinite can be used as the in-furnace sorbent/additive to adsorb lead (Pb) vapor at high temperature. In this paper, the adsorptions of Pb atom, PbO molecule and PbCl{sub 2} molecule on kaolinie surfaces were investigated by density functional theory (DFT) calculation. Si surface is inert to Pb vapor adsorption while Al surfaces with dehydroxylation are active for the unsaturated Al atoms and the O atoms losing H atoms. The adsorption energy of PbO is much higher than that of Pb atom and PbCl{sub 2}. Considering the energy barriers, it is easy for PbO and PbCl{sub 2} to adsorb on Al surfaces but difficult to escape. The high energy barriers of de–HCl process cause the difficulties of PbCl{sub 2} to form PbO·Al{sub 2}O{sub 3}·2SiO{sub 2} with kaolinite. Considering the inertia of Si atoms and the activity of Al atoms after dehydroxylation, calcination, acid/alkali treatment and some other treatment aiming at amorphous silica producing and Al activity enhancement can be used as the modification measures to improve the performance of kaolinite as the in-furnace metal capture sorbent.

  8. Thorough Mastication Prior to Swallowing Increases Postprandial Satiety and the Thermic Effect of a Meal in Young Women.

    Science.gov (United States)

    Komai, Naho; Motokubota, Naoko; Suzuki, Maki; Hayashi, Ikuyo; Moritani, Toshio; Nagai, Narumi

    2016-01-01

    There is evidence to support that mastication may contribute to the prevention of weight gain via reduction of appetite sensations and subsequent energy intake. However, the metabolic effect of mastication after consumption of a daily meal, composed of the staple food (rice), soup, main and side dishes, is limited. Therefore, the effect of thorough mastication on greater satiety and the thermic effect of a meal (TEM) was investigated in young women. In study 1, energy expenditure (EE) derived from masticatory muscle activity for 20 min was measured while chewing hard, tasteless, non-caloric gum in seven subjects. In study 2, ten subjects consumed a solid meal performing 30 chews per mouthful (30 CPM), or swallowed the same, pureed meal without chewing (0 CPM) on two separate days, and postprandial EE, substrate oxidation, subjective appetite ratings and autonomic nervous system (ANS) activity for 3 h were examined. Both test meals were iso-caloric (2,510 kJ) and -weighted (884 g), and consumed in 20 min. From study 1, the EE of mastication itself for the 20 min was estimated to be 3.7±0.8 kJ. From study 2, significantly higher TEM (134.2±15.5 vs. 67.8±13.8 kJ/3 h, pmastication before swallowing increased postprandial satiety and the TEM in young women, suggesting such eating behavior may be useful for preventing obesity.

  9. Comparative EXAFS study of uranium(VI) and neptunium(V) sorption onto kaolinite

    International Nuclear Information System (INIS)

    Reich, T.; Amayri, S.; Reich, Ta.; Jermolajev, J.

    2005-01-01

    Full text of publication follows: We investigated the surface sorption process of U(VI) and Np(V) on kaolinite by extended X-ray absorption fine structure (EXAFS) spectroscopy in the 10 μM concentration range. Batch experiments with kaolinite in CO 2 -equilibrated systems showed that the adsorption edge of U(VI) occurs at pH 5.5, i.e., near the pH PZC of kaolinite. The adsorption edge of Np(V) occurs well above the pH PZC value at pH 8.5. This may indicate that the bonds between Np(V) and the surface functional groups of kaolinite are not as strong as in the case of U(VI). U(VI) and Np(V) have in common that the amount which is adsorbed decreases when the pH is increased beyond the absorption maximum. This behavior can be attributed to the formation of U(VI) and Np(V) carbonato complexes in the aqueous solutions. The aim of this comparative EXAFS study was to investigate the reason for the different affinities of U(VI) and Np(V) for kaolinite by measuring their local environments at the clay surface. Samples were prepared from 4 g/L kaolinite, 0.1 M NaClO 4 , pH 3.0 - 10.5, presence and absence of ambient CO 2 . The U L 3 - and Np L 2 -edge EXAFS spectra of the wet paste samples were measured at room temperature in fluorescence mode at the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility. The measured U-O and U-Al/Si distances indicate inner-sphere sorption of U(VI) on kaolinite. There was no evidence of uranium neighbors in the EXAFS spectra, suggesting that the adsorbed U(VI) complexes were predominantly monomeric. The average distance between uranium and its equatorial oxygen atoms, O eq , increased from 2.32 to 2.38 Angstrom in the presence of atmospheric CO 2 when the pH was increased from 5.0 to 8.5. In the CO 2 -free system, the U-O eq distance was independent from pH and equal to 2.32 Angstrom. The lengthening of the average U-O eq distance in the presence of carbonate (or bicarbonate) suggests the formation of ternary U

  10. Is our Universe typical?

    International Nuclear Information System (INIS)

    Gurzadyan, V.G.

    1988-01-01

    The problem of typicalness of the Universe - as a dynamical system possessing both regular and chaotic regions of positive measure of phase space, is raised and discussed. Two dynamical systems are considered: 1) The observed Universe as a hierarchy of systems of N graviting bodies; 2) (3+1)-manifold with matter evolving to Wheeler-DeWitt equation in superspace with Hawking boundary condition of compact metrics. It is shown that the observed Universe is typical. There is no unambiguous answer for the second system yet. If it is typical too then the same present state of the Universe could have been originated from an infinite number of different initial conditions the restoration of which is practically impossible at present. 35 refs.; 2 refs

  11. Preparation of Composite Hydrogel Based on Polyacrylamide and the Effect of Kaolinite on Its Properties in the Reservoir Conditions

    OpenAIRE

    Farhad Salimi; Mohsen Vafaie; Mehdi Razzaghi Kashani; Majid Rafipoor

    2013-01-01

    A gel composite (based on polyacrylamide and crosslinker Cr(III) acetate) was prepared by solvent method (distillate and water formation) and nanoclay particle (kaolinite). Using XRD tests, d001 was evaluated for kaolinite nanoparticles in gel composite. Kaolinite modification using dimethyl-sulfoxide led to increase interlamellar spacing from 7.21 to 10.82 o A. Based on the results obtained for samples prepared from unmodified clay besides the pure clay, there is a wide peak at 2θ = 8o; whic...

  12. Typical Complexity Numbers

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Typical Complexity Numbers. Say. 1000 tones,; 100 Users,; Transmission every 10 msec. Full Crosstalk cancellation would require. Full cancellation requires a matrix multiplication of order 100*100 for all the tones. 1000*100*100*100 operations every second for the ...

  13. Comparison of electrodialytic removal of Cu from spiked kaolinite, spiked soil and industrially polluted soil

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Lepkova, Katarina; Kubal, Martin

    2006-01-01

    Electrokinetic remediation methods for removal of heavy metals from polluted soils have been subjected for quite intense research during the past years since these methods are well suitable for fine-grained soils where other remediation methods fail. Electrodialytic remediation is an electrokinetic...... remediation method which is based on applying an electric DC field and the use of ion exchange membranes that ensures the main transport of heavy metals to be out of the pollutes soil. An experimental investigation was made with electrodialytic removal of Cu from spiked kaolinite, spiked soil and industrially...... polluted soil under the same operational conditions (constant current density 0.2 mA/cm2 and duration 28 days). The results of the present paper show that caution must be taken when generalising results obtained in spiked kaolinite to remediation of industrially polluted soils, as it was shown...

  14. The growth of multi-walled carbon nanotubes on natural clay minerals (kaolinite, nontronite and sepiolite)

    International Nuclear Information System (INIS)

    Pastorková, K.; Jesenák, K.; Kadlečíková, M.; Breza, J.; Kolmačka, M.; Čaplovičová, M.; Lazišťan, F.; Michalka, M.

    2012-01-01

    The suitability of clay minerals - kaolinite, nontronite and sepiolite - is studied for synthesis of nanocomposites based on carbon nanotubes. Particles of iron were used as catalysts. Prior to synthesis, kaolinite and sepiolite were doped by the catalytically active metal, whereas in the case of nontronite the presence was used of this metal in the matrix of this mineral. Synthesis of CNTs was performed by hot filament chemical vapor deposition method. The produced nanocomposites were examined by transmission and scanning electron microscopies and energy dispersive X-ray spectroscopy. The experiment verified the potential of the three microcrystalline phyllosilicates for the growth of carbon nanotubes. Under the same technology conditions, the type of catalyst carrier affects the morphology and structure of the nanotube product markedly.

  15. Adsorption behavior of strontium on binary mineral mixtures of Montmorillonite and Kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Bascetin, Elvan [Cekmece Nuclear Research and Training Center, P.K.1 34149, Atatuerk Airport, Istanbul (Turkey); Atun, Guelten [Engineering Faculty, Chemistry Department, Istanbul University, 34850 Avcilar, Istanbul (Turkey)]. E-mail: gultena@istanbul.edu.tr

    2006-08-15

    The adsorption behavior of kaolinite and montmorillonite minerals and their mixtures in respect of Sr ion were studied by means of a batch method using {sup 90}Sr as a radio tracer. The effect of several parameters such as temperature, pH, Sr concentration and supporting electrolyte were investigated. Experimentally measured distribution coefficients showed a good agreement to within 98.5-99.7% with theoretically calculated values. The values of adsorption capacity of adsorbents and mean adsorption energy of adsorption were calculated by fitting the adsorption data to Dubinin-Radushkevich isotherm. The adsorption capacity of clay mixtures decreased as kaolinite fractions increased. The mean adsorption energy values of 8.0-9.5 kJ mol{sup -1} showed that adsorption was governed by ion exchange. The Freundlich parameters were used to characterize a site distribution function for binary exchange between Sr and Na.

  16. Adsorption behavior of strontium on binary mineral mixtures of Montmorillonite and Kaolinite

    International Nuclear Information System (INIS)

    Bascetin, Elvan; Atun, Guelten

    2006-01-01

    The adsorption behavior of kaolinite and montmorillonite minerals and their mixtures in respect of Sr ion were studied by means of a batch method using 90 Sr as a radio tracer. The effect of several parameters such as temperature, pH, Sr concentration and supporting electrolyte were investigated. Experimentally measured distribution coefficients showed a good agreement to within 98.5-99.7% with theoretically calculated values. The values of adsorption capacity of adsorbents and mean adsorption energy of adsorption were calculated by fitting the adsorption data to Dubinin-Radushkevich isotherm. The adsorption capacity of clay mixtures decreased as kaolinite fractions increased. The mean adsorption energy values of 8.0-9.5 kJ mol -1 showed that adsorption was governed by ion exchange. The Freundlich parameters were used to characterize a site distribution function for binary exchange between Sr and Na

  17. Typicality and reasoning fallacies.

    Science.gov (United States)

    Shafir, E B; Smith, E E; Osherson, D N

    1990-05-01

    The work of Tversky and Kahneman on intuitive probability judgment leads to the following prediction: The judged probability that an instance belongs to a category is an increasing function of the typicality of the instance in the category. To test this prediction, subjects in Experiment 1 read a description of a person (e.g., "Linda is 31, bright, ... outspoken") followed by a category. Some subjects rated how typical the person was of the category, while others rated the probability that the person belonged to that category. For categories like bank teller and feminist bank teller: (1) subjects rated the person as more typical of the conjunctive category (a conjunction effect); (2) subjects rated it more probable that the person belonged to the conjunctive category (a conjunction fallacy); and (3) the magnitudes of the conjunction effect and fallacy were highly correlated. Experiment 2 documents an inclusion fallacy, wherein subjects judge, for example, "All bank tellers are conservative" to be more probable than "All feminist bank tellers are conservative." In Experiment 3, results parallel to those of Experiment 1 were obtained with respect to the inclusion fallacy.

  18. Typicals/Típicos

    Directory of Open Access Journals (Sweden)

    Silvia Vélez

    2004-01-01

    Full Text Available Typicals is a series of 12 colour photographs digitally created from photojournalistic images from Colombia combined with "typical" craft textiles and text from guest writers. Typicals was first exhibited as photographs 50cm x 75cm in size, each with their own magnifying glass, at the Contemporary Art Space at Gorman House in Canberra, Australia, in 2000. It was then exhibited in "Feedback: Art Social Consciousness and Resistance" at Monash University Museum of Art in Melbourne, Australia, from March to May 2003. From May to June 2003 it was exhibited at the Museo de Arte de la Universidad Nacional de Colombia Santa Fé Bogotá, Colombia. In its current manifestation the artwork has been adapted from the catalogue of the museum exhibitions. It is broken up into eight pieces corresponding to the contributions of the writers. The introduction by Sylvia Vélez is the PDF file accessible via a link below this abstract. The other seven PDF files are accessible via the 'Supplementary Files' section to the left of your screen. Please note that these files are around 4 megabytes each, so it may be difficult to access them from a dial-up connection.

  19. Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Stockmann, Madlen [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO{sub 4} by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

  20. Effects of brief milling and acid treatment on two ordered and disordered kaolinite structures

    Czech Academy of Sciences Publication Activity Database

    Valášková, M.; Barabaszová, K.; Hundáková, M.; Ritz, M.; Plevová, Eva

    2011-01-01

    Roč. 54, č. 1 (2011), s. 70-76 ISSN 0169-1317 R&D Projects: GA ČR GA105/08/1398 Grant - others:GA ČR(CZ) GA205/09/0352 Institutional research plan: CEZ:AV0Z30860518 Keywords : kaolinite * milling * hydrochloric acid Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.474, year: 2011 http://www.sciencedirect.com/science/article/pii/S0169131711002675

  1. Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

    International Nuclear Information System (INIS)

    Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna; Stockmann, Madlen

    2017-01-01

    In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO_4 by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

  2. Kaolinite adsorption-regeneration system for dyestuff treatment by Fenton based processes.

    Science.gov (United States)

    Rosales, Emilio; Anasie, Delia; Pazos, Marta; Lazar, Iuliana; Sanromán, M Angeles

    2018-05-01

    The regeneration and reuse of adsorbents is a subject of interest nowadays in order to reduce the pollution and the wastes generated in the adsorption wastewater treatment. In this work, the regeneration of the spent kaolinite by different advanced oxidation processes (Fenton, electro-Fenton and electrokinetic-Fenton) was evaluated. Initially, it was confirmed the ability of a low cost clayey material, kaolinite, for the adsorption of model dye such as Rhodamine B showing Freundlich isotherm fitting. Then, the regeneration and consequent degradation of the pollutant in the adsorbent by Fenton based processes was carried out. The role of different parameters affecting the regeneration process (H 2 O 2 :Fe 2+ ratio, liquid:solid ratio) were evaluated. Working at 100:1 H 2 O 2 :Fe 2+ ratio and 30min near complete dye removal (around 97%) from kaolinite was obtained by Fenton treatment. After that, a two-stage treatment for adsorption-regeneration was evaluated during five treatment cycles demonstrating its viability for regeneration of the adsorbent through dye degradation. Based on the successful application of Fenton technique, the improvement of the treatment by electro-Fenton and electrokinetic-Fenton were studied for different solid:liquid ratios achieving satisfactory regeneration values. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Testing the stability of magnetic iron oxides/kaolinite nanocomposite under various pH conditions

    Science.gov (United States)

    Tokarčíková, Michaela; Tokarský, Jonáš; Kutláková, Kateřina Mamulová; Seidlerová, Jana

    2017-09-01

    Magnetically modified clays containing iron oxides nanoparticles (FexOy NPs) are low-cost and environmentally harmless materials suitable for sorption of pollutants from wastewaters. Stability of this smart material was evaluated both experimentally and theoretically using molecular modelling. Original kaolinite and prepared FexOy/kaolinite nanocomposite were characterized using X-ray fluorescence spectroscopy, X-ray powder diffraction, infrared spectroscopy, and transmission electron microscopy, and the stability was studied using leaching tests performed according to the European technical standard EN 12457-2 in deionized water and extraction agents with varying pH (2, 4, 9, and 11). The influence of pH on amount of FexOy NPs released from the composite and amount of the basic elements released from the kaolinite structure was studied using inductively coupled plasma atomic emission spectroscopy. All experiments proved that the magnetic properties of the nanocomposite will not change even after leaching in extraction agents with various pH.

  4. Chemial Bond and Stability of Adsorption of[Au(AsS3)]2- on the Surface of Kaolinite

    Institute of Scientific and Technical Information of China (English)

    MIN Xin-min; CHEN Yun; HONG Han-lie

    2004-01-01

    Density function theory and discrete variation method (DFT-DVM) were used to study the adsorption of [Au(AsS3 ) ]2- on the surface of kaolinite. The correlation among structure, chemical bond and stability was discussed. Several models were selected with [ Au( AsS3 ) ]2- in different directions and sites. The resultsshow that the models with gold on the edge of kaolinite basal layer contain pincerlike bond among gold and severaloxygen atoms and form strong Au - O covalent bond, so these models are more stable than those with gold aboveor under the layer. The models with gold near to [ AlO2(OH)4 ] octahedra are more stable than those with goldnear to the vacancy without aluminium. These two stable tendencies in kaolinite- [ Au( AsS3 ) ]2- are stronger thanthat in kaolinite-Au systems. The interaction between [ Au( AsS3 ) ]2- and kaolinite is stronger than that betweengold and kaolinite, and this interaction is strong enough to form the surface complexes.

  5. Probing adsorption of polyacrylamide-based polymers on anisotropic Basal planes of kaolinite using quartz crystal microbalance.

    Science.gov (United States)

    Alagha, Lana; Wang, Shengqun; Yan, Lujie; Xu, Zhenghe; Masliyah, Jacob

    2013-03-26

    Quartz crystal microbalance with dissipation (QCM-D) was applied to investigate the adsorption characteristics of polyacrylamide-based polymers (PAMs) on anisotropic basal planes of kaolinite. Kaolinite basal planes were differentiated by depositing kaolinite nanoparticles (KNPs) on silica and alumina sensors in solutions of controlled pH values. Adsorption of an in-house synthesized organic-inorganic Al(OH)3-PAM (Al-PAM) as an example of cationic hybrid PAM and a commercially available partially hydrolyzed polyacrylamide (MF1011) as an example of anionic PAM was studied. Cationic Al-PAM was found to adsorb irreversibly and preferentially on tetrahedral silica basal planes of kaolinite. In contrast, anionic MF1011 adsorbed strongly on aluminum-hydroxy basal planes, while its adsorption on tetrahedral silica basal planes was weak and reversible. Adsorption study revealed that both electrostatic attraction and hydrogen-bonding mechanisms contribute to adsorption of PAMs on kaolinite. The adsorbed Al-PAM layer was able to release trapped water overtime and became more compact, while MF1011 film became more dissipative as backbones stretched out from kaolinite surface with minimal overlapping. Experimental results obtained from this study provide clear insights into the phenomenon that governs flocculation-based solid-liquid separation processes using multicomponent flocculants of anionic and cationic nature.

  6. Effect of polycarboxylate ether comb-type polymer on viscosity and interfacial properties of kaolinite clay suspensions.

    Science.gov (United States)

    Zhang, Ling; Lu, Qingye; Xu, Zhenghe; Liu, Qingxia; Zeng, Hongbo

    2012-07-15

    The interactions between kaolinite clay particles and a comb-type polymer (polycarboxylate ether or PCE), so-called PCE super-plasticizer, were investigated through viscosity and surface forces measurements by a rheometer and a Surface Forces Apparatus (SFA). The addition of PCE shows a strong impact on the viscosity of concentrated kaolinite suspensions in alkaline solutions (pH=8.3) but a weak effect under acidic conditions (pH=3.4). In acidic solutions, the high viscosity measured is attributed to the strong electrostatic interaction between negatively charged basal planes and positively charged edge surfaces of clay particles. Under the alkaline condition, the suspension viscosity was found to first increase significantly and then decrease with increasing PCE dosages. The results from surface forces measurement show that PCE molecules at low dosages can bridge the kaolinite particles in the concentrated suspensions via hydrogen bonding, leading to the formation of a kaolinite-PCE "network" and hence an increased suspension viscosity. At high PCE dosages, clay particles are fully covered by PCE molecules, leading to a more dispersed kaolinite suspensions and hence lower suspension viscosity due to steric repulsion between the adsorbed PCE molecules. The insights derived from measuring viscosity and interfacial properties of kaolinite suspensions containing varying amount of comb-type super-plasticizer PCE at different pH provide the foundation for many engineering applications and optimizing industrial processes. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Planning model for hydraulic and thermic generation systems expansion under uncertainly conditions and financial restrictions; Modelo de planejamento da expansao de sistemas hidrotermicos sob incertezas e restricoes financeiras

    Energy Technology Data Exchange (ETDEWEB)

    Gorenstin, B.G.; Costa, J.P. da [CEPEL, Rio de Janeiro, RJ (Brazil); Pereira, M.V.F.; Campodonico, N.M.

    1993-12-31

    This issue presents a methodology for planning the systems expansion of hydraulic and thermic power generation associated considering several uncertainly factors, such as: demand growing, fuel costs, delays on the work construction, financial restrictions, etc. The solution focus is based on stock optimize techniques, decision analysis. This work is being developed by the Brazilian Electrical Centre (ELETROBRAS) and rely on the Energy Latin-American Organization (OLADE), Development Inter-American Bank (BID), World Bank (BIRD) and International Energy Agency (IAEA) support. An example case with Costa Rica system is also discussed 19 refs., 4 figs., 2 tabs.

  8. A Typical Synergy

    Science.gov (United States)

    van Noort, Thomas; Achten, Peter; Plasmeijer, Rinus

    We present a typical synergy between dynamic types (dynamics) and generalised algebraic datatypes (GADTs). The former provides a clean approach to integrating dynamic typing in a statically typed language. It allows values to be wrapped together with their type in a uniform package, deferring type unification until run time using a pattern match annotated with the desired type. The latter allows for the explicit specification of constructor types, as to enforce their structural validity. In contrast to ADTs, GADTs are heterogeneous structures since each constructor type is implicitly universally quantified. Unfortunately, pattern matching only enforces structural validity and does not provide instantiation information on polymorphic types. Consequently, functions that manipulate such values, such as a type-safe update function, are cumbersome due to boilerplate type representation administration. In this paper we focus on improving such functions by providing a new GADT annotation via a natural synergy with dynamics. We formally define the semantics of the annotation and touch on novel other applications of this technique such as type dispatching and enforcing type equality invariants on GADT values.

  9. Thermically tuned nematic guide

    Science.gov (United States)

    Corella-Madueño, Adalberto; Reyes, Juan Adrián

    2006-06-01

    We consider a cylindrical fiber with a liquid crystal core satisfying homeotropic weak anchoring boundary conditions. We find the different textures of the nematic inside the cylinder obtained by changing the temperature. We calculate exactly the spatial distribution of the transverse magnetic modes in the guide as a function of temperature of the system by using a numerical scheme.

  10. Fe(0)-Kaolinite (KGA2) interactions at 90° C under anoxic conditions

    International Nuclear Information System (INIS)

    Rivard, C.; Pelletier, M.; Montarges-Pelletier, E.; Michot, L.; Villieras, F.; Abdelmoula, M.; Karunakaran, C.; Ventelon, D.; Michau, N.

    2010-01-01

    Document available in extended abstract form only. Because of the use of steel containers for geological deposit of nuclear waste, it is of prime importance to understand the interaction mechanisms between the geological matrix, Callovo-Oxfordian argillite, and the steel container. In order to evidence the individual role of each different clay phase entering in the mineralogy of the Callovo-Oxfordian argillite, the iron-clay interactions were studied by the use of reference clays. The Georgia Kaolinite (KGa2) supplied by the Clay Mineral Society was selected to represent kaolinite minerals; as it has been extensively characterized in our laboratory. To reproduce the repository conditions, raw kaolinite was put in contact with powder metallic iron with a weight ratio fixed at 1/3 and a solid/liquid ratio of 1/20. Batch experiments were carried out in anoxic conditions at 90 deg. C in the presence of background electrolyte (NaCl 0.02 M.L -1 , CaCl 2 0.04 M.L -1 ) in Parr reactors for durations of one, three or nine months. Similar experiments without iron were carried out to show up the influence of iron on mineralogical transformations in such conditions. After, one, three or nine months, solid and liquid phases were separated by centrifugation and characterized by classical techniques combining chemical analyses, X-ray diffraction, Fourier Transform Infrared spectroscopy, scanning and transmission electron microscopy, XPS and Moessbauer analyses. Supplementary observation tools, based on the use of synchrotron radiation were used to reinforce the information about iron localisation and its status in individualized clay particles (Scanning Transmission X-ray Microscopy (STXM) and Micro-Xray Absorption Spectroscopy (μ-XAS)). Without iron, kaolinite KGa2 remains unchanged, from a mineralogical point of view, even after nine months in suspension. With iron, first results from one month experiments showed a decrease of pristine metallic iron as well as the apparition

  11. Uranium(VI) retention on quartz and kaolinite. Experiments and modelling

    International Nuclear Information System (INIS)

    Mignot, G.

    2001-01-01

    The behaviour of uranium in the geosphere is an important issue for safety performance assessment of nuclear waste repositories, or in the context of contaminated sites due to mining activity related to nuclear field. Under aerobic conditions, the fate of uranium is mainly governed by the ability of minerals to sorb U(VI) aqueous species. Hence, a thorough understanding of U(VI) sorption processes on minerals is required to provide a valuable prediction of U(VI) migration in the environment. In this study, we performed sorption/desorption experiments of U(VI) on quartz and kaolinite, for systems favouring the formation in solution (i) of UO 2 2+ and monomeric hydrolysis products or (ii) of di-/tri-meric uranyl aqueous species, and / or U(VI)-colloids or UO 2 (OH) 2 precipitates, or (iii) of uranyl-carbonate complexes. Particular attention was paid to determine the surface characteristics of the solids and their modification due to dissolution/precipitation processes during experiments. A double layer surface complexation model was applied to our experimental data in order to derive surface complexation equilibria and intrinsic constants which allow a valuable description of U(VI) retention over a wide range of pH, ionic strength, initial concentration of uranium [0.1-10μM] and solid - solution equilibration time. U(VI) sorption on quartz was successfully modeled by using two sets of adsorption equilibria, assuming (i) the formation of the surface complexes SiOUO 2 + , SiOUO 2 OH and SiO(UO 2 ) 3 (OH) 5 , or (ii) the formation of the mono-dentate complex SiO(UO 2 ) 3 (OH) 5 and of the bidentate complex (SiO) 2 UO 2 . Assumptions on the density of each type of surface sites of kaolinite and on their acid-base properties were made from potentiometric titrations of kaolinite suspensions. We proposed on such a basis a set of surface complexation equilibria which accounts for U(VI) uptake on kaolinite over a wide range of chemical conditions, with aluminol edge sites as

  12. Surface characteristics of kaolinite and other selected 2-layer silicate minerals

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.D.; Nalaskowski, J.; Abdul, B.; Du, H. [Utah Univ., Salt Lake City, UT (United States). Dept. of Metallurgical Engineering

    2007-10-15

    The wetting of mineral phases by bitumens plays an important role in efficient bitumen recovery. In this study, molecular dynamics simulations were used to investigate the electrokinetic behaviour and interfacial water features of 2-layer silicate minerals. The study compared the planar structures of antigorite and kaolinite with equivalent tubular structures of halloysite and chrysolite. Equivalency of pH dependency of zeta potential was determined using electrophoretic mobility measurements. The atomic mismatch between tetrahydral and octahydral sheets in a bilayer was examined in order to determine electrokinetic behaviour. Results of the study indicated that the silica tetrahydral surface was not wetted by water, but by structural imperfections. Polarity reversal within a tetrahedral octahedral layer and an out-of-order layer within the stack were then considered to explain both the wetting characteristics and electrokinetic behaviour. It was concluded that further research is needed to explain why the hexagonal rings structure for the silica tetrahydral face of kaolinite is wetted by water. 55 refs., 2 tabs., 12 figs.

  13. Effects of Organic Acids on Adsorption of Cadmium onto Kaolinite, Goethite, and Bayerite

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Effects of organic acids (oxalic, acetic, and citric) on adsorption characteristics of Cadmium (Cd) on soil clay minerals(kaolinite, goethite, and bayerite) were studied under different concentrations and different pH values. Although the types of organic acids and minerals were different, the effects of the organic acids on the adsorption of Cd on the minerals were similar, i.e., the amount of adsorbed Cd with an initial solution pH of 5.0 and initial Cd concentration of 35 mg L-1increased with increasing concentration of the organic acid in solution at lower concentrations, and decreased at higher concentrations. The percentage of Cd adsorbed on the minerals in the presence of the organic acids increased considerably with increasing pH of the solution. Meanwhile, different Cd adsorption in the presence of the organic acids, due to different properties on both organic acids and clay minerals, on kaolinite, goethite, or bayerite for different pHs or organic acid concentrations was found.

  14. Obtention of the cation exchange capacity of a natural kaolinite with radioactive tracers

    International Nuclear Information System (INIS)

    Uribe I, A.; Badillo A, V.E.; Monroy G, F.

    2005-01-01

    One of the more used techniques for the elimination of the heavy metals present in water systems is to use adsorbent mineral phases like zeolites and clays, among others. The clays are able to exchange easily the fixed ions in the external surface of its crystals or well the ions present in the interlaminar spaces of the structures, for other existent ones in the encircling aqueous solutions for that the Cation exchange capacity (CIC) is defined as the sum of all the cations exchange that a mineral can possess independent to the physicochemical conditions. The CIC is equal to the measure of the total of negative charges of the mineral by mass of the solid (meq/g). In this investigation work, the value of the CIC equal to 2.5 meq/100 g is obtained, of a natural kaolinite from the State of Hidalgo studying the retention of the sodium in the kaolinite with the aid of the radioactive isotope 24 Na and of the selective electrodes technique, making vary the pH value. So is experimentally demonstrated that the CIC is an intrinsic property of the mineral independent of the pH value of the solution and of the charges origin. (Author)

  15. Effect of Cosolutes on the Sorption of Phenanthrene onto Mineral Surface of River Sediments and Kaolinite

    Directory of Open Access Journals (Sweden)

    Yinghong Wu

    2014-01-01

    Full Text Available Sorption of phenanthrene onto the natural sediment with low organic carbon content (OC%, organic-free sediment, and kaolinite was investigated through isotherm experiments. Effects of cosolutes (pyrene, 4-n-nonyphenol (NP, and humic acid (HA on phenanthrene sorption were also studied by comparing apparent solid-water distribution coefficients (Kdapp of phenanthrene. Two addition sequences, including “cosolute added prior to phenanthrene” and “cosolute and phenanthrene added simultaneously,” were adopted. The Freundlich model fits phenanthrene sorption on all 3 sorbents well. The sorption coefficients on these sorbents were similar, suggesting that mineral surface plays an important role in the sorption of hydrophobic organic contaminants on low OC% sediments. Cosolutes could affect phenanthrene sorption on the sorbents, which depended on their properties, concentrations, and addition sequences. Pyrene inhibited phenanthrene sorption. Sorbed NP inhibited phenanthrene sorption at low levels and promoted sorption at high levels. Similar to NP, effect of HA on phenanthrene sorption onto the natural sediment depended on its concentrations, whereas, for the organic-free sediment and kaolinite, preloading of HA at high levels led to an enhancement in phenanthrene Kdapp while no obvious effect was observed at low HA levels; dissolved HA could inhibit phenanthrene sorption on the two sorbents.

  16. Effect of polyvinylpyrrolidone and sodium lauroyl isethionate on kaolinite suspension in an aqueous phase.

    Science.gov (United States)

    Kwan, Chang-Chin; Chu, Wen-Hweu; Shimabayashi, Saburo

    2006-08-01

    Suspension of concentrated kaolinite (20 g/30 ml-medium) in the presence of polyvinylpyrrolidone (PVP) and sodium lauroyl isethionate (SLI) was allowed to evaluate its degree of dispersion based on their rheological studies. Flow curves at low shear rate, measured by means of cone-plate method, showed a non-Newtonian flow. Plastic viscosity and Bingham yield value were derived from the flow curves. Relative viscosity, effective volume fraction and void fraction of secondary particle were also obtained. Results of dispersity and fluidity of the suspension were explained. PVP acted as a flocculant at a concentration lower than 0.1% but as a dispersant at a higher concentration. The presence of SLI could decrease both the Bingham yield value and suspension viscosity. Cooperative and competitive effects of PVP and SLI were found. Results indicated that SLI enhanced the degree of dispersion of kaolinite when PVP was less than 0.1%. The suspension, however, showed a maximum flocculation (i.e., aggregation) at 4 mM SLI when the concentration of PVP was higher than 0.1%.

  17. Crystallization of aqueous ammonium sulfate particles internally mixed with soot and kaolinite: crystallization relative humidities and nucleation rates.

    Science.gov (United States)

    Pant, Atul; Parsons, Matthew T; Bertram, Allan K

    2006-07-20

    Using optical microscopy, we investigated the crystallization of aqueous ammonium sulfate droplets containing soot and kaolinite, as well as the crystallization of aqueous ammonium sulfate droplets free of solid material. Our results show that soot did not influence the crystallization RH of aqueous ammonium sulfate particles under our experimental conditions. In contrast, kaolinite increased the crystallization RH of the aqueous ammonium sulfate droplets by approximately 10%. In addition, our results show that the crystallization RH of aqueous ammonium sulfate droplets free of solid material does not depend strongly on particle size. This is consistent with conclusions made previously in the literature, based on comparisons of results from different laboratories. From the crystallization results we determined the homogeneous nucleation rates of crystalline ammonium sulfate in aqueous ammonium sulfate droplets and the heterogeneous nucleation rates of crystalline ammonium sulfate in aqueous ammonium sulfate particles containing kaolinite. Using classical nucleation theory and our experimental data, we determined that the interfacial tension between an ammonium sulfate critical nucleus and an aqueous ammonium sulfate solution is 0.064 +/- 0.003 J m(-2) (in agreement with our previous measurements), and the contact angle between an ammonium sulfate critical nucleus and a kaolinite surface is 59 +/- 2 degrees. On the basis of our results, we argue that soot will not influence the crystallization RH of aqueous ammonium sulfate droplets in the atmosphere, but kaolinite can significantly modify the crystallization RH of atmospheric ammonium sulfate droplets. As an example, the CRH50 (the relative humidity at which 50% of the droplets crystallize) ranges from about 41 to 51% RH when the diameter of the kaolinite inclusion ranges from 0.1 to 5 microm. For comparison, the CRH50 of aqueous ammonium sulfate droplets (0.5 microm diameter) free of solid material is

  18. Dating Amazonian laterites through the novel geochronometers kaolinite and iron oxides

    Science.gov (United States)

    Allard, Thierry; Bressan Riffel, Silvana; Gautheron, Cécile; Fernandes Soares, Bruna; Pinna-Jamme, Rosella; Morin, Guillaume

    2016-04-01

    Soils on Earth's surface are in constant interaction with climate. As a matter of fact, soils cannot only produce greenhouse effect gases, such as NO2 and CH4, but also behave as sinks for CO2, especially by silicate weathering. Major processes of silicate weathering are known and exhibit climatic zonation at the global scale. Laterites are particularly relevant because they are ancient and deeply weathered soils of major significance. They occupy 30 % of the continental surface and can keep records of past climates and landscape modifications (paleosurface) through specific mineral markers. These formations reach several tens of meters and are mainly composed of kaolinite, iron and aluminium oxides as well as relicts of parent minerals such as quartz and ancillary minerals. Once the major processes of laterite formation are known, their age will allow a growth of researches, owing to the implementation of various chronometers. Moreover, it is fundamental to date laterites in order to improve our understanding of soil formation related to paleoclimates, and to build predictive models of their evolution. In this study, we focus on comparing kaolinite ages with the still unknown ages of lateritic duricrusts from the central Amazon region (Brazil), where strong weathering processes were developed from the early Tertiary, after the Andean uplift. The central Amazon region displays flat areas and dissected plateaus (100-180 m a.s.l.) sustained by weathered clastic sedimentary rocks and latosols. The region contains horizons of duricrusts, relatively continuous layers of Fe-cuirasses, stratified lateritic profiles, and kaolin deposits. Here we employed two methods to date ubiquitous secondary minerals of laterite, which are consistent with geological time-scale. The corresponding geochronometers are the following: (i) radiation-induced defects in kaolinite (trapped in duricrusts) analysed by electron paramagnetic resonance spectroscopy (EPR) (Balan et al., 2005), and (ii

  19. Monitoring and assessment of thermical comfort in hygrothermically moderate offices and laboratories; Monitoraggio e valutazione del comfort termico negli ambienti di lavoro termoigrometricamente moderati

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, A. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dip. Ambiente

    1998-12-31

    This study reports the results of the micro climatic measurements carried out in some ENEA work environments. The work conditions in the surveyed areas, have been evaluated following welfare indexes or thermical comfort: PMV= Predicted Mean Vote (ISO recommendation 7730); PPD= Predicted Percentage of Dissatisfied (ISO recommendation 7730). [Italiano] In questo studio sono riportati i risultati delle misure microclimatiche eseguite in alcuni ambienti di lavoro dei centri ENEA di Bologna. Le condizioni di lavoro (delle zone che sono state sottoposte ad indagine) sono state valutate mediante i seguenti indici di benessere o `comfort` termico: Voto Medio Previsto (PMV= Predicted Mean Vote) - raccomandazione ISO 7730; Percentuale Prevista di Insoddisfatti (PPD= Predicted Percentage of Dissatisfied) - raccomandazione ISO 7730.

  20. Monitoring and assessment of thermical comfort in hygrothermically moderate offices and laboratories; Monitoraggio e valutazione del comfort termico negli ambienti di lavoro termoigrometricamente moderati

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, A [ENEA, Centro Ricerche ` Ezio Clementel` , Bologna (Italy). Dip. Ambiente

    1999-12-31

    This study reports the results of the micro climatic measurements carried out in some ENEA work environments. The work conditions in the surveyed areas, have been evaluated following welfare indexes or thermical comfort: PMV= Predicted Mean Vote (ISO recommendation 7730); PPD= Predicted Percentage of Dissatisfied (ISO recommendation 7730). [Italiano] In questo studio sono riportati i risultati delle misure microclimatiche eseguite in alcuni ambienti di lavoro dei centri ENEA di Bologna. Le condizioni di lavoro (delle zone che sono state sottoposte ad indagine) sono state valutate mediante i seguenti indici di benessere o `comfort` termico: Voto Medio Previsto (PMV= Predicted Mean Vote) - raccomandazione ISO 7730; Percentuale Prevista di Insoddisfatti (PPD= Predicted Percentage of Dissatisfied) - raccomandazione ISO 7730.

  1. The immersion freezing behavior of size-segregated soot and kaolinite particles

    Science.gov (United States)

    Hartmann, S.; Augustin, S.; Clauss, T.; Niedermeier, D.; Raddatz, M.; Wex, H.; Shaw, R. A.; Stratmann, F.

    2011-12-01

    Heterogeneous ice nucleation plays a crucial role for ice formation in mixed-phase and cirrus clouds and has an important impact on precipitation formation, global radiation balances, and therefore Earth's climate (Cantrell and Heymsfield, 2005). Mineral dust and soot particles are found to be a major component of ice crystal residues (e.g., Pratt et al., 2009) so these substances are potential sources of atmospheric ice nuclei (IN). Experimental studies investigating the immersion freezing behavior of size-segregated soot and kaolinite particles conducted at the Leipzig Aerosol Cloud Interaction Simulator (LACIS) are presented. In our measurements only one aerosol particle is immersed in an air suspended water droplet which can trigger ice nucleation. The method facilitates very precise examinations with respect to temperature, ice nucleation time and ice nucleus size. Considering laboratory studies, the picture of the IN ability of soot particles is quite heterogeneous. Our studies show that submicron flame, spark soot particles and optionally coated with sulfuric acid to simulate chemically aging do not act as IN at temperatures higher than homogeneous freezing taking place. Therefore soot particles might not be an important source of IN for immersion freezing in the atmosphere. In contrast, kaolinite being representative for natural mineral dust with a well known composition and structure is found to be very active in forming ice for all freezing modes (e.g., Mason and Maybank, 1958). Analyzing the immersion freezing behavior of different sized kaolinite particles (300, 500 and 700 nm in diameter) the size effect was clearly observed, i.e. the ice fraction (number of frozen droplets per total number) scales with particle surface, i.e. the larger the ice nucleus surface the higher the ice fraction. The slope of the logarithm of the ice fraction as function of temperature is similar for all particle sizes investigated and fits very well with the results of L

  2. Characterization of Sr2+ uptake on natural minerals of kaolinite and magnesite using XRPD, SEM/EDS, XPS, and DRIFT

    International Nuclear Information System (INIS)

    Shahwan, T.; Erten, H.N.

    2005-01-01

    The sorption behavior of Sr 2+ ions on natural minerals rich in kaolinite and magnesite was studied using SEM/EDS, XPS, XRPD, AAS/AES and DRIFT techniques. Quantitative analysis of the XPS data shows that magnesite is more effective in Sr 2+ uptake than kaolinite. DRIFT spectra and XRPD patterns indicate that the structures of both minerals were not affected upon Sr 2+ sorption. Intercalation of DMSO in kaolinite lamellae aiming at increasing the interlayer space did not significantly enhance the sorption capacity of the clay towards Sr 2+ probably due to the lack of a negative charge on the accessible sites. EDS mapping indicated that while the sorbed Sr is equally distributed on surface of natural kaolinite, it was associated - to a larger extent - with the regions richer in Mg in the case of natural magnesite. Comparing the uptake mechanisms of natural magnesite with that of pure MgCO 3 , it was seen that while natural magnesite sorbed Sr 2+ mainly through an ion exchange type mechanism, the formation of SrCO 3 coprecipitate was detected on the surface of the MgCO 3 at higher loadings. (orig.)

  3. Kinetics and Thermodynamics of Sorption of 4-Nitrophenol on Activated Kaolinitic Clay and Jatropha Curcas Activated Carbon from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Samsudeen Olanrewaju Azeez

    2016-06-01

    Full Text Available Adsorption behaviour of 4-nitrophenol (4-NP on activated kaolinitic clay and Jatropha curcas activated carbon was investigated. The kaolinitic clay and Jatropha curcas were activated with 1 M HNO3 and 0.5 M NaOH respectively and were characterized by XRF, XRD, BET, SEM and FTIR techniques. The effects of processing parameters, such as initial 4-NP concentration, temperature, pH, contact time and adsorbent dosage on the adsorption process were investigated. The results obtained showed that Jatropha curcas activated carbon exhibited higher performance than activated kaolinitic clay for the removal of 4-nitrophenol from aqueous solution. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models were used to describe the adsorption isotherms. The adsorption data were best fitted with Freundlich model. The experimental data of the two adsorbate-adsorbent systems fitted very well with the pseudo-second order kinetic model with r2 values of 0.999 respectively. Adsorption thermodynamic parameters were also estimated. The results revealed that the adsorption of 4-nitrophenol onto both adsorbents were exothermic processes and spontaneous for Jatropha curcas activated carbon but non spontaneous for activated kaolinitic clay.

  4. Kinetics and thermodynamics of sorption of 4-nitrophenol on activated kaolinitic clay and jatropha curcas activated carbon from aqueous solution

    International Nuclear Information System (INIS)

    Azeez, S.O.; Adekola, F.A.

    2016-01-01

    Adsorption behaviour of 4-nitrophenol (4-NP) on activated kaolinitic clay and Jatropha curcas activated carbon was investigated. The kaolinitic clay and Jatropha curcas were activated with 1 M HNO/sub 3/ and 0.5 M NaOH respectively and were characterized by XRF, XRD, BET, SEM and FTIR techniques. The effects of processing parameters, such as initial 4-NP concentration, temperature, pH, contact time and adsorbent dosage on the adsorption process were investigated. The results obtained showed that Jatropha curcas activated carbon exhibited higher performance than activated kaolinitic clay for the removal of 4-nitrophenol from aqueous solution. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models were used to describe the adsorption isotherms. The adsorption data were best fitted with Freundlich model. The experimental data of the two adsorbate-adsorbent systems fitted very well with the pseudosecond order kinetic model with r2 values of 0.999 respectively. Adsorption thermodynamic parameters were also estimated. The results revealed that the adsorption of 4-nitrophenol onto both adsorbents were exothermic processes and spontaneous for Jatropha curcas activated carbon but non spontaneous for activated kaolinitic clay. (author)

  5. Sorption of triclosan onto activated carbon, kaolinite and montmorillonite: effects of pH, ionic strength, and humic acid.

    Science.gov (United States)

    Behera, Shishir Kumar; Oh, Seok-Young; Park, Hung-Suck

    2010-07-15

    Sorption of triclosan on three sorbents, viz., activated carbon, kaolinite and montmorillonite was studied as a function of pH, ionic strength and humic acid (HA) concentration through controlled batch experiments. Triclosan sorption was found to be higher in the acidic pH range, as varying pH showed significant influence on the surface charge of the sorbents and degree of ionization of the sorbate. Sorption capacity of the sorbents increased with an increase in the ionic strength of solution. At low pH (pH 3), the overall increase in triclosan sorption was 1.2, approximately 4 and 3.5 times, respectively for activated carbon, kaolinite and montmorillonite when ionic strength was increased from 1x10(-3) to 5x10(-1) M. Triclosan sorption onto activated carbon decreased from 31.4 to 10.6 mg g(-1) by increasing the HA concentration to 200 mg C L(-1). However, during sorption onto kaolinite and montmorillonite, the effect of HA was very complex probably due to (i) hydrophobicity (log K(ow)=4.76) of triclosan; and (ii) complexation of HA with triclosan. Though triclosan sorption onto activated carbon is higher, the potential of kaolinite and montmorillonite in controlling the transport of triclosan in subsurface environment can still be appreciable. 2010 Elsevier B.V. All rights reserved.

  6. U(VI) sorption on kaolinite. Effects of pH, U(VI) concentration and oxyanions

    International Nuclear Information System (INIS)

    Liang Gao; Ziqian Yang; Keliang Shi; Xuefeng Wang; Zhijun Guo; Wangsuo Wu

    2010-01-01

    U(VI) sorption on kaolinite was studied as functions of contact time, pH, U(VI) concentration, solid-to-liquid ratio (m/V) by using a batch experimental method. The effects of sulfate and phosphate on U(VI) sorption were also investigated. It was found that the sorption kinetics of U(VI) can be described by a pseudo-second-order model. Potentiometric titrations at variable ionic strengths indicated that the titration curves of kaolinite were not sensitive to ionic strength, and that the pH of the zero net proton charge (pH PZNPC ) was at 6.9. The sorption of U(VI) on kaolinite increased with pH up to 6.5 and reached a plateau at pH >6.5. The presence of phosphate strongly increased U(VI) sorption especially at pH <5.5, which may be due to formation of ternary surface complexes involving phosphate. In contrast, the presence of sulfate did not cause any apparent effect on U(VI) sorption. A double layer model was used to interpret both results of potentiometric titrations and U(VI) sorption on kaolinite. (author)

  7. Structure of kaolinite and influence of stacking faults: reconciling theory and experiment using inelastic neutron scattering analysis.

    Science.gov (United States)

    White, Claire E; Kearley, Gordon J; Provis, John L; Riley, Daniel P

    2013-05-21

    The structure of kaolinite at the atomic level, including the effect of stacking faults, is investigated using inelastic neutron scattering (INS) spectroscopy and density functional theory (DFT) calculations. The vibrational dynamics of the standard crystal structure of kaolinite, calculated using DFT (VASP) with normal mode analysis, gives good agreement with the experimental INS data except for distinct discrepancies, especially for the low frequency modes (200-400 cm(-1)). By generating several types of stacking faults (shifts in the a,b plane for one kaolinite layer relative to the adjacent layer), it is seen that these low frequency modes are affected, specifically through the emergence of longer hydrogen bonds (O-H⋯O) in one of the models corresponding to a stacking fault of -0.3151a - 0.3151b. The small residual disagreement between observed and calculated INS is assigned to quantum effects (which are not taken into account in the DFT calculations), in the form of translational tunneling of the proton in the hydrogen bonds, which lead to a softening of the low frequency modes. DFT-based molecular dynamics simulations show that anharmonicity does not play an important role in the structural dynamics of kaolinite.

  8. Analysis and characterization of kaolinitic clay Rio Grande do Norte for use in refractory

    International Nuclear Information System (INIS)

    Medeiros, A.L.; Souza Junior, C.F.; Silva, C.L. Mendes da

    2011-01-01

    This work aims to characterize clays from the State of Rio Grande do Norte for use in the manufacture of refractory bricks. Initially, we analyzed the X-ray fluorescence and X-ray diffraction on samples of clay to obtain the components of the starting materials and their microstructures. The test samples were fabricated by uniaxial pressure of 20 MPa, and then were sintered between 1000 ° C and 1200 ° C, with a landing sintering for 1 hour. Tests including thermal shrinkage, water absorption and apparent porosity. Initial results of the analysis indicate the presence of clay minerals kaolinite, montmorillonite and muscovite, as well group minerals of quartz, dolomite, calcite and calcium silicate in the samples tested. (author)

  9. Adsorption of barium on kaolinite, illite and montmorillonite at various ionic strengths

    International Nuclear Information System (INIS)

    Atun, G.; Bascetin, E.

    2003-01-01

    The sorption behaviour of Ba 2+ in three different clay minerals from various regions of Turkey has been investigated by means of a tracer technique using 133 Ba in batch experiments. Sorption of Ba 2+ on montmorillonite, kaolinite and illite has been studied in mixed solutions of BaCl 2 and NaCl at ionic strengths ranging from 1 x 10 -3 M to 1 x 10 -1 M. The L-shape exchange isotherms for Ba 2+ -Na + systems are well defined by a Langmuir type equation. The exchange capacity of Ba 2+ ions for all three clay minerals increased with decreasing ionic strength. The adsorption data were fitted to a Freundlich isotherm and empirical Freundlich parameters enabled to the generation of a site distribution function. The selectivity coefficients were nearly constant at low Ba loading and decreased as loading increased. This behavior was an indication of an ion exchange process between Ba 2+ and Na + ions

  10. Adsorption of some heavy metals on sulphate and phosphate modified kaolinite clay

    International Nuclear Information System (INIS)

    Adebowale, K.O.; Unuabonah, I.E.; Olu-Owolabi, B.I.

    2003-12-01

    Kaolinite clay, in bright white lumps collected from from Ubulu-Ukwu, Delta State, Nigeria, was modified with 200μ.ml -1 of phosphate and sulphate anion and thereafter used to adsorb some heavy metals viz. lead (Pb), Cadmium (Cd), Zinc (Zn) and Copper (Cu) from aqueous solution of the metals. The metal ions showed the greatest affinity for the P-modified (P-mod) sorbents. The order of adsorption of P-mod follows the order: P-mod Pb > P-mod Cu > P-mod Zn > P-mod Cd . Desorption studies showed that the P-modified sorbents exhibited a very strong ability to specifically adsorb lead, copper and zinc and are therefore poorly desorbed. All the metals were easily desorbed from the unmodified sorbent. The potential of the modified sorbents are enumerated. (author)

  11. Physical attributes of kaolinitic and oxidic oxisols resulting from different usage systems

    Directory of Open Access Journals (Sweden)

    José Frederico Centurion

    2004-09-01

    Full Text Available The objective of this study was to assess the physical attributes of a kaolinitic oxisol, medium texture (Haplustox and an oxidic oxisol, clayey (Eutrustox under different usage systems, localized in the region of Jaboticabal, SP, Brazil. The usage systems were sugarcane, cotton and forest. Parameters such as soil bulk density, total porosity, macro and microporosity at the depths of 0.0-0.1; 0.1-0.2; 0.2-0.3, and 0.3-0.4 m were evaluated. Haplustox showed greater bulk density and smaller total porosity, macro and microporosity. The usage increased the bulk density in 0.0-0.3 m depth, with greater effects on the kaolinitic oxisol, mainly in 0.1-0.2 m depth in the areas cultivated with sugarcane.A mineralogia da fração argila e os sistemas de uso exercem fundamental importância na estrutura do solo. Assim, objetivou-se avaliar atributos físicos de um Latossolo Vermelho Distrófico, caulinítico (LVd, e, de um Latossolo Vermelho Eutroférrico, oxídico (LVef, sob diferentes sistemas de uso, localizados no município de Jaboticabal (SP, Brasil. Os sistemas de uso foram: cana-de-açúcar; algodão e mata. Foram avaliadas a densidade do solo, porosidade total, macro e microporosidade, nas profundidades de 0,0-0,1, 0,1-0,2, 0,2-0,3, 0,3-0,4 m. O Latossolo caulinítico (LVd apresentou maior densidade do solo e menor porosidade total, macro e microporosidade. O uso aumentou a densidade do solo na profundidade de 0,0-0,3 m, com efeitos maiores no Latossolo caulinítico, principalmente na profundidade de 0,1-0,2 m na área cultivada com cana-de-açúcar.

  12. Adsorption kinetics of maxilon yellow 4GL and maxilon red GRL dyes on kaolinite

    International Nuclear Information System (INIS)

    Dogan, Mehmet; Karaoglu, M. Hamdi; Alkan, Mahir

    2009-01-01

    Kaolinite, a low-costly material, is the most abundant phyllosilicate mineral in highly weathered soils. In this work, the adsorption kinetics of maxilon yellow 4GL (MY 4GL) and maxilon red GRL (MR GRL) dyes on kaolinite from aqueous solutions was investigated using the parameters such as contact time, stirring speed, initial dye concentration, initial pH, ionic strength, acid-activation, calcination and solution temperature. The equilibrium time was 150 min for both dyes. The results showed that alkaline pH was favorable for the adsorption of MY 4GL and MR GRL dyes and physisorption seemed to play a major role in the adsorption process. It was found that the rate of adsorption decreases with increasing temperature and the process is exothermic. The adsorption kinetics followed the pseudo-second-order equation for both dyes investigated in this work with the k 2 values lying in the region of 1.79 x 10 4 to 107.87 x 10 4 g/mol min for MY 4GL and 3.44 x 10 4 to 72.09 x 10 4 g/mol min for MR GRL. The diffusion coefficient values calculated for the dyes were in the range of 3.76 x 10 -9 to 62.50 x 10 -9 cm 2 /s for MY 4GL and 1.98 x 10 -9 to 44.00 x 10 -9 cm 2 /s for MR GRL, and are compatible with other studies reported in the literature. The thermodynamic activation parameters such as the enthalpy, entropy and free energy were determined. The obtained results confirmed the applicability of this clay as an efficient adsorbent for cationic dyes.

  13. Thermical Load Calculation and Capacity of Cooling and Venting Equipment of a Diesel Engine Emissions Study Bench; Calculo de Cargas Termicas y Capacidad de los Equipos de Refrigeracion y Ventilacion de un Banco de Estudio de Emisiones de Motores Diesel

    Energy Technology Data Exchange (ETDEWEB)

    Rojas Garcia, E.; Fonseca Gonzalez, N. A.

    2005-07-01

    The present report tries to develop the calculation of thermical loads and to define the capacity of the equipments of cooling and ventilation that should have the engines test bench that is being ensemble in the installation of the CIEMAT named {sup D}iesel engine emissions study bench (E65-P0). The test bench is formed essentially by a dynamometrical brake and an engine connected at previous one, both of them inside a cabin of isolation acoustic. The thermical loads to be dissipated will be calculated for all the elements that compose the bench and considering his maximum values, to determine the suitable system of cooling air - water of the devices and ventilation in the cabin. (Author) 2 refs.

  14. Electro-osmosis in kaolinite with pH-dependent surface charge modelling by homogenization

    Directory of Open Access Journals (Sweden)

    Sidarta A. Lima

    2010-03-01

    Full Text Available A new three-scale model to describe the coupling between pH-dependent flows and transient ion transport, including adsorption phenomena in kaolinite clays, is proposed. The kaolinite is characterized by three separate nano/micro and macroscopic length scales. The pore (micro-scale is characterized by micro-pores saturated by an aqueous solution containing four monovalent ions and charged solid particles surrounded by thin electrical double layers. The movement of the ions is governed by the Nernst-Planck equations, and the influence of the double layers upon the flow is dictated by the Helmholtz-Smoluchowski slip boundary condition on the tangential velocity. In addition, an adsorption interface condition for the Na+ transportis postulated to capture its retention in the electrical double layer. Thetwo-scalenano/micro model including salt adsorption and slip boundary condition is homogenized to the Darcy scale and leads to the derivation of macroscopic governing equations. One of the notable features of the three-scale model is there construction of the constitutive law of effective partition coefficient that governs the sodium adsorption in the double layer. To illustrate the feasibility of the three-scale model in simulating soil decontamination by electrokinetics, the macroscopic model is discretized by the finite volume method and the desalination of a kaolinite sample by electrokinetics is simulated.Neste artigo propomos um modelo em três escalas para descrever o acoplamento entre o fluxo eletroosmótico e o transporte de íons incluindo fenômenos de adsorção em uma caulinita. A argila é caracterizada por três escalas nano/micro e macroscópica. A escala microscópica é constituída por micro-poros saturados por uma solução aquosa contendo quatro íons monovalentes e partículas sólidas carregadas eletricamente circundadas por uma dupla camada elétrica fina. O movimento dos íons é governado pelas equações de Nernst-Planck e a

  15. Separation of oil palm shell and kernel by using kaolinite media

    Directory of Open Access Journals (Sweden)

    Sukpong Sirinupong

    2003-05-01

    Full Text Available The objective of this research is to investigate the possibility of using kaolinite from Ranong province as media in the oil palm shell and kernel separation process by means of heavy media separation. The effect of specific gravity of the slurry, type and amount of dispersant and type of clays on suspension of media and efficiency of separation were studied. It was found that the specific gravity of oil palm shell and kernel are 1.40 and 1.20 respectively. While the average specific gravity of kaolinite grade MRD-B85, RANONG-325 and commercial clay from Univanich Group. PCL., are 2.54, 2.65 and 2.46 respectively. It was apparent that the viscosity of clay slurry increased with the specific gravity of the slurry. For MRD-B85 and RANONG- 325 clays which have the average particle sizes of 10 and 12 microns, the pH of their slurries of about 5.84 and 6.33 respectively were obtained and at these conditions stability of the slurry rarely occurred and they could not be used for separation. However, these clays can also be utilized as media when dispersant such asCalgon or sodium silicate is applied to their slurries. It was found that the efficiency of separation depends on specific gravity and viscosity of the slurry, type and particle size of kaolinite and dosage of dispersant. The optimum separating conditions for MRD-B85 clay were the dosage of Calgon of 0.15% (or 1.5 kg/t of clay at the specific gravity of the slurry of 1.20-1.24 (27-32% Solids in which a pH of 6.14 and viscosity of 104 cP to very low value (could not be measured were obtained. Thus, kernel yielded 97.57-100% and shell contamination of 1.48-6.32% was achieved. While sodium silicate was applied to the slurry about 0.15% at the specific gravity of 1.22, pH of 6.74 and viscosity of 238 cP were obtained and kernel could be recovered 100% with shell contamination of 8.36%. When 0.15% Calgon or 0.25% sodium silicate was introduced to the RANONG-325 clay slurry at the specific gravity

  16. Testing typicality in multiverse cosmology

    Science.gov (United States)

    Azhar, Feraz

    2015-05-01

    In extracting predictions from theories that describe a multiverse, we face the difficulty that we must assess probability distributions over possible observations prescribed not just by an underlying theory, but by a theory together with a conditionalization scheme that allows for (anthropic) selection effects. This means we usually need to compare distributions that are consistent with a broad range of possible observations with actual experimental data. One controversial means of making this comparison is by invoking the "principle of mediocrity": that is, the principle that we are typical of the reference class implicit in the conjunction of the theory and the conditionalization scheme. In this paper, we quantitatively assess the principle of mediocrity in a range of cosmological settings, employing "xerographic distributions" to impose a variety of assumptions regarding typicality. We find that for a fixed theory, the assumption that we are typical gives rise to higher likelihoods for our observations. If, however, one allows both the underlying theory and the assumption of typicality to vary, then the assumption of typicality does not always provide the highest likelihoods. Interpreted from a Bayesian perspective, these results support the claim that when one has the freedom to consider different combinations of theories and xerographic distributions (or different "frameworks"), one should favor the framework that has the highest posterior probability; and then from this framework one can infer, in particular, how typical we are. In this way, the invocation of the principle of mediocrity is more questionable than has been recently claimed.

  17. Evaluation of kaolinite clays of Moa for the production of cement based clinker-calcined clay-limestone (LC3

    Directory of Open Access Journals (Sweden)

    Roger S. Almenares-Reyes

    2016-12-01

    Full Text Available Clay materials from two outcrops of the Moa region were analyzed to determine their potential use as supplementary cementitious material in the production of ternary cements based on limestone-calcined clay. The clays were characterized by atomic absorption spectroscopy (EAA, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (ATG. These methods revealed high aluminum in clays, moderate kaolinite content, a disordered structure and the presence of impurities. The solubility of aluminum and silicon in alkali and the compressive strength of LC3 systems is proportional to their content in clay, being higher for the one with higher kaolinite content and greater structural disorder (outcrop D1, although the clay of both outcrops may constitute supplementary cementitious materials in the production of ternary cements based clinker-calcined clay-limestone. The suitable thermal activation range for both clays is between 650 ° C and 850 ° C.

  18. Comment on "A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study" and "Infrared and infrared emission spectroscopic study of typical Chinese kaolinite and halloysite" by Hongfei Cheng et al. (2010).

    Science.gov (United States)

    Kloprogge, J Theo

    2015-02-05

    In two papers Cheng et al. (2010) reported in this journal on the mid-infrared, near-infrared and infrared emission spectroscopy of a halloysite from Hunan Xianrenwan, China. This halloysite contains around 8% of quartz (SiO2) and nearly 9% gibbsite (Al(OH)3). In their interpretation of the spectra these impurities were completely ignored. Careful comparison with a phase pure halloysite from Southern Belgium, synthetic gibbsite, gibbsite from Minas Gerais, and quartz show that these impurities do have a marked influence on the mid-infrared and infrared emission spectra. In the near-infrared, the effect is much less pronounced. Quartz does not show bands in this region and the gibbsite bands will be very weak. Comparison still show that the presence of gibbsite does contribute to the overall spectrum and bands that were ascribed to the halloysite alone do coincide with those of gibbsite. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Preparation and characterization of polyacrylamide-modified kaolinite containing poly [acrylic acid-co-methylene bisacrylamide] nanocomposite hydrogels

    DEFF Research Database (Denmark)

    Zaharia, Anamaria; Sarbu, Andrei; Radu, Anita-Laura

    2015-01-01

    Novel nanocomposite hydrogel structures based on cross-linked poly(acrylic acid) (PAA) and kaolinite (Kaol), modified with different loadings of polyacrylamide (PAAm), were prepared by inverse dispersion polymerization. Ceric ammonium nitrate as an initiator in the presence of nitric acid was used...... of Kaol particles in the polyacrylic acid matrix, thereby leading to enhanced interactions and furthermore to improved mechanical properties of the final hydrogels....

  20. Sorption of cobalt in zeolites and natural clays of the clinoptilolite and kaolinite type

    International Nuclear Information System (INIS)

    Davila R, J.I.; Solache R, M.

    2006-01-01

    In this work the sorption of cobalt of aqueous solutions in two natural zeolites (clinoptilolite) and a clay (kaolinite) of origin in the center-north region of Mexico is evaluated. The effect of the pH and the time of contact in the process of sorption were evaluated. The cobalt retained in the aluminosilicates was determined by neutron activation analysis. The cobalt sorption in the materials in a range of pH from 4 to 7 does not present significant variations. The studies of reaction kinetics show a very fast sorption in the first 5 hours of contact, reaching the equilibrium in approximately 24 hours. The kinetics of sorption of the cobalt ions was represented better by the Ritchie reaction model modified of second order. The experimental data for the zeolites obtained at ambient temperature and varying the concentration were adjusted to the models of Freundlich, Langmuir and Freundlich-Langmuir isotherms and it was observed that the cobalt sorption it behaves according to the Freundlich isotherm model. (Author)

  1. Experimental study and mathematical model on remediation of Cd spiked kaolinite by electrokinetics

    International Nuclear Information System (INIS)

    Mascia, Michele; Palmas, Simonetta; Polcaro, Anna Maria; Vacca, Annalisa; Muntoni, Aldo

    2007-01-01

    An experimental study on electrokinetic removal of cadmium from kaolinitic clays is presented in this work, which is aimed to investigate the effect of surface reactions on the electrokinetic process. Enhanced electrokinetic tests were performed in which the pH of the compartments was controlled. Cadmium spiked kaolin was adopted in the experimental runs. On the basis of the experimental results, a numerical model was formulated to simulate the cadmium (Cd) transport under an electric field by combining a one-dimensional diffusion-advection model with a geochemical model: the combined model describes the contaminant transport driven by chemical and electrical gradients, as well as the effect of the surface reactions. The geochemical model utilized parameters derived from the literature, and it was validated by experimental data obtained by sorption and titration experiments. Electrokinetic tests were utilized to validate the results of the proposed model. A good prediction of the behaviour of the soil/cadmium ions system under electrical field was obtained: the differences between experimental and model predicted profiles for the species considered were less than 5% in all the examined conditions

  2. Sorption of lambda-cyhalothrin, cypermethrin, deltamethrin and fenvalerate to quartz, corundum, kaolinite and montmorillonite.

    Science.gov (United States)

    Oudou, H Chaaieri; Hansen, H C Bruun

    2002-12-01

    Sorption to mineral surfaces may be important for retention and degradation of hydrophobic pesticides in subsoils and aquifers poor in organic matter. In this work the title pyrethroids have been used to investigate selective interactions with the surfaces of four minerals. Sorption of the four pyrethroids was quantified in batch experiments with initial pyrethroid concentrations of 1-100 microg/l. Sorption to centrifuge tubes used in the batch experiments accounted for 25-60% of total sorption. Net sorption was obtained from total sorption after subtracting the amounts of pyrethroids sorbed to centrifuge tubes used. All isotherms could be fitted by the Freundlich equation with n ranging between 0.9 and 1.1. Bonding affinities per unit surface area decreased in the order: corundum > quartz > montmorillonite approximately equal kaolinite. A similar sequence as found for the total surface tension of the minerals. All minerals showed the same selectivity order with respect to sorption affinity of the four pyrethroids: lambda-cyhalothrin > deltamethrin > cypermethrin > fenvalerate, which shows that the most hydrophobic compound is sorbed most strongly. Stereochemical properties of the four pyrethroid formulations may also contribute to the selectivity pattern.

  3. Adsorption of Sr on kaolinite, illite and montmorillonite at high ionic strengths

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J.J.; Langmuir, D. (Colorado School of Mines, Golden (USA). Dept. of Chemistry and Geochemistry)

    1991-01-01

    Experimental measurements of Sr adsorption onto kaolinite, illite and montmorillonite in up to 4.0 mol/kg NaCl solutions, were modelled with the surface ionization and complexation triple-layer (SIC) model (Davis et al.) to determine if model adjustments were required for high ionic strengths. Improved model fits to the adsorption data were obtained at high ionic strengths, reflecting a lowered sensitivity of the model. A general reduction in Sr adsorption with increasing ionic strength was caused by an increase in the outer layer surface charge, rather than by a drop in the number of available adsorption sites. Sensitivity analysis showed that the range of values of model constants yielding acceptable fits was as large as variations reported in the literature for these constants. The study demonstrates that adsorption will not retard Sr migration in brines, and that it is unnecessary to introduce a Pitzer ion interaction subroutine in the SIC model when considering adsorption at high ionic strengths. (orig.).

  4. On the Kaolinite Floc Size at the Steady State of Flocculation in a Turbulent Flow.

    Science.gov (United States)

    Zhu, Zhongfan; Wang, Hongrui; Yu, Jingshan; Dou, Jie

    2016-01-01

    The flocculation of cohesive fine-grained sediment plays an important role in the transport characteristics of pollutants and nutrients absorbed on the surface of sediment in estuarine and coastal waters through the complex processes of sediment transport, deposition, resuspension and consolidation. Many laboratory experiments have been carried out to investigate the influence of different flow shear conditions on the floc size at the steady state of flocculation in the shear flow. Most of these experiments reported that the floc size decreases with increasing shear stresses and used a power law to express this dependence. In this study, we performed a Couette-flow experiment to measure the size of the kaolinite floc through sampling observation and an image analysis system at the steady state of flocculation under six flow shear conditions. The results show that the negative correlation of the floc size on the flow shear occurs only at high shear conditions, whereas at low shear conditions, the floc size increases with increasing turbulent shear stresses regardless of electrolyte conditions. Increasing electrolyte conditions and the initial particle concentration could lead to a larger steady-state floc size.

  5. Interactions Between Suspended Kaolinite Deposition and Hyporheic Exchange Flux Under Losing and Gaining Flow Conditions

    Science.gov (United States)

    Fox, Aryeh; Packman, Aaron I.; Boano, Fulvio; Phillips, Colin B.; Arnon, Shai

    2018-05-01

    Fine particle deposition and streambed clogging affect many ecological and biogeochemical processes, but little is known about the effects of groundwater flow into and out of rivers on clogging. We evaluated the effects of losing and gaining flow on the deposition of suspended kaolinite clay particles in a sand streambed and the resulting changes in rates and patterns of hyporheic exchange flux (HEF). Observations of clay deposition from the water column, clay accumulation in the streambed sediments, and water exchange with the bed demonstrated that clay deposition in the bed substantially reduced both HEF and the size of the hyporheic zone. Clay deposition and HEF were strongly coupled, leading to rapid clogging in areas of water and clay influx into the bed. Local clogging diverted exchanged water laterally, producing clay deposit layers that reduced vertical hyporheic flow and favored horizontal flow. Under gaining conditions, HEF was spatially constrained by upwelling water, which focused clay deposition in a small region on the upstream side of each bed form. Because the area of inflow into the bed was smallest under gaining conditions, local clogging required less clay mass under gaining conditions than neutral or losing conditions. These results indicate that losing and gaining flow conditions need to be considered in assessments of hyporheic exchange, fine particle dynamics in streams, and streambed clogging and restoration.

  6. Adsorption behavior of strontium on kaolinite and montmorillonite and their mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Atun, G. [Istanbul Univ. (Turkey). Engineering Faculty, Chemistry Dept.; Bascetin, E. [Cekmece Nuclear Research and Training Center, Istanbul (Turkey)

    2004-07-01

    {sup 90}Sr, with a long half-life of 28.5 years, is the most dangerous strontium isotope. The adsorption behavior of radionuclides in the environment are closely related to the safe disposal of radioactive wastes. Since various types of minerals may exist in and around the repositories used for ultimate disposal of nuclear waste, the adsorption behavior of certain radionuclides onto and from these minerals and similar adsorbents should be studied in order to estimate the rates of transport of the nuclides in the event of water penetration into and through the repository. Information on the adsorption properties of the purified individual clay minerals may not be sufficient to predict the adsorption properties of a corresponding mixture, because these clay minerals may interact with each other and lead to modification of the adsorption properties of the mixture as compared to the pure minerals. The adsorption behavior of strontium on kaolinite and montmorillonite minerals and their mixtures was studied by means of a batch method and a tracer technique. (orig.)

  7. Adsorption of barium on kaolinite, illite and montmorillonite at various ionic strengths

    Energy Technology Data Exchange (ETDEWEB)

    Atun, G.; Bascetin, E. [Istanbul Univ., Dept. of Chemistry, Istanbul (Turkey)

    2003-07-01

    The sorption behaviour of Ba{sup 2+} in three different clay minerals from various regions of Turkey has been investigated by means of a tracer technique using {sup 133}Ba in batch experiments. Sorption of Ba{sup 2+} on montmorillonite, kaolinite and illite has been studied in mixed solutions of BaCl{sub 2} and NaCl at ionic strengths ranging from 1 x 10{sup -3}M to 1 x 10{sup -1}M. The L-shape exchange isotherms for Ba{sup 2+}-Na{sup +} systems are well defined by a Langmuir type equation. The exchange capacity of Ba{sup 2+} ions for all three clay minerals increased with decreasing ionic strength. The adsorption data were fitted to a Freundlich isotherm and empirical Freundlich parameters enabled to the generation of a site distribution function. The selectivity coefficients were nearly constant at low Ba loading and decreased as loading increased. This behavior was an indication of an ion exchange process between Ba{sup 2+} and Na{sup +} ions.

  8. Adhesion of the clay minerals montmorillonite, kaolinite, and attapulgite reduces respiration of Histoplasma capsulatum.

    Science.gov (United States)

    Lavie, S; Stotzky, G

    1986-01-01

    The respiration of three phenotypes of Histoplasma capsulatum, the causal agent of histoplasmosis in humans, was markedly reduced by low concentrations of montmorillonite but was reduced less by even higher concentrations of kaolinite or attapulgite (palygorskite). The reduction in respiration followed a pattern that suggested saturation-type kinetics: an initial sharp reduction that occurred with low concentrations of clay (0.01 to 0.5% [wt/vol]), followed by a more gradual reduction with higher concentrations (1 to 8%). Increases in viscosity (which could impair the movement of O2) caused by the clays were not responsible for the reduction in respiration, and the clays did not interfere with the availability of nutrients. Scanning electron microscopy after extensive washing showed that the clay particles were tightly bound to the hyphae, suggesting that the clays reduced the rate of respiration of H. capsulatum by adhering to the mycelial surface and, thereby, interfered with the movement of nutrients, metabolites, and gases across the mycelial wall.

  9. Behaviour of the surface hydroxide groups of exfoliated kaolinite in the gas phase and during water adsorption.

    Science.gov (United States)

    Táborosi, Attila; Szilágyi, Róbert K

    2016-02-14

    The chemical and physical properties, and thus the reactivity of phylloaluminosilicates can be tailored by intercalation, delamination, and exfoliation processes. In going from the periodic crystalline to the molecular exfoliated phase, surface defects and modifications gain importance as each face of the phylloaluminosilicate comes in direct contact with the external chemical environment. In this work, we extend our earlier studies on the molecular cluster modelling of exfoliated kaolinite sheets by evaluating the positions and orientations of surface hydroxide groups and bridging oxide anions, as the sites of reactivity. The previous focus on the inner chemical environment of a single kaolinite layer is shifted to the surface exposed octahedral aluminium-hydroxide and tetrahedral silicon-oxide sheets. The combination of semi-empirical, ab initio wave function, and density functional calculations unanimously support the amphoteric nature of the surface hydroxide groups with respect to H-bonding donor/acceptor capabilities. To a lesser extent, we observe the same for the bridging oxide anions. This is in contrast to the crystalline phase, which manifests only donor orientation for maintaining an inter-layer H-bond network. These results suggest that both electrophilic and nucleophilic characteristics of the octahedral and tetrahedral sheets need to be considered during intercalation and concomitant exfoliation of the kaolinite sheets.

  10. Equilibrium, kinetic and thermodynamic studies of adsorption of Pb(II) from aqueous solution onto Turkish kaolinite clay

    International Nuclear Information System (INIS)

    Sari, Ahmet; Tuzen, Mustafa; Citak, Demirhan; Soylak, Mustafa

    2007-01-01

    The adsorption of Pb(II) onto Turkish (Bandirma region) kaolinite clay was examined in aqueous solution with respect to the pH, adsorbent dosage, contact time, and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 31.75 mg/g at pH 5 and 20 deg. C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (13.78 kJ/mol) indicated that the adsorption of Pb(II) onto kaolinite clay may be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, free energy (ΔG o ), enthalpy (ΔH o ) and entropy (ΔS o ) of adsorption were also calculated. These parameters showed that the adsorption of Pb(II) onto kaolinite clay was feasible, spontaneous and exothermic process in nature. Furthermore, the Lagergren-first-order, pseudo-second-order and the intraparticle diffusion models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetics

  11. Amazon kaolinite functionalized with diethylenetriamine moieties for U(VI) removal: Thermodynamic of cation-basic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Denis L., E-mail: denis@cpd.ufmt.br [Universidade Federal de Mato Grosso, UFMT, Centro de Recursos Minerais, Cuiaba, Mato Grosso, 78060 900 (Brazil); Leidens, Victor L.; Viana, Rubia R. [Universidade Federal de Mato Grosso, UFMT, Centro de Recursos Minerais, Cuiaba, Mato Grosso, 78060 900 (Brazil); Airoldi, Claudio [Chemistry Institute, State University of Campinas, P.O. Box 6154, 13084-971 Campinas, Sao Paulo (Brazil)

    2010-08-15

    The compound N-[3-(trimethoxysilyl)propyl]diethylenetriamine (MPDET) was anchored onto Amazon kaolinite surface (KLT) by heterogeneous route. The modified and natural kaolinite clay samples were characterized by transmission electron microscopy (TEM), scanning electron microscopic (SEM), N{sub 2} adsorption, powder X-ray diffraction, thermal analysis, ion exchange capacities, and nuclear magnetic nuclei of {sup 29}Si and {sup 13}C. The well-defined peaks obtained in the {sup 13}C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The adsorption of uranyl on natural (KLT) and modified (KLT{sub MPDET}) kaolinite clays was investigated as a function of the solution pH, metal concentration, temperature, and ionic strength. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 8.37 x 10{sup -3} and 13.87 x 10{sup -3} mmol g{sup -1} for KLT and KLT{sub MPDET} at 298 K, respectively. The energetic effects ({Delta}{sub int}H, {Delta}{sub int}G, and {Delta}{sub int}S) caused by metal cations adsorption were determined through calorimetric titrations.

  12. Amazon kaolinite functionalized with diethylenetriamine moieties for U(VI) removal: Thermodynamic of cation-basic interactions

    International Nuclear Information System (INIS)

    Guerra, Denis L.; Leidens, Victor L.; Viana, Rubia R.; Airoldi, Claudio

    2010-01-01

    The compound N-[3-(trimethoxysilyl)propyl]diethylenetriamine (MPDET) was anchored onto Amazon kaolinite surface (KLT) by heterogeneous route. The modified and natural kaolinite clay samples were characterized by transmission electron microscopy (TEM), scanning electron microscopic (SEM), N 2 adsorption, powder X-ray diffraction, thermal analysis, ion exchange capacities, and nuclear magnetic nuclei of 29 Si and 13 C. The well-defined peaks obtained in the 13 C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The adsorption of uranyl on natural (KLT) and modified (KLT MPDET ) kaolinite clays was investigated as a function of the solution pH, metal concentration, temperature, and ionic strength. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 8.37 x 10 -3 and 13.87 x 10 -3 mmol g -1 for KLT and KLT MPDET at 298 K, respectively. The energetic effects (Δ int H, Δ int G, and Δ int S) caused by metal cations adsorption were determined through calorimetric titrations.

  13. Kaolinite and Silica Dispersions in Low-Salinity Environments: Impact on a Water-in-Crude Oil Emulsion Stability

    Directory of Open Access Journals (Sweden)

    Vladimir Alvarado

    2011-10-01

    Full Text Available This research aims at providing evidence of particle suspension contributions to emulsion stability, which has been cited as a contributing factor in crude oil recovery by low-salinity waterflooding. Kaolinite and silica particle dispersions were characterized as functions of brine salinity. A reference aqueous phase, representing reservoir brine, was used and then diluted with distilled water to obtain brines at 10 and 100 times lower Total Dissolved Solid (TDS. Scanning Electron Microscope (SEM and X-ray Diffraction (XRD were used to examine at the morphology and composition of clays. The zeta potential and particle size distribution were also measured. Emulsions were prepared by mixing a crude oil with brine, with and without dispersed particles to investigate emulsion stability. The clay zeta potential as a function of pH was used to investigate the effect of particle charge on emulsion stability. The stability was determined through bottle tests and optical microscopy. Results show that both kaolinite and silica promote emulsion stability. Also, kaolinite, roughly 1 mm in size, stabilizes emulsions better than larger clay particles. Silica particles of larger size (5 µm yielded more stable emulsions than smaller silica particles do. Test results show that clay particles with zero point of charge (ZPC at low pH become less effective at stabilizing emulsions, while silica stabilizes emulsions better at ZPC. These result shed light on emulsion stabilization in low-salinity waterflooding.

  14. Preparation of Composite Hydrogel Based on Polyacrylamide and the Effect of Kaolinite on Its Properties in the Reservoir Conditions

    Directory of Open Access Journals (Sweden)

    Farhad Salimi

    2013-01-01

    Full Text Available A gel composite (based on polyacrylamide and crosslinker Cr(III acetate was prepared by solvent method (distillate and water formation and nanoclay particle (kaolinite. Using XRD tests, d001 was evaluated for kaolinite nanoparticles in gel composite. Kaolinite modification using dimethyl-sulfoxide led to increase interlamellar spacing from 7.21 to 10.82 o A. Based on the results obtained for samples prepared from unmodified clay besides the pure clay, there is a wide peak at 2θ = 8o; which is a representative of polymer diffusion between the clay layers. For the sample prepared from modified clay, no increase in interlamellar space was observed. Addition of 15% clay (modified and unmodified caused the syneresis to reduce by 20%. The gelation time for composites prepared from both types of clays increased due to increases in clay concentration, which this increase for the sample prepared from unmodified clay was greater. The viscosity of gel for samples prepared from modified clay increased due to increased clay concentration, which reached its maximum for 15% clay concentration. However for unmodified clay the maximum value of viscosity was observed for 30% clay concentration.

  15. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jian, E-mail: zhaojian0209@aliyun.com [Institute of Applied Physics and Computational Mathematics, PO Box 8009, Beijing 100088 (China); State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China); He, Man-Chao [State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China)

    2014-10-30

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail.

  16. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    International Nuclear Information System (INIS)

    Zhao, Jian; He, Man-Chao

    2014-01-01

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail

  17. Proceedings of the International Symposium on Frozen Soil Impacts on Agricultural, Range, and Forest Lands Held at Spokane, Washington on March 21-22, 1990

    Science.gov (United States)

    1990-03-01

    the United States. The soils were: a Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludult) from Watkinsville, GA ; a Barnes loam (fine loamy...1987). GLEAMS user manual. Lab Note South East Watershed Research Laboratory 110 187 WGK, Tifton , Ge, 1987. Lane, L.J., and V. A. Ferreira, (1980...as caps for processed uranium mill tailings in the western United States. The purpose of these barriers is to control radon gas release. The soil

  18. A GIS TOOL TO EVALUATE THE SPATIAL EVOLUTION OF HYDRO-THERMIC FEATURES DURING GROWING SEASON OF VEGETABLE CROPS IN ELBE RIVER LOWLAND (POLABI

    Directory of Open Access Journals (Sweden)

    VERA POTOP

    2012-11-01

    Full Text Available A GIS tool to evaluate the spatial evolution of hydro-thermic features during growing season of vegetable crops in Elbe River lowland (Polabi. This article presents the results of the first study on combined mezoclimatological, microclimatological and topographical tools for evaluating precision farming in the growth of vegetable crops in the Elbe River lowland (Polabi region from the Czech Republic. We assess the variability of basically climatological characteristics in relation to topographic characteristics at the regional (Polabi and local (agricultural farm scales. At regional scale, interpolation approach is based on local linear regression and universal kriging interpolation. At local scale, two conventional interpolation methods, spline and local ordinary kriging with a Gaussian model variance across the fields, were applied. The local spline interpolators have been used in developing digital elevation models (DEMs and to determine the slope angle inclination of vegetable fields. The DEMs of the vegetable crops fields was developed at a 10 m x 10 m resolution based on elevation data collected in the field by a hand-held RTK- Global Positioning System receiver. This tool allowed the distinction of microclimatic conditions that produce altitude-slope-related patterns of the spatial-temporal distribution of the basic meteorological elements during growing season of vegetable crops. The effect of slope on diurnal extreme temperatures in the vegetable cropped field conditions was more pronounced than that of elevation. Accordingly to developed maps, the warmest and longest duration of sunshine, and the least precipitation totals during growing season occurred in the middle part of Polabi.

  19. Ginger consumption enhances the thermic effect of food and promotes feelings of satiety without affecting metabolic and hormonal parameters in overweight men: A pilot study

    Science.gov (United States)

    Mansour, Muhammad S.; Ni, Yu-Ming; Roberts, Amy L.; Kelleman, Michael; RoyChoudhury, Arindam; St-Onge, Marie-Pierre

    2012-01-01

    Objective Evidence suggests that ginger consumption has anti-inflammatory, anti-hypertensive, glucose-sensitizing, and stimulatory effects on the gastrointestinal tract. This study assessed the effects of a hot ginger beverage on energy expenditure, feelings of appetite and satiety and metabolic risk factors in overweight men. Methods Ten men, age 39.1 ± 3.3 y and body mass index (BMI) 27.2 ± 0.3 kg/m2, participated in this randomized crossover study. Resting state energy expenditure was measured using indirect calorimetry and for 6 h after consumption of a breakfast meal with or without 2 g ginger powder dissolved in a hot water beverage. Subjective feelings of satiety were assessed hourly using visual analog scales (VAS) and blood samples were taken fasted and for 3 h after breakfast consumption. Results There was no significant effect of ginger on total resting energy expenditure (P = 0.43) or respiratory quotient (P = 0.41). There was a significant effect of ginger on thermic effect of food (ginger vs control = 42.7 ± 21.4 kcal/d, P = 0.049) but the area under the curve was not different (P = 0.43). VAS ratings showed lower hunger (P = 0.002), lower prospective food intake (P = 0.004) and greater fullness (P = 0.064) with ginger consumption versus control. There were no effects of ginger on glucose, insulin, lipids, or inflammatory markers. Conclusions The results, showing enhanced thermogenesis and reduced feelings of hunger with ginger consumption, suggest a potential role of ginger in weight management. Additional studies are necessary to confirm these findings. PMID:22538118

  20. Radiation-Induced Defects in Kaolinite as Tracers of Past Occurrence of Radionuclides in a Natural Analogue of High Level Nuclear Waste Repository

    Science.gov (United States)

    Allard, T.; Fourdrin, C.; Calas, G.

    2007-05-01

    Understanding the processes controlling migrations of radioelements at the Earth's surface is an important issue for the long-term safety assessment of high level nuclear waste repositories (HLNWR). Evidence of past occurrence and transfer of radionuclides can be found using radiation-induced defects in minerals. Clay minerals are particularly relevant because of their widespread occurrence at the Earth's surface and their finely divided nature which provides high contact area with radioactive fluids. Owing to its sensitivity to radiations, kaolinite can be used as natural, in situ dosimeter. Kaolinite is known to contain radiation-induced defects which are detected by Electron Paramagnetic Resonance. They are differentiated by their nature, their production kinetics and their thermal stability. One of these defects is stable at the scale of geological periods and provides a record of past radionuclide occurrence. Based on artificial irradiations, a methodology has been subsequently proposed to determine paleodose cumulated by kaolinite since its formation. The paleodose can be used to derive equivalent radioelement concentrations, provided that the age of kaolinite formation can be constrained. This allows quantitative reconstruction of past transfers of radioelements in natural systems. An example is given for the Nopal I U-deposit (Chihuahua, Mexico), hosted in hydrothermally altered volcanic tufs and considered as analogue of the Yucca Mountain site. The paleodoses experienced by kaolinites were determined from the concentration of defects and dosimetry parameters of experimental irradiations. Using few geochemical assumption, a equivalent U-content responsible for defects in kaolinite was calculated from the paleodose, a dose rate balance and model ages of kaolinites constrained by tectonic phases. In a former study, the ages were assumptions derived from regional tectonic events. In thepresent study, ages of mineralization events are measured from U

  1. PTL: A Propositional Typicality Logic

    CSIR Research Space (South Africa)

    Booth, R

    2012-09-01

    Full Text Available consequence relations first studied by Lehmann and col- leagues in the 90?s play a central role in nonmonotonic reasoning [13, 14]. This has been the case due to at least three main reasons. Firstly, they are based on semantic constructions that are elegant...) j ; 6j : ^ j PTL: A Propositional Typicality Logic 3 The semantics of (propositional) rational consequence is in terms of ranked models. These are partially ordered structures in which the ordering is modular. Definition 1. Given a set S...

  2. Understanding the sorption mechanisms of aflatoxin B1 to kaolinite, illite, and smectite clays via a comparative computational study.

    Science.gov (United States)

    Kang, Fuxing; Ge, Yangyang; Hu, Xiaojie; Goikavi, Caspar; Waigi, Michael Gatheru; Gao, Yanzheng; Ling, Wanting

    2016-12-15

    In current adsorption studies of biotoxins to phyllosilicate clays, multiply weak bonding types regarding these adsorptions are not well known; the major attractive forces, especially for kaolinite and illite, are difficult to be identified as compared to smectite with exchangeable cations. Here, we discriminated the bonding types of aflatoxin B1 (AFB1) contaminant to these clays by combined batch experiment with model computation, expounded their bonding mechanisms which have been not quantitatively described by researchers. The observed adsorbent-to-solution distribution coefficients (K d ) of AFB1 presented in increasing order of 18.5-37.1, 141.6-158.3, and 354.6-484.7L/kg for kaolinite, illite, and smectite, respectively. Normalization of adsorbent-specific surface areas showed that adsorption affinity of AFB1 is mainly dependent on the outside surfaces of clay aggregates. The model computation and test of ionic effect further suggested that weakly electrostatic attractions ((Si/Al-OH) 2 ⋯(OC) 2 ) are responsible for AFB1-kaolinite adsorption (K d , 18.5-37.1L/kg); a moderate electron-donor-acceptor attraction ((CO) 2 ⋯K + ⋯(O-Al) 3 ) is related to AFB1-illite adsorption (K d , 141.6-158.3L/kg); a strong calcium-bridging linkage ((CO) 2 ⋯Ca 2+ ⋯(O-Si) 4 ) is involved in AFB1-smectite adsorption (K d , 354.6-484.7L/kg). Changes in Gibbs free energy (ΔG°) suggested that the computed result is reliable, providing a good reproduction of AFB1-clay interaction. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Probing the Surface Charge on the Basal Planes of Kaolinite Particles with High-Resolution Atomic Force Microscopy.

    Science.gov (United States)

    Kumar, N; Andersson, M P; van den Ende, D; Mugele, F; Siretanu, I

    2017-12-19

    High-resolution atomic force microscopy is used to map the surface charge on the basal planes of kaolinite nanoparticles in an ambient solution of variable pH and NaCl or CaCl 2 concentration. Using DLVO theory with charge regulation, we determine from the measured force-distance curves the surface charge distribution on both the silica-like and the gibbsite-like basal plane of the kaolinite particles. We observe that both basal planes do carry charge that varies with pH and salt concentration. The silica facet was found to be negatively charged at pH 4 and above, whereas the gibbsite facet is positively charged at pH below 7 and negatively charged at pH above 7. Investigations in CaCl 2 at pH 6 show that the surface charge on the gibbsite facet increases for concentration up to 10 mM CaCl 2 and starts to decrease upon further increasing the salt concentration to 50 mM. The increase of surface charge at low concentration is explained by Ca 2+ ion adsorption, while Cl - adsorption at higher CaCl 2 concentrations partially neutralizes the surface charge. Atomic resolution imaging and density functional theory calculations corroborate these observations. They show that hydrated Ca 2+ ions can spontaneously adsorb on the gibbsite facet of the kaolinite particle and form ordered surface structures, while at higher concentrations Cl - ions will co-adsorb, thereby changing the observed ordered surface structure.

  4. Thermally induced permeability reduction due to particle migration in sandstones: the effect of temperature on kaolinite mobilisation and aggregation

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke; Yuan, Hao

    2012-01-01

    The seasonal imbalance in supply and demand of renewable energy requires seasonal storage, which potentially may be achieved by hot water injection in geothermal aquifers to minimize heat loss by advection. A reduction of porosity and permeability is a risk of heating the rock above the in...... the interaction energy between quartz and kaolinite particles for different saturating fluids. The results are compared to the published data addressing the effect of temperature on permeability. This provides a qualitative explanation for the observed changes in permeability with temperature for the tests...

  5. Flash calcination of kaolinite rich clay and impact of process conditions on the quality of the calcines

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2016-01-01

    Use of properly calcined kaolinite rich clay (i.e., metakaolin) to offset part of CO2-intensive clinkers not only reduces CO2 footprint from cement industry but also improves the performance of concrete. However, calcination under inappropriately high temperatures or long retention times may...... suspension calciner. The model is validated by the experimental data (e.g., the degree of dehydroxylation and the density of the calcines). Based on the model, the impacts of process conditions and feed properties on the quality of the calcination products are thoroughly examined....

  6. Application of Brazilian kaolinite clay as adsorbent to removal of U(VI) from aqueous solution: Kinetic and thermodynamic of cation-basic interactions

    International Nuclear Information System (INIS)

    Guerra, Denis L.; Leidens, Victor L.; Viana, Rubia R.; Airoldi, Claudio

    2010-01-01

    The compound N 1 -[3-(trimethoxysilyl)propyl]diethylenetriamine was anchored onto Amazon kaolinite surface by heterogeneous route. The modified and natural kaolinite samples were characterized by transmission electron microscopy, scanning electron microscopic, X-ray diffraction, and nuclear magnetic nuclei of 29 Si and 13 C. The well-defined peaks obtained in the 13 C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k 2 values 16.0 and 25.1 mmol g -1 min -1 ranges for natural and modified kaolinite clays, respectively. The energetic effects caused by metal ion adsorption were determined through calorimetric titrations. - Graphical abstract: This investigation reports the use of original and modified kaolinites as alternative absorbents. The compound N-[3-trimethoxysilyl)propyl]diethylenetriamine was anchored onto Amazon kaolinite surface by heterogeneous route.

  7. Evaluation of mineral kaolinite present in portuguese clays for use in porcelain stoneware; Avaliacao do mineral caulinita presente em argilas portuguesas para uso em gres porcelanato

    Energy Technology Data Exchange (ETDEWEB)

    Luna da Silveira, G.C. [Instituto Federal do Rio Grande do Norte (IFRN), RN (Brazil); Acchar, W.; Gomes, U.U.; Luna da Silveira, R.V. [Universidade Federal do Rio Grnde do Norte (UFRN), RN (Brazil); Labrincha, A.; Miranda, C.M.P., E-mail: glebacoelli@hotmail.com [Universidade de Aveiro (Portugal)

    2016-07-01

    Kaolinite is a mineral from the kaolin, product resulting from transformation in depth of alumino silicate mineral type, such as feldspars, plagioclase and feldspars contained in the rocks. Clays are raw materials that have as main characteristic the plasticity property, which gives the product, after applying a certain pressure, a defined shape and an increase in the mechanical resistance when they become from green to dry and then to sintered. Given these characteristics, this paper analyzes the presence of the existing mineral kaolinite in two portuguese clays who are used in the preparation of formulations of porcelain stoneware tiles. The analyzes of the two clays were made by fluorescence x-ray diffraction of x-rays, thermal analysis, particle size and scanning electron microscopy, to better use of this mineral in the formulations. In both clays were found aluminum oxide, as well as mineral quartz, kaolinite and illite. (author)

  8. Adsorption and structure of water on kaolinite surfaces: possible insight into ice nucleation from grand canonical monte carlo calculations.

    Science.gov (United States)

    Croteau, T; Bertram, A K; Patey, G N

    2008-10-30

    Grand canonical Monte Carlo calculations are used to determine water adsorption and structure on defect-free kaolinite surfaces as a function of relative humidity at 235 K. This information is then used to gain insight into ice nucleation on kaolinite surfaces. Results for both the SPC/E and TIP5P-E water models are compared and demonstrate that the Al-surface [(001) plane] and both protonated and unprotonated edges [(100) plane] strongly adsorb at atmospherically relevant relative humidities. Adsorption on the Al-surface exhibits properties of a first-order process with evidence of collective behavior, whereas adsorption on the edges is essentially continuous and appears dominated by strong water lattice interactions. For the protonated and unprotonated edges no structure that matches hexagonal ice is observed. For the Al-surface some of the water molecules formed hexagonal rings. However, the a o lattice parameter for these rings is significantly different from the corresponding constant for hexagonal ice ( Ih). A misfit strain of 14.0% is calculated between the hexagonal pattern of water adsorbed on the Al-surface and the basal plane of ice Ih. Hence, the ring structures that form on the Al-surface are not expected to be good building-blocks for ice nucleation due to the large misfit strain.

  9. A comparative study on the rheology and wave dissipation of kaolinite and natural Hendijan Coast mud, the Persian Gulf

    Science.gov (United States)

    Soltanpour, Mohsen; Samsami, Farzin

    2011-03-01

    The objective of this paper is to investigate the rheological behavior of kaolinite and Hendijan mud, located at the northwest part of the Persian Gulf, and the dissipative role of this muddy bed on surface water waves. A series of laboratory rheological tests was conducted to investigate the rheological response of mud to rotary and cyclic shear rates. While a viscoplastic Bingham model can successfully be applied for continuous controlled shear-stress tests, the rheology of fluid mud displays complex viscoelastic behavior in time-periodic motion. The comparisons of the behavior of natural Hendijan mud with commercial kaolinite show rheological similarities. A large number of laboratory wave-flume experiments were carried out with a focus on the dissipative role of the fluid mud. Assuming four rheological models of viscous, Kelvin-Voigt viscoelastic, Bingham viscoplastic, and viscoelastic-plastic for fluid mud layer, a numerical multi-layered model was applied to analyze the effects of different parameters of surface wave and muddy bed on wave attenuation. The predicted results based on different rheological models generally agree with the obtained wave-flume data implying that the adopted rheological model does not play an important role in the accuracy of prediction.

  10. Intracrystalline fractionation of oxygen isotopes between hydroxyl and non-hydroxyl sites in kaolinite measured by thermal dehydroxylation and partial fluorination

    Science.gov (United States)

    Girard, Jean-Pierre; Savin, Samuel M.

    1996-02-01

    Thermal dehydroxylation and partial fluorination techniques were used to measure intracrystalline fractionation of oxygen isotopes between hydroxyl and non-hydroxyl sites in kaolinite. Several aliquots of a well characterized, fine-grained (rates, and target temperatures. Measured δ18O values of both the liberated water and the dehydroxylated residue are consistent over a wide range of temperatures (550 850°C) when dehydroxylation is performed in a single-step fashion at a rapid heating rate (>50°C/min.). Similar dehydroxylation experiments indicate that brucite dehydroxylation occurs without any significant isotopic fractionation of the oxygen isotopes. By extrapolation we postulate that no significant fractionation occurs during single-step thermal dehydroxylation of fine-grained kaolinite, provided that dehydroxylation is performed under well controlled conditions. In contrast, gibbsite dehydroxylation is accompanied by substantial isotopic fractionation. This is probably the result of the complex, multi-pathway dehydroxylation reaction of this mineral. Similarly, thermal dehydroxylation of coarsegrained (>1 μm) kaolinites and dickites of weathering and hydrothermal origin yield results that are dependent on the temperature of dehydroxylation. We suggest that this effect may be caused by isotopic exchange during diffusion of water molecules through coarse particles. Partial fluorination of fine-grained kaolinite in the presence of excess F2 at low temperatures (rate of reaction of hydroxyl oxygen than of non-hydroxyl oxygen, but examination of the isotopic data as well as XRD and IR analyses of the residues after partial fluorination indicates that the separation between the two types of oxygen is not complete. The results, therefore, do not yield a reliable δ18O value of the hydroxyl oxygen. The results of this study suggest that the thermal dehydroxylation technique may be appropriate for analysis of OH groups in fine-grained kaolinite. The partial

  11. Evaluation of the nanoparticle treatment effect on the development of nanocomposite resin epoxy/kaolinite;Avaliacao do efeito do tratamento da nanoparticula no desenvolvimento de nanocomposito resina epoxi/caulinita

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Tharsia C.C.; Mendonca, Rannier M., E-mail: tharsia@gmail.co [Universidade Federal do Rio Grande do Norte (PPGCEM/UFRN), Natal (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Ito, Edson N; Melo, Jose D.D.; Paskocimas, Carlos A., E-mail: ito@ufrnet.b [Universidade Federal do Rio Grande do Norte (DEMat/UFRN), Natal (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    The nanocomposites formed from polymer matrices and mineral clays have been studied since the decade of 60s when Blumstein demonstrated the intercalation the polymer molecules between lamellae of montmorillonite. The application of the kaolinite in nanocomposite polymeric is rare, however the kaolinite is expandable and it is possible to do the process of the superficial functionalization. The present work demonstrates that after leaching process of the kaolinite through a chemical treatment with hydrogen peroxide combined with acid solutions the kaolinite inside presents a surface activated with good resulted of dispersion of a polymers matrix by a mechanical agitation, in high-energy mill. The samples had been characterized by x-ray diffraction, thermogravimetry (TGA) and transmission electron microscopy (TEM). The results showed the potential of using the functionalized kaolinite as an agent of reinforcement in polymer nanocomposites. (author)

  12. Adsorption of Zn(II) on the kaolinite(001) surfaces in aqueous environment: A combined DFT and molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiang; Kong, Xiang-Ping; Zhang, Bao-Hua; Wang, Juan, E-mail: juaner80@163.com

    2017-08-31

    Highlights: • Zn(II) adsorption on two types of neutral kaolinite(001) surfaces is investigated. • Surface “Ou” is found the preferred site for mono- and bi-dentate complexes. • Both Zn(II) and surface oxygen accept electrons from aqua oxygens. • Coupling of O 2p with Zn sp{sup 3}d{sup 2} (or sp{sup 3}) hybridization states is the bonding nature. - Abstract: Adsorption of Zn(II) on two types of neutral (001) surfaces of kaolinite, tetrahedral Si(t) and octahedral Al(o), was studied by means of DFT calculations and classical molecular dynamics simulations. The position and structure for both outer-sphere and mono-/bi-dentate inner-sphere complexes of Zn(II) in aqueous environment were examined, with binding energy and radial distribution function calculated. Outer-sphere complex on the Si(t) surface, monodentate inner-sphere complex of “O{sub u}” (surface oxygen with “upright” hydrogen) site and bidentate complex of “O{sub u}-O{sub u}” site of neighboring Al centers on the Al(o) surface are considered to be the dominant adsorption species. The outer-sphere complex is found six-coordinated with distorted octahedral geometry, while both the inner-sphere complexes exhibit the tetrahedral structure with coordination number of four. Hydrogen bonding interactions between oxygen or hydrogen of the kaolinite(001) surfaces and the aqua ligands of Zn(II) act as the key role for the structure and stability of adsorption complexes. Upon the Mulliken population analysis and partial density of states, both Zn(II) and surface oxygen accept electrons from aqua oxygens, and coupling of O 2p with the sp{sup 3}d{sup 2} or sp{sup 3} hybridization states of Zn(II) is the primary bonding nature of Zn(II) with oxygen in outer- and inner-sphere complexes, respectively.

  13. Removal of radiocobalt from aqueous solutions by kaolinite affected by solid content, pH, ionic strength, contact time and temperature

    International Nuclear Information System (INIS)

    Kan Li; Zhengjie Liu; Lei Chen; Yunhui Dong; Jun Hu; Chinese Academy of Sciences, Hefei

    2013-01-01

    The kaolinite sample was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction, and was applied as adsorbent for the removal of radiocobalt ions from radioactive wastewater. The results demonstrated that the sorption of Co(II) was strongly dependent on pH and ionic strength at low pH values, and independent of pH and ionic strength at high pH values. The sorption of Co(II) was dominated by outer-sphere surface complexation or ion exchange at low pH values, whereas inner-sphere surface complexation was the main sorption mechanism at high pH values. The sorption isotherms were well described by Langmuir, Freundlich and Dubinin-Radushkevich models. The thermodynamic parameters (i.e., ΔGdeg, ΔSdeg, ΔHdeg) calculated from the temperature-dependent sorption isotherms indicated that the sorption of Co(II) on kaolinite was an endothermic and spontaneous process. The results of high sorption capacity of kaolinite suggested that the kaolinite sample was a suitable material for the preconcentration of Co(II) from large volumes of aqueous solutions and as backfill materials in nuclear waste management. (author)

  14. Mineralogical and crystallochemical transformations originated from thermal essays on ferruginous kaolinitic clays; Transformacoes mineralogicas e cristaloquimicas decorrentes dos ensaios termais em argilas cauliniticas ferruginosas

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.M.; Varajao, A.F.D.C.; Morales-Carrera, A.M.; Peralta-Sanchez, M.G.; Costa, G.M. da, E-mail: angelica@degeo.ufop.br [Universidade Federal de Ouro Preto, Campus Universitario, Morro do Cruzeiro s/n, Ouro Preto, MG (Brazil)

    2012-01-15

    Mineralogical and crystallochemical transformations of representative ferruginous kaolinitic clay samples were investigated in specimens burned at 800, 1000 and 1200 deg C. X-ray diffraction and differential thermal and thermogravimetric analyses showed that kaolinite was the predominant mineral in the raw samples. The Moessbauer spectroscopy results showed that the high iron content (22.5 wt.%), as determined by X-ray fluorescence, is related to the presence of goethite (18 wt.%) and hematite (16 wt.%). However, after Fe was extracted using a dithionite-citrate system buffered with sodium bicarbonate, a residue of this element (Fe{sup 3+} and Fe{sup 2+}) was found in the structure of the kaolinite. The sintering process showed the destruction of kaolinite, as well as the transformation of the goethite into hematite, the crystals growing as the temperature increases. The hematite crystal size at 1200 deg C is five times larger than in the raw sample. The mullite formation at 1000 deg C is comprised of a solid solution of Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3},which results in a resistant product with a higher thermal stability (author)

  15. Nucleation and growth process of sodalite and cancrinite from kaolinite-rich clay under low-temperature hydrothermal conditions

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Ríos Reyes

    2013-04-01

    Full Text Available The synthesis of low-silica zeotypes by hydrothermal transformation of kaolinite-rich clay and the nucleation and growth processes of sodalite and cancrinite in the system Na2O-Al2O3-SiO2-H2O at 100 °C were investigated. The synthesis products were characterized by X-ray powder diffraction (XRPD, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FT-IR, 29Si and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR and thermogravimetric analysis (TGA. Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → zeolite LTA → sodalite → sodalite + cancrinite → cancrinite. Synthesized materials appeared stable thermodynamically under the experimental conditions, with zeolite LTA (a metastable phase occurring as a minor phase, compared with the presence of sodalite and cancrinite.

  16. Application of surface complexation modelling: Nickel sorption on quartz, manganese oxide, kaolinite and goethite, and thorium on silica

    International Nuclear Information System (INIS)

    Olin, M.; Lehikoinen, J.

    1997-12-01

    The study is a follow-up to a previous modelling task on mechanistic sorption. The experimental work has been carried out at the Laboratory of Radiochemistry, University of Helsinki (HYRL), and the sorption modelling was performed using the HYDRAQL code. Parameters taken from the open literature were employed in the modelling phase. The thermodynamic data for aqueous solutions were extracted from the EQ3/6 database and subsequently modified for HYDRAQL where necessary. The experimental data were obtained from five different experiments, four of which concerned the adsorption of nickel. The first experimental system was a mixture of Nilsiae quartz and manganese dioxide. In the second experiment, quartz was equilibrated with a fresh and saline groundwater simulant instead of an electrolyte solution. The third and fourth experiments dealt with nickel adsorption from an electrolyte solution onto goethite and kaolinite surfaces respectively. In the fifth experiment, adsorption of thorium onto a quartz surface was investigated

  17. Effect of the acid treatment conditions of kaolinite on etheramine adsorption: A comparative analysis using chemometric tools.

    Science.gov (United States)

    Leal, Paulo Vitor Brandão; Magriotis, Zuy Maria; Sales, Priscila Ferreira de; Papini, Rísia Magriotis; Viana, Paulo Roberto de Magalhães

    2017-07-15

    The present work evaluated the effect of the acid treatment conditions of natural kaolinite (NK) regarding its efficiency in removing etheramine. The treatment was conducted using sulfuric acid at the concentrations of 1 mol L -1 (KA-01), 2 mol L -1 (KA-02) and 5 mol L -1 (KA-05) at 85 °C. The obtained adsorbents were characterized by X-ray fluorescence, X-ray diffraction, N 2 adsorption/desorption isotherms, zeta potential analysis and infrared spectroscopy. The Response Surface Method was used to optimize adsorption parameters (initial concentration of etheramine, adsorbent mass and pH of the solution). The results, described by means of a central composite design, were adjusted to the quadratic model. Results revealed that the adsorption was more efficient at the etheramine concentration of 400 mg L -1 , pH 10 and adsorbent mass of 0.1 g for NK and 0.2 g for KA-01, KA-02 and KA-05. The sample KA-02 presented a significant increase of etheramine removal compared to the NK sample. The adsorption kinetics conducted under optimized conditions showed that the system reached the equilibrium in approximately 30 min. The kinetic data were better adjusted to the pseudo-second order model. The isotherm data revealed that the Sips model was the most adequate one. The calculation of E ads allowed to infer that the mechanism for etheramine removal in all the evaluated samples was chemisorption. The reuse tests showed that, after four uses, the efficiency of adsorbents in removing etheramine did not suffer significant modifications, which makes the use of kaolinite to treat effluents from the reverse flotation of iron ore feasible. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Interestratificado caulinita-esmectita em um argissolo desenvolvido a partir de rocha sedimentar do Sul do Brasil Interlayered kaolinite-smectite minerals in an acrisol developed from sandstone parent material in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2007-12-01

    , indicando que ela é proveniente de herança do material de origem. A mineralogia deste solo indica estádio intermediário entre argilominerais de estrutura do tipo 2:1 e 1:1 no processo de intemperismo.Kaolinite is commonly found in fine fractions of tropical and subtropical Brazilian soils. Kaolinite can be verified by an X-ray diffractogram, made of a series of 00l peaks, at the distance of 0.715 nm. However, in some soils, major peaks can be found at about d = 0.720 nm, indicating halloysite or kaolinite-smectite (K-S interstratified minerals. The objectives of this study were to verify this hypothesis and subsequently discuss soil genesis. Parent material and soil samples from the horizons A1, A2, E and Bt were collected in a Red Yellow Acrisol, covered by native vegetation, on the Campus of the Universidade Federal de Santa Maria, RS, Brazil. The clay fraction was separated by sedimentation, Ca2+ saturated and X-ray diffracted after the following treatments: control, air drying, (N; ethylene-glycol saturation (EG; heating to 300 and 550 °C; and, after formamide saturation. The raw X-ray diffractograms (XRD were modeled between 11 and 15 degrees 2 theta (using DecompRX. Two peaks were found in the XRD around this region. The first peak was sharp and intense at d = 0.717 nm, corresponding to kaolinite; the second, broader and less intense, was observed at d = 0.720 nm. The peak at d = 0.720 nm was sensitive to EG treatment; it varied from d = 0.720 nm to d = 0.730 nm and returned to about d = 0.720 nm after heating to 300 °C. This behaviour is typical of expansive layers. The presence of interstratified K-S minerals was inferred since halloysite clay was not identified by the formamide test. The XRD were analyzed and indicated interstratified K-S mineral at a proportion of 0.8_0.9 kaolinite layers and 0.1-0.2 smectite layers. Furthermore, the K-S covered about 90 % and kaolinite alone 10 % of the modelled peak, at d = 0.720 nm. K-S was also found in the bedrock

  19. Typicality and misinformation: Two sources of distortion

    Directory of Open Access Journals (Sweden)

    Malen Migueles

    2008-01-01

    Full Text Available This study examined the effect of two sources of memory error: exposure to post-event information and extracting typical contents from schemata. Participants were shown a video of a bank robbery and presented with highand low-typicality misinformation extracted from two normative studies. The misleading suggestions consisted of either changes in the original video information or additions of completely new contents. In the subsequent recognition task the post-event misinformation produced memory impairment. The participants used the underlying schema of the event to extract high-typicality information which had become integrated with episodic information, thus giving rise to more hits and false alarms for these items. However, the effect of exposure to misinformation was greater on low-typicality items. There were no differences between changed or added information, but there were more false alarms when a low-typicality item was changed to a high-typicality item

  20. Development of Surface Complexation Models of Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, γ-Alumina, Hydrous Manganese and Ferric Oxides and Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Koretsky, Carla [Western Michigan University

    2013-11-29

    hexavalent chromium, especially at low pH. Unexpectedly, experiments with the clay minerals kaolinite and montmorillonite suggest that hexavalent chromium may interact with these solids over much longer periods of time than expected. Furthermore, hexavalent chromium may irreversibly bind to these solids, perhaps because of oxidation-reduction reactions occurring on the surfaces of the clay minerals. More work should be done to investigate and quantify these chemical reactions. Experiments conducted with mixtures of goethite, hydrous manganese oxide, hydrous ferric oxide, γ-alumina, montmorillonite and kaolinite demonstrate that it is possible to correctly predict hexavalent chromium binding in the presence of multiple minerals using thermodynamic models derived for the simpler systems. Further, these models suggest that of the six solid considered in this study, goethite is typically the solid to which most of the hexavalent chromium will bind. Experiments completed with organic-rich and organic-poor natural sediments demonstrate that in organic-rich substrates, organic matter is likely to control uptake of the hexavalent chromium. The models derived and tested in this study for hexavalent chromium binding to γ-alumina, hydrous manganese oxide, goethite, hydrous ferric oxide and clay minerals can be used to better predict changes in hexavalent chromium bioavailability and mobility in contaminated sediments and soils.

  1. Heterogeneous reactions of dioctahedral smectites in illite-smectite and kaolinite-smectite mixed-layers: applications to clay materials for engineered barriers

    International Nuclear Information System (INIS)

    Meunier, A.; Proust, D.; Beaufort, D.; Lajudie, A.; Petit, J.-C.

    1992-01-01

    The clay materials selected for use in the engineered barriers of the French nuclear waste isolation programme are mainly composed of dioctahedral smectite, either bentonite of Wyoming type or kaolinite-smectites most often consist of randomly stacked layers with low and high charges. In the case of the Wyoming-type bentonite, these two differently charged layers do not react in the same way when subjected to hydrothermal alteration. Overall, the low-charge smectite layers react to form high-charge smectite layers + quartz + kaolinite. Then, fixing K ions, the high-charge smectite layers are transformed into illite-smectite mixed-layers (I/S) when the temperature conditions increase. A symmetrical process is observed in natural or experimental hydrothermal conditions when the high-charge smectite layers of I/S minerals react with quartz and/or kaolinite to produce low-charge smectite layers. The chemical properties of the bentonite-engineered barriers clearly depend on the low charge/high charge smectite layer proportion, which is in turn controlled by the temperature-dependent reactions in the vicinity of the waste disposal. Although there are fewer published data on the kaolinite-smectite mixed-layered minerals (K/S), a similar low charge-high charge reaction appears to affect their smectite component. The experimental alteration of K/S leads to the formation of a low-charge beidellite with an increase in the cation-exchange capacity and in the expandability of the clay material. Thus, the properties of the engineered barrier seems to be improved after hydrothermal alteration. (Author)

  2. Surface complexation modelling: Experiments on sorption of nickel on quartz, goethite and kaolinite and preliminary tests on sorption of thorium on quartz

    Energy Technology Data Exchange (ETDEWEB)

    Puukko, E.; Hakanen, M. [Univ. of Helsinki (Finland). Dept. of Chemistry. Lab. of Radiochemistry

    1997-09-01

    The aim of the work was to study the sorption behaviour of Ni on quartz, goethite and kaolinite at different pH levels and in different electrolyte solutions of different strength. In addition preliminary experiments were made to study the sorption of thorium on quartz. The MUS quartz and Nilsiae quartz were analysed for MnO{sub 2} by neutron activation analysis (NAA) and the experimental results were modelled with the HYDRAQL computer model. 9 refs.

  3. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

    International Nuclear Information System (INIS)

    Ouhadi, V.R.; Yong, R.N.; Shariatmadari, N.; Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M.

    2010-01-01

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO 3 ) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  4. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

    Energy Technology Data Exchange (ETDEWEB)

    Ouhadi, V.R., E-mail: vahidouhadi@yahoo.ca [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Yong, R.N. [RNY Geoenvironmental Research, North Saanich (Canada); Shariatmadari, N. [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M. [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2010-01-15

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO{sub 3}) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  5. Kaolinite-supported nanoscale zero-valent iron for removal of Pb2+ from aqueous solution: reactivity, characterization and mechanism.

    Science.gov (United States)

    Zhang, Xin; Lin, Shen; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2011-05-01

    The use of nanoscale zero-valent iron (nZVI) to remediate contaminated groundwater is limited due to its lack of durability and mechanical strength. To address this issue, 20% (w/w) nZVI was loaded onto kaolinite as a support material (K-nZVI). More than 96% of Pb(2+) was removed from aqueous solution using K-nZVI at an initial condition of 500 mg/L Pb(2+) within 30 min under the conditions of 10 g/L of K-nZVI, pH 5.10 and a temperature of 30 °C. To understand the mechanism of removal of Pb(2+), various techniques were implemented to characterize K-nZVI. Scanning electron microscopy (SEM) indicated that K-nZVI had a suitable dispersive state with a lower aggregation, where the mean specific surface area and average particle size as determined by the BET-N(2) method and X-ray diffraction (XRD), were 26.11 m(2)/g and 44.3 nm, respectively. The results obtained from XRD, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) indicated that a small number of iron oxides formed on the surface of K-nZVI, suggesting that free Pb(2+) was adsorbed onto K-nZVI and subsequently reduced to Pb(0). Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Highly efficient fluoride adsorption from aqueous solution by nepheline prepared from kaolinite through alkali-hydrothermal process.

    Science.gov (United States)

    Wang, Hao; Feng, Qiming; Liu, Kun; Li, Zishun; Tang, Xuekun; Li, Guangze

    2017-07-01

    A direct alkali-hydrothermal induced transformation process was adopted to prepare nepheline from raw kaolinite (shortened form RK in this paper) and NaOH solution in this paper. Structure and morphology characterizations of the synthetic product showed that the nepheline possessed high degree of crystallinity and uniform surface morphology. Specific surface area of nepheline is 18 m 2 /g, with a point of zero charge at around pH 5.0-5.5. The fluoride (F - ions) adsorption by the synthetic nepheline (shortened form SN in this paper) from aqueous solution was also investigated under different experimental conditions. The adsorption process well matched the Langmuir isotherm model with an amazing maximum adsorption capacity of 183 mg/g at 323 K. The thermodynamic parameters (ΔG 0 , ΔH 0 , and ΔS 0 ) for adsorption on SN were also determined from the temperature dependence. The adsorption capacities of fluoride on SN increased with increasing of temperature and initial concentration. Initial pH value also had influence on adsorption process. Adsorption of fluoride was rapidly increased in 5-60 min and thereafter increased slowly to reach the equilibrium in about 90-180 min under all conditions. The adsorption followed a pseudo-second order rate law. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Sensors properties of an alkylamine-intercalated kaolinite material towards the voltammetric preconcentration of [Ru(CN)6]4- at a clay-modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Tonle, I.K. [Ottawa Univ., ON (Canada). Dept. of Chemistry, Center for Catalysis Research and Innovation; Yanoude Univ. (Cameroon). Laboratoire de Chimie Analytique, Faculte des Sciences; Dschang Univ. (Cameroon). Dept. de Chimie; Bouwe, B.; Rose, G.; Ngameni, E. [Yanoude Univ. (Cameroon). Laboratoire de Chimie Analytique, Faculte des Sciences; Detellier, C. [Yanoude Univ. (Cameroon). Laboratoire de Chimie Analytique, Faculte des Sciences

    2008-07-01

    This study discussed the sensor properties of a kaolinite material in relation to the voltammetric preconcentration of ruthenium (Ru) anions in a clay-modified electrode. An organoclay was intercalated at room temperature with a layer of hexylamine. Dimethylsulfoxide (DMSO) was intercalated between the clay layers and displaced in wet conditions by the akylamine. The modified clay was then characterized using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The analyses confirmed the incorporation of the hexylamine between the kaolinite platelets. The organokaolinite was then studied for use as a preconcentration agent when coated on the active surface of a glassy carbon electrode for the accumulation of [Ru(CN)6]4- anions in a hydrochloric acid medium. Factors that influenced the conductivity of the film and the diffusion of the electroactive species within the film included the concentration of the electrolyte, and the redox probe. The study showed that kaolinite can be used as a material in electrochemical sensors.

  8. Polyacrylic acid grafted kaolinite via a facile ‘grafting to’ approach based on heterogeneous esterification and its adsorption for Cu2+

    Science.gov (United States)

    Zhao, Ping; Zhou, Qi; Yan, Chunjie; Luo, Wenjun

    2017-03-01

    Kaolinite (KLN) was successfully decorated by polyacrylic acid (PAA) brushes via a facile ‘one-step’ manner in this study. This process was achieved by heterogeneous esterification between carboxyl on the PAA chains and hydroxyl on the KLN in the presence of Al3+ as catalyst. The prepared composite (denoted as PAA-g-KLN) was characterized by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction pattern (XRD), Field emission scanning electron microscopy (FE-SEM) and thermogravimetry (TG) to confirm the successful grafting of PAA brushes on the surface of KLN. Subsequently, the PAA-g-KLN was used as adsorbent for the removal of Cu2+ from wastewater. Due to the introduction of abundant and highly accessible carboxyl groups on the surface of kaolinite, PAA-g-KLN exhibited an enhanced adsorption performance than raw kaolinite, which could be up to 32.45 mg·g-1 at 45 °C with a fast adsorption kinetic. Theoretical models analysis revealed that Langmuir isotherm model and the pseudo second-order model were more suitable for well elucidation of the experimental data. In addition, the regeneration experiment showed that the PAA-g-KLN could still keep a satisfactory adsorption capacity (>65%) by being reused for 6 consecutive cycles. The study provides an easy and rapid method for surface polyelectrolyte modification on inorganic mineral as a promising adsorbent to remove Cu2+ from aqueous solution.

  9. Application of Brazilian kaolinite clay as adsorbent to removal of U(VI) from aqueous solution: Kinetic and thermodynamic of cation-basic interactions

    Science.gov (United States)

    Guerra, Denis L.; Leidens, Victor L.; Viana, Rúbia R.; Airoldi, Claudio

    2010-05-01

    The compound N 1-[3-(trimethoxysilyl)propyl]diethylenetriamine was anchored onto Amazon kaolinite surface by heterogeneous route. The modified and natural kaolinite samples were characterized by transmission electron microscopy, scanning electron microscopic, X-ray diffraction, and nuclear magnetic nuclei of 29Si and 13C. The well-defined peaks obtained in the 13C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k2 values 16.0 and 25.1 mmol g -1 min -1 ranges for natural and modified kaolinite clays, respectively. The energetic effects caused by metal ion adsorption were determined through calorimetric titrations.

  10. A Typical Verification Challenge for the GRID

    NARCIS (Netherlands)

    van de Pol, Jan Cornelis; Bal, H. E.; Brim, L.; Leucker, M.

    2008-01-01

    A typical verification challenge for the GRID community is presented. The concrete challenge is to implement a simple recursive algorithm for finding the strongly connected components in a graph. The graph is typically stored in the collective memory of a number of computers, so a distributed

  11. Prediction and typicality in multiverse cosmology

    International Nuclear Information System (INIS)

    Azhar, Feraz

    2014-01-01

    In the absence of a fundamental theory that precisely predicts values for observable parameters, anthropic reasoning attempts to constrain probability distributions over those parameters in order to facilitate the extraction of testable predictions. The utility of this approach has been vigorously debated of late, particularly in light of theories that claim we live in a multiverse, where parameters may take differing values in regions lying outside our observable horizon. Within this cosmological framework, we investigate the efficacy of top-down anthropic reasoning based on the weak anthropic principle. We argue contrary to recent claims that it is not clear one can either dispense with notions of typicality altogether or presume typicality, in comparing resulting probability distributions with observations. We show in a concrete, top-down setting related to dark matter, that assumptions about typicality can dramatically affect predictions, thereby providing a guide to how errors in reasoning regarding typicality translate to errors in the assessment of predictive power. We conjecture that this dependence on typicality is an integral feature of anthropic reasoning in broader cosmological contexts, and argue in favour of the explicit inclusion of measures of typicality in schemes invoking anthropic reasoning, with a view to extracting predictions from multiverse scenarios. (paper)

  12. Prediction and typicality in multiverse cosmology

    Science.gov (United States)

    Azhar, Feraz

    2014-02-01

    In the absence of a fundamental theory that precisely predicts values for observable parameters, anthropic reasoning attempts to constrain probability distributions over those parameters in order to facilitate the extraction of testable predictions. The utility of this approach has been vigorously debated of late, particularly in light of theories that claim we live in a multiverse, where parameters may take differing values in regions lying outside our observable horizon. Within this cosmological framework, we investigate the efficacy of top-down anthropic reasoning based on the weak anthropic principle. We argue contrary to recent claims that it is not clear one can either dispense with notions of typicality altogether or presume typicality, in comparing resulting probability distributions with observations. We show in a concrete, top-down setting related to dark matter, that assumptions about typicality can dramatically affect predictions, thereby providing a guide to how errors in reasoning regarding typicality translate to errors in the assessment of predictive power. We conjecture that this dependence on typicality is an integral feature of anthropic reasoning in broader cosmological contexts, and argue in favour of the explicit inclusion of measures of typicality in schemes invoking anthropic reasoning, with a view to extracting predictions from multiverse scenarios.

  13. How typical are 'typical' tremor characteristics? : Sensitivity and specificity of five tremor phenomena

    NARCIS (Netherlands)

    van der Stouwe, A. M. M.; Elting, J. W.; van der Hoeven, J. H.; van Laar, T.; Leenders, K. L.; Maurits, N. M.; Tijssen, M. Aj.

    Introduction: Distinguishing between different tremor disorders can be challenging. Some tremor disorders are thought to have typical tremor characteristics: the current study aims to provide sensitivity and specificity for five 'typical' tremor phenomena. Methods: Retrospectively, we examined 210

  14. What is typical is good: The influence of face typicality on perceived trustworthiness

    NARCIS (Netherlands)

    Sofer, C.; Dotsch, R.; Wigboldus, D.H.J.; Todorov, A.T.

    2015-01-01

    The role of face typicality in face recognition is well established, but it is unclear whether face typicality is important for face evaluation. Prior studies have focused mainly on typicality's influence on attractiveness, although recent studies have cast doubt on its importance for attractiveness

  15. [Analysis of XRD spectral characteristics of soil clay mineral in two typical cultivated soils].

    Science.gov (United States)

    Zhang, Zhi-Dan; Luo, Xiang-Li; Jiang, Hai-Chao; Li, Qiao; Shen, Cong-Ying; Liu, Hang; Zhou, Ya-Juan; Zhao, Lan-Po; Wang, Ji-Hong

    2014-07-01

    The present paper took black soil and chernozem, the typical cultivated soil in major grain producing area of Northeast, as the study object, and determinated the soil particle composition characteristics of two cultivated soils under the same climate and location. Then XRD was used to study the composition and difference of clay mineral in two kinds of soil and the evolutionary mechanism was explored. The results showed that the two kinds of soil particles were composed mainly of the sand, followed by clay and silt. When the particle accumulation rate reached 50%, the central particle size was in the 15-130 microm interval. Except for black soil profile of Shengli Xiang, the content of clay showed converse sequence to the central particle in two soils. Clay accumulated under upper layer (18.82%) in black soil profile while under caliche layer (17.41%) in chernozem profile. Clay content was the least in parent material horizon except in black profile of Quanyanling. Analysis of clay XRD atlas showed that the difference lied in not only the strength of diffraction peak, but also in the mineral composition. The main contents of black soil and chernozem were both 2 : 1 clay, the composition of black soil was smectite/illite mixed layer-illite-vermiculite and that of chernozem was S/I mixture-illite-montmorillonite, and both of them contained little kaolinite, chlorite, quartz and other primary mineral. This paper used XRD to determine the characteristics of clay minerals comprehensively, and analyzed two kinds of typical cultivated soil comparatively, and it was a new perspective of soil minerals study.

  16. Thermodynamic and Kinetic Aspects of the Dissolution of Quartz-Kaolinite Mixtures by Alkalis Aspects thermodynamiques et cinétiques de la dissolution des mélanges quartz-kaolinite par les alcalis

    Directory of Open Access Journals (Sweden)

    Labrid J.

    2006-11-01

    'ensemble des données expérimentales indique que, outre l'adsorption de l'acide silicique Si(OH4 et de l'ion (***, il est nécessaire de faire appel à un autre mécanisme d'inhibition que l'on suppose joué par l'analcime adsorbée. Il est raisonnable de penser qu'avant précipitation, l'analcime est fixée sur la surface quartzeuse qui agit comme support à la nucléation. Ces hypothèses conduisent à un nouveau schéma cinétique qui inclut ces différents mécanismes d'adsorption. Les concentrations calculées en silicium et en aluminium solubilisés s'accordent bien aux données expérimentales pour des temps de réaction allant jusqu'à 3 000 heures. Les études faites sur la kaolinite ont montré que ce minéral est aussi capable d'adsorber l'aluminium, vraisemblablement sous la forme d'ion (***. Une procédure de traitement de l'argile est proposée en préalable à toute étude cinétique afin d'éliminer les espèces adsorbées. Dans ces conditions, la dissolution de la kaolinite est congruente. Par analogie avec la dissolution du quartz, et compte tenu de la structure minéralogique de la kaolinite, nous avons proposé un schéma cinétique de dissolution de l'argile qui décrit la co-adsorption des espèces Si(OH4 et (***, préalablement à la formation du cristal. La validité de ces mécanismes cinétiques a été examinée en menant des expériences de dissolution de mélanges de quartz et de kaolinite. La modélisation de l'attaque a été faite en prenant en compte les processus d'adsorption et de précipitation observés. Le modèle adopté qui traduit le couplage des processus élémentaires de dissolution permet le calcul des concentrations en aluminium et silicium solubilisés. La comparaison avec l'expérience indique qu'il est nécessaire d'attribuer à l'argile une réactivité notablement supérieure à celle déterminée avec le minéral isolé. Il est suggéré que le sable pourrait jouer un rôle sur l'état de dispersion de l'argile avec corr

  17. Typical horticultural products between tradition and innovation

    Directory of Open Access Journals (Sweden)

    Innocenza Chessa

    Full Text Available Recent EU and National policies for agriculture and rural development are mainly focused to foster the production of high quality products as a result of the increasing demand of food safety, typical foods and traditional processing methods. Another word very often used to describe foods in these days is “typicality” which pools together the concepts of “food connected with a specific place”, “historical memory and tradition” and “culture”. The importance for the EU and the National administrations of the above mentioned kind of food is demonstrated, among other things, by the high number of the PDO, PGI and TSG certificated products in Italy. In this period of global markets and economical crisis farmers are realizing how “typical products” can be an opportunity to maintain their market share and to improve the economy of local areas. At the same time, new tools and strategy are needed to reach these goals. A lack of knowledge has being recognized also on how new technologies and results coming from recent research can help in exploiting traditional product and in maintaining the biodiversity. Taking into account the great variety and richness of typical products, landscapes and biodiversity, this report will describe and analyze the relationships among typicality, innovation and research in horticulture. At the beginning “typicality” and “innovation” will be defined also through some statistical features, which ranks Italy at the first place in terms of number of typical labelled products, then will be highlighted how typical products of high quality and connected with the tradition and culture of specific production areas are in a strict relationship with the value of agro-biodiversity. Several different examples will be used to explain different successful methods and/or strategies used to exploit and foster typical Italian vegetables, fruits and flowers. Finally, as a conclusion, since it is thought that

  18. Identifying Typical Movements Among Indoor Objects

    DEFF Research Database (Denmark)

    Radaelli, Laura; Sabonis, Dovydas; Lu, Hua

    2013-01-01

    With the proliferation of mobile computing, positioning systems are becoming available that enable indoor location-based services. As a result, indoor tracking data is also becoming available. This paper puts focus on one use of such data, namely the identification of typical movement patterns...

  19. TYPICAL FORMS OF LIVER PATHOLOGY IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Peter F. Litvitskiy

    2018-01-01

    Full Text Available This lecture for the system of postgraduate medical education analyzes causes, types, key links of pathogenesis, and manifestations of the main typical forms of liver pathology — liver failure, hepatic coma, jaundice, cholemia, acholia, cholelithiasis, and their complications in children. To control the retention of the lecture material, case problems and multiple-choice tests are given.

  20. Typical electric bills, January 1, 1981

    International Nuclear Information System (INIS)

    1981-01-01

    The Typical Electric Bills report is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration; Department of Energy. The publication is geared to a variety of applications by electric utilities, industry, consumes, educational institutions, and government in recognition of the growing importance of energy planning in contemporary society. 19 figs., 18 tabs

  1. Unraveling climatic changes from intra-profile variation in oxygen and hydrogen isotopic composition of goethite and kaolinite in laterites: An integrated study from Yaou, French Guiana

    Science.gov (United States)

    Girard, Jean-Pierre; Freyssinet, Philippe; Chazot, Gilles

    2000-02-01

    An integrated study of O and H isotopes in the lateritic profile of Yaou, French Guiana, was undertaken to investigate the usefulness of stable isotopes as tracers of climatic changes in continental environments. The studied profile is composed of a 27 m thick saprolite, mostly developed in the past under wet-and-dry tropical climate in association with a duricrust, overlain by a 3 m thick yellow latosol formed more recently under present equatorial hot and humid climate. δ 18O-δD values determined for weathering goethite (pseudomorphs after pyrite) and kaolinite (microcrystalline clay groundmass) throughout the 30 m deep profile reflect formation temperatures consistent with present (25°C) and realistic past climatic temperatures (20°C-30°C), indicating that weathering minerals formed in isotopic equilibrium with their genetic environment and were not subjected to significant isotope exchange after formation. A distinct shift downward (2‰ for δ 18O, 15‰ for δD) from low to high δ 18O-δD values occurs around 20 m depth in the saprolite. It is interpreted as recording the change from the past tropical to the present equatorial climate. Goethite and kaolinite in the 5-10 m thick saprolite interval immediately above the active basement weathering front are in isotopic equilibrium with modern water and must have formed under present equatorial-humid conditions. In contrast, goethite and kaolinite found higher up in the saprolite and in the duricrust formed in the past under tropical wet and dry climate from waters distinctly depleted in 18O and D relative to modern water. The marked depletion of paleo-meteoric water at Yaou most likely reflects a more contrasted or "monsoonal" character of the ancient tropical climate. The present study shows that ancient weathering minerals in lateritic profiles preserve their δ 18O-δD values and carry a time signal. The time signal is best expressed in minerals formed rapidly at the weathering front and not subjected

  2. Unraveling climatic changes from intraprofile variation in oxygen and hydrogen isotopic composition of goethite and kaolinite in laterites: An integrated study from Yaou, French Guiana

    Energy Technology Data Exchange (ETDEWEB)

    Girard, J.P.; Freyssinet, P.; Chazot, G.

    2000-02-01

    An integrated study of O and H isotopes in the latertic profile of Yaou, French Guiana, was undertaken to investigate the usefulness of stable isotopes as tracers of climatic changes in continental environments. The studied profile is composed of a 27 m thick saprolite, mostly developed in the past under wet-and-dry tropical climate in association with a duricrust, overlain by a 3 m thick yellow latosol formed more recently under present equatorial hot and humid climate. {delta}{sup 18}O-{delta}D values determined for weathering goethite (pseudomorphs after pyrite) and kaolinite (microcrystalline clay groundmass) throughout the 30 m deep profile reflect formation temperatures consistent with present (25 C) and realistic past climatic temperatures (20 C--30 C), indicating that weathering minerals formed in isotopic equilibrium with their genetic environment and were not subjected to significant isotope exchange after formation. A distinct shift downward from low to high {delta}{sup 18}O-{delta}D values occurs around 20 m depth in the saprolite. It is interpreted as recording the change from the past tropical to the present equatorial climate. Goethite and kaolinite in the 5--10 m thick saprolite interval immediately above the active basement weathering front are in isotopic equilibrium with modern water and must have formed under present equatorial-humid conditions. In contrast, goethite and kaolinite found higher up on the saprolite and in the duricrust formed in the past under tropical wet and dry climate from waters distinctly depleted in {sup 18}O and D relative to modern water. The marked depletion of paleo-meteoric water at Yaou most likely reflects a more contrasted or monsoonal character of the ancient tropical climate. The present study shows that ancient weathering minerals in lateritic profiles preserve their {delta}{sup 18}O-{delta}D values and carry a time signal. The time signal is best expressed in minerals formed rapidly at the weathering front and

  3. Increase in Ice Nucleation Efficiency of Feldspars, Kaolinite and Mica in Dilute NH3 and NH4+-containing Solutions

    Science.gov (United States)

    Kumar, A.; Marcolli, C.; Luo, B.; Krieger, U. K.; Peter, T.

    2017-12-01

    Semivolatile species present in the atmosphere are prone to adhere to mineral dust particle surfaces during long range transport, and could potentially change the particle surface properties and its ice nucleation (IN) efficiency. Immersion freezing experiments were performed with microcline (K-feldspar), known to be highly IN active, suspended in aqueous solutions of ammonia, (NH4)2SO4, NH4HSO4, NH4NO3, NH4Cl, Na2SO4, H2SO4, K2SO4 and KCl to investigate the effect of solutes on the IN efficiency. Freezing of emulsified droplets investigated with a differential scanning calorimeter (DSC) showed that the heterogeneous ice nucleation temperatures deviate from the water activity-based IN theory, describing heterogeneous ice nucleation temperatures as a function of solution water activity by a constant offset with respect to the ice melting point curve (Zobrist et al. 2008). IN temperatures enhanced up to 4.5 K were observed for very dilute NH3 and NH4+-containing solutions while a decrease was observed as the concentration was further increased. For all solutes with cations other than NH4+, the IN efficiency decreased. An increase of the IN efficiency in very dilute NH3 and NH4+-containing solutions followed by a decrease with increasing concentration was also observed for sanidine (K-feldspar) and andesine (Na/Ca-feldspar). This is an important indication towards specific chemical interactions between solutes and the feldspar surface which is not captured by the water activity-based IN theory. A similar trend is present but less pronounced in case of kaolinite and mica, while quartz is barely affected. We hypothesize that the hydrogen bonding of NH3 molecules with surface -OH groups could be the reason for the enhanced freezing temperatures in dilute ammonia and ammonium containing solutions as they could form an ice-like overlayer providing hydrogen bonding groups for ice to nucleate on top of it. This implies to possibilities of enhanced IN efficiency, especially

  4. Herpes zoster - typical and atypical presentations.

    Science.gov (United States)

    Dayan, Roy Rafael; Peleg, Roni

    2017-08-01

    Varicella- zoster virus infection is an intriguing medical entity that involves many medical specialties including infectious diseases, immunology, dermatology, and neurology. It can affect patients from early childhood to old age. Its treatment requires expertise in pain management and psychological support. While varicella is caused by acute viremia, herpes zoster occurs after the dormant viral infection, involving the cranial nerve or sensory root ganglia, is re-activated and spreads orthodromically from the ganglion, via the sensory nerve root, to the innervated target tissue (skin, cornea, auditory canal, etc.). Typically, a single dermatome is involved, although two or three adjacent dermatomes may be affected. The lesions usually do not cross the midline. Herpes zoster can also present with unique or atypical clinical manifestations, such as glioma, zoster sine herpete and bilateral herpes zoster, which can be a challenging diagnosis even for experienced physicians. We discuss the epidemiology, pathophysiology, diagnosis and management of Herpes Zoster, typical and atypical presentations.

  5. Metabolic disorders with typical alterations in MRI

    International Nuclear Information System (INIS)

    Warmuth-Metz, M.

    2010-01-01

    The classification of metabolic disorders according to the etiology is not practical for neuroradiological purposes because the underlying defect does not uniformly transform into morphological characteristics. Therefore typical MR and clinical features of some easily identifiable metabolic disorders are presented. Canavan disease, Pelizaeus-Merzbacher disease, Alexander disease, X-chromosomal adrenoleukodystrophy and adrenomyeloneuropathy, mitochondrial disorders, such as MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) and Leigh syndrome as well as L-2-hydroxyglutaric aciduria are presented. (orig.) [de

  6. [Typical atrial flutter: Diagnosis and therapy].

    Science.gov (United States)

    Thomas, Dierk; Eckardt, Lars; Estner, Heidi L; Kuniss, Malte; Meyer, Christian; Neuberger, Hans-Ruprecht; Sommer, Philipp; Steven, Daniel; Voss, Frederik; Bonnemeier, Hendrik

    2016-03-01

    Typical, cavotricuspid-dependent atrial flutter is the most common atrial macroreentry tachycardia. The incidence of atrial flutter (typical and atypical forms) is age-dependent with 5/100,000 in patients less than 50 years and approximately 600/100,000 in subjects > 80 years of age. Concomitant heart failure or pulmonary disease further increases the risk of typical atrial flutter.Patients with atrial flutter may present with symptoms of palpitations, reduced exercise capacity, chest pain, or dyspnea. The risk of thromboembolism is probably similar to atrial fibrillation; therefore, the same antithrombotic prophylaxis is required in atrial flutter patients. Acutely symptomatic cases may be subjected to cardioversion or pharmacologic rate control to relieve symptoms. Catheter ablation of the cavotricuspid isthmus represents the primary choice in long-term therapy, associated with high procedural success (> 97 %) and low complication rates (0.5 %).This article represents the third part of a manuscript series designed to improve professional education in the field of cardiac electrophysiology. Mechanistic and clinical characteristics as well as management of isthmus-dependent atrial flutter are described in detail. Electrophysiological findings and catheter ablation of the arrhythmia are highlighted.

  7. Obtention of the cation exchange capacity of a natural kaolinite with radioactive tracers; Obtencion de la capacidad de intercambio cationico de una kaolinita natural con trazadores radioactivos

    Energy Technology Data Exchange (ETDEWEB)

    Uribe I, A.; Badillo A, V.E. [Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: Adrya81@hotmail.com

    2005-07-01

    One of the more used techniques for the elimination of the heavy metals present in water systems is to use adsorbent mineral phases like zeolites and clays, among others. The clays are able to exchange easily the fixed ions in the external surface of its crystals or well the ions present in the interlaminar spaces of the structures, for other existent ones in the encircling aqueous solutions for that the Cation exchange capacity (CIC) is defined as the sum of all the cations exchange that a mineral can possess independent to the physicochemical conditions. The CIC is equal to the measure of the total of negative charges of the mineral by mass of the solid (meq/g). In this investigation work, the value of the CIC equal to 2.5 meq/100 g is obtained, of a natural kaolinite from the State of Hidalgo studying the retention of the sodium in the kaolinite with the aid of the radioactive isotope {sup 24} Na and of the selective electrodes technique, making vary the pH value. So is experimentally demonstrated that the CIC is an intrinsic property of the mineral independent of the pH value of the solution and of the charges origin. (Author)

  8. Effects of network dissolution changes on pore-to-core upscaled reaction rates for kaolinite and anorthite reactions under acidic conditions

    KAUST Repository

    Kim, Daesang

    2013-11-01

    We have extended reactive flow simulation in pore-network models to include geometric changes in the medium from dissolution effects. These effects include changes in pore volume and reactive surface area, as well as topological changes that open new connections. The computed changes were based upon a mineral map from an X-ray computed tomography image of a sandstone core. We studied the effect of these changes on upscaled (pore-scale to core-scale) reaction rates and compared against the predictions of a continuum model. Specifically, we modeled anorthite and kaolinite reactions under acidic flow conditions during which the anorthite reactions remain far from equilibrium (dissolution only), while the kaolinite reactions can be near-equilibrium. Under dissolution changes, core-scale reaction rates continuously and nonlinearly evolved in time. At higher injection rates, agreement with predictions of the continuum model degraded significantly. For the far-from-equilibrium reaction, our results indicate that the ability to correctly capture the heterogeneity in dissolution changes in the reactive mineral surface area is critical to accurately predict upscaled reaction rates. For the near-equilibrium reaction, the ability to correctly capture the heterogeneity in the saturation state remains critical. Inclusion of a Nernst-Planck term to ensure neutral ionic currents under differential diffusion resulted in at most a 9% correction in upscaled rates.

  9. What Is Typical Is Good : The Influence of Face Typicality on Perceived Trustworthiness

    NARCIS (Netherlands)

    Sofer, Carmel; Dotsch, Ron; Wigboldus, Daniel H J; Todorov, Alexander

    2015-01-01

    The role of face typicality in face recognition is well established, but it is unclear whether face typicality is important for face evaluation. Prior studies have focused mainly on typicality’s influence on attractiveness, although recent studies have cast doubt on its importance for attractiveness

  10. Group typicality, group loyalty and cognitive development.

    Science.gov (United States)

    Patterson, Meagan M

    2014-09-01

    Over the course of childhood, children's thinking about social groups changes in a variety of ways. Developmental Subjective Group Dynamics (DSGD) theory emphasizes children's understanding of the importance of conforming to group norms. Abrams et al.'s study, which uses DSGD theory as a framework, demonstrates the social cognitive skills underlying young elementary school children's thinking about group norms. Future research on children's thinking about groups and group norms should explore additional elements of this topic, including aspects of typicality beyond loyalty. © 2014 The British Psychological Society.

  11. Modelling object typicality in description logics

    CSIR Research Space (South Africa)

    Britz, K

    2009-12-01

    Full Text Available in the context under consideration, than those lower down. For any given class C, we assume that all objects in the appli- cation domain that are in (the interpretation of) C are more typical of C than those not in C. This is a technical construction which... to be modular partial orders, i.e. reflexive, transitive, anti- symmetric relations such that, for all a, b, c in ∆I , if a and b are incomparable and a is strictly below c, then b is also strictly below c. Modular partial orders have the effect...

  12. Benchmark calculation programme concerning typical LMFBR structures

    International Nuclear Information System (INIS)

    Donea, J.; Ferrari, G.; Grossetie, J.C.; Terzaghi, A.

    1982-01-01

    This programme, which is part of a comprehensive activity aimed at resolving difficulties encountered in using design procedures based on ASME Code Case N-47, should allow to get confidence in computer codes which are supposed to provide a realistic prediction of the LMFBR component behaviour. The calculations started on static analysis of typical structures made of non linear materials stressed by cyclic loads. The fluid structure interaction analysis is also being considered. Reasons and details of the different benchmark calculations are described, results obtained are commented and future computational exercise indicated

  13. Typical skeletal changes due to metastasising neuroblastomas

    International Nuclear Information System (INIS)

    Eggerath, A.; Persigehl, M.; Mertens, R.; Technische Hochschule Aachen

    1983-01-01

    Compared with other solid tumours in childhood, neuroblastomas show a marked tendency to metastasise to the skeleton. The differentiation of these lesions from inflammatory and other malignant bone lesions in this age group is often difficult. The radiological findings in ten patients with metastasing and histologically confirmed neuroblastomas have been reviewed and the typical appearances in the skeleton are described. The most important features in the differential diagnosies are discussed and the significance of bone changes in the diagnosis of neuroblastoma have been evaluated. (orig.) [de

  14. The Typicality Ranking Task: A New Method to Derive Typicality Judgments from Children

    Science.gov (United States)

    Ameel, Eef; Storms, Gert

    2016-01-01

    An alternative method for deriving typicality judgments, applicable in young children that are not familiar with numerical values yet, is introduced, allowing researchers to study gradedness at younger ages in concept development. Contrary to the long tradition of using rating-based procedures to derive typicality judgments, we propose a method that is based on typicality ranking rather than rating, in which items are gradually sorted according to their typicality, and that requires a minimum of linguistic knowledge. The validity of the method is investigated and the method is compared to the traditional typicality rating measurement in a large empirical study with eight different semantic concepts. The results show that the typicality ranking task can be used to assess children’s category knowledge and to evaluate how this knowledge evolves over time. Contrary to earlier held assumptions in studies on typicality in young children, our results also show that preference is not so much a confounding variable to be avoided, but that both variables are often significantly correlated in older children and even in adults. PMID:27322371

  15. Combination of multi-scale and multi-edge X-ray spectroscopy for investigating the products obtained from the interaction between kaolinite and metallic iron in anoxic conditions at 90 °C

    Science.gov (United States)

    Rivard, Camille; Montargès-Pelletier, Emmanuelle; Vantelon, Delphine; Pelletier, Manuel; Karunakaran, Chithra; Michot, Laurent J.; Villieras, Frédéric; Michau, Nicolas

    2013-02-01

    In the context of radioactive waste repository in geological formation, kaolinite-metallic iron interaction in chlorine solution was conducted in batch experiments, under anoxic conditions at 90 °C during 9 months. After a mineralogical characterization at a global scale, products were analyzed at the micrometer and nanometer scales by X-ray absorption spectroscopic techniques (XAS and STXM). Absorption at Al, Si and Fe edges was investigated to have a complete overview of the distribution and status of constituting elements. Whereas Si K-edge results do not evidence significant evolution of silicon status, investigations at Al K-edge and Fe L-edges demonstrate variations at aggregate and particle scales of IVAl:VIAl and Fe2+:Fe3+ ratios. Spectroscopic data evidence the systematic crystallization of Fe-serpentines onto the remaining particles of kaolinite and the absence of pure species (kaolinite or Fe-serpentines). Combination of spatially resolved spectroscopic analyses and TEM-EDXS elemental distribution aims to calculate unit cell formulae of Fe-serpentines layers and abundance of each species in mixed particles. For most of the investigated particles, results reveal that the variations of particles composition are directly linked to the relative contributions of kaolinite and Fe-berthierine in mixed particles. However, for some particles, microscale investigations evidence crystallization of two other Fe-serpentines species, devoid of aluminum, cronstedtite and greenalite.

  16. ONE TYPICAL EXTREMUM IN ELECTRICAL PROBLEMS

    Directory of Open Access Journals (Sweden)

    V. I. Goroshko

    2014-01-01

    Full Text Available The aim of this work is to attract attention of teachers, scientific personnel, engineers and students to one peculiarity of extremum seeking in different electrical problems. This feature lies in the fact that in many parts of electrical engineering extremum seeking comes to analysis one and the same mathematical structure (T-structure, but differences lie only in many symbols (designation.In one problems this structure appear in finale, the most simple form, but in others – T-structure is “veiled”, and as a rule  we need  elementary algebraic transformation to detect it.Taking into account high frequency of this structure appearing in electrical problems, in the first part of article the authors  carried out the investigation of extremum characteristics of T-structure and show the results in easy algorithms. To determine the typical T-structure there were taken five problems-examples for extremum seeking  from different parts of electrical engineering. The first and the second examples belong to the theory of electrical circuits.In the first example the problem of maximum active load power obtaining was considered, in the second we see the solution of problem for inductive coupled circuit adjustment in order to obtain the hump current. In the third example the band active filter, built on operating amplifier, is analyzed. According to these methods, taken in the first part of article, the frequency is determined, on which amplifier provides maximum  amplification factor. The forth example deals with analysis of efficiency of transformer. According to algorithm, the optimal efficiency of transformer’s load and also equation for its maximum was determined in this article. In the fifth example the mechanical characteristics of induction motor is analyzed. It is indicated how, on the basis of algorithms article, to obtain equations for critical slip and motor moment, and also the simple development of formula Klossa.The methods of

  17. Adsorption of Cs+, Ni2+ and lanthanides onto a kaolinite and Na-montmorillonite up to 1500C: an experimental and modeling study

    International Nuclear Information System (INIS)

    Tertre, E.

    2005-10-01

    The motivation for this study is to assess the temperature effect on the clay minerals sorption properties. Sorption and desorption of Cs + , Ni 2+ et Ln 3+ onto a montmorillonite and a kaolinite were performed by batch experiments between 25 and 150 C, and in different pH and ionic strengths conditions. Sorption enthalpies varying between 0 and 80 kJ/mol were then calculated. For europium, surface spectroscopic analyses confirmed that the mechanism involved is adsorption, including at 150 C. Moreover, this method allowed us to obtain qualitatively the different adsorption equilibrium occurring during the reaction. An acid/base study of the clay surfaces was performed in order to assess the temperature effect on the surface charge of these minerals. Then, a surface complexation model including edge sites and structural sites was proposed to interpret the acid/base data and the europium sorption data. (author)

  18. Typical and atypical presentations of aspergilloma

    International Nuclear Information System (INIS)

    Villajos, M.; Darnell, A.; Gallardo, X.; Castaner, E.; Mata, J. M.; Paedavila, E.

    1999-01-01

    To show the different forms of radiological presentations of aspergilloma, emphasizing the importance of recognizing the atypical forms. The explorations of 11 patients with aspergilloma were examined retrospectively between 1993 and 1997. These patients were studied using conventional X-rays and computed tomography (CT): Typical and atypical radiological findings were observed. In two patients, who presented recurrent hemoptysis, a percutaneous installation of amphotericin B was carried out with tomographic control. Out of the 11 patients, two were female and nine male. In eight of the cases the radiological findings showed an intercavity injury with different evolutionary forms, while in three of the cases there was a progressive pleural swelling. In the two patients treated pertinaciously, no significant radiological changes were observed, however, neither of them showed hemoptysis again. The pleural swelling adjacent to the cavity and/or the swelling of the cavity wall are atypical radiological presentations of the aspergilloma, that can accompany or precede the appearance of this illness. (Author) 7 refs

  19. Idiopathic intracranial hypertension: A typical presentation

    International Nuclear Information System (INIS)

    Algahtani, Hussein A.; Obeid, Tahir H.; Abuzinadah, Ahmad R.; Baeesa, Saleh S.

    2007-01-01

    Objective was to describe the clinical features of 5 patients with rare atypical presentation of idiopathic intracranial hypertension (IIH), and propose the possible mechanism of this atypical presentation. We carried out a retrospective study of 5 patients, admitted at King Khalid National Guard Hospital, Jeddah, Kingdom of Saudi Arabia with IIH during the period from January 2001 to December 2005. All were females with their age ranges from 24 to 40 years. The clinical presentations, the laboratory and imaging studies were analyzed. The opening pressures of the lumbar puncture tests were documented. All patients were presented with headache. One had typical pain of trigeminal neuralgia and one with neck pain and radiculopathy. Facial diplegia was present in one patient and two patients had bilateral 6th cranial neuropathy. Papilledema was present in all patients except in one patient. Imaging study was normal in all patients, and they had a very high opening pressure during lumbar puncture, except in one patient. All patients achieved full recovery with medical therapy in 6 to 12 weeks with no relapse during the mean follow up of 2 years. Atypical finding in IIH are rare and require a high index of suspicion for early diagnosis. (author)

  20. TYPICAL ABSENCES: RESULTS OF OWN INVESTIGATIONS

    Directory of Open Access Journals (Sweden)

    K. Yu. Mukhin

    2015-01-01

    Full Text Available Typical absences (TA are brief primary generalized epileptic seizures characterized by sudden onset and termination. According to their definition, absences consist of impairment of consciousness that is synchronously accompanied by electroencephalographic (EEG changes as generalized spike–slow wave discharges of 3 or more Hz. The authors conducted an investigation of 1261 patients with different forms of epilepsy with onset of seizures from the first days of life to the age of 18 years. The patients were followed up from 1990 to 2010. Absence seizures were detected in 231 patients, which accounts for 18.3 % of all the epileptic patients. TA were found in 102 patients, which constitutes 8.1 % of all cases of epilepsy with onset of seizures beyond the age of 18 years. The paper provides a detailed analysis of a group of patients with TA in terms of anamnestic, clinical, electroencephalographic, and neuroimaging features and the results of therapy with antiepileptic drugs (AEDs. The age of onset of TA-associated epilepsy was from 9 months to 17 years (mean 9.4 ± 4.06 years. The disease occurred most frequently in young school-age children (41.2 %. Isolated TA as the only type of seizures were observed in the clinical picture of 28 (27.5 % patients. TA were concurrent with other types of seizures in other cases. The investigators have identified 4 types of seizures which TA (generalized convulsions, myoclonic seizures, febrile seizures, and eyelid myoclonia may be concurrent with. Neuroimaging stated there were no brain changes in 85.3 % of TA-associated epilepsy cases. Moderate diffuse subatrophic changes were detected in other cases (14.7 %. Local cerebral structural abnormalities were absent. The use of antiepileptic therapy as both monotherapy and polytherapy using different combinations showed the high efficacy of AEDs. Complete remission was achieved in 84.3 % of TA-associated epilepsy cases. An AED-induced reduction in the frequency of

  1. Risperidone versus typical antipsychotic medication for schizophrenia.

    Science.gov (United States)

    Hunter, R H; Joy, C B; Kennedy, E; Gilbody, S M; Song, F

    2003-01-01

    found in long-term studies (n=859, 2RCTs RR not 20% improved 0.51 CI 0.38 to 0.67 NNT 4;n=675 1RCT, RR not improved 40% 0.75 CI 0.66 to 0.84 NNT 5; n=675, 1 RCT, RR not 60% improved 0.90 CI 0.84 to 0.96, NNT 11). Risperidone was also more likely to reduce relapse at one year follow up, compared with haloperidol (n=367, 1 RCT, RR 0.64 CI 0.41 to 0.99, NNT 7). Less people allocated risperidone left studies before completion, both for short-term (n=3066, 16 RCTs, RR 0.76 CI 0.63 to 0.92, NNT 6) and long-term trials (n=1270, 4RCTs, RR 0.55 CI 0.42 to 0.73 NNT 4). For general movement disorders results favoured risperidone. People given risperidone had significantly fewer general movement disorders (including extrapyramidal side effects) than those receiving older typical antipsychotics (n=2702, 10 RCTs, RR 0.63 CI 0.56 to 0.71, NNT 3). Significantly fewer people given risperidone used antiparkinsonian drugs (n=2524, 11 RCTs, RR 0.66 CI 0.58 to 0.74, NNT 4). As regards body weight, however, four studies (n=1708) found people were more likely to gain weight if allocated risperidone compared to typical antipsychotics (RR 1.55 CI 1.25 to 1.93, NNH 3). Risperidone was no more or less likely than haloperidol to cause sexual problems such as erectile dysfunction (n=106, 2 RCTs, RR 1.55 CI 0.58 to 4.20). Finally, some results found risperidone was more likely to cause rhinitis than conventional antipsychotics (n=656, 3 RCTs, RR1.99 CI 1.24 to 3.19, NNH 3). Risperidone may be more acceptable to those with schizophrenia than older antipsychotics and have marginal benefits in terms of limited clinical improvement. Its adverse effect profile may be better than haloperidol. With the addition of more studies to this review, the publication bias evident in previous versions is no longer a significant issue. Any marginal benefits this drug may have have to be balanced against its greater cost and increased tendency to cause side effects such as weight gain. Recent important longer term

  2. Sorption of cobalt in zeolites and natural clays of the clinoptilolite and kaolinite type; Sorcion de cobalto en zeolitas y arcillas naturales del tipo clinoptilolita y caolinita

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, J.I.; Solache R, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In this work the sorption of cobalt of aqueous solutions in two natural zeolites (clinoptilolite) and a clay (kaolinite) of origin in the center-north region of Mexico is evaluated. The effect of the pH and the time of contact in the process of sorption were evaluated. The cobalt retained in the aluminosilicates was determined by neutron activation analysis. The cobalt sorption in the materials in a range of pH from 4 to 7 does not present significant variations. The studies of reaction kinetics show a very fast sorption in the first 5 hours of contact, reaching the equilibrium in approximately 24 hours. The kinetics of sorption of the cobalt ions was represented better by the Ritchie reaction model modified of second order. The experimental data for the zeolites obtained at ambient temperature and varying the concentration were adjusted to the models of Freundlich, Langmuir and Freundlich-Langmuir isotherms and it was observed that the cobalt sorption it behaves according to the Freundlich isotherm model. (Author)

  3. Characterization of bentonite, fibrous and kaolinite clays with regard to their use in pelotherapy; Caracterizacion de bentonitas, arcillas fibrosas y arcillas caoliniferas para su empleo en peloterapia

    Energy Technology Data Exchange (ETDEWEB)

    Pozo Martin, E.; Martin Rubi, J. A.; Pozo Rodriguez, M.

    2011-07-01

    We have characterized the mineralogical and chemical contents of several Spanish special clays (bentonite, fibrous clays and kaolin). Mineralogical analyses revealed that the samples were composed mainly of phyllosilicates (78 %-99 %) with a notable presence of dioctahedral and trioctahedral smectites in the bentonite, kaolinite in the kaolin and sepiolite or palygorskite in the fibrous clays. Illite was the common subordinate mineral in the bentonite, kaolin and palygorskite. Quartz, calcite, dolomite and feldspars were found as associate minerals with the occasional presence of zeolites and amphiboles. The chemical analysis was consistent with the mineralogy. With regard to trace elements (V, Cr, Ni, Co, Cu, Zn, As, Mo, Ba, Sb, Pb, U), the whole samples of the magnesium bentonite and sepiolite were found to have the lowest trace-element contents (<257,28 ppm ), whilst the aluminium bentonite, kaolin and particularly the palygorskite had higher contents than the other clays, with some elements occasionally exceeding the contents of previously studied common clays. Nevertheless, all the trace elements were found in lower quantities than the recommended toxicity levels and those quantities currently used in pelotherapy in Spanish spas. (Author)

  4. Adsorption of Cs{sup +}, Ni{sup 2+} and lanthanides onto a kaolinite and Na-montmorillonite up to 150{sup 0}C: an experimental and modeling study; Adsorption de Cs{sup +}, Ni{sup 2+} et des lanthanides sur une kaolinite et une smectite jusqu'a 150{sup 0}C: etude experimentale et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Tertre, E

    2005-10-15

    The motivation for this study is to assess the temperature effect on the clay minerals sorption properties. Sorption and desorption of Cs{sup +}, Ni{sup 2+} et Ln{sup 3+} onto a montmorillonite and a kaolinite were performed by batch experiments between 25 and 150 C, and in different pH and ionic strengths conditions. Sorption enthalpies varying between 0 and 80 kJ/mol were then calculated. For europium, surface spectroscopic analyses confirmed that the mechanism involved is adsorption, including at 150 C. Moreover, this method allowed us to obtain qualitatively the different adsorption equilibrium occurring during the reaction. An acid/base study of the clay surfaces was performed in order to assess the temperature effect on the surface charge of these minerals. Then, a surface complexation model including edge sites and structural sites was proposed to interpret the acid/base data and the europium sorption data. (author)

  5. Impact of an Alkaline Solution on the Chemistry, Mineralogy, and Sorption Properties of a Typic Rhodudult Soil

    Directory of Open Access Journals (Sweden)

    Jaqueline Alves de Almeida Calábria

    2017-11-01

    Full Text Available Abstract The preferred option for disposal of short-lived low and intermediate level radioactive wastes is a near surface disposal facility in which soil is one of the barriers that avoid radionuclide migration outside the controlled area. For construction of that kind of facility, concrete is widely used, and its interaction with water induces its degradation, resulting in a high pH solution. The alkaline solution may affect the near-field environment of radioactive waste repositories, including the soil, promoting mineralogical alterations that result in significant changes in key properties of materials, compromising their performance as safety components. In this study, a sample of a Brazilian Typic Rhodudult soil, previously investigated concerning its performance for Cs sorption, was subjected to interaction with the alkaline solution for 24 h and for 7, 14, and 28 days in order to evaluate the impact on its chemical, mineralogical, and sorption properties. X-ray diffraction (XRD, energy dispersive X-ray spectroscopy (EDX, atomic absorption spectrometry (AAS, scanning electron microscopy (SEM, and electron microprobe analysis were performed before and after each alteration period. Results indicated dissolution of minerals, such as kaolinite and quartz, associated with incorporation of K and Ca from the alkaline solution, likely resulting in the formation of hydrated calcium silicate phases (CSH, which are expected to be worse sorbents for alkaline elements (e.g., Cs than the original minerals. The Kd values for Cs in the altered samples also decreased according to the alteration period, demonstrating that alkaline interaction effectively modifies the soil sorption properties for Cs.

  6. Kaolinite, illite and quartz dissolution in the karstification of Paleozoic sandstones of the Furnas Formation, Paraná Basin, Southern Brazil

    Science.gov (United States)

    Melo, Mário Sérgio de; Guimarães, Gilson Burigo; Chinelatto, Adilson Luiz; Giannini, Paulo César Fonseca; Pontes, Henrique Simão; Chinelatto, Adriana Scoton Antonio; Atencio, Daniel

    2015-11-01

    Karstification processes in sandstones of the Furnas Formation, Silurian to Devonian of the Paraná Basin, have been described since the mid-twentieth century. However, some geologists still doubt the idea of true karst in sandstones. Studies carried out in the Campos Gerais region, Paraná State, Southern Brazil, aimed at investigating the nature of erosion processes in Furnas Formation and the role of the dissolution in the development of their notorious erosive features and underground cavities. These studies have led to the recognition of dissolution macro to micro features ('furnas', caves, ponds, sinks, ruiniform relief on cliffs and rocky surfaces, grain corrosion, speleothems, mineral reprecipitation and incrustation). The analysis (scanning electron microscopy, energy dispersive spectrometry and x-ray diffractometry) of sandstones and their alterites has indicated significant dissolution of clay cement along with discrete quartz grain dissolution. This mesodiagenetic cement (kaolinite and illite) is dissolved and reprecipitated as clay minerals with poorly developed crystallinity along with other minerals, such as variscite and minerals of the alunite supergroup, suggesting organic participation in the processes of dissolution and incrustation. The mineral reprecipitation usually forms centimetric speleothems, found in cavities and sheltered rocky surfaces. The cement dissolution associated with other factors (fractures, wet weather, strong hydraulic gradient, antiquity of the landforms) leads to the rock arenisation, the underground erosion and the appearance of the karst features. Carbonate rocks in the basement may locally be increasing the karst forms in the overlying Furnas Formation. The recognition of the karst character of the Furnas Formation sandstones has important implications in the management of underground water resources (increasingly exploited in the region), in the use of the unique geological heritage and in the prevention of geo

  7. Foods Inducing Typical Gastroesophageal Reflux Disease Symptoms in Korea

    OpenAIRE

    Choe, Jung Wan; Joo, Moon Kyung; Kim, Hyo Jung; Lee, Beom Jae; Kim, Ji Hoon; Yeon, Jong Eun; Park, Jong-Jae; Kim, Jae Seon; Byun, Kwan Soo; Bak, Young-Tae

    2017-01-01

    Background/Aims Several specific foods are known to precipitate gastroesophageal reflux disease (GERD) symptoms and GERD patients are usually advised to avoid such foods. However, foods consumed daily are quite variable according to regions, cultures, etc. This study was done to elucidate the food items which induce typical GERD symptoms in Korean patients. Methods One hundred and twenty-six Korean patients with weekly typical GERD symptoms were asked to mark all food items that induced typic...

  8. Concept typicality responses in the semantic memory network.

    Science.gov (United States)

    Santi, Andrea; Raposo, Ana; Frade, Sofia; Marques, J Frederico

    2016-12-01

    For decades concept typicality has been recognized as critical to structuring conceptual knowledge, but only recently has typicality been applied in better understanding the processes engaged by the neurological network underlying semantic memory. This previous work has focused on one region within the network - the Anterior Temporal Lobe (ATL). The ATL responds negatively to concept typicality (i.e., the more atypical the item, the greater the activation in the ATL). To better understand the role of typicality in the entire network, we ran an fMRI study using a category verification task in which concept typicality was manipulated parametrically. We argue that typicality is relevant to both amodal feature integration centers as well as category-specific regions. Both the Inferior Frontal Gyrus (IFG) and ATL demonstrated a negative correlation with typicality, whereas inferior parietal regions showed positive effects. We interpret this in light of functional theories of these regions. Interactions between category and typicality were not observed in regions classically recognized as category-specific, thus, providing an argument against category specific regions, at least with fMRI. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 12 CFR 408.6 - Typical classes of action.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Typical classes of action. 408.6 Section 408.6 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES PROCEDURES FOR COMPLIANCE WITH THE NATIONAL ENVIRONMENTAL POLICY ACT Eximbank Implementing Procedures § 408.6 Typical classes of action. (a) Section 1507.3...

  10. Narrative versus style: Effect of genre-typical events versus genre-typical filmic realizations on film viewers’ genre recognition

    NARCIS (Netherlands)

    Visch, V.; Tan, E.

    2008-01-01

    This study investigated whether film viewers recognize four basic genres (comic, drama, action and nonfiction) on the basis of genre-typical event cues or of genre-typical filmic realization cues of events. Event cues are similar to the narrative content of a film sequence, while filmic realization

  11. Generation of typical meteorological year for different climates of China

    International Nuclear Information System (INIS)

    Jiang, Yingni

    2010-01-01

    Accurate prediction of building energy performance requires precise information of the local climate. Typical weather year files like typical meteorological year (TMY) are commonly used in building simulation. They are also essential for numerical analysis of sustainable and renewable energy systems. The present paper presents the generation of typical meteorological year (TMY) for eight typical cities representing the major climate zones of China. The data set, which includes global solar radiation data and other meteorological parameters referring to dry bulb temperature, relative humidity, wind speed, has been analyzed. The typical meteorological year is generated from the available meteorological data recorded during the period 1995-2004, using the Finkelstein-Schafer statistical method. The cumulative distribution function (CDF) for each year is compared with the CDF for the long-term composite of all the years in the period. Typical months for each of the 12 calendar months from the period of years are selected by choosing the one with the smallest deviation from the long-term CDF. The 12 typical months selected from the different years are used for the formulation of a TMY.

  12. South American Youth and Integration : Typical Situations and Youth ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    South American Youth and Integration : Typical Situations and Youth ... IDRC partner the World Economic Forum is building a hub for inclusive growth ... Brazil, Paraguay and Uruguay) and their perception of rights, democracy and regional.

  13. Portion distortion: typical portion sizes selected by young adults.

    Science.gov (United States)

    Schwartz, Jaime; Byrd-Bredbenner, Carol

    2006-09-01

    The incidence of obesity has increased in parallel with increasing portion sizes of individually packaged and ready-to-eat prepared foods as well as foods served at restaurants. Portion distortion (perceiving large portion sizes as appropriate amounts to eat at a single eating occasion) may contribute to increasing energy intakes and expanding waistlines. The purpose of this study was to determine typical portion sizes that young adults select, how typical portion sizes compare with reference portion sizes (based in this study on the Nutrition Labeling and Education Act's quantities of food customarily eaten per eating occasion), and whether the size of typical portions has changed over time. Young adults (n=177, 75% female, age range 16 to 26 years) at a major northeastern university. Participants served themselves typical portion sizes of eight foods at breakfast (n=63) or six foods at lunch or dinner (n=62, n=52, respectively). Typical portion-size selections were unobtrusively weighed. A unit score was calculated by awarding 1 point for each food with a typical portion size that was within 25% larger or smaller than the reference portion; larger or smaller portions were given 0 points. Thus, each participant's unit score could range from 0 to 8 at breakfast or 0 to 6 at lunch and dinner. Analysis of variance or t tests were used to determine whether typical and reference portion sizes differed, and whether typical portion sizes changed over time. Mean unit scores (+/-standard deviation) were 3.63+/-1.27 and 1.89+/-1.14, for breakfast and lunch/dinner, respectively, indicating little agreement between typical and reference portion sizes. Typical portions sizes in this study tended to be significantly different from those selected by young adults in a similar study conducted 2 decades ago. Portion distortion seems to affect the portion sizes selected by young adults for some foods. This phenomenon has the potential to hinder weight loss, weight maintenance, and

  14. Effects of stress typicality during speeded grammatical classification.

    Science.gov (United States)

    Arciuli, Joanne; Cupples, Linda

    2003-01-01

    The experiments reported here were designed to investigate the influence of stress typicality during speeded grammatical classification of disyllabic English words by native and non-native speakers. Trochaic nouns and iambic gram verbs were considered to be typically stressed, whereas iambic nouns and trochaic verbs were considered to be atypically stressed. Experiments 1a and 2a showed that while native speakers classified typically stressed words individual more quickly and more accurately than atypically stressed words during differences reading, there were no overall effects during classification of spoken stimuli. However, a subgroup of native speakers with high error rates did show a significant effect during classification of spoken stimuli. Experiments 1b and 2b showed that non-native speakers classified typically stressed words more quickly and more accurately than atypically stressed words during reading. Typically stressed words were classified more accurately than atypically stressed words when the stimuli were spoken. Importantly, there was a significant relationship between error rates, vocabulary size and the size of the stress typicality effect in each experiment. We conclude that participants use information about lexical stress to help them distinguish between disyllabic nouns and verbs during speeded grammatical classification. This is especially so for individuals with a limited vocabulary who lack other knowledge (e.g., semantic knowledge) about the differences between these grammatical categories.

  15. Toddlers' categorization of typical and scrambled dolls and cars.

    Science.gov (United States)

    Heron, Michelle; Slaughter, Virginia

    2008-09-01

    Previous research has demonstrated discrimination of scrambled from typical human body shapes at 15-18 months of age [Slaughter, V., & Heron, M. (2004). Origins and early development of human body knowledge. Monographs of the Society for Research in Child Development, 69]. In the current study 18-, 24- and 30-month-old infants were presented with four typical and four scrambled dolls in a sequential touching procedure, to assess the development of explicit categorization of human body shapes. Infants were also presented with typical and scrambled cars, allowing comparison of infants' categorization of scrambled and typical exemplars in a different domain. Spontaneous comments regarding category membership were recorded. Girls categorized dolls and cars as typical or scrambled at 30 months, whereas boys only categorized the cars. Earliest categorization was for typical and scrambled cars, at 24 months, but only for boys. Language-based knowledge, coded from infants' comments, followed the same pattern. This suggests that human body knowledge does not have privileged status in infancy. Gender differences in performance are discussed.

  16. Food and Wine Tourism: an Analysis of Italian Typical Products

    Directory of Open Access Journals (Sweden)

    Francesco Maria Olivieri

    2015-06-01

    Full Text Available The aim of this work is to focus the specific role of local food productions in spite of its relationship with tourism sector to valorization and promotion of the territorial cultural heritage. The modern agriculture has been and, in the recent years, several specific features are emerging referring to different territorials areas. Tourist would like to have a complete experience consumption of a destination, specifically to natural and cultural heritage and genuine food. This contribute addresses the topics connected to the relationship between typical productions system and tourism sector to underline the competitive advantages to local development. The typical productions are Designation of Protected Origin (Italian DOP, within wine certifications DOCG and DOC and Typical Geographical Indication (IGP and wine’s IGT. The aim is an analysis of the specialization of these kinds of production at Italian regional scale. The implication of the work has connected with defining a necessary and appropriate value strategies based on marketing principles in order to translate the benefit of typical productions to additional value for the local system. Thus, the final part of the paper describes the potential dynamics with the suitable accommodation typology of agriturismo and the typical production system of Italian Administrative Regions.

  17. Early Freezing of Gait: Atypical versus Typical Parkinson Disorders

    Directory of Open Access Journals (Sweden)

    Abraham Lieberman

    2015-01-01

    Full Text Available In 18 months, 850 patients were referred to Muhammad Ali Parkinson Center (MAPC. Among them, 810 patients had typical Parkinson disease (PD and 212 had PD for ≤5 years. Among the 212 patients with early PD, 27 (12.7% had freezing of gait (FOG. Forty of the 850 had atypical parkinsonism. Among these 40 patients, all of whom had symptoms for ≤5 years, 12 (30.0% had FOG. FOG improved with levodopa in 21/27 patients with typical PD but did not improve in the 12 patients with atypical parkinsonism. FOG was associated with falls in both groups of patients. We believe that FOG unresponsive to levodopa in typical PD resembles FOG in atypical parkinsonism. We thus compared the 6 typical PD patients with FOG unresponsive to levodopa plus the 12 patients with atypical parkinsonism with the 21 patients with typical PD responsive to levodopa. We compared them by tests of locomotion and postural stability. Among the patients with FOG unresponsive to levodopa, postural stability was more impaired than locomotion. This finding leads us to believe that, in these patients, postural stability, not locomotion, is the principal problem underlying FOG.

  18. Generation of a typical meteorological year for Hong Kong

    International Nuclear Information System (INIS)

    Chan, Apple L.S.; Chow, T.T.; Fong, Square K.F.; Lin, John Z.

    2006-01-01

    Weather data can vary significantly from year to year. There is a need to derive typical meteorological year (TMY) data to represent the long-term typical weather condition over a year, which is one of the crucial factors for successful building energy simulation. In this paper, various types of typical weather data sets including the TMY, TMY2, WYEC, WYEC2, WYEC2W, WYEC2T and IWEC were reviewed. The Finkelstein-Schafer statistical method was applied to analyze the hourly measured weather data of a 25-year period (1979-2003) in Hong Kong and select representative typical meteorological months (TMMs). The cumulative distribution function (CDF) for each year was compared with the CDF for the long-term composite of all the years in the period for four major weather indices including dry bulb temperature, dew point temperature, wind speed and solar radiation. Typical months for each of the 12 calendar months from the period of years were selected by choosing the one with the smallest deviation from the long-term CDF. The 12 TMMs selected from the different years were used for formulation of a TMY for Hong Kong

  19. Spatial Resolution of the ECE for JET Typical Parameters

    International Nuclear Information System (INIS)

    Tribaldos, V.

    2000-01-01

    The purpose of this report is to obtain estimations of the spatial resolution of the electron cyclotron emission (ECE) phenomena for the typical plasmas found in JET tokamak. The analysis of the spatial resolution of the ECE is based on the underlying physical process of emission and a working definition is presented and discussed. In making these estimations a typical JET pulse is being analysed taking into account the magnetic configuration, the density and temperature profiles, obtained with the EFIT code and from the LIDAR diagnostic. Ray tracing simulations are performed for a Maxwellian plasma taking into account the antenna pattern. (Author) 5 refs

  20. Typicality effects in artificial categories: is there a hemisphere difference?

    Science.gov (United States)

    Richards, L G; Chiarello, C

    1990-07-01

    In category classification tasks, typicality effects are usually found: accuracy and reaction time depend upon distance from a prototype. In this study, subjects learned either verbal or nonverbal dot pattern categories, followed by a lateralized classification task. Comparable typicality effects were found in both reaction time and accuracy across visual fields for both verbal and nonverbal categories. Both hemispheres appeared to use a similarity-to-prototype matching strategy in classification. This indicates that merely having a verbal label does not differentiate classification in the two hemispheres.

  1. Determination of illuminants representing typical white light emitting diodes sources

    DEFF Research Database (Denmark)

    Jost, S.; Ngo, M.; Ferrero, A.

    2017-01-01

    is to develop LED-based illuminants that describe typical white LED products based on their Spectral Power Distributions (SPDs). Some of these new illuminants will be recommended in the update of the CIE publication 15 on colorimetry with the other typical illuminants, and among them, some could be used......Solid-state lighting (SSL) products are already in use by consumers and are rapidly gaining the lighting market. Especially, white Light Emitting Diode (LED) sources are replacing banned incandescent lamps and other lighting technologies in most general lighting applications. The aim of this work...... to complement the CIE standard illuminant A for calibration use in photometry....

  2. Modeling of the non isothermal and non isobaric transformations kinetics. Application to the kaolinite de-hydroxylation and to the tri-uranium octo-oxide reduction by hydrogen; Modelisation de la cinetique de transformations non isothermes et (ou) non isobares. Application a la deshydroxylation de la kaolinite et a la reduction de l'octooxyde de triuranium par l'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, St

    2002-12-15

    The aim of this work is to be able to describe transformations, occurring when solids and gases are in non isothermal and non isobaric conditions, with kinetic models. A methodology has been used. Two essential processes have to be taken into account: the germination and the growth. The germs are supposed to be formed (at constant temperature and pressure) in the grains surface with a constant velocity by surface unit, (gamma), called germination surface frequency (number of germs.m{sup -2}.s{sup -1}. The growth velocity is characterized by a growth surface reactivity, (phi) (in mol.m{sup -2}.s{sup -1}). With an appropriate transformation model, it is possible to obtain the variations of (gamma) and (phi) in terms of the temperature and pressure which are then used in the calculation of the velocity in non isothermal and non isobaric conditions. In order to validate the developed method, two reactions have been studied. For the first one, the kaolinite de-hydroxylation, an anisotropic germination-growth model, where the step limiting the growth is a diffusion step, has been developed in order to explain the experimental kinetic curves. Nevertheless the velocity curves calculated from this model do not allow to describe the reaction for some temperature variations. This result shows the difficulty to precisely determine the germination surface frequency what induces an important approximation on the kinetic curves. The second reaction is the tri-uranium octo-oxide reduction by hydrogen. It has been shown that this reaction occurs according to three successive transformations. A kinetic model has been developed for each of these reactions considering germination as instantaneous. At last, in comparing this model with the experimental velocity curves, a very good agreement has been verified as well as for a temperature variation than for a hydrogen partial pressure change during the reaction. (O.M.)

  3. Face-to-Face Interference in Typical and Atypical Development

    Science.gov (United States)

    Riby, Deborah M.; Doherty-Sneddon, Gwyneth; Whittle, Lisa

    2012-01-01

    Visual communication cues facilitate interpersonal communication. It is important that we look at faces to retrieve and subsequently process such cues. It is also important that we sometimes look away from faces as they increase cognitive load that may interfere with online processing. Indeed, when typically developing individuals hold face gaze…

  4. Gendered Perceptions of Typical Engineers across Specialties for Engineering Majors

    Science.gov (United States)

    Kelley, Margaret S.; Bryan, Kimberley K.

    2018-01-01

    Young women do not choose to be engineers nearly as often as young men, and they tend to cluster in particular specialties when they do. We examine these patterns and the role of gender schemas as applied to perceptions of typical engineers in understanding the choices that women make in terms of engineering specialties. We use Part 1 of two waves…

  5. The Roots of Disillusioned American Dream in Typical American

    Institute of Scientific and Technical Information of China (English)

    古冬华

    2016-01-01

    Typical American is one of Gish Jen’s notable novels catching attention of the American literary circle. The motif of disillusioned American dream can be seen clearly through the experiences of three main characters. From perspectives of the consumer culture and cultural conflicts, this paper analyzes the roots of the disillusioned American dream in the novel.

  6. Analogical Reasoning Ability in Autistic and Typically Developing Children

    Science.gov (United States)

    Morsanyi, Kinga; Holyoak, Keith J.

    2010-01-01

    Recent studies (e.g. Dawson et al., 2007) have reported that autistic people perform in the normal range on the Raven Progressive Matrices test, a formal reasoning test that requires integration of relations as well as the ability to infer rules and form high-level abstractions. Here we compared autistic and typically developing children, matched…

  7. Breast Metastases from Extramammary Malignancies: Typical and Atypical Ultrasound Features

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Sung Hee [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Department of Radiology, Catholic University of Daegu College of Medicine, Daegu 712-702 (Korea, Republic of); Ko, Eun Young; Han, Boo-Kyung; Shin, Jung Hee [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, Suk Jung [Department of Radiology, Inje University College of Medicine, Busan Paik Hospital, Busan 614-735 (Korea, Republic of); Cho, Eun Yoon [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)

    2014-07-01

    Breast metastases from extramammary malignancies are uncommon. The most common sources are lymphomas/leukemias and melanomas. Some of the less common sources include carcinomas of the lung, ovary, and stomach, and infrequently, carcinoid tumors, hypernephromas, carcinomas of the liver, tonsil, pleura, pancreas, cervix, perineum, endometrium and bladder. Breast metastases from extramammary malignancies have both hematogenous and lymphatic routes. According to their routes, there are common radiological features of metastatic diseases of the breast, but the features are not specific for metastases. Typical ultrasound (US) features of hematogenous metastases include single or multiple, round to oval shaped, well-circumscribed hypoechoic masses without spiculations, calcifications, or architectural distortion; these masses are commonly located superficially in subcutaneous tissue or immediately adjacent to the breast parenchyma that is relatively rich in blood supply. Typical US features of lymphatic breast metastases include diffusely and heterogeneously increased echogenicities in subcutaneous fat and glandular tissue and a thick trabecular pattern with secondary skin thickening, lymphedema, and lymph node enlargement. However, lesions show variable US features in some cases, and differentiation of these lesions from primary breast cancer or from benign lesions is difficult. In this review, we demonstrate various US appearances of breast metastases from extramammary malignancies as typical and atypical features, based on the results of US and other imaging studies performed at our institution. Awareness of the typical and atypical imaging features of these lesions may be helpful to diagnose metastatic lesions of the breast.

  8. Physico-chemical properties and fertility status of some typic ...

    African Journals Online (AJOL)

    Physico-chemical properties and fertility status of some typic plinthaquults in bauchi loval government area of Bauchi state, Nigeria. S Mustapha. Abstract. No Abstract. IJOTAFS Vol. 1 (2) 2007: pp. 120-124. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  9. Spectra of conditionalization and typicality in the multiverse

    Science.gov (United States)

    Azhar, Feraz

    2016-02-01

    An approach to testing theories describing a multiverse, that has gained interest of late, involves comparing theory-generated probability distributions over observables with their experimentally measured values. It is likely that such distributions, were we indeed able to calculate them unambiguously, will assign low probabilities to any such experimental measurements. An alternative to thereby rejecting these theories, is to conditionalize the distributions involved by restricting attention to domains of the multiverse in which we might arise. In order to elicit a crisp prediction, however, one needs to make a further assumption about how typical we are of the chosen domains. In this paper, we investigate interactions between the spectra of available assumptions regarding both conditionalization and typicality, and draw out the effects of these interactions in a concrete setting; namely, on predictions of the total number of species that contribute significantly to dark matter. In particular, for each conditionalization scheme studied, we analyze how correlations between densities of different dark matter species affect the prediction, and explicate the effects of assumptions regarding typicality. We find that the effects of correlations can depend on the conditionalization scheme, and that in each case atypicality can significantly change the prediction. In doing so, we demonstrate the existence of overlaps in the predictions of different "frameworks" consisting of conjunctions of theory, conditionalization scheme and typicality assumption. This conclusion highlights the acute challenges involved in using such tests to identify a preferred framework that aims to describe our observational situation in a multiverse.

  10. 7 CFR 632.52 - Identifying typical classes of action.

    Science.gov (United States)

    2010-01-01

    ... § 632.52 Identifying typical classes of action. (a) The RFO will analyze the environmental assessment of....12. These actions are determined by a limited environmental assessment that reasonably identifies the... 632.52 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES...

  11. Characteristics of typical Pierce guns for PPM focused TWTs

    International Nuclear Information System (INIS)

    Harper, R.; Puri, M.P.

    1989-01-01

    The performance of typical moderate perveance Pierce type electron guns which are used in periodic permanent magnet focused traveling wave tubes are described with regard to adaptation for use in electron beam ion sources. The results of detailed electron trajectory computations for one particular gun design are presented

  12. Human Behavior, Learning, and the Developing Brain: Typical Development

    Science.gov (United States)

    Coch, Donna, Ed.; Fischer, Kurt W., Ed.; Dawson, Geraldine, Ed.

    2010-01-01

    This volume brings together leading authorities from multiple disciplines to examine the relationship between brain development and behavior in typically developing children. Presented are innovative cross-sectional and longitudinal studies that shed light on brain-behavior connections in infancy and toddlerhood through adolescence. Chapters…

  13. Breast Metastases from Extramammary Malignancies: Typical and Atypical Ultrasound Features

    International Nuclear Information System (INIS)

    Mun, Sung Hee; Ko, Eun Young; Han, Boo-Kyung; Shin, Jung Hee; Kim, Suk Jung; Cho, Eun Yoon

    2014-01-01

    Breast metastases from extramammary malignancies are uncommon. The most common sources are lymphomas/leukemias and melanomas. Some of the less common sources include carcinomas of the lung, ovary, and stomach, and infrequently, carcinoid tumors, hypernephromas, carcinomas of the liver, tonsil, pleura, pancreas, cervix, perineum, endometrium and bladder. Breast metastases from extramammary malignancies have both hematogenous and lymphatic routes. According to their routes, there are common radiological features of metastatic diseases of the breast, but the features are not specific for metastases. Typical ultrasound (US) features of hematogenous metastases include single or multiple, round to oval shaped, well-circumscribed hypoechoic masses without spiculations, calcifications, or architectural distortion; these masses are commonly located superficially in subcutaneous tissue or immediately adjacent to the breast parenchyma that is relatively rich in blood supply. Typical US features of lymphatic breast metastases include diffusely and heterogeneously increased echogenicities in subcutaneous fat and glandular tissue and a thick trabecular pattern with secondary skin thickening, lymphedema, and lymph node enlargement. However, lesions show variable US features in some cases, and differentiation of these lesions from primary breast cancer or from benign lesions is difficult. In this review, we demonstrate various US appearances of breast metastases from extramammary malignancies as typical and atypical features, based on the results of US and other imaging studies performed at our institution. Awareness of the typical and atypical imaging features of these lesions may be helpful to diagnose metastatic lesions of the breast

  14. Typical School Day Experiences of Indian Children in Different Contexts.

    Science.gov (United States)

    Jaya, N.; Malar, G.

    2003-01-01

    Notes that India has experienced conditions that have lead to significant illiteracy, but that commitment to education can be found in lesser-known parts of India today. Profiles three schools in Tamil Nadu and describes a typical school day for a student with special needs, a student in a tribal setting, and a student in a rural setting. (TJQ)

  15. Typical and Atypical Dementia Family Caregivers: Systematic and Objective Comparisons

    Science.gov (United States)

    Nichols, Linda O.; Martindale-Adams, Jennifer; Burns, Robert; Graney, Marshall J.; Zuber, Jeffrey

    2011-01-01

    This systematic, objective comparison of typical (spouse, children) and atypical (in-law, sibling, nephew/niece, grandchild) dementia family caregivers examined demographic, caregiving and clinical variables. Analysis was of 1,476 caregivers, of whom 125 were atypical, from the Resources for Enhancing Alzheimer's Caregivers Health (REACH I and II)…

  16. Typical load shapes for six categories of Swedish commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Noren, C.

    1997-01-01

    In co-operation with several Swedish electricity suppliers, typical load shapes have been developed for six categories of commercial buildings located in the south of Sweden. The categories included in the study are: hotels, warehouses/grocery stores, schools with no kitchen, schools with kitchen, office buildings, health, health buildings. Load shapes are developed for different mean daily outdoor temperatures and for different day types, normally standard weekdays and standard weekends. The load shapes are presented as non-dimensional normalized 1-hour load. All measured loads for an object are divided by the object`s mean load during the measuring period and typical load shapes are developed for each category of buildings. Thus errors were kept lower as compared to use of W/m{sup 2}-terms. Typical daytime (9 a.m. - 5 p.m.) standard deviations are 7-10% of the mean values for standard weekdays but during very cold or warm weather conditions, single objects can deviate from the typical load shape. On weekends, errors are higher and depending on very different activity levels in the buildings, it is difficult to develop weekend load shapes with good accuracy. The method presented is very easy to use for similar studies and no building simulation programs are needed. If more load data is available, a good method to lower the errors is to make sure that every category only consists of objects with the same activity level, both on weekdays and weekends. To make it easier to use the load shapes, Excel load shape workbooks have been developed, where it is even possible to compare typical load shapes with measured data. 23 refs, 53 figs, 20 tabs

  17. Narrative versus Style : Effect of Genre Typical Events versus Genre Typical Filmic Realizations on Film Viewers' Genre Recognition

    NARCIS (Netherlands)

    Visch, V.; Tan, E.

    2008-01-01

    This study investigated whether film viewers recognize four basic genres (comic, drama, action and nonfiction) on the basis of genre-typical event cues or of genretypical filmic realization cues of events. Event cues are similar to the narrative content of a film sequence, while filmic realization

  18. SSI response of a typical shear wall structure

    International Nuclear Information System (INIS)

    Johnson, J.J.; Maslenikov, O.R.; Schewe, E.C.

    1985-01-01

    The seismic response of a typical shear structure in a commercial nuclear power plant was investigated for a series of site and foundation conditions using best estimate and design procedures. The structure selected is a part of the Zion AFT complex which is a connected group of reinforced concrete shear wall buildings, typical of nuclear power plant structures. Comparisons between best estimate responses quantified the effects of placing the structure on different sites and founding it in different manners. Calibration factors were developed by comparing simplified SSI design procedure responses to responses calculated by best estimate procedures. Nineteen basic cases were analyzed - each case was analyzed for ten earthquakes targeted to the NRC R.G. 1.60 design response spectra. The structure is a part of the Zion auxiliary-fuel handling turbine building (AFT) complex to the Zion nuclear power plants. (orig./HP)

  19. Analysis of typical meteorological years in different climates of China

    International Nuclear Information System (INIS)

    Yang, Liu; Lam, Joseph C.; Liu, Jiaping

    2007-01-01

    Typical meteorological years (TMYs) for 60 cities in the five major climatic zones (severe cold, cold, hot summer and cold winter, hot summer and warm winter, mild) in China were investigated. Long term (1971-2000) measured weather data such as dry bulb and dew point temperatures, wind speed and global solar radiation were gathered and analysed. A total of seven climatic indices were used to select the 12 typical meteorological months (TMMs) that made up the TMY for each city. In general, the cumulative distribution functions of the TMMs selected tended to follow their long term counterparts quite well. There was no persistent trend in any particular years being more representative than the others, though 1978 and 1982 tended to be picked most often. This paper presents the work and its findings. Future work on the assessment of TMYs in building energy simulation is also discussed

  20. Memory for radio advertisements: the effect of program and typicality.

    Science.gov (United States)

    Martín-Luengo, Beatriz; Luna, Karlos; Migueles, Malen

    2013-01-01

    We examined the influence of the type of radio program on the memory for radio advertisements. We also investigated the role in memory of the typicality (high or low) of the elements of the products advertised. Participants listened to three types of programs (interesting, boring, enjoyable) with two advertisements embedded in each. After completing a filler task, the participants performed a true/false recognition test. Hits and false alarm rates were higher for the interesting and enjoyable programs than for the boring one. There were also more hits and false alarms for the high-typicality elements. The response criterion for the advertisements embedded in the boring program was stricter than for the advertisements in other types of programs. We conclude that the type of program in which an advertisement is inserted and the nature of the elements of the advertisement affect both the number of hits and false alarms and the response criterion, but not the accuracy of the memory.

  1. Verbal communication skills in typical language development: a case series.

    Science.gov (United States)

    Abe, Camila Mayumi; Bretanha, Andreza Carolina; Bozza, Amanda; Ferraro, Gyovanna Junya Klinke; Lopes-Herrera, Simone Aparecida

    2013-01-01

    The aim of the current study was to investigate verbal communication skills in children with typical language development and ages between 6 and 8 years. Participants were 10 children of both genders in this age range without language alterations. A 30-minute video of each child's interaction with an adult (father and/or mother) was recorded, fully transcribed, and analyzed by two trained researchers in order to determine reliability. The recordings were analyzed according to a protocol that categorizes verbal communicative abilities, including dialogic, regulatory, narrative-discursive, and non-interactive skills. The frequency of use of each category of verbal communicative ability was analyzed (in percentage) for each subject. All subjects used more dialogical and regulatory skills, followed by narrative-discursive and non-interactive skills. This suggests that children in this age range are committed to continue dialog, which shows that children with typical language development have more dialogic interactions during spontaneous interactions with a familiar adult.

  2. Monte Carlo based radial shield design of typical PWR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gul, Anas; Khan, Rustam; Qureshi, M. Ayub; Azeem, Muhammad Waqar; Raza, S.A. [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan). Dept. of Nuclear Engineering; Stummer, Thomas [Technische Univ. Wien (Austria). Atominst.

    2017-04-15

    This paper presents the radiation shielding model of a typical PWR (CNPP-II) at Chashma, Pakistan. The model was developed using Monte Carlo N Particle code [2], equipped with ENDF/B-VI continuous energy cross section libraries. This model was applied to calculate the neutron and gamma flux and dose rates in the radial direction at core mid plane. The simulated results were compared with the reference results of Shanghai Nuclear Engineering Research and Design Institute (SNERDI).

  3. Typical event horizons in AdS/CFT

    Energy Technology Data Exchange (ETDEWEB)

    Avery, Steven G.; Lowe, David A. [Department of Physics, Brown University,Providence, RI 02912 (United States)

    2016-01-14

    We consider the construction of local bulk operators in a black hole background dual to a pure state in conformal field theory. The properties of these operators in a microcanonical ensemble are studied. It has been argued in the literature that typical states in such an ensemble contain firewalls, or otherwise singular horizons. We argue this conclusion can be avoided with a proper definition of the interior operators.

  4. Typical event horizons in AdS/CFT

    Science.gov (United States)

    Avery, Steven G.; Lowe, David A.

    2016-01-01

    We consider the construction of local bulk operators in a black hole background dual to a pure state in conformal field theory. The properties of these operators in a microcanonical ensemble are studied. It has been argued in the literature that typical states in such an ensemble contain firewalls, or otherwise singular horizons. We argue this conclusion can be avoided with a proper definition of the interior operators.

  5. Lipoma arborescens: Comparison of typical and atypical disease presentations

    International Nuclear Information System (INIS)

    Howe, B.M.; Wenger, D.E.

    2013-01-01

    Aim: To determine whether the aetiology differed between typical cases of lipoma arborescens with unilateral knee involvement and atypical cases involving joints other than the knee, polyarticular disease, and disease outside of the knee joint. Materials and methods: Cases of lipoma arborescens involving the knee joint were evaluated for the distribution of the disease and severity of degenerative arthritis. Joints other than the knee were evaluated for the presence and severity of degenerative arthritis, and the distribution was classified as either intra-articular, extra-articular, or both. Clinical history was reviewed for patient age at presentation, a history of inflammatory arthritis, diabetes mellitus, and known steroid use. Fisher's exact test was used to determine whether there was a statistically significant difference between typical and atypical presentations of the disease. Results: Lipoma arborescens was identified in 45 joints in 39 patients. Twenty-eight patients were classified as “typical” and 11 patients had “atypical” disease. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. Conclusion: Twenty-eight percent of patients in the present study had atypical presentation of lipoma arborescens with multifocal lipoma arborescens or disease in joints other than the knee. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. Of the 39 patients, only three had no evidence of degenerative arthritis, which suggests that many cases of lipoma arborescens are secondary to chronic reactive change in association with degenerative arthritis

  6. Theory of Mind experience sampling in typical adults.

    Science.gov (United States)

    Bryant, Lauren; Coffey, Anna; Povinelli, Daniel J; Pruett, John R

    2013-09-01

    We explored the frequency with which typical adults make Theory of Mind (ToM) attributions, and under what circumstances these attributions occur. We used an experience sampling method to query 30 typical adults about their everyday thoughts. Participants carried a Personal Data Assistant (PDA) that prompted them to categorize their thoughts as Action, Mental State, or Miscellaneous at approximately 30 pseudo-random times during a continuous 10-h period. Additionally, participants noted the direction of their thought (self versus other) and degree of socializing (with people versus alone) at the time of inquiry. We were interested in the relative frequency of ToM (mental state attributions) and how prominent they were in immediate social exchanges. Analyses of multiple choice answers suggest that typical adults: (1) spend more time thinking about actions than mental states and miscellaneous things, (2) exhibit a higher degree of own- versus other-directed thought when alone, and (3) make mental state attributions more frequently when not interacting (offline) than while interacting with others (online). A significant 3-way interaction between thought type, direction of thought, and socializing emerged because action but not mental state thoughts about others occurred more frequently when participants were interacting with people versus when alone; whereas there was an increase in the frequency of both action and mental state attributions about the self when participants were alone as opposed to socializing. A secondary analysis of coded free text responses supports findings 1-3. The results of this study help to create a more naturalistic picture of ToM use in everyday life and the method shows promise for future study of typical and atypical thought processes. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Analysis and Comparison of Typical Models within Distribution Network Design

    DEFF Research Database (Denmark)

    Jørgensen, Hans Jacob; Larsen, Allan; Madsen, Oli B.G.

    This paper investigates the characteristics of typical optimisation models within Distribution Network Design. During the paper fourteen models known from the literature will be thoroughly analysed. Through this analysis a schematic approach to categorisation of distribution network design models...... for educational purposes. Furthermore, the paper can be seen as a practical introduction to network design modelling as well as a being an art manual or recipe when constructing such a model....

  8. Rural Tourism and Local Development: Typical Productions of Lazio

    Directory of Open Access Journals (Sweden)

    Francesco Maria Olivieri

    2014-12-01

    Full Text Available The local development is based on the integration of the tourism sector with the whole economy. The rural tourism seems to be a good occasion to analyse the local development: consumption of "tourist products" located in specific local contexts. Starting from the food and wine supply chain and the localization of typical productions, the aim of the present work will be analyse the relationship with local development, rural tourism sustainability and accommodation system, referring to Lazio. Which are the findings to create tourism local system based on the relationship with touristic and food and wine supply chain? Italian tourism is based on accommodation system, so the whole consideration of the Italian cultural tourism: tourism made in Italy. The touristic added value to specific local context takes advantage from the synergy with food and wine supply chain: made in Italy of typical productions. Agritourism could be better accommodation typology to rural tourism and to exclusivity of consumption typical productions. The reciprocity among food and wine supply chain and tourism provides new insights on the key topics related to tourism development and to the organization of geographical space as well and considering its important contribution nowadays to the economic competitiveness.

  9. Typically Female Features in Hungarian Shopping Tourism

    Directory of Open Access Journals (Sweden)

    Gábor Michalkó

    2006-06-01

    Full Text Available Although shopping has been long acknowledged as a major tourist activity, the extent and characteristics of shopping tourism have only recently become the subject of academic research and discussion. As a contribution to this field of knowledge, the paper presents the characteristics of shopping tourism in Hungary, and discusses the typically female features of outbound Hungarian shopping tourism. The research is based on a survey of 2473 Hungarian tourists carried out in 2005. As the findings of the study indicate, while female respondents were altogether more likely to be involved in tourist shopping than male travellers, no significant difference was experienced between the genders concerning the share of shopping expenses compared to their total travel budget. In their shopping behaviour, women were typically affected by price levels, and they proved to be both more selfish and more altruistic than men by purchasing more products for themselves and for their family members. The most significant differences between men and women were found in their product preferences as female tourists were more likely to purchase typically feminine goods such as clothes, shoes, bags and accessories, in the timing of shopping activities while abroad, and in the information sources used by tourists, since interpersonal influences such as friends’, guides’ and fellow travellers’ recommendations played a higher role in female travellers’ decisions.

  10. Transformações mineralógicas e cristaloquímicas decorrentes dos ensaios termais em argilas cauliníticas ferruginosas Mineralogical and crystalochemical transformations originated from thermal essays on ferruginous kaolinitic clays

    Directory of Open Access Journals (Sweden)

    M. M. Ferreira

    2012-03-01

    Full Text Available Transformações mineralógicas e cristaloquímicas foram investigadas em amostras de argilas cauliníticas ferruginosas aquecidas a temperaturas de 800, 1000 e 1200 °C. As análises de difração de raios X e térmica diferencial e gravimétrica mostraram ser a caulinita o argilomineral predominante nas amostras naturais. Os resultados da espectroscopia Mössbauer mostraram que o alto conteúdo em Fe (22,5% em peso, determinado por fluorescência de raios X, é relacionado à presença de goethita (18% em peso e hematita (16% em peso. Entretanto um resíduo deste elemento (Fe3+ e Fe2+ foi constatado após a extração do ferro usando solução de ditionito-citrato-bicarbonato, e possivelmente se deve à presença de ferro na estrutura da caulinita. O processo de sinterização mostra uma desestruturação da caulinita, assim como a transformação da goethita em hematita, cujo tamanho dos cristais cresce com o incremento da temperatura. O tamanho do cristal de hematita a 1200 °C é 5 vezes maior do que na amostra natural. A mulita formada a 1000 °C é constituída da solução sólida de Fe2O3, com Al2O3, o que resulta em produto resistente e de maior estabilidade térmica.Mineralogical and crystallochemical transformations of representative ferruginous kaolinitic clay samples were investigated in specimens burned at 800, 1000 and 1200 °C. X-ray diffraction and differential thermal and thermogravimetric analyses showed that kaolinite was the predominant mineral in the raw samples. The Mössbauer spectroscopy results showed that the high iron content (22.5 wt.%, as determined by X-ray fluorescence, is related to the presence of goethite (18 wt.% and hematite (16 wt.%. However, after Fe was extracted using a dithionite-citrate system buffered with sodium bicarbonate, a residue of this element (Fe3+ and Fe2+ was found in the structure of the kaolinite. The sintering process showed the destruction of kaolinite, as well as the transformation of

  11. Narrative versus Style: Effect of Genre Typical Events versus Genre Typical Filmic Realizations on Film Viewers' Genre Recognition

    OpenAIRE

    Visch, V.; Tan, E.

    2008-01-01

    This study investigated whether film viewers recognize four basic genres (comic, drama, action and nonfiction) on the basis of genre-typical event cues or of genretypical filmic realization cues of events. Event cues are similar to the narrative content of a film sequence, while filmic realization cues are similar to stylistic surface cues of a film sequence. It was predicted that genre recognition of short film fragments is cued more by filmic realization cues than by event cues. The results...

  12. Dysphonia Severity Index in Typically Developing Indian Children.

    Science.gov (United States)

    Pebbili, Gopi Kishore; Kidwai, Juhi; Shabnam, Srushti

    2017-01-01

    Dysphonia is a variation in an individual's quality, pitch, or loudness from the voice characteristics typical of a speaker of similar age, gender, cultural background, and geographic location. Dysphonia Severity Index (DSI) is a recognized assessment tool based on a weighted combination of maximum phonation time, highest frequency, lowest intensity, and jitter (%) of an individual. Although dysphonia in adults is accurately evaluated using DSI, standard reference values for school-age children have not been studied. This study aims to document the DSI scores in typically developing children (8-12 years). A total of 42 typically developing children (8-12 years) without complaint of voice problem on the day of testing participated in the study. DSI was computed by substituting the raw scores of substituent parameters: maximum phonation time, highest frequency, lowest intensity, and jitter% using various modules of CSL 4500 software. The average DSI values obtained in children were 2.9 (1.23) and 3.8 (1.29) for males and females, respectively. DSI values are found to be significantly higher (P = 0.027) for females than those for males in Indian children. This could be attributed to the anatomical and behavioral differences among females and males. Further, pubertal changes set in earlier for females approximating an adult-like physiology, thereby leading to higher DSI values in them. The mean DSI value obtained for male and female Indian children can be used as a preliminary reference data against which the DSI values of school-age children with dysphonia can be compared. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  13. A generalized window energy rating system for typical office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Cheng; Chen, Tingyao; Yang, Hongxing; Chung, Tse-ming [Research Center for Building Environmental Engineering, Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong (China)

    2010-07-15

    Detailed computer simulation programs require lengthy inputs, and cannot directly provide an insight to relationship between the window energy performance and the key window design parameters. Hence, several window energy rating systems (WERS) for residential houses and small buildings have been developed in different countries. Many studies showed that utilization of daylight through elaborate design and operation of windows leads to significant energy savings in both cooling and lighting in office buildings. However, the current WERSs do not consider daylighting effect, while most of daylighting analyses do not take into account the influence of convective and infiltration heat gains. Therefore, a generalized WERS for typical office buildings has been presented, which takes all primary influence factors into account. The model includes embodied and operation energy uses and savings by a window to fully reflect interactions among the influence parameters. Reference locations selected for artificial lighting and glare control in the current common simulation practice may cause uncompromised conflicts, which could result in over- or under-estimated energy performance. Widely used computer programs, DOE2 and ADELINE, for hourly daylighting and cooling simulations have their own weaknesses, which may result in unrealistic or inaccurate results. An approach is also presented for taking the advantages of the both programs and avoiding their weaknesses. The model and approach have been applied to a typical office building of Hong Kong as an example to demonstrate how a WERS in a particular location can be established and how well the model can work. The energy effect of window properties, window-to-wall ratio (WWR), building orientation and lighting control strategies have been analyzed, and can be indicated by the localized WERS. An application example also demonstrates that the algebraic WERS derived from simulation results can be easily used for the optimal design of

  14. Benefit and cost curves for typical pollination mutualisms.

    Science.gov (United States)

    Morris, William F; Vázquez, Diego P; Chacoff, Natacha P

    2010-05-01

    Mutualisms provide benefits to interacting species, but they also involve costs. If costs come to exceed benefits as population density or the frequency of encounters between species increases, the interaction will no longer be mutualistic. Thus curves that represent benefits and costs as functions of interaction frequency are important tools for predicting when a mutualism will tip over into antagonism. Currently, most of what we know about benefit and cost curves in pollination mutualisms comes from highly specialized pollinating seed-consumer mutualisms, such as the yucca moth-yucca interaction. There, benefits to female reproduction saturate as the number of visits to a flower increases (because the amount of pollen needed to fertilize all the flower's ovules is finite), but costs continue to increase (because pollinator offspring consume developing seeds), leading to a peak in seed production at an intermediate number of visits. But for most plant-pollinator mutualisms, costs to the plant are more subtle than consumption of seeds, and how such costs scale with interaction frequency remains largely unknown. Here, we present reasonable benefit and cost curves that are appropriate for typical pollinator-plant interactions, and we show how they can result in a wide diversity of relationships between net benefit (benefit minus cost) and interaction frequency. We then use maximum-likelihood methods to fit net-benefit curves to measures of female reproductive success for three typical pollination mutualisms from two continents, and for each system we chose the most parsimonious model using information-criterion statistics. We discuss the implications of the shape of the net-benefit curve for the ecology and evolution of plant-pollinator mutualisms, as well as the challenges that lie ahead for disentangling the underlying benefit and cost curves for typical pollination mutualisms.

  15. SSI response of a typical shear wall structure. Volume 1

    International Nuclear Information System (INIS)

    Johnson, J.J.; Schewe, E.C.; Maslenikov, O.R.

    1984-04-01

    The Simplified Methods project of the US NRC-funded Seismic Safety Margins Research Program (SSMRP) has as its goal the development of a methodology to perform routine seismic probabilistic risk assessments of commercial nuclear power plants. The study reported here develops calibration factors to relate best estimate response to design values accounting for approximations and simplifications in SSI analysis procedures. Nineteen cases were analyzed and in-structure response compared. The structure of interest was a typical shear wall structure. 6 references, 44 figures, 22 tables

  16. Typical exposure of children to EMF: exposimetry and dosimetry

    International Nuclear Information System (INIS)

    Valic, Blaz; Kos, Bor; Gajsek, Peter

    2015-01-01

    A survey study with portable exposimeters, worn by 21 children under the age of 17, and detailed measurements in an apartment above a transformer substation were carried out to determine the typical individual exposure of children to extremely low- and radio-frequency (RF) electromagnetic field. In total, portable exposimeters were worn for >2400 h. Based on the typical individual exposure the in situ electric field and specific absorption rate (SAR) values were calculated for an 11-y-old female human model. The average exposure was determined to be low compared with ICNIRP reference levels: 0.29 μT for an extremely low frequency (ELF) magnetic field and 0.09 V m -1 for GSM base stations, 0.11 V m -1 for DECT and 0.10 V m -1 for WiFi; other contributions could be neglected. However, some of the volunteers were more exposed: the highest realistic exposure, to which children could be exposed for a prolonged period of time, was 1.35 μT for ELF magnetic field and 0.38 V m -1 for DECT, 0.13 V m -1 for WiFi and 0.26 V m -1 for GSM base stations. Numerical calculations of the in situ electric field and SAR values for the typical and the worst-case situation show that, compared with ICNIRP basic restrictions, the average exposure is low. In the typical exposure scenario, the extremely low frequency exposure is <0.03 % and the RF exposure <0.001 % of the corresponding basic restriction. In the worst-case situation, the extremely low frequency exposure is <0.11 % and the RF exposure <0.007 % of the corresponding basic restrictions. Analysis of the exposures and the individual's perception of being exposed/ unexposed to an ELF magnetic field showed that it is impossible to estimate the individual exposure to an ELF magnetic field based only on the information provided by the individuals, as they do not have enough knowledge and information to properly identify the sources in their vicinity. (authors)

  17. The Compositions: Biodegradable Material - Typical Resin, as Moulding Sands’ Binders

    Directory of Open Access Journals (Sweden)

    Major-Gabryś K.

    2015-03-01

    Full Text Available The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.

  18. Monte Carlo based radial shield design of typical PWR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gul, Anas; Khan, Rustam; Qureshi, M. Ayub; Azeem, Muhammad Waqar; Raza, S.A. [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan). Dept. of Nuclear Engineering; Stummer, Thomas [Technische Univ. Wien (Austria). Atominst.

    2016-11-15

    Neutron and gamma flux and dose equivalent rate distribution are analysed in radial and shields of a typical PWR type reactor based on the Monte Carlo radiation transport computer code MCNP5. The ENDF/B-VI continuous energy cross-section library has been employed for the criticality and shielding analysis. The computed results are in good agreement with the reference results (maximum difference is less than 56 %). It implies that MCNP5 a good tool for accurate prediction of neutron and gamma flux and dose rates in radial shield around the core of PWR type reactors.

  19. Lipomatosis of the sciatic nerve: typical and atypical MRI features

    International Nuclear Information System (INIS)

    Wong, Bernadette Zhi Ying; Amrami, Kimberly K.; Wenger, Doris E.; Dyck, P. James B.; Scheithauer, Bernd W.; Spinner, Robert J.

    2006-01-01

    Lipomatosis of nerve, also known as fibrolipomatous hamartoma, is a rare condition of nerve, usually affecting the median nerve. The MRI appearance is characteristic. We describe two cases of lipomatosis of nerve involving the sciatic nerve, an extremely unusual location for this lesion, in patients with sciatic neuropathy. These cases share the typical features previously described in the literature for other nerves, but also contain atypical features not previously highlighted, relating to the variability in distribution and extent of the fatty deposition. Recognition of the MRI appearance of this entity is important in order to avoid unnecessary attempts at surgical resection of this lesion. (orig.)

  20. Characterising mechanical transmission wire ropes’ typical failure modes

    Directory of Open Access Journals (Sweden)

    Edgar Espejo

    2007-01-01

    Full Text Available The National University of Colombia’s Engineering School’s AFIS research group has helped several public and private institutions during the last five years in analysing the causes of failures presented in elevation and trans- port machinery leading to expensive consequences and even the loss of life. A group of typical wire rope failure modes have been identified, along with their common causes. These are presented in this work to offer help to our industry’s engineers and technicians, allowing them to identify possible risk situations in their routine work regarding the wire ropes which they use and approaches for carrying out wire rope failure analysis.

  1. Typical IAEA operations at a fuel fabrication plant

    International Nuclear Information System (INIS)

    Morsy, S.

    1984-01-01

    The IAEA operations performed at a typical Fuel Fabrication Plant are explained. To make the analysis less general the case of Low Enriched Uranium (LEU) Fuel Fabrication Plants is considered. Many of the conclusions drawn from this analysis could be extended to other types of fabrication plants. The safeguards objectives and goals at LEU Fuel Fabrication Plants are defined followed by a brief description of the fabrication process. The basic philosophy behind nuclear material stratification and the concept of Material Balance Areas (MBA's) and Key Measurement Points (KMP's) is explained. The Agency operations and verification methods used during physical inventory verifications are illustrated

  2. Working memory training improves reading processes in typically developing children.

    Science.gov (United States)

    Loosli, Sandra V; Buschkuehl, Martin; Perrig, Walter J; Jaeggi, Susanne M

    2012-01-01

    The goal of this study was to investigate whether a brief cognitive training intervention results in a specific performance increase in the trained task, and whether there are transfer effects to other nontrained measures. A computerized, adaptive working memory intervention was conducted with 9- to 11-year-old typically developing children. The children considerably improved their performance in the trained working memory task. Additionally, compared to a matched control group, the experimental group significantly enhanced their reading performance after training, providing further evidence for shared processes between working memory and reading.

  3. Assessment of the quality seen in a restaurant typical theme

    Directory of Open Access Journals (Sweden)

    Francisco Alves Pinheiro

    2009-03-01

    Full Text Available To ensure the satisfaction of external customers it is necessary to know their needs. In this perspective, these work objectives assess the perception of quality by the customer outside of a restaurant located in the a restaurant typical theme located in the square of food “Bodódromo” the city of Petrolina/Pe. For both this was a case study, using the model servqual, Parasuraman et al (1985, for removal of information. The results indicated a need for improvement in the services provided by the restaurant.

  4. Hydrogen deflagration simulations under typical containment conditions for nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    Yanez, J., E-mail: jorge.yanez@kit.edu [Institute for Energy and Nuclear Technology, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe (Germany); Kotchourko, A.; Lelyakin, A. [Institute for Energy and Nuclear Technology, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe (Germany)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Lean H{sub 2}-air combustion experiments highly relevant to typical NPP simulated. Black-Right-Pointing-Pointer Analyzed effect of temperature, concentration of H{sub 2}, and steam concentration. Black-Right-Pointing-Pointer Similar conditions and H{sub 2} concentration yielded different combustion regimes. Black-Right-Pointing-Pointer Flame instabilities (FIs) were the effect driving divergences. Black-Right-Pointing-Pointer Model developed for acoustic FI in simulations. Agreement experiments obtained. - Abstract: This paper presents the modeling of low-concentration hydrogen deflagrations performed with the recently developed KYLCOM model specially created to perform calculations in large scale domains. Three experiments carried out in THAI facility (performed in the frames of international OECD THAI experimental program) were selected to be analyzed. The tests allow studying lean mixture hydrogen combustion at normal ambient, elevated temperature and superheated and saturated conditions. The experimental conditions considered together with the facility size and shape grant a high relevance degree to the typical NPP containment conditions. The results of the simulations were thoroughly compared with the experimental data, and the comparison was supplemented by the analysis of the combustion regimes taking place in the considered tests. Results of the analysis demonstrated that despite the comparatively small difference in mixture properties, three different combustion regimes can be definitely identified. The simulations of one of the cases required of the modeling of the acoustic-parametric instability which was carefully undertaken.

  5. Plutonium-239 production rate study using a typical fusion reactor

    International Nuclear Information System (INIS)

    Faghihi, F.; Havasi, H.; Amin-Mozafari, M.

    2008-01-01

    The purpose of the present paper is to compute fissile 239 Pu material by supposed typical fusion reactor operation to make the fuel requirement for other purposes (e.g. MOX fissile fuel, etc.). It is assumed that there is a fusion reactor has a cylindrical geometry and uses uniformly distributed deuterium-tritium as fuel so that neutron wall load is taken at 10(MW)/(m 2 ) . Moreover, the reactor core is surrounded by six suggested blankets to make best performance of the physical conditions described herein. We determined neutron flux in each considered blanket as well as tritium self-sufficiency using two groups neutron energy and then computation is followed by the MCNP-4C code. Finally, material depletion according to a set of dynamical coupled differential equations is solved to estimate 239 Pu production rate. Produced 239 Pu is compared with two typical fission reactors to find performance of plutonium breeding ratio in the case of the fusion reactor. We found that 0.92% of initial U is converted into fissile Pu by our suggested fusion reactor with thermal power of 3000 MW. For comparison, 239 Pu yield of suggested large scale PWR is about 0.65% and for LMFBR is close to 1.7%. The results show that the fusion reactor has an acceptable efficiency for Pu production compared with a large scale PWR fission reactor type

  6. Plutonium-239 production rate study using a typical fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Faghihi, F. [Research Center for Radiation Protection, Shiraz University, Shiraz (Iran, Islamic Republic of)], E-mail: faghihif@shirazu.ac.ir; Havasi, H.; Amin-Mozafari, M. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51154 Shiraz (Iran, Islamic Republic of)

    2008-05-15

    The purpose of the present paper is to compute fissile {sup 239}Pu material by supposed typical fusion reactor operation to make the fuel requirement for other purposes (e.g. MOX fissile fuel, etc.). It is assumed that there is a fusion reactor has a cylindrical geometry and uses uniformly distributed deuterium-tritium as fuel so that neutron wall load is taken at 10(MW)/(m{sup 2}) . Moreover, the reactor core is surrounded by six suggested blankets to make best performance of the physical conditions described herein. We determined neutron flux in each considered blanket as well as tritium self-sufficiency using two groups neutron energy and then computation is followed by the MCNP-4C code. Finally, material depletion according to a set of dynamical coupled differential equations is solved to estimate {sup 239}Pu production rate. Produced {sup 239}Pu is compared with two typical fission reactors to find performance of plutonium breeding ratio in the case of the fusion reactor. We found that 0.92% of initial U is converted into fissile Pu by our suggested fusion reactor with thermal power of 3000 MW. For comparison, {sup 239}Pu yield of suggested large scale PWR is about 0.65% and for LMFBR is close to 1.7%. The results show that the fusion reactor has an acceptable efficiency for Pu production compared with a large scale PWR fission reactor type.

  7. Daily intakes of naturally occurring radioisotopes in typical Korean foods

    International Nuclear Information System (INIS)

    Choi, Min-Seok; Lin Xiujing; Lee, Sun Ah; Kim, Wan; Kang, Hee-Dong; Doh, Sih-Hong; Kim, Do-Sung; Lee, Dong-Myung

    2008-01-01

    The concentrations of naturally occurring radioisotopes ( 232 Th, 228 Th, 230 Th, 228 Ra, 226 Ra, and 40 K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: 232 Th, 0.00-0.23; 228 Th, 0.00-2.04; 230 Th, 0.00-0.26; 228 Ra, 0.02-2.73; 226 Ra, 0.01-4.37 mBq/day; and 40 K, 0.01-5.71 Bq/day. The total daily intake of the naturally occurring radioisotopes measured in this study from food was 39.46 Bq/day. The total annual internal dose resulting from ingestion of radioisotopes in food was 109.83 μSv/y, and the radioisotope with the highest daily intake was 40 K. These values were same level compiled in other countries

  8. Emotion, gender, and gender typical identity in autobiographical memory.

    Science.gov (United States)

    Grysman, Azriel; Merrill, Natalie; Fivush, Robyn

    2017-03-01

    Gender differences in the emotional intensity and content of autobiographical memory (AM) are inconsistent across studies, and may be influenced as much by gender identity as by categorical gender. To explore this question, data were collected from 196 participants (age 18-40), split evenly between men and women. Participants narrated four memories, a neutral event, high point event, low point event, and self-defining memory, completed ratings of emotional intensity for each event, and completed four measures of gender typical identity. For self-reported emotional intensity, gender differences in AM were mediated by identification with stereotypical feminine gender norms. For narrative use of affect terms, both gender and gender typical identity predicted affective expression. The results confirm contextual models of gender identity (e.g., Diamond, 2012 . The desire disorder in research on sexual orientation in women: Contributions of dynamical systems theory. Archives of Sexual Behavior, 41, 73-83) and underscore the dynamic interplay between gender and gender identity in the emotional expression of autobiographical memories.

  9. A study on prioritizing typical women’s entrepreneur characteristics

    Directory of Open Access Journals (Sweden)

    Ebrahim Ramezani

    2014-07-01

    Full Text Available Entrepreneurship is one of the main pivot of progress and growth of every country. The spread of entrepreneurship particularly the role of women in this category has speeded up today more than any other times. Many of researchers believe that attention to women entrepreneurship plays remarkable role in soundness and safety of nation’s economy. Maybe in Iran less attention has been paid to this matter in proportion to other countries and due to various reasons, there are not many entrepreneur woman. However, employing typical entrepreneur women in various fields of productivity, industrial, commercial, social and cultural and even higher than these, in country’s political issue proves that women’s role is magnificent and in many cases they enjoy higher abilities in portion to men. In this paper, using additive ratio assessment (ARAS as a prioritizing method, eleven entrepreneur women were chosen for prioritizing criteria for measuring a typical women’s entrepreneurship characteristics. The results show that the balance between work and family among criteria are propounded as the highest weight and fulfilling different jobs simultaneously as the lowest weight.

  10. Economy of typical food: technical restrictions and organizative challenges

    Directory of Open Access Journals (Sweden)

    Elena Viganò

    2009-10-01

    Full Text Available The economic analysis of typical agri-food products requires to be focused on the following issues: i the specific features of the offering system; ii the technical restrictions established by the EU regulations on Protected designation of origin (Pdo and Pgi and, iii the strategies aimed at product differentiation and for value creation for the consumer. Considering this latest aspect, it is important to notice that the specificity of the agricultural raw materials, the use of traditional production techniques of production coming from the tradition of the place and certification represent only a prerequisite for the differentiation of the product on the market against standard products. The problem is that the specificity of local product comes from attributes (tangible and intangible of quality which are not directly accessible, nor verifiable, by the consumer when he/she makes purchasing choices. This situation persists despite the greater propensity of modern consumer to make investments in information and his/her greater attention and larger background towards the acknowledgement of different offers based on quality. This paper tends to develop an analysis on a theoretical and operative basis upon open strategies that can be implemented at the enterprise level, and that of agro-food chain and of territorial system in order to promote the quality of products to consumers. In particular, the work addresses the problems connected to the establishment of competitive advantages for Protected Designation of Origin (Pdo and Protected Geographical Indication (Pgi, highlighting that in order to achieve those advantages, firms offering typical products need to differentiate their offering on both material and immaterial ground acting on intrinsic and extrinsic attributes of quality of products, on specific features (natural, historical, cultural, etc. of territorial, on the efficiency of the offering organizational structure, and finally on the

  11. Economy of typical food: technical restrictions and organizative challenges

    Directory of Open Access Journals (Sweden)

    Elena Viganò

    2011-02-01

    Full Text Available The economic analysis of typical agri-food products requires to be focused on the following issues: i the specific features of the offering system; ii the technical restrictions established by the EU regulations on Protected designation of origin (Pdo and Pgi and, iii the strategies aimed at product differentiation and for value creation for the consumer. Considering this latest aspect, it is important to notice that the specificity of the agricultural raw materials, the use of traditional production techniques of production coming from the tradition of the place and certification represent only a prerequisite for the differentiation of the product on the market against standard products. The problem is that the specificity of local product comes from attributes (tangible and intangible of quality which are not directly accessible, nor verifiable, by the consumer when he/she makes purchasing choices. This situation persists despite the greater propensity of modern consumer to make investments in information and his/her greater attention and larger background towards the acknowledgement of different offers based on quality. This paper tends to develop an analysis on a theoretical and operative basis upon open strategies that can be implemented at the enterprise level, and that of agro-food chain and of territorial system in order to promote the quality of products to consumers. In particular, the work addresses the problems connected to the establishment of competitive advantages for Protected Designation of Origin (Pdo and Protected Geographical Indication (Pgi, highlighting that in order to achieve those advantages, firms offering typical products need to differentiate their offering on both material and immaterial ground acting on intrinsic and extrinsic attributes of quality of products, on specific features (natural, historical, cultural, etc. of territorial, on the efficiency of the offering organizational structure, and finally on the

  12. Acoustical conditions of typical classrooms in Hong Kong

    Science.gov (United States)

    Li, Kai Ming; Lam, Coriolanus C. L.

    2005-04-01

    This paper presents measurement results of the acoustical environments of local schools in Hong Kong. In the measurements, several acoustical aspects that affect verbal communication in classrooms have been studied. These conditions include outdoor and indoor ambient noise levels, signal-to-noise ratios, reverberation time and the speech transmission index. Typical classrooms in many different schools and other higher-education institutions have been selected in the present study. Experimental results are compared with such national standards as USA (ANSI S 12.60 V 2002), Australian/New Zealand (AS/NZS 2107:2000), China (GB/T 15508 V 1995) and other national and industrial standards. This study will form the basis of devising acceptable standards for use in Hong Kong. [Work supported by the Research Grants Council of the SAR Government, the Research Committee of the Hong Kong Polytechnic University and Architectural Services Department of the Hong Kong SAR Government.

  13. Failure mode and effects analysis on typical reactor trip system

    International Nuclear Information System (INIS)

    Eisawy, E.A.

    2010-01-01

    An updated failure mode and effects analysis, FMEA , has been performed on a typical reactor trip system. This upgrade helps to avoid system damage and ,as a result, extends the system service life. It also provides for simplified maintenance and surveillance testing. The operating conditions under which the system is to carry out its function and the operational profile expected for the system have been determined. The results of the FMEA have been given in terms of operating states of the subsystem.The results are given in form of table which is set up such that for a given failure one can read across it and determine which items remain operating in the system. From this data one can identify the number of components operating in the system for monitors pressure exceeds the setpoint pressure.

  14. Typical and atypical radiological manifestations of renal oncocytoma

    International Nuclear Information System (INIS)

    Bernaldez, P.; Iriborreu, M. A.; Rodriguez, M. L.; Martinez-Moya, M.; Rodriguez, A.; Navarro, S.

    2001-01-01

    Asses the Radiologic findings [ conventional X-ray, intravenous urography (IU), ultrasonography and computerized tomography (CT) ] of the renal oncocytomas and determine if there are characteristics that allow us to differentiate them from renal cell carcinoma (RCC). We performed a retrospective study of eight patients diagnosed of renal oncocytoma, analyzing the characteristics found in the plain radiography and IVU, ultrasonography and CT without and with i. v. contrast. The masses were well defined in seven cases and poorly defined in one, and were homogeneous on four occasions and heterogeneous on two. The remaining two were homogeneous, except for the presence of a central scar. Two lesions showed and aggressive biological behavior, coinciding with signs suggestive of malignancy from the radiological point of view. The fibrous scar is a typical but infrequent findings in renal oncocytoma that we can only detect by CT. It is not possible to differentiate it from aggressive lesions with imaging techniques, although orientative findings exist. (Author) 17 refs

  15. Air Leakage Rates in Typical Air Barrier Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Phillip W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-11-01

    Estimates for 2010 indicate that infiltration in residential buildings was responsible for 2.85 quads of energy (DOE 2014), which is about 3% of the total energy consumed in the US. One of the mechanisms being implemented to reduce this energy penalty is the use of air barriers as part of the building envelope. These technologies decrease airflow through major leakage sites such as oriented strand board (OSB) joints, and gaps around penetrations (e.g., windows, doors, pipes, electrical outlets) as indicated by Hun et al. (2014). However, most air barrier materials do not properly address leakage spots such as wall-to-roof joints and wall-to-foundation joints because these are difficult to seal, and because air barrier manufacturers usually do not provide adequate instructions for these locations. The present study focuses on characterizing typical air leakage sites in wall assemblies with air barrier materials.

  16. Typical equilibrium state of an embedded quantum system.

    Science.gov (United States)

    Ithier, Grégoire; Ascroft, Saeed; Benaych-Georges, Florent

    2017-12-01

    We consider an arbitrary quantum system coupled nonperturbatively to a large arbitrary and fully quantum environment. In the work by Ithier and Benaych-Georges [Phys. Rev. A 96, 012108 (2017)2469-992610.1103/PhysRevA.96.012108] the typicality of the dynamics of such an embedded quantum system was established for several classes of random interactions. In other words, the time evolution of its quantum state does not depend on the microscopic details of the interaction. Focusing on the long-time regime, we use this property to calculate analytically a partition function characterizing the stationary state and involving the overlaps between eigenvectors of a bare and a dressed Hamiltonian. This partition function provides a thermodynamical ensemble which includes the microcanonical and canonical ensembles as particular cases. We check our predictions with numerical simulations.

  17. [Injury patterns and typical stress situations in paragliding].

    Science.gov (United States)

    Bohnsack, M; Schröter, E

    2005-05-01

    Paragliding is known as a high risk sport with a substantial rate of severe and fatal injuries. Analysis of typical injury mechanisms and statistics showed that the total rate of paragliding injuries has decreased in recent years for an increasing number of pilots. In 2003, the rate of severe and fatal injuries in paragliding was less than that of other air sports and motorcycling. Through the introduction of a spine protector system in Germany and Austria, the number of vertebral fractures decreased significantly between 2000 and 2003. Most other injuries, especially of the lower extremities, could be avoided by adequate and farsighted flight behavior. Qualified instruction with regular training, standardized development of safety equipment and consequent analysis of paragliding injuries will help to improve the safety status in paragliding.

  18. Anthropic reasoning and typicality in multiverse cosmology and string theory

    International Nuclear Information System (INIS)

    Weinstein, Steven

    2006-01-01

    Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle is fundamentally ambiguous. It can be formulated in one of two ways, which we refer to as WAP 1 and WAP 2 . We show that WAP 2 , the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of 'typicality', and we argue that this assumption is both misguided and unjustified. WAP 1 , however, requires no such supplementation; it directly implies that any theory that assigns a non-zero probability to our universe predicts that we will observe our universe with probability one. We argue, therefore, that WAP 1 is preferable, and note that it has the benefit of avoiding the inductive overreach characteristic of much anthropic reasoning

  19. Anthropic reasoning and typicality in multiverse cosmology and string theory

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Steven [Perimeter Institute for Theoretical Physics, 31 Caroline St, Waterloo, ON N2L 2Y5 (Canada); Department of Philosophy, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2006-06-21

    Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle is fundamentally ambiguous. It can be formulated in one of two ways, which we refer to as WAP{sub 1} and WAP{sub 2}. We show that WAP{sub 2}, the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of 'typicality', and we argue that this assumption is both misguided and unjustified. WAP{sub 1}, however, requires no such supplementation; it directly implies that any theory that assigns a non-zero probability to our universe predicts that we will observe our universe with probability one. We argue, therefore, that WAP{sub 1} is preferable, and note that it has the benefit of avoiding the inductive overreach characteristic of much anthropic reasoning.

  20. Numerical Simulations for a Typical Train Fire in China

    Directory of Open Access Journals (Sweden)

    W. K. Chow

    2011-01-01

    Full Text Available Railway is the key transport means in China including the Mainland, Taiwan, and Hong Kong. Consequent to so many big arson and accidental fires in the public transport systems including trains and buses, fire safety in passenger trains is a concern. Numerical simulations with Computational Fluid Dynamics on identified fire scenarios with typical train compartments in China will be reported in this paper. The heat release rate of the first ignited item was taken as the input parameter. The mass lost rate of fuel vapor of other combustibles was estimated to predict the resultant heat release rates by the combustion models in the software. Results on air flow, velocity vectors, temperature distribution, smoke layer height, and smoke spread patterns inside the train compartment were analyzed. The results are useful for working out appropriate fire safety measures for train vehicles and determining the design fire for subway stations and railway tunnels.

  1. Aeroelastic Calculations Using CFD for a Typical Business Jet Model

    Science.gov (United States)

    Gibbons, Michael D.

    1996-01-01

    Two time-accurate Computational Fluid Dynamics (CFD) codes were used to compute several flutter points for a typical business jet model. The model consisted of a rigid fuselage with a flexible semispan wing and was tested in the Transonic Dynamics Tunnel at NASA Langley Research Center where experimental flutter data were obtained from M(sub infinity) = 0.628 to M(sub infinity) = 0.888. The computational results were computed using CFD codes based on the inviscid TSD equation (CAP-TSD) and the Euler/Navier-Stokes equations (CFL3D-AE). Comparisons are made between analytical results and with experiment where appropriate. The results presented here show that the Navier-Stokes method is required near the transonic dip due to the strong viscous effects while the TSD and Euler methods used here provide good results at the lower Mach numbers.

  2. GENERATION OF A TYPICAL METEOROLOGICAL YEAR FOR PORT HARCOURT ZONE

    Directory of Open Access Journals (Sweden)

    OGOLOMA O.B.

    2011-04-01

    Full Text Available This paper presents data for the typical meteorological year (TMY for the Port Harcourt climatic zone based on the hourly meteorological data recorded during the period 1983–2002, using the Finkelstein-Schafer statistical method. The data are the global solar radiation, wind velocity, dry bulb temperature, relative humidity, and others. The HVAC outside design conditions for the Port Harcourt climatic zone (latitude 4.44oN, longitude 7.1oE, elevation 20 m were found to be 26.7oC, 78.6% and 3.5 m/s for the dry bulb temperature, relative humidity and wind speed, respectively, and 13.5 MJ/m2/day for the global solar radiation. The TMY data for the zone are shown to be sufficiently reliable for engineering practice.

  3. Creep strain accumulation in a typical LMFBR piperun

    International Nuclear Information System (INIS)

    Johnstone, T.L.

    1975-01-01

    The analysis described allows the strain concentrations in typical LMFBR two anchor point uniplanar piperuns to be calculated. Account is taken of the effect of pipe elbows in attracting creep strain to themselves as well as possible movements of the thrust line due to strain redistribution. The influence of the initial load conditions is also examined. The stress relaxation analysis is facilitated by making the assumption that a cross-sectional stress distribution determined by the asymptotic fully developed state of creep exists at all times. Use is then made of Hoff(s) analogy between materials with a creep law of the Norton type and those with a corresponding non-linear elastic stress strain law, to determine complementary strain energy rates for straight pipes and bends. Ovalisation of the latter produces an increased strain energy rate which can be simply calculated by comparison with an equal length of straight pipe through employing a creep flexibility factor due to Spence. Deflection rates at any location in the pipework can then be evaluated in terms of the thermal restraint forces at that location by an application of Castigliano's principle. In particular for an anchor point the deflection rates are identically zero and this leads to the generation of 3 simultaneous differential equations determining the relaxation of the anchor reactions. Indicative results are presented for the continuous relaxation at 570 deg C of the thermally induced stress in a planar approximation to a typical LMFBR pipe run chosen to have peak elbow stresses close to the code maximum. The results indicate a ratio, after 10 5 hours, of 3 for creep strain concentration relative to initial peak strain (calculated on the assumption of fully elastic behavior) in the most severely affected elbow, when either austenitic 316 or 321 creep properties are employed

  4. Memory for sequences of events impaired in typical aging

    Science.gov (United States)

    Allen, Timothy A.; Morris, Andrea M.; Stark, Shauna M.; Fortin, Norbert J.

    2015-01-01

    Typical aging is associated with diminished episodic memory performance. To improve our understanding of the fundamental mechanisms underlying this age-related memory deficit, we previously developed an integrated, cross-species approach to link converging evidence from human and animal research. This novel approach focuses on the ability to remember sequences of events, an important feature of episodic memory. Unlike existing paradigms, this task is nonspatial, nonverbal, and can be used to isolate different cognitive processes that may be differentially affected in aging. Here, we used this task to make a comprehensive comparison of sequence memory performance between younger (18–22 yr) and older adults (62–86 yr). Specifically, participants viewed repeated sequences of six colored, fractal images and indicated whether each item was presented “in sequence” or “out of sequence.” Several out of sequence probe trials were used to provide a detailed assessment of sequence memory, including: (i) repeating an item from earlier in the sequence (“Repeats”; e.g., ABADEF), (ii) skipping ahead in the sequence (“Skips”; e.g., ABDDEF), and (iii) inserting an item from a different sequence into the same ordinal position (“Ordinal Transfers”; e.g., AB3DEF). We found that older adults performed as well as younger controls when tested on well-known and predictable sequences, but were severely impaired when tested using novel sequences. Importantly, overall sequence memory performance in older adults steadily declined with age, a decline not detected with other measures (RAVLT or BPS-O). We further characterized this deficit by showing that performance of older adults was severely impaired on specific probe trials that required detailed knowledge of the sequence (Skips and Ordinal Transfers), and was associated with a shift in their underlying mnemonic representation of the sequences. Collectively, these findings provide unambiguous evidence that the

  5. Far-infrared irradiation drying behavior of typical biomass briquettes

    International Nuclear Information System (INIS)

    Chen, N.N.; Chen, M.Q.; Fu, B.A.; Song, J.J.

    2017-01-01

    Infrared radiation drying behaviors of four typical biomass briquettes (populus tomentosa leaves, cotton stalk, spent coffee grounds and eucalyptus bark) were investigated based on a lab-scale setup. The effect of radiation source temperatures (100–200 °C) on the far-infrared drying kinetics and heat transfer of the samples was addressed. As the temperature went up from 100 °C to 200 °C, the time required for the four biomass briquettes drying decreased by about 59–66%, and the average values of temperature for the four biomass briquettes increased by about 33–39 °C, while the average radiation heat transfer fluxes increased by about 3.3 times (3.7 times only for the leaves). The specific energy consumptions were 0.622–0.849 kW h kg"−"1. The Modified Midilli model had the better representing for the moisture ratio change of the briquettes. The values of the activation energy for the briquettes in the first falling rate stage were between 20.35 and 24.83 kJ mol"−"1, while those in the second falling rate stage were between 17.89 and 21.93 kJ mol"−"1. The activation energy for the eucalyptus bark briquette in two falling rate stages was the least one, and that for the cotton stalk briquette was less than that for the rest two briquettes. - Highlights: • Far infrared drying behaviors of four typical biomass briquettes were addressed. • The effect of radiation source temperatures on IR drying kinetics was stated. • Radiation heat transfer flux between the sample and heater was evaluated. • Midilli model had the better representing for the drying process of the samples.

  6. DISRUPTION OF CONDITIONED REWARD ASSOCIATION BY TYPICAL AND ATYPICAL ANTIPSYCHOTICS

    Science.gov (United States)

    Danna, C.L.; Elmer, G.I.

    2013-01-01

    Antipsychotic drugs are broadly classified into typical and atypical compounds; they vary in their pharmacological profile however a common component is their antagonist effects at the D2 dopamine receptors (DRD2). Unfortunately, diminished DRD2 activation is generally thought to be associated with the severity of neuroleptic-induced anhedonia. The purpose of this study was to determine the effect of the atypical antipsychotic olanzapine and typical antipsychotic haloperidol in a paradigm that reflects the learned transfer of incentive motivational properties to previously neutral stimuli, namely autoshaping. In order to provide a dosing comparison to a therapeutically relevant endpoint, both drugs were tested against amphetamine-induced disruption of prepulse inhibition as well. In the autoshaping task, rats were exposed to repeated pairings of stimuli that were differentially predictive of reward delivery. Conditioned approach to the reward predictive cue (sign-tracking) and to the reward (goal-tracking) increased during repeated pairings in the vehicle treated rats. Haloperidol and olanzapine completely abolished this behavior at relatively low doses (100 μg/kg). This same dose was the threshold dose for each drug to antagonize the sensorimotor gating deficits produced by amphetamine. At lower doses (3–30 μg/kg) both drugs produced a dose-dependent decrease in conditioned approach to the reward predictive cue. There was no difference between drugs at this dose range which indicates that olanzapine disrupts autoshaping at a significantly lower proposed DRD2 receptor occupancy. Interestingly, neither drug disrupted conditioned approach to the reward at the same dose range that disrupted conditioned approach to the reward predictive cue. Thus, haloperidol and olanzapine, at doses well below what is considered therapeutically relevant, disrupts the attribution of incentive motivational value to previously neutral cues. Drug effects on this dimension of reward

  7. A brief history of typical absence seizures - Petit mal revisited.

    Science.gov (United States)

    Brigo, Francesco; Trinka, Eugen; Lattanzi, Simona; Bragazzi, Nicola Luigi; Nardone, Raffaele; Martini, Mariano

    2018-03-01

    In this article, we have traced back the history of typical absence seizures, from their initial clinical description to the more recent nosological position. The first description of absence seizures was made by Poupart in 1705 and Tissot in 1770. In 1824, Calmeil introduced the term "absences", and in 1838, Esquirol for the first time used the term petit mal. Reynolds instead used the term "epilepsia mitior" (milder epilepsy) and provided a comprehensive description of absence seizures (1861). In 1854, Delasiauve ranked absences as the seizure type with lower severity and introduced the concept of idiopathic epilepsy. Otto Binswanger (1899) discussed the role of cortex in the pathophysiology of "abortive seizures", whereas William Gowers (1901) emphasized the importance of a detailed clinical history to identify nonmotor seizures or very mild motor phenomena which otherwise may go unnoticed or considered not epileptic. At the beginning of the 20th Century, the term pyknolepsy was introduced, but initially was not universally considered as a type of epilepsy; it was definitely recognized as an epileptic entity only in 1945, based on electroencephalogram (EEG) recordings. Hans Berger, the inventor of the EEG, made also the first EEG recording of an atypical absence (his results were published only in 1933), whereas the characteristic EEG pattern was reported by neurophysiologists of the Harvard Medical School in 1935. The discovery of EEG made it also possible to differentiate absence seizures from so called "psychomotor" seizures occurring in temporal lobe epilepsy. Penfield and Jasper (1938) considered absences as expression of "centrencephalic epilepsy". Typical absences seizures are now classified by the International League Against Epilepsy among generalized nonmotor (absence) seizures. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. New genetic tools to identify and protect typical italian products

    Directory of Open Access Journals (Sweden)

    Sergio Lanteri

    2011-02-01

    Full Text Available During last decades the use of local varieties was strongly reduced due to introduction of modern cultivars characterized by higher yield, and breed for different traits of agronomic value. However, these cultivars not always have the quality aspects that was found in old traditional and typical crops also depending from the know-how of traditional cultivation. Nowadays the practise of intensive agriculture select only a small number of species and varieties with a consequent reduction of the diversity in agro-ecosystems and risk of loss of important alleles characterizing genetic materials adapted to specific environments. The creation of quality marks of the European Union proved to be a successful system to protect typical products through the Denomination of Origins (PDO- Protected Denomination of Origin and PGI- Protected Geographical Indication. However, the protection of quality needs efficient instruments to discriminate DOP or IGP varieties in the field and to trace them along the agro-food chain. DNA fingerprinting represents an excellent system to discriminate herbaceous and tree species as well as to quantify the amount of genetic variability present in germplasm collections. The paper describes several examples in which AFLPs, SSRs and minisatellite markers were successfully used to identify tomato, artichoke, grape, apple and walnut varieties proving to be effective in discriminating also closely related genetic material. DNA fingerprinting based on SSR is also a powerful tool to trace and authenticate row plant materials in agro-food chains. The paper describes examples of varieties traceability in the food chains durum wheat, olive, apple and tomato pursued through the identification of SSR allelic profiles obtained from DNA isolated from complex highly processed food, such as bread, olive oil, apple pureè and nectar and peeled tomato.

  9. New genetic tools to identify and protect typical italian products

    Directory of Open Access Journals (Sweden)

    Sergio Lanteri

    2009-10-01

    Full Text Available During last decades the use of local varieties was strongly reduced due to introduction of modern cultivars characterized by higher yield, and breed for different traits of agronomic value. However, these cultivars not always have the quality aspects that was found in old traditional and typical crops also depending from the know-how of traditional cultivation. Nowadays the practise of intensive agriculture select only a small number of species and varieties with a consequent reduction of the diversity in agro-ecosystems and risk of loss of important alleles characterizing genetic materials adapted to specific environments. The creation of quality marks of the European Union proved to be a successful system to protect typical products through the Denomination of Origins (PDO- Protected Denomination of Origin and PGI- Protected Geographical Indication. However, the protection of quality needs efficient instruments to discriminate DOP or IGP varieties in the field and to trace them along the agro-food chain. DNA fingerprinting represents an excellent system to discriminate herbaceous and tree species as well as to quantify the amount of genetic variability present in germplasm collections. The paper describes several examples in which AFLPs, SSRs and minisatellite markers were successfully used to identify tomato, artichoke, grape, apple and walnut varieties proving to be effective in discriminating also closely related genetic material. DNA fingerprinting based on SSR is also a powerful tool to trace and authenticate row plant materials in agro-food chains. The paper describes examples of varieties traceability in the food chains durum wheat, olive, apple and tomato pursued through the identification of SSR allelic profiles obtained from DNA isolated from complex highly processed food, such as bread, olive oil, apple pureè and nectar and peeled tomato.

  10. Longitudinal changes in cortical thickness in autism and typical development.

    Science.gov (United States)

    Zielinski, Brandon A; Prigge, Molly B D; Nielsen, Jared A; Froehlich, Alyson L; Abildskov, Tracy J; Anderson, Jeffrey S; Fletcher, P Thomas; Zygmunt, Kristen M; Travers, Brittany G; Lange, Nicholas; Alexander, Andrew L; Bigler, Erin D; Lainhart, Janet E

    2014-06-01

    The natural history of brain growth in autism spectrum disorders remains unclear. Cross-sectional studies have identified regional abnormalities in brain volume and cortical thickness in autism, although substantial discrepancies have been reported. Preliminary longitudinal studies using two time points and small samples have identified specific regional differences in cortical thickness in the disorder. To clarify age-related trajectories of cortical development, we examined longitudinal changes in cortical thickness within a large mixed cross-sectional and longitudinal sample of autistic subjects and age- and gender-matched typically developing controls. Three hundred and forty-five magnetic resonance imaging scans were examined from 97 males with autism (mean age = 16.8 years; range 3-36 years) and 60 males with typical development (mean age = 18 years; range 4-39 years), with an average interscan interval of 2.6 years. FreeSurfer image analysis software was used to parcellate the cortex into 34 regions of interest per hemisphere and to calculate mean cortical thickness for each region. Longitudinal linear mixed effects models were used to further characterize these findings and identify regions with between-group differences in longitudinal age-related trajectories. Using mean age at time of first scan as a reference (15 years), differences were observed in bilateral inferior frontal gyrus, pars opercularis and pars triangularis, right caudal middle frontal and left rostral middle frontal regions, and left frontal pole. However, group differences in cortical thickness varied by developmental stage, and were influenced by IQ. Differences in age-related trajectories emerged in bilateral parietal and occipital regions (postcentral gyrus, cuneus, lingual gyrus, pericalcarine cortex), left frontal regions (pars opercularis, rostral middle frontal and frontal pole), left supramarginal gyrus, and right transverse temporal gyrus, superior parietal lobule, and

  11. Experimental Research on Boundary Shear Stress in Typical Meandering Channel

    Science.gov (United States)

    Chen, Kai-hua; Xia, Yun-feng; Zhang, Shi-zhao; Wen, Yun-cheng; Xu, Hua

    2018-06-01

    A novel instrument named Micro-Electro-Mechanical System (MEMS) flexible hot-film shear stress sensor was used to study the boundary shear stress distribution in the generalized natural meandering open channel, and the mean sidewall shear stress distribution along the meandering channel, and the lateral boundary shear stress distribution in the typical cross-section of the meandering channel was analysed. Based on the measurement of the boundary shear stress, a semi-empirical semi-theoretical computing approach of the boundary shear stress was derived including the effects of the secondary flow, sidewall roughness factor, eddy viscosity and the additional Reynolds stress, and more importantly, for the first time, it combined the effects of the cross-section central angle and the Reynolds number into the expressions. Afterwards, a comparison between the previous research and this study was developed. Following the result, we found that the semi-empirical semi-theoretical boundary shear stress distribution algorithm can predict the boundary shear stress distribution precisely. Finally, a single factor analysis was conducted on the relationship between the average sidewall shear stress on the convex and concave bank and the flow rate, water depth, slope ratio, or the cross-section central angle of the open channel bend. The functional relationship with each of the above factors was established, and then the distance from the location of the extreme sidewall shear stress to the bottom of the open channel was deduced based on the statistical theory.

  12. Musical Mnemonics Enhance Verbal Memory in Typically Developing Children

    Directory of Open Access Journals (Sweden)

    David Knott

    2018-05-01

    Full Text Available The purpose of this study was to compare the effects of musical mnemonics vs. spoken word in training verbal memory in children. A randomized control trial of typically-developing 9–11 year old children was conducted using the Rey Auditory Verbal Learning Test (RAVLT, a test measuring a participant's ability to recall a list of 15 words over multiple exposures. Members of the group who listened to words sung to them recalled an average of 20% more words after listening to and recalling an interference list than members of the control group who listened to the same words spoken. This difference persisted, though slightly smaller (17% when participants recalled words after a 15-min waiting period. Additionally, group participants who listened to words sung demonstrated a higher incidence of words recalled in correct serial order. Key findings were all statistically significant at the P < 0.05 level. Enhanced serial order recall points to the musical pitch/rhythm structure enhancing sequence memory as a potential mnemonic mechanism. No significant differences were found in serial position effects between groups. The findings suggest that musical mnemonic training may be more effective than rehearsal with spoken words in verbal memory learning tasks in 9–11 year olds.

  13. Physical characteristics and resistance parameters of typical urban cyclists.

    Science.gov (United States)

    Tengattini, Simone; Bigazzi, Alexander York

    2018-03-30

    This study investigates the rolling and drag resistance parameters and bicycle and cargo masses of typical urban cyclists. These factors are important for modelling of cyclist speed, power and energy expenditure, with applications including exercise performance, health and safety assessments and transportation network analysis. However, representative values for diverse urban travellers have not been established. Resistance parameters were measured utilizing a field coast-down test for 557 intercepted cyclists in Vancouver, Canada. Masses were also measured, along with other bicycle attributes such as tire pressure and size. The average (standard deviation) of coefficient of rolling resistance, effective frontal area, bicycle plus cargo mass, and bicycle-only mass were 0.0077 (0.0036), 0.559 (0.170) m 2 , 18.3 (4.1) kg, and 13.7 (3.3) kg, respectively. The range of measured values is wider and higher than suggested in existing literature, which focusses on sport cyclists. Significant correlations are identified between resistance parameters and rider and bicycle attributes, indicating higher resistance parameters for less sport-oriented cyclists. The findings of this study are important for appropriately characterising the full range of urban cyclists, including commuters and casual riders.

  14. Typical and atypical clinical presentation of uterine myomas

    Directory of Open Access Journals (Sweden)

    Wen-Hsiang Su

    2012-10-01

    Full Text Available Myoma is the most common benign neoplasm that can occur in the female reproductive system, most frequently seen in women in their 50s. Although the majority of myomas are asymptomatic, some patients have symptoms and/or signs of varying degrees. Typical myoma-related symptoms or signs include: (1 menstrual disturbances like menorrhagia, dysmenorrhea and intermenstrual bleeding, (2 pelvic pain unrelated to menstruation, (3 compression symptoms, similar to a sensation of bloatedness, urinary frequency and constipation, (4 subfertility status such as recurrent abortion, preterm labor, dystocia with an increased incidence of Cesarean section, and postpartum hemorrhage, and (5 cosmetic problems due to increased abdominal girth However, there are undoubtedly some clinical presentations secondary to uterine myomas are not so specific, such as: (1 uncommon compression-related symptoms, (2 cardiac symptom and atypical symptoms secondary to vascular involvement or dissemination, (3 abdominal symptoms mimicking pelvic carcinomatosis, (4 dyspnea, (5 pruritus, (6 hiccup or internal bleeding, and (7 vaginal protruding mass or uterine inversion. Familiarization with these symptoms and awareness of other unusual or atypical presentations of uterine myomas will remind clinical practitioners of their significance, and of the necessity of follow-up examinations and individualized management to fit the needs and childbirth desires of the patients.

  15. Typical balance exercises or exergames for balance improvement?

    Science.gov (United States)

    Gioftsidou, Asimenia; Vernadakis, Nikolaos; Malliou, Paraskevi; Batzios, Stavros; Sofokleous, Polina; Antoniou, Panagiotis; Kouli, Olga; Tsapralis, Kyriakos; Godolias, George

    2013-01-01

    Balance training is an effective intervention to improve static postural sway and balance. The purpose of the present study was to investigate the effectiveness of the Nintendo Wii Fit Plus exercises for improving balance ability in healthy collegiate students in comparison with a typical balance training program. Forty students were randomly divided into two groups, a traditional (T group) and a Nintendo Wii group (W group) performed an 8 week balance program. The "W group" used the interactive games as a training method, while the "T group" used an exercise program with mini trampoline and inflatable discs (BOSU). Pre and Post-training participants completed balance assessments. Two-way repeated measures analyses of variance (ANOVAs) were conducted to determine the effect of training program. Analysis of the data illustrated that both training program groups demonstrated an improvement in Total, Anterior-posterior and Medial Lateral Stability Index scores for both limbs. Only at the test performed in the balance board with anterior-posterior motion, the improvement in balance ability was greater in the "T group" than the "W group", when the assessment was performed post-training (p=0.023). Findings support the effectiveness of using the Nintendo Wii gaming console as a balance training intervention tool.

  16. Facilitating complex shape drawing in Williams syndrome and typical development.

    Science.gov (United States)

    Hudson, Kerry D; Farran, Emily K

    2013-07-01

    Individuals with Williams syndrome (WS) produce drawings that are disorganised, likely due to an inability to replicate numerous spatial relations between parts. This study attempted to circumvent these drawing deficits in WS when copying complex combinations of one, two and three shapes. Drawing decisions were reduced by introducing a number of facilitators, for example, by using distinct colours and including facilitatory cues on the response sheet. Overall, facilitation improved drawing in the WS group to a comparable level of accuracy as typically developing participants (matched for non-verbal ability). Drawing accuracy was greatest in both groups when planning demands (e.g. starting location, line lengths and changes in direction) were reduced by use of coloured figures and providing easily distinguished and clearly grouped facilitatory cues to form each shape. This study provides the first encouraging evidence to suggest that drawing of complex shapes in WS can be facilitated; individuals with WS might be receptive to remediation programmes for drawing and handwriting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Typically Diverse: The Nature of Urban Agriculture in South Australia

    Directory of Open Access Journals (Sweden)

    Georgia Pollard

    2018-03-01

    Full Text Available In our visions of the future, urban agriculture has long been considered an integral part of the ‘sustainable city’. Yet urban agriculture is an incredibly diverse and variable field of study, and many practical aspects remain overlooked and understudied. This paper explores the economic sustainability of urban agriculture by focusing on the physical, practical, and economic aspects of home food gardens in South Australia. New data from the Edible Gardens project online survey is presented on a broad range of current garden setups, including a figure illustrating the statistically typical South Australian food garden. The differences between the survey data and a recent optimized garden model further highlight the gap in knowledge regarding existing home food gardens. With regard to the financial accessibility and economic sustainability of home food gardens, there is also still much more work to be done. Although saving money is a top motivation, with many survey respondents believing that they do succeed in saving money, it remains to be seen whether their current gardening practices support this aspiration. Measurement of the full costs of different gardens would allow for better predictions of whether growing food can save household’s money and under what circumstances.

  18. Dorsal anterior cingulate cortex in typically developing children: Laterality analysis

    Directory of Open Access Journals (Sweden)

    Jue Wang

    2015-10-01

    Full Text Available We aimed to elucidate the dACC laterality in typically developing children and their sex/age-related differences with a sample of 84 right-handed children (6–16 years, 42 boys. We first replicated the previous finding observed in adults that gray matter density asymmetry in the dACC was region-specific: leftward (left > right in its superior part, rightward (left < right in its inferior part. Intrinsic connectivity analysis of these regions further revealed region-specific asymmetric connectivity profiles in dACC as well as their sex and age differences. Specifically, the superior dACC connectivity with frontoparietal network and the inferior dACC connectivity with visual network are rightward. The superior dACC connectivity with the default network (lateral temporal cortex was more involved in the left hemisphere. In contrast, the inferior dACC connectivity with the default network (anterior medial prefrontal cortex was more lateralized towards the right hemisphere. The superior dACC connectivity with lateral visual cortex was more distinct across two hemispheres in girls than that in boys. This connection in boys changed with age from right-prominent to left-prominent asymmetry whereas girls developed the connection from left-prominent to no asymmetry. These findings not only highlight the complexity and laterality of the dACC but also provided insights into dynamical structure–function relationships during the development.

  19. Comparison of typical mega cities in China using emergy synthesis

    Science.gov (United States)

    Zhang, L. X.; Chen, B.; Yang, Z. F.; Chen, G. Q.; Jiang, M. M.; Liu, G. Y.

    2009-06-01

    An emergy-based comparison analysis is conducted for three typical mega cities in China, i.e., Beijing, Shanghai and Guangzhou, from 1990 to 2005 in four perspectives including emergy intensity, resource structure, environmental pressure and resource use efficiency. A new index of non-renewable emergy/money ratio is established to indicate the utilization efficiency of the non-renewable resources. The results show that for the three mega urban systems, Beijing, Shanghai and Guangzhou, the total emergy inputs were 3.76E+23, 3.54E+23, 2.52E+23 sej in 2005, of which 64.88%, 91.45% and 72.28% were imported from the outsides, respectively. As to the indicators of emergy intensity involving the total emergy use, emergy density and emergy use per cap, three cities exhibited similar overall increase trends with annual fluctuations from 1990 to 2005. Shanghai achieved the highest level of economic development and non-renewable resource use efficiency, and meanwhile, lower proportion of renewable resource use and higher environmental pressure compared to those of Beijing and Guangzhou. Guangzhou has long term sustainability considering an amount of local renewable resources used, per capita emergy used, energy consumption per unit GDP and the ratio of waste to renewable emergy. It can be concluded that different emergy-based evaluation results arise from different geographical locations, resources endowments, industrial structures and urban orientations of the concerned mega cities.

  20. A quantitative evaluation of seismic margin of typical sodium piping

    International Nuclear Information System (INIS)

    Morishita, Masaki

    1999-05-01

    It is widely recognized that the current seismic design methods for piping involve a large amount of safety margin. From this viewpoint, a series of seismic analyses and evaluations with various design codes were made on typical LMFBR main sodium piping systems. Actual capability against seismic loads were also estimated on the piping systems. Margins contained in the current codes were quantified based on these results, and potential benefits and impacts to the piping seismic design were assessed on possible mitigation of the current code allowables. From the study, the following points were clarified; 1) A combination of inelastic time history analysis and true (without margin)strength capability allows several to twenty times as large seismic load compared with the allowable load with the current methods. 2) The new rule of the ASME is relatively compatible with the results of inelastic analysis evaluation. Hence, this new rule might be a goal for the mitigation of seismic design rule. 3) With this mitigation, seismic design accommodation such as equipping with a large number of seismic supports may become unnecessary. (author)

  1. Comparative analysis on flexibility requirements of typical Cryogenic Transfer lines

    Science.gov (United States)

    Jadon, Mohit; Kumar, Uday; Choukekar, Ketan; Shah, Nitin; Sarkar, Biswanath

    2017-04-01

    The cryogenic systems and their applications; primarily in large Fusion devices, utilize multiple cryogen transfer lines of various sizes and complexities to transfer cryogenic fluids from plant to the various user/ applications. These transfer lines are composed of various critical sections i.e. tee section, elbows, flexible components etc. The mechanical sustainability (under failure circumstances) of these transfer lines are primary requirement for safe operation of the system and applications. The transfer lines need to be designed for multiple design constraints conditions like line layout, support locations and space restrictions. The transfer lines are subjected to single load and multiple load combinations, such as operational loads, seismic loads, leak in insulation vacuum loads etc. [1]. The analytical calculations and flexibility analysis using professional software are performed for the typical transfer lines without any flexible component, the results were analysed for functional and mechanical load conditions. The failure modes were identified along the critical sections. The same transfer line was then refurbished with the flexible components and analysed for failure modes. The flexible components provide additional flexibility to the transfer line system and make it safe. The results obtained from the analytical calculations were compared with those obtained from the flexibility analysis software calculations. The optimization of the flexible component’s size and selection was performed and components were selected to meet the design requirements as per code.

  2. Aqueous-chlorine leaching of typical Canadian uranium ores

    International Nuclear Information System (INIS)

    Haque, K.E.

    1982-01-01

    Laboratory-scale aqueous-chlorine leaches were conducted on quartz-pebble conglomerates, pegmatite and vein-type ores. Optimum leach temperatures, pulp density and retention times were determined. Uranium extraction of 98 per cent was obtained from the Elliot Lake, Madawaska Mines of Bancroft and Rabbit Lake ores, 96 per cent from the Key Lake ore and 86 per cent from the Agnew Lake ore. However, tailings containing 15-20 pCi g -1 of radium-226 were obtained only from the Elliot Lake and Agnew lake quartz-pebble conglomerates and Bancroft pegmatite-type ores by second-stage leaches with HCl. The second-stage leach results indicate that multistage (3 or 4) acid-chloride or salt-chloride leaches might be effective to obtain tailings containing 15-20 pCi 226 Ra g -1 from the high-grade vein-type ores. Comparative reagent-cost estimates show that the sulphuric-acid leach process is far less expensive than aqueous chlorine leaching. Nevertheless, only the aqueous chlorine and acid-chloride leaches in stages are effective in producing tailings containing 15-20 pCi 226 Ra g -1 from the typical Canadian uranium ores. (Auth.)

  3. Typical intellectual engagement and cognition in old age.

    Science.gov (United States)

    Dellenbach, Myriam; Zimprich, Daniel

    2008-03-01

    Typical Intellectual Engagement (TIE) comprises the preference to engage in cognitively demanding activities and has been proposed as a potential explanatory variable of individual differences in cognitive abilities. Little is known, however, about the factorial structure of TIE, its relations to socio-demographic variables, and its influence on intellectual functioning in old age. In the present study, data of 364 adults (65-81 years) from the Zurich Longitudinal Study on Cognitive Aging (ZULU) were used to investigate the factorial structure of TIE and to examine the hypothesis that TIE is associated more strongly with crystallized intelligence than with fluid intelligence in old age. A measurement model of a second order factor based on a structure of four correlated first order factors (Reading, Problem Solving, Abstract Thinking, and Intellectual Curiosity) evinced an excellent fit. After controlling for age, sex, and formal education, TIE was more strongly associated with crystallized intelligence than with fluid intelligence, comparable to results in younger persons. More detailed analyses showed that this association is mostly defined via Reading and Intellectual Curiosity.

  4. The use of conjunctions by children with typical language development.

    Science.gov (United States)

    Glória, Yasmin Alves Leão; Hanauer, Letícia Pessota; Wiethan, Fernanda Marafiga; Nóro, Letícia Arruda; Mota, Helena Bolli

    2016-07-04

    To investigate the use of conjunctions in the spontaneous speech of three years old children with typical language development, who live in Santa Maria - RS. 45 children, aged 3:0;0 - 3:11;29 (years:months;days) from the database of the Center for the Study of Language and Speech (CELF) participated of this study. The spontaneous speech of each child was transcribed and followed by analysis of the samples to identify the types of conjunctions for each age group. The samples were statistically analyzed using the R software that allowed the evaluation of the number and type of conjunctions used in each age group by comparing them with each other. The data indicated that the higher the age of the child, the greater the number of types of conjunctions used by them. The comparison between age groups showed significant differences when comparing the average number of conjunctions per age group, as well as for additive conjunctions and subordinating conjunctions. At age of three the children begin to develop the grammatical use of conjunctions, early appearing additive, adversative and explanatory coordinating conjunctions, and at 3:6 they are able to use the most complex conjunctions, as subordinating conjunctions.

  5. Aging Management Plan for a Typical Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, Mahsa; Nazififard, Mohammad; Suh, Kune Y. [Seoul National University, Seoul (Korea, Republic of)

    2012-05-15

    Development of an aging management plan (AMP) is a crucial contributor to maintaining the reactor safety and controlling the risk of degradation of the concrete reactor building of a nuclear power plant. The design, operation and utilization of a research reactor (RR) fundamentally differ from those of power reactors. The AMP should nonetheless be present on account of radioactive materials and radiation risks involved. This is mainly because the RR is deemed to be used as an experiment itself or to conduct separate experiments during its operation. The AMP aims to determine the requisites for specific structural concrete components of the reactor building that entail regular inspections and maintenance to ensure safe and reliable operation of the plant. The safety of a RR necessitates the provision which is made in its design to facilitate aging management. Aging management of RR's structures is one of the vital factors to safety, to ensure continued adequacy of the safety level, reliable operation of the reactor, and compliance with the operational limits and conditions.Moreover, engineering systems should be qualified to meet the functional requirements for which they were designed with aging and environmental conditions for all situations and at all times taken into account. This study aims to present an integrated methodology for the application of an AMP for the concrete of the reactor building of a typical RR. For the purpose of safety analysis, geometry and ambient conditions were taken from a 5 MW pool-type, light-water moderated, heterogeneous, solid fuel RR in which the water is also used for cooling and shielding (Fig. 1). The reactor core is immersed in either section of a two-section concrete pool filled with water. This paper makes available background information regarding the document and the strategy developed to manage potential degradation of the reactor building concrete as well as specific programs and preventive and corrective

  6. Typical tumors of the petrous bone; Typische Tumoren des Felsenbeins

    Energy Technology Data Exchange (ETDEWEB)

    Ahlhelm, F.; Mueller, U. [Kantonsspital Baden AG, Abteilung fuer Neuroradiologie, Institut fuer Radiologie, Baden (Switzerland); Ulmer, S. [Medizinisch-Radiologisches Institut, Zuerich (Switzerland)

    2014-04-15

    In the region of the petrous bone, inner acoustic canal and cerebellopontine angle, a variety of different tissues can be found, such as bony, epithelial, neural and vascular structures. Tumorous or tumor-like lesions, vascular or bony malformations or other pathologies can therefore be found in all of these areas. We discuss various frequently occurring tumorous or tumor-like pathologies including congential lesions, such as mucoceles, inflammatory disorders including osteomyelitis, pseudotumors and Wegener's granulomatosis. Benign non-neoplastic lesions, such as cholesteatoma, cholesterol granuloma, epidermoid and benign neoplastic tumors, such as the most commonly found vestibular schwannoma, meningeoma, paraganglioma, vascular pathologies and finally malignant lesions, such as metastasis, chordoma or chondrosarcoma and endolymphatic sac tumor (ELST) are also discussed. The emphasis of this article is on the appearance of these entities in computed tomography (CT) and more so magnetic resonance imaging (MRI), it provides key facts and typical images and discusses possibilities how to distinguish these pathologies. (orig.) [German] In der Region des Felsenbein, inneren Gehoerkanals und Kleinhirnbrueckenwinkels findet sich eine Vielzahl an unterschiedlichen Gewebearten inklusive knoechernes, epitheliales, nervales und vaskulaeres Gewebe. Tumoren oder tumoraehnliche Laesionen, ossaere oder vaskulaere Pathologien koennen entsprechend dort gefunden werden. Wir diskutieren verschiedene Tumoren oder tumoraehnliche Pathologien inklusive angeborene Laesionen wie Muko- und Meningozelen, entzuendliche Veraenderungen wie die Osteomyelitis, Pseudotumoren, die Wegener-Granulomatose, nichtneoplastische Tumoren wie das Epidermoid, Cholesteatom oder Cholesterolgranulom und gutartige neoplastische Tumoren wie das am haeufigsten zu findende Vestibularisschwannom, das Paragangliom und das Meningeom, Gefaessprozesse/-pathologien und schliesslich maligne Laesionen wie Metastasen

  7. Thermal properties of typical chernozems in Kursk Oblast

    Science.gov (United States)

    Arkhangel'skaya, T. A.; Velichenko, M. V.; Tikhonravova, P. I.

    2016-10-01

    Thermal diffusivity and heat capacity of virgin and plowed heavy loamy typical chernozems of Kursk oblast were studied. Thermal diffusivity was determined in the course of step-by-step drying of the initially capillary-saturated samples to the air-dry state. Specific heat capacity was determined for absolutely dry samples. Volumetric heat capacity was calculated according to the de Vries equation. Thermal diffusivity varied within the ranges of (1.15-3.46) × 10-7 m2/s in the Ap horizon, (1.14-3.35) × 10-7 m2/s in the A1 horizon, (1.49-3.70) × 10-7 m2/s in the AB horizon, (1.49-3.91) × 10-7 m2/s in the B1 horizon, and (1.60-3.80) × 10-7 m2/s in the Bca horizon. The thermal diffusivity vs. water content dependencies had distinct maximums and were flattened in the range of low water contents. The maximums were most pronounced for the mineral B1 and Bca horizons; for the A1 and Ap horizons, the curves were rather S-shaped. Volumetric heat capacity of the air-dry soils varied from 0.96 J/(cm3 K) in the A1 horizon to 1.31 J/(cm3 K) in the Bca horizon; in the state of capillary saturation, it varied from 2.79 J/(cm3 K) in the A1 horizon to 3.28 J/(cm3 K) in the Bca horizon. Thermal properties of topsoil horizons were higher in the plowed chernozem compared with the virgin chernozem, which is explained by an increase in the bulk density and a decrease in the organic matter content in the plowed soil.

  8. Integrated SNG Production in a Typical Nordic Sawmill

    Directory of Open Access Journals (Sweden)

    Sennai Mesfun

    2016-04-01

    Full Text Available Advanced biomass-based motor fuels and chemicals are becoming increasingly important to replace fossil energy sources within the coming decades. It is likely that the new biorefineries will evolve mainly from existing forest industry sites, as they already have the required biomass handling infrastructure in place. The main objective of this work is to assess the potential for increasing the profit margin from sawmill byproducts by integrating innovative downstream processes. The focus is on the techno-economic evaluation of an integrated site for biomass-based synthetic natural gas (bio-SNG production. The option of using the syngas in a biomass-integrated gasification combined cycle (b-IGCC for the production of electricity (instead of SNG is also considered for comparison. The process flowsheets that are used to analyze the energy and material balances are modelled in MATLAB and Simulink. A mathematical process integration model of a typical Nordic sawmill is used to analyze the effects on the energy flows in the overall site, as well as to evaluate the site economics. Different plant sizes have been considered in order to assess the economy-of-scale effect. The technical data required as input are collected from the literature and, in some cases, from experiments. The investment cost is evaluated on the basis of conducted studies, third party supplier budget quotations and in-house database information. This paper presents complete material and energy balances of the considered processes and the resulting process economics. Results show that in order for the integrated SNG production to be favored, depending on the sawmill size, a biofuel subsidy in the order of 28–52 €/MWh SNG is required.

  9. Ballistic Characterization Of A Typical Military Steel Helmet

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Maher

    2017-08-01

    Full Text Available In this study the ballistic limit of a steel helmet against a FMJ 919 mm caliber bullet is estimated. The helmet model is the typical polish helmet wz.31.The helmet material showed high strength low alloy steel material of 0.28 carbon content and 9.125 kgm2 areal density. The tensile test according to ASTM E8 showed a tensile strength of 1236.4 MPa .The average hardness value was about HV550. First shooting experiment has been executed using a 9 mm pistol based on 350 ms muzzle velocity at 5m against the simply supported helmet complete penetrations rose in this test were in the form of cracks on the helmet surface and partial penetrations were in the form of craters on the surface whose largest diameter and depth were 43 mm and 20.2 mm consequently .The second experiment was on a rifled gun arrangement 13 bullets of 919 mm caliber were shot on the examined simply supported steel helmet at a zero obliquity angle at different velocities to determine the ballistic limit velocity V50 according to MIL-STD-662F. Three major outcomes were revealed 1 the value V50 which found to be about 390 ms is higher than the one found in literature 360 ms German steel helmet model 1A1. 2 The smallest the standard deviation of the mixed results zone data the most accurate the ballistic limit is. 3Similar to the performance of blunt-ended projectiles impacting overmatching targets tD near 11 or larger It was found that the dominating failure mode of the steel helmet stuck by a hemispherical-nose projectile was plugging mode despite of having tD ratio of about 19 undermatching.

  10. Describing Speech Usage in Daily Activities in Typical Adults.

    Science.gov (United States)

    Anderson, Laine; Baylor, Carolyn R; Eadie, Tanya L; Yorkston, Kathryn M

    2016-01-01

    "Speech usage" refers to what people want or need to do with their speech to meet communication demands in life roles. The purpose of this study was to contribute to validation of the Levels of Speech Usage scale by providing descriptive data from a sample of adults without communication disorders, comparing this scale to a published Occupational Voice Demands scale and examining predictors of speech usage levels. This is a survey design. Adults aged ≥25 years without reported communication disorders were recruited nationally to complete an online questionnaire. The questionnaire included the Levels of Speech Usage scale, questions about relevant occupational and nonoccupational activities (eg, socializing, hobbies, childcare, and so forth), and demographic information. Participants were also categorized according to Koufman and Isaacson occupational voice demands scale. A total of 276 participants completed the questionnaires. People who worked for pay tended to report higher levels of speech usage than those who do not work for pay. Regression analyses showed employment to be the major contributor to speech usage; however, considerable variance left unaccounted for suggests that determinants of speech usage and the relationship between speech usage, employment, and other life activities are not yet fully defined. The Levels of Speech Usage may be a viable instrument to systematically rate speech usage because it captures both occupational and nonoccupational speech demands. These data from a sample of typical adults may provide a reference to help in interpreting the impact of communication disorders on speech usage patterns. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  11. Gender-typical olfactory regulation of sexual behavior in goldfish

    Directory of Open Access Journals (Sweden)

    Makito eKobayashi

    2014-04-01

    Full Text Available It is known that olfaction is essential for the occurrence of sexual behavior in male goldfish. Sex pheromones from ovulatory females elicit male sexual behavior, chasing and sperm releasing act. In female goldfish, ovarian prostaglandin F2α (PGF elicits female sexual behavior, egg releasing act. It has been considered that olfaction does not affect sexual behavior in female goldfish. In the present study, we reexamined the involvement of olfaction in sexual behavior of female goldfish. Olfaction was blocked in male and female goldfish by two methods: nasal occlusion (NO which blocks the reception of olfactants, and olfactory tract section (OTX which blocks transmission of olfactory information from the olfactory bulb to the telencephalon. Sexual behavior of goldfish was induced by administration of PGF to females, an established method for inducing goldfish sexual behavior in both sexes. Sexual behavior in males was suppressed by NO and OTX as previously reported because of lack of pheromone stimulation. In females, NO suppressed sexual behavior but OTX did not affect the occurrence of sexual behavior. Females treated with both NO and OTX performed sexual behavior normally. These results indicate that olfaction is essential in female goldfish to perform sexual behavior as in males but in a different manner. The lack of olfaction in males causes lack of pheromonal stimulation, resulting in no behavior elicited. Whereas the results of female experiments suggest that lack of olfaction in females causes strong inhibition of sexual behavior mediated by the olfactory pathway. Olfactory tract section is considered to block the pathway and remove this inhibition, resulting in the resumption of the behavior. By subtract sectioning of the olfactory tract, it was found that this inhibition was mediated by the medial olfactory tracts, not the lateral olfactory tracts. Thus, it is concluded that goldfish has gender-typical olfactory regulation for sexual

  12. Response of Maize Plant to Phosphorus Fertilization on Typic Distrudepts

    Directory of Open Access Journals (Sweden)

    Antonius Kasno

    2009-05-01

    Full Text Available On the acid soil, phosphorus nutrients become critical for agricultural crops growth. At the present, price of fertilizers significantly increase and fertilizers are not available. These conditions can affect on soil productivity and crop production. The objective of these research were to study the response of maize (Zea mays L. to phosphate fertilizers on Inceptisol. The research was conducted in Cicadas Village on Typic Dystrudept. Experiment was conducted in a randomized completely block design, with 8 treatments and three replications. Treatments consisted of 6 dosages of P fertilizers, which were P source is SP-36 WIKA Agro 0, 10, 20, 40, 60 and 80 kg ha-1. SP-36 and Tunisia rock phosphate (40 kg P ha-1 were used for standard. Pioneer 12 variety of maized was used as an indicator. Plot size was 5 m x 6 m and the maize was planting with distance of 75 cm x 20 cm with one seed per hole. The results showed that organic C and N, P (extracted by Bray 1, K and CEC on the soil were low. Phosphate fertilizers significantly increased which was P extracted by HCl 25% from 24 to 67 mg P 100 g-1 soil and which were extracted by Bray 1 increased from 0,87 to 63.31 mg P kg-1 soil. Phosphate fertilizers significantly increased plant height from 175.2 cm become to 221.1 cm. Plant height of maize using SP-36 WIKA Agro fertilizer (210.6 cm was similar to plant heigh using SP-36 fertilizer (213.4 cm but less height from Tunisia rock phosphate. The yield of maize on SP-36 WIKA Agro (4.94 t ha-1 were linely higher than SP-36 (4.69 t ha-1, significantly was higher than that of Tunisia rock phosphate. Maximum dosage of SP-36 fertilizer was 66.67 kg P ha-1, and optimum dosage was 42 kg P ha-1. Value of Relative Agronomic Effectiveness SP-36 WIKA Agro fertilizer was heigher than SP-36.

  13. [Investigation of typical melamine urinary stones using infrared spectra].

    Science.gov (United States)

    Si, Min-Zhen; Li, Qing-Yun; Liu, Ren-Ming; Kang, Yi-Pu; Wang, Kun-Hua; Zhang, Zhi-Guo

    2010-02-01

    A typical melamine kidney stone confirmed by some medicine expert was collected from the first people's hospital of Yunnan. The kidney stone was adequately determined by PE corporation spectra 100(with resolution of 1 cm(-1)). The stone samples for FTIR analysis were prepared using the KBr pellet technique, where 2 mg of the pretreated stone powder was mixed with 200 mg of analytical grade KBr using an agate pestle and mortar. The digital spectrum was then scanned in the mid-infrared region from 4 000 to 400 cm(-1) at room temperature. The appearing bands between 4 000 and 2 000 cm(-1) were 3 487, 3 325, 3 162 and 2 788 cm(-1), those between 1 700 and 1 000 cm(-1) were 1 694, 1 555, 1 383, 1 340, 1 189 and 1 122 cm(-1), and those between 1 000 and 400 cm(-1) were 993, 782, 748, 709, 624, 585, 565 and 476 cm(-1). It was found that the main constituent of calculi showed few comparability with cat kidney stone, which was from cats that died after consuming the contaminated food, and confirmed that these deposits were primarily composed of melamine and cyanuric acid compared to the IR spectra of calculi in literature. It was also found that the main constituent of calculi showed few comparability with popular kidney stone by comparison with the IR spectra of calculi in literature. The spectrum of calculi was 50% respectively similar with melamine and uric acid as compared with the IR spectrum. It was found that the main constituent of calculi was melamine itself and uric acid as compared with the IR spectra of calculi and melamine: (1 : 1), because the spectrum of calculi was 83. 3% similar to melamine and uric acid (1 : 1). The appearing bands of melamine and uric acid (1 : 1) between 4 000 and 2 000 cm(-1) were 3 469, 3 419, 3 333, 3 132, 3 026, 2 827 cm(-1), those between 1 700 and 1 000 cm(-1) were 1 696, 1 656, 1 555, 1 489, 1 439, 1 350, 1 311, 1 198, 1 124 and 1 028 cm(-1), and those between 1 000 and 400 cm(-1) were 993, 878, 814, 784, 745, 708, 619, 577 and

  14. Detection of plastic explosives by thermic neutron radiography

    International Nuclear Information System (INIS)

    Hacidume, Leo R.; Crispim, Verginia R.; Silva, Ademir X. da

    2000-01-01

    This work aims to demonstrate the potentiality of the neutron radiography technique, allied to the computerized tomography by transmission, to both detect and visualize plastic explosive samples in several hidden conditions, using a simple scanner as a digitalisation instrument. Each tomographic essay was obtained in the J-9 channel of the Argonauta Research Reactor of IEN/CNEN, in groups of six neutron radiographic projections, performed with an angular increment of 30 in a period of time of 30 minutes for each projection. Two groups of tomographic reconstructions were generated, distinguished by the digitalisation process of the interested lines in the reconstruction plane coming from the projection groups, utilizing a scanner and a microdensitometer, respectively. The reconstruction of the bi-dimensional image of the transverse section, in relation to this plane, was processed making use of the Image reconstruction algorithmic of an image based on the maximum entropy principle (ARIEM). From the qualitative analysis of the images, we conclude that the neutron radiographic system was able to detect the explosive sample in a satisfactory way while the quantitative analysis confirmed the application effectiveness of a scanner to acquire the projection dates whose objective is only a reconnaissance. (author)

  15. Thermic decomposition of biphenyl; Decomposition thermique du biphenyle

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-03-01

    Liquid and vapour phase pyrolysis of very pure biphenyl obtained by methods described in the text was carried out at 400 C in sealed ampoules, the fraction transformed being always less than 0.1 per cent. The main products were hydrogen, benzene, terphenyls, and a deposit of polyphenyls strongly adhering to the walls. Small quantities of the lower aliphatic hydrocarbons were also found. The variation of the yields of these products with a) the pyrolysis time, b) the state (gas or liquid) of the biphenyl, and c) the pressure of the vapour was measured. Varying the area and nature of the walls showed that in the absence of a liquid phase, the pyrolytic decomposition takes place in the adsorbed layer, and that metallic walls promote the reaction more actively than do those of glass (pyrex or silica). A mechanism is proposed to explain the results pertaining to this decomposition in the adsorbed phase. The adsorption seems to obey a Langmuir isotherm, and the chemical act which determines the overall rate of decomposition is unimolecular. (author) [French] Du biphenyle tres pur, dont la purification est decrite, est pyrolyse a 400 C en phase vapeur et en phase liquide dans des ampoules scellees sous vide, a des taux de decomposition n'ayant jamais depasse 0,1 pour cent. Les produits provenant de la pyrolyse sont essentiellement: l' hydrogene, le benzene, les therphenyles, et un depot de polyphenyles adherant fortement aux parois. En plus il se forme de faibles quantites d'hydrocarbures aliphatiques gazeux. On indique la variation des rendements des differents produits avec la duree de pyrolyse, l'etat gazeux ou liquide du biphenyle, et la pression de la vapeur. Variant la superficie et la nature des parois, on montre qu'en absence de liquide la pyrolyse se fait en phase adsorbee. La pyrolyse est plus active au contact de parois metalliques que de celles de verres (pyrex ou silice). A partir des resultats experimentaux un mecanisme de degradation du biphenyle en phase adsorbee est suggere, l'adsorption paraissant regie par l'isotherme de Langmuir, et l'acte chimique determinant la vitesse globale de la pyrolyse etant monomoleculaire en ce qui concerne le molecule de biphenyle adsorbee. (auteur)

  16. Leaching of aluminum and iron from boiler slag generated from a typical Chinese Steel Plant.

    Science.gov (United States)

    Li, Jinping; Gan, Jinhua; Li, Xianwang

    2009-07-30

    This paper presents a new way of recycling aluminum and iron in boiler slag derived from coal combustion plants, which integrates efficient extraction and reuse of the leached pellets together. The boiler slag was pelletized together with washed coal and lime prior to sintering and then was sintered at 800-1200 degrees C for different periods to produce sintered pellets for the leaching test. An elemental analysis of aqueous solutions leached by sulfuric acid was determined by EDTA-Na(2)-ZnCl(2) titration method. The components and microstructures of the samples, sintered pellets and leached residue were examined by means of XRF, XRD and SEM. XRD analysis indicates that predominate minerals such as kaolinite, quartz, calcium silicide, hematate and metakoalin exist in the boiler slag. An aluminum extraction efficiency of 86.50% was achieved. The maximum extraction efficiency of Fe was 94.60% in the same conditions of that for the maximum extraction efficiency of Al. The extraction efficiencies of Al and Fe increased with an increase in temperature, leaching time and acidity. High Al extraction efficiency was obtained for pellets with high CaO content. The final product of alumina would be used directly for the production of metallic aluminum.

  17. Efeito da adição de fonolito na sinterização de argila caulinítica Effect of phonolite addition on sintering kaolinitic clay

    Directory of Open Access Journals (Sweden)

    P. M. Andrade

    2005-12-01

    Full Text Available Este trabalho tem por objetivo avaliar o comportamento de queima de uma argila caulinítica incorporada com fonolito visando à obtenção de revestimento cerâmico prensado do tipo semiporoso. Foram preparadas composições com adição de fonolito a uma argila caulinítica nas proporções de 20 e 40% em peso. Para efeito comparativo, avaliou-se uma massa cerâmica industrial proveniente do pólo cerâmico de Santa Gertrudes. Foram preparados corpos de prova cilíndricos por prensagem uniaxial a 25 MPa para queima em temperaturas variando de 1050 a 1200 ºC. Nas amostras queimadas, foram realizados ensaios tecnológicos para determinação da retração linear e absorção de água em função da temperatura de queima. A avaliação microestrutural das composições estudadas foi realizada por difração de raios X e microscopia eletrônica de varredura. Os resultados mostraram que a adição de fonolito melhora significativamente a sinterização da argila caulinítica, sobretudo, em temperaturas acima de 1150 ºC, onde ocorre uma redução brusca da porosidade. Apesar do maior teor de óxidos alcalinos em comparação com uma massa industrial de revestimento cerâmico, as misturas argila/fonolito só alcançaram uma absorção de água de 10% , máxima para revestimentos semiporosos, em temperaturas cerca de 80 ºC superior à massa industrial.This work had as its objective to evaluate the firing behavior of a kaolinitic clay incorporated with phonolite aiming at semiporous pressed ceramic tiles. Compositions were prepared with addition of 20 and 40 wt.% of phonolite to a kaolinitic clay. For comparison, an industrial ceramic body from Santa Gertrudes, State of S. Paulo, was also evaluated. Cylindrical specimens were prepared by uniaxial pressure at 25 MPa followed by firing at temperatures varying from 1050 to 1200 ºC. The fired specimens were submitted to the following tests: linear shrinkage and water absorption as function of the firing

  18. Modeling of the non isothermal and non isobaric transformations kinetics. Application to the kaolinite de-hydroxylation and to the tri-uranium octo-oxide reduction by hydrogen

    International Nuclear Information System (INIS)

    Perrin, St.

    2002-12-01

    The aim of this work is to be able to describe transformations, occurring when solids and gases are in non isothermal and non isobaric conditions, with kinetic models. A methodology has been used. Two essential processes have to be taken into account: the germination and the growth. The germs are supposed to be formed (at constant temperature and pressure) in the grains surface with a constant velocity by surface unit, (gamma), called germination surface frequency (number of germs.m -2 .s -1 . The growth velocity is characterized by a growth surface reactivity, (phi) (in mol.m -2 .s -1 ). With an appropriate transformation model, it is possible to obtain the variations of (gamma) and (phi) in terms of the temperature and pressure which are then used in the calculation of the velocity in non isothermal and non isobaric conditions. In order to validate the developed method, two reactions have been studied. For the first one, the kaolinite de-hydroxylation, an anisotropic germination-growth model, where the step limiting the growth is a diffusion step, has been developed in order to explain the experimental kinetic curves. Nevertheless the velocity curves calculated from this model do not allow to describe the reaction for some temperature variations. This result shows the difficulty to precisely determine the germination surface frequency what induces an important approximation on the kinetic curves. The second reaction is the tri-uranium octo-oxide reduction by hydrogen. It has been shown that this reaction occurs according to three successive transformations. A kinetic model has been developed for each of these reactions considering germination as instantaneous. At last, in comparing this model with the experimental velocity curves, a very good agreement has been verified as well as for a temperature variation than for a hydrogen partial pressure change during the reaction. (O.M.)

  19. Uptake properties of Ni2+ by nCaO.Al2O3.2SiO2 (n=1-4) prepared from solid-state reaction of kaolinite and calcite.

    Science.gov (United States)

    Jha, Vinay Kumar; Kameshima, Yoshikazu; Nakajima, Akira; Okada, Kiyoshi; MacKenzie, Kenneth J D

    2005-08-31

    A series of nCaO.Al2O3.2SiO2 samples (n=1-4) were prepared by solid-state reaction of mechanochemically treated mixtures of kaolinite and calcite fired at 600-1000 degrees C for 24 h. All the samples were X-ray amorphous after firing at 600-800 degrees C but had crystallized by 900 degrees C. The main crystalline phases were anorthite (n=1), gehlenite (n=2 and 3) and larnite (n=4). The uptake of Ni2+ by nCaO.Al2O3.2SiO2 samples fired at 800 and 900 degrees C was investigated at room temperature using solutions with initial Ni2+ concentrations of 0.1-50 mmol/l. Amorphous samples (fired at 800 degrees C) showed a higher Ni2+ uptake capacity than crystalline samples (fired at 900 degrees C). Ni2+ uptake was found to increase with increasing of CaO content. Amorphous 4CaO.Al2O3.2SiO2 showed the highest Ni2+ uptake capacity (about 9 mmol/g). The Ni2+ uptake abilities of the present samples are higher than those of other materials reported in the literature. Since the sorbed Ni2+/released Ca2+ ratios of these samples are close to unity, ion replacement of Ni2+ for Ca2+ is thought to be the principal mechanism of Ni2+ uptake by the present samples.

  20. Typicality Mediates Performance during Category Verification in Both Ad-Hoc and Well-Defined Categories

    Science.gov (United States)

    Sandberg, Chaleece; Sebastian, Rajani; Kiran, Swathi

    2012-01-01

    Background: The typicality effect is present in neurologically intact populations for natural, ad-hoc, and well-defined categories. Although sparse, there is evidence of typicality effects in persons with chronic stroke aphasia for natural and ad-hoc categories. However, it is unknown exactly what influences the typicality effect in this…

  1. For Your Local Eyes Only: Culture-Specific Face Typicality Influences Perceptions of Trustworthiness.

    Science.gov (United States)

    Sofer, Carmel; Dotsch, Ron; Oikawa, Masanori; Oikawa, Haruka; Wigboldus, Daniel H J; Todorov, Alexander

    2017-08-01

    Recent findings show that typical faces are judged as more trustworthy than atypical faces. However, it is not clear whether employment of typicality cues in trustworthiness judgment happens across cultures and if these cues are culture specific. In two studies, conducted in Japan and Israel, participants judged trustworthiness and attractiveness of faces. In Study 1, faces varied along a cross-cultural dimension ranging from a Japanese to an Israeli typical face. Own-culture typical faces were perceived as more trustworthy than other-culture typical faces, suggesting that people in both cultures employ typicality cues when judging trustworthiness, but that the cues, indicative of typicality, are culture dependent. Because perceivers may be less familiar with other-culture typicality cues, Study 2 tested the extent to which they rely on available facial information other than typicality, when judging other-culture faces. In Study 2, Japanese and Israeli faces varied from either Japanese or Israeli attractive to unattractive with the respective typical face at the midpoint. For own-culture faces, trustworthiness judgments peaked around own-culture typical face. However, when judging other-culture faces, both cultures also employed attractiveness cues, but this effect was more apparent for Japanese participants. Our findings highlight the importance of culture when considering the effect of typicality on trustworthiness judgments.

  2. Exploration of Rice Husk Compost as an Alternate Organic Manure to Enhance the Productivity of Blackgram in Typic Haplustalf and Typic Rhodustalf

    Directory of Open Access Journals (Sweden)

    Subramanium Thiyageshwari

    2018-02-01

    Full Text Available The present study was aimed at using cellulolytic bacterium Enhydrobacter and fungi Aspergillus sp. for preparing compost from rice husk (RH. Further, the prepared compost was tested for their effect on blackgram growth promotion along with different levels of recommended dose of fertilizer (RDF in black soil (typic Haplustalf and red soil (typic Rhodustalf soil. The results revealed that, inoculation with lignocellulolytic fungus (LCF Aspergillus sp. @ 2% was considered as the most efficient method of composting within a short period. Characterization of composted rice husk (CRH was examined through scanning electron microscope (SEM for identifying significant structural changes. At the end of composting, N, P and K content increased with decrease in CO2 evolution, C:N and C:P ratios. In comparison to inorganic fertilization, an increase in grain yield of 16% in typic Haplustalf and 17% in typic Rhodustalf soil over 100% RDF was obtained from the integrated application of CRH@ 5 t ha−1 with 50% RDF and biofertilizers. The crude protein content was maximum with the combined application of CRH, 50% RDF and biofertilizers of 20% and 21% in typic Haplustalf and typic Rhodustalf soils, respectively. Nutrient rich CRH has proved its efficiency on crop growth and soil fertility.

  3. Shared temporoparietal dysfunction in dyslexia and typical readers with discrepantly high IQ.

    Science.gov (United States)

    Hancock, Roeland; Gabrieli, John D E; Hoeft, Fumiko

    2016-12-01

    It is currently believed that reading disability (RD) should be defined by reading level without regard to broader aptitude (IQ). There is debate, however, about how to classify individuals who read in the typical range but less well than would be expected by their higher IQ. We used functional magnetic resonance imaging (fMRI) in 49 children to examine whether those with typical, but discrepantly low reading ability relative to IQ, show dyslexia-like activation patterns during reading. Children who were typical readers with high-IQ discrepancy showed reduced activation in left temporoparietal neocortex relative to two control groups of typical readers without IQ discrepancy. This pattern was consistent and spatially overlapping with results in children with RD compared to typically reading children. The results suggest a shared neurological atypicality in regions associated with phonological processing between children with dyslexia and children with typical reading ability that is substantially below their IQ.

  4. Predictors and consequences of gender typicality: the mediating role of communality.

    Science.gov (United States)

    DiDonato, Matthew D; Berenbaum, Sheri A

    2013-04-01

    Considerable work has shown the benefits for psychological health of being gender typed (i.e., perceiving oneself in ways that are consistent with one's sex). Nevertheless, little is known about the reasons for the link. In two studies of young adults (total N = 673), we studied (1) the ways in which gender typing is predicted from gender-related interests and personal qualities, and (2) links between gender typing and adjustment (self-esteem and negative emotionality). In the first study, gender typicality was positively predicted by a variety of gender-related characteristics and by communal traits, a female-typed characteristic; gender typicality was also positively associated with adjustment. To clarify the role of communality in predicting gender typicality and its link with adjustment, we conducted a follow-up study examining both gender typicality and "university typicality." Gender typicality was again predicted by gender-related characteristics and communality, and associated with adjustment. Further, university typicality was also predicted by communality and associated with adjustment. Mediation analyses showed that feelings of communality were partly responsible for the links between gender/university typicality and adjustment. Thus, the psychological benefits suggested to accrue from gender typicality may not be specific to gender, but rather may reflect the benefits of normativity in general. These findings were discussed in relation to the broader literature on the relation between identity and adjustment.

  5. 16 CFR Figure 5 to Part 1610 - An Example of a Typical Gas Shield

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false An Example of a Typical Gas Shield 5 Figure 5 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... Example of a Typical Gas Shield ER25MR08.004 ...

  6. 16 CFR Figure 4 to Part 1610 - An Example of a Typical Indicator Finger

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false An Example of a Typical Indicator Finger 4 Figure 4 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... Example of a Typical Indicator Finger ER25MR08.003 ...

  7. 29 CFR 780.210 - The typical hatchery operations constitute “agriculture.”

    Science.gov (United States)

    2010-07-01

    ... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Agriculture as It Relates to Specific Situations Hatchery Operations § 780.210 The typical hatchery operations constitute “agriculture.” As stated in § 780.127, the typical hatchery...

  8. Gestures in Prelinguistic Turkish Children with Autism, Down Syndrome, and Typically Developing Children

    Science.gov (United States)

    Toret, Gokhan; Acarlar, Funda

    2011-01-01

    The purpose of this study was to examine gesture use in Turkish children with autism, Down syndrome, and typically developing children. Participants included 30 children in three groups: Ten children with Down syndrome, ten children with autism between 24-60 months of age, and ten typically developing children between 12-18 months of age.…

  9. Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

    Science.gov (United States)

    Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

    2011-12-01

    Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

  10. Lipreading Ability and Its Cognitive Correlates in Typically Developing Children and Children with Specific Language Impairment

    Science.gov (United States)

    Heikkilä, Jenni; Lonka, Eila; Ahola, Sanna; Meronen, Auli; Tiippana, Kaisa

    2017-01-01

    Purpose: Lipreading and its cognitive correlates were studied in school-age children with typical language development and delayed language development due to specific language impairment (SLI). Method: Forty-two children with typical language development and 20 children with SLI were tested by using a word-level lipreading test and an extensive…

  11. For your local eyes only: Culture-specific face typicality influences perceptions of trustworthiness

    NARCIS (Netherlands)

    Sofer, C.; Dotsch, R.; Oikawa, M.; Oikawa, H.; Wigboldus, D.H.J.; Todorov, A.T.

    2017-01-01

    Recent findings show that typical faces are judged as more trustworthy than atypical faces. However, it is not clear whether employment of typicality cues in trustworthiness judgment happens across cultures and if these cues are culture specific. In two studies, conducted in Japan and Israel,

  12. Health-Related Quality of Life in Children Attending Special and Typical Education Greek Schools

    Science.gov (United States)

    Papadopoulou, D.; Malliou, P.; Kofotolis, N.; Vlachopoulos, S. P.; Kellis, E.

    2017-01-01

    The purpose of this study was to examine parental perceptions about Health Related Quality of Life (HRQoL) of typical education and special education students in Greece. The Pediatric Quality of Life Inventory (PedsQL) was administered to the parents of 251 children from typical schools, 46 students attending integration classes (IC) within a…

  13. Using Typical Infant Development to Inform Music Therapy with Children with Disabilities

    Science.gov (United States)

    Wheeler, Barbara L.; Stultz, Sylvia

    2008-01-01

    This article illustrates some ways in which observations of typically-developing infants can inform music therapy and other work with children with disabilities. The research project that is described examines typical infant development with special attention to musical relatedness and communication. Videotapes of sessions centering on musical…

  14. Motor Skill Performance by Low SES Preschool and Typically Developing Children on the PDMS-2

    Science.gov (United States)

    Liu, Ting; Hoffmann, Chelsea; Hamilton, Michelle

    2017-01-01

    The purpose of this study was to compare the motor skill performance of preschool children from low socioeconomic (SES) backgrounds to their age matched typically developing peers using the Peabody Developmental Motor Scales-2 (PDMS-2). Sixty-eight children (34 low SES and 34 typically developing; ages 3-5) performed the PDMS-2. Standard scores…

  15. Development of Gender Discrimination: Effect of Sex-Typical and Sex-Atypical Toys.

    Science.gov (United States)

    Etaugh, Claire; Duits, Terri L.

    Toddlers (41 girls and 35 boys) between 18 and 37 months of age were given four gender discrimination tasks each consisting of 6 pairs of color drawings. Three of the tasks employed color drawings of preschool girls and boys holding either a sex-typical toy, a sex-atypical toy, or no toy. The fourth employed pictures of sex-typical masculine and…

  16. On the role of object knowledge in reference production : Effects of color typicality on content determination

    NARCIS (Netherlands)

    Westerbeek, H.G.W.; Koolen, R.M.F.; Maes, A.A.; Bello, Paul; Guarini, Marcello; McShane, Marjorie; Scassellati, Brian

    2014-01-01

    In two language production experiments, we investigated whether stored knowledge of the typical color of objects affects spoken reference. In experiment 1, human speakers referred to objects with colors ranging from very typical (e.g., red tomato) to very atypical (e.g., blue pepper). The

  17. Mother-Child Play: Children with Down Syndrome and Typical Development

    Science.gov (United States)

    Venuti, P.; de Falco, S.; Esposito, G.; Bornstein, Marc H.

    2009-01-01

    Child solitary and collaborative mother-child play with 21 children with Down syndrome and 33 mental-age-matched typically developing children were compared. In solitary play, children with Down syndrome showed less exploratory but similar symbolic play compared to typically developing children. From solitary to collaborative play, children with…

  18. Examining the Language Phenotype in Children with Typical Development, Specific Language Impairment, and Fragile X Syndrome

    Science.gov (United States)

    Haebig, Eileen; Sterling, Audra; Hoover, Jill

    2016-01-01

    Purpose: One aspect of morphosyntax, finiteness marking, was compared in children with fragile X syndrome (FXS), specific language impairment (SLI), and typical development matched on mean length of utterance (MLU). Method: Nineteen children with typical development (mean age = 3.3 years), 20 children with SLI (mean age = 4.9 years), and 17 boys…

  19. Effects of Biofeedback on Control and Generalization of Nasalization in Typical Speakers

    Science.gov (United States)

    Murray, Elizabeth S. Heller; Mendoza, Joseph O.; Gill, Simone V.; Perkell, Joseph S.; Stepp, Cara E.

    2016-01-01

    Purpose: The purpose of this study was to determine the effects of biofeedback on control of nasalization in individuals with typical speech. Method: Forty-eight individuals with typical speech attempted to increase and decrease vowel nasalization. During training, stimuli consisted of consonant-vowel-consonant (CVC) tokens with the center vowels…

  20. Typical and Atypical Development of Basic Numerical Skills in Elementary School

    Science.gov (United States)

    Landerl, Karin; Kolle, Christina

    2009-01-01

    Deficits in basic numerical processing have been identified as a central and potentially causal problem in developmental dyscalculia; however, so far not much is known about the typical and atypical development of such skills. This study assessed basic number skills cross-sectionally in 262 typically developing and 51 dyscalculic children in…

  1. Establishing Contextual Control over Symmetry and Asymmetry Performances in Typically Developing Children and Children with Autism

    Science.gov (United States)

    O'Connor, Jennifer; Barnes-Holmes, Yvonne; Barnes-Holmes, Dermot

    2011-01-01

    Experiments 1, 2, and 3 investigated generalized contextually controlled symmetry and asymmetry in typically developing children and children with autism. In Experiment 1, eight typically developing children demonstrated the target performances without intervention. In Experiment 2, multiple-exemplar training and the use of familiar stimuli…

  2. Impact of Typical Aging and Parkinson's Disease on the Relationship among Breath Pausing, Syntax, and Punctuation

    Science.gov (United States)

    Huber, Jessica E.; Darling, Meghan; Francis, Elaine J.; Zhang, Dabao

    2012-01-01

    Purpose: The present study examines the impact of typical aging and Parkinson's disease (PD) on the relationship among breath pausing, syntax, and punctuation. Method: Thirty young adults, 25 typically aging older adults, and 15 individuals with PD participated. Fifteen participants were age- and sex-matched to the individuals with PD.…

  3. Typicality aids search for an unspecified target, but only in identification and not in attentional guidance.

    Science.gov (United States)

    Castelhano, Monica S; Pollatsek, Alexander; Cave, Kyle R

    2008-08-01

    Participants searched for a picture of an object, and the object was either a typical or an atypical category member. The object was cued by either the picture or its basic-level category name. Of greatest interest was whether it would be easier to search for typical objects than to search for atypical objects. The answer was"yes," but only in a qualified sense: There was a large typicality effect on response time only for name cues, and almost none of the effect was found in the time to locate (i.e., first fixate) the target. Instead, typicality influenced verification time-the time to respond to the target once it was fixated. Typicality is thus apparently irrelevant when the target is well specified by a picture cue; even when the target is underspecified (as with a name cue), it does not aid attentional guidance, but only facilitates categorization.

  4. The contribution of diffusion-weighted MR imaging to distinguishing typical from atypical meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Hakyemez, Bahattin [Uludag University School of Medicine, Department of Radiology, Gorukle, Bursa (Turkey); Bursa State Hospital, Department of Radiology, Bursa (Turkey); Yildirim, Nalan; Gokalp, Gokhan; Erdogan, Cuneyt; Parlak, Mufit [Uludag University School of Medicine, Department of Radiology, Gorukle, Bursa (Turkey)

    2006-08-15

    Atypical/malignant meningiomas recur more frequently then typical meningiomas. In this study, the contribution of diffusion-weighted MR imaging to the differentiation of atypical/malignant and typical meningiomas and to the determination of histological subtypes of typical meningiomas was investigated. The study was performed prospectively on 39 patients. The signal intensity of the lesions was evaluated on trace and apparent diffusion coefficient (ADC) images. ADC values were measured in the lesions and peritumoral edema. Student's t-test was used for statistical analysis. P<0.05 was considered statistically significant. Mean ADC values in atypical/malignant and typical meningiomas were 0.75{+-}0.21 and 1.17{+-}0.21, respectively. Mean ADC values for subtypes of typical meningiomas were as follows: meningothelial, 1.09{+-}0.20; transitional, 1.19{+-}0.07; fibroblastic, 1.29{+-}0.28; and angiomatous, 1.48{+-}0.10. Normal white matter was 0.91{+-}0.10. ADC values of typical meningiomas and atypical/malignant meningiomas significantly differed (P<0.001). However, the difference between peritumoral edema ADC values was not significant (P>0.05). Furthermore, the difference between the subtypes of typical meningiomas and atypical/malignant meningiomas was significant (P<0.001). Diffusion-weighted MR imaging findings of atypical/malignant meningiomas and typical meningiomas differ. Atypical/malignant meningiomas have lower intratumoral ADC values than typical meningiomas. Mean ADC values for peritumoral edema do not differ between typical and atypical meningiomas. (orig.)

  5. Adsorption Properties of Typical Lung Cancer Breath Gases on Ni-SWCNTs through Density Functional Theory

    Directory of Open Access Journals (Sweden)

    Qianqian Wan

    2017-01-01

    Full Text Available A lot of useful information is contained in the human breath gases, which makes it an effective way to diagnose diseases by detecting the typical breath gases. This work investigated the adsorption of typical lung cancer breath gases: benzene, styrene, isoprene, and 1-hexene onto the surface of intrinsic and Ni-doped single wall carbon nanotubes through density functional theory. Calculation results show that the typical lung cancer breath gases adsorb on intrinsic single wall carbon nanotubes surface by weak physisorption. Besides, the density of states changes little before and after typical lung cancer breath gases adsorption. Compared with single wall carbon nanotubes adsorption, single Ni atom doping significantly improves its adsorption properties to typical lung cancer breath gases by decreasing adsorption distance and increasing adsorption energy and charge transfer. The density of states presents different degrees of variation during the typical lung cancer breath gases adsorption, resulting in the specific change of conductivity of gas sensing material. Based on the different adsorption properties of Ni-SWCNTs to typical lung cancer breath gases, it provides an effective way to build a portable noninvasive portable device used to evaluate and diagnose lung cancer at early stage in time.

  6. Ensemble perception of emotions in autistic and typical children and adolescents

    Directory of Open Access Journals (Sweden)

    Themelis Karaminis

    2017-04-01

    Full Text Available Ensemble perception, the ability to assess automatically the summary of large amounts of information presented in visual scenes, is available early in typical development. This ability might be compromised in autistic children, who are thought to present limitations in maintaining summary statistics representations for the recent history of sensory input. Here we examined ensemble perception of facial emotional expressions in 35 autistic children, 30 age- and ability-matched typical children and 25 typical adults. Participants received three tasks: a an ‘ensemble’ emotion discrimination task; b a baseline (single-face emotion discrimination task; and c a facial expression identification task. Children performed worse than adults on all three tasks. Unexpectedly, autistic and typical children were, on average, indistinguishable in their precision and accuracy on all three tasks. Computational modelling suggested that, on average, autistic and typical children used ensemble-encoding strategies to a similar extent; but ensemble perception was related to non-verbal reasoning abilities in autistic but not in typical children. Eye-movement data also showed no group differences in the way children attended to the stimuli. Our combined findings suggest that the abilities of autistic and typical children for ensemble perception of emotions are comparable on average.

  7. [Research on developping the spectral dataset for Dunhuang typical colors based on color constancy].

    Science.gov (United States)

    Liu, Qiang; Wan, Xiao-Xia; Liu, Zhen; Li, Chan; Liang, Jin-Xing

    2013-11-01

    The present paper aims at developping a method to reasonably set up the typical spectral color dataset for different kinds of Chinese cultural heritage in color rendering process. The world famous wall paintings dating from more than 1700 years ago in Dunhuang Mogao Grottoes was taken as typical case in this research. In order to maintain the color constancy during the color rendering workflow of Dunhuang culture relics, a chromatic adaptation based method for developping the spectral dataset of typical colors for those wall paintings was proposed from the view point of human vision perception ability. Under the help and guidance of researchers in the art-research institution and protection-research institution of Dunhuang Academy and according to the existing research achievement of Dunhuang Research in the past years, 48 typical known Dunhuang pigments were chosen and 240 representative color samples were made with reflective spectral ranging from 360 to 750 nm was acquired by a spectrometer. In order to find the typical colors of the above mentioned color samples, the original dataset was devided into several subgroups by clustering analysis. The grouping number, together with the most typical samples for each subgroup which made up the firstly built typical color dataset, was determined by wilcoxon signed rank test according to the color inconstancy index comprehensively calculated under 6 typical illuminating conditions. Considering the completeness of gamut of Dunhuang wall paintings, 8 complementary colors was determined and finally the typical spectral color dataset was built up which contains 100 representative spectral colors. The analytical calculating results show that the median color inconstancy index of the built dataset in 99% confidence level by wilcoxon signed rank test was 3.28 and the 100 colors are distributing in the whole gamut uniformly, which ensures that this dataset can provide reasonable reference for choosing the color with highest

  8. Contamination profile on typical printed circuit board assemblies vs soldering process

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Purpose – The purpose of this paper was to analyse typical printed circuit board assemblies (PCBAs) processed by reflow, wave or selective wave soldering for typical levels of process-related residues, resulting from a specific or combination of soldering processes. Typical solder flux residue...... structure was identified by Fourier transform infrared spectroscopy, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode set-up. Localized extraction of residue was carried...

  9. Prospective memory deficits in illicit polydrug users are associated with the average long-term typical dose of ecstasy typically consumed in a single session.

    Science.gov (United States)

    Gallagher, Denis T; Hadjiefthyvoulou, Florentia; Fisk, John E; Montgomery, Catharine; Robinson, Sarita J; Judge, Jeannie

    2014-01-01

    Neuroimaging evidence suggests that ecstasy-related reductions in SERT densities relate more closely to the number of tablets typically consumed per session rather than estimated total lifetime use. To better understand the basis of drug related deficits in prospective memory (p.m.) we explored the association between p.m. and average long-term typical dose and long-term frequency of use. Study 1: Sixty-five ecstasy/polydrug users and 85 nonecstasy users completed an event-based, a short-term and a long-term time-based p.m. task. Study 2: Study 1 data were merged with outcomes on the same p.m. measures from a previous study creating a combined sample of 103 ecstasy/polydrug users, 38 cannabis-only users, and 65 nonusers of illicit drugs. Study 1: Ecstasy/polydrug users had significant impairments on all p.m. outcomes compared with nonecstasy users. Study 2: Ecstasy/polydrug users were impaired in event-based p.m. compared with both other groups and in long-term time-based p.m. compared with nonillicit drug users. Both drug using groups did worse on the short-term time-based p.m. task compared with nonusers. Higher long-term average typical dose of ecstasy was associated with poorer performance on the event and short-term time-based p.m. tasks and accounted for unique variance in the two p.m. measures over and above the variance associated with cannabis and cocaine use. The typical ecstasy dose consumed in a single session is an important predictor of p.m. impairments with higher doses reflecting increasing tolerance giving rise to greater p.m. impairment.

  10. Land Cover Change Monitoring of Typical Functional Communities of Sichuan Province Based on ZY-3 Data

    Science.gov (United States)

    Li, G. M.; Li, S.; Ying, G. W.; Wu, X. P.

    2018-04-01

    According to the function, land space types are divided into key development areas, restricted development areas and forbidden development areas in Sichuan Province. This paper monitors and analyses the changes of land cover in different typical functional areas from 2010 to 2017, which based on ZY-3 high-score images data and combined with statistical yearbook and thematic data of Sichuan Province. The results show that: The land cover types of typical key development zones are mainly composed of cultivated land, forest land, garden land, and housing construction land, which accounts for the total area of land cover 87 %. The land cover types of typical restricted development zone mainly consists of forest land and grassland, which occupy 97.71 % of the total area of the surface coverage. The land cover types of the typical prohibition development zone mainly consist of forest land, grassland, desert and bared earth, which accounts for the total area of land cover 99.31 %.

  11. INVESTIGATION OF SEISMIC PERFORMANCE AND DESIGN OF TYPICAL CURVED AND SKEWED BRIDGES IN COLORADO

    Science.gov (United States)

    2018-01-15

    This report summarizes the analytical studies on the seismic performance of typical Colorado concrete bridges, particularly those with curved and skewed configurations. A set of bridge models with different geometric configurations derived from a pro...

  12. Gender Norm Salience Across Middle Schools: Contextual Variations in Associations Between Gender Typicality and Socioemotional Distress.

    Science.gov (United States)

    Smith, Danielle Sayre; Schacter, Hannah L; Enders, Craig; Juvonen, Jaana

    2018-05-01

    Youth who feel they do not fit with gender norms frequently experience peer victimization and socioemotional distress. To gauge differences between schools, the current study examined the longitudinal effects of school-level gender norm salience-a within-school association between gender typicality and peer victimization-on socioemotional distress across 26 ethnically diverse middle schools (n boys  = 2607; n girls  = 2805). Boys (but not girls) reporting lower gender typicality experienced more loneliness and social anxiety in schools with more salient gender norms, even when accounting for both individual and school level victimization. Greater gender norm salience also predicted increased depressed mood among boys regardless of gender typicality. These findings suggest particular sensitivity among boys to environments in which low gender typicality is sanctioned.

  13. METHODS OF THE APPROXIMATE ESTIMATIONS OF FATIGUE DURABILITY OF COMPOSITE AIRFRAME COMPONENT TYPICAL ELEMENTS

    Directory of Open Access Journals (Sweden)

    V. E. Strizhius

    2015-01-01

    Full Text Available Methods of the approximate estimations of fatigue durability of composite airframe component typical elements which can be recommended for application at the stage of outline designing of the airplane are generated and presented.

  14. Determinants of Occupational Gender Segregation : Work Values and Gender (A)Typical Occupational Preferences of Adolescents

    OpenAIRE

    Busch, Anne

    2011-01-01

    The study examines micro-level determinants of the occupational gender segregation, analyzing work values and their effects on gender (a)typical occupational preferences of adolescents. Human capital theory assumes that women develop higher preferences for a good work/life balance in youth, whereas men develop higher extrinsic work values. Socialization theory predicts that female adolescents form higher preferences for social work content. This gender typicality in work values is expected to...

  15. Ecosystem responses to warming and watering in typical and desert steppes

    OpenAIRE

    Zhenzhu Xu; Yanhui Hou; Lihua Zhang; Tao Liu; Guangsheng Zhou

    2016-01-01

    Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two ...

  16. A COMPARISON OF SOCIAL SKILLS OF STUDENTS WITH VISUAL IMPAIRMENTS AND TYPICALLY DEVELOPING STUDENTS

    OpenAIRE

    Demir, Fatih Emrah; Ozdemir, Selda

    2016-01-01

    The purpose of this study was to compare the social skills of students with visual impairments with social skills of typically developing students. The study groups consisted of 64 students with visual impairments and 68 typically developing students from the first to fourth grade. The Social Skills Rating System (SSRS) Teacher Form was used to evaluate the social skills of both groups. The results of the study indicated that cooperation, assertiveness, and self-control sub-scale scores and o...

  17. Study on the knowledge base system for the identification of typical target

    International Nuclear Information System (INIS)

    Qin Kai; Zhao Yingjun

    2008-01-01

    Based on the research on target knowledge base, target database, texture analysis, shape analysis, this paper proposed a new knowledge based method for typical target identification from remote sensing image. By extracting the texture characters and shape characters, joining with spatial analysis in GIS, reasoning according to the prior knowledge in the knowledge base, this method can identify and ex- tract typical target from remote sensing images. (authors)

  18. Maternal and paternal pragmatic speech directed to young children with Down syndrome and typical development

    OpenAIRE

    de Falco, Simona; Venuti, Paola; Esposito, Gianluca; Bornstein, Marc H.

    2011-01-01

    The aim of this study was to compare functional features of maternal and paternal speech directed to children with Down syndrome and developmental age-matched typically developing children. Altogether 88 parents (44 mothers and 44 fathers) and their 44 young children (22 children with Down syndrome and 22 typically developing children) participated. Parents’ speech directed to children was obtained through observation of naturalistic parent–child dyadic interactions. Verbatim transcripts of m...

  19. A Fast Implementation for the Typical Testor Property Identification Based on an Accumulative Binary Tuple

    Directory of Open Access Journals (Sweden)

    Guillermo Sanchez-Diaz

    2012-11-01

    Full Text Available In this paper, we introduce a fast implementation of the CT EXT algorithm for testor property identification, that is based on an accumulative binary tuple. The fast implementation of the CT EXT algorithm (one of the fastest algorithms reported, is designed to generate all the typical testors from a training matrix, requiring a reduced number of operations. Experimental results using this fast implementation and the comparison with other state-of-the-art algorithms that generate typical testors are presented.

  20. Avaliação da eficiência de caulinita intercalada com dimetilsulfóxido em adsorção com o Zn(II em meio aquoso: cinética do processo de adsorção Evaluation of intercaled kaolinite efficiency with dimetilsulfoxide in adsorption with Zn(II in aqueous medium: kinetics of the adsorption process

    Directory of Open Access Journals (Sweden)

    D. L. Guerra

    2008-09-01

    Full Text Available Amostras de caulinita oriundas da região do Rio Capim, estado do Pará, Brasil, foram intercaladas com dimetilsulfóxido - DMSO. As amostras de caulinita naturais e intercaladas foram utilizadas em processo de adsorção com Zn(II em meio aquoso em pH 5,0 e temperatura controlada de 298 ± 1K. As propriedades físico-químicas das amostras de caulinita foram otimizadas pelo processo de intercalação, como: área superficial de 14,74 para 91,72 m²g-1 (A1 e diâmetro de poros de 2,79 para 10,72 nm (A1. A análise dos resultados experimentais de adsorção foi feita pelos modelos de Langmuir, Temkin e Freundlich. O modelo de Langmuir apresentou melhor aproximação com os dados experimentais de adsorção. Estes resultados foram bem representados pelo modelo cinético de segunda ordem de Lagergren, com a taxa constante K2 no intervalo de 4,76x10-3 a 11,81x10-3 g(mmol.min-1 (A2. O processo de adsorção foi considerado rápido alcançando o equilíbrio em 180 min.The kaolinite clay samples from Capim River region, Pará state, Brazil, were intercalated with dimethylsulfoxide - DMSO. The natural and intercalated kaolinite were used in adsorption process with Zn(II in aqueous medium at pH 5.0 and controlled temperature of 298 ± 1K. The physical-chemical properties of kaolinite samples were optimized for the intercalation process, such as: specific area of 14.74 to 91.72 m²g-1 (A1 and pore diameter of 2.79 to 10.72 nm (A1. The adsorption experimental results were analyzed for Langmuir, Temkin and Freundlich models, the Langmuir model has been presented best approximation with experimental adsorption isotherms data. These results best fitted the second order kinetic of Lagergren model with rate constant K2, in the range of 4.76x10-3 to 11.81x10-3 g(mmol.min-1 (A2. The adsorption process was very fast and equilibrium was approached within 180 min.

  1. Frequency of celiac disease in adult patients with typical or atypical malabsorption symptoms in isfahan, iran.

    Science.gov (United States)

    Emami, Mohammad Hassan; Kouhestani, Soheila; Karimi, Somayeh; Baghaei, Abdolmahdi; Janghorbani, Mohsen; Jamali, Nahid; Gholamrezaei, Ali

    2012-01-01

    Aim. Atypical presentations of celiac disease (CD) have now been shown to be much more common than classical (typical) form. We evaluated the frequency of CD among adult patients with typical or atypical symptoms of CD. Materials and Methods. Patients referred to two outpatient gastroenterology clinics in Isfahan (IRAN) were categorized into those with typical or atypical symptoms of CD. IgA antitissue transglutaminase antibody was assessed and followed by duodenal biopsy. In patients for whom endoscopy was indicated (independent of the serology), duodenal biopsy was taken. Histopathological changes were assessed according to the Marsh classification. Results. During the study period, 151 and 173 patients with typical and atypical symptoms were evaluated (mean age = 32.8 ± 12.6 and 35.8 ± 14.8 years, 47.0% and 56.0% female, resp.). Frequency of CD in patients with typical and atypical symptoms was calculated, respectively, as 5.9% (9/151) and 1.25% (3/173) based on positive serology and pathology. The overall frequency was estimated as at least 9.2% (14/151) and 4.0% (7/173) when data of seronegative patients were also considered. Conclusions. CD is more frequent among patients with typical symptoms of malabsorption and these patients should undergo duodenal biopsy, irrespective of the serology. In patients with atypical symptoms, serological tests should be performed followed by endoscopic biopsy, and routine duodenal biopsy is recommended when endoscopic evaluation is indicated because of symptoms.

  2. The influence of gender and gender typicality on autobiographical memory across event types and age groups.

    Science.gov (United States)

    Grysman, Azriel; Fivush, Robyn; Merrill, Natalie A; Graci, Matthew

    2016-08-01

    Gender differences in autobiographical memory emerge in some data collection paradigms and not others. The present study included an extensive analysis of gender differences in autobiographical narratives. Data were collected from 196 participants, evenly split by gender and by age group (emerging adults, ages 18-29, and young adults, ages 30-40). Each participant reported four narratives, including an event that had occurred in the last 2 years, a high point, a low point, and a self-defining memory. Additionally, all participants completed self-report measures of masculine and feminine gender typicality. The narratives were coded along six dimensions-namely coherence, connectedness, agency, affect, factual elaboration, and interpretive elaboration. The results indicated that females expressed more affect, connection, and factual elaboration than males across all narratives, and that feminine typicality predicted increased connectedness in narratives. Masculine typicality predicted higher agency, lower connectedness, and lower affect, but only for some narratives and not others. These findings support an approach that views autobiographical reminiscing as a feminine-typed activity and that identifies gender differences as being linked to categorical gender, but also to one's feminine gender typicality, whereas the influences of masculine gender typicality were more context-dependent. We suggest that implicit gendered socialization and more explicit gender typicality each contribute to gendered autobiographies.

  3. Effects of temperature and mass conservation on the typical chemical sequences of hydrogen oxidation

    Science.gov (United States)

    Nicholson, Schuyler B.; Alaghemandi, Mohammad; Green, Jason R.

    2018-01-01

    Macroscopic properties of reacting mixtures are necessary to design synthetic strategies, determine yield, and improve the energy and atom efficiency of many chemical processes. The set of time-ordered sequences of chemical species are one representation of the evolution from reactants to products. However, only a fraction of the possible sequences is typical, having the majority of the joint probability and characterizing the succession of chemical nonequilibrium states. Here, we extend a variational measure of typicality and apply it to atomistic simulations of a model for hydrogen oxidation over a range of temperatures. We demonstrate an information-theoretic methodology to identify typical sequences under the constraints of mass conservation. Including these constraints leads to an improved ability to learn the chemical sequence mechanism from experimentally accessible data. From these typical sequences, we show that two quantities defining the variational typical set of sequences—the joint entropy rate and the topological entropy rate—increase linearly with temperature. These results suggest that, away from explosion limits, data over a narrow range of thermodynamic parameters could be sufficient to extrapolate these typical features of combustion chemistry to other conditions.

  4. Advanced software tool for the creation of a typical meteorological year

    International Nuclear Information System (INIS)

    Skeiker, Kamal; Ghani, Bashar Abdul

    2008-01-01

    The generation of a typical meteorological year is of great importance for calculations concerning many applications in the field of thermal engineering. In this context, method that has been proposed by Hall et al. is selected for generating typical data, and an improved criterion for final selection of typical meteorological month (TMM) was demonstrated. The final selection of the most representative year was done by examining a composite score S. The composite score was calculated as the weighed sum of the scores of the four meteorological parameters used. These parameters are air dry bulb temperature, relative humidity, wind velocity and global solar radiation intensity. Moreover, a new modern software tool using Delphi 6.0 has been developed, utilizing the Filkenstein-Schafer statistical method for the creation of a typical meteorological year for any site of concern. Whereas, an improved criterion for final selection of typical meteorological month was employed. Such tool allows the user to perform this task without an intimate knowledge of all of the computational details. The final alphanumerical and graphical results are presented on screen, and can be saved to a file or printed as a hard copy. Using this software tool, a typical meteorological year was generated for Damascus, capital of Syria, as a test run example. The data processed used were obtained from the Department of Meteorology and cover a period of 10 years (1991-2000)

  5. Frequency of Celiac Disease in Adult Patients with Typical or Atypical Malabsorption Symptoms in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hassan Emami

    2012-01-01

    Full Text Available Aim. Atypical presentations of celiac disease (CD have now been shown to be much more common than classical (typical form. We evaluated the frequency of CD among adult patients with typical or atypical symptoms of CD. Materials and Methods. Patients referred to two outpatient gastroenterology clinics in Isfahan (IRAN were categorized into those with typical or atypical symptoms of CD. IgA antitissue transglutaminase antibody was assessed and followed by duodenal biopsy. In patients for whom endoscopy was indicated (independent of the serology, duodenal biopsy was taken. Histopathological changes were assessed according to the Marsh classification. Results. During the study period, 151 and 173 patients with typical and atypical symptoms were evaluated (mean age = 32.8±12.6 and 35.8±14.8 years, 47.0% and 56.0% female, resp.. Frequency of CD in patients with typical and atypical symptoms was calculated, respectively, as 5.9% (9/151 and 1.25% (3/173 based on positive serology and pathology. The overall frequency was estimated as at least 9.2% (14/151 and 4.0% (7/173 when data of seronegative patients were also considered. Conclusions. CD is more frequent among patients with typical symptoms of malabsorption and these patients should undergo duodenal biopsy, irrespective of the serology. In patients with atypical symptoms, serological tests should be performed followed by endoscopic biopsy, and routine duodenal biopsy is recommended when endoscopic evaluation is indicated because of symptoms.

  6. Time to discontinuation of atypical versus typical antipsychotics in the naturalistic treatment of schizophrenia

    Directory of Open Access Journals (Sweden)

    Swartz Marvin

    2006-02-01

    Full Text Available Abstract Background There is an ongoing debate over whether atypical antipsychotics are more effective than typical antipsychotics in the treatment of schizophrenia. This naturalistic study compares atypical and typical antipsychotics on time to all-cause medication discontinuation, a recognized index of medication effectiveness in the treatment of schizophrenia. Methods We used data from a large, 3-year, observational, non-randomized, multisite study of schizophrenia, conducted in the U.S. between 7/1997 and 9/2003. Patients who were initiated on oral atypical antipsychotics (clozapine, olanzapine, risperidone, quetiapine, or ziprasidone or oral typical antipsychotics (low, medium, or high potency were compared on time to all-cause medication discontinuation for 1 year following initiation. Treatment group comparisons were based on treatment episodes using 3 statistical approaches (Kaplan-Meier survival analysis, Cox Proportional Hazards regression model, and propensity score-adjusted bootstrap resampling methods. To further assess the robustness of the findings, sensitivity analyses were performed, including the use of (a only 1 medication episode for each patient, the one with which the patient was treated first, and (b all medication episodes, including those simultaneously initiated on more than 1 antipsychotic. Results Mean time to all-cause medication discontinuation was longer on atypical (N = 1132, 256.3 days compared to typical antipsychotics (N = 534, 197.2 days; p Conclusion In the usual care of schizophrenia patients, time to medication discontinuation for any cause appears significantly longer for atypical than typical antipsychotics regardless of the typical antipsychotic potency level. Findings were primarily driven by clozapine and olanzapine, and to a lesser extent by risperidone. Furthermore, only clozapine and olanzapine therapy showed consistently and significantly longer treatment duration compared to perphenazine, a medium

  7. Elements of a thermic method of preparing beta-sources with fused carriers, including strontium-90; Elements d'une methode thermique de preparation de sources beta avec des entraineurs fondus, y compris le strontium-90; Osnovy termicheskogo metoda prigotovleniya beta-istochnikov s plavlennymi nositelyami, vklyuchayushchimi strontsij-90; Bases de un metodo termico de preparacion de fuentes beta con portadores fundidos, incluido el estroncio-90

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, N I; Zakharova, K P; Zimakov, P V; Kulichenko, V V

    1962-01-15

    Sources of ionizing radiation based on the radioisotope Sr{sup 90} are widely used in apparatus and systems of automatic control and regulation of industrial processes. The technology of the preparation of sources is based on dehydration of a mixture of a radioactive solution of strontium nitrate with components such as boric anhydride, silica, and alumina. Thermic treatment of the dehydrated mixture at a high temperature produces a very mobile melt. This cools to a vitreous mass containing the required quantity of the radioisotope Sr{sup 90}. The paper gives data and discusses the results of dehydration of the system SrO - B{sub 2}O{sub 3} - SiO{sub 2} within a temperature range of 100 - 1000{sup o}C and justifies the choice of the main parameters of the technological process. It summarizes a method of mounting a vitreous preparation containing the required quantity of the radioisotope Sr{sup 90} on bases of various shapes and sizes made of steel, ceramic and other materials. The authors discuss the main parameters, ensuring that various types of sources shall be reliable and safe in operation, and give data of Sr{sup 90} sources prepared by the thermic method. (author) [French] Les sources de rayonnements ionisants a base de strontium-90 trouvent une large application dans les appareils et les systemes de controle et de reglage automatique des procedes de production. Le procede de preparation des sources se fonde sur la deshydratation d'un melange compose d'une solution radioactive de nitrate de strontium et d'elements comme l'anhydride borique, la silice, l'alumine, etc. Le traitement thermique du melange deshydrate a haute temperature donne lieu a la formation d'une masse fondue tres mobile, dont le refroidissement fournit une masse vitreuse contenant la quantite requise du radioisotope {sup 59}Sr. Les auteurs citent les donnees et examinent Jes resultats d'une etude sur la deshydratation du systeme SrO - B{sub 2}O{sub 3} - SiO{sub 2} a des temperatures

  8. Study on the three-station typical network deployments of workspace Measurement and Positioning System

    Science.gov (United States)

    Xiong, Zhi; Zhu, J. G.; Xue, B.; Ye, Sh. H.; Xiong, Y.

    2013-10-01

    As a novel network coordinate measurement system based on multi-directional positioning, workspace Measurement and Positioning System (wMPS) has outstanding advantages of good parallelism, wide measurement range and high measurement accuracy, which makes it to be the research hotspots and important development direction in the field of large-scale measurement. Since station deployment has a significant impact on the measurement range and accuracy, and also restricts the use-cost, the optimization method of station deployment was researched in this paper. Firstly, positioning error model was established. Then focusing on the small network consisted of three stations, the typical deployments and error distribution characteristics were studied. Finally, through measuring the simulated fuselage using typical deployments at the industrial spot and comparing the results with Laser Tracker, some conclusions are obtained. The comparison results show that under existing prototype conditions, I_3 typical deployment of which three stations are distributed in a straight line has an average error of 0.30 mm and the maximum error is 0.50 mm in the range of 12 m. Meanwhile, C_3 typical deployment of which three stations are uniformly distributed in the half-circumference of an circle has an average error of 0.17 mm and the maximum error is 0.28 mm. Obviously, C_3 typical deployment has a higher control effect on precision than I_3 type. The research work provides effective theoretical support for global measurement network optimization in the future work.

  9. The influence of thematic congruency, typicality and divided attention on memory for radio advertisements.

    Science.gov (United States)

    Martín-Luengo, Beatriz; Luna, Karlos; Migueles, Malen

    2014-01-01

    We examined the effects of the thematic congruence between ads and the programme in which they are embedded. We also studied the typicality of the to-be-remembered information (high- and low-typicality elements), and the effect of divided attention in the memory for radio ad contents. Participants listened to four radio programmes with thematically congruent and incongruent ads embedded, and completed a true/false recognition test indicating the level of confidence in their answer. Half of the sample performed an additional task (divided attention group) while listening to the radio excerpts. In general, recognition memory was better for incongruent ads and low-typicality statements. Confidence in hits was higher in the undivided attention group, although there were no differences in performance. Our results suggest that the widespread idea of embedding ads into thematic-congruent programmes negatively affects memory for ads. In addition, low-typicality features that are usually highlighted by advertisers were better remembered than typical contents. Finally, metamemory evaluations were influenced by the inference that memory should be worse if we do several things at the same time.

  10. Celiac disease in 87 children with typical and atypical symptoms in Black Sea region of Turkey.

    Science.gov (United States)

    Dinler, Gönül; Atalay, Erdal; Kalayci, Ayhan Gazi

    2009-11-01

    Celiac disease presents with a spectrum of clinical disorders. The variety of clinical presentations largely depends on age and extraintestinal findings. This study aimed to determine typical and atypical cases according to presenting symptoms and to evaluate their biochemical and pathological parameters. Eighty-seven patients with celiac disease in our unit between 2000 and 2007 were reviewed. Their diagnosis was made by serological and histological examination. The patients were divided into two groups according to their typical or atypical symptoms. The mean age of the patients at diagnosis was 8.2 years (range, 1-18 years), but patients presenting with typical symptoms were younger than those presenting with atypical symptoms. The patients in the two groups did not differ significantly in sex, weight and height Z scores except age. Diarrhea (96.3%), abdominal distention (65.4%) and failure to thrive (60%) were the most common clinical presentations in the typical group, and short stature (62.5%) and anemia (31.2%) were the most common in the atypical group. Total/subtotal villous atrophy was significantly higher in the typical group than in the atypical group. Many children with celiac disease show an atypical form. The understanding of presentations of celiac disease may prevent delayed diagnosis. Celiac disease should be specially investigated in patients with recurrent iron deficiency anemia, short stature and autoimmune disorders.

  11. Typical Versus Atypical Anorexia Nervosa Among Adolescents: Clinical Characteristics and Implications for ICD-11.

    Science.gov (United States)

    Silén, Yasmina; Raevuori, Anu; Jüriloo, Elisabeth; Tainio, Veli-Matti; Marttunen, Mauri; Keski-Rahkonen, Anna

    2015-09-01

    There is scant research on the clinical utility of differentiating International Classification of Diseases (ICD) 10 diagnoses F50.0 anorexia nervosa (typical AN) and F50.1 atypical anorexia. We reviewed systematically records of 47 adolescents who fulfilled criteria for ICD-10 F50.0 (n = 34) or F50.1 (n = 13), assessing the impact of diagnostic subtype, comorbidity, background factors and treatment choices on recovery. Atypical AN patients were significantly older (p = 0.03), heavier (minimum body mass index 16.7 vs 15.1 kg/m(2) , p = 0.003) and less prone to comorbidities (38% vs 71%, p = 0.04) and had shorter, less intensive and less costly treatments than typical AN patients. The diagnosis of typical versus atypical AN was the sole significant predictor of treatment success: recovery from atypical AN was 4.3 times (95% confidence interval [1.1, 17.5]) as likely as recovery from typical AN. Overall, our findings indicate that a broader definition of AN may dilute the prognostic value of the diagnosis, and therefore, ICD-11 should retain its distinction between typical and atypical AN. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  12. Clinical correlates of parenting stress in children with Tourette syndrome and in typically developing children.

    Science.gov (United States)

    Stewart, Stephanie B; Greene, Deanna J; Lessov-Schlaggar, Christina N; Church, Jessica A; Schlaggar, Bradley L

    2015-05-01

    To determine the impact of tic severity in children with Tourette syndrome on parenting stress and the impact of comorbid attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) symptomatology on parenting stress in both children with Tourette syndrome and typically developing children. Children with diagnosed Tourette syndrome (n=74) and tic-free typically developing control subjects (n=48) were enrolled in a cross-sectional study. Parenting stress was greater in the group with Tourette syndrome than the typically developing group. Increased levels of parenting stress were related to increased ADHD symptomatology in both children with Tourette syndrome and typically developing children. Symptomatology of OCD was correlated with parenting stress in Tourette syndrome. Parenting stress was independent of tic severity in patients with Tourette syndrome. For parents of children with Tourette syndrome, parenting stress appears to be related to the child's ADHD and OCD comorbidity and not to the severity of the child's tic. Subthreshold ADHD symptomatology also appears to be related to parenting stress in parents of typically developing children. These findings demonstrate that ADHD symptomatology impacts parental stress both in children with and without a chronic tic disorder. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. One for all: The effect of extinction stimulus typicality on return of fear.

    Science.gov (United States)

    Scheveneels, Sara; Boddez, Yannick; Bennett, Marc Patrick; Hermans, Dirk

    2017-12-01

    During exposure therapy, patients are encouraged to approach the feared stimulus, so they can experience that this stimulus is not followed by the anticipated aversive outcome. However, patients might treat the absence of the aversive outcome as an 'exception to the rule'. This could hamper the generalization of fear reduction when the patient is confronted with similar stimuli not used in therapy. We examined the effect of providing information about the typicality of the extinction stimulus on the generalization of extinction to a new but similar stimulus. In a differential fear conditioning procedure, an animal-like figure was paired with a brief electric shock to the wrist. In a subsequent extinction phase, a different but perceptually similar animal-like figure was presented without the shock. Before testing the generalization of extinction with a third animal-like figure, participants were either instructed that the extinction stimulus was a typical or an atypical member of the animal family. The typicality instruction effectively impacted the generalization of extinction; the third animal-like figure elicited lower shock expectancies in the typical relative to the atypical group. Skin conductance data mirrored these results, but did not reach significance. These findings suggest that verbal information about stimulus typicality can be a promising adjunctive to standard exposure treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Stored object knowledge and the production of referring expressions: The case of color typicality

    Directory of Open Access Journals (Sweden)

    Hans eWesterbeek

    2015-07-01

    Full Text Available When speakers describe objects with atypical properties, do they include these properties in their referring expressions, even when that is not strictly required for unique referent identification? Based on previous work, we predict that speakers mention the color of a target object more often when the object is atypically colored, compared to when it is typical. Taking literature from object recognition and visual attention into account, we further hypothesize that this behavior is proportional to the degree to which a color is atypical, and whether color is a highly diagnostic feature in the referred-to object's identity. We investigate these expectations in two language production experiments, in which participants referred to target objects in visual contexts. In Experiment 1, we find a strong effect of color typicality: less typical colors for target objects predict higher proportions of referring expressions that include color. In Experiment 2 we manipulated objects with more complex shapes, for which color is less diagnostic, and we find that the color typicality effect is moderated by color diagnosticity: it is strongest for high-color-diagnostic objects (i.e., objects with a simple shape. These results suggest that the production of atypical color attributes results from a contrast with stored knowledge, an effect which is stronger when color is more central to object identification. Our findings offer evidence for models of reference production that incorporate general object knowledge, in order to be able to capture these effects of typicality on determining the content of referring expressions.

  15. Uncinate fasciculus fractional anisotropy correlates with typical use of reappraisal in women but not men.

    Science.gov (United States)

    Zuurbier, Lisette A; Nikolova, Yuliya S; Ahs, Fredrik; Hariri, Ahmad R

    2013-06-01

    Emotion regulation refers to strategies through which individuals influence their experience and expression of emotions. Two typical strategies are reappraisal, a cognitive strategy for reframing the context of an emotional experience, and suppression, a behavioral strategy for inhibiting emotional responses. Functional neuroimaging studies have revealed that regions of the prefrontal cortex modulate amygdala reactivity during both strategies, but relatively greater downregulation of the amygdala occurs during reappraisal. Moreover, these studies demonstrated that engagement of this modulatory circuitry varies as a function of gender. The uncinate fasciculus is a major structural pathway connecting regions of the anterior temporal lobe, including the amygdala to inferior frontal regions, especially the orbitofrontal cortex. The objective of the current study was to map variability in the structural integrity of the uncinate fasciculus onto individual differences in self-reported typical use of reappraisal and suppression. Diffusion tensor imaging was used in 194 young adults to derive regional fractional anisotropy values for the right and left uncinate fasciculus. All participants also completed the Emotion Regulation Questionnaire. In women but not men, self-reported typical reappraisal use was positively correlated with fractional anisotropy values in a region of the left uncinate fasciculus within the orbitofrontal cortex. In contrast, typical use of suppression was not significantly correlated with fractional anisotropy in any region of the uncinate fasciculus in either men or women. Our data suggest that in women typical reappraisal use is specifically related to the integrity of white matter pathways linking the amygdala and prefrontal cortex.

  16. Comparing Levels of Mastery Motivation in Children with Cerebral Palsy (CP) and Typically Developing Children.

    Science.gov (United States)

    Salavati, Mahyar; Vameghi, Roshanak; Hosseini, Seyed Ali; Saeedi, Ahmad; Gharib, Masoud

    2018-02-01

    The present study aimed to compare motivation in school-age children with CP and typically developing children. 229 parents of children with cerebral palsy and 212 parents of typically developing children participated in the present cross sectional study and completed demographic and DMQ18 forms. The rest of information was measured by an occupational therapist. Average age was equal to 127.12±24.56 months for children with cerebral palsy (CP) and 128.08±15.90 for typically developing children. Independent t-test used to compare two groups; and Pearson correlation coefficient by SPSS software applied to study correlation with other factors. There were differences between DMQ subscales of CP and typically developing groups in terms of all subscales ( P Manual ability classification system (r=-0.782, P<0.001) and cognitive impairment (r=-0.161, P<0.05). Children with CP had lower mastery motivation than typically developing children. Rehabilitation efforts should take to enhance motivation, so that children felt empowered to do tasks or practices.

  17. Dysfunctional metacognition and drive for thinness in typical and atypical anorexia nervosa.

    Science.gov (United States)

    Davenport, Emily; Rushford, Nola; Soon, Siew; McDermott, Cressida

    2015-01-01

    Anorexia nervosa is complex and difficult to treat. In cognitive therapies the focus has been on cognitive content rather than process. Process-oriented therapies may modify the higher level cognitive processes of metacognition, reported as dysfunctional in adult anorexia nervosa. Their association with clinical features of anorexia nervosa, however, is unclear. With reclassification of anorexia nervosa by DSM-5 into typical and atypical groups, comparability of metacognition and drive for thinness across groups and relationships within groups is also unclear. Main objectives were to determine whether metacognitive factors differ across typical and atypical anorexia nervosa and a non-clinical community sample, and to explore a process model by determining whether drive for thinness is concurrently predicted by metacognitive factors. Women receiving treatment for anorexia nervosa (n = 119) and non-clinical community participants (n = 100), aged between 18 and 46 years, completed the Eating Disorders Inventory (3(rd) Edition) and Metacognitions Questionnaire (Brief Version). Body Mass Index (BMI) of 18.5 kg/m(2) differentiated between typical (n = 75) and atypical (n = 44) anorexia nervosa. Multivariate analyses of variance and regression analyses were conducted. Metacognitive profiles were similar in both typical and atypical anorexia nervosa and confirmed as more dysfunctional than in the non-clinical group. Drive for thinness was concurrently predicted in the typical patients by the metacognitive factors, positive beliefs about worry, and need to control thoughts; in the atypical patients by negative beliefs about worry and, inversely, by cognitive self-consciousness, and in the non-clinical group by cognitive self-consciousness. Despite having a healthier weight, the atypical group was as severely affected by dysfunctional metacognitions and drive for thinness as the typical group. Because metacognition concurrently predicted drive for thinness

  18. Comparison of mammographic and sonographic findings in typical and atypical medullary carcinomas of the breast

    International Nuclear Information System (INIS)

    Yilmaz, E.; Lebe, B.; Balci, P.; Sal, S.; Canda, T.

    2002-01-01

    AIM: The aim of this study was to describe the contribution of mammographic and sonographic findings to the discrimination of typical and atypical histopathologic groups of medullary carcinomas of the breast. MATERIALS AND METHODS: Imaging findings were retrospectively assessed in 33 women with medullary carcinomas (15 typical medullary carcinomas and 18 atypical medullary carcinomas) identified during pre-operative mammography. Twenty-nine of these women also had ultrasound and these findings were reviewed. RESULTS: Mammography showed a well circumscribed mass in 10 of the 15 (67%) typical medullary carcinomas and in four of the 17 (24%) atypical medullary carcinomas (P < 0.02). One small tumour in a woman with atypical medullary carcinoma was missed on mammography and was shown only on sonography. Sonographically, an irregular margin surrounding the whole mass or part of it was seen in three out of 14 (21%) patients with typical medullary carcinoma and in nine out of 15 (60%) patients with atypical medullary carcinomas (P < 0.05). Posterior acoustic shadowing was more often observed in the typical medullary carcinoma group than in atypical medullary carcinoma and the difference was found to be statistically significant (P < 0.05). None of the other mammographic and sonographic findings were sufficiently characteristic to allow for a differentiation between two groups. CONCLUSION: When typical medullary carcinomas were compared with atypical medullary carcinomas according to imaging features, they tended to be well circumscribed masses on both mammography and sonography, and a posterior acoustic shadow was not found on sonography. However, the imaging findings in these two subgroups often resembled each other and histopathology will always be required to confirm the diagnosis. Yilmaz, E. et al. (2002)

  19. Comparison of mammographic and sonographic findings in typical and atypical medullary carcinomas of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, E.; Lebe, B.; Balci, P.; Sal, S.; Canda, T

    2002-07-01

    AIM: The aim of this study was to describe the contribution of mammographic and sonographic findings to the discrimination of typical and atypical histopathologic groups of medullary carcinomas of the breast. MATERIALS AND METHODS: Imaging findings were retrospectively assessed in 33 women with medullary carcinomas (15 typical medullary carcinomas and 18 atypical medullary carcinomas) identified during pre-operative mammography. Twenty-nine of these women also had ultrasound and these findings were reviewed. RESULTS: Mammography showed a well circumscribed mass in 10 of the 15 (67%) typical medullary carcinomas and in four of the 17 (24%) atypical medullary carcinomas (P < 0.02). One small tumour in a woman with atypical medullary carcinoma was missed on mammography and was shown only on sonography. Sonographically, an irregular margin surrounding the whole mass or part of it was seen in three out of 14 (21%) patients with typical medullary carcinoma and in nine out of 15 (60%) patients with atypical medullary carcinomas (P < 0.05). Posterior acoustic shadowing was more often observed in the typical medullary carcinoma group than in atypical medullary carcinoma and the difference was found to be statistically significant (P < 0.05). None of the other mammographic and sonographic findings were sufficiently characteristic to allow for a differentiation between two groups. CONCLUSION: When typical medullary carcinomas were compared with atypical medullary carcinomas according to imaging features, they tended to be well circumscribed masses on both mammography and sonography, and a posterior acoustic shadow was not found on sonography. However, the imaging findings in these two subgroups often resembled each other and histopathology will always be required to confirm the diagnosis. Yilmaz, E. et al. (2002)

  20. Segmental omental infarction in childhood: a typical case diagnosed by CT allowing successful conservative treatment

    International Nuclear Information System (INIS)

    Coulier, Bruno

    2006-01-01

    Segmental omental infarction (SOI) is an uncommon cause of right lower quadrant pain in children that is often misdiagnosed as appendicitis. During the last decade, imaging findings of SOI have proved to be sufficiently typical to avoid unnecessary surgery in the majority of reported adult patients. The condition has a spontaneous favourable evolution under medical treatment. In children the surgical option remains controversial. We report a typical case of SOI in a 10-year-old boy. The diagnosis was suspected by sonography, unambiguously confirmed by multidetector CT and successfully treated conservatively. This report emphasizes the use of CT in selected acute abdominal situations, peculiarly in obese children, to avoid unnecessary surgery. (orig.)

  1. Profitability of labour factor in the typical dairy farms in the world

    Directory of Open Access Journals (Sweden)

    Andrzej Parzonko

    2009-01-01

    Full Text Available The main purpose of the article was to analyse the productivity and profitability of labour factor and to present asset endowments of the typical dairy farms distinguished within IFCN (International Farm Comparison Network. Among analysed 103 typical dairy farms from 34 countries, the highest net dairy farm profit characterised large farms from USA, Australia and New Zealand. Those farms generated also significantly higher profit per working hour then the potential wages that could be earned outside the farm. The highest assets value per 100 kg of produced milk characterised European farms (especially with low production scale.

  2. Summary of typical routine maintenance activities at Tokai Reprocessing Plant. Supplement (March, 2002)

    International Nuclear Information System (INIS)

    2002-03-01

    Typical maintenance activities, such as replacement of worn out parts and cleaning of filter elements, routinely performed during steady operation are summarized. [The Summary of Typical Routine Maintenance Activities at Tokai Reprocessing Plant] (JNC TN 8450 2001-006) was already prepared in September, 2001. The purpose of this summary is to give elementary understanding on these activities to people who are responsible for explanation them to the public. At this time, the same kind of summary is prepared as a supplement of the previous one. (author)

  3. SIZING AND COSTING OPTIMISATION OF A TYPICAL WIND/PV HYBRID ELECTRICITY GENERATION SYSTEM FOR A TYPICAL RESIDENTIAL BUILDING IN URBAN ARMIDALE NSW, AUSTRALIA

    Directory of Open Access Journals (Sweden)

    Yasser Maklad

    2014-04-01

    Full Text Available This study investigates the wind and solar electricity generation availability and potentiality for residential buildings in Armidale NSW, Australia. The main purpose of this study is to design an appropriate wind-PV hybrid system to cover the electricity consumption of typical residential buildings of various occupancy rates and relevant various average electrical daily consumption. In order to do achieve that, monthly average solar irradiance monthly average wind speed historical data observed at weather station belongs to the Australian bureau of meteorology in Armidale town over a fourteen years period from 1997–2010. Simulation of solar photovoltaic panels and wind turbines were conducted to obtain the optimal hybrid system sizing and best efficient with lowest cost. Correlations between the solar and wind power data were carried out on an hourly, daily, and monthly basis. It is shown that the hybrid system can be applied for the efficient and economic utilization of wind and solar renewable energy sources.

  4. Typical and atypical (cerebral palsy) development of unimanual and bimanual grasp planning

    NARCIS (Netherlands)

    Janssen, L.; Steenbergen, B.

    2011-01-01

    In the present study we tested 13 children with cerebral palsy (CP) and 24 typically developing children (7-12 years old) in a unimanual and bimanual motor planning task. We focused on two research questions: (1) How does motor planning develop in children with and without CP? and (2) Is motor

  5. Social-Emotional Inhibition of Return in Children with Autism Spectrum Disorder versus Typical Development

    Science.gov (United States)

    Antezana, Ligia; Mosner, Maya G.; Troiani, Vanessa; Yerys, Benjamin E.

    2016-01-01

    In typical development there is a bias to orient visual attention to social information. Children with ASD do not reliably demonstrate this bias, and the role of attention orienting has not been well studied. We examined attention orienting via the inhibition of return (IOR) mechanism in a spatial cueing task using social-emotional cues; we…

  6. Bridging the Gaps in the Study of Typical and Atypical Cognitive Development: A Commentary

    Science.gov (United States)

    Graham, Susan A.; Madigan, Sheri

    2016-01-01

    The articles in this special issue of the "Journal of Cognition and Development" examine the cognitive development of children who are following typical and atypical developmental pathways. The articles offer a mixture of theory-based considerations, reviews of the literature, and new empirical data addressing fundamental aspects of…

  7. Parenting a Child with ASD: Comparison of Parenting Style between ASD, Anxiety, and Typical Development

    Science.gov (United States)

    Ventola, Pamela; Lei, Jiedi; Paisley, Courtney; Lebowitz, Eli; Silverman, Wendy

    2017-01-01

    Parenting children with ASD has a complex history. Given parents' increasingly pivotal role in children's treatment, it is critical to consider parental style and behaviours. This study (1) compares parenting style of parents of children with ASD, parents of children with anxiety disorders, and parents of typically developing (TD) children and (2)…

  8. Guiding role of typical cases in clinical training for ophthalmology professional degree graduate students

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2014-05-01

    Full Text Available With the change of the concept of graduate enrollment, the recruiting proportion of clinical medicine professional degree graduate students is more and more, and the training of professional degree graduate students is increasingly focusing on practical. In our experience in clinical training for ophthalmology professional degree graduate students, increasing the ward clinical practice time is important. For particular emphasis on the guiding role of the typical cases, each professional group combined their professional characteristics of the typical cases to instruct the graduate students, training their clinical diagnosis and treatment ability, training their microsurgical techniques. From clinical medical writing, record summary, literature review, professional degree graduate students could expand their knowledge structure, practice their thesis writing ability. Based on the typical cases, expansion of knowledge coverage, they could improve the ability of diagnosis and treatment for special disease cases. In this rigorous training system, professional degree graduate students can learn by analogy, and focus on typical cases to get the most intuitive panoramic understanding of the diseases, with a minimum of time to master the most clinical knowledge, to enrich clinical experience, and to lay the foundation for future work in the assessment.

  9. Swedish Upper Secondary Students' Perspectives on the Typical Mathematics Lesson

    Science.gov (United States)

    Andrews, Paul; Larson, Niclas

    2017-01-01

    This paper presents a group interview study of Swedish upper secondary students' perspectives on the typical mathematics lesson. Students, from four demographically different schools, constructed a collective synthesis of their many years' experience of mathematics classrooms. Transcriptions were subjected to a constant comparison analysis, which…

  10. Contribution of milk production to global greenhouse gas emissions. An estimation based on typical farms.

    Science.gov (United States)

    Hagemann, Martin; Ndambi, Asaah; Hemme, Torsten; Latacz-Lohmann, Uwe

    2012-02-01

    Studies on the contribution of milk production to global greenhouse gas (GHG) emissions are rare (FAO 2010) and often based on crude data which do not appropriately reflect the heterogeneity of farming systems. This article estimates GHG emissions from milk production in different dairy regions of the world based on a harmonised farm data and assesses the contribution of milk production to global GHG emissions. The methodology comprises three elements: (1) the International Farm Comparison Network (IFCN) concept of typical farms and the related globally standardised dairy model farms representing 45 dairy regions in 38 countries; (2) a partial life cycle assessment model for estimating GHG emissions of the typical dairy farms; and (3) standard regression analysis to estimate GHG emissions from milk production in countries for which no typical farms are available in the IFCN database. Across the 117 typical farms in the 38 countries analysed, the average emission rate is 1.50 kg CO(2) equivalents (CO(2)-eq.)/kg milk. The contribution of milk production to the global anthropogenic emissions is estimated at 1.3 Gt CO(2)-eq./year, accounting for 2.65% of total global anthropogenic emissions (49 Gt; IPCC, Synthesis Report for Policy Maker, Valencia, Spain, 2007). We emphasise that our estimates of the contribution of milk production to global GHG emissions are subject to uncertainty. Part of the uncertainty stems from the choice of the appropriate methods for estimating emissions at the level of the individual animal.

  11. Spontaneous Lexical Alignment in Children with an Autistic Spectrum Disorder and Their Typically Developing Peers

    Science.gov (United States)

    Branigan, Holly P.; Tosi, Alessia; Gillespie-Smith, Karri

    2016-01-01

    It is well established that adults converge on common referring expressions in dialogue, and that such lexical alignment is important for successful and rewarding communication. The authors show that children with an autistic spectrum disorder (ASD) and chronological- and verbal-age-matched typically developing (TD) children also show spontaneous…

  12. Computed tomography derived fractional flow reserve testing in stable patients with typical angina pectoris

    DEFF Research Database (Denmark)

    Møller Jensen, Jesper; Erik Bøtker, Hans; Norling Mathiassen, Ole

    2017-01-01

    Aims: To assess the use of downstream coronary angiography (ICA) and short-term safety of frontline coronary CT angiography (CTA) with selective CT-derived fractional flow reserve (FFRCT) testing in stable patients with typical angina pectoris. Methods and results: Between 1 January 2016 and 30 J...... of safe cancellation of planned ICAs....

  13. Recall Memory in Children with Down Syndrome and Typically Developing Peers Matched on Developmental Age

    Science.gov (United States)

    Milojevich, H.; Lukowski, A.

    2016-01-01

    Background: Whereas research has indicated that children with Down syndrome (DS) imitate demonstrated actions over short delays, it is presently unknown whether children with DS recall information over lengthy delays at levels comparable with typically developing (TD) children matched on developmental age. Method: In the present research, 10…

  14. Bridge Building and Other Possible Metaphors for Patching over Discrepancies between Typical and Atypical Development

    Science.gov (United States)

    Chandler, Michael

    2016-01-01

    The next several pages are intended as a "Commentary" on the six target articles bundled together as a Special Issue of the "Journal of Cognition and Development"--literature reviews and research reports all intended to "build bridges" between the study of cognitive development in typical and atypical populations.

  15. Severity of Emotional and Behavioral Problems among Poor and Typical Readers.

    Science.gov (United States)

    Arnold, Elizabeth Mayfield; Goldston, David B.; Walsh, Adam K.; Reboussin, Beth A.; Daniel, Stephanie Sergent; Hickman, Enith; Wood, Frank B.

    2005-01-01

    The purpose of this study was to examine the severity of behavioral and emotional problems among adolescents with poor and typical single word reading ability (N = 188) recruited from public schools and followed for a median of 2.4 years. Youth and parents were repeatedly assessed to obtain information regarding the severity and course of symptoms…

  16. Basic Auditory Processing Skills and Phonological Awareness in Low-IQ Readers and Typically Developing Controls

    Science.gov (United States)

    Kuppen, Sarah; Huss, Martina; Fosker, Tim; Fegan, Natasha; Goswami, Usha

    2011-01-01

    We explore the relationships between basic auditory processing, phonological awareness, vocabulary, and word reading in a sample of 95 children, 55 typically developing children, and 40 children with low IQ. All children received nonspeech auditory processing tasks, phonological processing and literacy measures, and a receptive vocabulary task.…

  17. Adolescent Risk Behaviors: Studying Typical and Atypical Individuals via Multidimensional Scaling Profile Analysis

    Science.gov (United States)

    Dong, Yang; Ding, Cody

    2012-01-01

    Within the framework of problem behavior theory, the purpose of this study was to examine risk behavior profiles of typical and atypical adolescents and the differential outcomes of well-beings for these individuals in the United States. Based on the data from the survey of Health Behavior of School-Aged Children by World Health Organization,…

  18. Of tissue blocks and higher anatomy: A typical day in the life of a ...

    African Journals Online (AJOL)

    succumb, sleep the only respite life has gifted me. Tomorrow shall be yet another day…yet another opportunity to learn. It starts as a typical Monday... all Mondays do - the frantic typing that fills the air, reminiscent of a typing press. Be it a literature review or the presentation for the afternoon class, the innocent bystander may ...

  19. Comparison of Endoscopic and Histological Findings between Typical and Atypical Celiac Disease in Children.

    Science.gov (United States)

    Semwal, Pooja; Gupta, Raj Kumar; Sharma, Rahul; Garg, Kapil

    2018-04-01

    Celiac disease is a common non-communicable disease with varied presentations. Purpose of this study was to find the duodeno-endoscopic features in celiac disease and to compare duodeno-endoscopic and histological findings between typical and atypical celiac disease in children. Hospital based observational study was conducted at Sir Padampat Mother and Child Health Institute, Jaipur from June 2015 to May 2016. Patients were selected and divided in two groups- typical and atypical celiac disease based upon the presenting symptoms. Upper gastrointestinal endoscopy and duodenal biopsy was performed for serology positive patients. Results were analysed using appropriate statistical test of significance. Out of 101 enrolled patients, 47.5% were male. Age ranged from 1 to 18 years. Study showed that 54.5% were typical and 45.5% were atypical. Patients presenting with atypical symptoms were predominantly of older age group. On endoscopy, scalloping, mosaic pattern, reduced fold height and absent fold height; and in histology, advanced Marsh stage were significantly higher in the typical group. Awareness of atypical presentations as well as duodeno-endoscopic features may have considerable practical importance for the diagnosis of celiac disease in children. Scalloping, mosaic pattern, reduced fold height and nodularity are main endoscopic markers of celiac disease in children. Endoscopic markers of duodenal mucosa may be important in early diagnosis of celiac disease, in children subjected to endoscopy for atypical presentations or indication other than suspected celiac disease.

  20. Textese and use of texting by children with typical language development and Specific Language Impairment

    NARCIS (Netherlands)

    Blom, E.; van Dijk, C.; Vasić, N.; van Witteloostuijn, M.; Avrutin, S.

    The purpose of this study was to investigate texting and textese, which is the special register used for sending brief text messages, across children with typical development (TD) and children with Specific Language Impairment (SLI). Using elicitation techniques, texting and spoken language messages

  1. Typical Plan : The Architecture of Labor and the Space of Production

    NARCIS (Netherlands)

    Marullo, F.

    2014-01-01

    In a short essay dealing with the repetitive homogeneity of the Manhattan’s office layouts, Rem Koolhaas defined the term Typical Plan as one of the purest American architectural archetypes. A plan stripped of all its qualities and reduced to a calculated relation between discreet standardised

  2. The Readiness of Typical Student in Communication By Using Sign Language in Hearing Impairment Integration Programe

    Directory of Open Access Journals (Sweden)

    Mohd Hanafi Mohd Yasin

    2018-05-01

    Full Text Available This research is regarding the readiness of typical student in communication by using sign language in Hearing Impairment Integration Programme. There were 60 typical students from a Special Education Integration Programme of secondary school in Malacca were chosen as research respondents. The instrument of the research was a set of questionnaire which consisted of four parts, namely Student’s demography (Part A, Student’s knowledge (Part B, Student’s ability to communicate (Part C and Student’s interest to communicate (Part D. The questionnaire was adapted from the research of Asnul Dahar and Rabiah's 'The Readiness of Students in Following Vocational Subjects at Jerantut District, Rural Secondary School in Pahang'.  Descriptive analysis was used to analysis the data. Mean score was used to determine the level of respondents' perception of each question. The findings showed a positive relationship between typical students towards communication medium by using sign language. Typical students were seen to be interested in communicating using sign language and were willing to attend the Sign Language class if offered.

  3. Comparison with the Typical College Student Predicts Graduation When Identity Is Uncertain

    Science.gov (United States)

    Lane, David J.

    2017-01-01

    This study investigated the effect of personal identity and social comparison on college graduation. First-year college students completed an online survey measuring exploration and commitment to personal identity and perceptions of the prototypical student. Those who perceived the typical student as favorable but dissimilar to themselves had the…

  4. Ex-plant consequence assessment for NUREG-1150: models, typical results, uncertainties

    International Nuclear Information System (INIS)

    Sprung, J.L.

    1988-01-01

    The assessment of ex-plant consequences for NUREG-1150 source terms was performed using the MELCOR Accident Consequence Code System (MACCS). This paper briefly discusses the following elements of MACCS consequence calculations: input data, phenomena modeled, computational framework, typical results, controlling phenomena, and uncertainties. Wherever possible, NUREG-1150 results will be used to illustrate the discussion. 28 references

  5. The Relationship between Intolerance of Uncertainty, Sensory Sensitivities, and Anxiety in Autistic and Typically Developing Children

    Science.gov (United States)

    Neil, Louise; Olsson, Nora Choque; Pellicano, Elizabeth

    2016-01-01

    Guided by a recent theory that proposes fundamental differences in how autistic individuals deal with uncertainty, we investigated the extent to which the cognitive construct "intolerance of uncertainty" and anxiety were related to parental reports of sensory sensitivities in 64 autistic and 85 typically developing children aged…

  6. Word Problem Solving of Students with Autistic Spectrum Disorders and Students with Typical Development

    Science.gov (United States)

    Bae, Young Seh

    2013-01-01

    Mathematical Word Problem Solving of Students with Autistic Spectrum Disorders and Students with Typical Development Young Seh Bae This study investigated mathematical word problem solving and the factors associated with the solution paths adopted by two groups of participants (N=40), students with autism spectrum disorders (ASDs) and typically…

  7. 42 CFR 137.294 - What is the typical IHS environmental review process for construction projects?

    Science.gov (United States)

    2010-10-01

    ... SELF-GOVERNANCE Construction Nepa Process § 137.294 What is the typical IHS environmental review... impact on the environment, and therefore do not require environmental impact statements (EIS). Under current IHS procedures, an environmental review is performed on all construction projects. During the IHS...

  8. Adjunctive Treatment of Acute Mania with Risperidone versus Typical Antipsychotics: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Jui-Hsiu Tsai

    2005-12-01

    Full Text Available Few studies have directly compared atypical antipsychotics (e.g. risperidone with typical antipsychotics as adjunctive therapy in patients hospitalized for acute mania, especially during a lengthy hospital stay. Our retrospective, case-controlled study is a chart review of 64 patients with Diagnostic and Statistical Manual of Mental Disorders, 4th edition, defined bipolar I disorder (current episode, mania. Patients were divided into two groups according to the adjunctive medications used: the risperidone group (mood stabilizers plus risperidone and the control group (mood stabilizers plus typical antipsychotics. Outcome at discharge, medications, adverse drug effects, and length of hospital stay were compared between groups, controlling for gender, age, number of prior admissions, and duration of illness. Results indicated no statistically significant differences between groups in the controlled factors, Global Assessment of Functioning and Clinical Global Impression-Improvement scores, and adverse drug events. Patients in the risperidone group used significantly lower doses of trihexyphenidyl than those in the control group (p < 0.05. Patients treated with risperidone had a shorter hospital stay than those treated with typical antipsychotics (p < 0.01. In conclusion, antipsychotics are effective as adjunctive agents in the treatment of acute mania. The use of risperidone, in particular, decreases the need for anticholinergics and may lead to a shorter hospital stay compared with typical antipsychotics.

  9. Maternal Support for Autonomy: Relationships with Persistence for Children with Down Syndrome and Typically Developing Children

    Science.gov (United States)

    Gilmore, Linda; Cuskelly, Monica; Jobling, Anne; Hayes, Alan

    2009-01-01

    Maternal behaviors and child mastery behaviors were examined in 25 children with Down syndrome and 43 typically developing children matched for mental age (24-36 months). During a shared problem-solving task, there were no group differences in maternal directiveness or support for autonomy, and mothers in the two groups used similar verbal…

  10. Effects of biochar addition on evaporation in the five typical Loess Plateau soils

    Science.gov (United States)

    Soil evaporation is the main route of soil moisture loss and often exceeds precipitation in the arid and semi-arid regions of the Loess Plateau. This study was conducted to determine whether biochar addition could reduce soil evaporation in drylands. We measured the evaporative loss in five typical ...

  11. Modulation of Attentional Blink with Emotional Faces in Typical Development and in Autism Spectrum Disorders

    Science.gov (United States)

    Yerys, Benjamin E.; Ruiz, Ericka; Strang, John; Sokoloff, Jennifer; Kenworthy, Lauren; Vaidya, Chandan J.

    2013-01-01

    Background: The attentional blink (AB) phenomenon was used to assess the effect of emotional information on early visual attention in typically developing (TD) children and children with autism spectrum disorders (ASD). The AB effect is the momentary perceptual unawareness that follows target identification in a rapid serial visual processing…

  12. A Hybrid Method for Generation of Typical Meteorological Years for Different Climates of China

    Directory of Open Access Journals (Sweden)

    Haixiang Zang

    2016-12-01

    Full Text Available Since a representative dataset of the climatological features of a location is important for calculations relating to many fields, such as solar energy system, agriculture, meteorology and architecture, there is a need to investigate the methodology for generating a typical meteorological year (TMY. In this paper, a hybrid method with mixed treatment of selected results from the Danish method, the Festa-Ratto method, and the modified typical meteorological year method is proposed to determine typical meteorological years for 35 locations in six different climatic zones of China (Tropical Zone, Subtropical Zone, Warm Temperate Zone, Mid Temperate Zone, Cold Temperate Zone and Tibetan Plateau Zone. Measured weather data (air dry-bulb temperature, air relative humidity, wind speed, pressure, sunshine duration and global solar radiation, which cover the period of 1994–2015, are obtained and applied in the process of forming TMY. The TMY data and typical solar radiation data are investigated and analyzed in this study. It is found that the results of the hybrid method have better performance in terms of the long-term average measured data during the year than the other investigated methods. Moreover, the Gaussian process regression (GPR model is recommended to forecast the monthly mean solar radiation using the last 22 years (1994–2015 of measured data.

  13. Social Analogical Reasoning in School-Aged Children with Autism Spectrum Disorder and Typically Developing Peers

    Science.gov (United States)

    Green, Adam E.; Kenworthy, Lauren; Gallagher, Natalie M.; Antezana, Ligia; Mosner, Maya G.; Krieg, Samantha; Dudley, Katherina; Ratto, Allison; Yerys, Benjamin E.

    2017-01-01

    Analogical reasoning is an important mechanism for social cognition in typically developing children, and recent evidence suggests that some forms of analogical reasoning may be preserved in autism spectrum disorder. An unanswered question is whether children with autism spectrum disorder can apply analogical reasoning to social information. In…

  14. Theory of Mind and Children's Trait Attributions about Average and Typically Stigmatized Peers

    Science.gov (United States)

    Lapan, Candace; Boseovski, Janet J.

    2016-01-01

    Previous research indicates that children hold negative beliefs about peers with foreign accents, physical disabilities, and people who are obese. The current study examined skills associated with individual differences in children's social judgements about these typically stereotyped groups. Theory of mind, memory, and cognitive inhibition were…

  15. Peer Social Skills and Theory of Mind in Children with Autism, Deafness, or Typical Development

    Science.gov (United States)

    Peterson, Candida; Slaughter, Virginia; Moore, Chris; Wellman, Henry M.

    2016-01-01

    Consequences of theory of mind (ToM) development for daily social lives of children are uncertain. Five to 13-year-olds (N = 195) with typical development, autism, or deafness (both native and late signers) took ToM tests and their teachers reported on their social skills for peer interaction (e.g., leadership, group entry). Groups differed in…

  16. Anxiety, Depression, and Irritability in Children with Autism Relative to Other Neuropsychiatric Disorders and Typical Development

    Science.gov (United States)

    Mayes, Susan Dickerson; Calhoun, Susan L.; Murray, Michael J.; Ahuja, Meesha; Smith, Laura A.

    2011-01-01

    Maternal ratings of anxiety, depression, and irritability were analyzed in 1390 children (6-16 years of age), including 233 children with high functioning autism (HFA, IQ greater than or equal to 80), 117 children with low functioning autism (LFA, IQ less than 80), 187 typical children, and 853 children with other disorders. As a group, children…

  17. Adolescent alcohol exposure and persistence of adolescent-typical phenotypes into adulthood: a mini-review

    Science.gov (United States)

    Spear, Linda Patia; Swartzwelder, H. Scott

    2014-01-01

    Alcohol use is typically initiated during adolescence, which, along with young adulthood, is a vulnerable period for the onset of high-risk drinking and alcohol abuse. Given across-species commonalities in certain fundamental neurobehavioral characteristics of adolescence, studies in laboratory animals such as the rat have proved useful to assess persisting consequences of repeated alcohol exposure. Despite limited research to date, reports of long-lasting effects of adolescent ethanol exposure are emerging, along with certain common themes. One repeated finding is that adolescent exposure to ethanol sometimes results in the persistence of adolescent-typical phenotypes into adulthood. Instances of adolescent -like persistence have been seen in terms of baseline behavioral, cognitive, electrophysiological and neuroanatomical characteristics, along with the retention of adolescent-typical sensitivities to acute ethanol challenge. These effects are generally not observed after comparable ethanol exposure in adulthood. Persistence of adolescent-typical phenotypes is not always evident, and may be related to regionally-specific ethanol influences on the interplay between CNS excitation and inhibition critical for the timing of neuroplasticity. PMID:24813805

  18. Decision-Tree Models of Categorization Response Times, Choice Proportions, and Typicality Judgments

    Science.gov (United States)

    Lafond, Daniel; Lacouture, Yves; Cohen, Andrew L.

    2009-01-01

    The authors present 3 decision-tree models of categorization adapted from T. Trabasso, H. Rollins, and E. Shaughnessy (1971) and use them to provide a quantitative account of categorization response times, choice proportions, and typicality judgments at the individual-participant level. In Experiment 1, the decision-tree models were fit to…

  19. Dietary Patterns and Feeding Problems of Turkish Children with Intellectual Disabilities and Typically Developing Children

    Science.gov (United States)

    Sayin, Kubra; Ilik, Senay

    2017-01-01

    This study aimed to determine whether dietary patterns and feeding problems differ among children with intellectual disabilities (ID) and typically developing children (TDC) in Turkey. This cross-sectional study was conducted in 220 (112 children with ID and 108 TDC) 7-12 aged children in Konya, Turkey. We assessed usual dietary intakes by a…

  20. Magnetic Resonance Spectroscopy of the Thalamus in Patients with Typical Absence Epilepsy

    Czech Academy of Sciences Publication Activity Database

    Fojtíková, D.; Brázdil, M.; Horký, Jaroslav; Mikl, M.; Kuba, R.; Krupa, P.; Rektor, I.

    2006-01-01

    Roč. 7, 2/Suppl. B (2006), B30 ISSN 1335-9592. [International Danube Symposium for Neurological Sciences and Continuing Education /38./. 06.04.2006-08.04.2006, Brno] Institutional research plan: CEZ:AV0Z20650511 Keywords : typical absence epilepsy * idiopathic generalized epilepsy * proton magnetic resonance spectroscopy * thalamus Subject RIV: FS - Medical Facilities ; Equipment

  1. Maternal and paternal pragmatic speech directed to young children with Down syndrome and typical development.

    Science.gov (United States)

    de Falco, Simona; Venuti, Paola; Esposito, Gianluca; Bornstein, Marc H

    2011-02-01

    The aim of this study was to compare functional features of maternal and paternal speech directed to children with Down syndrome and developmental age-matched typically developing children. Altogether 88 parents (44 mothers and 44 fathers) and their 44 young children (22 children with Down syndrome and 22 typically developing children) participated. Parents' speech directed to children was obtained through observation of naturalistic parent-child dyadic interactions. Verbatim transcripts of maternal and paternal language were categorized in terms of the primary function of each speech unit. Parents (both mothers and fathers) of children with Down syndrome used more affect-salient speech compared to parents of typically developing children. Although parents used the same amounts of information-salient speech, parents of children with Down syndrome used more direct statements and asked fewer questions than did parents of typically developing children. Concerning parent gender, in both groups mothers used more language than fathers and specifically more descriptions. These findings held controlling for child age and MLU and family SES. This study highlights strengths and weaknesses of parental communication to children with Down syndrome and helps to identify areas of potential improvement through intervention. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. 16 CFR Figure 5 to Part 1512 - Typical Handbrake Actuator Showing Grip Dimension

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Actuator Showing Grip Dimension EC03OC91.072 ...

  3. Dietary Patterns and Body Mass Index in Children with Autism and Typically Developing Children

    Science.gov (United States)

    Evans, E. Whitney; Must, Aviva; Anderson, Sarah E.; Curtin, Carol; Scampini, Renee; Maslin, Melissa; Bandini, Linda

    2012-01-01

    To determine whether dietary patterns (juice and sweetened non-dairy beverages, fruits, vegetables, fruits and vegetables, snack foods, and kid's meals) and associations between dietary patterns and body mass index (BMI) differed between 53 children with autism spectrum disorders (ASD) and 58 typically developing children, ages 3-11, multivariate…

  4. LAND COVER CHANGE MONITORING OF TYPICAL FUNCTIONAL COMMUNITIES OF SICHUAN PROVINCE BASED ON ZY-3 DATA

    Directory of Open Access Journals (Sweden)

    G. M. Li

    2018-04-01

    Full Text Available According to the function, land space types are divided into key development areas, restricted development areas and forbidden development areas in Sichuan Province. This paper monitors and analyses the changes of land cover in different typical functional areas from 2010 to 2017, which based on ZY-3 high-score images data and combined with statistical yearbook and thematic data of Sichuan Province. The results show that: The land cover types of typical key development zones are mainly composed of cultivated land, forest land, garden land, and housing construction land, which accounts for the total area of land cover 87 %. The land cover types of typical restricted development zone mainly consists of forest land and grassland, which occupy 97.71 % of the total area of the surface coverage. The land cover types of the typical prohibition development zone mainly consist of forest land, grassland, desert and bared earth, which accounts for the total area of land cover 99.31 %.

  5. Training Class Inclusion Responding in Typically Developing Children and Individuals with Autism

    Science.gov (United States)

    Ming, Siri; Mulhern, Teresa; Stewart, Ian; Moran, Laura; Bynum, Kellie

    2018-01-01

    In a "class inclusion" task, a child must respond to stimuli as being involved in two different though hierarchically related categories. This study used a Relational Frame Theory (RFT) paradigm to assess and train this ability in three typically developing preschoolers and three individuals with autism spectrum disorder, all of whom had…

  6. Exercise thallium-201 scintigraphy and prognosis in typical angina pectoris and negative exercise electrocardiography

    International Nuclear Information System (INIS)

    Bairey, C.N.; Rozanski, A.; Maddahi, J.; Resser, K.J.; Berman, D.S.

    1989-01-01

    Patients with a history of typical angina but negative exercise electrocardiography represent a subgroup with an intermediate likelihood of having coronary artery disease and future cardiac events. A retrospective study of the prognostic utility of stress-redistribution thallium-201 scintigraphy was performed in 190 such patients. A second group of 203 patients with typical angina and a positive exercise electrocardiogram were analyzed for comparative scintigraphic purposes. The cardiac event rate for the 144 negative exercise electrocardiogram patients with normal thallium results was 5 vs 15% in the 46 patients with abnormal thallium results (p = 0.01). These patients were further stratified into high (14 to 18%), intermediate (9%) and low (less than 2%) risk groups for future cardiac events based on combining the thallium results with the percentage of maximal predicted heart rate achieved. A multivariate analysis revealed that an abnormal thallium result was the only significant correlate of future cardiac events. Mechanisms responsible for the discordant finding of a negative exercise electrocardiogram in patients with typical angina include (1) false-positive angina symptomatology in low prevalence coronary artery disease groups in whom the thallium test is negative, and (2) electrocardiographically silent ischemia in patients in whom the thallium test is positive. These findings reveal that thallium stress-redistribution scintigraphy can be used to stratify 1-year prognosis in this subgroup of patients with typical angina and negative exercise electrocardiograms

  7. Characterization of typical chemical background interferences in atmospheric pressure ionization liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Guo, Xinghua; Bruins, Andries P.; Covey, Thomas R.

    2006-01-01

    The structures and origins of typical chemical background noise ions in positive atmospheric pressure ionization liquid chromatography/mass spectrometry (API LC/MS) are investigated and summarized in this study. This was done by classifying chemical background ions using precursor and product ion

  8. The typical steps of radiation processes development. Experience in investigation, designing and application

    International Nuclear Information System (INIS)

    Babkin, I. Yu.

    1983-01-01

    The typical steps of radiation processes development are discussed as: primary laboratory investigations; primary economic evaluation; more exact estimation of situation in industry; comparative analysis; development of a flow sheet; pilot plant; obtaining of initial data for designing of industrial scale plant; prediction of industrial situation; designing of semi-industrial or industrial plant; industrial plant. (U.K.)

  9. The Production of Figurative Language in Typically Developing Children and Williams Syndrome

    Science.gov (United States)

    Naylor, Lauren; Van Herwegen, Jo

    2012-01-01

    The current study investigated the development of figurative language production, including different types of figurative expressions, during a fictional narrative in 20 typically developing (TD) children and 20 children with Williams syndrome (WS) aged 7-18 years old. In contrast to previous studies, developmental trajectories showed that (1) the…

  10. Development of Novel Metaphor and Metonymy Comprehension in Typically Developing Children and Williams Syndrome

    Science.gov (United States)

    Van Herwegen, Jo; Dimitriou, Dagmara; Rundblad, Gabriella

    2013-01-01

    This study investigated the development of novel metaphor and metonymy comprehension in both typically developing (TD) children and individuals with Williams syndrome (WS). Thirty-one TD children between the ages of 3;09 and 17;01 and thirty-four individuals with WS between the ages of 7;01 and 44 years old were administered a newly developed task…

  11. The Development of Metaphorical Language Comprehension in Typical Development and in Williams Syndrome

    Science.gov (United States)

    Thomas, Michael S. C.; Van Duuren, Mike; Purser, Harry R. M.; Mareschal, Denis; Ansari, Daniel; Karmiloff-Smith, Annette

    2010-01-01

    The domain of figurative language comprehension was used to probe the developmental relation between language and cognition in typically developing individuals and individuals with Williams syndrome. Extending the work of Vosniadou and Ortony, the emergence of nonliteral similarity and category knowledge was investigated in 117 typically…

  12. Mealtime Problems in Children with Autism Spectrum Disorder and Their Typically Developing Siblings: A Comparison Study

    Science.gov (United States)

    Nadon, Genevieve; Feldman, Debbie Ehrmann; Dunn, Winnie; Gisel, Erika

    2011-01-01

    Many children with autism spectrum disorders (ASD) have mealtime problems. Diagnosis and the social environment may influence eating behaviours. We examined whether children with ASD have more mealtime problems than their typically developing siblings, and whether age and sex are associated with mealtime problems. Forty-eight families participated…

  13. Brain bases of reading fluency in typical reading and impaired fluency in dyslexia.

    Directory of Open Access Journals (Sweden)

    Joanna A Christodoulou

    Full Text Available Although the neural systems supporting single word reading are well studied, there are limited direct comparisons between typical and dyslexic readers of the neural correlates of reading fluency. Reading fluency deficits are a persistent behavioral marker of dyslexia into adulthood. The current study identified the neural correlates of fluent reading in typical and dyslexic adult readers, using sentences presented in a word-by-word format in which single words were presented sequentially at fixed rates. Sentences were presented at slow, medium, and fast rates, and participants were asked to decide whether each sentence did or did not make sense semantically. As presentation rates increased, participants became less accurate and slower at making judgments, with comprehension accuracy decreasing disproportionately for dyslexic readers. In-scanner performance on the sentence task correlated significantly with standardized clinical measures of both reading fluency and phonological awareness. Both typical readers and readers with dyslexia exhibited widespread, bilateral increases in activation that corresponded to increases in presentation rate. Typical readers exhibited significantly larger gains in activation as a function of faster presentation rates than readers with dyslexia in several areas, including left prefrontal and left superior temporal regions associated with semantic retrieval and semantic and phonological representations. Group differences were more extensive when behavioral differences between conditions were equated across groups. These findings suggest a brain basis for impaired reading fluency in dyslexia, specifically a failure of brain regions involved in semantic retrieval and semantic and phonological representations to become fully engaged for comprehension at rapid reading rates.

  14. Television, Video Game and Social Media Use among Children with ASD and Typically Developing Siblings

    Science.gov (United States)

    Mazurek, Micah O.; Wenstrup, Colleen

    2013-01-01

    This study examined the nature of television, video game, and social media use in children (ages 8-18) with autism spectrum disorders (ASD, n = 202) compared to typically developing siblings (TD, n = 179), and relative to other activities. Parents completed measures assessing children's screen-based and other extracurricular activities. Children…

  15. Development of Pointing Gestures in Children with Typical and Delayed Language Acquisition

    Science.gov (United States)

    Lüke, Carina; Ritterfeld, Ute; Grimminger, Angela; Liszkowski, Ulf; Rohlfing, Katharina J.

    2017-01-01

    Purpose: This longitudinal study compared the development of hand and index-finger pointing in children with typical language development (TD) and children with language delay (LD). First, we examined whether the number and the form of pointing gestures during the second year of life are potential indicators of later LD. Second, we analyzed the…

  16. Effects of Semantic Elaboration and Typicality on Picture Naming in Alzheimer Disease

    Science.gov (United States)

    Morelli, Claudia A.; Altmann, Lori J. P.; Kendall, Diane; Fischler, Ira; Heilman, Kennneth M.

    2011-01-01

    Purpose: Individuals with probable Alzheimer disease (pAD) are frequently impaired at picture naming. This study examined whether a semantic elaboration task would facilitate naming in pAD, and whether training either semantically typical or atypical stimulus items facilitated generalized improvement in picture naming and category generation…

  17. Textese and use of texting by children with typical language development and Specific Language Impairment

    NARCIS (Netherlands)

    Blom, W.B.T.; van Dijk, Chantal; Vasic, Nada; van Witteloostuijn, Merel; Avrutin, S.

    2017-01-01

    The purpose of this study was to investigate texting and textese, which is the special register used for sending brief text messages, across children with typical development (TD) and children with Specific Language Impairment (SLI). Using elicitation techniques, texting and spoken language messages

  18. Comparison of Sedentary Behaviors between Children with Autism Spectrum Disorders and Typically Developing Children

    Science.gov (United States)

    Must, Aviva; Phillips, Sarah M.; Curtin, Carol; Anderson, Sarah E.; Maslin, Melissa; Lividini, Keith; Bandini, Linda G.

    2014-01-01

    Time spent in sedentary behavior is largely due to time spent engaged with electronic screen media. Little is known about the extent to which sedentary behaviors for children with autism spectrum disorder differ from typically developing children. We used parental report to assess and compare time spent in sedentary behaviors for 53 children with…

  19. Association between Blood Omega-3 Index and Cognition in Typically Developing Dutch Adolescents

    NARCIS (Netherlands)

    Van der Wurff, Inge; Von Schacke, Clemens; Berge, Kjetil; Zeegers, Maurice; Kirschner, Paul A.; De Groot, Renate

    2017-01-01

    The impact of omega-3 long-chain polyunsaturated fatty acids (LCPUFAs) on cognition is heavily debated. In the current study, the possible association between omega-3 LCPUFAs in blood and cognitive performance of 266 typically developing adolescents aged 13–15 years is investigated. Baseline data

  20. Sample diversity and premise typicality in inductive reasoning: evidence for developmental change.

    Science.gov (United States)

    Rhodes, Marjorie; Brickman, Daniel; Gelman, Susan A

    2008-08-01

    Evaluating whether a limited sample of evidence provides a good basis for induction is a critical cognitive task. We hypothesized that whereas adults evaluate the inductive strength of samples containing multiple pieces of evidence by attending to the relations among the exemplars (e.g., sample diversity), six-year-olds would attend to the degree to which each individual exemplar in a sample independently appears informative (e.g., premise typicality). To test these hypotheses, participants were asked to select between diverse and non-diverse samples to help them learn about basic-level animal categories. Across various between-subject conditions (N=133), we varied the typicality present in the diverse and non-diverse samples. We found that adults reliably selected to examine diverse over non-diverse samples, regardless of exemplar typicality, six-year-olds preferred to examine samples containing typical exemplars, regardless of sample diversity, and nine-year-olds were somewhat in the midst of this developmental transition.