WorldWideScience

Sample records for high adsorption ability

  1. Adsorption ability of the carbon black for nickel ions uptake from aqueous solution

    OpenAIRE

    Rađenović Ankica; Malina Jadranka

    2013-01-01

    Surface modification can be performed by adsorption of certain organic compounds on the surface of carbon. The main objective of this work was to compare the adsorption ability of acid-modified carbon black with the non-modified one. Modification process was performed by adsorption of acetic acid onto commercial carbon black surface. A batch adsorption system was applied to study the both adsorption reaction, acetic acid and Ni(II) adsorption onto the carbon black. Adsorption isotherms ...

  2. Adsorption

    Directory of Open Access Journals (Sweden)

    Denis J.L. Guerra

    2016-09-01

    Full Text Available Nontronite is an important phyllosilicate with a high concentration of ferric iron in the octahedral layer. A new occurrence of Brazilian nontronite sample was used for the organofunctionalization process with 3-aminopropyltriethoxysilane. Due to the increment of basic centers attached to the pendant chains, the metal adsorption capability of the final chelating material, was found to be higher than its precursor. The ability of these materials to remove Pb2+, Mn2+, and Zn2+ from aqueous solutions was followed by a series of adsorption isotherms at room temperature and pH 6.0, in batch adsorption experiments in order to explain the adsorption mechanism. In order to evaluate the phyllosilicate samples as adsorbents in a dynamic system, a glass column was fulfilled with nontronite samples (1.5 g and it was fed with 2.1 mmol dm−3 divalent cations at pH 6.0. The energetic effects caused by metal cations adsorption were determined through calorimetric titrations. The effects of three divalent metals adsorption in the zero point of charge of each material were investigated.

  3. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-04-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.

  4. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-01-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion. PMID:28367985

  5. High Pressure Multicomponent Adsorption in Porous Media

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1999-01-01

    We analyse adsorption of a multicomponent mixture at high pressure on the basis of the potential theory of adsorption. The adsorbate is considered as a segregated mixture in the external field produced by a solid adsorbent. we derive an analytical equation for the thickness of a multicomponent film...... close to a dew point. This equation (asymptotic adsorption equation, AAE) is a first order approximation with regard to the distance from a phase envelope....

  6. High ability: Giftedness and talent

    Directory of Open Access Journals (Sweden)

    María Dolores Prieto Sánchez

    2010-04-01

    Full Text Available This special issue of the journal aims at putting together national and international research on high abilities, and is divided into three sections: 1 Roles and cognitive, emotional and professional competences of high ability students’ teachers, 2 Identification and assessment of high ability students, 3 Analysis of practices, programs and mentoring of high ability students’ attention to diversity.The articles are authored by scholars from nine different countries (Spain, Argentina, UK, USA, Russia, Brazil, Saudi Arabia, Portugal and Poland, from sixteen different Spanish and international universities: Alicante (Spain, Autónoma de Barcelona (Spain, Málaga (Spain, Murcia (Spain, Navarra (Spain, Oviedo (Spain, Tufts University (USA, Yale University (USA, Moscow State University (Russia, Nacional de La Plata (Argentina, University of Connecticut (USA, Universidade do Minho (Portugal, Universidade da Beira Interior (Portugal, Universidade do Estado do Rio de Janeiro (Brazil, King Faisal University (Saudi Arabia and Universidad de Szczecin (Poland.

  7. Adsorption ability of the carbon black for nickel ions uptake from aqueous solution

    Directory of Open Access Journals (Sweden)

    Rađenović Ankica

    2013-01-01

    Full Text Available Surface modification can be performed by adsorption of certain organic compounds on the surface of carbon. The main objective of this work was to compare the adsorption ability of acid-modified carbon black with the non-modified one. Modification process was performed by adsorption of acetic acid onto commercial carbon black surface. A batch adsorption system was applied to study the both adsorption reaction, acetic acid and Ni(II adsorption onto the carbon black. Adsorption isotherms of acetic acid and Ni(II adsorption onto the non-modified and modified carbon black were fitted by classical adsorption models, such as Freundlich and Langmuir models. Modified carbon black surface become more active for Ni(II ions removal from aqueous solutions. The results showed that modification by acetic acid increases the adsorption capacity of carbon black from 18.3823 mg Ni(II g-1 to 86.9566 mg Ni(II g-1. SEM analysis enabled the observation of any surface changes in the carbon black that have occurred due to either acid modification or Ni(II adsorption.

  8. Challenging high-ability students

    NARCIS (Netherlands)

    Scager, Karin; Akkerman, Sanne F.; Pilot, Albert; Wubbels, Theo; Hafd Onderwijsadvies en training; Leerstoel Vermunt; Faculteit Sociale Wetenschappen; LS Wubbels; Education and Learning: Development in Interaction

    2014-01-01

    The existing literature on indicators of an optimal learning environment for high-ability students frequently discusses the concept of challenge. It is, however, not clear what, precisely, constitutes appropriate challenge for these students. In this study, the authors examined an undergraduate hono

  9. Challenging High-Ability Students

    Science.gov (United States)

    Scager, Karin; Akkerman, Sanne F.; Pilot, Albert; Wubbels, Theo

    2014-01-01

    The existing literature on indicators of an optimal learning environment for high-ability students frequently discusses the concept of challenge. It is, however, not clear what, precisely, constitutes appropriate challenge for these students. In this study, the authors examined an undergraduate honours course, Advanced Cell Biology, which has…

  10. Challenging high-ability students

    NARCIS (Netherlands)

    Scager, Karin; Akkerman, Sanne F.; Pilot, Albert; Wubbels, Theo; Hafd Onderwijsadvies en training; Leerstoel Vermunt; Faculteit Sociale Wetenschappen; LS Wubbels; Education and Learning: Development in Interaction

    2014-01-01

    The existing literature on indicators of an optimal learning environment for high-ability students frequently discusses the concept of challenge. It is, however, not clear what, precisely, constitutes appropriate challenge for these students. In this study, the authors examined an undergraduate hono

  11. Preparation of hollow core/shell microspheres of hematite and its adsorption ability for samarium.

    Science.gov (United States)

    Yu, Sheng-Hui; Yao, Qi-Zhi; Zhou, Gen-Tao; Fu, Sheng-Quan

    2014-07-01

    Hollow core/shell hematite microspheres with diameter of ca. 1-2 μm have been successfully achieved by calcining the precursor composite microspheres of pyrite and polyvinylpyrrolidone (PVP) in air. The synthesized products were characterized by a wide range of techniques including powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and Brunauer-Emmett-Teller (BET) gas sorptometry. Temperature- and time-dependent experiments unveil that the precursor pyrite-PVP composite microspheres finally transform into hollow core/shell hematite microspheres in air through a multistep process including the oxidation and sulfation of pyrite, combustion of PVP occluded in the precursor, desulfation, aggregation, and fusion of nanosized hematite as well as mass transportation from the interior to the exterior of the microspheres. The formation of the hollow core/shell microspheres dominantly depends on the calcination temperature under current experimental conditions, and the aggregation of hematite nanocrystals and the core shrinking during the oxidation of pyrite are responsible for the formation of the hollow structures. Moreover, the adsorption ability of the hematite for Sm(III) was also tested. The results exhibit that the hematite microspheres have good adsorption activity for trivalent samarium, and that its adsorption capacity strongly depends on the pH of the solution, and the maximum adsorption capacity for Sm(III) is 14.48 mg/g at neutral pH. As samarium is a typical member of the lanthanide series, our results suggest that the hollow hematite microspheres have potential application in removal of rare earth elements (REEs) entering the water environment.

  12. Teachers of high ability pupils

    Directory of Open Access Journals (Sweden)

    Cándido Genovard

    2010-04-01

    Full Text Available In this article we analyze the characteristics of gifted and talented students’ expert teachers. The subject background and the specific proprieties of the instructional process to meet gifted students’ educational needs are analyzed. The value of teacher-student interactions and of teaching and learning styles are highlighted. Also, we include different action guidelines and instructional resources to use in the classroom to teach these students. There is not an ideal teacher for high ability students. However, teachers must know what the teaching-learning processes are and how these work, and the diverse psychological, content and contextual variables involved in such processes.

  13. Adsorption ability of rare earth elements on clay minerals and its practical performance

    Institute of Scientific and Technical Information of China (English)

    肖燕飞; 龙志奇; 黄莉; 冯宗玉; 王良士

    2016-01-01

    The adsorption behaviors of rare earth elements on clay minerals would have great influence on the mineralization process and the leaching process of the ion-adsorption type rare earths ore. In this work, the adsorption thermodynamics of REEs on kaolin were investigated thoroughly and systematically. The experimental results showed that the adsorption characteristics of La, Nd, Y on kaolin did fit well with the Langmuir isotherm model and their saturated adsorption capacities were 1.731, 1.587 and 0.971 mg/g, re-spectively. The free energy change (ΔG) values were –16.91 kJ/mol (La), –16.05 kJ/mol (Nd) and –15.58 kJ/mol (Y), respectively. The negative values ofΔG demonstrated that the adsorption of rare earth on kaolin was a spontaneously physisorption process. The deposit characteristic of the volcanic ion-adsorption type rare earths ore and the behavior of the rare earth in the column leaching process were also developed here. With the increase of the ore body depth, the distribution of the LREEs decreased and the HREEs increased. And the slight differences in the adsorption ability of REEs on clay minerals led to the fractionation effect in the column leaching process. These developed more evidences and better understanding of metallogenic regularity, and provided a theoretical ba-sis and scientific approach to separation of the HREEs and LREEs in the leaching process.

  14. Preparation, Characterization and Methylene Blue Dye Adsorption Ability of Acid Activated-Natural Zeolite

    Science.gov (United States)

    Saputra, O. A.; Prameswari, M. D.; Kinanti, V. T. D.; Mayasari, O. D.; Sutarni, Y. D.; Apriany, K.; Lestari, W. W.

    2017-02-01

    The aim of this research was to prepare an acid-activated natural zeolite (Ac-Zeo) as a low-cost adsorbent material and to investigate their ability on methylene blue dye removal in aqueous solution. The natural zeolite was activated using hydrochloric acid and the final product was characterized using Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The adsorption process was carried out using the batch method. Some parameters like pH condition, contact time and varied dye initial concentration were studied to determine the adsorption ability of Ac-Zeo. In this study, kinetic adsorption was evaluated using pseudo-second order model approach and found that the kinetic adsorption rate constanta (k) and adsorption capacity at equilibrium are 0.1872 mg.g-1.min-1 and 14.94 mg.g-1, respectively. Moreover, Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich isotherm adsorption models as well as sorption mechanism were studied in this research.

  15. Compact High Efficiency Adsorption Heat Pump

    OpenAIRE

    TeGrotenhuis, Ward E; Humble, Paul H; Sweeney, Josh B

    2012-01-01

    An innovative adsorption cycle heat pump technology is presented that is compact and capable of achieving high energy efficiency for integrated space heating, air conditioning, and water heating. High energy efficiency is accomplished by effectively recuperating heat within the system to minimize energy consumption. This substantially reduces the thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. Furthermore, equipment cost is reduc...

  16. Determination of absolute adsorption in highly ordered porous media

    Science.gov (United States)

    Mertens, Florian O.

    2009-06-01

    Recently developed Metal Organic Frameworks (MOFs) are the materials with the highest intrinsic surface areas to date and their discovery increased the research activity in the field of microporous adsorption materials significantly. In this contribution, a generic method of analysis for volumetrically measured adsorption isotherms is presented that separates absolute adsorption from excess adsorption to the best possible degree by representing the absolute adsorption isotherm by a superposition of in respect to pressure strictly monotonously increasing fitting function. The procedure allows to determine the heat of adsorption at constant gas uptake via implicitly defined quantities. The method was applied to adsorption data of hydrogen on MOF-5 ranging from 40 K to 200 K. Methane adsorption on MOF-5 was used to demonstrate that the common practice of neglecting the difference between excess and absolute adsorption leads to erroneously increased heat of adsorption values at high coverages and temperatures.

  17. Explaining High Abilities of Nobel Laureates

    Science.gov (United States)

    Shavinina, Larisa

    2004-01-01

    Although the Nobel Prize is associated with a rare, superior degree of intellectually creative achievement, high abilities of Nobel laureates are far from well explained. This paper argues that Nobel laureates' high abilities are determined in part by their extracognitive abilities, that is, specific feelings, preferences, beliefs and intuitive…

  18. High Ability Students' Voice on Learning Motivation

    Science.gov (United States)

    Garn, Alex C.; Jolly, Jennifer L.

    2014-01-01

    This study used a self-determination theory lens to investigate high ability learners' motivational experiences. Participants were 15 high ability youth involved in a summer learning camp for gifted students. Two major themes emerged from qualitative data analysis: (a) "The Fun Factor of Learning" and (b) "The Rewards and Pressures…

  19. Purpose in Life among High Ability Adolescents

    Science.gov (United States)

    Bronk, Kendall Cotton; Finch, W. Holmes; Talib, Tasneem L.

    2010-01-01

    Leading high ability scholars have proposed theories that suggest a purpose in life may be particularly prevalent among high ability youth; however, the prevalence of purpose has not been empirically assessed among this population. Therefore using in-depth interviews the present study established the prevalence of purpose among a sample of high…

  20. Efficient removal and highly selective adsorption of Hg2+ by polydopamine nanospheres with total recycle capacity

    Science.gov (United States)

    Zhang, Xiulan; Jia, Xin; Zhang, Guoxiang; Hu, Jiamei; Sheng, Wenbo; Ma, Zhiyuan; Lu, Jianjiang; Liu, Zhiyong

    2014-09-01

    This study reported a new method for efficient removal of Hg2+ from contaminated water using highly selective adsorptive polydopamine (PDA) nanospheres, which were uniform and had a small diameter (150-200 nm). The adsorption isotherms, kinetics, thermodynamics were investigated. Also, the effects of ionic strength, co-existing ions on removing ability of PDA nanospheres for Hg2+ were studied. Adsorption of Hg2+ was very fast and efficient as adsorption equilibrium was completed within 4 h and the maximum adsorption capacities were 1861.72 mg/g, 2037.22 mg/g, and 2076.81 mg/g at 298 K, 313 K, and 328 K respectively, increasing with increasing of temperature. The PDA nanospheres exhibited highly selective adsorption of Hg2+ and had a total desorption capacity of 100% in hydrochloric acid solution, pH 1. The results showed that the structure of PDA nanospheres remained almost unchanged after recycling five times. Furthermore, X-ray photoelectron spectroscopy (XPS) was employed to determine the elements of PDA nanospheres before and after Hg2+ adsorption. Considering their efficient and highly Hg2+ selective adsorption, total recycle capacity, and high stability, PDA nanospheres will be feasible in a number of practical applications.

  1. Component analysis and heavy metal adsorption ability of extracellular polymeric substances (EPS) from sulfate reducing bacteria.

    Science.gov (United States)

    Yue, Zheng-Bo; Li, Qing; Li, Chuan-chuan; Chen, Tian-hu; Wang, Jin

    2015-10-01

    Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS. Potentiometric titration results indicated that the acidic constants (pKa) of the EPS fell into three ranges of 3.5-4.0, 5.9-6.7, and 8.9-9.8. The adsorption site concentrations of the surface functional groups also increased. Adsorption results suggested that EPS had a specific binding affinity for the dosed heavy metal, and that EPS extracted from the Zn(2+)-dosed system had a higher binding affinity for all heavy metals. Additionally, Zn(2+) decreased the inhibitory effects of Cd(2+) and Cu(2+) on the SRB.

  2. Thermal Treatment of Cerium Oxide and Its Properties: Adsorption Ability versus Degradation Efficiency

    Directory of Open Access Journals (Sweden)

    Pavel Janoš

    2014-01-01

    Full Text Available Cerium oxide belongs to the most important heterogeneous catalysts, but its applicability as so-called reactive sorbent for the degradation of toxic chemicals was only recently discovered. For these purposes, cerium oxide is prepared by precipitation of insoluble cerium salts (carbonates with a subsequent thermal decomposition. Properties of cerium oxide prepared from the carbonate precursor are strongly affected by the temperature during the calcination. Main physicochemical properties of cerium oxide (specific surface area, crystallinity, and surface chemistry were examined in dependence on the calcination temperature. As the adsorptive properties of CeO2 are undoubtedly of great importance in the abovementioned applications, the adsorption ability was studied using an azo dye Acid Orange 7 (AO7 as a model compound. The highest sorption efficiency towards AO7 exhibited sorbents prepared at temperatures below 700°C, which was attributed mainly to the presence of hydroxyl groups on the oxide surface. A strong correlation was found between an adsorption efficiency of cerium oxides and their degradation efficiency for organophosphate pesticide parathion methyl. The >Ce–OH groups on the sorbent surface are responsible for the dye binding by the surface-complexation mechanism, and probably also for the nucleophilic cleavage of the P–O–aryl bond in the pesticide molecule.

  3. Generalist genes and high cognitive abilities.

    Science.gov (United States)

    Haworth, Claire M A; Dale, Philip S; Plomin, Robert

    2009-07-01

    The concept of generalist genes operating across diverse domains of cognitive abilities is now widely accepted. Much less is known about the etiology of the high extreme of performance. Is there more specialization at the high extreme? Using a representative sample of 4,000 12-year-old twin pairs from the UK Twins Early Development Study, we investigated the genetic and environmental overlap between web-based tests of general cognitive ability, reading, mathematics and language performance for the top 15% of the distribution using DF extremes analysis. Generalist genes are just as evident at the high extremes of performance as they are for the entire distribution of abilities and for cognitive disabilities. However, a smaller proportion of the phenotypic intercorrelations appears to be explained by genetic influences for high abilities.

  4. THERMODYNAMIC STUDY OF HIGH-PRESSURE ADSORPTION OF METHANE AND HEATS OF METHANE ADSORPTION ON MICROPOROUS CARBONS

    Institute of Scientific and Technical Information of China (English)

    杨晓东; 林文胜; 郑青榕; 顾安忠; 鲁雪生; 宋燕

    2002-01-01

    The study was done for high-pressure adsorption of methane on microporous carbons, which has an ANG vehicular application background. Adsorption isotherm of methane on super activated carbon up to 6 MPa was measured and isosteric heats of methane adsorption on a number of microporous carbons were determined from adsorption isosteres by the Clausius-Clapeyron equation. The variation of the isosteric heats of adsorption with the amount of methane adsorbed was discussed.

  5. Creativity, synthetic intelligence and high ability

    Directory of Open Access Journals (Sweden)

    Marta Sainz

    2010-04-01

    Full Text Available The objective of this study is to analyze the construct of creativity and its relationship with high ability, presenting different definitions, assessment tools and strategies to encourage their development in the school context. The paper is structured into five sections: firstly, we define the concept of creativity. Secondly, we present the most relevant instruments used in the analysis of high ability students’ creativity. Thirdly, we look into several studies on creativity and high abilitiy, highlighting the main limitations of the research carried out. Fourthly, we present principles and strategies in order to foster creativity in the school context. Finally, some conclusions are drawn on the relationship between creativity and high ability.

  6. Porous anionic indium-organic framework with enhanced gas and vapor adsorption and separation ability.

    Science.gov (United States)

    Huang, Yuanbiao; Lin, Zujin; Fu, Hongru; Wang, Fei; Shen, Min; Wang, Xusheng; Cao, Rong

    2014-09-01

    A three-dimensional microporous anionic metal-organic framework (MOF) (Et4N)3[In3(TATB)4] (FJI-C1, H3TATB=4,4',4''-s-triazine-2,4,6-triyltribenzoic acid) with large unit cell volume has been synthesized. Assisted by the organic cation group Et4N in the pores of the compound, FJI-C1 not only shows high adsorption uptakes of C2 and C3 hydrocarbons, but also exhibits highly selective separation of propane, acetylene, ethane, and ethylene from methane at room temperature. Furthermore, it also exhibits high separation selectivity for propane over C2 hydrocarbons and acetylene can be readily separated from their C2 hydrocarbons mixtures at low pressure due to the high selectivity for C2H2 in comparison to C2H4 and C2H6. In addition, FJI-C1 with hydrophilic internal pores surfaces shows highly efficient adsorption separation of polar molecules from nonpolar molecules. Notably, it exhibits high separation selectivity for benzene over cyclohexane due to the π-π interactions between benzene molecules and s-triazine rings of the porous MOF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Adsorption on Highly Ordered Porous Alumina

    Science.gov (United States)

    Mistura, Giampaolo; Bruschi, Lorenzo; Lee, Woo

    2016-10-01

    Porous anodic aluminum oxide (AAO) is characterized by a regular arrangement of the pores with a narrow pore size distribution over extended areas, uniform pore depth, and solid pore walls without micropores. Thanks to significant improvements in anodization techniques, structural engineering of AAO allows to accurately tailor the pore morphology. These features make porous AAO an excellent substrate to study adsorption phenomena. In this paper, we review recent experiments involving the adsorption in porous AAO. Particular attention will be devoted to adsorption in straight and structured pores with a closed end which shed new light on fundamental issues like the origin of hysteresis in closed end pores and the nature of evaporation from ink-bottle pores. The results will be compared to those obtained in other synthetic materials like porous silicon and silica.

  8. Do High Ability Students Have Mathematics Anxiety?

    Science.gov (United States)

    Yeo, Kai Kow Joseph

    2004-01-01

    This exploratory study investigates the level of mathematics anxiety among 116 high ability Secondary Two students. These students were from the top 10% of the Secondary Two students in Singapore. Mathematics Anxiety was measured using the Fennema-Sherman Mathematics Anxiety Scale (MAS) (Fennema & Sherman, 1978) which consisted of twelve items…

  9. Extracurricular enrichment workshops for high ability students

    Directory of Open Access Journals (Sweden)

    Ángela Rojo

    2010-04-01

    Full Text Available The aim of this article is to analyze and explain attention to diversity measures for high ability (gifted and talented students. The model, developed in the Spanish region of Murcia, is based on cognitive psychology and aims to encourage thinking skills. The program is developed as a curriculum extension and the interests, motivations and abilities of children have been considered once these were identified. The article offers a theoretical approach, a set of objectives, and some of the activities that have been done with students.

  10. Highly efficient adsorption of chlorophenols onto chemically modified chitosan

    Science.gov (United States)

    Zhou, Liang-Chun; Meng, Xiang-Guang; Fu, Jing-Wei; Yang, Yu-Chong; Yang, Peng; Mi, Chun

    2014-02-01

    A novel chemically modified chitosan CS-SA-CD with phenol and β-cyclodextrin groups was prepared. The adsorptions of phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) on the functional chitosan from aqueous solution were investigated. CS-SA-CD exhibited excellent adsorption ability for chlorophenols especially for DCP and TCP. The maximum adsorption capacities of phenol, 2-CP, 4-CP, DCP and TCP on CS-SA-CD were 59.74, 70.52, 96.43, 315.46 and 375.94 mg/g, respectively. The scanning electron microscope and Brunauer-Emmett-Teller analyses revealed that the introduction of phenol group changed the surface morphology and surface properties of chitosan. The modified chitosan CS-SA-CD possesses larger surface areas (4.72 m2/g), pore volume (7.29 × 10-3 mL/g) and average pore diameter (59.99 Å) as compared to those of chitosan 3.27 m2/g, 2.00 × 10-3 mL/g and 15.95 Å, respectively. The enhanced adsorption of chlorophenols was also attributed to the interaction of hydrogen bond between Cl atom and sbnd OH group. The adsorption of chlorophenols on CS-SA-CD followed the pseudo-second-order kinetic model. Adsorbent could be regenerated easily and the regenerated CS-SA-CD remained 80-91% adsorption efficiency.

  11. Adsorptive

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Gupta

    2017-05-01

    Full Text Available This work explores the feasibility of natural fibers derived from Ficus carica plant as an alternative precursor for the preparation of activated carbon via microwave assisted H3PO4 activation. The properties of activated carbon were investigated by scanning electron microscope (SEM and Fourier transform spectroscopy (FTIR. The operational parameters, chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were investigated. Adsorption performance of Cu(II and Ni(II onto activated carbon was investigated as a function of pH, contact time, initial metal ion concentration and temperature. The adsorption capacity of Cu(II and Ni(II onto the adsorbent was found to be 23.08 and 18.78 mg/g, respectively. Adsorption of metal ions followed second order kinetics with best fit for Fraundlich adsorption isotherm. The values of thermodynamic parameters such as enthalpy change (ΔH°, entropy change (ΔS° and free energy change (ΔG° were evaluated for the adsorption of both the metal ions. Adsorption of metal ions onto activated carbon was spontaneous and endothermic in nature. The results suggested that activated carbon developed from natural fibers successfully improved the metal ions adsorption capacity. On the basis of our findings, the adsorbent could be used as a detoxifying agent for better management of industrial effluents.

  12. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins.

    Science.gov (United States)

    Kato, Katsuya; Nakamura, Hitomi; Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol-gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO)20(PO)70(EO)20) or F127 ((EO)106(PO)70(EO)106), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A-IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors.

  13. Modeling high-pressure adsorption of gas mixtures on activated carbon and coal using a simplified local-density model.

    Science.gov (United States)

    Fitzgerald, James E; Robinson, Robert L; Gasem, Khaled A M

    2006-11-07

    The simplified local-density (SLD) theory was investigated regarding its ability to provide accurate representations and predictions of high-pressure supercritical adsorption isotherms encountered in coalbed methane (CBM) recovery and CO2 sequestration. Attention was focused on the ability of the SLD theory to predict mixed-gas adsorption solely on the basis of information from pure gas isotherms using a modified Peng-Robinson (PR) equation of state (EOS). An extensive set of high-pressure adsorption measurements was used in this evaluation. These measurements included pure and binary mixture adsorption measurements for several gas compositions up to 14 MPa for Calgon F-400 activated carbon and three water-moistened coals. Also included were ternary measurements for the activated carbon and one coal. For the adsorption of methane, nitrogen, and CO2 on dry activated carbon, the SLD-PR can predict the component mixture adsorption within about 2.2 times the experimental uncertainty on average solely on the basis of pure-component adsorption isotherms. For the adsorption of methane, nitrogen, and CO2 on two of the three wet coals, the SLD-PR model can predict the component adsorption within the experimental uncertainties on average for all feed fractions (nominally molar compositions of 20/80, 40/60, 60/40, and 80/20) of the three binary gas mixture combinations, although predictions for some specific feed fractions are outside of their experimental uncertainties.

  14. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Katsuya, E-mail: katsuya-kato@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Nakamura, Hitomi [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro [Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan)

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol–gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO){sub 20}(PO){sub 70}(EO){sub 20}) or F127 ((EO){sub 106}(PO){sub 70}(EO){sub 106}), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A–IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors. - Highlights: • VUV-treated MPS thin films with removed polymer had uniform pore. • VUV-treated MPS thin films exhibited high sensitivity by ELISA. • Cytochrome c showed the catalytic activity and recyclability on synthesized films.

  15. Highly efficient adsorption of chlorophenols onto chemically modified chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liang-Chun [Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (China); National Center for Packaging Material Quality Supervision and Inspection, Chengdu Institute of Product Quality Supervision and Inspection, Chengdu 610064 (China); Meng, Xiang-Guang, E-mail: mengxgchem@163.com [Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (China); Fu, Jing-Wei [National Center for Packaging Material Quality Supervision and Inspection, Chengdu Institute of Product Quality Supervision and Inspection, Chengdu 610064 (China); Yang, Yu-Chong; Yang, Peng; Mi, Chun [Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (China)

    2014-02-15

    A novel chemically modified chitosan CS-SA-CD with phenol and β-cyclodextrin groups was prepared. The adsorptions of phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) on the functional chitosan from aqueous solution were investigated. CS-SA-CD exhibited excellent adsorption ability for chlorophenols especially for DCP and TCP. The maximum adsorption capacities of phenol, 2-CP, 4-CP, DCP and TCP on CS-SA-CD were 59.74, 70.52, 96.43, 315.46 and 375.94 mg/g, respectively. The scanning electron microscope and Brunauer–Emmett–Teller analyses revealed that the introduction of phenol group changed the surface morphology and surface properties of chitosan. The modified chitosan CS-SA-CD possesses larger surface areas (4.72 m{sup 2}/g), pore volume (7.29 × 10{sup −3} mL/g) and average pore diameter (59.99 Å) as compared to those of chitosan 3.27 m{sup 2}/g, 2.00 × 10{sup −3} mL/g and 15.95 Å, respectively. The enhanced adsorption of chlorophenols was also attributed to the interaction of hydrogen bond between Cl atom and -OH group. The adsorption of chlorophenols on CS-SA-CD followed the pseudo-second-order kinetic model. Adsorbent could be regenerated easily and the regenerated CS-SA-CD remained 80–91% adsorption efficiency.

  16. Adsorption

    Directory of Open Access Journals (Sweden)

    Sushmita Banerjee

    2017-05-01

    Full Text Available Application of saw dust for the removal of an anionic dye, tartrazine, from aqueous solutions has been investigated. The experiments were carried out in batch mode. Effect of the parameters such as pH, initial dye concentration and temperature on the removal of the dye was studied. Equilibrium was achieved in 70 min. Maximum adsorption of dye was achieved at pH 3. Removal percent was found to be dependent on the initial concentration of dye solution, and maximum removal was found to be 97% at 1 mg/L of tartrazine. The removal increases from 71% to 97% when the initial concentration of dye solution decreases from 15 mg/L to 1 mg/L. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. The (Langmuir adsorption capacity of the adsorbent is found to be 4.71 mg/g at 318 K. Kinetic modeling of the process of removal was carried out and the process of removal was found to follow a pseudo second order model and the value of rate constant for adsorption process was calculated as 2.7 × 10−3 g mg−1 min−1 at 318 K. The thermodynamic parameters such as change in free energy (ΔG°, enthalpy (ΔH° and entropy (ΔS° were determined and the negative values of ΔG° indicated that the process of removal was spontaneous at all values of temperatures. Further, the values of ΔH° indicated the endothermic nature of the process of removal.

  17. Preparation and Adsorption Ability of Polysulfone Microcapsules Containing Modified Chitosan Gel

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; LUO Guangsheng; YANG Weiwei; WANG Yujun

    2005-01-01

    Chemically modified chitosan beads containing polyethyleneimine (PEI) were prepared to improve the metal ion adsorption capacity of the chitosan beads and their mechanical stability and to limit their biodegradability. The modified beads were encapsulated with the polymer material polysulfone by a novel surface coating method named the emulsion phase inversion method. The adsorption properties of the modified beads and the microstructures of the polysulfone coating layer were then analyzed. The experimental results showed that the PEI was successfully linked onto the chitosan beads. The density of the -NH2 groups in the modified beads was significantly increased, while the water content was reduced. The coating layer thickness was about 200 (m. The modified chitosan gel beads had excellent Cu(II) adsorption capacity, with a maximum Cu(II) adsorption capacity 1.34 times higher than that of the unmodified beads. The results show that even with the polysulfone coating the adsorption kinetics of the modified beads is still better than those of the unmodified beads. The modifications improve the mass transfer performance of the chitosan beads as well as the bead stability.

  18. Graphene oxide foams and their excellent adsorption ability for acetone gas

    Energy Technology Data Exchange (ETDEWEB)

    He, Yongqiang [Department of Applied Chemistry, Yuncheng University, Yuncheng 044000 (China); School of Science, Tianjin University, Tianjin 300072 (China); Zhang, Nana; Wu, Fei; Xu, Fangqiang; Liu, Yu [School of Science, Tianjin University, Tianjin 300072 (China); Gao, Jianping, E-mail: jianpingg@eyou.com [School of Science, Tianjin University, Tianjin 300072 (China)

    2013-09-01

    Graphical abstract: - Highlights: • GO and RGO foams were prepared using a simple and green method, unidirectional freeze-drying. • The porous structure of the foams can be adjusted by changing GO concentrations. • GO and RGO foams show good adsorption efficiency for acetone gas. - Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) foams were prepared using a unidirectional freeze-drying method. These porous carbon materials were characterized by thermal gravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and scanning electron microscopy. The adsorption behavior of the two kinds of foams for acetone was studied. The result showed that the saturated adsorption efficiency of the GO foams was over 100%, and was higher than that of RGO foams and other carbon materials.

  19. High Intellectual Ability: Extracurricular Enrichment and Cognitive Management

    Science.gov (United States)

    Sastre-Riba, Sylvia

    2013-01-01

    This study aims to provide a better understanding of high intellectual abilities and of how to address the educational needs of those who possess such abilities. Within the emergent paradigm, high intellectual abilities are understood as multidimensional and as the result of lifetime development; that is, not only are they the result of their…

  20. Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5.

    Science.gov (United States)

    Ding, Wenjin; Baracchini, Giulia; Klumpp, Michael; Schwieger, Wilhelm; Dittmeyer, Roland

    2016-08-25

    We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 °C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 °C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 °C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 °C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

  1. Efficient removal and highly selective adsorption of Hg{sup 2+} by polydopamine nanospheres with total recycle capacity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiulan [School of Chemistry and Chemical Engineering, Key Laboratory for Green Processing of Chemical Engineering of Xinjiang bingtuan, Shihezi University, Shihezi 832003 (China); Jia, Xin, E-mail: jiaxin@shzu.edu.cn [School of Chemistry and Chemical Engineering, Key Laboratory for Green Processing of Chemical Engineering of Xinjiang bingtuan, Shihezi University, Shihezi 832003 (China); Zhang, Guoxiang [Gansu Dayu Water-saving Group Co., Ltd, Jiuquan 735000 (China); Hu, Jiamei; Sheng, Wenbo; Ma, Zhiyuan; Lu, Jianjiang; Liu, Zhiyong [School of Chemistry and Chemical Engineering, Key Laboratory for Green Processing of Chemical Engineering of Xinjiang bingtuan, Shihezi University, Shihezi 832003 (China)

    2014-09-30

    Highlights: • The PDA nanospheres with uniform diameter of 150–200 nm were used to remove Hg{sup 2+} efficiently and selectively. • The desorption capacity of PDA nanospheres was 100% in pH 1. • The structure and removal capacity of PDA nanospheres remained almost unchanged after recycling five times. - Abstract: This study reported a new method for efficient removal of Hg{sup 2+} from contaminated water using highly selective adsorptive polydopamine (PDA) nanospheres, which were uniform and had a small diameter (150–200 nm). The adsorption isotherms, kinetics, thermodynamics were investigated. Also, the effects of ionic strength, co-existing ions on removing ability of PDA nanospheres for Hg{sup 2+} were studied. Adsorption of Hg{sup 2+} was very fast and efficient as adsorption equilibrium was completed within 4 h and the maximum adsorption capacities were 1861.72 mg/g, 2037.22 mg/g, and 2076.81 mg/g at 298 K, 313 K, and 328 K respectively, increasing with increasing of temperature. The PDA nanospheres exhibited highly selective adsorption of Hg{sup 2+} and had a total desorption capacity of 100% in hydrochloric acid solution, pH 1. The results showed that the structure of PDA nanospheres remained almost unchanged after recycling five times. Furthermore, X-ray photoelectron spectroscopy (XPS) was employed to determine the elements of PDA nanospheres before and after Hg{sup 2+} adsorption. Considering their efficient and highly Hg{sup 2+} selective adsorption, total recycle capacity, and high stability, PDA nanospheres will be feasible in a number of practical applications.

  2. Effects of nano-surface properties on initial osteoblast adhesion and Ca/P adsorption ability for titanium alloys.

    Science.gov (United States)

    Wang, C C; Hsu, Y C; Hsieh, M C; Yang, S P; Su, F C; Lee, T M

    2008-08-20

    Titanium alloys (Ti6Al4V), while subjected to high temperature surface treatment, experience altered nano-surface characteristics. The effects of such surface treatments are examined, including the initial adhesion force experienced by osteoblasts, the Ca/P adsorption capability, and the nano-surface properties, including the amounts of amphoteric Ti-OH groups, surface topography, and surface roughness. The initial adhesion force is considered a quantitative indicator of cyto-compatibility in vitro. Previously, a cyto-detacher was applied in a pioneer attempt measuring the initial adhesion force of fibroblasts on a metal surface. Presently, the cyto-detacher is further applied to evaluate the initial adhesion force of osteoblasts. Results reveal that (1) titanium alloys subjected to heat treatment could promote the adsorption capability of Ca and P; (2) titanium alloys subjected to heat treatment could have higher initial osteoblast adhesion forces; (3) the adhesion strength of osteoblasts, ranging from 38.5 to 58.9 nN (nanonewtons), appears stronger for rougher surfaces. It is concluded that the heat treatment could have impacted the biocompatibility in terms of the initial osteoblast adhesion force and Ca/P adsorption capability.

  3. High gradient magnetic separation versus expanded bed adsorption: a first principle comparison

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Matthiesen, D.B.; Hobley, Timothy John

    2001-01-01

    A robust new adsorptive separation technique specifically designed for direct product capture from crude bioprocess feedstreams is introduced and compared with the current bench mark technique, expanded bed adsorption. The method employs product adsorption onto sub-micron sized non...... system exhibited substantially enhanced productivity over expanded bed adsorption when operated at processing velocities greater than 48 m h(-1). Use of the bacitracin- linked magnetic supports for a single cycle of batch adsorption and subsequent capture by high gradient magnetic separation...... at a processing rate of 12 m h(-1) resulted in a 2.2-fold higher productivity relative to expanded bed adsorption, while an increase in adsorbent collection rate to 72 m h(-1) raised the productivity to 10.7 times that of expanded bed adsorption. When the number of batch adsorption cycles was then increased...

  4. A biocompatible and novelly-defined Al-HAP adsorption membrane for highly effective removal of fluoride from drinking water.

    Science.gov (United States)

    He, Junyong; Chen, Kai; Cai, Xingguo; Li, Yulian; Wang, Chengming; Zhang, Kaisheng; Jin, Zhen; Meng, Fanli; Wang, Xuguang; Kong, Lingtao; Liu, Jinhuai

    2017-03-15

    A biocompatible and novelly-defined adsorption membrane for rapid removal of fluoride was prepared. Both adsorption and membrane techniques were used in this research. Al(OH)3 nanoparticles modified hydroxyapatite (Al-HAP) nanowires were developed and made into Al-HAP membrane. The adsorption data of Al-HAP adsorbent could be well described by Freundlich isotherm model while the adsorption kinetic followed pseudo-second-order model. The maximum of adsorption capacity was 93.84mg/g when the fluoride concentration was 200mg/L. The adsorption mechanism was anion exchanges and electrostatic interactions. The contribution rates of HAP nanowires and Al(OH)3 nanoparticles in fluoride removal were 36.70% and 63.30%, respectively. The fixed-bed column test demonstrate that the Al-HAP was biocompatible and in a good stability during the process of water treatment. The fluoride removal abilities of Al-HAP membrane with 0.3mm thickness could reach 1568L/m(2) when fluoride concentrations were 5mg/L. This study indicated that the Al-HAP membrane could be developed into a very viable technology for highly effective removal of fluoride from drinking water. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Amine-functionalized PVA-co-PE nanofibrous membrane as affinity membrane with high adsorption capacity for bilirubin.

    Science.gov (United States)

    Wang, Wenwen; Zhang, Hao; Zhang, Zhifeng; Luo, Mengying; Wang, Yuedan; Liu, Qiongzhen; Chen, Yuanli; Li, Mufang; Wang, Dong

    2017-02-01

    In this study, poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membrane was activated by sodium hydroxide and cyanuric chloride, and then the activated membranes were functionalized by 1,3-propanediamine, hexamethylenediamine and diethylenetriamine to be affinity membranes for bilirubin removal, respectively. The chemical structures and morphologies of membranes were investigated by SEM, FTIR and XPS. And the adsorption ability of different amine-functionalized nanofibrous membranes for bilirubin was characterized. Furthermore, the effects of temperature, initial concentration of bilirubin, NaCl concentration and BSA concentration on the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane were studied. Results indicated that the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane could reach 85mg/g membrane when the initial bilirubin concentration was 200mg/L while the adsorption capacity could be increased to 110mg/g membrane if the initial bilirubin concentration was more than 400mg/L. The dynamic adsorption of diethylenetriamine-functionalized nanofibrous membrane showed that the ligands of amine groups on the membrane surface could be used as far as possible by recirculating the plasma with certain flow rates. Therefore, the diethylenetriamine-functionalized PVA-co-PE nanofibrous membrane possessed high adsorption capacity for bilirubin and it can be candidate as affinity membrane for bilirubin removal.

  6. Lessons Learned from Working with High-Ability Students

    Science.gov (United States)

    Pfeiffer, Steven I.

    2013-01-01

    This article discusses three lessons that stand out as particularly poignant in the author's career working with high-ability students. The author recounts personal and professional experiences that influenced his thinking. The three lessons are that identifying high-ability students is not an easy business, the development of talent requires more…

  7. Unconventional, highly selective CO2 adsorption in zeolite SSZ-13.

    Science.gov (United States)

    Hudson, Matthew R; Queen, Wendy L; Mason, Jarad A; Fickel, Dustin W; Lobo, Raul F; Brown, Craig M

    2012-02-01

    Low-pressure adsorption of carbon dioxide and nitrogen was studied in both acidic and copper-exchanged forms of SSZ-13, a zeolite containing an 8-ring window. Under ideal conditions for industrial separations of CO(2) from N(2), the ideal adsorbed solution theory selectivity is >70 in each compound. For low gas coverage, the isosteric heat of adsorption for CO(2) was found to be 33.1 and 34.0 kJ/mol for Cu- and H-SSZ-13, respectively. From in situ neutron powder diffraction measurements, we ascribe the CO(2) over N(2) selectivity to differences in binding sites for the two gases, where the primary CO(2) binding site is located in the center of the 8-membered-ring pore window. This CO(2) binding mode, which has important implications for use of zeolites in separations, has not been observed before and is rationalized and discussed relative to the high selectivity for CO(2) over N(2) in SSZ-13 and other zeolites containing 8-ring windows.

  8. Synthesis, characterization and dye removal ability of high capacity polymeric adsorbent: Polyaminoimide homopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoodi, Niyaz Mohammad, E-mail: nm_mahmoodi@aut.ac.ir [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Najafi, Farhood [Department of Resin and Additives, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Khorramfar, Shooka [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Amini, Farrokhlegha [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Arami, Mokhtar [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Polyaminoimide homopolymer (PAIHP) was synthesized and characterized. Black-Right-Pointing-Pointer Kinetics data followed pseudo-second order kinetic model. Black-Right-Pointing-Pointer Isotherm data followed Langmuir isotherm. Black-Right-Pointing-Pointer Q{sub 0} for DR31, DR23, DB22 and AB25 was 6667, 5555, 9090 and 5882 mg/g, respectively. Black-Right-Pointing-Pointer PAIHP was regenerated at pH 12. - Abstract: In this paper, polyaminoimide homopolymer (PAIHP) was synthesized and its dye removal ability was investigated. Physical characteristics of PAIHP were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Direct Red 31 (DR31), Direct Red 23 (DR23), Direct Black 22 (DB22) and Acid Blue 25 (AB25) were used as model compounds. The kinetic and isotherm of dye adsorption were studied. The effect of operational parameter such as adsorbent dosage, pH and salt on dye removal was evaluated. Adsorption kinetic of dyes followed pseudo-second order kinetics. The maximum dye adsorption capacity (Q{sub 0}) of PAIHP was 6667 mg/g, 5555 mg/g, 9090 mg/g and 5882 mg/g for DR31, DR23, DB22 and AB25, respectively. It was found that adsorption of DR31, DR23, DB22 and AB25 onto PAIHP followed with Langmuir isotherm. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% for DR31, 86% for DR23, 87% for DB22 and 90% for AB25 were achieved in aqueous solution at pH 12. The results showed that the PAIHP as a polymeric adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored wastewater.

  9. Dithiocarbamate-modified starch derivatives with high heavy metal adsorption performance.

    Science.gov (United States)

    Xiang, Bo; Fan, Wen; Yi, Xiaowei; Wang, Zuohua; Gao, Feng; Li, Yijiu; Gu, Hongbo

    2016-01-20

    In this work, three types of dithiocarbamate (DTC)-modified starch derivatives including DTC starch (DTCS), DTC enzymolysis starch (DTCES) and DTC mesoporous starch (DTCMS) were developed, which showed the significant heavy metal adsorption performance. The adsorption ability of these three DTC modified starch derivatives followed the sequences: DTCMS>DTCES>DTCS. In single metal aqueous solutions, the uptake amount of heavy metal ions onto the modified starches obeyed the orders: Cu(II)>Ni(II)>Cr(VI)>Zn(II)>Pb(II). The adsorption mechanism was proved by the chelating between DTC groups and heavy metal ions through the pH effect measurements. A monolayer adsorption of Langmuir isotherm model for the adsorption of Cu(II) onto DTCMS was well fitted rather than the multilayer adsorption of Freundlich isotherm model. The adsorption kinetics of Cu(II) onto starch derivatives was found to be fit well with the pseudo-second-order model. Additionally, in the presence of EDTA, the adsorption ability and uptake amount of heavy metal ions onto these three DTC modified starch derivatives is identical with the results obtained in the absence of EDTA.

  10. Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes.

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-21

    The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g(-1) and 1084.5 mg·g(-1) for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

  11. Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-01

    The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg.g-1 and 1084.5 mg.g-1 for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

  12. Hierarchically porous silicon–carbon–nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-01

    The hierarchically macro/micro-porous silicon–carbon–nitrogen (Si–C–N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp2-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g−1 and 1084.5 mg·g−1 for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si–C–N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants. PMID:25604334

  13. My opinion on upgrading high school English learning ability

    Institute of Scientific and Technical Information of China (English)

    Geng yusi

    2016-01-01

    Nowadays, English has become the difficult problems for high school students to overcome. This article begins with the cultivation of English, and then from the perspectives of grammar, vocabulary, pronunciation and listening ability to discuss the enhancement of English ability of the students.

  14. AgII doped MIL-101 and its adsorption of iodine with high speed in solution

    Science.gov (United States)

    Mao, Ping; Qi, Bingbing; Liu, Ying; Zhao, Lei; Jiao, Yan; Zhang, Yi; Jiang, Zheng; Li, Qiang; Wang, Jinfeng; Chen, Shouwen; Yang, Yi

    2016-05-01

    In order to improve the adsorption speed of iodine from water, MIL-101 with extra-large specific surface area (3054 m2/g) was chosen as a base material, and then, Ag was doped into MIL-101 to enhance its adsorption capacity through an incipient-wetness impregnation method. With the characterization of SEM-EDS, TEM, XRD, XPS, TGA, IR, and BET techniques, the resulting Ag was identified to be stay in the framework of MIL-101 stably in the form of AgII (generally, AgII cation is not stable). However, after the adsorption of I- anions, AgII stay in the cages of MIL-101 in the form of AgI/AgI3. It is important to note that, all adsorbents show high adsorption speed of iodine in solution. The equilibrium adsorption time of the adsorbents were acquired by only a few minutes, which can be attributed to its large BET surface area. An interesting note is that, when the doping amount of Ag is less than 9%, the iodine anions adsorption capacity of Ag@MIL-101 is greater than its theoretical adsorption capacity. It shows that both physical adsorption and chemical adsorption are existed in the adsorption process. This study hopefully leads to a new and highly efficient Ag-based adsorbent for iodide adsorb from solutions.

  15. High capacity adsorption media and method of producing

    Science.gov (United States)

    Tranter, Troy J.; Mann, Nicholas R.; Todd, Terry A.; Herbst, Ronald S.

    2010-10-05

    A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving and/or suspending at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.

  16. Desirable characteristics for teachers of High Ability/Gifted students

    Directory of Open Access Journals (Sweden)

    Alexandra da Costa Souza Martins

    2011-06-01

    Full Text Available This study investigated the desirable educational background for a teacher to work with high ability/gifted students, desirable characteristics these teachers should present and conceptions on high ability/giftedness. The participants were 20 public school teachers from a city surrounding Brasilia. Of this group, ten were elementary school teachers working with initial grades and ten were undergraduate Pedagogy teachers. A qualitative approach was used and data were collected by means of a semi-structured interview. A content analysis was then conducted. In relation to the desirable educational background for a teach of high ability/gifted students, participants indicated the need of continuous training, under graduation curriculum adapted to the theme and graduation courses in the area. The desirable features for teachers of high ability/gifted students were related to personological attributes (personality traits and intellectual ability, as well as professional characteristics. The conceptions on high ability/giftedness presented by the participants were, in general, close to those found in the literature and used as reference for this study. However, there was lack of information on how to apply the theory into real practice, as well as several wrong ideas on the topic.

  17. Adsorptive Removal of Pharmaceuticals and Personal Care Products from Water with Functionalized Metal-organic Frameworks: Remarkable Adsorbents with Hydrogen-bonding Abilities

    Science.gov (United States)

    Seo, Pill Won; Bhadra, Biswa Nath; Ahmed, Imteaz; Khan, Nazmul Abedin; Jhung, Sung Hwa

    2016-10-01

    Adsorption of typical pharmaceuticals and personal care products (PPCPs) (such as naproxen, ibuprofen and oxybenzone) from aqueous solutions was studied by using the highly porous metal-organic framework (MOF) MIL-101 with and without functionalization. Adsorption results showed that MIL-101s with H-donor functional groups such as -OH and -NH2 were very effective for naproxen adsorption, despite a decrease in porosity, probably because of H-bonding between O atoms on naproxen and H atoms on the adsorbent. For this reason, MIL-101 with two functional groups capable of H-bonding (MIL-101-(OH)2) exhibited remarkable adsorption capacity based on adsorbent surface area. The favorable contributions of -OH and -(OH)2 on MIL-101 in the increased adsorption of ibuprofen and oxybenzone (especially based on porosity) confirmed again the importance of H-bonding mechanism. The adsorbent with the highest adsorption capacity, MIL-101-OH, was very competitive when compared with carbonaceous materials, mesoporous materials, and pristine MIL-101. Moreover, the MIL-101-OH could be recycled several times by simply washing with ethanol, suggesting potential application in the adsorptive removal of PPCPs from water.

  18. Adsorptive Removal of Pharmaceuticals and Personal Care Products from Water with Functionalized Metal-organic Frameworks: Remarkable Adsorbents with Hydrogen-bonding Abilities

    Science.gov (United States)

    Seo, Pill Won; Bhadra, Biswa Nath; Ahmed, Imteaz; Khan, Nazmul Abedin; Jhung, Sung Hwa

    2016-01-01

    Adsorption of typical pharmaceuticals and personal care products (PPCPs) (such as naproxen, ibuprofen and oxybenzone) from aqueous solutions was studied by using the highly porous metal-organic framework (MOF) MIL-101 with and without functionalization. Adsorption results showed that MIL-101s with H-donor functional groups such as –OH and –NH2 were very effective for naproxen adsorption, despite a decrease in porosity, probably because of H-bonding between O atoms on naproxen and H atoms on the adsorbent. For this reason, MIL-101 with two functional groups capable of H-bonding (MIL-101-(OH)2) exhibited remarkable adsorption capacity based on adsorbent surface area. The favorable contributions of –OH and –(OH)2 on MIL-101 in the increased adsorption of ibuprofen and oxybenzone (especially based on porosity) confirmed again the importance of H-bonding mechanism. The adsorbent with the highest adsorption capacity, MIL-101-OH, was very competitive when compared with carbonaceous materials, mesoporous materials, and pristine MIL-101. Moreover, the MIL-101-OH could be recycled several times by simply washing with ethanol, suggesting potential application in the adsorptive removal of PPCPs from water. PMID:27695005

  19. Setting the Bar for High-Ability Students

    Science.gov (United States)

    Greene, Buck; Cross, Tracy L.

    2013-01-01

    Secondary school principals face no shortage of issues and challenges when it comes to ensuring that their teachers and students are ready for the Common Core State Standards. With so many issues competing for scarce time and resources, it is understandable that for many school leaders, the needs of high-ability and high-potential students are not…

  20. Selective adsorption of protein by a high-efficiency Cu(2+) -cooperated magnetic imprinted nanomaterial.

    Science.gov (United States)

    Shi, Lu; Tang, Yuhai; Hao, Yi; He, Gaiyan; Gao, Ruixia; Tang, Xiaoshuang

    2016-07-01

    We report a core-shell magnetic molecularly imprinted polymer with high affinity through a facile sol-gel method for the selective adsorption of bovine hemoglobin from real bovine blood. Copper ions grafted on the surface of the matrix could immobilize template protein through chelation, which greatly enhances the orderliness of imprinted cavities and affinity of polymers. The obtained products exhibit a desired level of magnetic susceptibility, resulting in the highly efficient adsorption process. The results of adsorption experiments show that the saturation adsorption capacity of imprinted products could reach 116.3 mg/g within 30 min. Meanwhile, the specific binding experiment demonstrates the high selectivity of polymers for bovine hemoglobin. Furthermore, satisfactory reusability is demonstrated by ten adsorption-desorption cycles with no obvious deterioration in binding capacity. Electrophoretic analysis suggests the polymer could be used successfully in separation and enrichment of bovine hemoglobin from the bovine blood sample, which exhibits potential application in pretreatment of proteomics.

  1. Cobalt nanoparticles-embedded magnetic ordered mesoporous carbon for highly effective adsorption of rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Cai, Ye; Yang, Guide; Liu, Yuanyuan [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Zhou, Yaoyu; Li, Sisi; Wang, Jiajia; Zhang, Sheng; Fang, Yan; He, Yibin [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2014-09-30

    Highlights: • Cobalt nanoparticles-embedded magnetic ordered mesoporous carbon (Co/OMC) was applied as a novel adsorption material to remove rhodamine B. • Co/OMC was synthesized by directly introducing cobalt into OMC through a simple infusing method. • High removal capacity of rhodamine B: maximum adsorption capacity reaches 468 mg/g at 200 mg/L initial rhodamine B concentration. • Very quick adsorption property: 96% of rhodamine B can be removed within 25 min. - Abstract: Cobalt nanoparticles-embedded magnetic ordered mesoporous carbon (Co/OMC), prepared through a simple method involving infusing and calcination, was used as a highly effective adsorbent for rhodamine B (Rh B) removal. Several techniques, including SEM, HRTEM, nitrogen adsorption–desorption isotherms, XRD, Raman spectra, EDX, zeta potential and VSM measurement, were applied to characterize the adsorbent. Batch tests were conducted to investigate the adsorption performance. The adsorption capacity of the resultant adsorbent was relatively high compared with raw ordered mesoporous carbon (OMC) and reached an equilibrium value of 468 mg/g at 200 mg/L initial Rh B concentration. Removal efficiency even reached 96% within 25 min at 100 mg/L initial Rh B concentration. Besides, the adsorption amount increased with the increase of solution pH, adsorbent dose and initial Rh B concentration. Kinetics study showed that the adsorption agreed well with pseudo-second-order model (R{sup 2} = 0.999) and had a significant correlation with intra-particle diffusion model in the both two adsorption periods. Furthermore, thermodynamics research indicated that the adsorption process was endothermic and spontaneous in nature. The adsorption isotherms fitted well with Langmuir model, demonstrating the formation of mono-molecular layer on the surface of Co/OMC during adsorption process. The results confirmed that Co/OMC has the potential superiority in removal of Rh B from aqueous solution.

  2. Equilibrium, kinetic and thermodynamic study of cesium adsorption onto nanocrystalline mordenite from high-salt solution.

    Science.gov (United States)

    Lee, Keun-Young; Park, Minsung; Kim, Jimin; Oh, Maengkyo; Lee, Eil-Hee; Kim, Kwang-Wook; Chung, Dong-Yong; Moon, Jei-Kwon

    2016-05-01

    In this study, the equilibrium, kinetics and thermodynamics of cesium adsorption by nanocrystalline mordenite were investigated under cesium contamination with high-salt solution, simulating the case of an operation and decommissioning of nuclear facilities or an accident during the processes. The adsorption rate constants were determined using a pseudo second-order kinetic model. The kinetic results strongly demonstrated that the cesium adsorption rate of nano mordenite is extremely fast, even in a high-salt solution, and much faster than that of micro mordenite. In the equilibrium study, the Langmuir isotherm model fit the cesium adsorption data of nano mordenite better than the Freundlich model, which suggests that cesium adsorption onto nano mordenite is a monolayer homogeneous adsorption process. The obtained thermodynamic parameters indicated that the adsorption involved a very stable chemical reaction. In particular, the combination of rapid particle dispersion and rapid cesium adsorption of the nano mordenite in the solution resulted in a rapid and effective process for cesium removal without stirring, which may offer great advantages for low energy consumption and simple operation.

  3. Teaching High-Ability Pupils in Early Primary School

    NARCIS (Netherlands)

    Dijkstra, Elma

    2015-01-01

    This thesis describes the design and implementation of the intervention 'Excel Kwadraat' in primary schools. This intervention aims to improve teachers’ differentiation practices in order to better anticipate pupil differences, including excellent or high-ability pupils. In the end, the intervention

  4. Teaching High-Ability Pupils in Early Primary School

    NARCIS (Netherlands)

    Dijkstra, Elma

    2015-01-01

    This thesis describes the design and implementation of the intervention 'Excel Kwadraat' in primary schools. This intervention aims to improve teachers’ differentiation practices in order to better anticipate pupil differences, including excellent or high-ability pupils. In the end, the intervention

  5. Identity Development of High-Ability Black Collegians.

    Science.gov (United States)

    Fries-Britt, Sharon

    2000-01-01

    Discusses the difficulties that high-ability black college students face in blending their academic interest and racial affiliation into their sense of self. Student narratives show how a strong peer community and positive student-faculty interactions can overcome these obstacles and promote healthy identity development. (Author/DB)

  6. High-Ability Students' Time Spent outside the Classroom

    Science.gov (United States)

    Makel, Matthew C.; Li, Yan; Putallaz, Martha; Wai, Jonathan

    2011-01-01

    This study considered how three groups of academically talented high school students--those who attended an academic summer program (TIP), those who qualified for the program but chose not to attend (QNA), and those who did not qualify (DNQ)--spent time outside the classroom. These groupings differentiated students by ability (QNA vs. DNQ) and…

  7. Social and emotional difficulties among high ability students

    Directory of Open Access Journals (Sweden)

    Eunice Soriano de Alencar

    2008-06-01

    Full Text Available Social and emotional difficulties observed among highly able students are addressed. The asynchronous development, perfectionism, over-excitability, underachievement, and other social and emotional difficulties are discussed, describing factors related to them. The article finalizes highlighting possible contributions of the psychologist on counseling high ability students, their families and teachers, with the purpose of preventing or reducing maladjustments, as well as of helping them optimize their developmental process.

  8. Synthesis of Iron Doped Zeolite Imidazolate Framework-8 and Its Remazol Deep Black RGB Dye Adsorption Ability

    Directory of Open Access Journals (Sweden)

    Mai Thi Thanh

    2017-01-01

    Full Text Available Zeolite imidazole framework-8 (ZIF-8 and the iron doped ZIF-8 (Fe-ZIF-8 were synthesized by the hydrothermal process. The obtained materials were characteristic of X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, scanning electron microscope (SEM, nitrogen adsorption/desorption isotherms, and atomic absorption spectroscopy (AAS. The results showed that the obtained Fe-ZIF-8 possessed the ZIF-8 structure with a large specific area. ZIF-8 and Fe-ZIF-8 were used for the removal of Remazol Deep Black (RDB RGB dye from aqueous solutions. The various factors affecting adsorption such as pH, initial concentration, contact time, and temperature were investigated. The results showed that the introduction of iron into ZIF-8 provided a much larger adsorption capacity and faster adsorption kinetics than ZIF-8 without iron. The electrostatic interaction and π-π interaction between the aromatic rings of the RDB dye and the aromatic imidazolate rings of the adsorbent were responsible for the RDB adsorption. Moreover, the coordination of the nitrogen atoms and oxygen in carboxyl group in RDB molecules with the Fe2+ ions in the ZIF-8 framework played a vital role for the effective removal of RDB from aqueous solution.

  9. [Psychoeducational intervention in high ability: intellectual functioning and extracurricular enrichment].

    Science.gov (United States)

    Sastre-Riba, Sylvia

    2014-02-24

    The 'new paradigm' defines the high intellectual ability as a potential that should crystallize progressively throughout development. Its main feature is a high intellectual initial multidimensional potential, which is transformed so that, being a person with high intellectual ability is the result of a developmental process from a neurobiological substrate and the incidence of variables (psychosocial and education) which determines its manifestation more or less stable and optimal to excellence. It is interesting to know the effectiveness of psychoeducational intervention of the extracurricular enrichment programs and their effects on the expression of differential functioning and the optimization of the management of cognitive resources that lead to excellence. An extracurricular enrichment program is described and evaluated through: 1) the stability of the intellectual measures; 2) the satisfaction level of participants and families. Participants are 58 high ability students on the enrichment program and 25 parents. Intellectual profiles are obtained on T1-T2 and calculated their stability by regression analysis, the CSA and CSA-P questionnaires were applied in order to know the participants and families' satisfaction measure. Results show the basic stability of intellectual profiles with five cases of instability among the 58 profiles obtained, and a high satisfaction with the results obtained in the domain of cognitive and personal management among the participants.

  10. Verbal abilities in low and highly proficient bilinguals.

    Science.gov (United States)

    Andreou, Georgia; Karapetsas, Anargyros

    2004-09-01

    The study investigated native language verbal skills among low and highly proficient bilinguals, using the WISC III verbal subtests. Highly proficient bilinguals showed a superiority for almost all verbal subtests. This finding lends support to Threshold Theory which maintains that bilinguals need to achieve high levels of linguistic proficiency before bilingualism can promote cognitive development. Our study also shows that verbal ability underlying proficiency in the native language can be generalized to a foreign language, revealing a causal connection between native and foreign language learning.

  11. [High ability children and their differential cognitive functioning].

    Science.gov (United States)

    Sastre-Riba, S

    2008-01-01

    From the neuroconstructivist point of view, cognitive development is understood as a process of successive and continuous reorganization whose changing mechanisms and differential outcomes (typical and atypical) must be studied. High intellectual abilities are one of their differential manifestations but its concept and nature is confused conditioning the validity of its identification and the efficacy of the interventional programs. To propose a clarifying definition of the nature of high intellectual abilities and their manifestations: giftedness, talent and genious, as well as their cognitive functioning and neurological correlates. A qualitative task analysis is applied to 41 participants with intellectual profiles corresponding to: giftedness, talent and typical intelligence, previously obtained. Results show differences on the cognitive results, not only referred to the quantity of informations produced but in the data organization more complex and hard interrelated among the gifted participants. It must be a differential process of resolution adjusted to each one of the profiles studied.

  12. Identifying high ability students: a contribution from neuropsychological indicators

    OpenAIRE

    Dora Cortat Simonetti; Leandro S. Almeida; Zenita Guenther

    2010-01-01

    This paper presents some data on the convergence between psychometric intelligence measurements (IQ tests) and physiological signs of mental activity found in high ability adolescents. The research study focus on a small group of 15 subjects submitted to electric encephalograms, previously chosen from a larger group of 77 classmates on the basis of scores on the WISC-III IQ Test. The results suggest continuous predominance of Alpha waves for the gifted group (higher frequency percentile and h...

  13. High CO2-capture ability of a porous organic polymer bifunctionalized with carboxy and triazole groups.

    Science.gov (United States)

    Xie, Lin-Hua; Suh, Myunghyun Paik

    2013-08-26

    A new porous organic polymer, SNU-C1, incorporating two different CO2 -attracting groups, namely, carboxy and triazole groups, has been synthesized. By activating SNU-C1 with two different methods, vacuum drying and supercritical-CO2 treatment, the guest-free phases, SNU-C1-va and SNU-C1-sca, respectively, were obtained. Brunauer-Emmett-Teller (BET) surface areas of SNU-C1-va and SNU-C1-sca are 595 and 830 m(2) g(-1), respectively, as estimated by the N2-adsorption isotherms at 77 K. At 298 K and 1 atm, SNU-C1-va and SNU-C1-sca show high CO2 uptakes, 2.31 mmol  g(-1) and 3.14 mmol  g(-1), respectively, the high level being due to the presence of abundant polar groups (carboxy and triazole) exposed on the pore surfaces. Five separation parameters for flue gas and landfill gas in vacuum-swing adsorption were calculated from single-component gas-sorption isotherms by using the ideal adsorbed solution theory (IAST). The data reveal excellent CO2-separation abilities of SNU-C1-va and SNU-C1-sca, namely high CO2-uptake capacity, high selectivity, and high regenerability. The gas-cycling experiments for the materials and the water-treated samples, experiments that involved treating the samples with a CO2-N2 gas mixture (15:85, v/v) followed by a pure N2 purge, further verified the high regenerability and water stability. The results suggest that these materials have great potential applications in CO2 separation.

  14. Adsorption behavior of perfluorinated sulfonic acid ionomer on highly graphitized carbon nanofibers and their thermal stabilities

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Borghei, Maryam; Dhiman, Rajnish

    2014-01-01

    isotherm), the ionomer has varying affinities for CNFs (Keq. = between 5 and 22) as compared to Vulcan (Keq. = 18), depending on surface treatments. However, the interactions are most likely governed by different adsorption mechanisms depending on hydrophilicity / hydrophobicity of the adsorbent carbon......A systematic adsorption study of perfluorinated sulfonic acid Nafion® ionomer on ribbon type highly graphitized carbon nanofibers (CNFs) was carried out using 19 fluorine nuclear magnetic resonance spectroscopy. Based on the values obtained for the equilibrium constant (Keq., derived from Langmuir....... The ionomer is probably adsorbed via the polar sulfonic group on hydrophilic Vulcan, whereas, it is adsorbed primarily via hydrophobic -CF2- backbone on the highly hydrophobic pristine CNFs. Ionomer adsorption behavior is gradually altered from apolar to polar group adsorption for the acid modified CNFs...

  15. Identifying high ability students: a contribution from neuropsychological indicators

    Directory of Open Access Journals (Sweden)

    Dora Cortat Simonetti

    2010-06-01

    Full Text Available This paper presents some data on the convergence between psychometric intelligence measurements (IQ tests and physiological signs of mental activity found in high ability adolescents. The research study focus on a small group of 15 subjects submitted to electric encephalograms, previously chosen from a larger group of 77 classmates on the basis of scores on the WISC-III IQ Test. The results suggest continuous predominance of Alpha waves for the gifted group (higher frequency percentile and higher amplitude what was not observed in the group without any superior intellectual ability. Even taking into account methodological limitations, this study may contribute to the understanding of a relationship between the intellectual quotient (IQ and alpha waves frequency and amplitude, as observed during performance on cognitive tasks. Such results may suggest a possibility to complement psychometric measures with encephalic registers in giftedness research studies.

  16. Neptunium(V) Adsorption to Bacteria at Low and High Ionic Strength

    Science.gov (United States)

    Ams, D.; Swanson, J. S.; Reed, D. T.

    2010-12-01

    Np(V) is expected to be the predominant oxidation state of neptunium in aerobic natural waters. Np(V), as the NpO2+ aquo and associated complexed species, is readily soluble, interacts weakly with geologic media, and has a high redox stability under a relatively wide range of subsurface conditions. These chemical properties, along with a long half-life make it a primary element of concern regarding long-term nuclear waste storage and subsurface containment. The fate and transport of neptunium in the environment may be influenced by adsorption onto bacterial surfaces. The adsorption of neptunium to bacterial surfaces ties the mobility of the contaminant to the mobility of the bacterium. In this study, the adsorption of the neptunyl (NpO2+) ion was evaluated at low ionic strength on a common soil bacterium and at high ionic strength on a halophilic bacterium isolated from a briny groundwater near the Waste Isolation Pilot Plant (WIPP) in southeast New Mexico. Adsorption experiments were performed in batch reactors as a function of pH, ionic strength, and bacteria/Np mass ratio. Np(V) adsorption was modeled using a surface complexation approach with the mathematical program FITEQL to determine functional group specific binding constants. The data from acid and base titrations of the bacteria used were also modeled to estimate the concentrations and deprotonation constants of discrete bacterial surface functional groups. Bacterial functional group characteristics and Np(V) adsorption behavior between the soil bacterium and the halophilic bacterium were compared. These results highlight key similarities and differences in actinide adsorption behavior in environments of significantly different ionic strength. The observed adsorption behavior may be linked to similarities and differences in the characteristics of the moieties between the cell walls of common gram-negative soil and halophilic bacteria. Moreover, differences in adsorption behavior may also reflect ionic

  17. Highly crystallized nanometer-sized zeolite a with large Cs adsorption capability for the decontamination of water.

    Science.gov (United States)

    Torad, Nagy L; Naito, Masanobu; Tatami, Junichi; Endo, Akira; Leo, Sin-Yen; Ishihara, Shinsuke; Wu, Kevin C-W; Wakihara, Toru; Yamauchi, Yusuke

    2014-03-01

    Nanometer-sized zeolite A with a large cesium (Cs) uptake capability is prepared through a simple post-milling recrystallization method. This method is suitable for producing nanometer-sized zeolite in large scale, as additional organic compounds are not needed to control zeolite nucleation and crystal growth. Herein, we perform a quartz crystal microbalance (QCM) study to evaluate the uptake ability of Cs ions by zeolite, to the best of our knowledge, for the first time. In comparison to micrometer-sized zeolite A, nanometer-sized zeolite A can rapidly accommodate a larger amount of Cs ions into the zeolite crystal structure, owing to its high external surface area. Nanometer-sized zeolite is a promising candidate for the removal of radioactive Cs ions from polluted water. Our QCM study on Cs adsorption uptake behavior provides the information of adsorption kinetics (e.g., adsorption amounts and rates). This technique is applicable to other zeolites, which will be highly valuable for further consideration of radioactive Cs removal in the future.

  18. Mn(II)-based porous metal-organic framework showing metamagnetic properties and high hydrogen adsorption at low pressure.

    Science.gov (United States)

    Han, Zheng-Bo; Lu, Rui-Yun; Liang, Yan-Fang; Zhou, Yan-Ling; Chen, Qing; Zeng, Ming-Hua

    2012-01-02

    A Mn(II)-based homometallic porous metal-organic framework, Mn(5)(btac)(4)(μ(3)-OH)(2)(EtOH)(2)·DMF·3EtOH·3H(2)O (1, btac = benzotriazole-5-carboxylate), has been solvothermally synthesized and structurally characterized by elemental analysis, thermogravimetric analysis, and X-ray crystallographic study. 1 is a 3D neutral framework featuring 1D porous channels constructed by {Mn-OH-Mn}(n) chains and btac linkers. Magnetic studies show that 1 is a 3D metamagnet containing 1D {Mn-OH-Mn}(n) ferrimagnetic chains. High-pressure H(2) adsorption measurement at 77 K reveals that activated 1 can absorb 0.99 wt % H(2) at 0.5 atm and reaches a maximum of 1.03 wt % at 5.5 atm. The steep H(2) absorption at lower pressure (98.2% of the storage capacity at 0.5 atm) is higher than the corresponding values of some MOFs (MIL-100 (16.1%), MOF-177 (57.1%), and MOF-5 (22.2%)). Furthermore, activated 1 can adsorb CO(2) at room temperature and 275 K. The adsorption enthalpy is 22.0 kJ mol(-1), which reveals the high binding ability for CO(2). Detailed gas sorption implies that the exposed Mn(II) coordination sites in the activated 1 play an important role to improve its adsorption capacities.

  19. Mechanisms of Antigen Adsorption Onto an Aluminum-Hydroxide Adjuvant Evaluated by High-Throughput Screening.

    Science.gov (United States)

    Jully, Vanessa; Mathot, Frédéric; Moniotte, Nicolas; Préat, Véronique; Lemoine, Dominique

    2016-06-01

    The adsorption mechanism of antigen on aluminum adjuvant can affect antigen elution at the injection site and hence the immune response. Our aim was to evaluate adsorption onto aluminum hydroxide (AH) by ligand exchange and electrostatic interactions of model proteins and antigens, bovine serum albumin (BSA), β-casein, ovalbumin (OVA), hepatitis B surface antigen, and tetanus toxin (TT). A high-throughput screening platform was developed to measure adsorption isotherms in the presence of electrolytes and ligand exchange by a fluorescence-spectroscopy method that detects the catalysis of 6,8-difluoro-4-methylumbelliferyl phosphate by free hydroxyl groups on AH. BSA adsorption depended on predominant electrostatic interactions. Ligand exchange contributes to the adsorption of β-casein, OVA, hepatitis B surface antigen, and TT onto AH. Based on relative surface phosphophilicity and adsorption isotherms in the presence of phosphate and fluoride, the capacities of the proteins to interact with AH by ligand exchange followed the trend: OVA < β-casein < BSA < TT. This could be explained by both the content of ligands available in the protein structure for ligand exchange and the antigen's molecular weight. The high-throughput screening platform can be used to better understand the contributions of ligand exchange and electrostatic attractions governing the interactions between an antigen adsorbed onto aluminum-containing adjuvant. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Water adsorption at high temperature on core samples from The Geysers geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal reservoir, California, was measured at 150, 200, and 250 C as a function of pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there is in general no proportionality between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The results indicate that multilayer adsorption rather than capillary condensation is the dominant water storage mechanism at high temperatures.

  1. The ability of endotoxin adsorption during a longer duration of direct hemoperfusion with a polymyxin B-immobilized fiber column in patients with septic shock.

    Science.gov (United States)

    Shimizu, Tomoharu; Obata, Toru; Sonoda, Hiromichi; Akabori, Hiroya; Tabata, Takahisa; Eguchi, Yutaka; Endo, Yoshihiro; Tani, Tohru

    2013-12-01

    The patients' hemodynamic conditions of septic shock due to intra-abdominal infection were improved by the longer duration of direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX), reducing plasma endotoxins measured by the novel endotoxin detection method, named endotoxin scattering photometry (ESP) method; however, turbidimetric method could not detect endotoxins. We also observed the reduction in the endotoxin after passing through column by ESP method even after the longer duration of PMX. ESP method may more sensitively detect endotoxins than the ordinary turbidimetric method. Moreover, we demonstrated the ability of endotoxin adsorption in spite of the longer duration of PMX.

  2. CoFe2O4@MIL-100(Fe) hybrid magnetic nanoparticles exhibit fast and selective adsorption of arsenic with high adsorption capacity

    Science.gov (United States)

    Yang, Ji-Chun; Yin, Xue-Bo

    2017-01-01

    In this study, we report the synthesis and application of mesoporous CoFe2O4@MIL-100(Fe) hybrid magnetic nanoparticles (MNPs) for the simultaneous removal of inorganic arsenic (iAs). The hybrid adsorbent had a core-shell and mesoporous structure with an average diameter of 260 nm. The nanoscale size and mesoporous character impart a fast adsorption rate and high adsorption capacity for iAs. In total, 0.1 mg L−1 As(V) and As(III) could be adsorbed within 2 min, and the maximum adsorption capacities were 114.8 mg g−1 for As(V) and 143.6 mg g−1 for As(III), higher than most previously reported adsorbents. The anti-interference capacity for iAs adsorption was improved by the electrostatic repulsion and size exclusion effects of the MIL-100(Fe) shell, which also decreased the zero-charge point of the hybrid absorbent for a broad pH adsorption range. The adsorption mechanisms of iAs on the MNPs are proposed. An Fe-O-As structure was formed on CoFe2O4@MIL-100(Fe) through hydroxyl substitution with the deprotonated iAs species. Monolayer adsorption of As(V) was observed, while hydrogen bonding led to the multi-layer adsorption of neutral As(III) for its high adsorption capacity. The high efficiency and the excellent pH- and interference-tolerance capacities of CoFe2O4@MIL-100(Fe) allowed effective iAs removal from natural water samples, as validated with batch magnetic separation mode and a portable filtration strategy. PMID:28102334

  3. CoFe2O4@MIL-100(Fe) hybrid magnetic nanoparticles exhibit fast and selective adsorption of arsenic with high adsorption capacity

    Science.gov (United States)

    Yang, Ji-Chun; Yin, Xue-Bo

    2017-01-01

    In this study, we report the synthesis and application of mesoporous CoFe2O4@MIL-100(Fe) hybrid magnetic nanoparticles (MNPs) for the simultaneous removal of inorganic arsenic (iAs). The hybrid adsorbent had a core-shell and mesoporous structure with an average diameter of 260 nm. The nanoscale size and mesoporous character impart a fast adsorption rate and high adsorption capacity for iAs. In total, 0.1 mg L‑1 As(V) and As(III) could be adsorbed within 2 min, and the maximum adsorption capacities were 114.8 mg g‑1 for As(V) and 143.6 mg g‑1 for As(III), higher than most previously reported adsorbents. The anti-interference capacity for iAs adsorption was improved by the electrostatic repulsion and size exclusion effects of the MIL-100(Fe) shell, which also decreased the zero-charge point of the hybrid absorbent for a broad pH adsorption range. The adsorption mechanisms of iAs on the MNPs are proposed. An Fe-O-As structure was formed on CoFe2O4@MIL-100(Fe) through hydroxyl substitution with the deprotonated iAs species. Monolayer adsorption of As(V) was observed, while hydrogen bonding led to the multi-layer adsorption of neutral As(III) for its high adsorption capacity. The high efficiency and the excellent pH- and interference-tolerance capacities of CoFe2O4@MIL-100(Fe) allowed effective iAs removal from natural water samples, as validated with batch magnetic separation mode and a portable filtration strategy.

  4. Development of coconut pith chars towards high elemental mercury adsorption performance - Effect of pyrolysis temperatures.

    Science.gov (United States)

    Johari, Khairiraihanna; Saman, Norasikin; Song, Shiow Tien; Cheu, Siew Chin; Kong, Helen; Mat, Hanapi

    2016-08-01

    In this study, chars from coconut pith (CP) were prepared aiming for superior adsorption towards elemental mercury (Hg(o)). The yield, proximate analysis, textural characteristics, surface functional groups and elemental composition analyses of the chars produced at pyrolysis temperature of 300 °C, 500 °C, 700 °C and 900 °C were compared. The surface area, pore volume, ash and carbon content of chars increased, while the yield and moisture content decreased with increasing pyrolysis temperatures. The changing of physical and chemical properties of the chars produced at variety pyrolysis temperature was much effect on the Hg(o) adsorption performance and definitely provides important information on the Hg(o) adsorption mechanism. The highest Hg(o) adsorption capacity was observed for CP900 (6067.49 μg/g), followed by CP700 (2395.98 μg/g), CP500 (289.76 μg/g), CP300 (1.68 μg/g), and CP (0.73 μg/g). The equilibrium data were well described by the Freundlich adsorption isotherm model. The pseudo-second order best described the kinetic data of the Hg(o) adsorption onto CP and CP300. For chars produced at higher pyrolysis temperature, however, the pseudo-zero order and pseudo-second order fitted well for the adsorption and breakthrough regions, respectively. The Hg(o) adsorption capacity of chars obtained from high pyrolysis temperature of CP significantly outperformed the commercial activated carbon (Darco KB-B) as well as superior to chars reported in the literature indicating the CP can be used as a precursor for preparation of chars as elemental mercury adsorbents.

  5. Experiences of High-Ability High School Students: A Case Study

    Science.gov (United States)

    Schmitt, Carrie; Goebel, Vella

    2015-01-01

    This study attempted to answer the question, "To what extent do 12th-grade high-ability students feel that their past educational experiences, particularly in high school, have challenged their academic abilities?" Much research has been conducted in the field of gifted education about the identification, social and emotional…

  6. Novel biosorbent with high adsorption capacity prepared by chemical modification of white pine (Pinus durangensis) sawdust. Adsorption of Pb(II) from aqueous solutions.

    Science.gov (United States)

    Salazar-Rabago, J J; Leyva-Ramos, R

    2016-03-15

    The natural sawdust (NS) from white pine (Pinus durangensis) was chemically modified by a hydrothermal procedure using citric, malonic and tartaric acids. The adsorption capacity of modified sawdust (MS) towards Pb(II) was considerably enhanced due to the introduction of carboxylic groups on the surface of MS during the modification, and the adsorption capacity was almost linearly dependent on the concentration of carboxylic sites. The NS surface was acidic, and the MS surface became more acidic after the modification. At T = 25 °C and pH = 5, the maximum adsorption capacity of the optimal MS towards Pb(II) was 304 mg/g, which is exceptionally high compared to NS and other MS reported previously. The adsorption capacity of MS was considerably reduced from 304 to 154 mg/g by decreasing the solution pH from 5 to 3 due to electrostatic interactions. The adsorption of Pb(II) on MS was reversible at pH = 2, but not at pH = 5. The contribution percentage of ion exchange to the overall adsorption capacity ranged from 70 to 99% and 10-66% at the initial pH of 3 and 5, respectively. Hence, the adsorption of Pb(II) on MS was mainly due to ion exchange at pH = 3 and to both ion exchange and electrostatic attraction at pH = 5.

  7. High-Capacity and Photoregenerable Composite Material for Efficient Adsorption and Degradation of Phenanthrene in Water.

    Science.gov (United States)

    Liu, Wen; Cai, Zhengqing; Zhao, Xiao; Wang, Ting; Li, Fan; Zhao, Dongye

    2016-10-18

    We report a novel composite material, referred to as activated charcoal supported titanate nanotubes (TNTs@AC), for highly efficient adsorption and photodegradation of a representative polycyclic aromatic hydrocarbon (PAH), phenanthrene. TNTs@AC was prepared through a one-step hydrothermal method, and is composed of an activated charcoal core and a shell of carbon-coated titanate nanotubes. TNTs@AC offered a maximum Langmuir adsorption capacity of 12.1 mg/g for phenanthrene (a model PAH), which is ∼11 times higher than the parent activated charcoal. Phenanthrene was rapidly concentrated onto TNTs@AC, and subsequently completely photodegraded under UV light within 2 h. The photoregenerated TNTs@AC can then be reused for another adsorption-photodegradation cycle without significant capacity or activity loss. TNTs@AC performed well over a wide range of pH, ionic strength, and dissolved organic matter. Mechanistically, the enhanced adsorption capacity is attributed to the formation of carbon-coated ink-bottle pores of the titanate nanotubes, which are conducive to capillary condensation; in addition, the modified microcarbon facilitates transfer of excited electrons, thereby inhibiting recombination of the electron-hole pairs, resulting in high photocatalytic activity. The combined high adsorption capacity, photocatalytic activity, and regenerability/reusability merit TNTs@AC a very attractive material for concentrating and degrading a host of micropollutants in the environment.

  8. STRUCTURAL EFFECTS ON THE HIGH TEMPERATURE ADSORPTION OF CO2 ON A SYNTHETIC HYDROTALCITE

    Science.gov (United States)

    Hydrotalcite-like compounds (HTlcs) are solid sorbents that may potentially be used for high temperature separation and capture of CO2. The high-temperature adsorption of CO2 on Mg-Al-CO3 HTlc is affected by structural changes that take place upo...

  9. Preparation and Adsorption Performances of Phragmites australis Activated Carbon with High Acidity

    Directory of Open Access Journals (Sweden)

    FU Cheng-kai

    2017-03-01

    Full Text Available For removal of heavy metals from wastewater and recycling the wetland plants, the present study investigated the viability of using silage of Phragmites australis (PA to prepare activated carbons (ACs with high acidity. BET surface area, porous texture and surface functional characteristics of ACs were analyzed by N2 adsorption/desorption, elemental analysis and Boehm titration method. ACs presented well-developed micro-porosity and favorable surface acidity. The sorption equilibrium data for Ni (Ⅱ and Cd (Ⅱ sorption onto ACs were analyzed by the Langmuir and Freundlich models. The Langmuir model was fitted well to the adsorption behavior. The properties of high surface acidity promoted the adsorption of heavy metals by the silage-treated ACs and the chemical sorption played the key role in the sorption process.

  10. Factors Influencing Academic Self-Concept of High-Ability Girls in Singapore

    Science.gov (United States)

    Yeo, Melissa Mui Mei; Garces-Bacsal, Rhoda Myra

    2014-01-01

    This study aimed at investigating the impact of entering high-ability classes on the academic self-concept of high-ability primary girls in Singapore. Participants in this study are 91 Primary 4 girls, 30 high-ability pupils, and 61 pupils from classes that include high-, middle-, and low-ability pupils. This study utilized a mixed-method…

  11. Myth 15: High-Ability Students Don't Face Problems and Challenges

    Science.gov (United States)

    Moon, Sidney M.

    2009-01-01

    One rationale for failure to address the needs of high-ability students in schools is that high-ability students do not need special services because they do not face any special problems or challenges. A more extreme corollary of this attitude is the notion that high ability is so protective that students with high ability do not face problems or…

  12. Phosphate adsorption on lanthanum loaded biochar.

    Science.gov (United States)

    Wang, Zhanghong; Shen, Dekui; Shen, Fei; Li, Tianyu

    2016-05-01

    To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC.

  13. Study of high-pressure adsorption from supercritical fluids by the potential theory

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Shapiro, Alexander

    2009-01-01

    The multicomponent potential theory of adsorption (MPTA), which has been previously used to study low-pressure adsorption of subcritical fluids, is extended to adsorption equilibria from supercritical fluids up to high pressures. The MPTA describes an adsorbed phase as an inhomogeneous fluid...... with thermodynamic properties that depend on the distance from the solid surface (or position in the porous space). The description involves the two kinds of interactions present in the adsorbed fluid, i.e. the fluid-fluid and fluid-solid interactions. accounted for by means of an equation of state (Eo......S) and interaction potential functions, respectively. This makes it possible to generate the different MPTA models by combination of the relevant EoS/potentials. In the present work, the simplified perturbed-chain statistical associating fluid theory (sPC-SAFT) EoS is used for the thermodynamic description of both...

  14. Mechanism of highly efficient adsorption of 2-chlorophenol onto ultrasonic graphene materials: Comparison and equilibrium.

    Science.gov (United States)

    Soltani, Tayyebeh; Lee, Byeong-Kyu

    2016-11-01

    The deficiencies of the recently reported improved Hummers method for the synthesis of graphene oxide (GO), such as high reaction temperature (60°C) and long reaction time (10h), were successfully solved using a low-intensity ultrasonic bath for 30min at 40°C. Furthermore, compared to its conventional synthesis counterpart, a facile and fast, one-step ultrasonic method that excluded hydrazine hydrate was developed to synthesize reduced GO (rGO) from graphite (10min, 50°C) in the presence of hydrazine hydrate (rGO-C, 12h, 90°C). The adsorption characteristics of 2-chlorophenol (2-CP) from an aqueous solution were investigated using rGOs and GOs prepared by ultrasonic (rGO-Us/GO-Us) and conventional (rGO-C/GO-C) methods. Whereas 2-CP was completely removed with rGO-Us after 50min, only 40% of 2-CP was eliminated with rGO-C. The maximum adsorption capacity of 2-CP calculated by the Langmuir model onto rGO-Us (208.67mg/g) was much higher than that onto GO-Us (134.49mg/g). In addition, the ultrasonic graphene adsorption capacities were much higher than the corresponding values of rGO-C (49.9mg/g) and GO-C (32.06mg/g). The enhanced adsorption for rGO-Us and GO-Us is attributed to their greater surface areas, excellent oxygenated groups for GO-Us and superior π-electron-rich matrix for rGO-Us, compared to other adsorbents. The adsorption of 2-CP on the rGO materials increased with increasing solution pH to a maximum around its pKa (pKa=8.85), while the adsorption for the GO materials increased with decreasing solution pH. The adsorption mechanism proceeded via hydrogen bonding in neutral and acidic media, but via π-π electron donor-accepter (EDA) interactions between 2-CP and graphene materials in basic medium. The FTIR spectrum of GO-Us after adsorption indicates that the position and intensity of many peaks of GO-Us were affected due to the adsorption of different 2-CP groups at different pHs. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Construction of a high efficiency copper adsorption bacterial system via peptide display and its application on copper dye polluted wastewater.

    Science.gov (United States)

    Maruthamuthu, Murali Kannan; Nadarajan, Saravanan Prabhu; Ganesh, Irisappan; Ravikumar, Sambandam; Yun, Hyungdon; Yoo, Ik-Keun; Hong, Soon Ho

    2015-11-01

    For the construction of an efficient copper waste treatment system, a cell surface display strategy was employed. The copper adsorption ability of recombinant bacterial strains displaying three different copper binding peptides were evaluated in LB Luria-Bertani medium (LB), artificial wastewater, and copper phthalocyanine containing textile dye industry wastewater samples. Structural characteristics of the three peptides were also analyzed by similarity-based structure modeling. The best binding peptide was chosen for the construction of a dimeric peptide display and the adsorption ability of the monomeric and dimeric peptide displayed strains were compared. The dimeric peptide displayed strain showed superior copper adsorption in all three tested conditions (LB, artificial wastewater, and textile dye industry wastewater). When the strains were exposed to copper phthalocyanine dye polluted wastewater, the dimeric peptide display [543.27 µmol/g DCW dry cell weight (DCW)] showed higher adsorption of copper when compared with the monomeric strains (243.53 µmol/g DCW).

  16. Granular bamboo-derived activated carbon for high CO(2) adsorption: the dominant role of narrow micropores.

    Science.gov (United States)

    Wei, Haoran; Deng, Shubo; Hu, Bingyin; Chen, Zhenhe; Wang, Bin; Huang, Jun; Yu, Gang

    2012-12-01

    Cost-effective biomass-derived activated carbons with a high CO(2) adsorption capacity are attractive for carbon capture. Bamboo was found to be a suitable precursor for activated carbon preparation through KOH activation. The bamboo size in the range of 10-200 mesh had little effect on CO(2) adsorption, whereas the KOH/C mass ratio and activation temperature had a significant impact on CO(2) adsorption. The bamboo-derived activated carbon had a high adsorption capacity and excellent selectivity for CO(2) , and also the adsorption process was highly reversible. The adsorbed amount of CO(2) on the granular activated carbon was up to 7.0 mmol g(-1) at 273 K and 1 bar, which was higher than almost all carbon materials. The pore characteristics of activated carbons responsible for high CO(2) adsorption were fully investigated. Based on the analysis of narrow micropore size distribution of several activated carbons prepared under different conditions, a more accurate micropore range contributing to CO(2) adsorption was proposed. The volume of micropores in the range of 0.33-0.82 nm had a good linear relationship with CO(2) adsorption at 273 K and 1 bar, and the narrow micropores of about 0.55 nm produced the major contribution, which could be used to evaluate CO(2) adsorption on activated carbons.

  17. Application of a high density adsorbent in expanded bed adsorption ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... The high density of the adsorbent allowed the EBA to be operated at linear velocity as high as 657 cm/h ... through precipitation and even dialyzed before sample ... In EBA process, upward fluidized stationary phase with.

  18. ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES

    Science.gov (United States)

    Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

  19. Simultaneous adsorption of methyl red and methylene blue onto biochar and an equilibrium modeling at high concentration.

    Science.gov (United States)

    Ding, Guanyu; Wang, Buyun; Chen, Lingyu; Zhao, Shuangjiao

    2016-11-01

    Methyl red, methylene blue and biochar were used to investigate simultaneous adsorption of dyes onto low-cost adsorbent at different concentrations combinations. Langmuir mixed model could describe the adsorption well at low concentrations. However, it could not describe the adsorption anymore when concentrations of methyl red and methylene blue were higher than 255 and 300 mg L(-1) respectively with 0.5 g L(-1) biochar loading. A new model on the interaction among adsorbed adsorbates at equilibrium was developed. It could describe the adsorption at high concentrations well. According to the experimental results, interaction among dyes molecules would replace the competition onto adsorbent to be the main factor influencing adsorption when amount of adsorbed adsorbates were higher than those required to form a monolayer on all the adsorbing sites of adsorbent. The model was further verified by adsorption with other solute such as glucose or NaCl in solution.

  20. A successful intervention program for high ability minority students

    Science.gov (United States)

    Coleman, Winson R.

    1989-01-01

    intervention program is the Saturday Academy program for high ability minority students in the Washington, D.C. area. A description of the Saturday Academy is provided with the intent of making it available to personnel who are considering the development of similar projects. The effect of participation in the program on high school graduate rates, college enrollment, and choice of quantitative major is examined.

  1. The effect of food and ice cream on the adsorption capacity of paracetamol to high surface activated charcoal

    DEFF Research Database (Denmark)

    Høgberg, Lotte Christine Groth; Angelo, Helle Riis; Christophersen, Anne Bolette

    2003-01-01

    The effect of added food mixture (as if food was present in the stomach of an intoxicated patient) or 4 different types of ice cream (added as a flavouring and lubricating agent) on the adsorption of paracetamol (acetaminophen) to 2 formulations of activated charcoal was determined in vitro......, and paracetamol were mixed with either food mixture or ice cream followed by one hr incubation. The maximum adsorption capacity of paracetamol to activated charcoal was calculated using Langmuirs adsorption isotherm. Paracetamol concentration was analyzed using high pressure liquid chromatography. In the presence...... of food, the paracetamol adsorption capacity of the 2 activated charcoals was reduced by max. 19% (Pcream was mixed with the charcoal...

  2. High-throughput screening of small-molecule adsorption in MOF-74

    Science.gov (United States)

    Thonhauser, T.; Canepa, P.

    2014-03-01

    Using high-throughput screening coupled with state-of-the-art van der Waals density functional theory, we investigate the adsorption properties of four important molecules, H2, CO2, CH4, and H2O in MOF-74-  with  = Be, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Ru, Rh, Pd, La, W, Os, Ir, and Pt. We show that high-throughput techniques can aid in speeding up the development and refinement of effective materials for hydrogen storage, carbon capture, and gas separation. The exploration of the configurational adsorption space allows us to extract crucial information concerning, for example, the competition of water with CO2 for the adsorption binding sites. We find that only a few noble metals--Rh, Pd, Os, Ir, and Pt--favor the adsorption of CO2 and hence are potential candidates for effective carbon-capture materials. Our findings further reveal significant differences in the binding characteristics of H2, CO2, CH4, and H2O within the MOF structure, indicating that molecular blends can be successfully separated by these nano-porous materials. Supported by DOE DE-FG02-08ER46491.

  3. The preparation of high-adsorption, spherical, hexagonal boron nitride by template method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ning, E-mail: zhangning5832@163.com; Liu, Huan; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Zhou, Yonghui

    2014-11-15

    Highlights: • The high-adsorption, spherical, hexagonal boron nitride powders were prepared. • The influence mechanism of template content on the micro-morphology and adsorption was explored. • At appropriate synthesis temperature, higher adsorption mesoporous spheres h-BN began to form. - Abstract: This research used low-cost boric acid and borax as a source of boron, urea as a nitrogen source, dodecyl-trimethyl ammonium chloride (DTAC) as a template, and thus prepared different micro-morphology hexagonal boron nitride powders under a flowing ammonia atmosphere at different nitriding temperatures. The effects of the template content and nitriding temperature on the micro-morphology of hexagonal boron nitride were studied and the formation mechanism analysed. The influences of the template content and nitriding temperature on adsorption performance were also explored. The results showed that at a nitriding temperature of 675 °C, the micro-morphologies of h-BN powder were orderly, inhomogeneous spherical, uniform spherical, beam, and pie-like with increasing template content. The micro-morphology was inhomogeneous spherical at a DTAC dose of 7.5%. The micro-morphology was uniform spherical at a DTAC dose of 10%. At a DTAC dose of 12%, the micro-morphology was a mixture of beam and pie-like shapes. At a certain template content (DTAC at 10%) and at lower nitriding temperatures (625 °C and 650 °C), spherical shell structures with surface subsidence began to form. The porous spheres would appear at a nitriding temperature of 675 °C, and the ball diameter thus formed was approximately 500–600 nm. The ball diameter was about 600–700 nm when the nitriding temperature was 700 °C. At a nitriding temperature of 725 °C, the ball diameter was between 800 and 1000 nm and sintering necking started to form. When the relative pressure was higher, previously closed pores opened and connected with the outside world: the adsorption then increased significantly. The

  4. Removal of I by adsorption with AgX (Ag-impregnated X Zeolite) from high-radioactive seawater waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eil Hee; Lee, Keun Young; Kim, Kwang Wook; Kim, Hyung Ju; Kim, Ik Soo; Chung, Dong Yong; Moon, Jei Kwon; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-09-15

    This study aimed to the adsorption-removal of high- radioactive iodide (I) contained in the initially generated high-radioactive seawater waste (HSW), with the use of AgX (Ag-impregnated X zeolite). Adsorption of I by AgX (hereafter denoted as AgX-I adsorption) was increased by increasing the Ag-impregnated concentration in AgX, and its concentration was suitable at about 30 wt%. Because of AgCl precipitation by chloride ions contained in seawater waste, the leaching yields of Ag from AgX (Ag-impregnated concentration : about 30-35 wt%) was less than those in distilled water (< 1 mg/L). AgX-I adsorption was above 99% in the initial iodide concentration (Ci) of 0.01-10 mg/L at m/V (ratio of weight of adsorbent to solution volume)=2.5 g/L. This shows that efficient removal of I is possible. AgX-I adsorption was found to be more effective in distilled water than in seawater waste, and the influence of solution temperature was insignificant. Ag-I adsorption was better described by a Freundlich isotherm rather than a Langmuir isotherm. AgX-I adsorption kinetics can be expressed by a pseudo-second order rate equation. The adsorption rate constants (k2) decreased by increasing Ci, and conversely increased by increasing the ratio of m/V and the solution temperature. This time, the activation energy of AgX-I adsorption was about 6.3 kJ/mol. This suggests that AgX-I adsorption is dominated by physical adsorption with weaker bonds. The evaluation of thermodynamic parameters (a negative Gibbs free energy and a positive Enthalpy) indicates that AgX-I adsorption is a spontaneous reaction (forward reaction), and an endothermic reaction indicating that higher temperatures are favored.

  5. Adsorption behavior of pesticide methomyl on activated carbon in a high gravity rotating packed bed reactor.

    Science.gov (United States)

    Chang, Chiung-Fen; Lee, Shu-Chi

    2012-06-01

    High gravity rotating packed bed (HGRPB) reactor possesses the property of high mass transfer rate, which is expected to promote the adsorption rate for the process. In this study, HGRPB has been applied on adsorption removal of methomyl from solution, adopting the adsorbent of activated carbon F400. The influence of operating parameters of HGRPB on mass transfer such as the rotating speed (N(R)), the flow rate of solution (F(L)) and initial concentration of methomyl (C(b0)) were examined. The traditionally internal mass transfer models combined with Freundlich isotherm were used to predict the surface and effective diffusion coefficients. In addition, the results have also been compared with those obtained from the traditional basket stirred batch reactor (BBR). The results showed that the larger values of N(R) and F(L) enhanced the effective intraparticle diffusion and provided more accessible adsorption sites so as to result in lower equilibrium concentration in HGRPB system when compared to SBR system. The results of adsorption kinetics demonstrated that surface and effective diffusions were both significantly greater in HGRPB system instead of BBR system. Furthermore, the values of Bi(S) also manifested less internal mass transfer resistance in HGRPB system. The contribution ratio (R(F)) of the surface to pore diffusion mass transport showed that the larger contribution resulted from the surface diffusion in HGRPB system. Therefore, the results reasonably led to the conclusion that when the HGRPB system applied on the adsorption of methomyl on F400, the lower equilibrium concentration and faster internal mass transfer can be obtained so as to highly possess great potential to match the gradually stricter environmental standard.

  6. Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults

    Science.gov (United States)

    Miller, Angie L.; Lambert, Amber D.; Speirs Neumeister, Kristie L.

    2012-01-01

    The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and…

  7. Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults

    Science.gov (United States)

    Miller, Angie L.; Lambert, Amber D.; Speirs Neumeister, Kristie L.

    2012-01-01

    The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and…

  8. High-resolution adsorption analysis of pillared zeolites IPC-3PI and MCM-36.

    Science.gov (United States)

    Zukal, Arnošt; Kubů, Martin

    2014-07-21

    The porous structure of pillared zeolites IPC-3PI and MCM-36 and their precursors IPC-3P and MCM-22P, respectively, has been investigated by means of a high-resolution adsorption analysis. The analysis was based on argon adsorption isotherms measured at 87 K from the relative pressure of 10(-6). The isotherms were processed by means of the t-plot method, which made it possible to distinguish adsorption in micropores from adsorption in mesopores. The pore size distribution was evaluated from argon isotherms using Non-Local Density Functional Theory. The obtained results have shown that the microporous structure of the MWW layers is preserved in both pillared zeolites. In contrast to precursors IPC-3P and MCM-22P, pillared samples are characterized by the formation of a porous structure belonging to the lower mesopore region. The distribution of mesopores in the zeolite IPC-3PI is broader and is shifted to larger widths in comparison with the zeolite MCM-36.

  9. Adsorption and photocatalytic degradation of methylene blue using high surface area titanate nanotubes (TNT) synthesized via hydrothermal method

    Science.gov (United States)

    Subramaniam, M. N.; Goh, P. S.; Abdullah, N.; Lau, W. J.; Ng, B. C.; Ismail, A. F.

    2017-06-01

    Removal of methylene blue (MB) via adsorption and photocatalysis using titanate nanotubes (TNTs) with different surface areas were investigated and compared to commercial titanium dioxide (TiO2) P25 Degussa nanoparticles. The TNTs with surface area ranging from 20 m2/g to 200 m2/g were synthesized via hydrothermal method with different reaction times. TEM imaging confirmed the tubular structure of TNT while XRD spectra indicated all TNTs exhibited anatase crystallinity. Batch adsorption rate showed linearity with surface properties of TNTs, where materials with higher surface area showed higher adsorption rate. The highest MB adsorption (70%) was achieved by TNT24 in 60 min whereas commercial TiO2 exhibited the lowest adsorption of only 10% after 240 min. Adsorption isotherm studies indicated that adsorption using TNT is better fitted into Langmuir adsorption isotherm than Freundlich isotherm model. Furthermore, TNT24 was able to perform up to 90% removal of MB within 120 min, demonstrating performance that is 2-fold better compared to commercial TiO2. The high surface area and surface Bronsted acidity are the main reasons for the improvement in MB removal performance exhibited by TNT24. The improvement in surface acidity enhanced the adsorption properties of all the nanotubes prepared in this study.

  10. A Valuable Biochar from Poplar Catkins with High Adsorption Capacity for Both Organic Pollutants and Inorganic Heavy Metal Ions.

    Science.gov (United States)

    Liu, Xia; Sun, Ju; Duan, Shengxia; Wang, Yanan; Hayat, Tasawar; Alsaedi, Ahmed; Wang, Chengming; Li, Jiaxing

    2017-08-30

    In this paper, biochar derived from poplar catkins was used as an economical and renewable adsorbent for adsorption organic and inorganic pollutants such as, dyes, organic compounds, and heavy metal ions from wastewater. Mesoporous activated carbonized poplar catkins (ACPCs) were produced from char as a by-product by carbonized poplar catkins (CPCs). With their high surface area, ACPCs exhibited the maximum adsorption capacities of 71.85 and 110.17 mg/g for the removal of inorganic U(VI) and Co(II). Compared other biochars adsorbents, ACPCs can also adsorb organic pollutants with the maximum adsorption capacities of 534, 154, 350, 148 and 384 mg/g for methylene blue (MB), methyl orange (MO), Congo red (CR), chloramphenicol (CAP) and naphthalene. The adsorption of organic pollutants was fitted with pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models figure out the kinetic parameters and adsorption mechanisms. Langmuir adsorption isotherm was found to be suitable for Co(II) and U(VI) adsorption and thermodynamic studies indicated adsorption processes to be endothermic and spontaneous. The adsorption process includes both outer-sphere surface complexes and hydrogen-bonding interactions. The results showed that biochar derived from poplar catkins was a potential material to remove pollutants in wastewater.

  11. High Density Gold Nanoparticles Within Three-Dimensionally Mesoporous SBA-15: Adsorption Behavior and Optical Properties.

    Science.gov (United States)

    Wang, Xiaojuan; Yan, Xiaoqing; Li, Renhong; Xiao, Liping; Ma, Guicen; Dai, Yihu; Fan, Jie

    2015-09-01

    Unprecedentedly high-density (up to 79 wt%) immobilization of monodispersed gold nanoparticles (AuNPs) within mesoporous silica SBA-15 is achieved by variation of their pore size and pore-pore connectivity to enable a full access of AuNPs to the large and high-affinity internal surface of mesoporous silica (MPS) SBA-15. In addition, according to the adsorption kinetics, dipole-induced dipole interaction is suggested to be the primary driving force for adsorption of AuNPs on silica. Interestingly, the high internal surface of MPS shows much higher affinity to AuNPs than the external surface. The optical properties of these densely immobilized AuNPs are also investigated, demonstrating that a plasma coupling exists between closely spaced AuNPs.

  12. High gradient magnetic separation versus expanded bed adsorption: a first principle comparison

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Matthiesen, D.B.; Hobley, Timothy John

    2001-01-01

    A robust new adsorptive separation technique specifically designed for direct product capture from crude bioprocess feedstreams is introduced and compared with the current bench mark technique, expanded bed adsorption. The method employs product adsorption onto sub-micron sized non...

  13. The Possible Selves of High-Ability African Males Attending a Residential High School for Highly Able Youth

    Science.gov (United States)

    Frazier, Andrea Dawn

    2012-01-01

    This study explored the possible selves of high-ability African American males attending a specialized school for high-ability students. To this end, interviews were conducted with nine students. Results provided details about the hoped-for and feared selves the young men envisioned as well as the strategies these youth utilized to realize and…

  14. Adsorption mechanisms and the effect of oxytetracycline on activated sludge.

    Science.gov (United States)

    Song, Xiancai; Liu, Dongfang; Zhang, Guowei; Frigon, Matthew; Meng, Xianrong; Li, Kexun

    2014-01-01

    The adsorption mechanisms and the effect of Oxytetracycline (OTC) onto activated sludge were studied. The results show that the adsorption of Oxytetracycline (OTC) onto activated sludge was coincident with the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model had the best fit which suggested that chemical adsorption mechanism was dominant. The influences including pH and metal ions on the OTC were examined. It was demonstrated that the adsorption process was highly pH-dependant, which indicate that cationic exchange mechanisms may play an important role in the adsorption process. Na(+), K(+), Ca(2+), Mg(2+) and Cd(2+) ions more or less inhibited the adsorption of OTC on activated sludge while Cu(2+) enhanced the adsorption ability. The phenomenon may reflect the result that a surface complexation mechanism could involved in the adsorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Scientific Creativity and High Ability: Gender and academic level differences

    Directory of Open Access Journals (Sweden)

    Fernando Javier ESPARZA MOLINA

    2015-10-01

    Full Text Available  The purpose of this study was to investigate the influence of gender and educational level on scientific creativity among gifted/talented students. A cohort of creatividad científica y alta habilidad: diferencias de género y nivel educativo 78 secondary school students from 12 to 16 years old participated in this research. The scientific creativity was measured using the Creative Scientific Ability Test (Sak & Ayas, 2011 designed for secondary school students from 11 to 14 years old. Its theoretical framework sets up the measurement of a three dimensional structure: general creative abilities (fluency, flexibility and creativity, scientific creative abilities (hypothesis generation, hypothesis testing and evidence evaluation and scientific knowledge. This test has the right adequate psychometric properties with a Cronbach’s alpha coefficient of 0.848 (Sak & Ayas, 2013. Results indicated that male students scored significantly higher in a task named Interaction Graph which measures hypothesis generation in interdisciplinary science. The analysis also showed that students involved in upper education levels scores significantly higher in general fluency and in the task called The Food Chain which measures evidence evaluation in the area of ecology.

  16. High temperature hydrogen sulfide adsorption on activated carbon - I. Effects of gas composition and metal addition

    Science.gov (United States)

    Cal, M.P.; Strickler, B.W.; Lizzio, A.A.

    2000-01-01

    Various types of activated carbon sorbents were evaluated for their ability to remove H2S from a simulated coal gas stream at a temperature of 550 ??C. The ability of activated carbon to remove H2S at elevated temperature was examined as a function of carbon surface chemistry (oxidation, thermal desorption, and metal addition), and gas composition. A sorbent prepared by steam activation, HNO3 oxidation and impregnated with Zn, and tested in a gas stream containing 0.5% H2S, 50% CO2 and 49.5% N2, had the greatest H2S adsorption capacity. Addition of H2, CO, and H2O to the inlet gas stream reduced H2S breakthrough time and H2S adsorption capacity. A Zn impregnated activated carbon, when tested using a simulated coal gas containing 0.5% H2S, 49.5% N2, 13% H2, 8.5% H2O, 21% CO, and 7.5% CO2, had a breakthrough time of 75 min, which was less than 25 percent of the length of breakthrough for screening experiments performed with a simplified gas mixture of 0.5% H2S, 50% CO2, and 49.5% N2.

  17. An Investigation of Cognitive Skills and Behavior in High Ability Students

    Science.gov (United States)

    Alloway, Tracy Packiam; Elsworth, Miquela

    2012-01-01

    The purpose of this study was to investigate the cognitive and behavioral profiles of high ability students. Performance on measures of verbal and visuo-spatial working memory and general ability (vocabulary and block design) was compared across the following groups: high, average, and low ability students. The behavioral profile of high ability…

  18. Porous and Magnetic Molecularly Imprinted Polymers via Pickering High Internal Phase Emulsions Polymerization for Selective Adsorption of λ-Cyhalothrin

    Science.gov (United States)

    Wu, Yunlong; Ma, Yue; Pan, Jianming; Gu, Runxing; Luo, Jialu

    2017-01-01

    A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in ~2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 μmol g−1. Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC.

  19. Polar Ketone-Functionalized Metal-Organic Framework Showing a High CO2 Adsorption Performance.

    Science.gov (United States)

    Feng, Genfeng; Peng, Yuxin; Liu, Wei; Chang, Feifan; Dai, Yafei; Huang, Wei

    2017-03-06

    The incorporation of various functionalities into porous metal-organic frameworks (MOFs) represents an efficacious strategy to improving their gas adsorption properties. In this work, a carbonylated tetracarboxylic acid ligand (5,5'-carbonyldiisophthalic acid) was synthesized, and a ketone-functionalized MOF with exposed metal sites based on this ligand was formed successfully. Structural analysis reveals that the new MOF possesses channels decorated by the carbonyl groups and rhombicuboctahedral cages, with open Cu(II) sites pointing toward the cage center. The framework exhibits exceptionally high CO2 (46.7 wt % at 273 K and 1 bar) and H2 (2.8 wt % at 77 K and 1 bar) uptake. Furthermore, it displays high selectivities of CO2 adsorption over N2 and CH4 at 298 K.

  20. A Novel Cobalt(Ⅲ) Complex with Macrocyclic Triamine Ligand for High Capacity Hydrogen Adsorption

    Institute of Scientific and Technical Information of China (English)

    ZHU Hai-Yan; GUO Hui; LI Sai

    2012-01-01

    The coordination complex of Co(Ⅲ) based on a macrocyclic triamine ligand 1,4-diacetate-1,4,7-triazacyclodecane (L) has been synthesized and characterized. The metal cation is bonded with three nitrogen atoms and two oxygen atoms of L and one chloride ion to form a distorted octahedral geometry. This complex coordinated with macrocyclic ligand possesses large pore volume that will be contributed to observe high H2 adsorption. With respect to the first-principles electronic structure calculations, the feasibility to store hydrogen in the complex is explored. Indeed, the complex has shown a very high total H2 adsorption of 7.2 wt% (wt% = (weight of adsorbed H2)/(weight of host material)), with a binding energy of 0.03 eV/H2

  1. Surface morphology of orthorhombic Mo2C catalyst and high coverage hydrogen adsorption

    Science.gov (United States)

    Wang, Tao; Tian, Xinxin; Yang, Yong; Li, Yong-Wang; Wang, Jianguo; Beller, Matthias; Jiao, Haijun

    2016-09-01

    High coverage hydrogen adsorption on twenty two terminations of orthorhombic Mo2C has been systematically studied by using density functional theory and ab initio thermodynamics. Hydrogen stable coverage on the surfaces highly depends on temperatures and H2 partial pressure. The estimated hydrogen desorption temperatures under ultra-high vacuum condition on Mo2C are in reasonable agreement with the available temperature-programmed desorption data. Obviously, hydrogen adsorption can affect the surface stability and therefore modify the surface morphology of Mo2C. Upon increasing the chemical potential of hydrogen which can be achieved by increasing the H2 partial pressure and/or decreasing the temperature, the proportions of the (001), (010), (011) and (100) surfaces increase, while those of the (101), (110) and (111) surfaces decrease. Among these surfaces, the (100) surface is most sensitive upon hydrogen adsorption and the (111) surface is most exposed under a wide range of conditions. Our study clearly reveals the role of hydrogen on the morphology of orthorhombic Mo2C catalyst in conjugation with hydro-treating activity.

  2. Using Self-Concept Instruments with High-Ability College Students: Reliability and Validity Evidence

    Science.gov (United States)

    Rinn, Anne N.; Cunningham, Lindy G.

    2008-01-01

    This study investigated the reliability and validity of the academic subscales of Marsh's Self-Description Questionnaire III and Neeman and Harter's Self-Perception Profile for College Students for use with high-ability college students. Participants included 100 high-ability college students and 196 average-ability college students enrolled in a…

  3. Adsorption of polar probe molecules on plasma-oxidised high-strength carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Montes-Moran, M.A.; Martinez-Alonso, A.; Tascon, J.M.D. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080, Oviedo (Spain)

    2002-06-20

    The objective of this work was to examine the effect of oxygen plasma treatment on the surface chemistry of carbon fibres. Virgin, unsized high-strength carbon fibres were subjected to oxygen plasma treatments with different degrees of severity. Adsorption of probe molecules with different acid-base characteristics (acetone, carbon tetrachloride, trichloromethane, dichloromethane, diethyl ether, nitromethane, tetrahydrofurane) was measured at 303-353 K using inverse gas chromatography (IGC) at infinite dilution. Plasma treatment brings about increases in the specific free energy of adsorption of either acidic, basic or amphoteric probe molecules, indicating creation of surface functionalities with various acid-base strengths. This helps to justify the improvement in interfacial adhesion in polycarbonate matrix composites following plasma treatment of carbon fibres.

  4. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin

    2014-08-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, bIm and 2-mbIm in DMF solution at 180 °C. Topological analysis indicated that JUC-160 has a zeolite GIS (gismondine) topology. Study of the gas adsorption and thermal and chemical stability of JUC-160 demonstrated its selective adsorption property for carbon dioxide, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvent for up to one week. © 2014 Elsevier B.V.

  5. Adsorption removal of Sr by Barium impregnated 4A Zeolite(BaA) from high radioactive seawater waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eil Hee; Lee, Keun Young; Kim, Kwang Wook; Kim, Ik Soo; Chung, Dong Yong; Moon, Jei Kwon; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-06-15

    This study investigated the removal of Sr, which was one of the high radioactive nuclides, by adsorption with Barium (Ba) impregnated 4A zeolite (BaA) from high-radioactive seawater waste (HSW). Adsorption of Sr by BaA (BaA-Sr), in the impregnated Ba concentration of above 20.2wt%, was decreased by increasing the impregnated Ba concentration, and the impregnated Ba concentration was suitable at 20.2wt%. The BaA-Sr adsorption was added to the co-precipitation of Sr with BaSO4 precipitation in the adsorption of Sr by 4A (4A-Sr) within BaA. Thus, it was possible to remove Sr more than 99% at m/V (adsorbent weight/solution volume)=5 g/L for BaA and m/V >20 g/L for 4A, respectively, in the Sr concentration of less than 0.2 mg/L (actual concentration level of Sr in HSW). It shows that BaA-Sr adsorption is better than 4A-Sr adsorption in for the removal capacity of Sr per unit gram of adsorbent, and the reduction of the secondary solid waste generation (spent adsorbent etc.). Also, BaA-Sr adsorption was more excellent removal capacity of Sr in the seawater waste than distilled water. Therefore, it seems to be effective for the direct removal of Sr from HSW. On the other hand, the adsorption of Cs by BaA (BaA-Cs) was mainly performed by 4A within BaA. Accordingly, it seems to be little effect of impregnated Ba into BaA. Meanwhile, BaA-Sr adsorption kinetics could be expressed the pseudosecond order rate equation. By increasing the initial Sr concentrations and the ratios of V/m, the adsorption rate constants (k2) were decreased, but the equilibrium adsorption capacities (qe) were increasing. However, with increasing the temperature of solution, k2 was conversely increased, and qe was decreased. The activation energy of BaA-Sr adsorption was 38 kJ/mol. Thus, the chemical adsorption seems to be dominant rather than physical adsorption, although it is not a chemisorption with strong bonding form.

  6. Highly Adsorptive, MOF-Functionalized Nonwoven Fiber Mats for Hazardous Gas Capture Enabled by Atomic Layer Deposition

    Science.gov (United States)

    2014-03-20

    areas and high adsorptive capacities. We find that a nanoscale coating of Al2O3 formed by atomic layer deposition (ALD) on the surface of nonwoven ...distribution is unlimited. Highly Adsorptive, MOF-Functionalized Nonwoven Fiber Mats for Hazardous Gas Capture Enabled by Atomic Layer Deposition The... Nonwoven Fiber Mats for Hazardous Gas Capture Enabled by Atomic Layer Deposition Report Title While metal-organic frameworks (MOFs) show great

  7. Synthesis and Characterization of Al-Cr-Pillared Montmorillonite with High Thermal Stability and Adsorption Capacity

    Institute of Scientific and Technical Information of China (English)

    CAO Ming-li; LIU Shi-zhen; YU Yong-fu

    2004-01-01

    Al-Cr-pillared montmorillonite was synthesized by using bentonite and Al-Cr pillaring solutionsas starting materials. The basal spacing and specific surface areas of the materials were significantly increased rela-tive to those of untreated clays. When the Al/Cr molar ratio ( R ) was 0.10, the d (001) value and specific surfacearea of pillared montmorillonite were 1.9194 nm and 165.7 m2 g- 1 , respectively. Thermal stability of the mate-rials was determined using calcined tests and X- ray diffraction (XRD) analysis. The materials formed at differentR(0.05;0.10;0.15;0.25) exhibit a high thermal stability at 300℃ , especially at initial R = 0.10, the basalinterlayer spacing of materials is stabilized at 1.7313 nm after calcined at 500℃ for 2 h. Adsorption behavior ofthe materials was studied by adsorption experiments. The results show that the Al- Cr-pillared montmorillonites ex-hibit much stronger adsorption capacity on Cr6+ in aqueous solution than untreated clays do.

  8. Interfacial adsorption of insulin - Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, SH; Jorgensen, L; Bukrinsky, JT; Elofsson, U; Norde, W; Frokjaer, S

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  9. Interfacial adsorption of insulin. Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, S.H.; Bukrinsky, J.T.; Elofsson, U.; Norde, W.; Frokjaer, S.

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  10. High-throughput screening of small-molecule adsorption in MOF

    OpenAIRE

    Canepa, Pieremanuele; Arter, Calvin A.; Conwill, Eliot M.; Johnson, Daniel H.; Shoemaker, Brian A.; Soliman, Karim Z.; Thonhauser, T.

    2013-01-01

    Using high-throughput screening coupled with state-of-the-art van der Waals density functional theory, we investigate the adsorption properties of four important molecules, H_2, CO_2, CH_4, and H_2O in MOF-74-M with M = Be, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Ru, Rh, Pd, La, W, Os, Ir, and Pt. We show that high-throughput techniques can aid in speeding up the development and refinement of effective materials for hydrogen storage, carbon capture, and gas separation. ...

  11. Clarification of the oxygen adsorption properties of YBaCo_4O_7 at high temperature by thermogravimetry

    Institute of Scientific and Technical Information of China (English)

    朱保峰; 郝好山; 张勇; 贾建峰; 胡行

    2010-01-01

    The oxygen adsorption/desorption properties of YBaCo4O7 at high temperature were investigated by thermogravimetry(TG) method,in which two types of oxygen adsorption were combined.The first type adsorbed oxygen at about 700 °C and released the adsorbed oxygen at 880 °C.After the first type oxygen desorption,even the temperature and oxygen flow were kept the same,a second type oxygen adsorption at about 880 °C occurred and the adsorbed oxygen were released at above 980 °C.The combination of these two types of...

  12. Early Identification of High-Ability Students: Clinical Assessment of Behavior

    Science.gov (United States)

    Bracken, Bruce A.; Brown, Elissa F.

    2008-01-01

    This study investigated the ability of teachers to accurately rate the cognitive and academic functioning of 1,375 students in kindergarten through the third grade on the Clinical Assessment of Behavior (CAB), as compared to two objective cognitive ability tests. CAB teacher ratings were compared for high-ability students who were currently…

  13. Adsorption Behavior of High Stable Zr-Based MOFs for the Removal of Acid Organic Dye from Water

    Directory of Open Access Journals (Sweden)

    Ke-Deng Zhang

    2017-02-01

    Full Text Available Zirconium based metal organic frameworks (Zr-MOFs have become popular in engineering studies due to their high mechanical stability, thermostability and chemical stability. In our work, by using a theoretical kinetic adsorption isotherm, we can exert MOFs to an acid dye adsorption process, experimentally exploring the adsorption of MOFs, their external behavior and internal mechanism. The results indicate their spontaneous and endothermic nature, and the maximum adsorption capacity of this material for acid orange 7 (AO7 could be up to 358 mg·g−1 at 318 K, estimated by the Langmuir isotherm model. This is ascribed to the presence of an open active metal site that significantly intensified the adsorption, by majorly increasing the interaction strength with the adsorbates. Additionally, the enhanced π delocalization and suitable pore size of UiO-66 gave rise to the highest host–guest interaction, which further improves both the adsorption capacity and separation selectivity at low concentrations. Furthermore, the stability of UiO-66 was actually verified for the first time, through comparing the structure of the samples before and after adsorption mainly by Powder X-ray diffraction and thermal gravimetric analysis.

  14. Highly effective adsorption of heavy metal ions from aqueous solutions by macroporous xylan-rich hemicelluloses-based hydrogel.

    Science.gov (United States)

    Peng, Xin-Wen; Zhong, Lin-Xin; Ren, Jun-Li; Sun, Run-Cang

    2012-04-18

    Xylan-rich hemicelluloses-based hydrogel was developed as a novel porous bioadsorbent by graft co-polymerization of acrylic acid (AA) and xylan-rich hemicelluloses for adsorption of heavy metal ions (Pd(2+), Cd(2+), and Zn(2+)) from aqueous solutions. The chemical structure, the interaction between the hydrogel and metal ions, and the porous structure of xylan-rich hemicelluloses-g-AA hydrogel were revealed by Fourier transform infrared spectroscopy and scanning electron microscopy. The effects of AA and cross-linker dosage, pH value, contacting time, and initial concentration of metal ion on the adsorption capacity were studied. The adsorption equilibrium time was about 60 min from the adsorption kinetics study. The maximum adsorption capacities of Pd(2+), Cd(2+), and Zn(2+) were 859, 495, and 274 mg/g, respectively. Furthermore, xylan-rich hemicelluloses-g-AA hydrogel also exhibited highly efficient regeneration and metal ion recovery efficiency and can be reused without noticeable loss of adsorption capacity for Pd(2+), Cd(2+), and Zn(2+) after quite a number of repeated adsorption/desorption cycles.

  15. Heritability of high reading ability and its interaction with parental education.

    Science.gov (United States)

    Friend, Angela; DeFries, John C; Olson, Richard K; Pennington, Bruce; Harlaar, Nicole; Byrne, Brian; Samuelsson, Stefan; Willcutt, Erik G; Wadsworth, Sally J; Corley, Robin; Keenan, Janice M

    2009-07-01

    Moderation of the level of genetic influence on children's high reading ability by environmental influences associated with parental education was explored in two independent samples of identical and fraternal twins from the United States and Great Britain. For both samples, the heritability of high reading performance increased significantly with lower levels of parental education. Thus, resilience (high reading ability despite lower environmental support) is more strongly influenced by genotype than is high reading ability with higher environmental support. This result provides a coherent account when considered alongside results of previous research showing that heritability for low reading ability decreased with lower levels of parental education.

  16. (3) Development of composite adsorbents for high decontamination and their selective adsorption properties

    Science.gov (United States)

    Mimura, Hitoshi; Yamagishi, Isao

    In an action for the convergence of the Fukushima Daiichi Nuclear Power Plant accident, the completion of Step 2 was declared in last December, 2011. As for the circulating cooling system supporting the cold shutdown of nuclear reactor, the temporary treatment equipment operation maintains stability. On the other hand, the establishment of permanent equipments, safety storage, treatment and disposal for the secondary solid wastes are urgent subjects. This special issue deals with the development of highly functional composite adsorbents and the evaluation of selective adsorption properties. The technical issues for the stable treatment and disposal of solid wastes are further discussed.

  17. Ultra-high adsorption capacity of zeolitic imidazole framework-67 (ZIF-67) for removal of malachite green from water.

    Science.gov (United States)

    Lin, Kun-Yi Andrew; Chang, Hsuan-Ang

    2015-11-01

    Zeolitic imidazole frameworks (ZIFs), a new class of adsorbents, are proposed to adsorb Malachite Green (MG) in water. Particularly, ZIF-67 was selected owing to its stability in water and straightforward synthesis. The as-synthesized ZIF-67 was characterized and used to adsorb MG from water. Factors affecting the adsorption capacity were investigated including mixing time, temperature, the presence of salts and pH. The kinetics, adsorption isotherm and thermodynamics of the MG adsorption to ZIF-67 were also studied. The adsorption capacity of ZIF-67 for MG could be as high as 2430mgg(-1) at 20°C, which could be improved at the higher temperatures. Such an ultra-high adsorption capacity of ZIF-67 was almost 10-times of those of conventional adsorbents, including activated carbons and biopolymers. A mechanism for the high adsorption capacity was proposed and possibly attributed to the π-π stacking interaction between MG and ZIF-67. ZIF-67 also could be conveniently regenerated by washing with ethanol and the regeneration efficiency could remain 95% up to 4 cycles of the regeneration. ZIF-67 was also able to remove MG from the aquaculture wastewater, in which MG can be typically found. These features enable ZIF-67 to be one of the most effective and promising adsorbent to remove MG from water.

  18. Analysis on the Factors Affecting English Listening Ability of High School Students

    Institute of Scientific and Technical Information of China (English)

    高小玉

    2012-01-01

    Listening is one of the most difficult skills to acquire. In language learning, listening is an important means to get information. Listening ability directly affects students' absorption of language, mastery of basic language skills and the ability to communicate with English. Only by hearing correctly, can they read smoothly and fluently. Therefore, high school students should improve their listening ability. Stu- dents' listening ability closely relates to the methods and profieiency in listening. Because of lacking of English environment and basic language skills, most high school students are not proficient in English listening. Therefore, this paper focuses on high school students' listening ability. It analyzes the factors that affect high school students' English listening from different aspects and it also comes up with coun- termeasures to improve students' listening ability.

  19. Application of acid-activated Bauxsol for wastewater treatment with high phosphate concentration: Characterization, adsorption optimization, and desorption behaviors.

    Science.gov (United States)

    Ye, Jie; Cong, Xiangna; Zhang, Panyue; Zeng, Guangming; Hoffmann, Erhard; Liu, Yang; Wu, Yan; Zhang, Haibo; Fang, Wei; Hahn, Hermann H

    2016-02-01

    Acid-activated Bauxsol was applied to treat wastewater with high phosphate concentration in a batch adsorption system in this paper. The effect of acid activation on the change of Bauxsol structure was systematically investigated. The mineralogical inhomogeneity and intensity of Bauxsol decreased after acid activation, and FeCl3·2H2O and Al(OH)3 became the dominant phases of acid-activated Bauxsol adsorption. Moreover, the BET surface area and total pore volume of Bauxsol increased after acid activation. Interaction of initial solution pH and adsorption temperature on phosphate adsorption onto acid-activated Bauxsol was investigated by using response surface methodology with central composite design. The maximum phosphate adsorption capacity of 192.94 mg g(-1) was achieved with an initial solution pH of 4.19 and an adsorption temperature of 52.18 °C, which increased by 7.61 times compared with that of Bauxsol (22.40 mg g(-1)), and was higher than other adsorbents. Furthermore, the desorption studies demonstrated that the acid-activated Bauxsol was successfully regenerated with 0.5 mol L(-1) HCl solution. The adsorption capacity and desorption efficiency of acid-activated Bauxsol maintained at 80.48% and 93.02% in the fifth adsorption-desorption cycle, respectively, suggesting that the acid-activated Bauxsol could be repeatedly used in wastewater treatment with high phosphate concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Social Understanding of High-Ability Children in Middle and Late Childhood

    NARCIS (Netherlands)

    Boor-Klip, H.J.; Cillessen, A.H.N.; Hell, J.G. van

    2014-01-01

    Despite its importance in social development, social understanding has hardly been studied in high-ability children. This study explores differences in social understanding between children in high-ability and regular classrooms, specifically theory of mind (ToM) and perception accuracy, as well as

  1. Locus of Control, Academic Self-Concept, and Academic Dishonesty among High Ability College Students

    Science.gov (United States)

    Rinn, Anne N.; Boazman, Janette

    2014-01-01

    The purposes of the current study were to evaluate a measure of academic dishonesty and examine high ability college students' loci of control and its effect on behaviors of academic dishonesty, as moderated by academic self-concept. A total of 357 high ability college students enrolled at two universities in the southwestern United States took…

  2. Extending Sociological Theorising on High Ability: The Significance of Values and Lived Experience

    Science.gov (United States)

    Mazzoli Smith, Laura

    2014-01-01

    Sociological work on high ability is framed by social constructionist theorising and/or takes a social justice approach, and hence particular analytical intellectual traditions are foregrounded. Whilst these approaches have contributed the main critique of essentialist psychological understandings of high ability, they can eclipse normative…

  3. Do High Ability Learners Enjoy Learning Alone "or" in Groups? It Depends....

    Science.gov (United States)

    Kanevsky, Lannie

    2015-01-01

    Pedagogical shifts favouring collaborative learning and findings of recent studies have raised concerns regarding the claim that gifted students prefer to learn alone. The purpose of this study was to further investigate if, when and how high ability learners want to work with or without others. The distributions of 416 high ability students (n =…

  4. Cognitive, Adaptive, and Psychosocial Differences between High Ability Youth with and without Autism Spectrum Disorder

    Science.gov (United States)

    Doobay, Alissa F.; Foley-Nicpon, Megan; Ali, Saba R.; Assouline, Susan G.

    2014-01-01

    Research on Autism Spectrum Disorder (ASD) is thriving; however, scant empirical research has investigated how ASD manifests in high ability youth. Further research is necessary to accurately differentiate high ability students with ASD from those without the disorder, and thus decrease the risk of misdiagnosis. The purpose of the present study is…

  5. Selecting the Right Educational Setting for High-Ability TCKS: A Mother's Perspective

    Science.gov (United States)

    Yamada, Sylvia

    2015-01-01

    Meeting the needs of gifted students is challenging even in traditional contexts and settings. Well-known issues include a limited choice of schools, underrepresentation of certain populations, and, often, the lack of facilities and support for high-ability students. Imagine, then, the further complexities of high-ability Third Culture Kids (TCKs)…

  6. Memory and Cognitive Strategies of High Ability Students in a Rural Secondary School

    Science.gov (United States)

    Ali, Fuziana; Yunus, Melor Md

    2013-01-01

    This study was conducted to examine language learning strategies employed by the high ability students in a rural secondary school. Memory and cognitive strategies employed by the high ability students were the main focus in this study. A survey design was used and data was collected using Oxford's questionnaires. Findings reveal that the high…

  7. Social Understanding of High-Ability Children in Middle and Late Childhood

    Science.gov (United States)

    Boor-Klip, Henrike J.; Cillessen, Antonius H. N.; van Hell, Janet G.

    2014-01-01

    Despite its importance in social development, social understanding has hardly been studied in high-ability children. This study explores differences in social understanding between children in high-ability and regular classrooms, specifically theory of mind (ToM) and perception accuracy, as well as associations between individual characteristics…

  8. Adsorption of gaseous iodine-131 at high temperatures by silver impregnated alumina

    Institute of Scientific and Technical Information of China (English)

    程庆辉; 李泽军; 褚泰伟

    2015-01-01

    To prevent radioactive iodides from releasing into the environment in an accident of a nuclear power plant, silver-impregnated alumina (Ag/Al2O3) was fabricated, and its performance of radioactive iodine adsorption from high-temperature gas was tested. The silver loadings on alumina were obtained by ICP-OES and the texture properties of Ag/Al2O3 were characterized by N2 adsorption-desorption. The Ag/Al2O3 was of reduced specific surface (107.2 m2/g at 650◦C). Crystalline phases of Ag/Al2O3 were confirmed through XRD characterization. After calcination at 650◦C for 2 h, the crystalline phase of Ag/Al2O3 changed. The 131I-removal efficiency of Ag/Al2O3 was tested at 100, 250, 350, 450 and 650◦C, with good decontamination factor values for the radioactive iodine. Silver-impregnated alumina can be applied as adsorbents to remove radioactive iodine at high temperatures in nuclear accident.

  9. Fiber-based adsorbents having high adsorption capacities for recovering dissolved metals and methods thereof

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Christopher J.; Dai, Sheng; Oyola, Yatsandra

    2016-09-06

    A fiber-based adsorbent and a related method of manufacture are provided. The fiber-based adsorbent includes polymer fibers with grafted side chains and an increased surface area per unit weight over known fibers to increase the adsorption of dissolved metals, for example uranium, from aqueous solutions. The polymer fibers include a circular morphology in some embodiments, having a mean diameter of less than 15 microns, optionally less than about 1 micron. In other embodiments, the polymer fibers include a non-circular morphology, optionally defining multiple gear-shaped, winged-shaped or lobe-shaped projections along the length of the polymer fibers. A method for forming the fiber-based adsorbents includes irradiating high surface area polymer fibers, grafting with polymerizable reactive monomers, reacting the grafted fibers with hydroxylamine, and conditioning with an alkaline solution. High surface area fiber-based adsorbents formed according to the present method demonstrated a significantly improved uranium adsorption capacity per unit weight over existing adsorbents.

  10. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    Science.gov (United States)

    Usvyat, Denis

    2015-09-01

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around -3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  11. Fiber-based adsorbents having high adsorption capacities for recovering dissolved metals and methods thereof

    Science.gov (United States)

    Janke, Christopher J; Dai, Sheng; Oyola, Yatsandra

    2014-05-13

    A fiber-based adsorbent and a related method of manufacture are provided. The fiber-based adsorbent includes polymer fibers with grafted side chains and an increased surface area per unit weight over known fibers to increase the adsorption of dissolved metals, for example uranium, from aqueous solutions. The polymer fibers include a circular morphology in some embodiments, having a mean diameter of less than 15 microns, optionally less than about 1 micron. In other embodiments, the polymer fibers include a non-circular morphology, optionally defining multiple gear-shaped, winged-shaped or lobe-shaped projections along the length of the polymer fibers. A method for forming the fiber-based adsorbents includes irradiating high surface area polymer fibers, grafting with polymerizable reactive monomers, reacting the grafted fibers with hydroxylamine, and conditioning with an alkaline solution. High surface area fiber-based adsorbents formed according to the present method demonstrated a significantly improved uranium adsorption capacity per unit weight over existing adsorbents.

  12. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    Energy Technology Data Exchange (ETDEWEB)

    Usvyat, Denis, E-mail: denis.usvyat@chemie.uni-regensburg.de [Institute for Physical and Theoretical Chemistry, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg (Germany)

    2015-09-14

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around −3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  13. High-capacity adsorption of aniline using surface modification of lignocellulose-biomass jute fibers.

    Science.gov (United States)

    Gao, Da-Wen; Hu, Qi; Pan, Hongyu; Jiang, Jiping; Wang, Peng

    2015-10-01

    Pyromellitic dianhydride (PMDA) modified jute fiber (MJF) were prepared with microwave treatment to generate a biosorbent for aniline removal. The characterization of the biosorbent was investigated by SEM, BET and FT-IR analysis to discuss the adsorption mechanism. The studies of various factors influencing the adsorption behavior indicated that the optimum dosage for aniline adsorption was 3g/L, the maximum adsorption capacity was observed at pH 7.0 and the adsorption process is spontaneous and endothermic. The aniline adsorption follows the pseudo second order kinetic model and Langmuir isotherm model. Moreover, the biosorbent could be regenerated through the desorption of aniline by using 0.5M HCl solution, and the adsorption capacity after regeneration is even higher than that of virgin MJF. All these results prove MJF is a promising adsorbent for aniline removal in wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A highly sustainable and versatile granulation method of nanodrugs via their electrostatic adsorption onto chitosan microparticles as the granulation substrates.

    Science.gov (United States)

    Yang, Yue; Hadinoto, Kunn

    2013-08-16

    Nanodrugs play important roles in enhancing the sustainability of pharmaceutical manufacturing via their ability to enhance the bioavailability of poorly soluble drugs, resulting in less drug wastage and less mass/energy consumed in their manufacturing. Despite their sustainability enhancement capability, solid dosage form manufacturing of nanodrugs remains lacking from the sustainability perspective. One example is the granulation of nanodrugs prior to tablet preparation, where existing methods (e.g. wet granulation, spray granulation, spray drying) require high energy and time expenses, or are highly intricate often leading to product inconsistencies. Herein we present an alternative nanodrug granulation method via electrostatic adsorption of the nanodrugs onto chitosan microparticles acting as granulation substrates. The method is sustainable involving only mixing of aqueous suspensions of the nanodrugs and substrates under ambient conditions, followed by washing and drying. We investigate the effects of substrate's physical characteristics and nanodrug to substrate ratio on the nanodrug loading in the granules, content uniformity, nanodrug recovery, and granule flowability. Ciprofloxacin and curcumin nanoplexes prepared by drug-polyelectrolyte complexation are used as the model nanodrugs with neutrally, positively, and negatively charged chitosan microparticles as the substrates. Granules having 25% (w/w) nanodrug loading at 50% (w/w) recovery with good flowability have been successfully prepared. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. SAT predicts GPA better for high ability subjects: Implications for Spearman's Law of Diminishing Returns.

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-04-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman's Law of Diminishing Returns, that a test's predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g.

  16. The water-based synthesis of chemically stable Zr-based MOFs using pyridine-containing ligands and their exceptionally high adsorption capacity for iodine.

    Science.gov (United States)

    Wang, Zhe; Huang, Ying; Yang, Jian; Li, Yongsheng; Zhuang, Qixin; Gu, Jinlou

    2017-06-13

    The primary pollutant, radioactive iodine (I2), has become a worldwide concern due to its serious ill effects of radiotoxicity on human health. Therefore, it is of great significance to develop novel adsorbents for effectively eliminating I2 from nuclear waste. Herein, we reported a Zr-based MOF adsorbent constructed by utilizing pyridine-containing pyridine-dicarboxylic acid (PYDC) as organic ligands (UiO-66-PYDC) as well as active sites for the efficient removal of I2. UiO-66-PYDC MOFs were synthesized by a hydrothermal strategy and featured good chemical and thermal stabilities, endowing them with the ability to work in harsh environments. The abundant and inherent pyridine moieties in the developed adsorbent worked as active adsorption sites to capture I2. The correlation between the most significant parameters such as the contact time, adsorbate concentration, and reusability was optimized, and the interaction mechanism between I2 and UiO-66-PYDC was investigated in detail. As for the current adsorbent, a pseudo-second order rate equation was used to explain the removal kinetics, and the Langmuir model exhibited a better fit to the adsorption isotherm than the Freundlich model. Thanks to the strong affinity of PYDC ligands to I2 and high porosity, the adsorption capacities of UiO-66-PYDC for I2 could reach as high as 1250 mg g(-1), which was much higher than those of many other reported MOFs. Additionally, the UiO-66-PYDC MOFs exhibited excellent renewable adsorption properties, prefiguring their great promise as green adsorbents for I2 removal in nuclear waste management.

  17. High effective adsorption of organic dyes on magnetic cellulose beads entrapping activated carbon.

    Science.gov (United States)

    Luo, Xiaogang; Zhang, Lina

    2009-11-15

    Maghemite (gamma-Fe(2)O(3)) nanoparticles were created with a submerged circulation impinging stream reactor (SCISR) from FeCl(3) x 6H(2)O and FeCl(2).4H(2)O by using precipitation followed by oxidation. Subsequently, by blending cellulose with the Fe(2)O(3) nanoparticles and activated carbon (AC) in 7 wt% NaOH/12 wt% urea aqueous solution pre-cooled to -12 degrees C, millimeter-scale magnetic cellulose beads, coded as MCB-AC, was fabricated via an optimal dropping technology. The cellulose beads containning Fe(2)O(3) nanoparticles exhibited sensitive magnetic response, and their recovery could facilitate by applying a magnetic field. The adsorption and desorption of the organic dyes on MCB-AC were investigated to evaluate the removal of dyes (methyl orange and methylene blue) with different charges from aqueous solution. Their adsorption kinetics experiments were carried out and the data were well fitted by a pseudo-second-order equation. The results revealed that the MCB-AC sorbent could efficiently adsorb the organic dyes from wastewater, and the used sorbents could be recovered completely. Therefore, we developed a highly efficient sorbent, which were prepared by using simple and "green" process, for the applications on the removal of hazardous materials.

  18. High effective adsorption of organic dyes on magnetic cellulose beads entrapping activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Luo Xiaogang [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhang Lina, E-mail: lnzhang@public.wh.hb.cn [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2009-11-15

    Maghemite ({gamma}-Fe{sub 2}O{sub 3}) nanoparticles were created with a submerged circulation impinging stream reactor (SCISR) from FeCl{sub 3}.6H{sub 2}O and FeCl{sub 2}.4H{sub 2}O by using precipitation followed by oxidation. Subsequently, by blending cellulose with the Fe{sub 2}O{sub 3} nanoparticles and activated carbon (AC) in 7 wt% NaOH/12 wt% urea aqueous solution pre-cooled to -12 deg. C, millimeter-scale magnetic cellulose beads, coded as MCB-AC, was fabricated via an optimal dropping technology. The cellulose beads containning Fe{sub 2}O{sub 3} nanoparticles exhibited sensitive magnetic response, and their recovery could facilitate by applying a magnetic field. The adsorption and desorption of the organic dyes on MCB-AC were investigated to evaluate the removal of dyes (methyl orange and methylene blue) with different charges from aqueous solution. Their adsorption kinetics experiments were carried out and the data were well fitted by a pseudo-second-order equation. The results revealed that the MCB-AC sorbent could efficiently adsorb the organic dyes from wastewater, and the used sorbents could be recovered completely. Therefore, we developed a highly efficient sorbent, which were prepared by using simple and 'green' process, for the applications on the removal of hazardous materials.

  19. Synthesis of β-Cyclodextrin-Based Electrospun Nanofiber Membranes for Highly Efficient Adsorption and Separation of Methylene Blue.

    Science.gov (United States)

    Zhao, Rui; Wang, Yong; Li, Xiang; Sun, Bolun; Wang, Ce

    2015-12-09

    Water-insoluble β-cyclodextrin-based fibers were synthesized by electrospinining followed by thermal cross-linking. The fibers were characterized by field-emission scanning electron microscopic (FE-SEM) and Fourier transformed infrared spectrometer (FT-IR). The highly insoluble fraction obtained from different pH values (3-11) indicates successful cross-linking reactions and their usability in aqueous solution. After the cross-linking reaction, the fibers' tensile strength increases significantly and the BET surface area is 19.49 m(2)/g. The cross-linked fibers exhibited high adsorption capacity for cationic dye methylene blue (MB) with good recyclability. The adsorption performance can be fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacity is 826.45 mg/g according to Langmuir fitting. Due to electrostatic repulsion, the fibers show weak adsorption toward negatively charged anionic dye methyl orange (MO). On the basis of the selective adsorption, the fiber membrane can separate the MB/MO mixture solution by dynamic filtration at a high flow rate of 150 mL/min. The fibers can maintain good fibrous morphology and high separation efficiency even after five filtration-regeneration cycles. The obtained results suggested potential applications of β-cyclodextrin-based electrospun fibers in the dye wastewater treatment field.

  20. Modeling high adsorption capacity and kinetics of organic macromolecules on super-powdered activated carbon.

    Science.gov (United States)

    Matsui, Yoshihiko; Ando, Naoya; Yoshida, Tomoaki; Kurotobi, Ryuji; Matsushita, Taku; Ohno, Koichi

    2011-02-01

    The capacity to adsorb natural organic matter (NOM) and polystyrene sulfonates (PSSs) on small particle-size activated carbon (super-powdered activated carbon, SPAC) is higher than that on larger particle-size activated carbon (powdered-activated carbon, PAC). Increased adsorption capacity is likely attributable to the larger external surface area because the NOM and PSS molecules do not completely penetrate the adsorbent particle; they preferentially adsorb near the outer surface of the particle. In this study, we propose a new isotherm equation, the Shell Adsorption Model (SAM), to explain the higher adsorption capacity on smaller adsorbent particles and to describe quantitatively adsorption isotherms of activated carbons of different particle sizes: PAC and SPAC. The SAM was verified with the experimental data of PSS adsorption kinetics as well as equilibrium. SAM successfully characterized PSS adsorption isotherm data for SPACs and PAC simultaneously with the same model parameters. When SAM was incorporated into an adsorption kinetic model, kinetic decay curves for PSSs adsorbing onto activated carbons of different particle sizes could be simultaneously described with a single kinetics parameter value. On the other hand, when SAM was not incorporated into such an adsorption kinetic model and instead isotherms were described by the Freundlich model, the kinetic decay curves were not well described. The success of the SAM further supports the adsorption mechanism of PSSs preferentially adsorbing near the outer surface of activated carbon particles.

  1. Synthesis of highly selective zeolite topology molecular sieve for adsorption of benzene gas

    Science.gov (United States)

    Wei, Lin; Chen, Yunlin; Zhang, Baoping; Zu, Zhinan

    2013-02-01

    Shangdong fly ash (SFA), Fangshan fly ash (FFA) and Heilongjiang fly ash (HFA) were selected as the raw materials to be used for synthesis of highly selective zeolite topology molecular sieve. Twice foaming method was studied in terms of synthetic zeolite. The experimental products were characterized by means of X-ray fluorescence (XRF), scanning electron microscope (SEM), X-ray diffraction (XRD), and automated surface area & pore size analyser. The results indicated that 10 M NaOH was chosen as modification experiment condition to process SFA. Crystallization temperature and time were 140 °C and 8 h, respectively. Zeolite topology molecular sieve was prepared with Si/Al molar ratio of 7.9, and its adsorption ratio of benzene gas was up to 66.51%.

  2. Carbon dioxide and water adsorption on highly epitaxial Delafossite CuFeO2 thin film

    Science.gov (United States)

    Rojas, S.; Joshi, T.; Borisov, P.; Sarabia, M.; Lederman, D.; Cabrera, A. L.

    2015-03-01

    Thermal programmed desorption (TPD) of CO2 and H2O from a 200 nm thick CuFeO2 Delafossite surface was performed in a standard UHV chamber, The CuFeO2 thin film grown using Pulsed Laser Deposition (PLD) over an Al2O3 (0001) substrate with controlled O2 atmosphere resulted with highly epitaxial crystal structure. The adsorption/desorption of CO2 and H2O process was also monitored with X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). Our results revealed that carbon dioxide interacts with CuFeO2 forming Fe carbonates compounds on its surface. Hydroxides were also formed on the surface due to water presence. Using TPD data, Arrhenius plots for CO2 and water desorption were done and activation energy for desorption was obtained. Funds FONDECyT 1130372; Thanks to P. Ferrari.

  3. Modification of free-energy density functional theory approach for prediction of high-pressure mixture adsorption

    Institute of Scientific and Technical Information of China (English)

    LIU ShuYan; YANG XiaoNing; YANG Zhen

    2008-01-01

    A modified non-local free energy density functional theory (NDFT) model, with the consideration of the nonadditivity term of solid-fluid and fluid-fluid interactions and finite pore wall thickness (≈2 layers), was developed to model the confined fluid mixtures in slit pore. This improved NDFT approach, com-bining with the pore size distribution (PSD) analysis of adsorbent material can be applied to predicting the adsorption equilibria of high-pressure gas mixtures on activated carbon. Compared with the con-ventional NDFT method, this new approach partly improves the correlation performance of adsorption equilibrium for pure species and increases the reliability of the PSD analysis. For the mixtures, CH4/N2 and CO2/N2, a relatively improved performance has been observed for the adsorption equilibrium pre-diction of the mixtures under high-pressure conditions, especially for the weakly adsorbed species.

  4. High Adsorption of Sulfamethoxazole by an Amine-Modified Polystyrene-Divinylbenzene Resin and Its Mechanistic Insight.

    Science.gov (United States)

    Ling, Chen; Li, Xiaoyun; Zhang, Zhiyun; Liu, Fuqiang; Deng, Yingqing; Zhang, Xiaopeng; Li, Aimin; He, Lili; Xing, Baoshan

    2016-09-20

    Sulfamethoxazole (SMZ) adsorption by a series of amine-modified polystyrene-divinylbenzene resins (PSA/B/C/D) was investigated. All resins showed a similar pH dependent adsorption of SMZ but their capacities were linearly related with the contents of primary amines (-NH2) rather than secondary amines (-NH-). Mechanisms of SMZ adsorption by PSA (highest -NH2 content) were discussed as an example. Due to comparable pKa, H-bonding interactions of -NH2(0) with SMZ(0) (regular H-bond) and SMZ(-) (negative charge-assisted H-bond, (-)CAHB) successively contributed most adsorption (pH 4-9). At weakly acidic pH, -NH2(0) was partially protonated and electrostatic attraction between -NH3(+) and SMZ(-) occurred concurrently, but could be hindered by increased loading of SMZ(0). Hydrophobic/ π-π interactions were not major mechanisms as phenanthrene and nitrobenzenes had little effect on SMZ adsorption. At alkaline pH, where SMZ(-) and -NH2(0) prevailed, adsorption was accompanied by the stoichiometric (∼1.0) proton exchange with water, leading to OH(-) release and the formation of (-)CAHB [SO2N(-)···H···NH2]. The interaction and SMZ spatial distribution in the resin-phase were further confirmed by FTIR and Raman spectra. SMZ was uniformly adsorbed on external and interior surfaces. SMZ adsorption by PSA had low-interference from other coexistent matter, but high stability after multiple regenerations. The findings will guide new adsorbent designs for selectively removing target organics.

  5. Logical Reasoning Abilities of Junior High School Students in the Province of Cotabato, Philippines

    Directory of Open Access Journals (Sweden)

    Paul John B. Ongcoy

    2016-11-01

    Full Text Available Reasoning abilities of the learners and its development was well-discussed in the world of education. The higher the ability of the person to reason abstractly, the higher the probability that a person will effectively function in the society. Thus, it is the main goal of the K-12 Curriculum of the Department of Education to improve the reasoning abilities and formal reasoning among students in the country. The higher the reasoning ability of a person, the more productive he is. The ability of logical reasoning has an essential function in the academic performance of students and their construction of the concepts. This study aimed to determine the logical reasoning abilities of 150 randomly selected junior high school students. Specifically, this study aimed to determine the logical reasoning abilities namely combinatorial reasoning, controlling variables, correlation reasoning, probabilistic reasoning and proportional reasoning among the grade 10 junior high school students and determine whether there is a significant difference in students’ logical reasoning abilities according to their gender. The respondents answered the Test of Logical Thinking (TOLT. Thirty respondents were interviewed to verify their answers. The findings of the study led to the following conclusions: most students correctly answered problems in probabilistic reasoning and least number of students correctly answered problems in proportional reasoning and combinatorial reasoning and, male and female respondents have equal performances in problems pertaining to combinatorial reasoning, controlling variables, correlational reasoning and probabilistic reasoning but female respondents are better in proportional reasoning than the male respondents.

  6. Adsorptive separation of CO2/CH4/CO gas mixtures at high pressures

    NARCIS (Netherlands)

    Krishna, R.

    2012-01-01

    The major objective of this communication is to compare the performance of three metal-organic frameworks (MOFs): CuBTC, MIL-101, and Zn(bdc)dabco, with that of NaX zeolite for selective adsorption of CO2 from mixtures containing CH4 and CO in a pressure swing adsorption (PSA) unit operating at

  7. Isothermal Adsorption Measurement for the Development of High Performance Solid Sorption Cooling System

    Science.gov (United States)

    Saha, Bidyut Baran; Koyama, Shigeru; Alam, K. C. Amanul; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao; Ng, Kim Choon; Chua, Hui Tong

    Interest in low-grade thermal heat powered solid sorption system using natural refrigerants has been increased. However, the drawbacks of these adsorption systems are their poor performance. The objective of this paper is to improve the performance of thermally powered adsorption cooling system by selecting new adsorbent-refrigerant pairs. Adsorption capacity of adsorbent-refrigerant pair depends on the thermophysical properties (pore size, pore volume and pore diameter) of adsorbent and isothermal characteristics of the adsorbent-refrigerant pair. In this paper, the thermophysical properties of three types of silica gels and three types of pitch based activated carbon fibers are determined from the nitrogen adsorption isotherms. The standard nitrogen gas adsorption/desorption measurements on various adsorbents at liquid nitrogen of temperature 77.4 K were performed. Surface area of each adsorbent was determined by the Brunauer, Emmett and Teller (BET) plot of nitrogen adsorption data. Pore size distribution was measured by the Horvath and Kawazoe (HK) method. Adsorption/desorption isotherm results showed that all three carbon fibers have no hysteresis and had better adsorption capacity in comparison with those of silica gels.

  8. The adsorption of lead(II) ions by dynamic high pressure micro-fluidization treated insoluble soybean dietary fiber.

    Science.gov (United States)

    Wang, Hui; Huang, Tao; Tu, Zong-Cai; Ruan, Chuan-Ying; Lin, Derong

    2016-06-01

    Insoluble dietary fiber from soybean residue (SIDF) was treated with dynamic high-pressure microfluidization (DHPM) and used as adsorbent for Pb(II) ion. The effects of pressure on the Pb(II) adsorption capacity, primary cilia structure and surface topography of SIDF were determined using a gastrointestinal simulated model in vitro. SIDF (at pH 7.0) showed maximum binding capacity (261.42 ± 2.77 μmol/g), which was about 1.13 times higher than that of untreated sample (233.47 ± 1.84 μmol/g), when pressure reached 80 MPa. However, the net adsorption value of SIDF in a simulated small intestine (~ 9 μmol/g) was significantly lower than that in the stomach (~ 48 μmol/g), because of the competitive adsorption of Pb(2+) by pancreatin, cholate and several enzymes in the small intestine. In addition, the adsorption capacity of SIDF exhibited good linear relationship with the physicochemical properties of total negative charges, and the adsorption behavior presumably occurred on the surface area of granules fiber.

  9. Adsorption and Vibration of O Atoms on Fe Low-index and Fe (211) High-index Surfaces

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The 5-parameter Morse potential(5-MP) of the interaction between oxygen atoms and iron surfaces was constructed. The adsorption and diffusion of O atoms on Fe low-index and Fe(211 ) high-index surfaces were investigated by using 5-MP. All the critical characteristics of the system, such as adsorption site, adsorption geometry, binding energy, and eigenvalues for vibration, were calculated. The calculation results show that O atoms are located at the fourfold hollow site of the Fe(100) surface with an eigenvibration at 437 cm-1. These results are in good agreement with the experimental and theoretical results obtained previously. With regard to the adsorption site of O-Fe(110) system, the authors of this study assume that the preferential adsorption state is the H3 site and not the LB site, which is not in agreement with the experimental inferences obtained earlier. However, on the Fe( 111 ) and Fe(211 ) surfaces,O atoms predominantly occupy the quasi-3-fold site.

  10. On Strategies of Improving Junior High School Students' Oral English Ability

    Institute of Scientific and Technical Information of China (English)

    罗茜

    2015-01-01

    With the increasingly frequent international exchanges,English,as an international language,has been attached greater importance.The oral English ability of junior high school students plays an indispensable role in their everyday study and social interaction,and it is the present junior school study that can lay a solid foundation for their future study and life. Therefore,to comprehensively improve their oral English ability is in urgent need and of paramount significance.This paper focuses on analyzing the external and internal factors influencing the cultivation of junior high school students' oral English ability,and put forwards the corresponding cultivating strategies of the oral English ability of junior high school students.

  11. On Strategies of Improving Junior High School Students’ Oral English Ability

    Institute of Scientific and Technical Information of China (English)

    罗茜

    2015-01-01

    With the increasingly frequent international exchanges,English,as an international language,has been attached greater importance.The oral English ability of junior high school students plays an indispensable role in their everyday study and social interaction,and it is the present junior school study that can lay a solid foundation for their future study and life.Therefore,to comprehensively improve their oral English ability is in urgent need and of paramount significance.This paper focuses on analyzing the external and internal factors influencing the cultivation of junior high school students’oral English ability,and put forwards the corresponding cultivating strategies of the oral English ability of junior high school students.

  12. Getting Ahead: Current Secondary and Postsecondary Acceleration Options for High-Ability Students in Indiana

    Science.gov (United States)

    Peters, Scott J.; Mann, Rebecca L.

    2009-01-01

    The International Baccalaureate and concurrent enrollment programs are both options available for high-ability high school students. Their value lies in their potential to provide greater depth and breadth of curriculum than is traditionally possible in public high schools. This study surveyed public school corporations in Indiana to examine the…

  13. Developing Student-Centered Learning Model to Improve High Order Mathematical Thinking Ability

    Science.gov (United States)

    Saragih, Sahat; Napitupulu, Elvis

    2015-01-01

    The purpose of this research was to develop student-centered learning model aiming to improve high order mathematical thinking ability of junior high school students of based on curriculum 2013 in North Sumatera, Indonesia. The special purpose of this research was to analyze and to formulate the purpose of mathematics lesson in high order…

  14. Educational level signals unobserved abilities of people with high functioning autism spectrum disorders.

    Science.gov (United States)

    Yokotani, Kenji

    2010-08-01

    The effect of educational level on employment of people with high functioning autism spectrum disorders (HFASD) was examined. If education augments natural abilities to accomplish tasks in people with HFASD, then those with more education would have comparative advantages in both obtaining and retaining jobs. In contrast, if education did not augment natural abilities and only signaled unobservable abilities, one would expect an advantage only in obtaining a job, but not in retention. 22 people with HFASD replied to questionnaires regarding their history of education and employment. Those with job experience had higher educational levels than those with no job experience, but educational level was not significantly different between groups with and without more than one year of job experience. Educational level seems to be associated with abilities, but probably the unobserved abilities underlie both educational attainment and employment history.

  15. Numerical Study on the Contribution of Convective Mass Transfer Inside High-Porosity Adsorbents in the VOC Adsorption Process

    DEFF Research Database (Denmark)

    Zhang, Ge; He, Wenna; Fang, Lei

    2013-01-01

    and cavity would form, approximately, a consecutive parabola. The convective mass transfer inside the adsorbents would have little impact on the axial VOC transfer but could affect the average adsorption rate significantly at high porosities. The Peclet number Pe which is based on the inlet velocity...

  16. Correlations and adsorption mechanisms of aromatic compounds on a high heat temperature treated bamboo biochar.

    Science.gov (United States)

    Yang, Kun; Yang, Jingjing; Jiang, Yuan; Wu, Wenhao; Lin, Daohui

    2016-03-01

    Adsorption of aromatic compounds, including polycyclic aromatic hydrocarbons, nitrobenzenes, phenols, and anilines, on a bamboo biochar produced at 700 °C (Ba700) was investigated with the mechanism discussion by isotherm fitting using the Polanyi-theory based Dubinin-Ashtakhov (DA) model. Correlations of adsorption capacity (Q(0)) of organic compounds with their molecular sizes and melting points, as well as correlations of adsorption affinity (E) with their solvatochromic parameters (i.e., π* and αm), on the biochar, were developed and indicating that adsorption is captured by the pore filling mechanism and derived from the hydrophobic effects of organic compounds and the forming of π-π electron donor-acceptor (EDA) interactions and hydrogen bonding interactions of organic molecules with surface sites of the biochar. The effects of organic molecular sizes and melting points on adsorption capacity are ascribed to the molecular sieving effect and the packing efficiency of the organic molecules in the biochar pores, respectively. These correlations can be used to quantitatively estimate the adsorption of organic compounds on biochars from their commonly physicochemical properties including solvatochromic parameters, melting points and molecular cross-sectional area. The prediction using these correlations is important for assessing the unknown adsorption behaviors of new organic compounds and also helpful to guide the surface modification of biochars and make targeted selection in the environmental applications of biochars as adsorbents.

  17. Molecular basis for the high CO2 adsorption capacity of chabazite zeolites.

    Science.gov (United States)

    Pham, Trong D; Hudson, Matthew R; Brown, Craig M; Lobo, Raul F

    2014-11-01

    CO2 adsorption in Li-, Na-, K-CHA (Si/Al=6,=12), and silica chabazite zeolites was investigated by powder diffraction. Two CO2 adsorption sites were found in all chabazites with CO2 locating in the 8-membered ring (8MR) pore opening being the dominant site. Electric quadrupole-electric field gradient and dispersion interactions drive CO2 adsorption at the middle of the 8 MRs, while CO2 polarization due to interaction with cation sites controls the secondary CO2 site. In Si-CHA, adsorption is dominated by dispersion interactions with CO2 observed on the pore walls and in 8 MRs. CO2 adsorption complexes on dual cation sites were observed on K-CHA, important for K-CHA-6 samples due to a higher probability of two K(+) cations bridging CO2. Trends in isosteric heats of CO2 adsorption based on cation type and concentration can be correlated with adsorption sites and CO2 quantity. A decrease in the hardness of metal cations results in a decrease in the direct interaction of these cations with CO2.

  18. Mathematical ability of students with Asperger syndrome and high-functioning autism: a review of literature.

    Science.gov (United States)

    Chiang, Hsu-Min; Lin, Yueh-Hsien

    2007-11-01

    This article reviews studies investigating cognitive ability and academic achievement of students with Asperger syndrome (AS) and high-functioning autism (HFA). Particular emphasis is placed on the mathematical ability of people with AS/HFA. A preliminary analysis of empirical data is presented. Findings indicate that: (1) the majority of individuals with AS/HFA have average mathematical ability; (2) the majority of individuals with AS/HFA have a significant but clinically modest math weakness; (3) some individuals with AS/HFA have mathematical giftedness.

  19. Introduction of π-complexation into porous aromatic framework for highly selective adsorption of ethylene over ethane

    KAUST Repository

    Li, Baiyan

    2014-06-18

    In this work, we demonstrate for the first time the introduction of π-complexation into a porous aromatic framework (PAF), affording significant increase in ethylene uptake capacity, as illustrated in the context of Ag(I) ion functionalized PAF-1, PAF-1-SO3Ag. IAST calculations using single-component-isotherm data and an equimolar ethylene/ethane ratio at 296 K reveal that PAF-1-SO3Ag shows exceptionally high ethylene/ethane adsorption selectivity (Sads: 27 to 125), far surpassing benchmark zeolite and any other MOF reported in literature. The formation of π-complexation between ethylene molecules and Ag(I) ions in PAF-1-SO 3Ag has been evidenced by the high isosteric heats of adsorption of C2H4 and also proved by in situ IR spectroscopy studies. Transient breakthrough experiments, supported by simulations, indicate the feasibility of PAF-1-SO3Ag for producing 99.95%+ pure C 2H4 in a Pressure Swing Adsorption operation. Our work herein thus suggests a new perspective to functionalizing PAFs and other types of advanced porous materials for highly selective adsorption of ethylene over ethane. © 2014 American Chemical Society.

  20. High-Ability Students: New Ways to Conceptualize Giftedness and Provide Psychological Services in the Schools

    Science.gov (United States)

    Nicpon, Megan Foley; Pfeiffer, Steven I.

    2011-01-01

    Psychologists working in the schools have an opportunity to affect in new and exciting ways the services they provide to high-ability students. A talent development framework offers a unique lens through which gifted services is conceptualized. The framework moves school psychologists beyond viewing giftedness and high IQ as synonymous to…

  1. The Relationship between Utilization of Computer Games and Spatial Abilities among High School Students

    Science.gov (United States)

    Motamedi, Vahid; Yaghoubi, Razeyah Mohagheghyan

    2015-01-01

    This study aimed at investigating the relationship between computer game use and spatial abilities among high school students. The sample consisted of 300 high school male students selected through multi-stage cluster sampling. Data gathering tools consisted of a researcher made questionnaire (to collect information on computer game usage) and the…

  2. Study the adsorption of sulfates by high cross-linked polystyrene divinylbenzene anion-exchange resin

    Science.gov (United States)

    Fathy, Mahmoud; Moghny, Th. Abdel; Awadallah, Ahmed E.; El-Bellihi, Abdel-Hameed A.-A.

    2017-03-01

    In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

  3. High-temperature adsorption layers based on fluoridated polyimide and diatomite carrier

    Science.gov (United States)

    Yakovleva, E. Yu.; Shundrina, I. K.; Gerasimov, E. Yu.

    2017-09-01

    A way of preparing separation layers by the pyrolysis of fluorinated polyimide obtained from 2,4,6-trimethyl- m-phenylenediamine (2,4,6-TM mPDA) and 2,2-bis(3',4'-dicarboxyphenyl)hexafluoropropane (6FDA) applied onto a diatomite carrier is described. Thermogravimetry, elemental analysis, low-temperature nitrogen adsorption, high-resolution electron microscopy, and gas chromatography are used to study changes in the texture and chromatographic characteristics of these layers. It is found that changes in the structure and the effectivity of separation characteristic of the layers depend on the temperature of pyrolysis, which ranges from 250 to 1100°C. It is established that a layer of separation is formed at 250-350°C, and the order of elution of hydrocarbons is similar to their chromatographic behavior on such stationary phases as OV-101. Layers of amorphous carbon formed on the surfaces of individual particles on a diatomite surface at 500-700°C. These layers ensure highly stable and selective separation of permanent gases and hydrocarbons when they are present together.

  4. High-efficient physical adsorption and detection of formaldehyde using Sc- and Ti-decorated graphdiyne

    Science.gov (United States)

    Chen, Xi; Gao, Pengfei; Guo, Lei; Wen, Yanni; Fang, Dangqi; Gong, Baihua; Zhang, Yang; Zhang, Shengli

    2017-03-01

    In sensitive analysis, the ultimate limit is to achieve reliable detection on trace amount of molecules. In this work, Sc- and Ti-decorated graphdiyne were proposed as promising materials for high-efficient molecular detection. Using density functional theory calculations, we investigated the electronic response of single Sc- and Ti-atom-decorated graphdiyne to HCHO (as a typical air pollutant). Thermodynamic analysis predicted that Sc or Ti adatom could be stabilized on the corner sites of single-layer graphdiyne sheet, with migration barriers high enough to prevent Sc or Ti adatom aggregation. The adsorption of HCHO on Sc- or Ti-decorated graphdiyne was found stronger than on pristine graphene or graphdiyne, which provides a prerequisite for molecular sensing. The electronegativity of HCHO leads to strong electronic attraction from Sc or Ti adatom to HCHO, resulting in a remarkable decrease of carrier density in graphdiyne. On Ti-decorated graphdiyne, the electronic attraction of HCHO appears to be stronger than on Sc-decorated graphdiyne and changes the system from metal to n-doped semiconductor. Quantum transport calculations show a decrease of current caused by the adsorbed HCHO. The results systematically exhibit the electronic response of Sc- or Ti-decorated graphdiyne to HCHO and suggest them as promising materials for molecule detection.

  5. Measurement and modeling of single- and multi-component adsorption equilibria of VOC on high-silica zeolites.

    Science.gov (United States)

    Monneyron, Pierre; Manero, Marie-Helene; Foussard, Jean-Noel

    2003-06-01

    From pure and binary gas adsorption equilibria measurements carried out using a volumetric method for three volatile organic compounds (methyl ethyl ketone, toluene (TOL), and 1,4-dioxane) on two high-silica zeolites, desaluminated faujasite Y (Fau Y) and ZSM-5 (Sil Z), co-adsorption was investigated and modeled. Apart from steric exclusion taking place with TOL-containing mixtures on Sil Z, micropore filling was similar to distillation since the component with the lower volatility adsorbed preferentially. At low coverage, chemisorption on specific sites happened in favor of polar or major compound, whereas at saturation the adsorbent was selective for the minor compound. Second, a quantitative prediction of binary equilibria was performed using the ideal adsorbed solution theory (IAST), examining the influence of pure component adsorption fitting model. The efficiency of correlations when extending AST to real mixture behavior was satisfactory in most cases. For engineering purposes, Fau Y is to be considered as a high-adsorption capacity adsorbent, whose selectivity can be described qualitatively by the distillation analogy and predicted quantitatively with the IAST in case of quasi-ideal mixtures.

  6. High-capacity hydrogen and nitric oxide adsorption and storage in a metal-organic framework.

    Science.gov (United States)

    Xiao, Bo; Wheatley, Paul S; Zhao, Xuebo; Fletcher, Ashleigh J; Fox, Sarah; Rossi, Adriano G; Megson, Ian L; Bordiga, S; Regli, L; Thomas, K Mark; Morris, Russell E

    2007-02-07

    Gas adsorption experiments have been carried out on a copper benzene tricarboxylate metal-organic framework material, HKUST-1. Hydrogen adsorption at 1 and 10 bar (both 77 K) gives an adsorption capacity of 11.16 mmol H2 per g of HKUST-1 (22.7 mg g(-)1, 2.27 wt %) at 1 bar and 18 mmol per g (36.28 mg g(-)1, 3.6 wt %) at 10 bar. Adsorption of D2 at 1 bar (77 K) is between 1.09 (at 1 bar) and 1.20(at recovered on exposure of the resulting complex to water is enough to be biologically active, completely inhibiting platelet aggregation in platelet rich plasma.

  7. Development of 30Cr06A, a high strength cast steel and its welding ability

    Institute of Scientific and Technical Information of China (English)

    GAO You-jin

    2008-01-01

    High performance hydraulic supports have a high requirement in strength, toughness and welding ability of socket ma- terial. Targeting this problem, we analyzed the properties of the high strength socket material 30Cr06, used in high performance hydraulic supports both at home and abroad and developed a new kind of high strength cast steel 30Cr06A, by making use of an orthogonal experiment, which provided the design conditions for its optimal composition. The result shows that the strength and toughness of the newly developed high strength cast steel 30Cr06A is much better than that of 30Cr06. Theoretical calculations, mechanical property tests and hardness distribution tests of welded joints were carried out for a study of the welding ability of the new material, which is proved to be very good. Therefore, this 30Cr06A material has been successfully used in the socket of high performance hydraulic support.

  8. Competitive Protein Adsorption - Multilayer Adsorption and Surface Induced Protein Aggregation

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2009-01-01

    In this study, competitive adsorption of albumin and IgG (immunoglobulin G) from human serum solutions and protein mixtures onto polymer surfaces is studied by means of radioactive labeling. By using two different radiolabels (125I and 131I), albumin and IgG adsorption to polymer surfaces...... is monitored simultaneously and the influence from the presence of other human serum proteins on albumin and IgG adsorption, as well as their mutual influence during adsorption processes, is investigated. Exploring protein adsorption by combining analysis of competitive adsorption from complex solutions...... of high concentration with investigation of single protein adsorption and interdependent adsorption between two specific proteins enables us to map protein adsorption sequences during competitive protein adsorption. Our study shows that proteins can adsorb in a multilayer fashion onto the polymer surfaces...

  9. Ability, Parental Valuation of Education and the High School Dropout Decision

    DEFF Research Database (Denmark)

    Foley, Kelly; Gallipoli, Giovanni; Green, David

    We use a large, rich Canadian micro-level dataset to examine the channels through which family socio-economic status and unobservable characteristics a ect children's decisions to drop out of high school. First, we document the strength of observable socio-economic factors: our data suggest...... that teenage boys with two parents who are themselves high school dropouts have a 16% chance of dropping out, compared to a dropout rate of less than 1% for boys whose parents both have a university degree. We examine the channels through which this socio-economic gradient arises using an extended version....... Second, parental valuation of education has an impact of approximately the same size as cognitive ability e ects for medium and low ability teenagers. A low ability teenager has a probability of dropping out of approximately .03 if his parents place a high value on education but .36 if their education...

  10. [Evidence against the myth of adjustment problems of people with high intellectual abilities].

    Science.gov (United States)

    Borges del Rosal, Africa; Hernández-Jorge, Carmen; Rodríguez-Naveiras, Elena

    2011-08-01

    Personal and social adjustment of high-ability children and adolescents is a very important issue in the specialized literature. The differences found between data for and against appropriate adjustment in gifted children and adolescents could be explained by conceptual or methodological biases. In this work, the relation between adjustment and high abilities are contrasted in a sample of teenagers from the Canary Islands, using a screening procedure based on their scores in intelligence tests. Results show that, although gifted adolescents differ significantly from their peers in the control group in socio-economic variables and academic performance, there are no differences in personal, social and educational adjustment. We conclude that adjustment problems and high ability are independent variables, and there is no evidence to support that gifted individuals have adjustment problems.

  11. Looking at the high ability/giftedness through the lens of curriculum studies

    Directory of Open Access Journals (Sweden)

    Soraia Napoleão Freitas

    2011-12-01

    Full Text Available From diving in the educational field, either in teaching or research in Special Education, this article postulates bring visibility to a curricular discussion strongly marked by the educational practice of learners with high ability/giftedness and having the "lighthouse flag” the inclusion policy school principles, not just theorizing about the elements of the theme. Curriculum is understood as a territory of knowledge and power, so the manufacturing process of the curriculum in the wake of the inclusive hillside – a journey which aims to solidify egalitarian social link - can put up as an potentiating agent of different actions for the education of students with high ability/giftedness, protecting them from moments of discrimination, segregation and personal, family, school and social exclusion. Therefore, this article takes up an invitation to educators to look at the prerogatives of education that hosts students with high ability/giftedness with the lens of curriculum studies.

  12. Experimental study on high-pressure adsorption of hydrogen on activated carbon

    Institute of Scientific and Technical Information of China (English)

    周亚平; 周理

    1996-01-01

    A systematic measurement of H2 adsorption on activated carbon over a wide scope of conditions was completed for the first time using a novel cryostat developed by the present authors. The equilibrium temperatures covered 77-298 K with the space of about 20 K, and the equilibrium pressures increased from 0 to about 7MPa. A set of adsorption/desorption isotherms was obtained by a standard volumetric method. This set of experimental data was fitted to all the well-known models of type-I isotherms, and Dubinin-Astakhov (D-A) equation was found to be the best-fit one On the basis of D-A model one can predict adsorption with relative error of ±4%. A 3-dimensional adsorption surface was also constructed, and the isosteric heat of adsorption was analytically determined. Except in the low pressure area, the calculated values agreed well with the experimental ones. Finally, the troubles encountered in applying D-A equation to supercritical adsorption is discussed.

  13. High functioning individuals with schizophrenia have preserved social perception but not mentalizing abilities.

    Science.gov (United States)

    Karpouzian, Tatiana M; Alden, Eva C; Reilly, James L; Smith, Matthew J

    2016-03-01

    Social perception and mentalizing are fundamental social cognitive abilities that are related to functioning and are impaired in schizophrenia. A novel approach to examine the relationship between social cognition and community functioning is to first functionally categorize individuals with schizophrenia and then evaluate social cognitive performance. We evaluated differences in social perception and mentalizing among controls (CON, n=45), high functioning individuals with schizophrenia (HF-SCZ, n=36), and individuals with low functioning schizophrenia (LF-SCZ, n=24). Analyses revealed that HF-SCZ had preserved social perceptual abilities compared to LF-SCZ. Both schizophrenia groups had impaired mentalizing abilities compared to CON, but did not differ from each other. These results suggest that HF-SCZ and LF-SCZ are characterized by differences in the perceptual aspects of social cognition and encourage future research to evaluate the neural basis underlying this preserved ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Protein adsorption of dialdehyde cellulose-crosslinked chitosan with high amino group contents.

    Science.gov (United States)

    Kim, Ung-Jin; Lee, Yeong Ro; Kang, Tong Ho; Choi, Joon Weon; Kimura, Satoshi; Wada, Masahisa

    2017-05-01

    Crosslinked chitosan was prepared by Schiff base formation between the aldehyde groups of dialdehyde cellulose (DAC) and the amino groups of chitosan and a subsequent reduction. DAC was obtained through periodate oxidation of cellulose and solubilization in hot water at 100°C for 1h. Three grades of DAC-crosslinked chitosan were prepared by adding various amounts DAC. The degrees of crosslinking as determined by amino group content were 3.8, 8.3, and 12.1%, respectively. DAC-crosslinked chitosan showed higher stability in the pH 2-9 range and no cytotoxicity was identified over the course of a 21-day long-term stability test. Also, DAC-crosslinked chitosan showed remarkably high bovine serum albumin (BSA) adsorption capacity at pH 5.5 as a result of the increased amino group content, due to the reaction between DAC and chitosan molecular chains occurring at multiple points even though DAC-crosslinked chitosan showed a lower degree of crosslinking.

  15. High gas storage capacities and stepwise adsorption in a UiO type metal-organic framework incorporating Lewis basic bipyridyl sites.

    Science.gov (United States)

    Li, Liangjun; Tang, Sifu; Wang, Chao; Lv, Xiaoxia; Jiang, Min; Wu, Huaizhi; Zhao, Xuebo

    2014-03-04

    A UiO type MOF with Lewis basic bipyridyl sites was synthesized and structurally characterized. After being activated by Soxhlet-extraction, this MOF exhibits high storage capacities for H2, CH4 and CO2, and shows unusual stepwise adsorption for liquid CO2 and solvents, indicating a sequential filling mechanism on different adsorption sites.

  16. Adsorptive removal of Cr3+ from aqueous solutions using chitosan microfibers immobilized with plant polyphenols as biosorbents with high capacity and selectivity

    Science.gov (United States)

    Zhang, Ting; Wang, Yujia; Kuang, Yiwen; Yang, Ruilin; Ma, Jun; Zhao, Shilin; Liao, Yang; Mao, Hui

    2017-05-01

    A novel biosorbent was facilely prepared by immobilizing bayberry tannin (BT, a typical natural polyphenols) onto chitosan microfiber (CM). The as-prepared CM-BT adsorbent featured to a well-defined microfibrous morphology and highly distributed adsorption sites, which was highly efficient and selective for the adsorptive removal of Cr3+ from aqueous solutions. Based on batch experiments, the adsorption of Cr3+ on CM-BT was pH-dependent, and the optimized adsorption pH was determined to be 5.5. The adsorption capacity of CM-BT to Cr3+ was high up to 20.90 mg/g. The co-existing cations, such as Mg2+, Ca2+, Fe3+ and Cu2+, exhibited no significant influences on the adsorption of Cr3+ on CM-BT. The adsorption kinetics were well fitted by the pseudo-second-order rate model (R2 > 0.99) while the adsorption isotherms were well described by the Langmuir model (R2 > 0.98). Importantly, CM-BT was effective for the continues treatment of low concentration Cr3+ (2.0 mg/L) contaminated wastewater. Before reached the breakthrough point (5% of the initial Cr3+ concentration, 0.1 mg/L), the treated volume was as high as 894 bed volume, manifesting the great potential of CM-BT in practical treatment of Cr3+ contaminated wastewater.

  17. Competitive adsorption and ordered packing of counterions near highly charged surfaces: From mean-field theory to Monte Carlo simulations.

    Science.gov (United States)

    Wen, Jiayi; Zhou, Shenggao; Xu, Zhenli; Li, Bo

    2012-04-01

    Competitive adsorption of counterions of multiple species to charged surfaces is studied by a size-effect-included mean-field theory and Monte Carlo (MC) simulations. The mean-field electrostatic free-energy functional of ionic concentrations, constrained by Poisson's equation, is numerically minimized by an augmented Lagrangian multiplier method. Unrestricted primitive models and canonical ensemble MC simulations with the Metropolis criterion are used to predict the ionic distributions around a charged surface. It is found that, for a low surface charge density, the adsorption of ions with a higher valence is preferable, agreeing with existing studies. For a highly charged surface, both the mean-field theory and the MC simulations demonstrate that the counterions bind tightly around the charged surface, resulting in a stratification of counterions of different species. The competition between mixed entropy and electrostatic energetics leads to a compromise that the ionic species with a higher valence-to-volume ratio has a larger probability to form the first layer of stratification. In particular, the MC simulations confirm the crucial role of ionic valence-to-volume ratios in the competitive adsorption to charged surfaces that had been previously predicted by the mean-field theory. The charge inversion for ionic systems with salt is predicted by the MC simulations but not by the mean-field theory. This work provides a better understanding of competitive adsorption of counterions to charged surfaces and calls for further studies on the ionic size effect with application to large-scale biomolecular modeling.

  18. Synthesis and Electrospraying of Nanoscale MOF (Metal Organic Framework) for High-Performance CO2 Adsorption Membrane

    Science.gov (United States)

    Wahiduzzaman; Allmond, Kelsey; Stone, John; Harp, Spencer; Mujibur, Khan

    2017-01-01

    We report the sonochemical synthesis of MOF (metal organic framework) nanoparticles of 30-200 nm in size and electrospraying of those particles on electrospun nanofibers to process a MOF-attached nanofibrous membrane. This membrane displayed significant selectivity towards CO2 and capacity of adsorbing with 4000-5000 ppm difference from a mixed gas flow of 1% CO2 and 99% N2. Applying ultrasonic waves during the MOF synthesis offered rapid dispersion and formation of crystalline MOF nanoparticles in room temperature. The MOF nanoparticles of 100-200 nm in size displayed higher surface area and adsorption capacity comparing to that of 30-60 nm in size. Nanofibrous membrane was produced by electrospinning of MOF blended PAN solution followed by electrospraying of additional MOF nanoparticles. This yielded uniform MOF deposition on nanofibers, occurred due to electrostatic attraction between highly charged nanoparticles and conductive nanofibers. A test bench for real-time CO2 adsorption at room temperature was built with non-dispersive Infrared (NDIR) CO2 sensors. Comparative tests were performed on the membrane to investigate its enhanced adsorption capacity. Three layers of the as-produced membranes displayed CO2 adsorption for approximately 2 h. Thermogravimetric analysis (TGA) of the membrane showed the thermal stability of the MOF and PAN up to 290 and 425 °C, respectively.

  19. Highly Efficient Adsorption of Aqueous Pb(II with Mesoporous Metal-Organic Framework-5: An Equilibrium and Kinetic Study

    Directory of Open Access Journals (Sweden)

    José María Rivera

    2016-01-01

    Full Text Available Mesoporous metal-organic framework-5 (MOF-5, with the composition Zn4O(BDC3, showed a high capacity for the adsorptive removal of Pb(II from 100% aqueous media. After the adsorption process, changes in both morphology and composition were detected using a scanning electron microscope (SEM equipped with an energy dispersive X-ray (EDX system, Fourier transform infrared spectroscopy (FTIR, and X-ray photoelectron spectroscopy (XPS analysis. The experimental evidence showed that Zn(II liberation from MOF-5 structure was provoked by the water effect demonstrating that Pb(II removal is not due to ionic exchange with Zn. A kinetic study showed that Pb(II removal was carried out in 30 min with a behavior of pseudo-second-order kinetic model. The experimental data on Pb(II adsorption were adequately fit by both the Langmuir and BET isotherm models with maximum adsorption capacities of 658.5 and 412.7 mg/g, respectively, at pH 5 and 45°C. The results of this work demonstrate that the use of MOF-5 has great potential for applications in environmental protection, especially regarding the removal of the lead present in industrial wastewaters and tap waters.

  20. High ionic strength narrows the population of sites participating in protein ion-exchange adsorption: a single-molecule study.

    Science.gov (United States)

    Kisley, Lydia; Chen, Jixin; Mansur, Andrea P; Dominguez-Medina, Sergio; Kulla, Eliona; Kang, Marci K; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Dhamane, Sagar; Willson, Richard C; Landes, Christy F

    2014-05-23

    The retention and elution of proteins in ion-exchange chromatography is routinely controlled by adjusting the mobile phase salt concentration. It has repeatedly been observed, as judged from adsorption isotherms, that the apparent heterogeneity of adsorption is lower at more-eluting, higher ionic strength. Here, we present an investigation into the mechanism of this phenomenon using a single-molecule, super-resolution imaging technique called motion-blur Points Accumulation for Imaging in Nanoscale Topography (mbPAINT). We observed that the number of functional adsorption sites was smaller at high ionic strength and that these sites had reduced desorption kinetic heterogeneity, and thus narrower predicted elution profiles, for the anion-exchange adsorption of α-lactalbumin on an agarose-supported, clustered-charge ligand stationary phase. Explanations for the narrowing of the functional population such as inter-protein interactions and protein or support structural changes were investigated through kinetic analysis, circular dichroism spectroscopy, and microscopy of agarose microbeads, respectively. The results suggest the reduction of heterogeneity is due to both electrostatic screening between the protein and ligand and tuning the steric availability within the agarose support. Overall, we have shown that single molecule spectroscopy can aid in understanding the influence of ionic strength on the population of functional adsorbent sites participating in the ion-exchange chromatographic separation of proteins.

  1. Neptunium (V) Adsorption to a Halophilic Bacterium Under High Ionic Strength Conditions: A Surface Complexation Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Ams, David A [Los Alamos National Laboratory

    2012-06-11

    Rationale for experimental design: Np(V) -- important as analog for Pu(V) and for HLW scenarios; High ionic strength -- relevant to salt-based repositories such as the WIPP; Halophilic microorganisms -- representative of high ionic strength environments. For the first time showed: Significant adsorbant to halophilic microorganisms over entire pH range under high ionic strength conditions; Strong influence of ionic strength with increasing adsorption with increasing ionic strength (in contrast to trends of previous low ionic strength studies); Effect of aqueous Np(V) and bacterial surface site speciation on adsorption; and Developed thermodynamic models that can be incorporated into geochemical speciation models to aid in the prediction of the fate and transport of Np(V) in more complex systems.

  2. Amine-containing film deposited in pulsed dielectric barrier discharge at a high pressure and its cell adsorption behaviours

    Institute of Scientific and Technical Information of China (English)

    Hu Wen-Juan; Xie Fen-Yan; Chen Qiang; Weng Jing

    2009-01-01

    With monomer allylamine, amine-containing functional films were prepared in alternative current pulsed dielectric barrier discharge (DBD) at a high pressure. This paper analyses in detail the film properties and structures, such as hydrophilicity, compounds and microstructures as well as amine density by the water contact angle, Fourier transform infrared spectroscopy, atomic force microscopy, and ultraviolet-visible measurement. The influence of discharge param-eters, in particular applied power, on amine density was investigated. As an application the cell adsorption behaviours on plasma polymerization films was performed in-vitro. The results show that at a high pressure pulsed DBD plasma can polymerize films with sufficient amine group on surface, through which the very efficient cell adsorption behaviours was demonstrated, and the high rate of cell proliferation was visualized.

  3. Simulation of type selection for 6-high cold tandem mill based on shape control ability

    Institute of Scientific and Technical Information of China (English)

    PENG Yan; LIU Hong-min; WANG Dong-cheng

    2007-01-01

    A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip's cross section (crown) to express the shape control ability of rolling mill. With the mathematical models and simulation software that were developed by the authors' own models, four types of mills were aimed, including HCM (6-high middle rolls shift type HC (high crown) -mill), HCMW (6-high middle rolls and work rolls shift type HC-mill), UCM (6-high middle rolls shift type HC-mill with middle roll bender) and UCMW (6-high middle rolls and work rolls shift type HC-mill with middle roll bender), and the shape and crown control ability of every mill type was analyzed and compared. An appropriate arrangement mode of tandem mill was brought forward. The results show that UCMW mill is a perfect choice for controlling shape and crown, and the area of control characteristics curve of UCMW (or UCM) is twice than that of HCM, but UCM mill is also a good choice for its simple frame. In other word, the shape and crown controlling ability of UCMW mill is better than that of UCM mill, but the frame of UCM mill is simpler than that of UCMW mill. As for the final type of mill, should be synthetically decided by thinking over fund and equipment technology.

  4. Spatial and numerical processing in children with high and low visuospatial abilities.

    Science.gov (United States)

    Crollen, Virginie; Noël, Marie-Pascale

    2015-04-01

    In the literature on numerical cognition, a strong association between numbers and space has been repeatedly demonstrated. However, only a few recent studies have been devoted to examine the consequences of low visuospatial abilities on calculation processing. In this study, we wanted to investigate whether visuospatial weakness may affect pure spatial processing as well as basic numerical reasoning. To do so, the performances of children with high and low visuospatial abilities were directly compared on different spatial tasks (the line bisection and Simon tasks) and numerical tasks (the number bisection, number-to-position, and numerical comparison tasks). Children from the low visuospatial group presented the classic Simon and SNARC (spatial numerical association of response codes) effects but showed larger deviation errors as compared with the high visuospatial group. Our results, therefore, demonstrated that low visuospatial abilities did not change the nature of the mental number line but rather led to a decrease in its accuracy.

  5. High-demand jobs: age-related diversity in work ability?

    Science.gov (United States)

    Sluiter, Judith K

    2006-07-01

    High-demand jobs include 'specific' job demands that are not preventable with state of the art ergonomics knowledge and may overburden the bodily capacities, safety or health of workers. An interesting question is whether the age of the worker is an important factor in explanations of diversity in work ability in the context of high-demand jobs. In this paper, the work ability of ageing workers is addressed according to aspects of diversity in specific job demands and the research methods that are needed to shed light upon the relevant associated questions. From the international literature, a body of evidence was elicited concerning rates of chronological ageing in distinct bodily systems and functions. Intra-age-cohort differences in capacities and work ability, however, require (not yet existing) valid estimates of functional age or biological age indices for the specific populations of workers in high-demand jobs. Many studies have drawn on the highly demanding work of fire-fighters, ambulance workers, police officers, medical specialists, pilots/astronauts and submarine officers. Specific job demands in these jobs can be physical, mental or psychosocial in origin but may cause combined task-level loadings. Therefore, the assessment of single demands probably will not reveal enough relevant information about work ability in high-demand jobs and there will be a call for more integrated measures. Existing studies have used a variety of methodologies to address parts of the issue: task analyses for quantifying physical work demands, observations of psychological and physiological parameters, measures of psychosocial work demands and health complaints. Specific details about the work ability of ageing workers in high-demand jobs are scarce. In general, specific demands are more likely to overtax the capacities of older workers than those of younger workers in high-demand jobs, implying greater repercussions for health, although these effects also vary considerably

  6. Factors Influencing High School Students' Science Enrollments Patterns: Academic Abilities, Parental Influences, and Attitudes toward Science.

    Science.gov (United States)

    Khoury, Ghada A.; Voss, Burton E.

    This study was designed, using a path analytic model, to assess the relative impact of different factors on science concentration decisions made by grade 10 high school students (N=237). Included in the model were selected demographic and socioeconomic factors, academic abilities factors (including logical thinking), indicators of home and school…

  7. A Comparison of High School Student Interests across Three Grade and Ability Levels.

    Science.gov (United States)

    Gill, Newell T.

    1980-01-01

    Students (Grades 9-11) in two Florida metropolitan high schools rated their interest in 28 topics, such as travel, popular music, religion, the opposite sex, war, and politics. Interests were analyzed by sex, grade, and ability track in English (Honors, Average, Basic). Findings, especially those on romantic interests, are discussed. (SJL)

  8. The Relationship between Critical Thinking Abilities and Classroom Management Skills of High School Teachers

    Science.gov (United States)

    Demirdag, Seyithan

    2015-01-01

    High school teachers experience difficulties while providing effective teaching approaches in their classrooms. Some of the difficulties are associated with the lack of classroom management skills and critical thinking abilities. This quantitative study includes non-random selection of the participants and aims to examine critical thinking…

  9. Pragmatic Inference Abilities in Individuals with Asperger Syndrome or High-Functioning Autism. A Review

    Science.gov (United States)

    Loukusa, Soile; Moilanen, Irma

    2009-01-01

    This review summarizes studies involving pragmatic language comprehension and inference abilities in individuals with Asperger syndrome or high-functioning autism. Systematic searches of three electronic databases, selected journals, and reference lists identified 20 studies meeting the inclusion criteria. These studies were evaluated in terms of:…

  10. Profile of Secondary School Students with High Mathematics Ability in Solving Shape and Space Problem

    Science.gov (United States)

    Putra, Mulia; Novita, Rita

    2015-01-01

    This study aimed to describe the profile of secondary school students with high mathematics ability in solving shape and space problem in PISA (Program for International Student Assessment). It is a descriptive research with a qualitative approach, in which the subjects in this study were students of class VIII SMP N 1 Banda Aceh. The results show…

  11. The Relationship between Critical Thinking Abilities and Classroom Management Skills of High School Teachers

    Science.gov (United States)

    Demirdag, Seyithan

    2015-01-01

    High school teachers experience difficulties while providing effective teaching approaches in their classrooms. Some of the difficulties are associated with the lack of classroom management skills and critical thinking abilities. This quantitative study includes non-random selection of the participants and aims to examine critical thinking…

  12. A Comparison of High School Student Interests across Three Grade and Ability Levels.

    Science.gov (United States)

    Gill, Newell T.

    1980-01-01

    Students (Grades 9-11) in two Florida metropolitan high schools rated their interest in 28 topics, such as travel, popular music, religion, the opposite sex, war, and politics. Interests were analyzed by sex, grade, and ability track in English (Honors, Average, Basic). Findings, especially those on romantic interests, are discussed. (SJL)

  13. Associations between Conceptual Reasoning, Problem Solving, and Adaptive Ability in High-Functioning Autism

    Science.gov (United States)

    Williams, Diane L.; Mazefsky, Carla A.; Walker, Jon D.; Minshew, Nancy J.; Goldstein, Gerald

    2014-01-01

    Abstract thinking is generally highly correlated with problem-solving ability which is predictive of better adaptive functioning. Measures of conceptual reasoning, an ecologically-valid laboratory measure of problem-solving, and a report measure of adaptive functioning in the natural environment, were administered to children and adults with and…

  14. The Effects of Acceleration on High-Ability Learners: A Meta-Analysis

    Science.gov (United States)

    Steenbergen-Hu, Saiying; Moon, Sidney M.

    2011-01-01

    Current empirical research about the effects of acceleration on high-ability learners' academic achievement and social-emotional development were synthesized using meta-analytic techniques. A total of 38 primary studies conducted between 1984 and 2008 were included. The results were broken down by developmental level (P-12 and postsecondary) and…

  15. Accelerated Mathematics and High-Ability Students' Math Achievement in Grades Three and Four

    Science.gov (United States)

    Stanley, Ashley M.

    2011-01-01

    The purpose of this study was to explore the relationship between the use of a computer-managed integrated learning system entitled Accelerated Math (AM) as a supplement to traditional mathematics instruction on achievement as measured by TerraNova achievement tests of third and fourth grade high-ability students. Gender, socioeconomic status, and…

  16. A Phenomenological Exploration of Teacher Training Regarding Academically Advanced/High-Ability Students

    Science.gov (United States)

    Sueker, Carrie Olstad

    2011-01-01

    The needs of academically advanced/high-ability students may not be met in today's schools. When educational needs are not met, students may not reach full potential, may lose intrinsic motivation for learning, and may develop poor work and study habits. The rural school district involved in this study lacks a formal gifted and talented program.…

  17. Creating an Effective and Meaningful Learning Environment for High-Ability Learners!

    Science.gov (United States)

    Davis, Joy Lawson

    2013-01-01

    An effective and meaningful classroom for high-ability students is one in which teaching and learning is focused on meeting students' intellectual, academic, and psychosocial needs using specific strategies to impact their learning today as they prepare for tomorrow. As parents become more engaged with teachers, it also is important for them…

  18. Content-Based Curriculum for High-Ability Learners, Second Edition

    Science.gov (United States)

    VanTassel-Baska, Joyce, Ed.; Little, Catherine A., Ed.

    2011-01-01

    The newly updated "Content-Based Curriculum for High-Ability Learners" provides a solid introduction to curriculum development in gifted and talented education. Written by experts in the field of gifted education, this text uses cutting-edge design techniques and aligns the core content with national and state standards. In addition to a revision…

  19. Patterns of Play Behaviors and Learning Center Choices between High Ability and Typical Children

    Science.gov (United States)

    Wilson, Hope E.

    2015-01-01

    There is a dearth of research regarding young children with high intellectual abilities, particularly research involving the direct observation of children in naturalistic settings. The current study examines 2 years of observations of young children (aged 37-71 months; n = 34) at an early childhood facility. The children were observed during the…

  20. The Impact of Active Visualisation of High School Students on the Ability to Memorise Verbal Definitions

    Science.gov (United States)

    Šmajdek, Anamarija; Selan, Jurij

    2016-01-01

    The era of visual communication influences the cognitive strategies of the individual. Education, too, must adjust to these changes, which raises questions regarding the use of visualisation in teaching. In the present study, we examine the impact of visualisation on the ability of high school students to memorise text. In the theoretical part of…

  1. Perfectionism in High-Ability Students: Relational Precursors and Influences on Achievement Motivation

    Science.gov (United States)

    Speirs Neumeister, Kristie L.; Finch, Holmes

    2006-01-01

    The purpose of the present study was to create and test a model that (a) illustrated variables influencing the development of perfectionism, and (b) demonstrated how different types of perfectionism may influence the achievement goals of high-ability students. Using a multiple groups path analysis, the researchers found that parenting style was…

  2. Neuroscientific Investigator of High Mathematical Ability: An Interview with Michael W. O'Boyle

    Science.gov (United States)

    Kalbfleisch, M. Layne

    2008-01-01

    This article presents an interview with Michael W. O'Boyle, a neuroscientific investigator of high mathematical ability. O'Boyle is a professor in the Department of Human Development and Family Studies, Texas Tech University, and Adjunct Professor of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center.…

  3. The Benefits of Exploring Opera for the Social and Emotional Development of High-Ability Students.

    Science.gov (United States)

    Berman, Kristin B.

    2003-01-01

    This article discusses how the exploration of opera with high-ability students can contribute to positive social and emotional development, particularly the development of humane intelligence, by stimulating ethical and moral awareness, making connections with age-old truths of humanity, and providing a powerful genre for self-expression. Teaching…

  4. Occupational/Career Decision-Making Thought Processes of Adolescents of High Intellectual Ability

    Science.gov (United States)

    Jung, Jae Yup

    2017-01-01

    Three competing models of the career decision-making thought processes of adolescents of high intellectual ability were tested in this study. Survey data were collected from 664 intellectually gifted Australian adolescents and analyzed using structural equation modeling procedures. The finally accepted, optimal model suggested that, regardless of…

  5. Against the Odds: Academic Resilience among High-Ability African American Adolescents Living in Rural Poverty

    Science.gov (United States)

    Ellis, Wendy Taylor

    2010-01-01

    This qualitative study investigated the internal and external protective factors that serve to ameliorate barriers to academic achievement posed by the cultural factors of poverty, minority status, and rural residence for high-ability students, rendering them academically resilient. While there has been ample research on underachievement among…

  6. Studies of protein adsorption on implant materials in relation to biofilm formation I. Activity of Pseudomonas aeruginosa on Polypropylene and High density Polyethylene in presence of serum albumin

    CERN Document Server

    Sinha, S Dutta; Maity, P K; Tarafdar, S; Moulik, S P

    2014-01-01

    The surface of biomaterials used as implants are highly susceptible to bacterial colonization and subsequent infection. The amount of protein adsorption on biomaterials, among other factors, can affect the nature and quality of biofilms formed on them. The variation in the adsorption time of the protein on the biomaterial surface produces a phenotypic change in the bacteria by alteration of the production of EPS (exoplysaccharide) matrix. Knowledge of the effects of protein adsorption on implant infection will be very useful in understanding the chemistry of the biomaterial surfaces, which can deter the formation of biofilms. It is observed that the adsorption of BSA on the biomaterial surfaces increases with time and concentration, irrespective of their type and the nature of the EPS matrix of the bacterial biofilm is dependent on the amount of protein adsorbed on the biomaterial surface. The adsorption of protein (BSA) on the biomaterials, polypropylene (PP) and high density polyethylene (HDPE) has been stu...

  7. Detection of high ability children by teachers and parents: Psychometric quality of new rating checklists for the assessment of intellectual, creative and social ability

    Directory of Open Access Journals (Sweden)

    ULRIKE SOMMER

    2008-06-01

    Full Text Available In the present study we devised scales for teachers’ and parents’ estimation of intellectual, creative and social abilities of fourth grade elementary school pupils. Their scores were related to psychometrically determined ability scores. Ninety-three school pupils in the age range between 9.3 and 11.2 years, as well as their parents and teachers took part. The new rating checklists proved as sufficiently reliable (particularly the teachers’ version. Analyses of validity showed a high correspondence in parents’ and teachers’ estimations of cognitive intelligence, but much lower correspondence for creativity and social ability. Correlating teachers’ and parents’ estimates with the respective psychometric tests shows that teachers and parents were better at identifying intellectual (highability than detecting creative and social abilities. With the exception of social (highability, where girls were usually regarded as highly socially gifted by their parents, there were no differences in parents’ and teachers’ estimations of boys and girls.

  8. A Survey on Students’Oral English Ability in High School

    Institute of Scientific and Technical Information of China (English)

    朱旭

    2013-01-01

    Oral communicative ability is of great importance to measure students’English ability. However, it long exists that English course of high schools focuses on grammar. In economically backward cities where high schools don ’t treat speaking as a necessity, there is a prevailing phenomenon of high marks but dumb English. Based on the fact above, the author adopts some methods to conduct an investigation among teachers and students in a high school in Shanxi province. After an elaborate collec-tion of data and a comprehensive conclusion of information related to students, the author points out problems existing in stu-dents’oral communication in the Grade Two; by analysis, the author points out some possible reasons for these problems; and lastly, the author puts forward some suggestions to these problems accordingly.

  9. An Action Research on How to Improve English Reading Abilities of Students in High School

    Institute of Scientific and Technical Information of China (English)

    王文韬; 于月清; 程雯

    2014-01-01

    This dissertation is based on the characteristics of high school students' reading ability and the latest tendency of curriculum reforms of nation to carry out my action research. Firstly, propose a hypothetical analysis and utilize questionnaire, interviewing, teacher log and student log to collect and analyze information with the aim of verifying the hypothesis. Secondly, Work out an effective action research scheme and carry it out. In the process of carrying out the scheme, I reflect and ameliorate my scheme constantly in order to maximize students' reading ability and raise students' speed. This dissertation is divided into six parts.

  10. Hydrogen adsorption in a highly stable porous rare-earth metal-organic framework: sorption properties and neutron diffraction studies.

    Science.gov (United States)

    Luo, Junhua; Xu, Hongwu; Liu, Yun; Zhao, Yusheng; Daemen, Luke L; Brown, Craig; Timofeeva, Tatiana V; Ma, Shengqian; Zhou, Hong-Cai

    2008-07-30

    A highly stable porous lanthanide metal-organic framework, Y(BTC)(H2O).4.3H2O (BTC = 1,3,5-benzenetricarboxylate), with pore size of 5.8 A has been constructed and investigated for hydrogen storage. Gas sorption measurements show that this porous MOF exhibits highly selective sorption behaviors of hydrogen over nitrogen gas molecules and can take up hydrogen of about 2.1 wt % at 77 K and 10 bar. Difference Fourier analysis of neutron powder diffraction data revealed four distinct D2 sites that are progressively filled within the nanoporous framework. Interestingly, the strongest adsorption sites identified are associated with the aromatic organic linkers rather than the open metal sites, as occurred in previously reported MOFs. Our results provide for the first time direct structural evidence demonstrating that optimal pore size (around 6 A, twice the kinetic diameter of hydrogen) strengthens the interactions between H2 molecules and pore walls and increases the heat of adsorption, which thus allows for enhancing hydrogen adsorption from the interaction between hydrogen molecules with the pore walls rather than with the normally stronger adsorption sites (the open metal sites) within the framework. At high concentration H2 loadings (5.5 H2 molecules (3.7 wt %) per Y(BTC) formula), H2 molecules form highly symmetric novel nanoclusters with relatively short H2-H2 distances compared to solid H2. These observations are important and hold the key to optimizing this new class of rare metal-organic framework (RMOF) materials for practical hydrogen storage applications.

  11. Powder-based adsorbents having high adsorption capacities for recovering dissolved metals and methods thereof

    Science.gov (United States)

    Janke, Christopher J.; Dai, Sheng; Oyola, Yatsandra

    2016-05-03

    A powder-based adsorbent and a related method of manufacture are provided. The powder-based adsorbent includes polymer powder with grafted side chains and an increased surface area per unit weight to increase the adsorption of dissolved metals, for example uranium, from aqueous solutions. A method for forming the powder-based adsorbent includes irradiating polymer powder, grafting with polymerizable reactive monomers, reacting with hydroxylamine, and conditioning with an alkaline solution. Powder-based adsorbents formed according to the present method demonstrated a significantly improved uranium adsorption capacity per unit weight over existing adsorbents.

  12. A Study on the Development of Social Thinking Abilities and Judgment Abilities in Junior High School Students I : Through the Analysis of the Questionnaire Using Contents of the History

    OpenAIRE

    梅津, 正美; 加藤, 寿朗; 前田, 健一; 新見,直子; 大島, 悟; 竹崎, 葉子; 原, 義昭; 前島, 美佐江

    2013-01-01

    The objective of this study is to clarify developmental transformations in social perception through a developmental survey which focuses on social thinking abilities and judgment abilities in junior high school students. This survey and analysis, while assuming social thinking abilities and judgment abilities in the context of social sciences to be composed of the five elements of actual judgment abilities, inductive inference abilities, deductive reasoning abilities, social judgment abiliti...

  13. THE FORMATION OF CREATIVE ABILITIES OF HIGH SCHOOL STUDENTS: STRUCTURAL AND SUBSTANTIVE ASPECTS

    Directory of Open Access Journals (Sweden)

    O. V. LECHER

    2015-01-01

    Full Text Available The article provides a detailed analysis of the problem of development of creative abilities of high school students. The study was conducted by examining the theoretical and practical literature in the field of pedagogy and psychology with reference to the authoritative sources. The article is of topical importance because today the work on the development of creative abilities of university graduates is not effective enough and this problem needs further studies and search of the ways to solve it. The author has carried out a profound work to determine the effectiveness of the fantasy genre as a means of developingcreative abilities, the potential of which to date is not used or is used not in full. The article presents a list of characteristic features of fantasy genre, as well as a brief historical background of this literary trend and its differences from other literary genres. The authors make a detailed analysis of the concepts of creativity, creative personality and creative ability and come to the conclusion about the necessity of in-depth studies of the problem raised in the article and elaboration of effective methods enhancing and developing creative abilities of students.

  14. Persons in the shadow: Assessing the social context of high abilities

    Directory of Open Access Journals (Sweden)

    HANS GRUBER

    2008-06-01

    Full Text Available From a perspective of research on expertise we argue that the analysis of practice and of the growth of social networks is a promising approach to assessing indicators of high ability. Both groups of variables jointly predict how subjects master critical changes or transitional periods in their careers. Although expert performance is frequently an individual matter, the development of expertise crucially depends on the presence of "persons in the shadow" who design practice patterns, direct the subjects' deliberate practice, and motivate them (often extrinsically. We present detailed analyses from the cases of highly successful professionals – a jazz guitarist, a consultant and a scientist – in order to show how individual and social aspects are combined in early expertise development. Thus, these aspects form the crucial components which have to be considered in the assessment of high abilities if an expertise approach is taken.

  15. Highly Efficient Adsorption of Copp er Ions by a PVP-Reduced Graphene Oxide Based On a New Adsorptions Mechanism

    Institute of Scientific and Technical Information of China (English)

    Yongji Zhang; HuiJuan Chi; WenHui Zhang; Youyi Sun; Qing Liang; Yu Gu; Riya Jing

    2014-01-01

    Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time and ions concentration on adsorption capacity were examined. The maximum adsorption capacity of 1689 mg/g was observed at an initial pH value of 3.5 after agitating for 10 min. It was demonstrated that polyvinylpyrrolidone-reduced graphene oxide had a huge adsorption capacity for Cu ions, which was 10 times higher than maximal value reported in previous works. The adsorption mechanism was also discussed by density functional theory. It demonstrates that Cu ions are attracted to surface of reduced graphene oxide by C atoms in reduced graphene oxide modified by polyvinylpyrrolidone through physisorption processes, which may be responsible for the higher adsorption capacity. Our results suggest that polyvinylpyrrolidone-reduced graphene oxide is an effective adsorbent for removing Cu ions in wastewater. It also provides a new way to improve the adsorption capacity of reduced graphene oxide for dealing with the heavy metal ion in wastewater.

  16. Zambian pre-service junior high school science teachers' chemical reasoning and ability

    Science.gov (United States)

    Banda, Asiana

    The purpose of this study was two-fold: examine junior high school pre-service science teachers' chemical reasoning; and establish the extent to which the pre-service science teachers' chemical abilities explain their chemical reasoning. A sample comprised 165 junior high school pre-service science teachers at Mufulira College of Education in Zambia. There were 82 males and 83 females. Data were collected using a Chemical Concept Reasoning Test (CCRT). Pre-service science teachers' chemical reasoning was established through qualitative analysis of their responses to test items. The Rasch Model was used to determine the pre-service teachers' chemical abilities and item difficulty. Results show that most pre-service science teachers had incorrect chemical reasoning on chemical concepts assessed in this study. There was no significant difference in chemical understanding between the Full-Time and Distance Education pre-service science teachers, and between second and third year pre-service science teachers. However, there was a significant difference in chemical understanding between male and female pre-service science teachers. Male pre-service science teachers showed better chemical understanding than female pre-service science teachers. The Rasch model revealed that the pre-service science teachers had low chemical abilities, and the CCRT was very difficult for this group of pre-service science teachers. As such, their incorrect chemical reasoning was attributed to their low chemical abilities. These results have implications on science teacher education, chemistry teaching and learning, and chemical education research.

  17. Electron stimulated carbon adsorption in ultra high vacuum monitored by Auger Electron Spectroscopy (AES)

    CERN Document Server

    Scheuerlein, C

    2001-01-01

    Electron stimulated carbon adsorption at room temperature (RT) has been studied in the context of radiation induced surface modifications in the vacuum system of particle accelerators. The stimulated carbon adsorption was monitored by AES during continuous irradiation by 2.5 keV electrons and simultaneous exposure of the sample surface to CO, CO2 or CH4. The amount of adsorbed carbon was estimated by measuring the carbon Auger peak intensity as a function of the electron irradiation time. Investigated substrate materials are technical OFE copper and TiZrV non-evaporable getter (NEG) thin film coatings, which are saturated either in air or by CO exposure inside the Auger electron spectrometer. On the copper substrate electron induced carbon adsorption from gas phase CO and CO2 is below the detection limit of AES. During electron irradiation of the non-activated TiZrV getter thin films, electron stimulated carbon adsorption from gas phase molecules is detected when either CO or CO2 is injected, whereas the CH4 ...

  18. HIGH TEMPERATURE ADSORPTION OF CO2 ON VARIOUS HYDROTALCITE-LIKE COMPOUNDS

    Science.gov (United States)

    This study describes and quantifies how substitution of the divalent cation and interlayer charge compensating anions affect the CO2 adsorptive capacity of various hydrotalcite-like compounds (Htlcs). Physical and chemical properties of the Htlcs were evaluated using a number of ...

  19. Preferential adsorption of high density lipoprotein (HDL) in blood plasma/polymer interaction

    NARCIS (Netherlands)

    Bantjes, A.; Breemhaar, W.; Beugeling, T.; Brinkman, E.; Ellens, D.J

    1985-01-01

    A few studies on the adsorption of plasma proteins to polymeric surfaces show that major plasma proteins: albumin (Alb), fibrinogen (Fb) and immunoglobulin (IgG) are adsorbed in much smaller quantities from plasma than from protein solutions (1,2). Present results show that this difference in adsorp

  20. Go Ahead, Prove that God Does Not Exist! On High School Students' Ability To Deal with Fallacious Arguments.

    Science.gov (United States)

    Neuman, Yair

    2003-01-01

    Tested the hypothesis that students' ability to identify fallacies is associated with a process of text comprehension. Findings for 184 Israeli high school students suggest that performance in the text comprehension task significantly predicted ability to identify fallacies. (SLD)

  1. A high surface area Zr(IV)-based metal-organic framework showing stepwise gas adsorption and selective dye uptake

    Science.gov (United States)

    Lv, Xiu-Liang; Tong, Minman; Huang, Hongliang; Wang, Bin; Gan, Lei; Yang, Qingyuan; Zhong, Chongli; Li, Jian-Rong

    2015-03-01

    Exploitation of new metal-organic framework (MOF) materials with high surface areas has been attracting great attention in related research communities due to their broad potential applications. In this work, a new Zr(IV)-based MOF, [Zr6O4(OH)4(eddb)6] (BUT-30, H2eddb=4,4‧-(ethyne-1,2-diyl)dibenzoic acid) has been solvothermally synthesized, characterized, and explored for gases and dyes adsorptions. Single-crystal X-ray diffraction analysis demonstrates a three-dimensional cubic framework structure of this MOF, in which each Zr6O4(OH)4 building unit is linked by 12 linear eddb ligands. BUT-30 has been found stable up to 400 °C and has a Brunauer-Emmett-Teller (BET) surface area as high as 3940.6 m2 g-1 (based on the N2 adsorption at 77 K) and total pore volume of 1.55 cm3 g-1. It is more interesting that this MOF exhibits stepwise adsorption behaviors for Ar, N2, and CO2 at low temperatures, and selective uptakes towards different ionic dyes.

  2. Adsorption isotherm studies of Cu (II) and Co (II) in high concentration aqueous solutions on photocatalytically modified diatomaceous ceramic adsorbents

    Science.gov (United States)

    Ajenifuja, E.; Ajao, J. A.; Ajayi, E. O. B.

    2017-01-01

    Photocatalytically modified ceramic adsorbents were synthesized for the removal of high concentration Cu (II) and Co (II) ions from their aqueous solutions. The raw material, diatomaceous aluminosilicate mineral was modified using silver and anatase titanium oxide nanoparticles. Batch adsorption experiment was carried out on the targeted metal ions and the results were analyzed by the Langmuir and Freundlich equation at different concentrations (100-1000 mg/l) and the characteristic parameters for each adsorption isotherm were determined. As-received raw materials do not exhibit any sorption capacity for high concentration Cu2+ and Co2+ adsorbates. However, the adsorption isotherms for modified diatomaceous ceramic adsorbents could be fitted well by the Langmuir model for both Cu2+ and Co2+ with correlation coefficient (R) of up to 0.99953. The highest and lowest monolayer coverage (q max) were 121.803 and 31.289 mg/g for Cu2+ and Co2+, respectively. The separation factor (R L) in the experiment was less than one (capacity (K f) and intensity (n) constants obtained from Freundlich model are 38.832 (Cu2+ on ZEO-T) and 5.801 (Co2+ on STOX-Z).

  3. Hydrogen adsorption and diffusion, and subcritical-crack growth in high strength steels and nickel base alloys

    Science.gov (United States)

    Wei, R. P.; Klier, K.; Simmons, G. W.; Chornet, E.

    1973-01-01

    Embrittlement, or the enhancement of crack growth by gaseous hydrogen in high strength alloys, is of primary interest in selecting alloys for various components in the space shuttle. Embrittlement is known to occur at hydrogen gas pressures ranging from fractions to several hundred atmospheres, and is most severe in the case of martensitic high strength steels. Kinetic information on subcritical crack growth in gaseous hydrogen is sparse at this time. Corroborative information on hydrogen adsorption and diffusion is inadequate to permit a clear determination of the rate controlling process and possible mechanism in hydrogen enhanced crack growth, and for estimating behavior over a range of temperatures and pressures. Therefore, coordinated studies of the kinetics of crack growth, and adsorption and diffusion of hydrogen, using identical materials, have been initiated. Comparable conditions of temperature and pressure will be used in the chemical and mechanical experiments. Inconel 718 alloy and 18Ni(200) maraging steel have been selected for these studies. Results from these studies are expected to provide not only a better understanding of the gaseous hydrogen embrittlement phenomenon itself, but also fundamental information on hydrogen adsorption and diffusion, and crack growth information that can be used directly for design.

  4. A comprehensive test of evolutionarily increased competitive ability in a highly invasive plant species.

    Science.gov (United States)

    Joshi, Srijana; Gruntman, Michal; Bilton, Mark; Seifan, Merav; Tielbörger, Katja

    2014-12-01

    A common hypothesis to explain plants' invasive success is that release from natural enemies in the introduced range selects for reduced allocation to resistance traits and a subsequent increase in resources available for growth and competitive ability (evolution of increased competitive ability, EICA). However, studies that have investigated this hypothesis have been incomplete as they either did not test for all aspects of competitive ability or did not select appropriate competitors. Here, the prediction of increased competitive ability was examined with the invasive plant Lythrum salicaria (purple loosestrife) in a set of common-garden experiments that addressed these aspects by carefully distinguishing between competitive effect and response of invasive and native plants, and by using both intraspecific and interspecific competition settings with a highly vigorous neighbour, Urtica dioica (stinging nettle), which occurs in both ranges. While the intraspecific competition results showed no differences in competitive effect or response between native and invasive plants, the interspecific competition experiment revealed greater competitive response and effect of invasive plants in both biomass and seed production. The use of both intra- and interspecific competition experiments in this study revealed opposing results. While the first experiment refutes the EICA hypothesis, the second shows strong support for it, suggesting evolutionarily increased competitive ability in invasive populations of L. salicaria. It is suggested that the use of naturally co-occurring heterospecifics, rather than conspecifics, may provide a better evaluation of the possible evolutionary shift towards greater competitive ability. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Improving Communicative Ability in English Task-based Teaching in senior high school

    Institute of Scientific and Technical Information of China (English)

    熊洁

    2016-01-01

    Language is an important means of human communication. More and more people have realized that improving the English communicative competence, especially oral English communicative ability is very important. However, the senior high school students’ oral English communicative competence is not optimistic. This paper analyzes the problems existing in the high school students’ communication based on the study of the task-based teaching theory. Task-based teaching method gradually popularized in the high school English classroom teaching due to its emphasis on the change of students’ learning style and the way of teachers’ teaching.

  6. Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

    Directory of Open Access Journals (Sweden)

    M.A. Kameli

    2017-04-01

    Full Text Available Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. Saline-sodic and sodic soil sample was leached in soil column by diluted wastewater of amirkabir sugar manufacture in Khuzestan Province of Iran at constant water head. Sodium, electric conductivity and chemical oxygen demand of soil column leachate were measured per each pore volume. The experimental kinetics of wastewater organic compounds on two saline-sodic and sodic soil were also investigated by three pseudo second order, intra particle diffusion and elovich model. The results of current study showed that electric conductivity of saline-sodic soil was decreased to 90% during 3 initial pore volumes, from other side exchangeable sodium percent of saline-sodic and sodic soil decreased 30 and 71 percent, respectively. There were no significant different between wastewater chemical oxygen demand removal by saline-sodic and sodic soil in both batch and column studies. Wastewater chemical oxygen demand was decreased to 35% during pass through soil column. The results showed that the adsorption kinetics of wastewater organic compounds were best fitted by the pseudo-second order model with 99 percent correlation coefficient (r2=0.99%.

  7. CHARACTERIZATION OF ZSM-5 ZEOLITIC MEMBRANE WITH ADSORPTION METHODS%ZSM-5沸石膜的吸附表征

    Institute of Scientific and Technical Information of China (English)

    樊栓狮; 王金渠

    1999-01-01

    The framework and thickness of synthesized ZSM-5 membranes were characterized using static and dynamic adsorption methods. It is shown that the adsorptive properties of the membranes are the same as ZSM-5 zeolite, the average thickness of the membranes was 13 μm calculated from the adsorptive ability, which matched very well with the result measured by scanning electron micrograph. The results also shown that zeolite membranes have greated adsorptive ability than zeolite powders. The high Si/Al rate zeolite membranes have selective ability on ethanol/water, and this interpreted the separation of ethanol-water mixtures with the membranes.

  8. Analysis of Factors Influencing Interest in STEM Career: Comparison between American and Turkish High School Students with High Ability

    Science.gov (United States)

    Bahar, Abdulkadir; Adiguzel, Tufan

    2016-01-01

    The low number of students studying or applying for STEM subjects and workforce demand has been prioritized in almost all countries policies. This study intended to examine factors that influenced American and Turkish students to pursue a degree or career in STEM-related fields. Participants of the study were 86 high-ability students selected from…

  9. Fitness determinants of repeated-sprint ability in highly trained youth football players.

    Science.gov (United States)

    Spencer, Matt; Pyne, David; Santisteban, Juanma; Mujika, Iñigo

    2011-12-01

    Variations in rates of growth and development in young football players can influence relationships among various fitness qualities. To investigate the relationships between repeated-sprint ability and other fundamental fitness qualities of acceleration, agility, explosive leg power, and aerobic conditioning through the age groups of U11 to U18 in highly trained junior football players. Male players (n = 119) across the age groups completed a fitness assessment battery over two testing sessions. The first session consisted of countermovement jumps without and with arm swing, 15-m sprint run, 15-m agility run, and the 20-m Shuttle Run (U11 to U15) or the Yo-Yo Intermittent Recovery Test, Level 1 (U16 to U18). The players were tested for repeated-sprint ability in the second testing session using a protocol of 6 × 30-m sprints on 30 s with an active recovery. The correlations of repeated-sprint ability with the assorted fitness tests varied considerably between the age groups, especially for agility (r = .02 to .92) and explosive leg power (r = .04 to .84). Correlations of repeated sprint ability with acceleration (r = .48 to .93) and aerobic conditioning (r = .28 to .68) were less variable with age. Repeated-sprint ability associates differently with other fundamental fitness tests throughout the teenage years in highly trained football players, although stabilization of these relationships occurs by the age of 18 y. Coaches in junior football should prescribe physical training accounting for variations in short-term disruptions or impairment of physical performance during this developmental period.

  10. Correlates of tackling ability in high-performance rugby league players.

    Science.gov (United States)

    Gabbett, Tim J; Jenkins, David G; Abernethy, Bruce

    2011-01-01

    This study investigated the tackling ability of high-performance rugby league players and determined the relationship between physiological and anthropometric qualities and tackling ability in these athletes. Twenty professional (National Rugby League) and 17 semiprofessional (Queensland Cup) rugby league players underwent a standardized 1-on-1 tackling drill in a 10-m grid. Video footage was taken from the rear, side, and front of the defending player. Tackling proficiency was assessed using standardized technical criteria. In addition, all players underwent measurements of standard anthropometry (height, body mass, and sum of 7 skinfolds), acceleration (10-m sprint), change of direction speed (505 test), and lower body muscular power (vertical jump). Professional players had significantly greater (p ≤ 0.05) tackling proficiency than semiprofessional players (87.5 ± 2.0 vs. 75.0 ± 2.3%). Professional players were significantly (p ≤ 0.05) older, more experienced, leaner, and had greater acceleration than semiprofessional players. The strongest individual correlates of tackling ability were age (r = 0.41, p ≤ 0.05), playing experience (r = 0.70, p ≤ 0.01), skinfold thickness (r = -0.59, p ≤ 0.01), acceleration (r = 0.41, p ≤ 0.05), and lower body muscular power (r = 0.38, p ≤ 0.05). When hierarchical multiple regression analysis was performed to determine which of the variables predicted tackling ability, playing experience and lower body muscular power were the only variables that contributed significantly (r2 = 0.60, p ≤ 0.01) to the predictive model. From a practical perspective, strength and conditioning coaches should emphasize the development of acceleration, lower body muscular power, and lean muscle mass to improve tackling ability in high-performance rugby league players.

  11. Seed longevity: survival and maintenance of high germination ability of dry seeds.

    Science.gov (United States)

    Rajjou, Loïc; Debeaujon, Isabelle

    2008-10-01

    The seed constitutes the main vector of plant propagation and it is a critical development stage with many specificities. Seed longevity is a major challenge for the conservation of plant biodiversity and for crop success. Seeds possess a wide range of systems (protection, detoxification, repair) allowing them to survive in the dry state and to preserve a high germination ability. Therefore, the seed system provides an appropriate model to study longevity and aging.

  12. The theory of multiple intelligences in the identification of high-ability students

    Directory of Open Access Journals (Sweden)

    Daniel Hernández-Torrano

    2014-01-01

    Full Text Available This study provides a framework to implement the theory of multiple intelligences (MI in the identification of high-ability students in secondary education. The internal structure of three scales to assess students' MI (students, parents and teachers' ratings was analyzed in a sample of 566 students nominated as gifted by their teachers. Participants aged 11 to 16 years (M = 14.85, SD = 1.08. The results indicated differentiated intellectual profiles depending on the informant estimating students' MI. This study provided evidence for two components that allow us to analyze the cognitive competence of high-ability students beyond the areas commonly assessed at school: an academic component composed by the linguistic, logical-mathematical, naturalistic, and visual-spatial intelligences; and a non-academic component statistically loaded by the bodily-kinesthetic, musical and social intelligences. Convergence of the two components in the three scales was evidenced; and correlations between these components and students' objective performance on a psychometric intelligence test were found to be low. Finally, the utility of the MI scales to identify high-ability students in secondary education is discussed.

  13. Highly efficient and selective adsorption of In3+ on pristine Zn/Al layered double hydroxide (Zn/Al-LDH) from aqueous solutions

    Science.gov (United States)

    Barnabas, Mary Jenisha; Parambadath, Surendran; Mathew, Aneesh; Park, Sung Soo; Vinu, Ajayan; Ha, Chang-Sik

    2016-01-01

    A pristine Zn/Al-layered double hydroxide (Zn/Al-LDH) showed excellent adsorption ability and selectivity towards In3+ ions from aqueous solutions. The adsorption behaviour as a function of the contact time, solution pH, ionic strength, and amount of adsorbent under ambient conditions revealed a strong dependency on the pH and ionic strength over In3+ intake. The structure and properties of Zn/Al-LDH and In3+ adsorbed Zn/Al-LDH (In-Zn/Al-LDH) were examined carefully by X-ray diffraction, Fourier transform infrared spectroscopy, N2-sorption/desorption, UV-vis spectroscopy, and X-ray photoelectron spectroscopy. The adsorbent had a sufficient number of active sites that were responsible for the In3+ adsorption and quite stable even after the adsorption process. The selective adsorption of In3+ on Zn/Al-LDH was also observed even from a mixture containing competing ions, such as Mn2+, Co2+, Ni2+, Cd2+, Pb2+, and Cu2+. The adsorption experiments showed that Zn/Al-LDH is a promising material for the pre-concentration and selective removal of In3+ from large volumes of aqueous solutions.

  14. Developing Science Process Skills and Problem Solving Abilities Based on Outdoor Learning in Junior High School

    Directory of Open Access Journals (Sweden)

    S. Wahyuni

    2017-04-01

    Full Text Available This research aims to develop science process skills and problem-solving abilities based on outdoor learning in junior high school. This study uses a mixed method design embedded experimental models. Data was performed in the qualitative and quantitative analysis. Qualitative data analysis is used to determine the science process skills while quantitative data analysis is used to determine the increasing problem-solving ability by using normalized gain (N gain formula. The results show that the science process skills developed at every phase comprise of making observations, formulating hypotheses, experiment, create data, classify and analyze the data, formulating its conclusions, communicate, and apply the concepts and make predictions obtained by the average value of 75.33 in the good category. While the problem-solving ability of students based on outdoor learning also increased by 0.58 in the medium category. The conclusions of this research show that the application of outdoor learning can be teacher use as an alternative to learning, so it is quite effective in developing science process skills and problem-solving abilities.

  15. Gas adsorption and desorption effects on high pressure small volume cylinders and their relevance to atmospheric trace gas analysis

    Science.gov (United States)

    Satar, Ece; Nyfeler, Peter; Pascale, Céline; Niederhauser, Bernhard; Leuenberger, Markus

    2017-04-01

    Long term atmospheric monitoring of trace gases requires great attention to precision and accuracy of the measurement setups. For globally integrated and well established greenhouse gas observation networks, the World Meteorological Organization (WMO) has set recommended compatibility goals within the framework of its Global Atmosphere Watch (GAW) Programme [1]. To achieve these challenging limits, the measurement systems are regularly calibrated with standard gases of known composition. Therefore, the stability of the primary and secondary gas standards over time is an essential issue. Past studies have explained the small instabilities in high pressure standard gas cylinders through leakage, diffusion, regulator effects, gravimetric fractionation and surface processes [2, 3]. The latter include adsorption/desorption, which are functions of temperature, pressure and surface properties. For high pressure standard gas mixtures used in atmospheric trace gas analysis, there exists only a limited amount of data and few attempts to quantify the surface processes [4, 5]. Specifically, we have designed a high pressure measurement chamber to investigate trace gases and their affinity for adsorption on different surfaces over various temperature and pressure ranges. Here, we focus on measurements of CO2, CH4 and CO using a cavity ring down spectroscopy analyzer and quantify the concentration changes due to adsorption/desorption. In this study, the first results from these prototype cylinders of steel and aluminum will be presented. References [1] World Meteorological Organization (WMO), Global Atmosphere Watch.(GAW): Report No. 229, 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2015), 2016. [2] Keeling, R. F., Manning, A. C., Paplawsky, W. J., and Cox, A. C.: On the long-term stability of reference gases for atmospheric O2 /N2 and CO2 measurements, Tellus B, 59, 10.3402/tellusb.v59i1.16964, 2007. [3

  16. Analysis of shale adsorption characteristics and adsorption abnormal cause under high pressure%高压下页岩吸附特性及吸附异常原因分析

    Institute of Scientific and Technical Information of China (English)

    刘小磊; 吴财芳; 夏大平

    2014-01-01

    from gravitation to repulsion ,which leads shale adsorption to increasing slowly to maximum .At this point the adsorption rate and desorption rate are dynamic equilibrium .Under super high pressure in the adsorption late ,shale surface energy tends to zero ,the intermolecular force between methane molecules and shale surface molecules is rapidly increasing repulsion , which leads shale adsorption to decreasing with pressure increasing even negative .There are two main reasons for shale adsorption abnormal :First ,a relatively low shale adsorption and the greater methane molecular diameter than helium result in larger free volume value in the experiment ,which leads to the results of “negative absorption”;Second ,shale methane is in a supercritical adsorption under high pressure and intermolecular has larger repulsion .

  17. A Highly Stable Nanotubular MOF Rotator for Selective Adsorption of Benzene and Separation of Xylene Isomers.

    Science.gov (United States)

    Huang, Wei; Jiang, Jun; Wu, Dayu; Xu, Jun; Xue, Bing; Kirillov, Alexander M

    2015-11-16

    A remarkably stable tubular 3D Zn-MOF with hexagonal channels and a rare ptr topology was prepared under solvothermal conditions for liquid and vapor phase adsorption and separation of the C6-8 aromatic compounds. The material showed preferential affinity for benzene and can effectively separate benzene from its organic analogues under ambient conditions in both vapor and liquid phases. Furthermore, it exhibited preferable uptake of p-xylene over other C8 xylenes.

  18. Unlocking Emergent Talent: Supporting High Achievement of Low-Income, High Ability Students

    Science.gov (United States)

    Olszewski-Kubilius, Paula; Clarenbach, Jane

    2012-01-01

    This report takes a comprehensive look at achievement for low-income promising learners--past, present, and future. At its core, it challenges the nation to move beyond its near-singular focus of achieving minimum performance for all students, to identifying and developing the talent of all students who are capable of high achievement, including…

  19. Acid-base properties and surface complexation modeling of phosphate anion adsorption by wasted low grade iron ore with high phosphorus.

    Science.gov (United States)

    Yuan, Xiaoli; Bai, Chenguang; Xia, Wentang; An, Juan

    2014-08-15

    The adsorption phenomena and specific reaction processes of phosphate onto wasted low grade iron ore with high phosphorus (WLGIOWHP) were studied in this work. Zeta potential and Fourier transform infrared spectroscopy (FTIR) analyses were used to elucidate the interaction mechanism between WLGIOWHP and aqueous solution. The results implied that the main adsorption mechanism was the replacement of surface hydroxyl groups by phosphate via the formation of inner-sphere complex. The adsorption process was characterized by chemical adsorption onto WLGIOWHP. The non-electrostatic model (NEM) was used to simulate the surface adsorption of phosphate onto WLGIOWHP. The total surface site density and protonation constants for NEM (N(T)=1.6×10(-4) mol/g, K(a1)=2.2×10(-4), K(a2)=6.82×10(-9)) were obtained by non-linear data fitting of acid-base titrations. In addition, the NEM was used to establish the surface adsorption complexation modeling of phosphate onto WLGIOWHP. The model successfully predicted the adsorption of phosphate onto WLGIOWHP from municipal wastewater. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. One-step synthesis of a novel N-doped microporous biochar derived from crop straws with high dye adsorption capacity.

    Science.gov (United States)

    Lian, Fei; Cui, Guannan; Liu, Zhongqi; Duo, Lian; Zhang, Guilong; Xing, Baoshan

    2016-07-01

    N-doping is one of the most promising strategies to improve the adsorption capacity and selectivity of carbon adsorbents. Herein, synthesis, characterization and dye adsorption of a novel N-doped microporous biochar derived from direct annealing of crop straws under NH3 is presented. The resultant products exhibit high microporosity (71.5%), atomic percentage of nitrogen (8.81%), and adsorption capacity to dyes, which is about 15-20 times higher than that of original biochar. Specifically, for the sample NBC800-3 pyrolyzed at 800°C in NH3 for 3 h, its adsorption for acid orange 7 (AO7, anionic) and methyl blue (MB, cationic) is up to 292 mg g(-1) and 436 mg g(-1), respectively, which is among the highest ever reported for carbonaceous adsorbents. The influences of N-doping and porous structure on dye adsorption of the synthesized carbons are also discussed, where electrostatic attraction, π-π electron donor-accepter interaction, and Lewis acid-base interaction mainly contribute to AO7 adsorption, and surface area (especially pore-filling) dominates MB adsorption. The N-doped biochar can be effectively regenerated and reused through direct combustion and desorption approaches.

  1. Adaptive mutation of Acetobacter pasteurianus SKU1108 enhances acetic acid fermentation ability at high temperature.

    Science.gov (United States)

    Matsutani, Minenosuke; Nishikura, Mitsuteru; Saichana, Natsaran; Hatano, Tomoyuki; Masud-Tippayasak, Uraiwan; Theergool, Gunjana; Yakushi, Toshiharu; Matsushita, Kazunobu

    2013-05-20

    In vitro adaptation is one of the most challenging subjects in biology to understand adaptive evolution. Microbial adaptation to temperature is not only interesting in terms of understanding the adaptation mechanism, but also useful for industrial applications. In this study, we attempted the in vitro adaptation of Acetobacter pasteurianus SKU1108 by repeating its cultivation under high-temperature acetic acid fermentation conditions. As a result, thermo-adapted strains having the higher fermentation ability than the wild-type strain were obtained. Mutations and/or disruptions in several proteins of the adapted strains were detected with NGS sequencing technology. In particular, two different adapted strains had mutations or disruptions in three specific genes in common, suggesting that these genes are essential for thermotolerance or fermentation at higher temperature. In order to clarify their involvement in thermotolerance, two of the three genes were disrupted and their phenotype was examined. The results showed that mutations of the two proteins, MarR and an amino acid transporter, are partly responsible for higher fermentation ability and/or thermotolerance. Thus, it was suggested that these elevated abilities of the adapted strains are acquired by assembling several single gene mutations including the above two mutations.

  2. A facile, versatile approach to hydroxyl-anchored metal oxides with high Cr(VI) adsorption performance in water treatment

    Science.gov (United States)

    Ma, Ji; Zuo-Jiang, SiZhi; He, Yunhao; Sun, Qinglei; Wang, Yunguo; Liu, Wei; Sun, Shuangshuang; Chen, Kezheng

    2016-11-01

    In this study, a facile and versatile urea-assisted approach was proposed to synthesize Chinese rose-like NiO, pinecone-like ZnO and sponge-like CoO adsorbents. The presence of urea during syntheses endowed these adsorbents with high concentration of surface hydroxyl groups, which was estimated as 1.83, 1.32 and 4.19 mmol [OH-] g-1 for NiO, ZnO and CoO adsorbents, respectively. These surface hydroxyl groups would facilitate the adsorption of Cr(vi) species (e.g. HCrO4-, Cr2O72- and CrO42-) from wastewater by exchanging with hydroxyl protons or hydroxide ions, and hence result in extremely high maximum adsorbed amounts of Cr(vi), being 2974, 14 256 and 408 mg g-1 for NiO, ZnO and CoO adsorbents in the pH range of 5.02-5.66 at 298 K, respectively. More strikingly, the maximum adsorbed amounts of Cr(vi) would be greatly enhanced as the adsorbing temperature is increased, and even amount to 23 411 mg g-1 for ZnO adsorbents at 323 K. Based on the kinetics and equilibrium studies of adsorptive removal of Cr(vi) from wastewater, our synthetic route will greatly improve the adsorptivity of the as-synthesized metal-oxide adsorbents, and hence it will shed new light on the development of high-performance adsorbents.

  3. Radiation synthesis of a new amidoximated UHMWPE fibrous adsorbent with high adsorption selectivity for uranium over vanadium in simulated seawater

    Science.gov (United States)

    Gao, Qianhong; Hu, Jiangtao; Li, Rong; Xing, Zhe; Xu, Lu; Wang, Mouhua; Guo, Xiaojing; Wu, Guozhong

    2016-05-01

    A new kind of highly efficient adsorbent material has been fabricated in this study for the purpose of extracting uranium from seawater. Ultra-high molecular weight polyethylene (UHMWPE) fiber was used as a trunk material for the adsorbent, which was prepared by a series of modification reactions, as follows: (1) grafting of glycidyl methacrylate (GMA) and methyl acrylate (MA) onto UHMWPE fibers via 60Co γ-ray pre-irradiation; (2) aminolyzation of UHMWPE fiber by the ring-opening reaction between of epoxy groups PGMA and ethylene diamine (EDA); (3) Michael addition of amino groups with acrylonitrile (AN) to yield nitrile groups; (4) amidoximation of the attached nitrile moieties by hydroxylamine in dimethyl sulfoxide-water mixture. Modified UHMWPE fibers were characterized by means of attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to confirm the attachment of amidoxime (AO) groups onto the UHMWPE fibers. The results of X-ray diffraction (XRD) and single fiber tensile strength verified that the modified UHMWPE fiber retained excellent mechanical properties at a low absorbed radiation dose. The adsorption performance of the UHMWPE fibrous adsorbent was evaluated by subjecting it to an adsorption test in simulated seawater using a continuous-flow mode. The amount of uranium adsorbed by this AO-based UHMWPE fibrous adsorbent was 1.97 mg-U/g after 42 days. This new adsorbent also showed high selectivity for the uranyl ion, and its selectivity for metal ions was found to decrease in the following order: U>Cu>Fe>Ca>Mg>Ni>Zn>Pb>V>Co. The adsorption selectivity for uranium is significantly higher than that for vanadium. In addition, preparation of this modified adsorbent consumes much smaller amounts of the toxic acrylonitrile monomer than the conventional preparation methods of AO-based polyethylene fibers.

  4. The identification and inclusion of students with characteristics of high abilities/giftedness: relevant discussions

    Directory of Open Access Journals (Sweden)

    Tatiane Negrini

    2008-12-01

    Full Text Available Thinking about education in general and about the advances that have been coming up, brings us to reflect on the proposal of the inclusive school. The Brazilian educational policies point in this direction and new propositions appear to the school in order to understand how to make significant changes in the daily education. Accordingly, this article is to hold a discussion regarding the identification of students with high abilities/giftedness, articulating with some ideas proposed by the inclusive education. It is with that highlight the importance of identifying these students for a more genuine inclusion of these students in the educational context. In this sense, is used as input theoretical Gardner (1995, Renzulli (2004, Perez (2004, Virgolim (2007, Vieira (2005, among other authors who assist in the discussion of this issue. The considerations made about the high abilities and their process of identification highlight the importance of a great attention facing the process of identification and relevance of this to the actual inclusion of students with high skills in the educational context. Since they are not identified, these students may not be receiving the necessary guidance to learn and develop their potential, often distancing themselves from colleagues and friends. Thus, it is a debate about the appropriate identification of these students and how it can contribute to the inclusion of them.

  5. Ferromagnetic Fe-based Amorphous Alloy with High Glass-forming Ability

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A ferromagnetic amorphous Fe73Al4Ge2Nb1P10C6B4 alloy with highglass-forming ability was synthesized by melt spinning. The supercooled liquid region before crystallization reaches about 65.7 K. The crystallized structure consists of α-Fe, Fe3B, FeB, Fe3P and Fe3C phases. The Febased amorphous alloy exhibits good magnetic properties with a high saturation magnetization and a low saturated magnetostriction. The crystallization leads to an obvious decrease in the soft magnetic properties.

  6. The Impact of Motor Abilities on Belly Dance Performance in Female High School Students

    OpenAIRE

    Srhoj, Ljerka; Mihaljević, Dodi; Jukić, Josefina

    2008-01-01

    The aim of the study was to determine the relation of motor abilities and belly dance performance in female high school students, 1st to 4th graders aged 15–18 years. A battery of 19 motor tests were used and nine belly dance elements evaluated in the study sample that included 148 students aged 15–16 (1st and 2nd graders) and 123 students aged 17–18 (3rd and 4th graders). Factor analysis of the motor space isolated six factors in either study group: in 1st and 2nd graders, the fi...

  7. Attention or instruction: Do sustained attentional abilities really differ between high and low hypnotisable persons?

    Science.gov (United States)

    Martin, Jean-Rémy; Sackur, Jérôme; Dienes, Zoltan

    2017-03-07

    Previous research has suggested that highly hypnotisable participants ('highs') are more sensitive to the bistability of ambiguous figures-as evidenced by reporting more perspective changes of a Necker cube-than low hypnotisable participants ('lows'). This finding has been interpreted as supporting the hypothesis that highs have more efficient sustained attentional abilities than lows. However, the higher report of perspective changes in highs in comparison to lows may reflect the implementation of different expectation-based strategies as a result of differently constructed demand characteristics according to one's level of hypnotisability. Highs, but not lows, might interpret an instruction to report perspective changes as an instruction to report many changes. Using a Necker cube as our bistable stimulus, we manipulated demand characteristics by giving specific information to participants of different hypnotisability levels. Participants were told that previous research has shown that people with similar hypnotisability as theirs were either very good at switching or maintaining perspective versus no information. Our results show that highs, but neither lows nor mediums, were strongly influenced by the given information. However, highs were not better at maintaining the same perspective than participants with lower hypnotisability. Taken together, these findings favour the view that the higher sensitivity of highs in comparison to lows to the bistability of ambiguous figures reflect the implementation of different strategies.

  8. Surface shear rheology of hydrophobin adsorption layers: laws of viscoelastic behaviour with applications to long-term foam stability

    NARCIS (Netherlands)

    Danov, K.D.; Radulova, G.M.; Kralchevsky, P.A.; Golemanov, K.; Stoyanov, S.D.

    2012-01-01

    The long-term stabilization of foams by proteins for food applications is related to the ability of proteins to form dense and mechanically strong adsorption layers that cover the bubbles in the foams. The hydrophobins represent a class of proteins that form adsorption layers of extraordinary high s

  9. Gas adsorption properties of highly porous metal-organic frameworks containing functionalized naphthalene dicarboxylate linkers.

    Science.gov (United States)

    Sim, Jaeung; Yim, Haneul; Ko, Nakeun; Choi, Sang Beom; Oh, Youjin; Park, Hye Jeong; Park, SangYoun; Kim, Jaheon

    2014-12-28

    Three functionalized metal-organic frameworks (MOFs), MOF-205-NH2, MOF-205-NO2, and MOF-205-OBn, formulated as Zn4O(BTB)4/3(L), where BTB is benzene-1,3,5-tribenzoate and L is 1-aminonaphthalene-3,7-dicarboxylate (NDC-NH2), 1-nitronaphthalene-3,7-dicarboxylate (NDC-NO2) or 1,5-dibenzyloxy-2,6-naphthalenedicarboxylate (NDC-(OBn)2), were synthesized and their gas (H2, CO2, or CH4) adsorption properties were compared to those of the un-functionalized, parent MOF-205. Ordered structural models for MOF-205 and its derivatives were built based on the crystal structures and were subsequently used for predicting porosity properties. Although the Brunauer-Emmett-Teller (BET) surface areas of the three MOF-205 derivatives were reduced (MOF-205, 4460; MOF-205-NH2, 4330; MOF-205-NO2, 3980; MOF-205-OBn, 3470 m(2) g(-1)), all three derivatives were shown to have enhanced H2 adsorption capacities at 77 K and CO2 uptakes at 253, 273, and 298 K respectively at 1 bar in comparison with MOF-205. The results indicate the following trend in H2 adsorption: MOF-205 MOF-205-NO2 MOF-205-NH2 MOF-205-OBn. MOF-205-OBn showed good ideal adsorbed solution theory (IAST) selectivity values of 6.5 for CO2/N2 (15/85 in v/v) and 2.7 for CO2/CH4 (50/50 in v/v) at 298 K. Despite the large reduction (-22%) in the surface area, MOF-205-OBn displayed comparable total volumetric CO2 (at 48 bar) and CH4 (at 35 bar) storage capacities with those of MOF-205 at 298 K: MOF-205-OBn, 305 (CO2) and 112 (CH4) cm(3) cm(-3), and for MOF-205, 307 (CO2) and 120 (CH4) cm(3) cm(-3), respectively.

  10. A high plant density reduces the ability of maize to use soil nitrogen.

    Science.gov (United States)

    Yan, Peng; Pan, Junxiao; Zhang, Wenjie; Shi, Junfang; Chen, Xinping; Cui, Zhenling

    2017-01-01

    Understanding the physiological changes associated with high grain yield and high N use efficiency (NUE) is important when increasing the plant density and N rate to develop optimal agronomic management. We tested the hypothesis that high plant densities resulting in crowding stress reduce the ability of plants to use the N supply post-silking, thus decreasing the grain yield and NUE. In 2013 and 2014, a field experiment, with five N-application rates and three plant densities (6.0, 7.5, and 9.0 plants m-2), was conducted in the North China Plain (NCP). The calculated maximum grain yield and agronomic use efficiency (AEN) at a density of 7.5 plants m-2 were 12.4 Mg ha-1 and 39.3 kg kg-1, respectively, which were significantly higher than the values obtained at densities of 6.0 (11.3 Mg ha-1 and 30.2 kg kg-1) and 9.0 plant m-2 (11.7 Mg ha-1 and 27.8 kg kg-1). A high plant density of 9.0 plants m-2 decreased the post-silking N accumulation, leaf N concentration and net photosynthesis, which reduced the post-silking dry matter production, resulting in a low yield and NUE. Although a relatively low grain yield was observed at a density of 9.0 plants m-2, the optimal N rate increased from 150 to 186 kg N ha-1 at a density of 7.5 plants m-2. These results indicate that high plant densities with crowding stress reduce the ability of plants to use soil N during the post-silking period, and high rate of N fertilizer was needed to increase grain yield. We conclude that selecting the appropriate plant density combined with optimal N management could increase grain yields and the NUE in the NCP.

  11. Carbonaceous materials for adsorptive refrigerators

    Science.gov (United States)

    Buczek, B.; Wolak, E.

    2012-06-01

    Carbon monoliths prepared from hard coal precursors were obtained. The porous structure of the monoliths was evaluated on the basis of nitrogen adsorption — desorption equilibrium data. The investigated monoliths have a well-developed microporous structure with significant specific surface area (S BET ). Equilibrium studies of methanol vapour adsorption were used to characterize the methanol adsorptive capacity that was determined using a volumetric method. The heat of wetting by methanol was determined in order to estimate the energetic effects of the adsorption process. The results of the investigations show that all monoliths exhibit high adsorption capacity and high heat of wetting with methanol.

  12. Three dimensional MOF-sponge for fast dynamic adsorption.

    Science.gov (United States)

    Li, Huizeng; Li, Mingzhu; Li, Wenbo; Yang, Qiang; Li, Yanan; Gu, Zhenkun; Song, Yanlin

    2017-02-22

    Nowadays, environmental pollution is a big problem. Metal organic frameworks (MOFs) provide a novel strategy for exhaust gases adsorption and toxic pollutants removal. We proposed a facile and versatile method to prepare a highly efficient three dimensional MOF-sponge by coating MOF crystals on polyurethane sponge surface, mimicking the porous structure of the marine animal, sponge. Owing to combination of the spatial structure of the commercial sponge and the excellent adsorption capacity of MOF coatings, the MOF-sponge possessed good permeability and high dynamic adsorption capacity. Dynamic adsorption ability of the prepared Cu3(BTC)2-sponge was demonstrated by flowing gas-mixtures of NH3/N2 and an aquatic solution of Rhodamine B through it, with a capacity of 101.6 mg g(-1) and 8.8 mg g(-1) for NH3 and Rhodamine B, respectively.

  13. Selection of compositions with high glass forming ability in the Ni-Nb-B alloy system

    Directory of Open Access Journals (Sweden)

    Marcio Andreato Batista Mendes

    2012-10-01

    Full Text Available A combination of an extension of the topological instability "λ criterion" and the "average electronegativity" has been recently reported in the literature to predict compositions with high glass-forming ability (GFA. In the present work, both criteria have been applied to select the Ni61.0Nb36.0B3 alloy with a high glass-forming ability. Ingots were prepared by arc-melting and were used to produce ribbons processed by the melt-spinning technique further characterized by differential scanning calorimetry (DSC, X-ray diffraction (XRD and scanning electron microscopy (SEM. The Ni61.0Nb36.0B3 alloy revealed a complete amorphization and supercooled liquid region ΔTx = 68 K. In addition, wedge-shaped samples were prepared using copper mold casting in order to determine the critical thickness for amorphous formation. Scanning electron microscopy (SEM revealed that fully amorphous samples could be obtained, reaching up to ~800 µm in thickness.

  14. An adsorbent with a high adsorption capacity obtained from the cellulose sludge of industrial residues.

    Science.gov (United States)

    Orlandi, Géssica; Cavasotto, Jéssica; Machado, Francisco R S; Colpani, Gustavo L; Magro, Jacir Dal; Dalcanton, Francieli; Mello, Josiane M M; Fiori, Márcio A

    2017-02-01

    One of the major problems in effluent treatment plants of the cellulose and paper industry is the large amount of residual sludge generated. Therefore, this industry is trying to develop new methods to treat such residues and to use them as new products, such as adsorbents. In this regard, the objective of this work was to develop an adsorbent using the raw activated sludge generated by the cellulose and paper industry. The activated cellulose sludge, after being dried, was chemically activated with 42.5% (v/v) phosphoric acid at 85 °C for 1 h and was charred at 500 °C, 600 °C and 700 °C for 2 h. The efficiency of the obtained adsorbent materials was evaluated using kinetic tests with methylene blue solutions. Using the adsorption kinetics, it was verified that the three adsorbents showed the capacity to adsorb dye, and the adsorbent obtained at a temperature of 600 °C showed the highest adsorption capacity of 107.1 mg g(-1). The kinetic model that best fit the experimental data was pseudo-second order. The Langmuir-Freudlich isotherm adequately described the experimental data. As a result, the cellulose sludge generated by the cellulose and paper industries could be used as an adsorbent.

  15. Ductile Bulk Aluminum-Based Alloy with Good Glass-Forming Ability and High Strength

    Institute of Scientific and Technical Information of China (English)

    ZHUO Long-Chao; PANG Shu-Jie; WANG Hui; ZHANG Tao

    2009-01-01

    Based on a new approach for designing glassy alloy compositions,bulk Al-based alloys with good glass-forming ability (GFA) are synthesized.The cast Al86Si0.5Ni4.06Co2.94 Y6Sc0.5 rod with a diameter of 1 mm shows almost fully amorphous structure besides about 5% fcc-Al nucleated in the center of the rod.The bulk alloy with high Al concentration exhibits an ultrahigh yield strength of 1.18 Gpa and maximum strength of 1.27 Gpa as well as an obvious plastic strain of about 2.4% during compressive deformation.This light Al-based alloy with good GFA and mechanical properties is promising as a new high specific strength material with good deformability.

  16. Preparation, characterization and adsorption properties of chitosan modified magnetic graphitized multi-walled carbon nanotubes for highly effective removal of a carcinogenic dye from aqueous solution

    Science.gov (United States)

    Zhu, HuaYue; Fu, YongQian; Jiang, Ru; Yao, Jun; Liu, Li; Chen, YanWen; Xiao, Ling; Zeng, GuangMing

    2013-11-01

    Novel chitosan-modified magnetic graphitized multi-walled carbon nanotubes (CS-m-GMCNTs) were synthesized via a suspension cross-linking method. Composition, morphology and magnetic properties of as-prepared CS-m-GMCNTs were characterized by XRD, SEM-EDS, BET and VSM. The large saturation magnetization (12.27 emu g-1) allows fast separation of CS-m-GMCNTs from treated aqueous solution. The adsorption of congo red (CR) on CS-m-GMCNTs was strongly dependent on pH, temperature of the aqueous phase and adsorbent dosage. Up to 100 and 94.58% color removal could be achieved in 100 min contact time with 10 and 50 mg L-1 of initial concentrations, respectively. The adsorption capacity of CR onto CS-m-GMCNTs could reach 262.9 mg g-1. The pseudo-second-order kinetic model with high correlation coefficients (R2 > 0.999) was suitable to describe the process of CR adsorption onto CS-m-GMCNTs. The Langmuir model fitted the adsorption isotherm data better than the Freundlich model. Values of thermodynamic parameters (ΔG°, ΔH° and ΔS°) indicated that the adsorption process was strongly dependent on temperature of the aqueous phase, and spontaneous and endothermic process in nature. Therefore, CS-m-GMCNTs adsorbent displays main advantages of excellent dispersion, convenience separation and high adsorption capacity, which implies their potential application in the environmental cleanup.

  17. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    Science.gov (United States)

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  18. Zeolite Y adsorbents with high vapor uptake capacity and robust cycling stability for potential applications in advanced adsorption heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Li, XS; Narayanan, S; Michaelis, VK; Ong, TC; Keeler, EG; Kim, H; Mckay, IS; Griffin, RG; Wang, EN

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg2+ ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg, Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the lab-scale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N-2 sorption, Al-27/Si-29 MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2nd law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N-2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. (C) 2014 Elsevier Inc. All rights reserved.

  19. Zeolite Y Adsorbents with High Vapor Uptake Capacity and Robust Cycling Stability for Potential Applications in Advanced Adsorption Heat Pumps.

    Science.gov (United States)

    Li, Xiansen; Narayanan, Shankar; Michaelis, Vladimir K; Ong, Ta-Chung; Keeler, Eric G; Kim, Hyunho; McKay, Ian S; Griffin, Robert G; Wang, Evelyn N

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg(2+) ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg,Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the labscale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N2 sorption, (27)Al/(29)Si MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2(nd) law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications.

  20. High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

    Directory of Open Access Journals (Sweden)

    Yuki Ueda

    2009-11-01

    Full Text Available This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coefficient of performance (COP and the specific cooling power (SCP, are compared with conventional cascading-without-mass-recovery and single-stage cycles. The paper also presents the effect of the adsorbent mass on performance. The results show that the proposed cycle with mass recovery produces as high of a COP as the COP that is produced by the conventional cascading cycle. However, it produces a lower SCP than that of the single-stage cycle.

  1. Age-related differences in repeated-sprint ability in highly trained youth football players.

    Science.gov (United States)

    Mujika, Inigo; Spencer, Matt; Santisteban, Juanma; Goiriena, Juan Jose; Bishop, David

    2009-12-01

    In this study, we investigated the age-related differences in repeated-sprint ability and blood lactate responses in 134 youth football players. Players from the development programme of a professional club were grouped according to their respective under-age team (U-11 to U-18). Following familiarization, the participants performed a repeated-sprint ability test [6 x 30-m sprints 30 s apart, with active recovery (2.0-2.2 m . s(-1)) between sprints]. The test variables were total time, percent sprint decrement, and post-test peak lactate concentration. Total time improved from the U-11 to U-15 age groups (range 33.15 +/- 1.84 vs. 27.25 +/- 0.82 s), whereas no further significant improvements were evident from U-15 to U-18. No significant differences in percent sprint decrement were reported among groups (range 4.0 +/- 1.0% to 5.5 +/- 2.1%). Post-test peak lactate increased from one age group to the next (range 7.3 +/- 1.8 to 12.6 +/- 1.6 mmol . l(-1)), but remained constant when adjusted for age-related difference in body mass. Peak lactate concentration was moderately correlated with sprint time (r = 0.70, P > 0.001). Our results suggest that performance in repeated-sprint ability improves during maturation of highly trained youth football players, although a plateau occurs from 15 years of age. In contrast to expectations based on previous suggestions, percent sprint decrement during repeated sprints did not deteriorate with age.

  2. The Impact of Active Visualisation of High School Students on the Ability to Memorise Verbal Definitions

    Directory of Open Access Journals (Sweden)

    Anamarija Šmajdek

    2016-12-01

    Full Text Available The era of visual communication influences the cognitive strategies of the individual. Education, too, must adjust to these changes, which raises questions regarding the use of visualisation in teaching. In the present study, we examine the impact of visualisation on the ability of high school students to memorise text. In the theoretical part of the research, we first clarify the concept of visualisation. We define the concept of active visualisation and visualisation as a means of acquiring and conveying knowledge, and we describe the different kinds of visualisation (appearance-based analogies and form-based analogies, specifically defining appearance-based schemata visualisations (where imagery is articulated in a typical culturally trained manner. In the empirical part of the research, we perform an experiment in which we evaluate the effects of visualisation on students’ ability to memorise a difficult written definition. According to the theoretical findings, we establish two hypotheses. In the first, we assume that the majority of the visualisations that students form will be appearance-based schemata visualisations. This hypothesis is based on the assumption that, in visualisation, people spontaneously use analogies based on imagery and schemas that are typical of their society. In the second hypothesis, we assume that active visualisation will contribute to the students’ ability to memorise text in a statistically significant way. This hypothesis is based on the assumption that the combination of verbal and visual experiences enhances cognitive learning. Both hypotheses were confirmed in the research. As our study only dealt with the impact of the most spontaneous type of appearance based schemata visualisations, we see further possibilities in researching the influence of visualisations that are more complex formally.

  3. The Impact of Problem-Based Learning Approach to Senior High School Students’ Mathematics Critical Thinking Ability

    Directory of Open Access Journals (Sweden)

    Reviandari Widyatiningtyas

    2015-07-01

    Full Text Available The study was report the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students’ prior mathematical ability to student’s mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from excellent and moderate school level. The research instruments a set of mathematical critical thinking ability test, and the data were analyzed by using two ways ANOVA and t-test. The research found that the problem based learning approach has significant impact to the ability of students’ mathematics critical thinking in terms of school level and students’ prior mathematical abilities. Furthermore. This research also found that there is no interaction between learning approach and school level, and learning approach and students’ prior mathematics ability to students’ mathematics critical thinking ability.

  4. MOF-derived ZnO and ZnO@C composites with high photocatalytic activity and adsorption capacity.

    Science.gov (United States)

    Yang, Seung Jae; Im, Ji Hyuk; Kim, Taehoon; Lee, Kunsil; Park, Chong Rae

    2011-02-15

    Nanostructured ZnO materials have unique and highly attractive properties and have inspired interest in their research and development. This paper presents a facile method for the preparation of novel ZnO-based nanostructured architectures using a metal organic framework (MOF) as a precursor. In this approach, ZnO nanoparticles and ZnO@C hybrid composites were produced under several heating and atmospheric (air or nitrogen) conditions. The resultant ZnO nanoparticles formed hierarchical aggregates with a three-dimensional cubic morphology, whereas ZnO@C hybrid composites consisted of faceted ZnO crystals embedded within a highly porous carbonaceous species, as determined by several characterization methods. The newly synthesized nanomaterials showed relatively high photocatalytic decomposition activity and significantly enhanced adsorption capacities for organic pollutants. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Highly flexible NiCo2O4/CNTs doped carbon nanofibers for CO2 adsorption and supercapacitor electrodes.

    Science.gov (United States)

    Iqbal, Nousheen; Wang, Xianfeng; Ahmed Babar, Aijaz; Yu, Jianyong; Ding, Bin

    2016-08-15

    Controllable synthesis of carbon nanofibers (CNFs) with hierarchical porosity and high flexibility are extremely desirable for CO2 adsorption and energy storage applications. Herein, we report a nickel cobaltite/carbon nanotubes doped CNFs (NiCo2O4/CNTs CNFs) mesoporous membrane that shows well-developed flexibility, tailored pore structure, hydrophobic character, and high stability. Ascribed to these unique features, NiCo2O4/CNTs CNFs membrane shows high CO2 capture of 1.54mmol/g at 25°C and 1.0bar, and electrochemical measurements for supercapacitors exhibit good performance with specific capacitances of 220F/g (in 1M KOH) at a current density of 1A/g. The successful synthesis of such hybrid membrane provides new insight into development of various multifunctional applications.

  6. Effect of Self-etch Adhesives on Self-sealing Ability of High-Copper Amalgams

    Science.gov (United States)

    Moazzami, Saied Mostafa; Moosavi, Horieh; Moddaber, Maryam; Parvizi, Reza; Moayed, Mohamad Hadi; Mokhber, Nima; Meharry, Michael; B Kazemi, Reza

    2016-01-01

    Statement of the Problem: Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. Purpose: The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap in the early hours after setting by means of Electro-Chemical Tests (ECTs). Materials and Method: Thirty cylindrical cavities of 4.5mm x 4.7mm were prepared on intact bicuspids. The samples were divided into five main groups of application of Adhesive Resin (AR)/ liner/ None (No), on the cavity floor. The first main group was left without an AR/ liner (No). In the other main groups, the types of AR/ liner used were I-Bond (IB), Clearfil S3 (S3), Single Bond (SB) and Varnish (V). Each main group (n=6) was divided into two subgroups (n=3) according to the types of the amalgams used, either admixed ANA 2000 (ANA) or spherical Tytin (Tyt). The ECTs, Open Circuit Potential (OCP), and the Linear Polarization Resistance (LPR) for each sample were performed and measured 48 hours after the completion of the samples. Results: The Tyt-No and Tyt-IB samples showed the highest and lowest OCP values respectively. In LPR tests, the Rp values of ANA-V and Tyt-V were the highest (lowest corrosion rate) and contrarily, the ANA-IB and Tyt-IB samples, with the lowest pH levels, represented the lowest Rp values (highest corrosion rates). Conclusion: Some self-etch adhesives may increase interfacial corrosion potential and self-sealing ability of high-copper amalgams. PMID:27942548

  7. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments

    Science.gov (United States)

    de Vries, Ronald P.; Gruppen, Harry; Kabel, Mirjam A.

    2015-01-01

    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments. PMID:26237450

  8. The Munich High Ability Test Battery (MHBT: A multidimensional, multimethod approach

    Directory of Open Access Journals (Sweden)

    CHRISTOPH PERLETH

    2008-06-01

    Full Text Available After a brief introduction the theoretical basis of the Munich High Ability Test-Battery (MHBT will be outlined in the first part of the article. The MHBT has been developed in the framework of the Munich longitudinal study of giftedness and talent. The MHBT includes not only cognitive predictors measuring several dimensions and types of giftedness concerning intellectual, creative or social abilities etc., but also giftedness-relevant non-cognitive personality and social moderators measuring interests, motivations, learning emotions, self-concepts or family and school climate, educational style, quality of instruction, etc. The MHBT-instruments (different scales and dimensions are described in greater detail.In the second part of the article, after dealing with the objectivity, the reliability, and the validity of the MHBT, the authors discuss the standardization procedure including the development of grade-based T-norms respectively as well as several talent-profiles, e.g. of gifted achievers vs. underachievers, intellectual, creative, social talents or linguistic, math, science talent profiles etc. Finally, examples of talent search for gifted programs and case studies on the basis of MHBT should illustrate multidimensional identification procedures.The MHBT fulfills the most relevant assessment tasks belonging to the gifted educational and counseling practice. The usefulness of the MHBT in the framework of giftedness research as well as of gifted program evaluation studies has also been proven in the last decade. Hence the MHBT offers many opportunities to assessing giftedness and talent.

  9. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments.

    Science.gov (United States)

    Jurak, Edita; Patyshakuliyeva, Aleksandrina; de Vries, Ronald P; Gruppen, Harry; Kabel, Mirjam A

    2015-01-01

    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments.

  10. Imitated prosodic fluency predicts reading comprehension ability in good and poor high school readers

    Directory of Open Access Journals (Sweden)

    Mara Breen

    2016-07-01

    Full Text Available Researchers have established a relationship between beginning readers’ silent comprehension ability and their prosodic fluency, such that readers who read aloud with appropriate prosody tend to have higher scores on silent reading comprehension assessments. The current study was designed to investigate this relationship in two groups of high school readers: Specifically Poor Comprehenders (SPCs, who have adequate word level and phonological skills but poor reading comprehension ability, and a group of age- and decoding skill-matched controls. We compared the prosodic fluency of the two groups by determining how effectively they produced prosodic cues to syntactic and semantic structure in imitations of a model speaker’s production of syntactically and semantically varied sentences. Analyses of pitch and duration patterns revealed that speakers in both groups produced the expected prosodic patterns; however, controls provided stronger durational cues to syntactic structure. These results demonstrate that the relationship between prosodic fluency and reading comprehension continues past the stage of early reading instruction. Moreover, they suggest that prosodically fluent speakers may also generate more fluent implicit prosodic representations during silent reading, leading to more effective comprehension.

  11. Dendritic silica nanomaterials (KCC-1) with fibrous pore structure possess high DNA adsorption capacity and effectively deliver genes in vitro.

    Science.gov (United States)

    Huang, Xiaoxi; Tao, Zhimin; Praskavich, John C; Goswami, Anandarup; Al-Sharab, Jafar F; Minko, Tamara; Polshettiwar, Vivek; Asefa, Tewodros

    2014-09-16

    The pore size and pore structure of nanoporous materials can affect the materials' physical properties, as well as potential applications in different areas, including catalysis, drug delivery, and biomolecular therapeutics. KCC-1, one of the newest members of silica nanomaterials, possesses fibrous, large pore, dendritic pore networks with wide pore entrances, large pore size distribution, spacious pore volume and large surface area--structural features that are conducive for adsorption and release of large guest molecules and biomacromolecules (e.g., proteins and DNAs). Here, we report the results of our comparative studies of adsorption of salmon DNA in a series of KCC-1-based nanomaterials that are functionalized with different organoamine groups on different parts of their surfaces (channel walls, external surfaces or both). For comparison the results of our studies of adsorption of salmon DNA in similarly functionalized, MCM-41 mesoporous silica nanomaterials with cylindrical pores, some of the most studied silica nanomaterials for drug/gene delivery, are also included. Our results indicate that, despite their relatively lower specific surface area, the KCC-1-based nanomaterials show high adsorption capacity for DNA than the corresponding MCM-41-based nanomaterials, most likely because of KCC-1's large pores, wide pore mouths, fibrous pore network, and thereby more accessible and amenable structure for DNA molecules to diffuse through. Conversely, the MCM-41-based nanomaterials adsorb much less DNA, presumably because their outer surfaces/cylindrical channel pore entrances can get blocked by the DNA molecules, making the inner parts of the materials inaccessible. Moreover, experiments involving fluorescent dye-tagged DNAs suggest that the amine-grafted KCC-1 materials are better suited for delivering the DNAs adsorbed on their surfaces into cellular environments than their MCM-41 counterparts. Finally, cellular toxicity tests show that the KCC-1-based

  12. A study on multifunction heat pipe type high efficient adsorption refrigerator using compound adsorbent-ammonia

    Institute of Scientific and Technical Information of China (English)

    LU Zisheng; WANG Ruzhu; WANG Liwei; CHEN Chuanjuan

    2006-01-01

    A multifunction heat pipe adsorption refrigerator is designed, which uses solidified compound adsorbent of CaCl2 and activated carbon as adsorbent. Two work conditions, ice-maker driven by the exhaust heat from diesel engine and air-condi- tioning powered by solar energy, are studied. SCP (specific cooling power) and COP (coefficient of per- formance) for different conditions are analyzed. The optimum average SCP and COP for the refrigerator powered by waste heat of diesel engine are 770.4 W/kg and 0.39 at about -20℃ evaporating tem- perature. The optimum average SCP and COP for the refrigerator powered by solar energy are 524.2 W/kg and 0.27 at about 5.6℃ evaporating tempera- ture.

  13. Topotactic growth, selective adsorption, and adsorption-driven photocatalysis of protonated layered titanate nanosheets.

    Science.gov (United States)

    Wu, Qili; Yang, Xianfeng; Liu, Jia; Nie, Xin; Huang, Yongliang; Wen, Yuping; Khan, Javid; Khan, Wasim U; Wu, Mingmei; An, Taicheng

    2014-10-22

    Layered titanates with selective adsorption ability and adsorption-driven photocatalytic property can be quite attractive due to their potential applications in water purification. In this work, lepidocrocite-like layered protonated titanate (H2Ti2O5·H2O, denoted as HTO) nanosheets were successfully synthesized by an ion-exchange process. It turns out that this layered structure displays an abundant and selective adsorption toward the fluoroquinolone pharmaceutical compared with some large dye molecules due to a size selectivity of the interlayer spacing of HTO and the molecular horizontal size, as well as their electrostatic interaction. The uptake ability of HTO could be readily controlled through adjusting the pH values of adsorbate solution, and the maximum uptake capacity was achieved at the pH value of about 5.5 for ciprofloxacin (CIP) and 6.5 for moxifloxacin (MOX). The adsorption amount of smaller nalidixic acid (NAL) showed an increasing tendency as the pH value decreased. Moreover, the two-dimensional layered crystal structure also permits such HTO nanosheets to have a large percentage of (010) faces exposed, which is considerably provided by the interlayer surfaces of these nanosheets. The (010) surface has a similar Ti and O atomic arrangement as to the highly reactive anatase TiO2(001) one. Due to these specific characteristics, these HTO nanosheets show excellent photocatalytic activity in degrading CIP under UV light irradiation as well as possess a superior adsorption ability to remove CIP from aqueous solution selectively and efficiently. The photocatalytic reaction is believed to be mainly conducted on the active anatase (001)-like interlayer (010) surfaces of the layered structures since the as-prepared HTO performs an adsorption-driven molecular recognitive photocatalytic reaction.

  14. EFFECT OF LEARNING WITH ABDUCTIVE-DEDUCTIVE STRATEGY TOWARDS THE ACHIEVEMENT OF REASONING ABILITY OF HIGH SCHOOL STUDENTS

    Directory of Open Access Journals (Sweden)

    Ali Shodikin

    2017-09-01

    Full Text Available The purpose of this study was to investigate the effect of learning with abductive-deductive strategy towards the achievement of mathematical reasoning abilities of high school students. Research carried out an experimental pretest-posttest design and the control group was not randomized in class XI student at one high school in Pati, Central Java, Indonesia. Data analysis was conducted quantitative research based on early mathematical ability categories (KAM and overall. The results showed that the achievement of mathematical reasoning abilities that students acquire learning abductive-deductive strategy better than students who received the expository learning. In more detail of KAM categories, only middle category that show achievement of mathematical reasoning abilities better. While in upper and under categories have the same reasoning abilities achievements. This research is expected teachers can encourage students to do abduction and deduction in the learning achievement of students’ mathematical reasoning abilities.

  15. The Enhancement of Mathematical Reasoning Ability of Junior High School Students by Applying Mind Mapping Strategy

    Science.gov (United States)

    Ayal, Carolina S.; Kusuma, Yaya S.; Sabandar, Jozua; Dahlan, Jarnawi Afgan

    2016-01-01

    Mathematical reasoning ability, are component that must be governable by the student. Mathematical reasoning plays an important role, both in solving problems and in conveying ideas when learning mathematics. In fact there ability are not still developed well, even in middle school. The importance of mathematical reasoning ability (KPM are…

  16. Changing the Pond, Not the Fish: Following High-Ability Students across Different Educational Environments

    Science.gov (United States)

    Makel, Matthew C.; Lee, Seon-Young; Olszewki-Kubilius, Paula; Putallaz, Martha

    2012-01-01

    Big-fish-little-pond effect (BFLPE) research (e.g., Marsh & Parker, 1984) has found that perceptions of academic ability are generally positively related to individual ability and negatively related to classroom and school average ability. However, BFLPE research typically relies on environmental differences as a between-subjects factor. Unlike…

  17. Soft-ferromagnetic bulk glassy alloys with large magnetostriction and high glass-forming ability

    Directory of Open Access Journals (Sweden)

    Jiawei Li

    2011-12-01

    Full Text Available The effect of Dy addition on the glass-forming ability (GFA, magnetostriction as well as soft-magnetic properties and fracture strength in FeDyBSiNb glassy alloys was investigated. In addition to the increase of supercooled liquid region from 55 to 100 K, the addition of Dy is effective in approaching alloy to an eutectic point and increasing the saturation magnetostrction (λs. Accordingly, bulk glassy alloy (BGA rods with diameters up to 4 mm were produced, which exhibit a large λs as high as 65×10-6. Besides, the BGA system exhibits superhigh fracture strength of 4000 MPa, combined with good soft-magnetic properties.

  18. Optimized cultivation of highly-efficient degradation bacterial strains and their degradation ability towards pyrene

    Institute of Scientific and Technical Information of China (English)

    HOU Shuyu; ZHANG Qingmin; DUO Miao; ZHANG Yang; SUN Hongwen

    2007-01-01

    Two bacterial strains,Pyl and Py4,have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon-pyrene as the single carbon source.It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp..The pyrene degradation ability of separated Pyl,Py4 and the consortium of equal Pyl and Py4 was studied in this project.It is shown that pyrene degradation rates were 88% in 10hr by Py1,84% in 14hr by Py4,and 88% in 8hr by the consortium.It was also determined that the best degradation temperatures were 37℃ and pH 7.0 respectively.The influence of different nutrient substrates added in the degradation experiments was also studied.It was shown that sodium salicylate,sodium acetate and yeast exuact had obvious simulative effect,but glucose had no obvious effect.

  19. Selective adsorption and separation of organic dyes from aqueous solution on polydopamine microspheres.

    Science.gov (United States)

    Fu, Jianwei; Xin, Qianqian; Wu, Xuechen; Chen, Zhonghui; Yan, Ya; Liu, Shujun; Wang, Minghuan; Xu, Qun

    2016-01-01

    Polydopamine (PDA) microspheres, synthesized by a facile oxidation polymerization route, were evaluated as a potential adsorbent for selective adsorption and separation of organic dyes. The adsorption processes towards nine water-soluble dyes (anionic dyes: methyl orange (MO), eosin-Y (EY), eosin-B (EB), acid chrome blue K (ACBK), neutral dye: neutral red (NR), and cationic dyes: rhodamine B (RhB), malachite green (MG), methylene blue (MB), safranine T (ST)) were thoroughly investigated. The adsorption selectivity of organic dyes onto PDA microspheres was successfully applied for the separation of dyes mixtures. Various influential factors such as solution pH, temperature, and contact time were employed to ascertain the optimal condition for adsorption of representative organic dyes including MB, MG and NR. The pseudo-first-order and pseudo-second-order kinetics models were used to fit the adsorption kinetics process. Five isothermal adsorption models (Langmuir, Dubnin-Radushkevich, Temkin, Freundlich and Harkins-Jura) were used to investigate the adsorption thermodynamics properties. The results showed that the PDA microspheres owned good selective adsorption ability towards cationic dyes. The adsorption kinetics process conformed to the pseudo-second-order kinetics model and the Langmuir isotherm model was more appropriate for tracing the adsorption behavior than other isotherm models. Thus, we can conclude PDA microspheres may be a high-efficiency selective adsorbent towards some cationic dyes. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Development of adsorbent from Teflon waste by radiation induced grafting: equilibrium and kinetic adsorption of dyes.

    Science.gov (United States)

    Goel, N K; Kumar, Virendra; Pahan, S; Bhardwaj, Y K; Sabharwal, S

    2011-10-15

    Mutual radiation grafting technique was employed to graft polyacrylic acid (PAA) onto Polytetrafluoroethylene (Teflon) scrap using high energy gamma radiation. Polyacrylic acid-g-Teflon (PAA-g-Teflon) adsorbent was characterized by grafting extent measurement, FTIR spectroscopy, SEM and wet ability & surface energy analysis. The PAA-g-Teflon adsorbent was studied for dye adsorption from aqueous solution of basic dyes, namely, Basic red 29 (BR29) and Basic yellow 11 (BY11). The equilibrium adsorption data were analyzed by Langmuir and Freundlich adsorption isotherm models, whereas, adsorption kinetics was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models. Equilibrium adsorption of BR29 was better explained by Langmuir adsorption model, while that of BY11 by Freundlich adsorption model. The adsorption capacity for BY11 was more than for BR29. Separation factor (R(L)) was found to be in the range 0 dyes. Higher coefficient of determination (r(2) > 0.99) and better agreement between the q(e,cal) and q(e,exp) values suggested that pseudo-second order kinetic model better represents the kinetic adsorption data. The non-linearity obtained for intra-particle diffusion plot indicated, more than one process is involved in the adsorption of basic dyes. The desorption studies showed that ~95% of the adsorbed dye could be eluted in suitable eluent. Copyright © 2011. Published by Elsevier B.V.

  1. Brianyoungite/Graphene Oxide Coordination Composites for High-Performance Cu(2+) Adsorption and Tunable Deep-Red Photoluminescence.

    Science.gov (United States)

    Zhu, Xiaobin; Shan, Yun; Xiong, Shijie; Shen, Jiancang; Wu, Xinglong

    2016-06-22

    Graphene oxide (GO) is a good adsorbent for heavy-metal ions because the oxygen functional groups offer active adsorption sites, but a small-size GO with dense oxygen-containing groups has high water solubility causing difficulty in separation. Herein, GO is bound to large brianyoungite (BY) by Zn-O coordination via a hydrothermal reaction that produces BY-GO composites with hollow spherical and flakelike morphologies that are easy to remove. By producing abundant oxygen-containing groups on GO, the Cu(2+) adsorption capacity increases to 1724.1 mg/g, which is the highest value in graphene-related materials. The experimental and theoretical analysis clearly shows that the infrared spectral shifts toward the low-frequency side of C-O-H and O═C-O bending vibrations in the BY-GO composites stem from the Zn(2+) (or Cu(2+)) coordination with O atoms in GO. The BY-GO also exhibits tunable deep-red photoluminescence up to 750 nm with a quantum yield of about 1%, which may be useful in infrared optoelectronic devices and solar energy exploitation. The photoluminescence which is different from that previously reported from chemically derived GO can be attributed to the optical transition in the disorder-induced localized states of the carbon-oxygen functional groups.

  2. The Uncommon Channel-Based Ln-MOFs for Highly Selective Fe(3+) Detection and Superior Rhodamine B Adsorption.

    Science.gov (United States)

    Xing, Shanghua; Bing, Qiming; Song, Lifei; Li, Guanghua; Liu, Jingyao; Shi, Zhan; Feng, Shouhua; Xu, Ruren

    2016-11-02

    Two new isostructural 3D lanthanide-organic frameworks [H2 N(Me)2 ] [Ln3 (OH)(bpt)3 (H2 O)3 ] (DMF)2 ⋅(H2 O)4 (1-Ln; Ln=Sm and Eu) with a 1D channel (25 Å) have been successfully assembled from the rare trinuclear [Ln3 (OH)(COO)9 ] clusters and biphenyl-3,4',5-tricarboxylic acid (H3 bpt) and exhibit high stability towards water in the pH range 3-10. MOF 1-Eu is a promising luminescent probe for sensing Fe(3+) in aqueous solution and is also selective towards rhodamine B (RhB) with a superior adsorption capacity of 735 mg g(-1) , which is the highest among the reported Ln-MOFs for RhB removal so far. Periodic DFT calculations further confirmed the selective adsorption of rhodamine B over other dyes. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Adsorption of the Inflammatory Mediator High-Mobility Group Box 1 by Polymers with Different Charge and Porosity

    Directory of Open Access Journals (Sweden)

    Carla Tripisciano

    2014-01-01

    Full Text Available High-mobility group box 1 protein (HMGB1 is a conserved protein with a variety of biological functions inside as well as outside the cell. When released by activated immune cells, it acts as a proinflammatory cytokine. Its delayed release has sparked the interest in HMGB1 as a potential therapeutic target. Here, we studied the adsorption of HMGB1 to anionic methacrylate-based polymers as well as to neutral polystyrene-divinylbenzene copolymers. Both groups of adsorbents exhibited efficient binding of recombinant HMGB1 and of HMGB1 derived from lipopolysaccharide-stimulated peripheral blood mononuclear cells. The adsorption characteristics depended on particle size, porosity, accessibility of the pores, and charge of the polymers. In addition to these physicochemical parameters of the adsorbents, modifications of the molecule itself (e.g., acetylation, phosphorylation, and oxidation, interaction with other plasma proteins or anticoagulants (e.g., heparin, or association with extracellular microvesicles may influence the binding of HMGB1 to adsorbents and lead to preferential depletion of HMGB1 subsets with different biological activity.

  4. Dissolution improvement of solid self-emulsifying drug delivery systems of fenofi brate using an inorganic high surface adsorption material

    Directory of Open Access Journals (Sweden)

    Shazly Gamal

    2015-03-01

    Full Text Available Solidification of lipid formulations using adsorbents is a recent technique attracting great interest due to its favourable properties including flexibility in dose division, reduction of intra-subject and inter-subject variability, improvement in efficacy/safety profile and enhancement of physical/ chemical stability. The current study aims to convert liquid self-emulsifying/nanoemulsifying drug delivery systems (SEDDS/SNEDDS into solid SEDDS/SNEDDS and to assess how adsorption of the drug onto an inorganic high surface area material, NeusilinR grade US2 (NUS2, affects its in vitro dissolution performance. Lipid formulation classification systems (LFCS Type III formulations were designed for the model anti-cholesterol drug fenofibrate. NUS2 was used to solidify the SEDDS/SNEDDS. Particle size and SEM analyses of solid SEDDS/SNEDDS powder were carried out to investigate the adsorption efficiency. In vitro dissolution studies were conducted to compare the developed formulations with the marketed product. The results of characterization studies showed that the use of 50 % (m/m adsorbent resulted in superior flowability and kept the drug stable is amorphous state. Dissolution studies allow the conclusion that the formulation containing a surfactant of higher water solubility (particularly, Type IIIB SNEDDS has comparably faster and higher release profiles than Type IIIA (SEDDS and marketed product

  5. Some effects of gas adsorption on the high temperature volatile release behavior of a terrestrial basalt, tektite and lunar soil

    Science.gov (United States)

    Graham, D. G.; Muenow, D. W.; Gibson, E. K., Jr.

    1979-01-01

    Mass pyrograms obtained from high-temperature, mass psectrometric pyrolysis of a glassy theoleiitic submarine basalt and a tektite, ground in air to less than 64 microns, have shown N2 and SO release patterns very similar to those from the pyrolysis of mature lunar soil fines. The N2 and CO release behavior from the terrestrial samples reproduces the biomodal, high-temperature (approximately 700 and 1050 C) features from the lunar samples. Unground portions of the basalt and tektite show no release of N2 and CO during pyrolysis. Grinding also alters the release behavior and absolute amounts of H2O and CO2. It is suggested that adsorption of atmospheric gases in addition to solar wind implantation of ions may account for the wide range of values in previously reported concentrations of carbon and nitrogen from lunar fines.

  6. High-expanding cortical regions in human development and evolution are related to higher intellectual abilities.

    Science.gov (United States)

    Fjell, Anders M; Westlye, Lars T; Amlien, Inge; Tamnes, Christian K; Grydeland, Håkon; Engvig, Andreas; Espeseth, Thomas; Reinvang, Ivar; Lundervold, Astri J; Lundervold, Arvid; Walhovd, Kristine B

    2015-01-01

    Cortical surface area has tremendously expanded during human evolution, and similar patterns of cortical expansion have been observed during childhood development. An intriguing hypothesis is that the high-expanding cortical regions also show the strongest correlations with intellectual function in humans. However, we do not know how the regional distribution of correlations between intellectual function and cortical area maps onto expansion in development and evolution. Here, in a sample of 1048 participants, we show that regions in which cortical area correlates with visuospatial reasoning abilities are generally high expanding in both development and evolution. Several regions in the frontal cortex, especially the anterior cingulate, showed high expansion in both development and evolution. The area of these regions was related to intellectual functions in humans. Low-expanding areas were not related to cognitive scores. These findings suggest that cortical regions involved in higher intellectual functions have expanded the most during development and evolution. The radial unit hypothesis provides a common framework for interpretation of the findings in the context of evolution and prenatal development, while additional cellular mechanisms, such as synaptogenesis, gliogenesis, dendritic arborization, and intracortical myelination, likely impact area expansion in later childhood.

  7. Highly efficient and selective adsorption of In{sup 3+} on pristine Zn/Al layered double hydroxide (Zn/Al-LDH) from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Barnabas, Mary Jenisha; Parambadath, Surendran; Mathew, Aneesh; Park, Sung Soo [Department of Polymer Science and Engineering, Pusan National University, Geumjeong-gu, Busan 46241 (Korea, Republic of); Vinu, Ajayan [Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, #75 Corner College and Cooper Road, Brisbane 4072, QLD (Australia); Ha, Chang-Sik, E-mail: csha@pnu.edu [Department of Polymer Science and Engineering, Pusan National University, Geumjeong-gu, Busan 46241 (Korea, Republic of)

    2016-01-15

    A pristine Zn/Al-layered double hydroxide (Zn/Al-LDH) showed excellent adsorption ability and selectivity towards In{sup 3+} ions from aqueous solutions. The adsorption behaviour as a function of the contact time, solution pH, ionic strength, and amount of adsorbent under ambient conditions revealed a strong dependency on the pH and ionic strength over In{sup 3+} intake. The structure and properties of Zn/Al-LDH and In{sup 3+} adsorbed Zn/Al-LDH (In–Zn/Al-LDH) were examined carefully by X-ray diffraction, Fourier transform infrared spectroscopy, N{sub 2}-sorption/desorption, UV–vis spectroscopy, and X-ray photoelectron spectroscopy. The adsorbent had a sufficient number of active sites that were responsible for the In{sup 3+} adsorption and quite stable even after the adsorption process. The selective adsorption of In{sup 3+} on Zn/Al-LDH was also observed even from a mixture containing competing ions, such as Mn{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cd{sup 2+}, Pb{sup 2+}, and Cu{sup 2+}. The adsorption experiments showed that Zn/Al-LDH is a promising material for the pre-concentration and selective removal of In{sup 3+} from large volumes of aqueous solutions. - Highlights: • A pristine Zn/Al-layered double hydroxide showed good selectivity for In{sup 3+} ions. • The material exhibited a maximum In{sup 3+} intake of 205 mg g{sup −1} at pH 6. • The materials showed good affinity of In{sup 3+} over Cu{sup 2+} and Pb{sup 2+} from ion mixtures.

  8. Effective removal of hexavalent chromium from aqueous solutions by adsorption on mesoporous carbon microspheres.

    Science.gov (United States)

    Zhou, Jianguo; Wang, Yuefeng; Wang, Jitong; Qiao, Wenming; Long, Donghui; Ling, Licheng

    2016-01-15

    High-surface-area mesoporous carbon microspheres were successfully synthesized by a spraying method with the purpose of removing Cr(VI) from waste water. Various factors influencing the adsorption of Cr(VI), including pH, adsorption temperature, and contact time were studied. As the adsorption process was pH dependent, it showed maximum removal efficiency of Cr(VI) at pH 3.0. Pseudo-second-order model was found to best represent the kinetics of Cr(VI) adsorption. The adsorption parameters were determined using both Langmuir and Freundlich isotherm models, and Qm value was as high as 165.3mg/g. The thermodynamic parameters including standard Gibb's free energy (ΔG(0)), standard enthalpy (ΔH(0)) and standard entropy (ΔS(0)) were investigated for predicting the nature of adsorption, which suggested the adsorption was an endothermic and a spontaneous thermodynamically process. Furthermore, Fe3O4-loaded MCMs were prepared to rapidly separate the adsorbent from the solution by a simple magnetic process. Fe3O4-loaded MCMs had a high adsorption capacity of 156.3mg/g, and a good regeneration ability with a capacity of 123.9mg/g for the fifth adsorption-desorption cycle. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. The Impact of Problem-Based Learning Approach to Senior High School Students' Mathematics Critical Thinking Ability

    Science.gov (United States)

    Widyatiningtyas, Reviandari; Kusumah, Yaya S.; Sumarmo, Utari; Sabandar, Jozua

    2015-01-01

    The study reported the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students' prior mathematical ability to student's mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from…

  10. Honors and High-Ability Students: Factors That Predict Academic Efficacy, Critical Thinking Skills, and Academic Goals

    Science.gov (United States)

    Moon, Jessica Lynn

    2012-01-01

    The purpose of the quantitative study was threefold: (a) to examine high-ability students in and outside an honors program at a midwestern comprehensive university to determine differences in background and demographic characteristics between honors participants and nonparticipants of similar ability; (b) to determine differences in academic…

  11. Creative Thinking Ability to Increase Student Mathematical of Junior High School by Applying Models Numbered Heads Together

    Science.gov (United States)

    Lince, Ranak

    2016-01-01

    Mathematical ability of students creative thinking is a component that must be mastered by the student. Mathematical creative thinking plays an important role, both in solving the problem and well, even in high school students. Therefore, efforts are needed to convey ideas in mathematics. But the reality is not yet developed the ability to…

  12. Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

    Science.gov (United States)

    Belen-Ferrer, Bellasanta

    2009-12-01

    This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

  13. 高氟土壤的氟动力学吸附试验研究%Experiment on Fluoride Kinetics Adsorption of High Fluoride Soils

    Institute of Scientific and Technical Information of China (English)

    段江飞; 刘浩; 时孟杰

    2014-01-01

    通过室内水土试验,研究山东高密高氟地区的土壤对氟的动力学吸附特性,并用典型的低氟土试验进行对比。从化学动力学的角度讨论高氟土壤对氟的吸附行为。高氟土壤对氟的吸附有其特殊性;高氟土壤对氟的吸附分为快、慢两个阶段;羟基是影响氟吸附的重要因素。%Through indoor soil test,the article is based on strudies fluorine kinetics adsorption of soils in high density flu-oride region of Shandong Province and comparing by low fluoride soil experiment.It discusses the way of Fluoride adsorp-tion by high fluoride soils from the point of chemical kinetics.The results show that fluoride adsorption by high fluoride soils has its particularity;the tendency of fluoride adsorption is faster at the first stage and slower at the second stage;Hydroxyl is one of the important factors to affect the fluoride adsorption.

  14. A high throughput approach to quantify protein adsorption on combinatorial metal/metal oxide surfaces using electron microprobe and spectroscopic ellipsometry

    Science.gov (United States)

    Byrne, T.; Lohstreter, L.; Filiaggi, M. J.; Bai, Zhijun; Dahn, J. R.

    2008-09-01

    Although metallic biomaterials are widely used, systematic studies of protein adsorption onto such materials are generally lacking. Combinatorial binary films of Al 1-xTi x and Al 1-xNb x (0 ⩽ x ⩽ 1) and corresponding pure element films were produced on glass substrates using a unique magnetron sputtering technique. Fibrinogen and albumin adsorption amounts were measured by wavelength-dispersive spectroscopy (WDS) and spectroscopic ellipsometry (SE) equipment, both high throughput techniques with automated motion stage capabilities. X-ray diffraction revealed that the binary films have crystalline phases present near the ends of the compositional gradient with an amorphous region throughout the interior of the gradient. X-ray photoelectron spectroscopy provided the surface chemistry along the binary films and showed that Al 2O 3 preferentially formed at the surface. Protein adsorption onto these films was found to be closely correlated to the alumina surface fraction, with high alumina content at the surface leading to low amounts of adsorbed fibrinogen and albumin. Protein adsorption amounts obtained with WDS and SE were in excellent agreement for all films. This suggests that this combinatorial materials approach combined with these state-of-the-art, automated high throughput instruments provides a novel way to accurately monitor protein adsorption taking place at the surfaces of these metal/metal oxide materials.

  15. The Republic of the Philippines coalbed methane assessment: based on seventeen high pressure methane adsorption isotherms

    Science.gov (United States)

    Flores, Romeo M.; Stricker, Gary D.; Papasin, Ramon F.; Pendon, Ronaldo R.; del Rosario, Rogelio A.; Malapitan, Ruel T.; Pastor, Michael S.; Altomea, Elmer A.; Cuaresma, Federico; Malapitan, Armando S.; Mortos, Benjamin R.; Tilos, Elizabeth N.

    2006-01-01

    Introduction: The Republic of the Philippines has some 19 coal districts that contain coal deposits ranging from Eocene to Pleistocene in age. These coal districts include: (1) Catanduanes (Eocene); (2) Cebu, Zamboanga Sibuguey, Bukidnon, Maguindanao, Sarangani, and Surigao (Oligocene to Miocene); (3) Batan Island, Masbate, Semirara (including Mindoro), and Quezon-Polilio (lower-upper Miocene); (4) Davao, Negros, and Sorsogon (middle-upper Miocene); (5) Cotabato (lower Miocene-lower Pliocene), Cagayan-Isabella, and Quirino (upper Miocene-Pliocene); (6) Sultan Kudarat (upper Miocene-Pleistocene); and (7) Samar-Leyte (lower Pliocene-Pleistocene). In general, coal rank is directly related to the age of the deposits - for example, the Eocene coal is semi-anthracite and the Pliocene-Pleistocene coal is lignite. Total coal resources in these 19 coal districts, which are compiled by the Geothermal and Coal Resources Development Division (GCRDD) of the Department of Energy of the Philippines, are estimated at a minimum of 2,268.4 million metric tonnes (MMT) (approximately 2.3 billion metric tones). The largest resource (550 MMT) is the subbituminous coal in the Semirara (including Mindoro) coal district, and the smallest (0.7 MMT) is the lignite-subbituminous coal in the Quirino coal district. The combined lignite and subbituminous coal resources, using the classification by GCRDD and including Semirara and Surigao coal districts, are about 1,899.2 MMT, which make up about 84 percent of the total coal resources of the Philippines. The remaining resources are composed of bituminous and semi-anthracite coal. The subbituminous coal of Semirara Island in the Mindoro- Semirara coal district (fig. 2) is known to contain coalbed methane (CBM), with the coal being comparable in gas content and adsorption isotherms to the coal of the Paleocene Fort Union Formation in the Powder River Basin in Wyoming, USA (Flores and others, 2005). As a consequence, the presence of CBM in the

  16. Junior High School English Teachers' Requisite Abilities%初中英语教师应具备的能力

    Institute of Scientific and Technical Information of China (English)

    史建元

    2011-01-01

    初中英语教师应具有观察组织能力,逻辑推理与分析综合能力,语言表达能力,创造能力和运用现代媒体的能力以及拥有“教育机智”的能力,这样才能真正地驾驭自己的教学,从而取得良好的教学效果。%Junior high school English teachers should possess observing and organizing ability, logical reasoning and analyzing ability, language expressive ability, creative ability, the ability of applying modern media and education wisdom ability, only in this way can control teaching and achieve better teaching effect.

  17. Impact of motor abilities on belly dance performance in female high school students.

    Science.gov (United States)

    Srhoj, Ljerka; Mihaljević, Dodi; Jukić, Josefina

    2008-09-01

    The aim of the study was to determine the relation of motor abilities and belly dance performance in female high school students, 1st to 4th graders aged 15-18 years. A battery of 19 motor tests were used and nine belly dance elements evaluated in the study sample that included 148 students aged 15-16 (1st and 2nd graders) and 123 students aged 17-18 (3rd and 4th graders). Factor analysis of the motor space isolated six factors in either study group: in 1st and 2nd graders, the first factor integrated coordination, trunk strength, aerobic and muscle endurance, and speed of lower extremity movements; second factor defined explosive strength; third factor defined flexibility; fourth factor defined rhythm coordination; fifth factor defined equilibrium; and sixth factor defined back musculature strength; in 3rd and 4th graders, the first factor integrated coordination and lower extremity explosive strength; second factor defined flexibility; third factor integrated trunk strength and aerobic-muscular endurance; fourth factor defined equilibrium; fifth factor defined rhythm coordination; and sixth factor defined lower extremity strength. Factor analysis of the scores allocated to particular belly dance elements isolated only one factor as a factor of the general specific ability for belly dance performance. Regression analysis in the latent space indicated the factor of flexibility, which is responsible for muscle tone regulation, to be the best predictor of belly dance performance in 1st and 2nd graders. In 3rd and 4th graders, the factor of rhythm coordination was found to be superior in predicting belly dance performance, followed by the factor of trunk strength and aerobic-muscular endurance, the factor integrating coordination and lower extremity strength, and factor of equilibrium.

  18. Insight into the adsorption mechanisms of vanadium(V) on a high-efficiency biosorbent (Ti-doped chitosan bead).

    Science.gov (United States)

    Liu, Xin; Zhang, Lingfan

    2015-08-01

    In this present study, a new chitosan bead modified with titanium ions (TiCB) was prepared and employed for the adsorption of vanadium ions from aqueous solutions. Batch adsorption experiments were performed to research the effect of various factors, including pH, temperature, contact time and initial concentration of vanadium(V) ions. The adsorption of vanadium was followed by the pseudo second-order kinetic and the Langmuir isotherm model, with a remarkable maximum adsorption capacity of 210 mg/g. The analysis of thermodynamic parameters (ΔG°, ΔH° and ΔS°) revealed that the nature of adsorption was feasible, spontaneous (ΔG°0) process. FTIR, EDS, EMI and XPS studies suggested that the mechanisms of adsorption were possibly attributed to electrostatic attraction, ligand-exchange and redox reaction between TiCB and vanadium ions. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effect of Self-etch Adhesives on Self-sealing Ability of High-Copper Amalgams

    Directory of Open Access Journals (Sweden)

    Saied Mostafa Moazzami

    2016-12-01

    Full Text Available Statement of the Problem: Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. Purpose: The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap in the early hours after setting by means of Electro-Chemical Tests (ECTs. Materials and Method: Thirty cylindrical cavities of 4.5mm x 4.7mm were prepared on intact bicuspids. The samples were divided into five main groups of application of Adhesive Resin (AR/ liner/ None (No, on the cavity floor. The first main group was left without an AR/ liner (No. In the other main groups, the types of AR/ liner used were I-Bond (IB, Clearfil S3 (S3, Single Bond (SB and Varnish (V. Each main group (n=6 was divided into two subgroups (n=3 according to the types of the amalgams used, either admixed ANA 2000 (ANA or spherical Tytin (Tyt. The ECTs, Open Circuit Potential (OCP, and the Linear Polarization Resistance (LPR for each sample were performed and measured 48 hours after the completion of the samples. Results: The Tyt-No and Tyt-IB samples showed the highest and lowest OCP values respectively. In LPR tests, the Rp values of ANA-V and Tyt-V were the highest (lowest corrosion rate and contrarily, the ANA-IB and Tyt-IB samples, with the lowest pH levels, represented the lowest Rp values (highest corrosion rates. Conclusion: Some self-etch adhesives may increase interfacial corrosion potential and self-sealing ability of high-copper amalgams. Keywords ● Electrochemical Test ● Dental Amalgam ● Corrosion ● Self-etch adhesive;

  20. A highly stable amino-coordinated MOF for unprecedented block off N2 adsorption and extraordinary CO2/N2 separation.

    Science.gov (United States)

    Zhang, Ling; Jiang, Ke; Jiang, Mengdie; Yue, Dan; Wan, Yating; Xing, Huabin; Yang, Yu; Cui, Yuanjing; Chen, Banglin; Qian, Guodong

    2016-11-15

    A highly stable amino-coordinated metal-organic framework ZJU-198 has been synthesized and structurally characterized, exhibiting high CO2 uptake of 105.8 cm(3) cm(-3) while blocking off N2 adsorption at 1.0 bar and 298 K, attributed to the unique pore window sizes.

  1. Remarkably high surface visco-elasticity of adsorption layers of triterpenoid saponins

    NARCIS (Netherlands)

    Golemanov, K.; Tcholakova, S.; Denkov, N.; Pelan, E.; Stoyanov, S.D.

    2013-01-01

    Saponins are natural surfactants, with molecules composed of a hydrophobic steroid or triterpenoid group, and one or several hydrophilic oligosaccharide chains attached to this group. Saponins are used in cosmetic, food and pharmaceutical products, due to their excellent ability to stabilize emulsio

  2. Remarkably high surface visco-elasticity of adsorption layers of triterpenoid saponins

    NARCIS (Netherlands)

    Golemanov, K.; Tcholakova, S.; Denkov, N.; Pelan, E.; Stoyanov, S.D.

    2013-01-01

    Saponins are natural surfactants, with molecules composed of a hydrophobic steroid or triterpenoid group, and one or several hydrophilic oligosaccharide chains attached to this group. Saponins are used in cosmetic, food and pharmaceutical products, due to their excellent ability to stabilize

  3. Selection of the Mutants with High Hydroquinone Degradation Ability of Serratia Marcesscen by Plasma Mutation

    Institute of Scientific and Technical Information of China (English)

    YAO Risheng; YOU Qidong; HE Weijing; ZHU Huixia

    2009-01-01

    In this study, an efficient way by plasma induced mutation was applied to improve the hydroquinone degradation capacity of Serratia marcescens AB 90027 (SM27). The results showed that combined with the selection of hydroquinone tolerance, the mutant with high hy-droquinone degradation ability induced by plasma could be achieved. The best dose for plasma mutation was 15 s, which showed a 47.0% higher positive mutation ratio. Besides, the aimed mutant was markedly different from the parent strain (SM27) in colonial traits while cultivated on Kings media. Finally, the hydroquinone degradation ratio reached 70.5% using the induced mutant strain with 1500 mg/L hydroquinone (HQ) after 15 days of cultivation as the selective conditions; however, it was only 46.7% for SM27. The improvement of the degradation capacity by the induced mutant with a high concentration of HQ selection was attributed to its faster growth and higher hydroquinone tolerance compared with that of the parent strain.

  4. [Reading ability of junior high school students in relation to self-evaluation and depression].

    Science.gov (United States)

    Yamashita, Toshiya; Hayashi, Takashi

    2012-01-01

    Guidelines for the diagnosis of reading disorders in elementary school students were published recently in Japan. On the basis of these guidelines, we administrated reading test batteries to 43 Japanese junior high-school students from grade two. The reading test consisted of single sounds, single words, and single sentences. We evaluated the reading speed and the number of reading errors made by the test takers; their performance was compared with the normal value for elementary school students in grade six, as stated in the guidelines. The reading ability of the junior high-school students was not higher than that of the elementary school students. Seven students (16.3%) were found to have reading difficulties (RD group) and they met the criterion for diagnosis of reading disorder as per the guidelines. Three students had difficulties in reading single sounds and single words, but they faced no problems when reading single sentences. It was supposed that the strategies used by the students for reading sentences may have differed from those used for reading single sounds or single words. No significant differences were found between the RD and non-RD group students on scores of scholastic self-evaluation, self-esteem, and depressive symptoms. Therefore, reading difficulty did not directly influence the level of self-evaluation or depression.

  5. MATHEMATICAL UNDERSTANDING AND REPRESENTATION ABILITY OF PUBLIC JUNIOR HIGH SCHOOL IN NORTH SUMATRA

    Directory of Open Access Journals (Sweden)

    Ani Minarni

    2016-01-01

    Full Text Available This paper is the result of first phase of the research about the development of students’ mathematical understanding and representation ability through Joyful Problem-based Learning (JPBL at Public Junior High School in North Sumatera, Indonesia. The population is all of the students of public junior high school (PJHS in North Sumatera. Samples choose based on stratified random sampling. The samples are the students of PJHS 27 Medan, PJHS 1 Percut Sei Tuan, PJHS 1 Tebing Tinggi, and PJHS 2 Pematangsiantar. The techniques used for collecting data is observation, interview, and essay test. The research findings: (1 Based on interview and observation found that conventional approach still use in all of the class of PJHS; The students engagement in learning activity is very low as well as students self-regulated learning; Most of the students do not attain minimal mastery achievement, (2 Based on essay test found that achievement of the students in mathematical understanding and representation test is categories low.

  6. Apoptosis inducing ability of silver decorated highly reduced graphene oxide nanocomposites in A549 lung cancer.

    Science.gov (United States)

    Khan, Merajuddin; Khan, Mujeeb; Al-Marri, Abdulhadi H; Al-Warthan, Abdulrahman; Alkhathlan, Hamad Z; Siddiqui, Mohammed Rafiq H; Nayak, Vadithe Lakshma; Kamal, Ahmed; Adil, Syed F

    2016-01-01

    Recently, graphene and graphene-based materials have been increasingly used for various biological applications due to their extraordinary physicochemical properties. Here, we demonstrate the anticancer properties and apoptosis-inducing ability of silver doped highly reduced graphene oxide nanocomposites synthesized by employing green approach. These nano composites (PGE-HRG-Ag) were synthesized by using Pulicaria glutinosa extract (PGE) as a reducing agent and were evaluated for their anticancer properties against various human cancer cell lines with tamoxifen as the reference drug. A correlation between the amount of Ag nanoparticles on the surface of highly reduced graphene oxide (HRG) and the anticancer activity of nanocomposite was observed, wherein an increase in the concentration of Ag nanoparticles on the surface of HRG led to the enhanced anticancer activity of the nanocomposite. The nanocomposite PGE-HRG-Ag-2 exhibited more potent cytotoxicity than standard drug in A549 cells, a human lung cancer cell line. A detailed investigation was undertaken and Fluorescence activated cell sorting (FACS) analysis demonstrated that the nanocomposite PGE-HRG-Ag-2 showed G0/G1 phase cell cycle arrest and induced apoptosis in A549 cells. Studies such as, measurement of mitochondrial membrane potential, generation of reactive oxygen species (ROS) and Annexin V-FITC staining assay suggested that this compound induced apoptosis in human lung cancer cells.

  7. Batch and kinetic studies of Ni adsorption on highly humified Newfoundland peat

    Energy Technology Data Exchange (ETDEWEB)

    Asapo, E.S.; Coles, C.A. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada). Faculty of Engineering and Applied Science

    2010-07-01

    Metal precipitation and neutralization processes are used to treat effluents produced by the metals industry. Nickel (Ni) mining in Newfoundland and Labrador (NL) may become a source of pollution if lime precipitation techniques are used to treat effluents as an accumulation of the metal in aquatic organisms and plants may pose a health risk to humans and animals. Studies have indicated that peat can be used as a low-cost adsorbent for metals. This study investigated the kinetic and sorption equilibria parameters for the uptake of Ni with saprist NL peat. The aim of the study was to determine how the peat can be used to remove metals from the Ni mining effluents. A pseudo second order kinetic model with regression coefficients characterized kinetic parameters at a solution pH of 5.5 for peat doses of 4, 10, 21 and 40 g per litre with solution concentrations of 24, 50, 125 and 200 mg per litre. Langmuir and Freundlich isotherm equilibrium sorption parameters were determined. The study demonstrated that over 90 percent of Ni removal was obtained using the Langmuir isotherm. The adsorption process was significantly influenced by the peat dose and the initial metal concentration.12 refs., 4 tabs.

  8. High adsorption capacity of two Zn-based metal-organic frameworks by ultrasound assisted synthesis.

    Science.gov (United States)

    Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

    2016-11-01

    Micro- and nano-rods and plates of two 3D, porous Zn(II)-based metal-organic frameworks [Zn(oba)(4-bpdh)0.5]n·(DMF)1.5 (TMU-5) and [Zn(oba)(4-bpmb)0.5]n (DMF)1.5 (TMU-6) were prepared by sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. These MOFs were synthesized using a non-linear dicarboxylate (H2oba=4,4-oxybisbenzoic acid) and two linear N-donor (4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene and 4-bpmb=N(1),N(4)-bis((pyridin-4-yl)methylene)benzene-1,4-diamine) ligands by ultrasonic irradiation. Sonication time and concentration of initial reagents influencing size and morphology of nano-structured MOFs, were also studied. Calcination of TMU-5 and TMU-6 at 550°C under air atmosphere yields ZnO nanoparticles. TMU-5 and TMU-6 exhibited maximum percent adsorption of 96.2% and 92.8% of 100ppm rhodamine B dye, respectively, which obeys first order reaction kinetics.

  9. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation.

    Science.gov (United States)

    Zhang, Yiming; Li, Baiyan; Krishna, Rajamani; Wu, Zili; Ma, Dingxuan; Shi, Zhan; Pham, Tony; Forrest, Katherine; Space, Brian; Ma, Shengqian

    2015-02-14

    The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have been investigated by in situ IR spectroscopic studies and computational calculations, which suggest that π-complexation contributes dominantly to the high ethylene-ethane adsorption selectivity.

  10. Highly enhanced adsorption for the removal of Hg(II) from aqueous solution by Mercaptoethylamine/Mercaptopropyltrimethoxysilane functionalized vermiculites.

    Science.gov (United States)

    Tran, Lytuong; Wu, Pingxiao; Zhu, Yajie; Yang, Lin; Zhu, Nengwu

    2015-05-01

    Vermiculites modified with Mercaptoethylamine (MEA) and 3-Mercaptopropyltrimethoxysilane (MPTMS) were used as effective adsorbents for the removal of Hg(II) from aqueous solution. The physicochemical characteristics of the pristine and functionalized vermiculites were analyzed by XRD, BET, FTIR, SEM, TEM and Zeta potentials, confirming that the vermiculite was successfully functionalized by the organic ligands containing the thiol (SH) metal-chelating groups. Batch adsorption experiments demonstrated that the factors such as initial pH, contact time, temperature, coexisting cations and initial Hg(II) concentration could significantly influence the adsorption behaviors typically for VER and MEA-VER, whereas the adsorption capacity of MPTMS-VER showed negligible dependence on such factors. The maximum adsorption capacity of Hg(II) ions was greatly improved after functionalization, which was in the order of MPTMS-VER>MEA-VER>VER (286.29 μg g(-1), 176.33 μg g(-1), 99.95 μg g(-1), respectively). The adsorption isotherm could be well described with Langmuir model and the kinetic studies indicated that the adsorption process fitted well with the pseudo-second-order model. The calculated thermodynamic parameters suggested that the adsorption process was feasible and spontaneous. The adsorption mechanism of Hg(II) on thiol groups was studied through XPS analysis. Considering the favorable adsorption capacities, thiol-functionalized vermiculites show a promising application in the removal of Hg(II) from wastewater.

  11. METHODS OF COMPARATIVE APPRAISAL OF TITANIUM ALLOYS ABILITY TO THERMAL STRENGTHENING AS A RESULT OF HIGH-TEMPERATURE THERMOMECHANICAL PROCESSING

    Directory of Open Access Journals (Sweden)

    V. N. Fedulov

    2011-01-01

    Full Text Available The methods, enabing to produce the comparative appraisal of the titanium alloy ability to harden as a result of high-temperature thermal-mechanical processing depending on temperature and rate of deformation at forging, is developed.

  12. A porous Cd(II) metal-organic framework with high adsorption selectivity for CO2 over CH4

    Science.gov (United States)

    Zhu, Chunlan

    2017-05-01

    Metal-organic frameworks (MOFs) have attracted a lot of attention in recent decades. We applied a semi-rigid four-carboxylic acid linker to assemble with Cd(II) ions to generate a novel microporous Cd(II) MOF material. Single crystal X-ray diffraction study reveals the different two dimension (2D) layers can be further packed together with an AB fashion by hydrogen bonds (O4sbnd H4⋯O7 = 1.863 Å) to construct a three dimension (3D) supermolecular architecture. The resulting sample can be synthesized under solvothermal reactions successfully, which exhibits high selectivity adsorption of CO2 over CH4 at room temperature. In addition, the obtained sample was characterized by thermal gravimetric analyses (TGA), Fourier-transform infrared spectra (FT-IR), elemental analysis (CHN) and powder X-ray diffraction (PXRD).

  13. Impact of interfacial high-density water layer on accurate estimation of adsorption free energy by Jarzynski's equality

    Science.gov (United States)

    Zhang, Zhisen; Wu, Tao; Wang, Qi; Pan, Haihua; Tang, Ruikang

    2014-01-01

    The interactions between proteins/peptides and materials are crucial to research and development in many biomedical engineering fields. The energetics of such interactions are key in the evaluation of new proteins/peptides and materials. Much research has recently focused on the quality of free energy profiles by Jarzynski's equality, a widely used equation in biosystems. In the present work, considerable discrepancies were observed between the results obtained by Jarzynski's equality and those derived by umbrella sampling in biomaterial-water model systems. Detailed analyses confirm that such discrepancies turn up only when the target molecule moves in the high-density water layer on a material surface. Then a hybrid scheme was adopted based on this observation. The agreement between the results of the hybrid scheme and umbrella sampling confirms the former observation, which indicates an approach to a fast and accurate estimation of adsorption free energy for large biomaterial interfacial systems.

  14. Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

    Science.gov (United States)

    Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

    2008-08-15

    Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

  15. High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

    Directory of Open Access Journals (Sweden)

    Tian Qin

    Full Text Available BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE and sequence-based typing (SBT were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01. The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01. Legionella pneumophila was the most frequently isolated species (98.9%, and the isolated serogroups included serogroups 3 (25.3%, 6 (23.4%, 5 (19.2%, 1 (18.5%, 2 (10.2%, 8 (0.4%, 10 (0.8%, 9 (1.9% and 12 (0.4%. Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control

  16. Adsorbent for p-phenylenediamine adsorption and removal based on graphene oxide functionalized with magnetic cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongxue; Liu, Liangliang; Jiang, Xinyu; Yu, Jingang [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Chen, Xiaohong [Collaborative Innovation Center of Resource-conserving & Environment-friendly Society and Ecological Civilization, Changsha, 410083 (China); Chen, Xiaoqing, E-mail: xqchen@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Collaborative Innovation Center of Resource-conserving & Environment-friendly Society and Ecological Civilization, Changsha, 410083 (China)

    2015-02-28

    Highlights: • Magnetic β-cyclodextrin-graphene oxide (MCG) show high adsorption capacity. • The maximum adsorption capacity was 1102.58 mg/g at 45 °C and pH 8. • MCG can be easily and fast extracted from water by magnetic attraction. • Removal rate of MCG could reach 98% after three times of adsorption. • Adsorption capacity of MCG remained at 81% after five cycles. - Abstract: Recently, graphene oxide (GO) based magnetic nanocomposites have been widely used in an adsorption-based process for the removal of organic pollutants from the water system. In this study, magnetic β-cyclodextrin-graphene oxide nanocomposites (MCG) were synthesized according to covalent binding of magnetic β-cyclodextrin nanoparticles onto the GO surface and the as-made nanocomposites were successfully applied as adsorbents for the adsorption and removal of p-phenylenediamines (PPD). The composition and morphology of prepared materials were characterized by Fourier infrared spectrometry (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Effects of pH, temperature, time and reusability on the adsorption of PPD were investigated, as well as the kinetics and isotherms parameters of the adsorbents were determined. The results indicated that the maximum adsorption capacity of MCG was 1102.58 mg/g at 45 °C and pH 8. The adsorption capacity remained at 81% after five cycles. Removal rate could reach 98% after three times of adsorption. The adsorption process with PPD was found that fitted pseudo-second-order kinetics equations and the Langmuir adsorption model. The results showed the MCG had a good adsorption ability to remove organic pollutants in wastewater.

  17. Individual Differences in Speech and Language Ability Profiles in Areas of High Deprivation

    Science.gov (United States)

    Jordan, Julie-Ann; Coulter, Lorraine

    2017-01-01

    Speech and language ability is not a unitary concept; rather, it is made up of multiple abilities such as grammar, articulation and vocabulary. Young children from socio-economically deprived areas are more likely to experience language difficulties than those living in more affluent areas. However, less is known about individual differences in…

  18. The ability of fungus Mucor racemosus Fresenius to degrade high concentration of detergent

    Directory of Open Access Journals (Sweden)

    Jakovljević Violeta D.

    2014-01-01

    Full Text Available The ability of fungus Mucor racemosus Fresenius to decompose high concentration of commercial detergent (MERIX, Henkel, Serbia was investigated in this study. Fungus was cultivated in liquid growth medium by Czapek with addition of detergent at concentration 0.5% during 16 days. The biochemical changes of pH, redox potential, amount of free and total organic acids, and activity of alkaline phosphatase were evaluated by analysis of fermentation broth. Simultaneously, biodegradation percentage of anionic surfactant of tested detergent was confirmed by MBAS assay. At the same time, the influence of detergent on fungal growth and total dry weight biomass was determined. Detergent at concentration 0.5% influenced on decreasing of pH value and increasing of redox potential as well as increasing of free and total organic acids. Enzyme activity of alkaline phosphatase was reduced by detergent at concentration 0.5%. The fungus was decomposed about 62% of anionic surfactant during 16 day. Due to fungus was produced higher dry weight biomass (53% in relation to control. [Projekat Ministarstva nauke Republike Srbije, br. III 43004

  19. High seed dispersal ability of Pinus canariensis in stands of contrasting density inferred from genotypic data

    Directory of Open Access Journals (Sweden)

    Unai López de Heredia

    2015-04-01

    Full Text Available Aim of the study: Models that combine parentage analysis from molecular data with spatial information of seeds and seedlings provide a framework to describe and identify the factors involved in seed dispersal and recruitment of forest species. In the present study we used a spatially explicit method (the gene shadow model in order to assess primary and effective dispersal in Pinus canariensis. Area of study: Pinus canariensis is endemic to the Canary Islands (Spain. Sampling sites were a high density forest in southern slopes of Tenerife and a low density stand in South Gran Canaria. Materials and methods: We fitted models based on parentage analysis from seeds and seedlings collected in two sites with contrasting stand density, and then compared the resulting dispersal distributions. Main results: The results showed that: 1 P. canariensis has a remarkable dispersal ability compared to other pine species; 2 there is no discordance between primary and effective dispersals, suggesting limited secondary dispersal by animals and lack of Janzen-Connell effect; and 3 low stand densities enhance the extent of seed dispersal, which was higher in the low density stand. Research highlights: The efficient dispersal mechanism of P. canariensis by wind inferred by the gene shadow model is congruent with indirect measures of gene flow, and has utility in reconstructing past demographic events and in predicting future distribution ranges for the species.

  20. A New Look on the Development and Learning of Children with High Abilities

    Directory of Open Access Journals (Sweden)

    Giovana Mattei

    2007-09-01

    Full Text Available When we approach the subject development and learning soon in them it comes the mind the process of education and specific learning of the pertaining to school environment. However we must have clearly that the development as well as learning is complex processes that involves the pertaining not only the school environment but the development of the physical, mental and social of the human being. The human being is not only intellect, is a complex being with strong cognitive and ambient support, of interactions, learnings and consequently development and evolution. This capacity to learn during all the life, exactly without being present in a pertaining school environment, is what in them it becomes only beings capable to be able to interpret, to reveal knowledge, to develop itself socially intellectual and, that is learning in potential. With regard to the children superendowed or carrying of high innumerable abilities doubts and contradictions thus permeat the relative aspects to its development and learning, different visions and perspectives are analyzed in order to contribute and to clarify aspects related to these children special, so that school and educators can assist in significant way these children potentializing his capacities.

  1. Adsorption of ethanol on V2O5 (010) surface for gas-sensing applications: Ab initio investigation

    Science.gov (United States)

    Qin, Yuxiang; Cui, Mengyang; Ye, Zhenhua

    2016-08-01

    The adsorption of ethanol on V2O5 (010) surface was investigated by means of density functional theory (DFT) with a combined generalized gradient approximation (GGA) plus Hubbard U approach to exploit the potential sensing applications. The adsorption configurations were first constructed by considering different orientations of ethanol molecule to V and O sites on the "Hill"- and "Valley"-like regions of corrugated (010) surface. It is found that ethanol molecule can adsorb on whole surface in multiple stable configurations. Nevertheless the molecular adsorption on the "Hill"-like surface is calculated to occur preferentially, and the single coordinated oxygen on "Hill"-like surface (O1(H)) acting as the most energetically favorable adsorption site shows the strongest adsorption ability to ethanol molecule. Surface adsorption of ethanol tunes the electronic structure of V2O5 and cause an n-doping effect. As a consequence, the Fermi levels shift toward the conductive bond increasing the charge carrier concentration of electrons in adsorbed V2O5. The sensitive electronic structure and the multiple stable configurations to ethanol adsorption highlight the high adsorption activity and then the potential of V2O5 (010) surface applied to high sensitive sensor for ethanol vapor detection. Further Mulliken population and Natural bond orbital (NBO) calculations quantify the electron transfer from the adsorbed ethanol to the surface, and correlates the adsorption ability of surface sites with the charge donation and dispersion.

  2. Cognitive abilities and motivational processes in high school students' science achievement and engagement

    Science.gov (United States)

    Lau, Shun

    The dissertation presents two analytic approaches, a variable-centered and person-centered approach, to investigating holistic patterns of the cognitive, motivational, and affective correlates of science achievement and engagement in a sample of 491 10th and 11th grade high-school students. Building on Snow's (1989) idea of two pathways to achievement outcomes, Study 1 adopted a variable-centered approach to examining how cognitive and motivational factors associated with the performance and commitment pathways, respectively, contributed to the prediction of achievement outcomes in science. Results of hierarchical regression analyses showed that (a) students' cognitive abilities were the strongest predictors of their performance in science as measured by standardized test scores; (b) motivational processes enhanced the predictive validity for science test scores and grades beyond the variance accounted for by ability and demography; (c) motivational processes were the strongest predictors of students' commitment to science in the form of situational engagement and anticipated choices of science-related college majors and careers; and (d) competence beliefs served as a point of contact between the performance and commitment pathways. These results are consistent with Snow's (1989) conjecture that both performance and commitment pathway-related factors are necessary for understanding the full range of person-level inputs to achievement outcomes. Study 2 adopted a person-centered approach to examining holistic organizations of psychological factors within individuals and their relations to science achievement and engagement. Four types of students characterized by unique configurations of cognitive, motivational, and affective attributes were identified in both the male and female subsamples using inverse factor analysis. Type membership was found to distinguish students in various indicators of science achievement and engagement. Two of the four types were also found

  3. Apoptosis inducing ability of silver decorated highly reduced graphene oxide nanocomposites in A549 lung cancer

    Directory of Open Access Journals (Sweden)

    Khan M

    2016-03-01

    Full Text Available Merajuddin Khan,1 Mujeeb Khan,1 Abdulhadi H Al-Marri,1 Abdulrahman Al-Warthan,1 Hamad Z Alkhathlan,1 Mohammed Rafiq H Siddiqui,1 Vadithe Lakshma Nayak,2 Ahmed Kamal,2 Syed F Adil1 1Department of Chemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Department of Medicinal Chemistry and Pharmacology, CSIR – Indian Institute of Chemical Technology, Hyderabad, India Abstract: Recently, graphene and graphene-based materials have been increasingly used for various biological applications due to their extraordinary physicochemical properties. Here, we demonstrate the anticancer properties and apoptosis-inducing ability of silver doped highly reduced graphene oxide nanocomposites synthesized by employing green approach. These nano­composites (PGE-HRG-Ag were synthesized by using Pulicaria glutinosa extract (PGE as a reducing agent and were evaluated for their anticancer properties against various human cancer cell lines with tamoxifen as the reference drug. A correlation between the amount of Ag nanoparticles on the surface of highly reduced graphene oxide (HRG and the anticancer activity of nanocomposite was observed, wherein an increase in the concentration of Ag nanoparticles on the surface of HRG led to the enhanced anticancer activity of the nanocomposite. The nanocomposite PGE-HRG-Ag-2 exhibited more potent cytotoxicity than standard drug in A549 cells, a human lung cancer cell line. A detailed investigation was undertaken and Fluorescence activated cell sorting (FACS analysis demonstrated that the nanocomposite PGE-HRG-Ag-2 showed G0/G1 phase cell cycle arrest and induced apoptosis in A549 cells. Studies such as, measurement of mitochondrial membrane potential, generation of reactive oxygen species (ROS and Annexin V-FITC staining assay suggested that this compound induced apoptosis in human lung cancer cells. Keywords: plant extract, graphene/silver nanocomposites, anticancer, apoptosis

  4. [Adsorption behavior of exogenous thorium on soil contaminated by rare earth industries].

    Science.gov (United States)

    Guo, Peng-ran; Jia, Xiao-yu; Duan, Tai-cheng; Qiu, Rong-liang; Chen, Hang-ting

    2009-10-15

    The adsorption behavior of exogenous thorium on soil was studied to evaluate the contaminated risk on soil. The adsorption capacity, equilibrium time, distribution coefficient and desorption ability were investigated by the experiments of static adsorption. The strong adsorption ability of exogenous thorium on soil samples was observed by high adsorption ratio (> 92%) and low desorption ratio ( or = 0.9167) and Elovich equation (R2 > or = 0.8980) were primely fit for describing the thermodynamics and kinetics of the adsorption of exogenous thorium on soil samples, respectively, which indicated that the adsorption was belonged to the nonlinear adsorption, and was affected by the diffusion of thorium on soil surface and in mineral interbed. Sequential extraction procedure was employed to evaluate the bound fractions of exogenous thorium adsorbed on soil samples. Based on the extracted results of thorium fractions, exogenous thorium was presented in the labile nonresidual fractions (over 58%) at the low initial concentration (10(-7) - 10(-6) mol x L(-1)), and nonresidual fractions enhanced with the increase of the initial amount, meanwhile more exogenous throium was transferred to the stable residual fractions.

  5. PREPARATION OF CHOLESTEROL IMPRINTED POLYMERIZED ORGANOGEL AND SELECTIVITY ADSORPTION ABILITY%胆固醇分子印迹聚合有机凝胶的制备及其选择性吸附研究

    Institute of Scientific and Technical Information of China (English)

    张圣祖; 郑敏; 邓帆; 谢琦; 马笑

    2011-01-01

    N-octadecyl maleamic acid (ODMA) as gelator self-assembled in solvent mixture of β-hydroxyethyl methacrylate, methylacrylic acid and polyethylene glycol dimethacrylates-200 in the presence of 3-cholesteryloxycarbonylpropanoic acid (COPA) as template molecule, and turned them into thermally reversible polymerizable organogels. The resultant organogels were subsequently polymerized by in situ UV irradiation.The molecularly-imprinting polymerized organogels were obtained after removal of the template molecules through acetonitrile extracting. The cholesterol molecularly imprinted polymerized organgels (MIPO) showed significantly higher affinity for cholesterol than that for non-imprinted polymerized organgels (NIPO) in water/THF mixture (5:6, V/V). The selectivity experiment indicated that the adsorption amount of MIPO for cholesterol (18.9 mg/g) was higher than that for stigmasterol (4.5 mg/g) and testosterone (3.6 mg/g) within 3 h since the selectivity was based on the specific binding of cholesterol to recognition sites formed in polymers. The adsorption capacity for cholesterol onto MIP0 was found to increase and then decrease, but for stigmasterol and testosterone which was decreased with the increase of ODMA in organogel. The higher concentration of COPA in organogel would result the decrease of the adsorption capacity for cholesterol, but the adsorption capacity for stigmasterol and testosterone remained nearly constant. However, these results could be attributed to the high density of polymer network and stability of imprinted holes.%以N-十八烷基马来酰胺酸(ODMA)为凝胶剂,在甲基丙烯酸β-羟乙酯、甲基丙烯酸、聚乙二醇二甲基丙烯酸酯和模板分子3-胆固醇酰氧基丙酸(COPA)混合物中自组装形成稳定的超分子有机凝胶,经UV原位光聚合,乙腈提取模板分子制备了胆固醇非共价印迹聚合有机凝胶.吸附实验在水/THF中进行.结果显示胆固醇非共价印迹聚合有机凝胶(MIPO)对

  6. The fabrication of highly uniform ZnO/CdS core/shell structures using a spin-coating-based successive ion layer adsorption and reaction method

    Science.gov (United States)

    Joo, Jinmyoung; Kim, Darae; Yun, Dong-Jin; Jun, Hwichan; Rhee, Shi-Woo; Lee, Jae Sung; Yong, Kijung; Kim, Sungjee; Jeon, Sangmin

    2010-08-01

    We developed a successive ion layer adsorption and reaction method based on spin-coating (spin-SILAR) and applied the method to the fabrication of highly uniform ZnO/CdS core/shell nanowire arrays. Because the adsorption, reaction, and rinsing steps occur simultaneously during spin-coating, the spin-SILAR method does not require rinsing steps between the alternating ion adsorption steps, making the growth process simpler and faster than conventional SILAR methods based on dip-coating (dip-SILAR). The ZnO/CdS core/shell nanowire arrays prepared by spin-SILAR had a denser and more uniform structure than those prepared by dip-SILAR, resulting in the higher power efficiency for use in photoelectrochemical cells.

  7. The fabrication of highly uniform ZnO/CdS core/shell structures using a spin-coating-based successive ion layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Jinmyoung; Kim, Darae; Yun, Dong-Jin; Jun, Hwichan; Rhee, Shi-Woo; Lee, Jae Sung; Yong, Kijung; Jeon, Sangmin [System on Chip Chemical Process Research, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang (Korea, Republic of); Kim, Sungjee, E-mail: jeons@postech.ac.kr [Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang (Korea, Republic of)

    2010-08-13

    We developed a successive ion layer adsorption and reaction method based on spin-coating (spin-SILAR) and applied the method to the fabrication of highly uniform ZnO/CdS core/shell nanowire arrays. Because the adsorption, reaction, and rinsing steps occur simultaneously during spin-coating, the spin-SILAR method does not require rinsing steps between the alternating ion adsorption steps, making the growth process simpler and faster than conventional SILAR methods based on dip-coating (dip-SILAR). The ZnO/CdS core/shell nanowire arrays prepared by spin-SILAR had a denser and more uniform structure than those prepared by dip-SILAR, resulting in the higher power efficiency for use in photoelectrochemical cells.

  8. Effect of ethanol and pH on the adsorption of acetaminophen (paracetamol) to high surface activated charcoal, in vitro studies

    DEFF Research Database (Denmark)

    Høgberg, Lotte Christine Groth; Angelo, Helle R; Christophersen, A Bolette

    2002-01-01

    the maximum adsorption capacity for paracetamol for two types of high surface-activated charcoal [Carbomix and Norit Ready-To-Use (not yet registered trademark in Denmark) both from Norit Cosmara, Amersfoort, The Netherlands] in simulated in vivo environments: At pH 1.2 (gastric environment), at pH 7...

  9. Highly selective CO2 adsorption accompanied with low-energy regeneration in a two-dimensional Cu(II) porous coordination polymer with inorganic fluorinated PF6(-) anions.

    Science.gov (United States)

    Noro, Shin-ichiro; Hijikata, Yuh; Inukai, Munehiro; Fukushima, Tomohiro; Horike, Satoshi; Higuchi, Masakazu; Kitagawa, Susumu; Akutagawa, Tomoyuki; Nakamura, Takayoshi

    2013-01-01

    High selectivity and low-energy regeneration for adsorption of CO(2) gas were achieved concurrently in a two-dimensional Cu(II) porous coordination polymer, [Cu(PF(6))(2)(4,4'-bpy)(2)](n) (4,4'-bpy = 4,4'-bipyridine), containing inorganic fluorinated PF(6)(-) anions that can act as moderate interaction sites for CO(2) molecules.

  10. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation

    NARCIS (Netherlands)

    Zhang, Y.; Li, B.; Krishna, R.; Wu, Z.; Ma, D.; Shi, Z.; Pham, T.; Forrest, K.; Space, B.; Ma, S.

    2015-01-01

    The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have

  11. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation

    NARCIS (Netherlands)

    Zhang, Y.; Li, B.; Krishna, R.; Wu, Z.; Ma, D.; Shi, Z.; Pham, T.; Forrest, K.; Space, B.; Ma, S.

    2015-01-01

    The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have b

  12. Adsorption of benzene, cyclohexane and hexane on ordered mesoporous carbon.

    Science.gov (United States)

    Wang, Gang; Dou, Baojuan; Zhang, Zhongshen; Wang, Junhui; Liu, Haier; Hao, Zhengping

    2015-04-01

    Ordered mesoporous carbon (OMC) with high specific surface area and large pore volume was synthesized and tested for use as an adsorbent for volatile organic compound (VOC) disposal. Benzene, cyclohexane and hexane were selected as typical adsorbates due to their different molecular sizes and extensive utilization in industrial processes. In spite of their structural differences, high adsorption amounts were achieved for all three adsorbates, as the pore size of OMC is large enough for the access of these VOCs. In addition, the unusual bimodal-like pore size distribution gives the adsorbates a higher diffusion rate compared with conventional adsorbents such as activated carbon and carbon molecular sieve. Kinetic analysis suggests that the adsorption barriers mainly originated from the difficulty of VOC vapor molecules entering the pore channels of adsorbents. Therefore, its superior adsorption ability toward VOCs, together with a high diffusion rate, makes the ordered mesoporous carbon a promising potential adsorbent for VOC disposal.

  13. Synthesis and Adsorption Properties of Polystyrene-supported Chelating Resins Containing Heterocyclic Functional Groups

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of new chelating resins with incorporating heterocyclic functional groups:pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol co ntaining sulfur. These chelating resins were found to show high adsorption capacities for Ag+, Hg2+, Au3+ and Pd2+, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.

  14. Developing E-Learning Based on Animation Content for Improving Mathematical Connection Abilities in High School Students

    OpenAIRE

    Dedi Rohendi

    2012-01-01

    The purpose of this paper is to develop e-learning based on animation content for improving mathematical connection abilities in senior high school students. The e-learning was developed by using Moddle and the animation content was developed by using macromedia flash. To get the student mathematical conection abilities it uses the instruments of mathematical tests before and after teaching and learning process. The data were analyzed by using t-test and gain value test. The study found that ...

  15. Greater perceived ability to form vivid mental images in individuals with high compared to low BMI.

    Science.gov (United States)

    Patel, Barkha P; Aschenbrenner, Katja; Shamah, Daniel; Small, Dana M

    2015-08-01

    Obese individuals report more frequent food cravings than their lean counterparts. Since mental imagery plays a role in eliciting and maintaining craving we hypothesized that one's ability to image may be associated with body mass index (BMI) and account, at least in part, for the association between BMI and craving. Twenty-five participants (BMI range: 17.7 kg/m(2)-34.2 kg/m(2)) completed three measures of perceived mental imagery ability (The Vividness of Visual Imagery Questionnaire, The Vividness of Olfactory Imagery Questionnaire, The Vividness of Food Imagery Questionnaire), and one measure of craving (Food-Craving Inventory). As predicted, correlation analyses revealed positive associations between BMI and perceived ability to image odors and foods, but not visual objects. Olfactory imagery was singled out as the best predictor of BMI in a hierarchical regression analysis. A second experiment with 57 participants (BMI range: 19.1 kg/m(2)-38.7 kg/m(2)) then confirmed the significant positive association between BMI and perceived ability to image odors. These results raise the possibility that imagery ability may play a role in the heightened food cue reactivity observed in obese individuals. Copyright © 2015. Published by Elsevier Ltd.

  16. Facile and highly efficient removal of trace Gd(III) by adsorption of colloidal graphene oxide suspensions sealed in dialysis bag

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weifan, E-mail: dragon0791@sohu.com [School of Materials Science and Engineering, Nanchang University, Nanchang 330031 (China); Research Center of Rare Earths and Micro/Nano Functional Materials, Nanchang University, Nanchang 330031 (China); Wang, Linlin; Zhuo, Mingpeng; Liu, Yue; Wang, Yiping [School of Materials Science and Engineering, Nanchang University, Nanchang 330031 (China); Li, Yongxiu [Research Center of Rare Earths and Micro/Nano Functional Materials, Nanchang University, Nanchang 330031 (China)

    2014-08-30

    Graphical abstract: Schematic diagram of Gd(III) adsorption and desorption on GO nanosheets in colloidal suspensions sealed by dialysis membrane. - Highlights: • Loading GO suspensions into dialysis bag for sorption of Gd(III) avoids re-pollution. • GO shows higher adsorption capacity for Gd(III) than any other currently reported. • Effects of pH, ionic strength and temperature on GO sorption for Gd(III) were studied. • Gd(III)-saturated GO has high desorption rate in nitric acid aqueous solution. • The thermodynamics and kinetics models of Gd(III) sorption on GO were studied. - Abstract: A facile, highly efficient and second-pollution-free strategy to remove trace Gd(III) from aqueous solutions by adsorption of colloidal graphene oxide (GO) suspensions in dialysis bag has been developed. The effects of pH, ionic strength and temperature on Gd(III) adsorption, and the pH-dependent desorption were investigated. The maximum adsorption capacity of Gd(III)on GO at pH = 5.9 ± 0.1 and T = 303 K was 286.86 mg g{sup −1}, higher than any other currently reported. The Gd(III)-saturated GO suspension could resume colloidal state in 0.1 M HNO{sub 3} with desorption rate of 85.00% in the fifth adsorption–desorption cycle. Gd(III) adsorption rate on GO was dependent more on pH and ionic strength than on temperature. The abundant oxygen-containing functional groups such as carboxyl and hydroxyl played a vital role on adsorption. The thermodynamics and kinetics investigations revealed that the adsorption of Gd(III) on GO was an endothermic, spontaneous and monolayer absorption process, which well fitted the pseudo-second-order model. GO could be a promising adsorbent applied in the enrichment and removal of lanthanides from aqueous solutions. More significantly, the combination of colloidal GO suspension with dialysis membrane facilely solves the re-pollution of the treated solutions due to the great difficulties in separation and recovery of GO.

  17. Aim High or Go Low? Pricing Strategies and Enrollment Effects when the Net Price Elasticity Varies with Need and Ability

    Science.gov (United States)

    Curs, Bradley R.; Singell, Larry D., Jr.

    2010-01-01

    Detailed data on individual applicants to a large public university are used to demonstrate that net price responsiveness decreases with need and ability. Enrollment effects are simulated and show a movement towards a high tuition/high aid (low tuition/low aid) policy significantly lowers (raises) tuition revenue with a modest increase (decrease)…

  18. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T.

    Science.gov (United States)

    Guo, Xiang; Zhou, Shan; Wang, Yanwei; Song, Jinlong; Wang, Huimin; Kong, Delong; Zhu, Jie; Dong, Weiwei; He, Mingxiong; Hu, Guoquan; Ruan, Zhiyong

    2016-01-01

    Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK) was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v) organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide) could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM) and Ethyl Violet (25 μM), respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions.

  19. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T

    Science.gov (United States)

    Guo, Xiang; Zhou, Shan; Wang, Yanwei; Song, Jinlong; Wang, Huimin; Kong, Delong; Zhu, Jie; Dong, Weiwei; He, Mingxiong; Hu, Guoquan; Ruan, Zhiyong

    2016-01-01

    Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK) was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v) organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide) could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM) and Ethyl Violet (25 μM), respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions. PMID:27741324

  20. Ag/AgBr/Co-Ni-NO3 layered double hydroxide nanocomposites with highly adsorptive and photocatalytic properties.

    Science.gov (United States)

    Fan, Hai; Zhu, Jianying; Sun, Jianchao; Zhang, Shenxiang; Ai, Shiyun

    2013-02-11

    A facile anion-exchange precipitation method was used to synthesize bifunctional Ag/AgBr/Co-Ni-NO(3) layered double hydroxide (LDH) nanocomposites by adding AgNO(3) solution to a suspension of Co-Ni-Br LDH. The Ag/AgBr nanoparticles were highly dispersed on the sheets of Co-Ni-NO(3) LDH. The prepared nanocomposites were used to adsorb and photocatalytically degrade organic pollutants from water. Without light illumination, the nanocomposites quickly adsorbed methyl orange, and the adsorptive capacity, which can reach 230 mg g(-1), is much higher than those of Co-Ni-Br LDH, Ag/AgBr, and activated carbon. The photocatalytic activities of the nanocomposites for the removal of dyes and phenol are higher than those of Co-Ni-Br LDH and Ag/AgBr. The proposed method can be applied to prepare other LDH/silver salt composites. The high absorptive capacity and good photocatalytic activity of such nanostructures could have wide applications in wastewater treatment.

  1. Developing E-Learning Based on Animation Content for Improving Mathematical Connection Abilities in High School Students

    Directory of Open Access Journals (Sweden)

    Dedi Rohendi

    2012-07-01

    Full Text Available The purpose of this paper is to develop e-learning based on animation content for improving mathematical connection abilities in senior high school students. The e-learning was developed by using Moddle and the animation content was developed by using macromedia flash. To get the student mathematical conection abilities it uses the instruments of mathematical tests before and after teaching and learning process. The data were analyzed by using t-test and gain value test. The study found that e-learning based on animation content not only had significant influence toward mathematical connection abilities but also able to improve students mathematical connection abilities far better than that of conventional approach.

  2. Do Peer Reviews Help Improve Student Writing Abilities in an EFL High School Classroom?

    Science.gov (United States)

    Kurihara, Noriko

    2017-01-01

    Several studies have reported the benefits of peer reviews in English as a second language (ESL) and English as a foreign language (EFL) writing classrooms. However, there has been little empirical research on whether such peer reviews improve students' writing abilities. The current study investigated the effects of peer review on the development…

  3. Postsecondary Students with High Abilities and Reading Disabilities: Case Analyses and Commentary

    Science.gov (United States)

    Mather, Nancy; Gerner, Michael E.

    2008-01-01

    Exceptionally bright and capable students with learning disabilities, often referred to as being twice exceptional, may fail to meet learning disabilities criteria if a strict psychometric approach is taken. To make an accurate diagnosis, an evaluator must consider their special circumstances, unique abilities, educational histories, and…

  4. Gifted, Talented and High Ability: Selection for Education in a One-Dimensional World

    Science.gov (United States)

    Tomlinson, Sally

    2008-01-01

    This article attempts to explain why it is that in England, despite twentieth-century moves towards egalitarianism in education, the selection and segregation of those regarded as being gifted, talented, or of higher ability in better resourced schools and programmes is now increasingly acceptable. Explanations for moves away from attempts to…

  5. The Importance of Intrinsic Motivation for High and Low Ability Readers' Reading Comprehension Performance

    Science.gov (United States)

    Logan, Sarah; Medford, Emma; Hughes, Naomi

    2011-01-01

    The study examined how cognitive and motivational factors predicted reading skill and whether intrinsic reading motivation would explain significantly more variance in low ability readers' reading performance. One hundred and eleven children (aged 9-11) completed assessments of reading comprehension skill, verbal IQ, decoding skill and intrinsic…

  6. Discussions about Students’Writing Ability Development in Senior High School

    Institute of Scientific and Technical Information of China (English)

    计金平

    2014-01-01

    With the growing communication with western countries,English especially English writing is becoming more and more important while in China, some English teachers still haven’t given enough emphasis on fostering students’writing ability. Here the author will discuss it and give some suggestions.

  7. Preferential adsorption of polycarboxylate superplasticizers on cement and silica fume in ultra-high performance concrete (UHPC)

    Energy Technology Data Exchange (ETDEWEB)

    Schroefl, Ch.; Gruber, M.; Plank, J., E-mail: sekretariat@bauchemie.ch.tum.de

    2012-11-15

    UHPC is fluidized particularly well when a blend of MPEG- and APEG-type PCEs is applied. Here, the mechanism for this behavior was investigated. Testing individual cement and micro silica pastes revealed that the MPEG-PCE disperses cement better than silica whereas the APEG-PCE fluidizes silica particularly well. This behavior is explained by preferential adsorption of APEG-PCE on silica while MPEG-PCEs exhibit a more balanced affinity to both cement and silica. Adsorption data obtained from individual cement and micro silica pastes were compared with those found for the fully formulated UHPC containing a cement/silica blend. In the UHPC formulation, both PCEs still exhibit preferential and selective adsorption similar as was observed for individual cement and silica pastes. Preferential adsorption of PCEs is explained by their different stereochemistry whereby the carboxylate groups have to match with the steric position of calcium ions/atoms situated at the surfaces of cement hydrates or silica.

  8. N2 and CO2 Adsorption by Soils with High Kaolinite Content from San Juan Amecac, Puebla, México

    Directory of Open Access Journals (Sweden)

    Karla Quiroz-Estrada

    2016-07-01

    Full Text Available Carbon dioxide (CO2 is considered one of the most important greenhouse gases in the study of climate change. CO2 adsorption was studied using the gas chromatography technique, while the Freundlich and Langmuir adsorption models were employed for processing isotherm data in the temperature range of 473–573 K. The isosteric heat of adsorption was calculated from the Clausius–Clapeyron equation. Moreover, the thermodynamic properties ΔG, ΔU, and ΔS were evaluated from the adsorption isotherms of Langmuir using the Van’t Hoff Equation. The four soil samples were recollected from San Juan Amecac, Puebla, Mexico, and their morphologies were investigated through X-ray diffraction (XRD and N2 adsorption at 77 K. The SJA4 soil has a crystalline Kaolinite phase, which is one of its non-metallic raw materials, and N2 isotherms allowed for the determination of pore size distributions and specific surface areas of soil samples. The Barrett–Joyner–Halenda (BJH distribution of pore diameters was bimodal with peaks at 1.04 and 3.7 nm, respectively. CO2 adsorption showed that the SJA1 soil afforded a higher amount of adsorbed CO2 in the temperature range from 453 to 573 K followed by SJA4 and finally SJA2, classifying this process as exothermic physisorption.

  9. Hierarchical flower-like nickel(II) oxide microspheres with high adsorption capacity of Congo red in water.

    Science.gov (United States)

    Zheng, Yingqiu; Zhu, Bicheng; Chen, Hua; You, Wei; Jiang, Chuanjia; Yu, Jiaguo

    2017-10-15

    Monodispersed hierarchical flower-like nickel(II) oxide (NiO) microspheres were fabricated by a facile solvothermal reaction with the assistance of ethanolamine and a subsequent calcination process. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption isotherms, zeta potential measurement and Fourier transform infrared spectroscopy. Flower-like nickel(II) hydroxide microspheres with uniform diameters of approximate 6.3μm were obtained after the solvothermal reaction. After heat treatment at 350°C, the crystal phase transformed to NiO, but the hierarchical porous structure was maintained. The as-prepared microspheres exhibited outstanding performance for the adsorption of Congo red (CR), an anionic organic dye, from aqueous solution at circumneutral pH. The pseudo-second-order model can make a good description of the adsorption kinetics, while Langmuir model could well express the adsorption isotherms, with calculated maximum CR adsorption capacity of 534.8 and 384.6mgg(-1), respectively, for NiO and Ni(OH)2. The adsorption mechanism of CR onto the as-synthesized samples can be mainly attributed to electrostatic interaction between the positively charged sample surface and the anionic CR molecules. The as-prepared NiO microspheres are a promising adsorbent for CR removal in water treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Edge-functionalized nanoporous carbons for high adsorption capacity and selectivity of CO2 over N2

    Science.gov (United States)

    Zhou, Sainan; Guo, Chen; Wu, Zhonghua; Wang, Maohuai; Wang, Zhaojie; Wei, Shuxian; Li, Shaoren; Lu, Xiaoqing

    2017-07-01

    Single-component adsorption and competitive behavior of binary CO2/N2 mixture in the edge-functionalized nanoporous carbons (NPCs) were investigated by grand canonical Monte Carlo simulation. Results demonstrated that edge-functionalization effectively improved the pore topology and morphological characteristics of NPCs. Evaluation of adsorption capacity and analyses of the isosteric heat and radial distribution functions confirmed that edge-functionalization can evidently enhance the single-component adsorption of CO2/N2. Temperature had a negative effect on the single-component adsorption of CO2/N2 whereas pressure had a positive effect before adsorption reaches a stable equilibrium state. Edge-functionalization can significantly increase the selectivity of CO2 over N2 in NPCs, which demonstrate the following sequence according to selectivity: NH2sbnd NPC > COOHsbnd NPC > OHsbnd NPC > Hsbnd NPC > NPC. The increased CO2 molar fraction in the binary CO2/N2 mixture decreased the selectivity and saturation pressure to reach a stable equilibrium state. Overall, this work highlighted the effects of edge-functionalization on the adsorption and separation of CO2/N2 in NPCs, and provided an effective strategy for designing and screening adsorbent materials for carbon capture and separation.

  11. Highly porous activated carbon based adsorption cooling system employing difluoromethane and a mixture of pentafluoroethane and difluoromethane

    Science.gov (United States)

    Askalany, Ahmed A.; Saha, Bidyut B.

    2017-01-01

    This paper presents a simulation for a low-grade thermally powered two-beds adsorption cooling system employing HFC-32 and a mixture of HFC-32 and HFC-125 (HFC-410a) with activated carbon of type Maxsorb III. The present simulation model adopts experimentally measured adsorption isotherms, adsorption kinetics and isosteric heat of adsorption data. Effect of operating conditions (mass flow rate of hot water, driving heat source temperature and evaporator temperature) on the system performance has been studied in detail. The simulation results showed that the system could be powered by low-grade heat source temperature (below 85 °C). AC/HFC-32 and AC/HFC-410a adsorption cooling cycles achieved close specific cooling power and coefficient of performance values of 0.15 kW/kg and 0.3, respectively at a regeneration temperature of 90 °C along with evaporator temperature of 10 °C. The investigated semi continuous adsorption cooling system could produce a cooling power of 9 kW.

  12. Highly Selective Water Adsorption in a Lanthanum Metal-Organic Framework

    NARCIS (Netherlands)

    Plessius, R.; Kromhout, R.; Dantas Ramos, A.L.; Ferbinteanu, M.; Mittelmeijer-Hazeleger, M.C.; Krishna, R.; Rothenberg, G.; Tanase, S.

    2014-01-01

    We present a new metal-organic framework (MOF) built from lanthanum and pyrazine-2,5-dicarboxylate (pyzdc) ions. This MOF, [La(pyzdc)(1.5)(H2O)(2)]center dot 2H(2)O, is microporous, with 1D channels that easily accommodate water molecules. Its framework is highly robust to dehydration/hydration

  13. Oxygen adsorption on Pt(110)-(1x2): new high-coverage structures

    DEFF Research Database (Denmark)

    Helveg, Stig; Lorensen, Henrik Qvist; Horch, Sebastian

    1999-01-01

    to the formation of a new high-coverage oxide-like structure with a local coverage of two oxygen atoms per platinum surface atom. We find that the repulsive O-O interactions for the O/Pt(110) system are compensated by an effective O-O attractive interaction originating from a strong coupling between oxygen...

  14. The effects of high-voltage pulse electric discharges on ion adsorption on activated carbons

    Science.gov (United States)

    Gafurov, M. M.; Sveshnikova, D. A.; Larin, S. V.; Rabadanov, K. Sh.; Shabanova, Z. E.; Yusupova, A. A.; Ramazanov, A. Sh.

    2008-07-01

    The effects of high-voltage pulse electric discharges (HPED) on sorption of boron and sulfate ions on activated carbons of different kinds (KM-2, BAU, DAK) were investigated. The effect of HPED activation on the sorption characteristics of the systems was found to be similar to the temperature effect.

  15. Adsorptive desulfurization of diesel with mesoporous aluminosilicates

    Institute of Scientific and Technical Information of China (English)

    TANG Huang; LI Wang-Liang; LIU Qing-Fen; GUAN Li-Li; SONG Jia-Qing; XING dian-Min; LIU Hui-Zhou

    2009-01-01

    Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MASMCM-41NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.

  16. A novel strategy for high-stability lithium sulfur batteries by in situ formation of polysulfide adsorptive-blocking layer

    Science.gov (United States)

    Jin, Liming; Li, Gaoran; Liu, Binhong; Li, Zhoupeng; Zheng, Junsheng; Zheng, Jim P.

    2017-07-01

    Lithium sulfur (Lisbnd S) batteries are one of the most promising energy storage devices owing to their high energy and power density. However, the shuttle effect as a key barrier hinders its practical application by resulting in low coulombic efficiency and poor cycling performance. Herein, a novel design of in situ formed polysulfide adsorptive-blocking layer (PAL) on the cathode surface was developed to tame the polysulfide shuttling and promote the cycling stability for Lisbnd S batteries. The PAL is consisted of La2S3, which is capable to chemically adsorb polysulfide via the strong interaction of Lasbnd S bond and Ssbnd S bond, and build an effective barrier against sulfur escaping. Moreover, the La2S3 is capable to suppress the crystallization of Li2S and promote the ion transfer, which contributes to the reduced internal resistance of batteries. Furthermore, the by-product LiNO3 simultaneously forms a stable anode solid and electrolyte interface to further inhibit the polysulfide shuttle. By this simple and convenient method, the resultant Lisbnd S batteries achieved exceptional cycling stability with an ultralow decay rate of 0.055% since the 10th cycle.

  17. Synthesis and high-efficiency methylene blue adsorption of magnetic PAA/MnFe2O4 nanocomposites

    Science.gov (United States)

    Wang, Wei; Ding, Zui; Cai, Minhan; Jian, Haitao; Zeng, Zhiqiao; Li, Feng; Liu, J. Ping

    2015-08-01

    MnFe2O4 nanoparticles and polyacrylic acid PAA/MnFe2O4 nanocomposites were synthesized by a hydrothermal method and ultrasonic mixing process. The obtained materials were characterized by XRD, FTIR, SEM, TEM, and VSM. XRD patterns indicate that the synthesized MnFe2O4 nanoparticles have a single cubic spinel phase. SEM images confirm the existence of three types of basic morphology of MnFe2O4 nanoparticles: octahedral, flower-like, and plate-like particles. High saturation magnetization Ms (up to 74.6 emu/g) of the as-synthesized MnFe2O4 nanoparticles was obtained. Experiments demonstrate that the variation of the hydrothermal reaction time does not remarkably affect the magnetic properties of MnFe2O4 nanoparticles. In PAA/MnFe2O4 nanocomposites, the coating of PAA leads to a slight decrease in magnetization of MnFe2O4 nanoparticles. Additionally, PAA coating greatly enhances the adsorption properties of MnFe2O4 nanoparticles for Methylene Blue (MB) dye. Especially, the removal efficiency reaches 96.3%. This research indicates that the as-synthesized PAA/MnFe2O4 nanocomposites exhibit excellent magnetic properties and can be taken as a promising adsorbent for removal of MB dye in industrial scale.

  18. High-performance liquid chromatography as a technique to determine protein adsorption onto hydrophilic/hydrophobic surfaces.

    Science.gov (United States)

    Huang, Tongtong; Anselme, Karine; Sarrailh, Segolene; Ponche, Arnaud

    2016-01-30

    The purpose of this study is to evaluate the potential of simple high performance liquid chromatography (HPLC) setup for quantification of adsorbed proteins on various type of plane substrates with limited area (hydrophobic (polydimethylsiloxane: PDMS) surfaces, kinetics of adsorption were determined and amounts of adsorbed bovine serum albumin, myoglobin and lysozyme were obtained: as expected for each protein, the amount adsorbed at the plateau on glass (between 0.15 μg/cm(2) and 0.4 μg/cm(2)) is lower than for hydrophobic PDMS surfaces (between 0.45 μg/cm(2) and 0.8 μg/cm(2)). These results were consistent with bicinchoninic acid protein determination. According to ICH guidelines, both Reversed Phase and Size Exclusion HPLC can be validated for quantification of adsorbed protein. However, we consider the size exclusion approach more interesting in this field because additional informations can be obtained for aggregative proteins. Indeed, monomer, dimer and oligomer of bovine serum albumin (BSA) were observed in the chromatogram. On increasing the temperature, we found a decrease of peak intensity of bovine serum albumin as well as the fraction of dimer and oligomer after contact with PDMS and glass surface. As the surface can act as a denaturation parameter, these informations can have a huge impact on the elucidation of the interfacial behavior of protein and in particular for aggregation processes in pharmaceutical applications.

  19. Equilibrium adsorption isotherm studies of Cu (II) and Co (II) in high concentration aqueous solutions on Ag-TiO2-modified kaolinite ceramic adsorbents

    Science.gov (United States)

    Ajenifuja, E.; Ajao, J. A.; Ajayi, E. O. B.

    2017-09-01

    Photocatalytic ceramic adsorbents were prepared from locally sourced kaolinite clay minerals for the removal of copper and cobalt ions from high concentration aqueous solutions. The minerals were treated with mild acid before modification using silver nanoparticles sources and titanium-oxide nanoparticles. Batch adsorption experiment was carried out on the targeted ions and the results were analyzed by Langmuir and Freundlich equation at different concentrations (100-1000 mg/l). As-received raw materials do not exhibit any adsorption capacity. However, the adsorption isotherms for modified kaolinite clay ceramic adsorbents could be fitted well by the Langmuir model for Cu2+ and Co2+ with correlation coefficient ( R) of up to 0.99705. The highest and lowest monolayer coverage ( q max) were 93.023 and 30.497 mg/g for Cu2+ and Co2+, respectively. The separation factor ( R L ) was less than one (ceramic adsorbent is favorable. The highest adsorbent adsorption capacity ( K f ) and intensity ( n) constants obtained from Freundlich model are 14.401 (Cu2+ on KLN-T) and 6.057 (Co2+ on KLN-T).

  20. The Effects of a Social and Talent Development Intervention for High Ability Youth with Social Skill Difficulties

    Science.gov (United States)

    Foley-Nicpon, Megan; Assouline, Susan G.; Kivlighan, D. Martin; Fosenburg, Staci; Cederberg, Charles; Nanji, Michelle

    2017-01-01

    Contemporary models highlight the need to cultivate cognitive and psychosocial factors in developing domain-specific talent. This model was the basis for the current study where high ability youth with self-reported social difficulties (n = 28, 12 with a coexisting disability) participated in a social skills and talent development intervention…

  1. Identifying High Ability Children with DSM-5 Autism Spectrum or Social Communication Disorder: Performance on Autism Diagnostic Instruments

    Science.gov (United States)

    Foley-Nicpon, Megan; Fosenburg, Staci L.; Wurster, Kristin G.; Assouline, Susan G.

    2017-01-01

    This study was a replication of Mazefsky et al.'s ("Journal of Autism and Developmental Disabilities" 43:1236-1242, 2013) investigation among a sample of 45 high ability children and adolescents diagnosed with ASD under DSM-IV-TR. Items from the ADOS and ADI-R were mapped onto DSM-5 diagnostic criteria for ASD and SCD to determine…

  2. Intellectual Ability, Self-Perceived Social Competence, and Depressive Symptomatology in Children with High-Functioning Autistic Spectrum Disorders

    Science.gov (United States)

    Vickerstaff, Sandy; Heriot, Sandra; Wong, Michelle; Lopes, Ana; Dossetor, David

    2007-01-01

    Although social competence deficits in children with high-functioning autistic spectrum disorders (HFASD) are well documented, there is little research investigating self-perceptions of social limitations. This study replicated research showing a negative association between self-perceived social competence and intellectual ability and…

  3. A Study of High School Music Participants' Stylistic Preferences and Identification Abilities in Music and the Visual Arts.

    Science.gov (United States)

    Haack, Paul

    1982-01-01

    Research investigated how high school students conceptualize the basic Classical-Romantic values dichotomy as exemplified by various aesthetic eras, styles, and objects, and how students operate within such aesthetic-conceptual frameworks in terms of their preferences and identification-categorization abilities. (Author/AM)

  4. The Intelligence of Observation: Improving High School Students' Spatial Ability by Means of Intervention Unit

    Science.gov (United States)

    Patkin, Dorit; Dayan, Ester

    2013-01-01

    This case study of one class versus a control group focused on the impact of an intervention unit, which is not part of the regular curriculum, on the improvement of spatial ability of high school students (forty-six 12th-graders, aged 17-18, both boys and girls) in general as well as from a gender perspective. The study explored three…

  5. Cultural and Social Capital and Talent Development: A Study of a High-Ability Aboriginal Student in a Remote Community

    Science.gov (United States)

    Kostenko, Karen; Merrotsy, Peter

    2009-01-01

    During the course of a school year, a study was conducted on the cultural context, the social milieu and the personal characteristics of a high ability Aboriginal student in a remote community in Canada. Using the lenses of cultural capital, social capital and human capital, the study explores the development of the student's talent through his…

  6. University Rankings in Action? The Importance of Rankings and an Excellence Competition for University Choice of High-Ability Students

    Science.gov (United States)

    Horstschraer, Julia

    2012-01-01

    This paper analyzes how high-ability students respond to different indicators of university quality when applying for a university. Are prospective students influenced by quality indicators of a university ranking or by an excellence status awarded within a nationwide competition? And if so, are some quality dimensions, e.g. research reputation,…

  7. Differences and similarities in double special educational needs: high abilities/giftedness x Asperger’s Syndrome

    Directory of Open Access Journals (Sweden)

    Nara Joyce Wellausen Vieira

    2012-08-01

    Full Text Available The study was developed from a literature search in books, articles and theses that have been published since the year 2000 on the theme High Abilities / Giftedness and Asperger’s Syndrome. The objectives of this research were to conduct a search on publications from 2000 to 2011, about the common and different features to the person with Asperger syndrome and high ability gifted, and also relate the number of publications found in Education and Special Education. At theoretical we present the conception of High Abilities / Giftedness of Renzulli (2004 and Gardner (2000 and in the conception of Asperger Syndrome, Mello (2007 and Klin (2006. When analyzing the data, were perceived similarities and differences between the behavioral characteristics of individuals with High Abilities / Giftedness and those with Asperger’s Syndrome. It’s possible point out that there is much evidence that separate these two special educational needs and few similarities between them. But do not neglect that there may be a dual disability between these two particular special educational needs, because there are still few studies that verify theoretically the differences and similarities of these subjects, much less those that investigate these similarities and distinctions in the subjects themselves.

  8. Identifying High Ability Children with DSM-5 Autism Spectrum or Social Communication Disorder: Performance on Autism Diagnostic Instruments

    Science.gov (United States)

    Foley-Nicpon, Megan; Fosenburg, Staci L.; Wurster, Kristin G.; Assouline, Susan G.

    2017-01-01

    This study was a replication of Mazefsky et al.'s ("Journal of Autism and Developmental Disabilities" 43:1236-1242, 2013) investigation among a sample of 45 high ability children and adolescents diagnosed with ASD under DSM-IV-TR. Items from the ADOS and ADI-R were mapped onto DSM-5 diagnostic criteria for ASD and SCD to determine…

  9. Fabrication of three-dimensional graphene foam with high electrical conductivity and large adsorption capability

    Science.gov (United States)

    Chen, Guiqiang; Liu, Yanxia; Liu, Fei; Zhang, Xiao

    2014-08-01

    A three-dimensional (3D), free-standing graphene foam was prepared by plasma-enhanced chemical vapor deposition on nickel-foam. The prepared graphene foam was found to consist of few-layered vertically-aligned graphene sheets with highly graphite structure. Owing to the 3D interconnected porous nanostructures, the graphene foam exhibited a high electrical conductivity of 125 S/cm and a large surface area of 625.4 cm2/g. For practical application, we prepared the graphene foam/epoxy composites showing a maximum conductivity of 196 S/m at 2.5 vol.% filler loading, and a rather low percolation threshold of 0.18 vol.%. Furthermore, the derived graphene oxide foam exhibited an excellent absorption capability (177.6 mg/g for As(V), 399.3 mg/g for Pb(II)) and recyclability (above 90% removal efficiency after five cycles) for the removal of heavy metal ions. The present study reveals that the multifunctional graphene foam may broaden the graphene-based materials for the applications in electrically conductive composites and environmental cleanup.

  10. Solubility and Surface Adsorption Characteristics of Metal Oxides to High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    D.J. Wesolowski; M.L. Machesky; S.E. Ziemniak; C. Xiao; D.A. Palmer; L.M. Anovitz; P. Benezeth

    2001-05-04

    The interaction of high temperature aqueous solutions with mineral surfaces plays a key role in many aspects of fossil, geothermal and nuclear energy production. This is an area of study in which the subsurface geochemical processes that determine brine composition, porosity and permeability changes, reservoir integrity, and fluid flow rates overlap with the industrial processes associated with corrosion of metal parts and deposition of solids in pipes and on heat exchanger surfaces. The sorption of ions on mineral surfaces is also of great interest in both the subsurface and ''above ground'' regimes of power production, playing a key role in subsurface migration of contaminants (nuclear waste disposal, geothermal brine re-injection, etc.) and in plant operations (corrosion mitigation, migration of radioactive metals from reactor core to heat exchanger, etc.). In this paper, results of the solubility and surface chemistry of metal oxides relevant to both regimes are summarized.

  11. Combination volumetric and gravimetric sorption instrument for high accuracy measurements of methane adsorption

    Science.gov (United States)

    Burress, Jacob; Bethea, Donald; Troub, Brandon

    2017-05-01

    The accurate measurement of adsorbed gas up to high pressures (˜100 bars) is critical for the development of new materials for adsorbed gas storage. The typical Sievert-type volumetric method introduces accumulating errors that can become large at maximum pressures. Alternatively, gravimetric methods employing microbalances require careful buoyancy corrections. In this paper, we present a combination gravimetric and volumetric system for methane sorption measurements on samples between ˜0.5 and 1 g. The gravimetric method described requires no buoyancy corrections. The tandem use of the gravimetric method allows for a check on the highest uncertainty volumetric measurements. The sources and proper calculation of uncertainties are discussed. Results from methane measurements on activated carbon MSC-30 and metal-organic framework HKUST-1 are compared across methods and within the literature.

  12. High work ability in the scientific activity of older and experienced academics.

    Science.gov (United States)

    Kristjuhan, Ulo; Taidre, Erika

    2012-01-01

    At present the health of people in theirs 60s is the same as in theirs 50s around fifty years ago. Using older academics is a topical problem for universities in remaining efficient. Data regarding academics' scientific productivity at universities were collected and questionnaires compiled in the Faculty of Economics and Business Administration of Tallinn University of Technology in Estonia. Studies showed that the productivity of academics at university increases as they grow older (into their 60s). These academics are valuable to the university. The choice of academics should be made according to the candidates' knowledge and ability to work.

  13. Supercritical CO2 Assisted Synthesis of EDTA-Fe3O4 Nanocomposite with High Adsorption Capacity for Hexavalent Chromium

    Directory of Open Access Journals (Sweden)

    Gunjan Bisht

    2016-01-01

    Full Text Available Efficiency of EDTA functionalized nanoparticles in adsorption of chromium (VI from water was investigated in this study. Magnetic iron oxide nanoparticles (IONPs were synthesized by a simple chemical coprecipitation route and EDTA coating onto IONPs was attained via supercritical carbon dioxide (Sc CO2, a technology with green sustainable properties. The obtained nanoparticles were then characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR, X-ray powder diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and vibrating magnetometric analysis (VSM. The synthesized nanoparticle and its modified variant were evaluated as adsorbent for chromium (VI removal from water through batch adsorption technique and the effect of analytic concentration; contact time and adsorbent concentration were studied at pH 2. The results showed higher removal efficiency for modified magnetic iron oxide nanoparticles (MIONPs (i.e., 99.9% than their nonmodified variant IONPs, that is, 34.06% for the same concentration after 18 hours of incubation. Also maximum adsorption capacity (qe = 452.26 mg/g of MIONPs attained can be related to their preparation in Sc CO2 as qe calculated from IONPs, that is, 170.33 mg/g, is lower than that of MIONPs. The adsorption data fit well with Freundlich isotherm equation while kinetic adsorption studies of chromium (VI were modeled by pseudo-second-order model.

  14. CONNECTION OF TURN AHEAD AND TURN BACK WITH MOTORIC ABILITIES OF THE FOURTH GRADE OF HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Jovica Petković

    2008-08-01

    Full Text Available The research is done for the purpose of determination and defining of the level of connection between some motoric abilities with success in realization of programmed contents from the area of gymnastics (turn ahead and turn back. The research is done on the sample of fifty students from the fourth grade of High School, on ten motoric tests and on two specific motoric assignments – turn ahead and turn back. The results of this research clearly point that there exist the multitude of statistically important coefficients of correlation between treated motoric abilities and applied motoric assignments.

  15. Comparing Diagnostic Ability of Basic Emotional States in Children with High Performance Autism Disorder with Normal Peers

    Directory of Open Access Journals (Sweden)

    Fatemeh Jalili

    2012-04-01

    Full Text Available Background: Study on weaknesses and diagnostic strategies of autistic children in social interactions as well as how we can diagnose different emotions in the face may be an efficient step towards their therapy and communication improvement. The objective of this study was to compare diagnostic ability of basic emotions in children with high-performance autism with normal peers.Materials and Method: In this comparative profile study, two groups of 16 individuals: children with high-performance autistic disorder and their normal peers were selected by available sample method in terms of age, sex and life location. Neuropsychology diagnostic test of different emotions in Benton face (changed version was used to determine diagnostic ability of emotions (happy, sad and angry. Statistical analysis was performed using SPSS software and descriptive statistics and t-test were done for both independent groups.Results: Results showed that the ability of both tested groups is equal in diagnosing emotional states of joy, anger and neutral condition in face while viewing face picture and there was not any significant difference between groups but in diagnosing emotional grief state, the performance of autistics is lower and there was significant difference with normal peer group.Conclusion: The autistic children with high function are equal in ability with normal children in case of recognizing the happiness, anger and neutral facial excitement. However, they are less competent in recognizing the sadness and facial excitement than normal children

  16. Investigation of cognitive abilities related to reading and spelling in Korean: readers with high, average, and low skill levels.

    Science.gov (United States)

    Park, Hyun-Rin; Uno, Akira

    2012-11-01

    In this study, we investigated the characteristics of cognitive abilities as predictors of Korean reading and spelling ability, and the characteristics of the cognition of reading difficulty in Korean. In 103 Korean third-grade children, we tested ability to read and spell, nonverbal intelligence, vocabulary size, phonological cognitive processing, visual cognitive processing, and naming speed. Our results indicated that receptive vocabulary, phoneme awareness, and naming speed served as factors for predicting reading test score; receptive vocabulary served as a factor for predicting spelling test score. We found that low reading-level groups had significantly slower performance on the naming speed task and lower scores on the receptive vocabulary test, as compared with the other groups (average and high reading-level groups). The present results have implications concerning useful tasks for screening for Korean poor readers. Copyright © 2012 John Wiley & Sons, Ltd.

  17. Gas adsorption and high-emission current induced degradation of field emission characteristics in solution-processed ZnO nanoneedles

    Science.gov (United States)

    Dardona, Sameh; Peles, Amra; Wrobel, Gregory; Piech, Martin; Gao, Pu-Xian

    2010-12-01

    The effects of gas adsorption and high current on the field emission characteristics of ZnO nanoneedles grown directly from metal electrodes have been systematically investigated. Exposure of nanoneedles to H2, N2, or O2 gas degraded the field emission characteristics, with O2 having the strongest impact. Complete recovery of emission current following H2 and N2 treatment was accomplished by vacuum annealing at 450 °C. Meanwhile, changes induced by O2 adsorption were irreversible. First-principle calculations revealed electronic structure modifications through change of work function and charge density distribution upon gas exposure. It is suggested that the emission current degradation originates from shifts in the Fermi level caused by charge transfer from nanoneedle surface to gas adsorbates. Moreover, field emission degradation has been observed at high currents as a result of surface melting at the nanoneedles apex caused by resistive heating.

  18. Technical ability of new MTR high-density fuel alloys regarding the whole fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Durand, J.P. [CERCA, Romans (France); Maugard, B. [CEA, F-75000 Paris (France); Gay, A. [Cogema, Velizy (France)

    1998-07-01

    The development of new fuel alloys could provide a good opportunity to improve drastically the fuel cycle on the neutronic performances and the reprocessing point of view. Nevertheless, those parameters can only be considered if the fuel manufacture feasibility has been previously demonstrated. As a matter of fact, a MTR work group involving French partners (CEA, CERCA, COGEMA) has been set up in order to evaluate the technical ability of new fuels considering the whole fuel cycle. In this paper CERCA is presenting the preliminary results of UMo and UNbZr fuel plate manufacture, CEA is comparing to U{sub 3}Si{sub 2} the neutronic performances of fuels such as UMo, UN, UNbZr, while COGEMA is dealing with the reprocessing feasibility. (author)

  19. Condensate water treatment by adsorption onto an activated carbon grade with high-activity and low-silicate leaching

    Energy Technology Data Exchange (ETDEWEB)

    Herzer, J. [NORIT Germany, Kempen (Germany); Ernhofer, R. [BAYERNOIL Refineries, Ingolstadt (Germany); Dikkenberg, J. van den [NORIT Activated Carbon, Amersfoort (Netherlands)

    2006-07-01

    Granular activated carbon (GAC) is frequently used to remove dissolved organic impurities from condensate water. An optimal adsorption capacity and GAC life time are achieved by matching the size of the target organics versus the pore size distribution of the activated carbon. From a product range of over 150 activated carbon grades, eight different NORIT GAC types are available for condensate water polishing. Differences between these grades apply to adsorption properties, hydraulic properties and purity. Guidelines for design and operation of the GAC stage are provided. (orig.)

  20. Are Students with High Ability in Math More Motivated in Math and Science than Other Students?

    Science.gov (United States)

    Andersen, Lori; Cross, Tracy L.

    2014-01-01

    Expectancy-value motivation profiles were identified in a sample of US ninth-grade students in 2009 (n = 19,259) using latent profile analysis. Of four distinct profiles, two were high, one typical, and one low in math and in science. In each area, the two high profiles were distinguished by (1) high self-efficacy with lower utility value and (2)…

  1. Water adsorption on goethite: Application of multilayer adsorption models

    Science.gov (United States)

    Hatch, C. D.; Tumminello, R.; Meredith, R.

    2016-12-01

    Adsorbed water on the surface of atmospheric mineral dust has recently been shown to significantly affect the ability of mineral dust aerosol to act as cloud condensation nuclei. We have studied water adsorption as a function of relative humidity (RH) on goethite (α-FeO(OH)), a common component of atmospheric mineral dust. The goethite surface area and particle size was determined using BET analysis and with N2 as an adsorbate and scanning electron microscopy, respectively. Water adsorption on the sample was monitored using horizontal attenuated total reflectance Fourier transform infrared (HATR-FTIR) spectroscopy equipped with a flow cell. Water content was determined using Beer's law and the optical constants for bulk water. The results were analyzed using Type II adsorption isotherms to model multilayer adsorption, including BET (Brunauer, Emmet and Teller), FHH (Frenkel, Halsey and Hill) and Freundlich. BET fits to experimental data provide parameters of monolayer coverage, while the FHH and Freundlich isotherms provide insights into multilayer adsorption mechanisms. Results indicate that goethite contains 5% H2O by mass at 50% RH, which increases to 12% by mass at 90% RH. Adsorption parameters and experimental results will be presented.

  2. High-index-contrast grating reflector with beam steering ability for the transmitted beam

    DEFF Research Database (Denmark)

    Carletti, Luca; Malureanu, Radu; Mørk, Jesper

    2011-01-01

    High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derived...

  3. Failing Our Brightest Kids: The Global Challenge of Educating High-Ability Students. Educational Innovations Series

    Science.gov (United States)

    Finn, Chester E., Jr.; Wright, Brandon L.

    2015-01-01

    In this provocative volume, Chester E. Finn, Jr., and Brandon L. Wright argue that, for decades, the United States has done too little to focus on educating students to achieve at high levels. The authors identify two core problems: First, compared to other countries, the United States does not produce enough high achievers. Second, students from…

  4. Effects of textural and surface characteristics of microporous activated carbons on the methane adsorption capacity at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bastos-Neto, M. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Canabrava, D.V. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Torres, A.E.B. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Rodriguez-Castellon, E. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Malaga, 29071 Malaga (Spain); Jimenez-Lopez, A. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Malaga, 29071 Malaga (Spain); Azevedo, D.C.S. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil)]. E-mail: diana@gpsa.ufc.br; Cavalcante, C.L. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil)

    2007-04-30

    The objective of this study is to relate textural and surface characteristics of selected microporous activated carbons to their methane storage capacity. In this work, a magnetic suspension balance (Rubotherm, Germany) was used to measure methane adsorption isotherms of several activated carbon samples. Textural characteristics were assessed by nitrogen adsorption on a regular surface area analyzer (Autosorb-MP, by Quantachrome, USA). N{sub 2} adsorption was analysed by conventional models (BET, DR, HK) and by Monte Carlo molecular simulations. Elemental and surface analyses were performed by X-ray photoelectronic spectroscopy (XPS) for the selected samples. A comparative analysis was then carried out with the purpose of defining some correlation among the variables under study. For the system under study, pore size distribution and micropore volume seem to be a determining factor as long as the solid surface is perfectly hydrophobic. It was concluded that the textural parameters per se do not unequivocally determine natural gas storage capacities. Surface chemistry and methane adsorption equilibria must be taken into account in the decision-making process of choosing an adsorbent for gas storage.

  5. EFFECTS OF CARBOXYLIC ACIDS ON LIQUID-PHASE ADSORPTION OF ETHANOL AND WATER BY HIGH-SILICA ZSM-5

    Science.gov (United States)

    Adsorption isotherms were measured for each compound adsorbed on commercially available ZSM-5 (Si/Al = 140) powder from binary and ternary liquid mixtures of ethanol, carboxylic acids, and water at room temperature. The amounts adsorbed were measured using a recently developed t...

  6. Copper-based coordination polymers from thiophene and furan dicarboxylates with high isosteric heats of hydrogen adsorption

    NARCIS (Netherlands)

    Yang, J.; Lutz, M.; Grzech, A.; Mulder, F.M.; Dingemans, T.J.*

    2014-01-01

    Self-assembled Cu-based coordination polymers derived from thiophene-2,5-dicarboxylic acid (Cu-TDC) and furan-2,5-dicarboxylic acid (Cu-FDC) were synthesized via a solvothermal method and their H2 adsorption behaviour was investigated and contrasted with isophthalic acid (Cu-m-BDC) and terephthalic

  7. High performance NiFe layered double hydroxide for methyl orange dye and Cr(VI) adsorption.

    Science.gov (United States)

    Lu, Yi; Jiang, Bin; Fang, Liang; Ling, Faling; Gao, Jiemei; Wu, Fang; Zhang, Xihua

    2016-06-01

    The NiFe layered double hydroxides (LDHs) with different mole ratio of Ni/Fe (4:1, 3:1, 7:3 and 1:1) were prepared by a simple coprecipitation method. The adsorption performance were evaluated by the removal of methyl orange (MO) dye and hexavalent chromium(VI) heavy metal ion. It is found that Ni4Fe1-LDH can remove more than 92% of MO in 10 min at the 10 mg/L MO initial concentration, and 97% of Cr(VI) in 1 h at 4 mg/L Cr2O7(2-) initial concentration. The saturated adsorption capacity of Ni4Fe1-LDH is found to be as large as 205.76 mg/g for MO and 26.78 mg/g for Cr(VI). The adsorption behavior of this new adsorbent is fitted well with Langmuir isotherm and the pseudo-second-order kinetic model, indicative of a monolayer and chemical adsorption that synergistically originates from exchangeable anions mechanism and layer charge density. Due to the excellent removal capacity of MO and Cr(VI), the NiFe-LDHs could be a promising adsorbent for wastewater treatment.

  8. A study of perceptual analysis in a high-level autistic subject with exceptional graphic abilities.

    Science.gov (United States)

    Mottron, L; Belleville, S

    1993-11-01

    We report here the case study of a patient (E.C.) with an Asperger syndrome, or autism with quasinormal intelligence, who shows an outstanding ability for three-dimensional drawing of inanimate objects (savant syndrome). An assessment of the subsystems proposed in recent models of object recognition evidenced intact perceptual analysis and identification. The initial (or primal sketch), viewer-centered (or 2-1/2-D), or object-centered (3-D) representations and the recognition and name levels were functional. In contrast, E.C.'s pattern of performance in three different types of tasks converge to suggest an anomaly in the hierarchical organization of the local and global parts of a figure: a local interference effect in incongruent hierarchical visual stimuli, a deficit in relating local parts to global form information in impossible figures, and an absence of feature-grouping in graphic recall. The results are discussed in relation to normal visual perception and to current accounts of the savant syndrome in autism.

  9. High Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS): Pilot Knowledge, Skills and Abilities

    Science.gov (United States)

    2005-01-01

    This report summarizes the initial work accomplished by the ACCESS 5 Human System Integration (HSI) team to identify Unmanned Aircraft System (UAS) Pilot Knowledge, Skill and Ability (KSA), Training and Medical requirements. To derive this information the following tasks were accomplished: a) Mission and Function analyses were performed; b) Applicable FARs and FAA Advisory Circulars (ACs) were reviewed; c) Meetings were conducted with NASA and FAA Human Factors personnel; d) Surveys were completed by ACCESS 5 HSI Working group UA Pilots; e) Coordination meetings were conducted with the ACCESS 5 Policy IPT. The results of these efforts were used to develop a summary of the current qualifications. for an individual to function as a Pilot In Command (PIC) for UAs currently flown by UNITE companies, to develop preliminary Pilot KSAs for each phase of flight, and to delineate preliminary Pilot Training and Medical requirements. These results are to be provided to the Policy IPT to support their development of recommendations for UA Pilot Rating Criteria, training and medical qualifications. It is expected that the initially an instrument rated pilot will be required to serve as the PIC. However, as operational experience is gained, and automation is applied to accomplish various system functions, it is expected that pilot rating criteria could be lessened.

  10. Synthesis of magnetic ZnO/ZnFe2O4 by a microwave combustion method, and its high rate of adsorption of methylene blue.

    Science.gov (United States)

    Feng, Jing; Wang, Yuting; Zou, Linyi; Li, Bowen; He, Xiaofeng; Ren, Yueming; Lv, Yanzhuo; Fan, Zhuangjun

    2015-01-15

    The magnetic ZnO/ZnFe2O4 particles have been synthesized by a microwave combustion method using NaAc as fuel. The as-obtained ZnO/ZnFe2O4 was characterized and applied for the removal of methylene blue (MB) from aqueous solution in the batch system. The ZnO/ZnFe2O4 particles display larger S(BET) and smaller size with increase of NaAc dosage. Because a certain amount of gas is generated during NaAc decomposing and the gas prevent the particles from growing larger. More interestingly, even at neutral pH value, the ZnO/ZnFe2O4 obtained with 24 mL NaAc shows high-rate adsorption properties with the MB removal efficiency up to 90% in 0.5 min and a maximum adsorption capacity of 37.27 mg/g.

  11. A new simple tubular flow cell for use with variable angle spectroscopic ellipsometry: A high throughput in situ protein adsorption study

    Science.gov (United States)

    Byrne, T. M.; Trussler, S.; McArthur, M. A.; Lohstreter, L. B.; Bai, Zhijun; Filiaggi, M. J.; Dahn, J. R.

    2009-09-01

    A simple and novel flow cell design is presented here for use with variable angle spectroscopic ellipsometry (VASE) to study the adsorption of liquid-borne species on reflective surfaces. The flow cell allows a sample as large as 6 mm × 75 mm to be probed point by point and at any common ellipsometric angle of incidence, unlike other designs. Using our flow cell system with VASE, combinatorial films of Al 1-xNb x, Al 1-xTa x, and Al 1-xTi x (0 ⩽ x ⩽ 1) were tested in situ for fibrinogen affinity along their 75 mm long compositional gradients. Fibrinogen adsorption on the films was found to be closely correlated to the various surface oxide fractions, with high alumina content at the surface leading to low amounts of adsorbed fibrinogen for each binary library. Adsorbed amounts measured in situ were in agreement with previously obtained values found using ex situ techniques.

  12. Teachers think differently: Method effects on the evaluation of high intellectual ability students’ socio–emotional intelligence

    Directory of Open Access Journals (Sweden)

    Daniel Hernández

    2011-10-01

    Full Text Available This paper investigates the relationship between 566 students’, their parents’ and their teachers’ perceptions on the socio–emotional competence of such sample of learners with high intellectual abilities. The results indicated that parents’ and their children’s self-perceptions were positively related, the relationship being moderately statistically significant in all socio–emotional intelligence aspects. However, the relationship between teachers’ ratings and parents’ and students’ ratings was positively statistically significant at a low level. Using a multitrait–multimethod analysis (Campbell and Fiske, 1959, the authors demonstrated strong method effects, especially in the case of teachers, indicating that ratings from different sources provide different and complementary information on the socio–emotional skills of high intellectual ability students.

  13. Synthesis of PGMA Microspheres with Amino Groups for High-capacity Adsorption of Cr(VI) by Cerium Initiated Graft Polymerizatio

    Institute of Scientific and Technical Information of China (English)

    李鹏飞; 杨良嵘; 何秀琼; 王娟; 孔鹏; 邢慧芳; 刘会洲

    2012-01-01

    Abstract A novel polyglycidylmethacrylate (PGMA) microspheres with high adsorption capacity of Cr(VI) was prepared by cerium(IV) initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups. The micron-sized PGMA microspheres were prepared by a dispersion polym erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups. The polymer microspheres were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicated that the polymer microspheres had an average diameter of 5 m with uniform size distribution. The free amino group content was determined to be 5.13 mmol·g^-1 for g;PGMA-NH2 microspheres by potentiometric and conductometric titration methods. The Cr(VI) adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity (500 mg-g-l). The polymer microspheres with grafted tentacle polymer chains have potenial application in large-scale removal of Cr(VI) in aqueous solution.

  14. THE STUDIES ON CHELATING FIBER V.ADSORPTION BEHAVIOR OF Au3+ ONTO CHELATING FIBER CONTAINING AMIDOXIME GROUPS

    Institute of Scientific and Technical Information of China (English)

    LINWeiping; LUYun; 等

    1992-01-01

    The adsorption behavior of ionic gold onto chelating fiber containing amidoxime groups was investigated. The chelating fiber presents high adsorption capacity for ionic gold Au3+(up to 626mg/g,when the content of amidoxime group reaches 7.59mmol/g),and possesses the ability to reduce the Au3+ into metallic gold,In the redox process,the amidoxime group is oxidized into carboxyl group.

  15. High-index-contrast grating reflector with beam steering ability for the transmitted beam.

    Science.gov (United States)

    Carletti, Luca; Malureanu, Radu; Mørk, Jesper; Chung, Il-Sug

    2011-11-07

    High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derived. Such grating mirrors would have a significant impact on low cost laser fabrication, since a more efficient integration of optoelectronic modules can be achieved by avoiding expensive external lens systems.

  16. Exploring the Dimensions of Problem-solving Ability on High-achieving Secondary Students: A Mixed Methods Study

    OpenAIRE

    Hamm, Jolene Diane

    2010-01-01

    This mixed-methods study investigated the relationship between self-concept and problem-solving style and how these two constructs compared and contrasted in regards to a participantâ s perception of his or her problem-solving ability. The 86 study participants were high-achieving rising 11th and 12th grade students attending a summer enrichment program for agriculture. This study used a concurrent triangulation mixed methods design. The quantitative aspect of the study employed two instrum...

  17. High-Gravity Brewing: Effects of Nutrition on Yeast Composition, Fermentative Ability, and Alcohol Production

    OpenAIRE

    Casey, Gregory P.; Magnus, Carol A.; Ingledew, W M

    1984-01-01

    A number of economic and product quality advantages exist in brewing when high-gravity worts of 16 to 18% dissolved solids are fermented. Above this level, production problems such as slow or stuck fermentations and poor yeast viability occur. Ethanol toxicity has been cited as the main cause, as brewers' yeasts are reported to tolerate only 7 to 9% (vol/vol) ethanol. The inhibitory effect of high osmotic pressure has also been implicated. In this report, it is demonstrated that the factor li...

  18. The ability of Typha domingensis to accumulate and tolerate high concentrations of Cr, Ni, and Zn.

    Science.gov (United States)

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2015-01-01

    The tolerance and removal efficiency of Typha domingensis exposed to high concentrations of Cr, Ni, and Zn in single and combined treatments were studied. Sediment and two plants were disposed in each plastic reactor. The treatments were 100 and 500 mg L(-1) of Cr, Ni, and Zn (single solutions); 100 mg L(-1) Cr + Ni + Zn (multi-metal solutions) and 500 mg L(-1) Cr + Ni + Zn (multi-metal solutions); and a control. Even though the concentrations studied were extremely high, simulating an accidental metal dump, the three metals were efficiently removed from water. The highest removal was registered for Cr. The presence of other metals favored Cr and did not favor Ni and Zn removal from water. After 25 days, senescence and chlorosis of plants were observed in Ni and Comb500 treatments, while Cr and Zn only caused growth inhibition. T. domingensis accumulated high metal concentrations in tissues. The roots showed higher metal concentration than submerged parts of leaves. Cr translocation to aerial parts was enhanced by the presence of Ni and Zn. Our results demonstrate that in the case of an accidental dump of high Cr, Ni, and Zn concentrations, a wetland system dominated by T. domingensis is able to retain metals, and the macrophyte is able to tolerate them the time necessary to remove them from water. Thus, the environment will be preserved since the wetland would act as a cushion.

  19. High-gravity brewing: effects of nutrition on yeast composition, fermentative ability, and alcohol production.

    Science.gov (United States)

    Casey, G P; Magnus, C A; Ingledew, W M

    1984-09-01

    A number of economic and product quality advantages exist in brewing when high-gravity worts of 16 to 18% dissolved solids are fermented. Above this level, production problems such as slow or stuck fermentations and poor yeast viability occur. Ethanol toxicity has been cited as the main cause, as brewers' yeasts are reported to tolerate only 7 to 9% (vol/vol) ethanol. The inhibitory effect of high osmotic pressure has also been implicated. In this report, it is demonstrated that the factor limiting the production of high levels of ethanol by brewing yeasts is actually a nutritional deficiency. When a nitrogen source, ergosterol, and oleic acid are added to worts up to 31% dissolved solids, it is possible to produce beers up to 16.2% (vol/vol) ethanol. Yeast viability remains high, and the yeasts can be repitched at least five times. Supplementation does not increase the fermentative tolerance of the yeasts to ethanol but increases the length and level of new yeast cell mass synthesis over that seen in unsupplemented wort (and therefore the period of more rapid wort attenuation). Glycogen, protein, and sterol levels in yeasts were examined, as was the importance of pitching rate, temperature, and degree of anaerobiosis. The ethanol tolerance of brewers' yeast is suggested to be no different than that of sake or distillers' yeast.

  20. The Political Economy of Teacher Training: Attracting High-Ability Persons into Teaching--A Critique.

    Science.gov (United States)

    Sears, James T.; And Others

    1989-01-01

    The metaphor of securities investments is applied to a critical analysis of an experimental program designed to recruit, train, and retain bright high school students as teachers. Data from a longitudinal study of the Brindenthal Internship in Teaching Program forms the basis for the analysis. (IAH)

  1. Metalogue: A Multiperspective Multimodal Dialogue System with Metacognitive Abilities for Highly Adaptive and Flexible Dialogue Management

    NARCIS (Netherlands)

    Alexandersson, Jan; Aretoulaki, Maria; Campbell, Nick; Gardner, Michael; Girenko, Andrey; Klakow, Dietrich; Koryzis, Dimitris; Petukhova, Volha; Specht, Marcus; Spiliotopoulos, Dimitris; Stricker, Alexander; Taatgen, Niels

    2014-01-01

    This poster paper presents a high-level description of the Metalogue project that is developing a multi-modal dialogue system that is able to implement interactive behaviors that seem natural to users and is flexible enough to exploit the full potential of multimodal interaction. We provide an outli

  2. Adsorption Rate Models for Multicomponent Adsorption Systems

    Institute of Scientific and Technical Information of China (English)

    姚春才

    2004-01-01

    Three adsorption rate models are derived for multicomponent adsorption systems under either pore diffusion or surface diffusion control. The linear driving force (LDF) model is obtained by assuming a parabolic intraparticle concentration profile. Models I and Ⅱ are obtained from the parabolic concentration layer approximation. Examples are presented to demonstrate the usage and accuracy of these models. It is shown that Model I is suitable for batch adsorption calculations and Model Ⅱ provides a good approximation in fixed-bed adsorption processes while the LDF model should not be used in batch adsorption and may be considered acceptable in fixed-bed adsorption where the parameter Ti is relatively large.

  3. Rorschach interpretation with high-ability adolescent females: psychopathology or creative thinking?

    Science.gov (United States)

    Franklin, K W; Cornell, D G

    1997-02-01

    Highly intelligent and creative persons have long posed interpretation difficulties for users of the Rorschach Inkblot Test. This study examined Exner's (1993) Schizophrenia, Depression, and Coping Deficit indices as adjustment measures in a sample of 43 female adolescents enrolled in an early college entrance program and a comparison group of 19 girls enrolled in public high school gifted programs. Contrary to conventional interpretation, higher scores on the Rorschach Schizophrenia Index among the accelerants were correlated with healthy emotional adjustment on both the California Psychological Inventory and the Self-Perception Profile for Adolescents (SPPA). Further analyses offered support for the hypothesis that among accelerants, elevated scores on the Rorschach constellations did not indicate psychopathology, but rather their creative thinking style.

  4. High embryogenic ability and regeneration from floral axis of Amorphophallus konjac (Araceae)

    OpenAIRE

    Zhong Lin; Liu Erxi; Yang Chaozhu; Jin Surong; Diao Ying; Hu Zhongli

    2017-01-01

    Amorphophallus konjac (Araceae) a perennial herb, it has high medicinal and industrial value. In this study, a simple and efficient system for direct somatic embryogenesis and plantlet regeneration of Amorphophallus konjac was developed. The floral axis was used as the experimental material. The primary callus, developed from the floral axis grown on Murashige and Skoog (MS) medium supplemented with different hormone combination at different concentrations. The highest rate of embryogenic cal...

  5. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  6. A Partially Fluorinated, Water-Stable Cu(II)-MOF Derived via Transmetalation: Significant Gas Adsorption with High CO2 Selectivity and Catalysis of Biginelli Reactions.

    Science.gov (United States)

    Pal, Tapan K; De, Dinesh; Senthilkumar, S; Neogi, Subhadip; Bharadwaj, Parimal K

    2016-08-15

    A partially fluorinated, angular tetracarboxylic acid linker (H4L) incorporating a pendant amine moiety forms a three-dimensional Zn(II) framework, 1. The structure consists of paddle-wheel Zn2(CO2)4 secondary building units (SBUs) and Zn12(CO2)24 supramolecular building blocks (SBBs). Thermal stability of 1 is found to be low. However, it undergoes transmetalation reaction with Cu(II) at room temperature without losing crystallinity affording an isostructural framework, 1Cu. Framework 1Cu is thermally robust and allows generation of the solvent-free porous framework 1Cu' upon activation with coordinatively unsaturated metal centers. Framework 1Cu' exhibits water stability and at 77 K, adsorbs 2.56 wt % of H2 up to 1 bar that significantly increases to 4.01 wt % at 13 bar. Also, this framework gives a high adsorption of 164.70 cc/g of CH4 (11.7 wt %) at 303 K and 60 bar. The channel surfaces decorated with -NH2 group and unsaturated metal centers in 1Cu' allow a promising 36.4 wt % of CO2 adsorption at 1 bar and 273 K. Moreover, it exhibits pronounced selectivity of CO2 adsorption over N2 and H2 at 273 K. Finally, the versatility of 1Cu' is shown by its excellent heterogeneous catalytic activity in the Biginelli coupling reactions involving an aldehyde, urea, and ethylacetoacetate to afford dihydroprimidinones.

  7. XDA-8大孔树脂对高浓度咖啡因的吸附热力学研究%Thermodynamics Study on Adsorption of High-Concentration Caffeine by Macroporous Resin XDA-8

    Institute of Scientific and Technical Information of China (English)

    孙培宾; 陈江; 尹进华; 陈学玺

    2011-01-01

    Adsorption isotherms of high-concentration caffeine on polar macroporous adsorptive resin XDA8 were determined at different temperature, which was fit by Langmuir isothermal adsorption equation, and then the thermodynamics study on the adsorption behavior was conducted. The results showed that, Langmuir adsorption isothermal equation fitted the adsorption process well and caffeine was adsorbed on single layer of the resin;the process was exothermic, and higher temperature was disadvantage to the adsorption; the adsorption process was spontaneous; the motion of cafein was restricted after adsorption, and the restriction got stronger when the adsorption capacity increased.%测定了不同温度下极性大孔吸附树脂XDA-8对高浓度咖啡因的吸附等温线,并采用Langmuir吸附等温方程进行了拟合,在此基础上对吸附行为进行了热力学研究.结果表明,Langmuir吸附等温方程对吸附过程拟合程度很高,XDA-8大孔树脂对咖啡因的吸附为单分子层吸附;XDA-8大孔树脂吸附咖啡因是一个放热过程,升高温度使其吸附能力下降;吸附是自发进行的;吸附质分子被吸附后其运动受到限制,且吸附量越大,限制越大.为树脂在工业咖啡因废水处理中的应用提供了理论依据.

  8. Short Circuits or Superconductors? Examining Factors That Encourage or Undermine Group Learning and Collaboration among High-Ability Students. CSE Technical Report.

    Science.gov (United States)

    Webb, Noreen M.; Welner, Mari; Zuniga, Stephen

    This study investigated the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high ability students completing science performance assessments. Participants were 99 seventh and eighth graders from 9 classes in 2 schools. The results show that group ability composition does not have…

  9. The component fractionation effect in binary-component gas adsorption isotherm experiments on coal

    Institute of Scientific and Technical Information of China (English)

    TANG Shuheng; HAO Duohu; TANG Dazhen; LIU Dameng

    2005-01-01

    Different gas adsorption isotherm experiments were carried out on the coal samples from Jincheng district,including N2, CH4, CO2, as well as the binary-component gas of CH4-N2 and CH4-CO2 of three different concentrations. In the binary-component gas adsorption isotherm experiments,the gas component with higher adsorption ability is adsorbed firstly. Thus the result in its relative concentration in the free phase shows a trend of decrease first and then increase,whereas the relative concentration of the gas component with lower adsorption ability shows a trend of increase first and then decrease. In the adsorption phrase, the relative concentration of the gas component with higher adsorption ability increases gradually, and the relative concentration of the gas component with lower adsorption ability decreases gradually.In the adsorption competition of the binary-component gas,the adsorption rate of the gas component with higher adsorption ability shows a trend of rapidity at first then slowness, but the adsorption rate of the gas component with lower adsorption ability shows a trend of slowness at first then rapidity. The component fractionation effect in the binary-component gas adsorption isotherm experiments is caused by the difference of the adsorption ability of coal of different gas components.

  10. High phosphate reduces host ability to develop arbuscular mycorrhizal symbiosis without affecting root calcium spiking responses to the fungus

    Directory of Open Access Journals (Sweden)

    Coline eBalzergue

    2013-10-01

    Full Text Available The arbuscular mycorrhizal symbiosis associates soil fungi with the roots of the majority of plants species and represents a major source of soil phosphorus acquisition. Mycorrhizal interactions begin with an exchange of molecular signals between the two partners. A root signaling pathway is recruited, for which the perception of fungal signals triggers oscillations of intracellular calcium concentration. High phosphate availability is known to inhibit the establishment and/or persistence of this symbiosis, thereby favoring the direct, non symbiotic uptake of phosphorus by the root system. In this study, Medicago truncatula plants were used to investigate the effects of phosphate supply on the early stages of the interaction. When plants were supplied with high phosphate fungal attachment to the roots was drastically reduced. An experimental system was designed to individually study the effects of phosphate supply on the fungus, on the roots and on root exudates. These experiments revealed that the most important effects of high phosphate supply were on the roots themselves, which became unable to host mycorrhizal fungi even when these had been appropriately stimulated. The ability of the roots to perceive their fungal partner was then investigated by monitoring nuclear calcium spiking in response to fungal signals. This response did not appear to be affected by high phosphate supply. In conclusion, high levels of phosphate predominantly impact the plant host, but apparently not in its ability to perceive the fungal partner.

  11. Cancer-associated fibroblasts from lung tumors maintain their immunosuppressive abilities after high-dose irradiation.

    Science.gov (United States)

    Gorchs, Laia; Hellevik, Turid; Bruun, Jack-Ansgar; Camilio, Ketil-Andre; Al-Saad, Samer; Stuge, Tor-Brynjar; Martinez-Zubiaurre, Inigo

    2015-01-01

    Accumulating evidence supports the notion that high-dose (>5 Gy) radiotherapy (RT) regimens are triggering stronger pro-immunogenic effects than standard low-dose (2 Gy) regimens. However, the effects of RT on certain immunoregulatory elements in tumors remain unexplored. In this study, we have investigated the effects of high-dose radiotherapy (HD-RT) on the immunomodulating functions of cancer-associated fibroblasts (CAFs). Primary CAF cultures were established from lung cancer specimens derived from patients diagnosed for non-small cell lung cancer. Irradiated and non-irradiated CAFs were examined for immunomodulation in experiments with peripheral blood mononuclear cells from random, healthy donors. Regulation of lymphocytes behavior was checked by lymphocyte proliferation assays, lymphocyte migration assays, and T-cell cytokine production. Additionally, CAF-secreted immunoregulatory factors were studied by multiplex protein arrays, ELISAs, and by LC-MS/MS proteomics. In all functional assays, we observed a powerful immunosuppressive effect exerted by CAF-conditioned medium on activated T-cells (p > 0.001), and this effect was sustained after a single radiation dose of 18 Gy. Relevant immunosuppressive molecules such as prostaglandin E2, interleukin-6, and -10, or transforming growth factor-β were found in CAF-conditioned medium, but their secretion was unchanged after irradiation. Finally, immunogenic cell death responses in CAFs were studied by exploring the release of high motility group box-1 and ATP. Both alarmins remained undetectable before and after irradiation. In conclusion, CAFs play a powerful immunosuppressive effect over activated T-cells, and this effect remains unchanged after HD-RT. Importantly, CAFs do not switch on immunogenic cell death responses after exposure to HD-RT.

  12. ADSORPTION BEHAVIOR OF Pb(II) ON POTASSIUM HEXATITANATE WHISKER BY FAAS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the advantage of high surface area and strong adsorption ability of potassium hexatitanate whisker, a method to determine trace Pb(II) content by combining solid phase extraction with Flame atomic absorption spectrometry (FAAS) was established. The adsorptive behavior of potassium hexatitanate whisker to Pb(II), primary influencing factors of adsorption and elution and effect of coexistence ions were investigated systemically. The optimal analytical conditions were discussed and examined. It was found that the adsorption rate of potassium hexatitanate whisker to Pb(II) was 100% at pH 4.0. Pb(II) could be eluted from potassium tetratitanate whisker with HCl (2mol/L) under boiling water for 30min. The detection limit was 5.75ng/mL, and relative standard deviation was 1.66% (n=9, CPb=2.0μg/mL).

  13. ADSORPTION BEHAVIOR OF Pb(Ⅱ) ON POTASSIUM HEXATITANATE WHISKER BY FAAS

    Institute of Scientific and Technical Information of China (English)

    CHENG Yonghua; XU Wanzhen; YAN Yongsheng; JING Junjie

    2008-01-01

    Based on the advantage of high surface area and strong adsorption ability of potassium hexatitanate whisker, a method to determine trace Pb(Ⅱ) content by combining solid phase extraction with Flame atomic absorption spectrometry (FAAS) was established.The adsorptive behavior of potassium hexatitanate whisker to Pb(Ⅱ), primary influencing factors of adsorption and elation and effect of coexistence ions were investigated systemically.The optimal analytical conditions were discussed and examined.It was found that the adsorption rate of potassium hexatitanate whisker to Pb(Ⅱ) was 100% at pH 4.0.Pb(Ⅱ) could be elated from potassium tetratitanate whisker with HCI (2mol/L) under boiling water for 30min.The detection limit was 5.75ng/mL, and relative standard deviation was 1.66% (n=9, CPb=2.0μg/mL).

  14. Preparation of graphene oxide-manganese dioxide for highly efficient adsorption and separation of Th(IV)/U(VI).

    Science.gov (United States)

    Pan, Ning; Li, Long; Ding, Jie; Li, Shengke; Wang, Ruibing; Jin, Yongdong; Wang, Xiangke; Xia, Chuanqin

    2016-05-15

    Manganese dioxide decorated graphene oxide (GOM) was prepared via fixation of crystallographic MnO2 (α, γ) on the surface of graphene oxide (GO) and was explored as an adsorbent material for simultaneous removal of thorium/uranium ions from aqueous solutions. In single component systems (Th(IV) or U(VI)), the α-GOM2 (the weight ratio of GO/α-MnO2 of 2) exhibited higher maximum adsorption capacities toward both Th(IV) (497.5mg/g) and U(VI) (185.2 mg/g) than those of GO. In the binary component system (Th(IV)/U(VI)), the saturated adsorption capacity of Th(IV) (408.8 mg/g)/U(VI) (66.8 mg/g) on α-GOM2 was also higher than those on GO. Based on the analysis of various data, it was proposed that the adsorption process may involve four types of molecular interactions including coordination, electrostatic interaction, cation-pi interaction, and Lewis acid-base interaction between Th(IV)/U(VI) and α-GOM2. Finally, the Th(IV)/U(VI) ions on α-GOM2 can be separated by a two-stage desorption process with Na2CO3/EDTA. Those results displayed that the α-GOM2 may be utilized as an potential adsorbent for removing and separating Th(IV)/U(VI) ions from aqueous solutions.

  15. Highly efficient indoor air purification using adsorption-enhanced-photocatalysis-based microporous TiO2 at short residence time.

    Science.gov (United States)

    Lv, Jinze; Zhu, Lizhong

    2013-01-01

    A short residence time is a key design parameter for the removal of organic pollutants in catalyst-based indoor air purification systems. In this study, we synthesized a series of TiO2 with different micropore volumes and studied their removal efficiency of indoor carbonyl pollutants at a short residence time. Our results indicated that the superior adsorption capability of TiO2 with micropores improved its performance in the photocatalytic degradation of cyclohexanone, while the photocatalytic removal of the pollutant successfully kept porous TiO2 from becoming saturated. When treated with 1 mg m(-3) cyclohexanone at a relatively humidity of 18%, the adsorption amount on microporous TiO2 was 5.4-7.9 times higher than that on P25. Removal efficiency via photocatalysis followed'the same order as the adsorption amount: TiO2-5 > TiO2-20 > TiO2-60 > TiO2-180 > P25. The advantage of microporous TiO2 over P25 became more pronounced when the residence time declined from 0.072 to 0.036 s. Moreover, as the concentration of cyclohexanone deceased from 1000 ppb to 500 ppb, removal efficiency by microporous TiO2 increased more rapidly than P25.

  16. Conceptions of Ability.

    Science.gov (United States)

    Jagacinski, Carolyn M.; Nicholls, John G.

    Two different conceptions of ability are proposed. The first conception of ability is more differentiated and generally employed by adults and older children. Here ability level is defined with reference to the performance of others assuming that optimum effort was employed. High ability means higher than others. The second conception of ability…

  17. High embryogenic ability and regeneration from floral axis of Amorphophallus konjac (Araceae

    Directory of Open Access Journals (Sweden)

    Zhong Lin

    2017-03-01

    Full Text Available Amorphophallus konjac (Araceae a perennial herb, it has high medicinal and industrial value. In this study, a simple and efficient system for direct somatic embryogenesis and plantlet regeneration of Amorphophallus konjac was developed. The floral axis was used as the experimental material. The primary callus, developed from the floral axis grown on Murashige and Skoog (MS medium supplemented with different hormone combination at different concentrations. The highest rate of embryogenic callus formation was observed on the MS medium containing 9.04 µM 2, 4-dichlorophenoxyacetic acid (2, 4-D and 5.37 µM naphthalene acetic acid (NAA. The maximum induction rate was 79.8%, and the embryogenic calli were able to subculture on a medium containing similar hormone combination for over 1 year. The calli were also placed on different media for regeneration and it produced complete plants with shoots and root systems simultaneously. The highest differentiation rate of the embryogenic calli grown on differentiation medium supplemented with 8.88 µM 6-benzylaminopurine (6-BA and 5.37 µM NAA was 95.6%. Flow cytometry analysis showed no ploidy variation in all the regenerate plantlets.

  18. Fostering Creativity in the Classroom for High Ability Students: Context Does Matter

    Directory of Open Access Journals (Sweden)

    Liang See Tan

    2016-11-01

    Full Text Available Researchers have argued for the importance of the classroom context in developing students’ creative potential. However, the emphasis on a performative learning culture in the classroom does not favour creativity. Thus, how creative potential can be realised as one of the educational goals in the classrooms remains a key question. This study measured creativity across three secondary schools using the Wallach-Kogan Creative Thinking Test (WKCT. A total of 283 students enrolled in the Express programme and 290 students enrolled in the Integrated Programme (IP volunteered in the study. The same cohort of students took the 38-item WKCT twice; once at the beginning of Secondary One and then at the end of Secondary Three. Four aspects of creativity, namely fluency, flexibility, unusualness, and uniqueness, were investigated. Our analyses showed that (i IP students showed a greater increase in scores over time when compared to Express students; (ii when Programme and PSLE (Primary School Leaving Examination were used to predict creativity scores in a multiple regression, the predictive power of Programme increased from Secondary 1 to Secondary 3 while that of PSLE decreased; and (iii flexibility scores were more resistant to change than fluency scores. These findings suggest that the classroom context matters and that the removal of high-stakes examination can provide room for the development of creative potential.

  19. Rhizosphere selection of highly motile phenotypic variants of Pseudomonas fluorescens with enhanced competitive colonization ability.

    Science.gov (United States)

    Martínez-Granero, Francisco; Rivilla, Rafael; Martín, Marta

    2006-05-01

    Phenotypic variants of Pseudomonas fluorescens F113 showing a translucent and diffuse colony morphology show enhanced colonization of the alfalfa rhizosphere. We have previously shown that in the biocontrol agent P. fluorescens F113, phenotypic variation is mediated by the activity of two site-specific recombinases, Sss and XerD. By overexpressing the genes encoding either of the recombinases, we have now generated a large number of variants (mutants) after selection either by prolonged laboratory cultivation or by rhizosphere passage. All the isolated variants were more motile than the wild-type strain and appear to contain mutations in the gacA and/or gacS gene. By disrupting these genes and complementation analysis, we have observed that the Gac system regulates swimming motility by a repression pathway. Variants isolated after selection by prolonged cultivation formed a single population with a swimming motility that was equal to the motility of gac mutants, being 150% more motile than the wild type. The motility phenotype of these variants was complemented by the cloned gac genes. Variants isolated after rhizosphere selection belonged to two different populations: one identical to the population isolated after prolonged cultivation and the other comprising variants that besides a gac mutation harbored additional mutations conferring higher motility. Our results show that gac mutations are selected both in the stationary phase and during rhizosphere colonization. The enhanced motility phenotype is in turn selected during rhizosphere colonization. Several of these highly motile variants were more competitive than the wild-type strain, displacing it from the root tip within 2 weeks.

  20. Unusual and highly tunable missing-linker defects in zirconium metal-organic framework UiO-66 and their important effects on gas adsorption.

    Science.gov (United States)

    Wu, Hui; Chua, Yong Shen; Krungleviciute, Vaiva; Tyagi, Madhusudan; Chen, Ping; Yildirim, Taner; Zhou, Wei

    2013-07-17

    UiO-66 is a highly important prototypical zirconium metal-organic framework (MOF) compound because of its excellent stabilities not typically found in common porous MOFs. In its perfect crystal structure, each Zr metal center is fully coordinated by 12 organic linkers to form a highly connected framework. Using high-resolution neutron power diffraction technique, we found the first direct structural evidence showing that real UiO-66 material contains significant amount of missing-linker defects, an unusual phenomenon for MOFs. The concentration of the missing-linker defects is surprisingly high, ∼10% in our sample, effectively reducing the framework connection from 12 to ∼11. We show that by varying the concentration of the acetic acid modulator and the synthesis time, the linker vacancies can be tuned systematically, leading to dramatically enhanced porosity. We obtained samples with pore volumes ranging from 0.44 to 1.0 cm(3)/g and Brunauer-Emmett-Teller surface areas ranging from 1000 to 1600 m(2)/g, the largest values of which are ∼150% and ∼60% higher than the theoretical values of defect-free UiO-66 crystal, respectively. The linker vacancies also have profound effects on the gas adsorption behaviors of UiO-66, in particular CO2. Finally, comparing the gas adsorption of hydroxylated and dehydroxylated UiO-66, we found that the former performs systematically better than the latter (particularly for CO2) suggesting the beneficial effect of the -OH groups. This finding is of great importance because hydroxylated UiO-66 is the practically more relevant, non-air-sensitive form of this MOF. The preferred gas adsorption on the metal center was confirmed by neutron diffraction measurements, and the gas binding strength enhancement by the -OH group was further supported by our first-principles calculations.

  1. Adsorptive removal of phenol from aqueous solution with zeolitic imidazolate framework-67.

    Science.gov (United States)

    Pan, Yong; Li, Zhi; Zhang, Zhe; Tong, Xiong-Shi; Li, Hai; Jia, Chong-Zhi; Liu, Bei; Sun, Chang-Yu; Yang, Lan-Ying; Chen, Guang-Jin; Ma, De-Yun

    2016-03-15

    ZIF-67(zinc-methylimidazolate framework-67), one of the zeolitic imidazolate frameworks (ZIFs), was used for the removal of phenol from aqueous solutions via adsorption and shows high adsorption capacity for phenol. The thermodynamic and kinetic adsorption behavior of ZIF-67 for phenol in water with concentration ranging from 50 to 300 ppm were investigated in a batch reactor and a ZIF-67 packed column, respectively. The effects of pH, contact time, zeta potential of the adsorbent and temperature on the adsorption behavior were evaluated, and the results demonstrated that the adsorption is primarily brought about by a specific favorable interaction (electrostatic interaction) between phenol and ZIF-67 surface. The suitability of the Langmuir adsorption model to the equilibrium data was investigated for each phenol-adsorbent system, which the results showed that the equilibrium data for all the phenol-sorbent systems fitted the Langmuir model. Thermodynamic parameters such as Gibbs free energy are calculated from the experimental data at different temperatures. The adsorbent could be perfectly regenerated at 120 °C with little loss in the adsorption ability.

  2. First principles derived, transferable force fields for CO2 adsorption in Na-exchanged cationic zeolites.

    Science.gov (United States)

    Fang, Hanjun; Kamakoti, Preeti; Ravikovitch, Peter I; Aronson, Matthew; Paur, Charanjit; Sholl, David S

    2013-08-21

    The development of accurate force fields is vital for predicting adsorption in porous materials. Previously, we introduced a first principles-based transferable force field for CO2 adsorption in siliceous zeolites (Fang et al., J. Phys. Chem. C, 2012, 116, 10692). In this study, we extend our approach to CO2 adsorption in cationic zeolites which possess more complex structures. Na-exchanged zeolites are chosen for demonstrating the approach. These methods account for several structural complexities including Al distribution, cation positions and cation mobility, all of which are important for predicting adsorption. The simulation results are validated with high-resolution experimental measurements of isotherms and microcalorimetric heats of adsorption on well-characterized materials. The choice of first-principles method has a significant influence on the ability of force fields to accurately describe CO2-zeolite interactions. The PBE-D2 derived force field, which performed well for CO2 adsorption in siliceous zeolites, does not do so for Na-exchanged zeolites; the PBE-D2 method overestimates CO2 adsorption energies on multi-cation sites that are common in cationic zeolites with low Si/Al ratios. In contrast, a force field derived from the DFT/CC method performed well. Agreement was obtained between simulation and experiment not only for LTA-4A on which the force field fitting is based, but for other two common adsorbents, NaX and NaY.

  3. Biosynthesis of bifunctional iron oxyhydrosulfate by Acidithiobacillus ferroxidans and their application to coagulation and adsorption.

    Science.gov (United States)

    Gan, Min; Song, Zibo; Jie, Shiqi; Zhu, Jianyu; Zhu, Yaowu; Liu, Xinxing

    2016-02-01

    Coagulation and adsorption are important environmental technologies, which were widely applied in water treatment. In this study, a type of villous iron oxyhydrosulfate with low crystallinity, high content iron, sulfate and hydroxyl was synthesized by Acidithiobacillus ferrooxidans, which possessed coagulation and heavy metal adsorption ability simultaneously. The results showed that the Cu(II) adsorption capacity increased within a small range over the pH range of 3.0-5.0 but increased evidently over the range of 6.0-8.0. The maximal Cu(II) adsorption capacity of sample Af and Gf reached 50.97 and 46.08mg/g respectively. The optimum pH for Cr(VI) adsorption was 6.0, and the maximal adsorption capacity reached 51.32 and 59.57mg/g. The Langmuir isotherm can better describe the adsorption behavior of Cr(VI). Coagulation performance of the iron oxyhydrosulfate (Sh) has been significantly enhanced by polysilicic acid (PSA), which was mainly determined by PSA/Sh ratio, pH and coagulant dosage. Coagulation efficiency maintained approximately at 98% when the PSA/Sh ratio ranged from 0.4/0.1 to 1.0/0.1. Polysilicic acid worked efficiently in wide pH range extending, from 2 to 3.5. Coagulation performance improved significantly with the increasing of the coagulant dosage at lower dosage range, while, at higher dosage range, the improvement was not evident even with more coagulant addition.

  4. Kinetic Adsorption of Cd onto Nanometer Al2O3/Carbon Fibre

    Institute of Scientific and Technical Information of China (English)

    LI Yu; WANG Yue; HAN Wei; LI Su-wen; ZHAO Hui; ZHU Chang-yun; WANG Heng

    2005-01-01

    A new nanometer material, nano-Al2O3 with carbon fibre as the carrier, was employed for the removal of Cd with low concentrations from polluted water. The characterization of the material was carried out by means of SEM and TEM. Batch adsorption and elution experiments were carried out to determine the adsorption properties of Cd on the new adsorbent. The classical Thomas model was applied to estimating the equilibrium coefficients of Cd adsorption and the saturated adsorption ability. The results show that the Thomas model is fit for describing the kinetic adsorption process, and the maximum adsorption capacity of the nanometer Al2O3/carbon is 69.29 mg/g. The resulting information also indicates that the desorption of Cd eluted with de-ionized water at a rate of 9.8 mL/min can be neglected. With the advantage of a high adsorption capacity for removing low concentration Cd, the Al2O3/carbon fibre possesses the potentiality to be an effective adsorbent for the removal of Cd from polluted water.

  5. Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

    Science.gov (United States)

    Cortés-Arriagada, Diego; Toro-Labbé, Alejandro

    2016-11-01

    The ability of Al and Fe-doped graphene for the adsorption of trivalent and pentavalent methylated arsenic compounds was studied by quantum chemistry computations. The adsorption of trivalent methylarsenicals is reached with adsorption energies of 1.5-1.7 eV at neutral conditions; while, adsorption of pentavalent methylarsenicals reaches adsorption energies of 3.3-4.2 eV and 1.2-2.4 eV from neutral to low pH conditions, respectively. Moreover, the weakening of the interacting σAssbnd O bond in the pollutant structure played an important role in the stability of the adsorbent-adsorbate systems, determining the adsorption strength. In addition, the pollutant adsorption appears to be efficient in aqueous environments, with even high stability at ambient temperature; in this regard, it was determined that the trivalent and petavalent forms are mainly adsorbed in their neutral and anionic forms at neutral pH, respectively. Therefore, Al and Fe-doped graphene are considered as potential future materials for the removal of methylated arsenic pollutants.

  6. Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cortés-Arriagada, Diego, E-mail: dcarriagada@gmail.com; Toro-Labbé, Alejandro

    2016-11-15

    Graphical abstract: Quantum chemistry calculations show the ability of aluminum and iron doped graphene for the removal of methylated arsenicals in their trivalent and pentavalent states, with adsorption energies on the range of 1.5–4.2 eV, and high stability in a water environment. Display Omitted - Highlights: • Al and Fe-doped graphene serve as superior materials for adsorption of methylated arsenicals, including thioarsenicals. • Pentavalent arsenicals are adsorbed with higher adsorption energies (up to 4.2 eV) than trivalent arsenicals (up to 1.7 eV). • The adsorption strength is determined by the weakening of the interacting σAs−O bond in the pollutant. • The adsorption stability was studied in a water environment and molecular dynamics calculations were performed at 300 K. • Trivalent and petavalent forms are mainly adsorbed at neutral pH in their neutral and anionic forms, respectively. - Abstract: The ability of Al and Fe-doped graphene for the adsorption of trivalent and pentavalent methylated arsenic compounds was studied by quantum chemistry computations. The adsorption of trivalent methylarsenicals is reached with adsorption energies of 1.5–1.7 eV at neutral conditions; while, adsorption of pentavalent methylarsenicals reaches adsorption energies of 3.3–4.2 eV and 1.2–2.4 eV from neutral to low pH conditions, respectively. Moreover, the weakening of the interacting σAs−O bond in the pollutant structure played an important role in the stability of the adsorbent–adsorbate systems, determining the adsorption strength. In addition, the pollutant adsorption appears to be efficient in aqueous environments, with even high stability at ambient temperature; in this regard, it was determined that the trivalent and petavalent forms are mainly adsorbed in their neutral and anionic forms at neutral pH, respectively. Therefore, Al and Fe-doped graphene are considered as potential future materials for the removal of methylated arsenic

  7. The high tolerance to aluminium in crucian carp (Carassius carassius) is associated with its ability to avoid hypoxia.

    Science.gov (United States)

    Poléo, Antonio B S; Schjolden, Joachim; Sørensen, Jørgen; Nilsson, Göran E

    2017-01-01

    It is well known that aluminium is the principle toxicant killing fish in acidified freshwater systems, and it has been shown that crucian carp (Carassius carassius) can survive exposures to aqueous aluminium levels toxic to most other freshwater fish species. The crucian carp has a remarkable ability to survive anoxic conditions, and the aim of the present study was to reveal if the tolerance to aluminium can be associated with the ability to survive prolonged anoxia. Crucian carps were exposed to either acidic Al-rich water (pH 5.8; 960 μg Al/l), acidic Al-poor water (pH 5.8; 50 μg Al/l) or untreated control water (pH 6.5; 50 μg Al/l). Blood, muscle and gill samples were collected from exposed fish, and closed respirometry was performed to measure critical O2-tension an normoxic O2-consumption. The results show an increased gill surface area in Al-exposed fish, while the critical O2-tension did not change. The normoxic O2-consumption was lower in Al-exposed fish and might be due to a reduced metabolic rate. The results suggest that crucian carp exposed to aluminium do not become hypoxic, since haematocrit, plasma lactate and blood ethanol did not differ from that of control fish after 14 days of exposure. We also observed an initial loss of plasma chloride and sodium, followed by a stabilisation of these ions at a lower level than in control fish. The decrease in plasma ions caused a transient increase in haematocrit and water content in muscle tissue, returning to control levels when the ion concentrations stabilised, suggesting that the water balance was restored. We conclude that the high tolerance to aluminium in crucian carp is associated with its ability to avoid hypoxia as well as an ability to counteract a continuous loss of plasma ions.

  8. Highly efficient simultaneous ultrasonic-assisted adsorption of Pb(II), Cd(II), Ni(II) and Cu (II) ions from aqueous solutions by graphene oxide modified with 2,2'-dipyridylamine: Central composite design optimization.

    Science.gov (United States)

    Zare-Dorabei, Rouholah; Ferdowsi, Somayeh Moazen; Barzin, Ahmad; Tadjarodi, Azadeh

    2016-09-01

    In present work, a graphene oxide chemically modified with 2,2'-dipyridylamine (GO-DPA), was synthesized by simple, fast and low-cost process for the simultaneous adsorption of four toxic heavy metals, Pb(II), Cd(II), Ni(II) and Cu(II), from aqueous solutions. The synthesized adsorbent was characterized by FT-IR, XRD, XPS, SEM and AFM measurements. The effects of variables such as pH solution, initial ion concentrations, adsorbent dosage and sonicating time were investigated on adsorption efficiency by rotatable central composite design. The optimum conditions, specified as 8mg of adsorbent, 20mgL(-1) of each ion at pH 5 and short time of 4min led to the achievement of a high adsorption capacities. Ultrasonic power had important role in shortening the adsorption time of ions by enhancing the dispersion of adsorbent in solution. The adsorption kinetic studies and equilibrium isotherms for evaluating the mechanism of adsorption process showed a good fit to the pseudo-second order and Langmuir model, respectively. The maximum adsorption capacities (Qm) of this adsorbent were 369.749, 257.201, 180.893 and 358.824mgg(-1) for lead, cadmium, nickel and copper ions, respectively. The removal performance of adsorbent on the real wastewater samples also showed the feasibility of adsorbent for applying in industrial purposes.

  9. Selective adsorption of tannins onto hide collagen fibres

    Institute of Scientific and Technical Information of China (English)

    LIAO; Xuepin(廖学品); LU; Zhongbing(陆忠兵); SHI; Bi(石碧)

    2003-01-01

    Hide collagen of animals is used to prepare adsorbent material and its adsorption properties to tannins are investigated. It is indicated that the collagen fibres has excellent adsorption selectivity and high adsorption capacity to tannins. The adsorption rate of tannins is more than 90% whilst less than 10% of functional components are retained by the adsorbent. The adsorption mechanism of tannins onto hide collagen fibres is hydrogen-bonding association. Freundlich model can be used to describe the adsorption isotherms, and the pseudo-second-order rate model can be used to describe adsorption kinetics.

  10. Formation and mechanical properties of bulk Cu-Ti-Zr-Ni metallic glasses with high glass forming ability

    Institute of Scientific and Technical Information of China (English)

    YANG Ying-jun; KANG Fu-wei; XING Da-wei; SUN Jian-fei; SHEN Qing-ke; SHEN Jun

    2007-01-01

    Bulk amorphous Cu52.5Ti30Zr11.5Ni6 and Cu53.1Ti31.4Zr9.5Ni6 alloys with a high glass forming ability can be quenched into single amorphous rods with a diameter of 5 mm, and exhibit a high fracture strength of 2 212 MPa and 2 184 MPa under compressive condition, respectively. The stress-strain curves show nearly 2% elastic strain limit, yet display no appreciable macroscopic plastic deformation prior to the catastrophic fracture due to highly localized shear bands. The present work shows clearly evidence of molten droplets besides well-developed vein patterns typical of bulk metallic glasses on the fracture surface, suggesting that localized melting induced by adiabatic heating may occur during the final failure event.

  11. Highly Stable Hierarchical Flower-like β-In2S3 Assembled from 2D Nanosheets with high Adsorption-Photodecolorization Activities for the Treatment of Wastewater

    Science.gov (United States)

    Cheng, Yang; Niu, Helin; Chen, Jingshuai; Song, Jiming; Mao, Changjie; Zhang, Shengyi; Chen, Changle; Gao, Yuanhao

    2017-05-01

    The hierarchical flower-like β-In2S3 catalyst assembled from 2D nanosheets was prepared using an organic-component depletion method utilizing inorganic-organic hybrids indium diethyldithiocarbamate (In-DDTC) as a single-source precursor. The crystallization, morphology and composition of the as-synthesized β-In2S3 were characterized by XRD, SEM, TEM, EDS and XPS, respectively. The β-In2S3 possessed high specific surface area of 134.1 m2 g-1, adsorption capacity of 195.5 mg g-1 for methylene blue, and extreme photodecolorization speed under visible light irradiation for the complete removal of methyl orange (MO) dye within 15 min and tetracycline within 60 min. Although methyl orange concentration decreased quickly, the total organic carbon (TOC) decreased slowly. UV-vis and mass spectrometry (MS) were applied to analyze the intermediates coming from the photodecolorization of MO. In order to estimate the roles of active species during the decolorization of MO, trapping experiments were conducted to determine the main active species during the decolorization process. The results indicated that . O2 - radicals and e-1 were the key intermediates. This enhanced activity was attributed to its unique structures assembled from 2D nanosheets with thickness of ca. 5-7 nm, leading to high specific surface area, wide range of pore size distribution and great efficiency in absorbing light and electron/hole separation. The hierarchical flower-like β-In2S3 demonstrated great advantages in the treatment of various wastewater pollutants including textile dyes and antibiotics.

  12. Separating effective high density polyethylene segments from olefin block copolymers using high temperature liquid chromatography with a preloaded discrete adsorption promoting solvent barrier.

    Science.gov (United States)

    Chatterjee, Tirtha; Rickard, Mark A; Pearce, Eric; Pangburn, Todd O; Li, Yongfu; Lyons, John W; Cong, Rongjuan; deGroot, A Willem; Meunier, David M

    2016-09-23

    Recent advances in catalyst technology have enabled the synthesis of olefin block copolymers (OBC). One type is a "hard-soft" OBC with a high density polyethylene (HDPE) block and a relatively low density polyethylene (VLDPE) block targeted as thermoplastic elastomers. Presently, one of the major challenges is to fractionate HDPE segments from the other components in an experimental OBC sample (block copolymers and VLDPE segments). Interactive high temperature liquid chromatography (HTLC) is ineffective for OBC separation as the HDPE segments and block copolymer chains experience nearly identical enthalpic interactions with the stationary phase and co-elute. In this work we have overcome this challenge by using liquid chromatography under the limiting conditions of desorption (LC LCD). A solvent plug (discrete barrier) is introduced in front of the sample which specifically promotes the adsorption of HDPE segments on the stationary phase (porous graphitic carbon). Under selected thermodynamic conditions, VLDPE segments and block copolymer chains crossed the barrier while HDPE segments followed the pore-included barrier solvent and thus enabled separation. The barrier solvent composition was optimized and the chemical composition of fractionated polymer chains was investigated as a function of barrier solvent strength using an online Fourier-transform infrared (FTIR) detector. Our study revealed that both the HDPE segments as well as asymmetric block copolymer chains (HDPE block length≫VLDPE block length) are retained in the separation and the barrier strength can be tailored to retain a particular composition. At the optimum barrier solvent composition, this method can be applied to separate effective HDPE segments from the other components, which has been demonstrated using an experimental OBC sample.

  13. Computer-based numerical simulations of adsorption in nanostructures

    Science.gov (United States)

    Khashimova, Diana

    2014-08-01

    Zeolites are crystalline oxides with uniform, molecular-pore diameters of 3-14Å. Significant developments since 1950 made production of synthetic zeolites with high purity and controlled chemical composition possible. In powder-form, zeolites are major role-players in high-tech, industrial catalysis, adsorption, and ion exchange applications. Understanding properties of thin-film zeolites has been a focus of recent research. The ability to fine-tune desired macroscopic properties by controlled alteration at the molecular level is paramount. The relationships between macroscopic and molecular-level properties are established by experimental research. Because generating macroscopic, experimental data in a controlled laboratory can be prohibitively costly and time-consuming, reliable numerical simulations, which remove such difficulties, are an attractive alternative. Using a Configurational Biased Monte Carlo (CBMC) approach in grand canonical ensemble, numerical models for pure component and multicomponent adsorption processes were developed. Theoretical models such as ideal (IAST) and real adsorbed solution theory (RAST) to predict mixture adsorption in nanopores were used for comparison. Activity coefficients used in RAST calculations were determined from the Wilson, spreading pressure and COSMO-RS models. Investigative testing of the method on known materials, represented by all-silica zeolites such as MFI (channel type) and DDR (cage type), proved successful in replicating experimental data on adsorption of light hydrocarbons - alkanes, such as methane, ethane, propane and butane. Additionally, adsorption of binary and ternary mixtures was simulated. The given numerical approach developed can be a powerful, cost and time saving tool to predict process characteristics for different molecular-structure configurations. The approach used here for simulating adsorption properties of nanopore materials including process characteristics, may have great potential for

  14. Rapid and efficient treatment of wastewater with high-concentration heavy metals using a new type of hydrogel-based adsorption process.

    Science.gov (United States)

    Zhou, Guiyin; Liu, Chengbin; Chu, Lin; Tang, Yanhong; Luo, Shenglian

    2016-11-01

    In this study, a new type of double-network hydrogel sorbent was developed to remove heavy metals in wastewater. The amino-functionalized Starch/PAA hydrogel (NH2-Starch/PAA) could be conducted in a wide pH and the adsorption process could rapidly achieve the equilibrium. The adsorption capacity got to 256.4mg/g for Cd(II). Resultantly, even though Cd(II) concentration was as high as 180mg/L, the Cd(II) could be entirely removed using 1g/L sorbent. Furthermore, the desirable mechanical durability of the adsorbent allowed easy separation and reusability. In the fixed-bed column experiments, the treatment volume of the effluent with a high Cd(II) concentration of 200mg/L reached 2400BV (27.1L) after eight times cycle. The NH2-Starch/PAA overcame the deficiency of conventional sorbents that could not effectively treat the wastewater with relatively high metal concentrations. This work provides a new insight into omnidirectional enhancement of sorbents for removing high-concentration heavy metals in wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A highly stable MOF with a rod SBU and a tetracarboxylate linker: unusual topology and CO2 adsorption behaviour under ambient conditions.

    Science.gov (United States)

    Li, Ru-Jin; Li, Mian; Zhou, Xiao-Ping; Li, Dan; O'Keeffe, Michael

    2014-04-21

    A Mn-based rod metal-organic framework (MOF), ROD-6, with a new lrk net is synthesized. It represents an unusual type of MOF topology containing both a 1-periodic secondary building unit (rod SBU) and a polytopic linker (here 1,3,6,8-tetrakis(p-benzoic acid)pyrene), and also exhibits high stability (up to 485 °C) and unusual CO2 uptake behaviour and selectivity despite the lack of strong interacting sites, demonstrated by the low and increasing heat of adsorption.

  16. In Situ Synthesis of γ-AlOOH and Synchronous Adsorption Separation of V(V) from Highly Concentrated Cr(VI) Multiplex Complex solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hailin [National; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District,; Li, Ping [National; Wang, Zheming [Physcial; Zhang, Xin [Physcial; Zheng, Shili [National; Zhang, Yi [National

    2017-07-13

    Boehmite (γ-AlOOH) was synthesized to selectively adsorb V(V) from K2CrO4-KVO3-H2O solutions with highly concentrated Cr(VI) and low concentration V(V). The synthesized γ-AlOOH has a BET surface area of 433.2 m2/g and an average pore size of 3.5 nm. It possesses a maximum adsorption capacity of V(V) of 1.53 mmol/g from K2CrO4-KVO3-H2O solutions. The adsorption of V(V) onto γ-AlOOH follows the Langmuir isotherm model and pseudo-second-order kinetics equation by forming innersphere complexes while the Cr(VI) adsorption forms both inner-sphere and outer-sphere chromate complexes depending on solution pH. The γ-AlOOH was further synthesized in situ by adding HNO3 into the K2CrO4-KAlO2- KVO3-H2O solutions and then used for synchronous adsorption of V(V) and Cr(VI), resulting in increased adsorption capacity of V(V) of 2.88 mmol/g and decreased adsorption capacity of Cr(VI) to 0.073 mmol/g, respectively. In the latter process, adsorption pH values were adjustable, and adsorption reached equilibrium instantaneously, supporting a novel in situ synthesis and adsorption integration strategy with adjustable surface charge of adsorbent and disappearance of diffusion effect.

  17. Sports genetics: the PPARA gene and athletes’ high ability in endurance sports. A systematic review and meta-analysis

    Science.gov (United States)

    Tuvblad, C; Forero, DA

    2015-01-01

    A meta-analysis was performed with the aim of re-evaluating the role of the peroxisome proliferator activated receptor alpha (PPARA) gene intron 7 G/C polymorphism (rs4253778) in athletes’ high ability in endurance sports. Design: A meta-analysis of case control studies assessing the association between the G/C polymorphisms of the PPARA gene and endurance sports was conducted. The Cochrane Review Manager software was used to compare the genotype and allele frequencies between endurance athletes and controls to determine whether a genetic variant is more common in athletes than in the general population. Five studies, encompassing 760 endurance athletes and 1792 controls, fulfilled our inclusion criteria. The pooled odds ratio (and confidence intervals, CIs) for the G allele compared to the C allele was 1.65 (95% CI 1.39-1.96). The pooled OR for the GG genotype compared to the GC genotype was 1.79 (95% CI 1.44-2.22), and for the GG genotype compared to the CC genotype 2.37 (95% CI 1.40-3.99). There was no evidence of heterogeneity (I2 =0%) or of publication bias. Athletes with high ability in endurance sports had a higher frequency of the GG genotype and G allele. PMID:26985127

  18. Action of Plant Growth Regulators. IV. Adsorption of Unsubstituted and 2,6-Dichloro-aromatic Acids to Oat Monolayers

    Science.gov (United States)

    Brian, R. C.

    1967-01-01

    The adsorption of chloro-aromatic acids to monomolecular layers of oat squashes is reported in earlier papers but it was not possible by the technique used, to measure unambiguously the adsorption of unsubstituted and 2,6-dichloro-aromatic acids. This has now been achieved by a modification of the earlier method and involves assessments of competitive adsorption between the unknown acid and a standard acid, using measurements of surface potential. Benzoic and phenoxyacetic acids were not adsorbed but phenylacetic acid was weakly adsorbed. The second ring in naphthalene and naphthoxyacetic acids greatly increased adsorption. Substitution of the 2 and 6 positions in the phenyl and phenoxyacetic acids resulted in low adsorption but 2,6-disubstituted phenoxybutyric and benzoic acids were more highly adsorbed. The adsorption values from earlier work are combined and discussed in relation to the growth-regulating activity of the acids. It is conciuded that there is no direct relation embracing all acids between adsorption and activity, notable exceptions being those substituted by chlorine in the 3-position of the aromatic ring. However, for a number of acids it is suggested that activity is limited not only by their ability to interact at enzyme sites but also by the amount of acid immobilised by adsorption when moving to these sites. It is also concluded that the hydrophilic/lipophilic balance of a growth regulator sometimes used as a guide to its activity, is an unreliable indication of interfacial behaviour. PMID:16656642

  19. Comparison of quartz sand, anthracite, shale and biological ceramsite for adsorptive removal of phosphorus from aqueous solution.

    Science.gov (United States)

    Jiang, Cheng; Jia, Liyue; Zhang, Bo; He, Yiliang; Kirumba, George

    2014-02-01

    The choice of substrates with high phosphorus adsorption capacity is vital for sustainable phosphorus removal from waste water in constructed wetlands. In this study, four substrates were used: quartz sand, anthracite, shale and biological ceramsite. These substrate samples were characterized by Xray diffractometry and scanning electron microscopy studies for their mineral components (chemical components) and surface characteristics. The dynamic experimental results revealed the following ranking order for total phosphorus (TP) removal efficiency: anthracite > biological ceramsite > shale > quartz sand. The adsorptive removal capacities for TP using anthracite, biological ceramsite, shale and quartz sand were 85.87, 81.44, 59.65, and 55.98 mg/kg, respectively. Phosphorus desorption was also studied to analyze the substrates' adsorption efficiency in wastewater treatment as well as the substrates' ability to be reused for treatment. It was noted that the removal performance for the different forms of phosphorus was dependent on the nature of the substrate and the adsorption mechanism. A comparative analysis showed that the removal of particulate phosphorus was much easier using shale. Whereas anthracite had the highest soluble reactive phosphorus (SRP) adsorptive capacity, biological ceramsite had the highest dissolved organic phosphorus (DOP) removal capacity. Phosphorus removal by shale and biological ceramsite was mainly through chemical adsorption, precipitation or biological adsorption. On the other hand, phosphorus removal through physical adsorption (electrostatic attraction or ion exchange) was dominant in anthracite and quartz sand.

  20. High-Ability Students' Perspectives on an Affective Curriculum in a Diverse, University-Based Summer Residential Enrichment Program

    Science.gov (United States)

    Jen, Enyi; Gentry, Marcia; Moon, Sidney M.

    2017-01-01

    The purpose of this study was to investigate how high-ability students experienced their participation in an affective curriculum through small-group discussions in a diverse, university-based, summer enrichment program for talented youth. The investigation included two closely related studies. The first study included 77 high-ability students…

  1. Social and Affective Concerns High-Ability Adolescents Indicate They Would Like to Discuss with a Caring Adult: Implications for Educators

    Science.gov (United States)

    Jen, Enyi; Wu, Jiaxi; Gentry, Marcia

    2016-01-01

    This exploratory study investigated the social and affective concerns of 280 high-ability students in Grades 5 through 12 who participated in a summer residential program. Content analysis of responses from an open-ended survey indicated that high-ability adolescents expressed concerns regarding feelings and emotions, future aspirations, and…

  2. Surface plasmon resonance biosensor with high anti-fouling ability for the detection of cardiac marker troponin T.

    Science.gov (United States)

    Liu, Jen Tsai; Chen, Ching Jung; Ikoma, Toshiyuki; Yoshioka, Tomohiko; Cross, Jeffrey S; Chang, Shwu-Jen; Tsai, Jang-Zern; Tanaka, Junzo

    2011-10-03

    Designing a surface recognition layer with high anti-fouling ability, high affinity, and high specificity is an important issue to produce high sensitivity biosensing transducers. In this study, a self-assembled monolayer (SAM) consisting of a homogeneous mixture of oligo(ethylene glycol) (OEG)-terminated alkanethiolate and mercaptohexadecanoic acid (MHDA) on Au was employed for immobilizing troponin T antibody and applied in detecting cardiac troponin T by using surface plasmon resonance (SPR). The mixed SAM showed no phase segregation and exhibited human serum albumin resistance, particularly with an antibody-immobilized surface. X-ray photoemission spectra revealed that the chemical composition ratio of OEG to the mixed SAM was 69% and the OEG packing density was 82%. The specific binding of troponin T on the designed surface indicated a good linear correlation (R=0.991, P<0.0009) at concentrations lower than 50 μgmL(-1) with the limit of detection of 100 ngmL(-1) using a SPR measuring instrument. It is concluded that the mixed SAM functions as designed since it has high detection capability, high accuracy and reproducibility, as well as shows strong potential to be applied in rapid clinical diagnosis for label-free detection within 2 min.

  3. Capability of defective graphene-supported Pd13 and Ag13 particles for mercury adsorption

    Science.gov (United States)

    Meeprasert, Jittima; Junkaew, Anchalee; Rungnim, Chompoonut; Kunaseth, Manaschai; Kungwan, Nawee; Promarak, Vinich; Namuangruk, Supawadee

    2016-02-01

    Reactivity of single-vacancy defective graphene (DG) and DG-supported Pdn and Agn (n = 1, 13) for mercury (Hg0) adsorption has been studied using density functional theory calculation. The results show that Pdn binds defective site of DG much stronger than the Agn, while metal nanocluster binds DG stronger than single metal atom. Metal clustering affects the adsorption ability of Pd composite while that of Ag is comparatively less. The binding strength of -8.49 eV was found for Pd13 binding on DG surface, indicating its high stability. Analyses of structure, energy, partial density of states, and d-band center (ɛd) revealed that the adsorbed metal atom or cluster enhances the reactivity of DG toward Hg adsorption. In addition, the Hg adsorption ability of Mn-DG composite is found to be related to the ɛd of the deposited Mn, in which the closer ɛd of Mn to the Fermi level correspond to the higher adsorption strength of Hg on Mn-DG composite. The order of Hg adsorption strength on Mn-DG composite are as follows: Pd13 (-1.68 eV) >> Ag13 (-0.67 eV) ∼ Ag1 (-0.69 eV) > Pd1 (-0.62 eV). Pd13-DG composite is therefore more efficient sorbent for Hg0 removal in terms of high stability and high adsorption reactivity compared to the Ag13. Further design of highly efficient carbon based sorbents should be focused on tailoring the ɛd of deposited metals.

  4. Europium-engineered iron oxide nanocubes with high T1 and T2 contrast abilities for MRI in living subjects

    Science.gov (United States)

    Yang, Lijiao; Zhou, Zijian; Liu, Hanyu; Wu, Changqiang; Zhang, Hui; Huang, Guoming; Ai, Hua; Gao, Jinhao

    2015-04-01

    Magnetic resonance imaging (MRI) contrast agents with both positive (T1) and negative (T2) contrast abilities are needed in clinical diagnosis for fault-free accurate detection of lesions. We report a facile synthesis of europium-engineered iron oxide (EuIO) nanocubes as T1 and T2 contrast agents for MRI in living subjects. The Eu(iii) oxide-embedded iron oxide nanoparticles significantly increase the T1 relaxivity with an enhanced positive contrast effect. EuIO nanocubes with 14 nm in diameter showed a high r1 value of 36.8 mM-1 s-1 with respect to total metal ions (Fe + Eu), which is about 3 times higher than that of Fe3O4 nanoparticles with similar size. Moreover, both r1 and r2 values of EuIO nanocubes can be tuned by varying their sizes and Eu doping ratios. After citrate coating, EuIO nanocubes can provide enhanced T1 and T2 contrast effects in small animals, particularly in the cardiac and liver regions. This work may provide an insightful strategy to design MRI contrast agents with both positive and negative contrast abilities for biomedical applications.Magnetic resonance imaging (MRI) contrast agents with both positive (T1) and negative (T2) contrast abilities are needed in clinical diagnosis for fault-free accurate detection of lesions. We report a facile synthesis of europium-engineered iron oxide (EuIO) nanocubes as T1 and T2 contrast agents for MRI in living subjects. The Eu(iii) oxide-embedded iron oxide nanoparticles significantly increase the T1 relaxivity with an enhanced positive contrast effect. EuIO nanocubes with 14 nm in diameter showed a high r1 value of 36.8 mM-1 s-1 with respect to total metal ions (Fe + Eu), which is about 3 times higher than that of Fe3O4 nanoparticles with similar size. Moreover, both r1 and r2 values of EuIO nanocubes can be tuned by varying their sizes and Eu doping ratios. After citrate coating, EuIO nanocubes can provide enhanced T1 and T2 contrast effects in small animals, particularly in the cardiac and liver

  5. New V(IV)-based metal-organic framework having framework flexibility and high CO2 adsorption capacity.

    Science.gov (United States)

    Liu, Ying-Ya; Couck, Sarah; Vandichel, Matthias; Grzywa, Maciej; Leus, Karen; Biswas, Shyam; Volkmer, Dirk; Gascon, Jorge; Kapteijn, Freek; Denayer, Joeri F M; Waroquier, Michel; Van Speybroeck, Veronique; Van Der Voort, Pascal

    2013-01-07

    A vanadium based metal-organic framework (MOF), VO(BPDC) (BPDC(2-) = biphenyl-4,4'-dicarboxylate), adopting an expanded MIL-47 structure type, has been synthesized via solvothermal and microwave methods. Its structural and gas/vapor sorption properties have been studied. This compound displays a distinct breathing effect toward certain adsorptives at workable temperatures. The sorption isotherms of CO(2) and CH(4) indicate a different sorption behavior at specific temperatures. In situ synchrotron X-ray powder diffraction measurements and molecular simulations have been utilized to characterize the structural transition. The experimental measurements clearly suggest the existence of both narrow pore and large pore forms. A free energy profile along the pore angle was computationally determined for the empty host framework. Apart from a regular large pore and a regular narrow pore form, an overstretched narrow pore form has also been found. Additionally, a variety of spectroscopic techniques combined with N(2) adsorption/desorption isotherms measured at 77 K demonstrate that the existence of the mixed oxidation states V(III)/V(IV) in the titled MOF structure compared to pure V(IV) increases the difficulty in triggering the flexibility of the framework.

  6. Topology of genetic associations between regional gray matter volume and intellectual ability: Evidence for a high capacity network.

    Science.gov (United States)

    Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Hedman, Anna M; van den Heuvel, Martijn P; van Haren, Neeltje E M; Kahn, René S; Pol, Hilleke E Hulshoff

    2016-01-01

    Intelligence is associated with a network of distributed gray matter areas including the frontal and parietal higher association cortices and primary processing areas of the temporal and occipital lobes. Efficient information transfer between gray matter regions implicated in intelligence is thought to be critical for this trait to emerge. Genetic factors implicated in intelligence and gray matter may promote a high capacity for information transfer. Whether these genetic factors act globally or on local gray matter areas separately is not known. Brain maps of phenotypic and genetic associations between gray matter volume and intelligence were made using structural equation modeling of 3T MRI T1-weighted scans acquired in 167 adult twins of the newly acquired U-TWIN cohort. Subsequently, structural connectivity analyses (DTI) were performed to test the hypothesis that gray matter regions associated with intellectual ability form a densely connected core. Gray matter regions associated with intellectual ability were situated in the right prefrontal, bilateral temporal, bilateral parietal, right occipital and subcortical regions. Regions implicated in intelligence had high structural connectivity density compared to 10,000 reference networks (p=0.031). The genetic association with intelligence was for 39% explained by a genetic source unique to these regions (independent of total brain volume), this source specifically implicated the right supramarginal gyrus. Using a twin design, we show that intelligence is genetically represented in a spatially distributed and densely connected network of gray matter regions providing a high capacity infrastructure. Although genes for intelligence have overlap with those for total brain volume, we present evidence that there are genes for intelligence that act specifically on the subset of brain areas that form an efficient brain network.

  7. On Preparation of High EGCG Catechinsby Means of Polyamide Adsorption%聚酰胺吸附法制备高 EGCG 儿茶素

    Institute of Scientific and Technical Information of China (English)

    罗赛; 龚正礼

    2016-01-01

    通过聚酰胺吸附法制备高 EGCG 儿茶素.以绿茶茶末为原料,经热水浸提,离心除渣,聚酰胺分离,浓缩干燥,得到 EGCG 儿茶素.结果表明,500 mL 聚酰胺吸附13.75 g EGCG 达到饱和;70%乙醇洗脱物中 EGCG 质量分数为63.200%;产品质量分数高于有机溶剂萃取产物;中试产品质量指标儿茶素超过75%,EGCG 超过55%,得率超过10%.得出该实验方法效果显著,工艺条件可行.%High EGCG catechins has been prepared by means of the polyamide adsorption .Firstly ,with the dust tea as raw materials ,extraction has been conducted by hot water and centrifugal cleaning .Secondly , the preparation has been done by means of polyamide adsorption .Lastly ,dryness has been concentrated and EGCG catechins got .Results show that 500 ml polyamide adsorption of 13 .75 g EGCG hasreached satu-ration .The EGCG content in the 70% ethanol elution is 63 .200% .The product is higher than that in organic sol-vent extracts .Pilot product quality in dicators catechin exceed 75% ,EGCG exceed 55% ,yield exceed 10% .It is concluded that the experimental method has led to significant results ,and that the process conditions is feasible .

  8. Preparation of highly developed mesoporous activated carbon fiber from liquefied wood using wood charcoal as additive and its adsorption of methylene blue from solution.

    Science.gov (United States)

    Ma, Xiaojun; Zhang, Fan; Zhu, Junyan; Yu, Lili; Liu, Xinyan

    2014-07-01

    Activated carbon fiber (C-WACF) with super high surface area and well-developed small mesopores were prepared by liquefied wood and uses wood charcoal (WC) as additive. The characterization and properties of C-WACF were investigated by XRD, XPS and N2 adsorption. Results showed the pore development was significant at temperatures >750°C, and reached a maximum BET surface area (2604.7 m(2)/g) and total pore volume (1.433 cm(3)/g) at 850°C, of which 86.8% was from the contribution of the small mesopores of 2-4 nm. It was also found that the mesopore volume and methylene blue adsorption of C-WACF were highly increased as the temperature increases from 750 to 850°C. Additionally, the reduction of graphitic layers, the obvious changes of functional groups and the more unstable carbons on the surface of C-WACF, which played important roles in the formation of mesopores, were also observed.

  9. Density functional theory study on the adsorption and decomposition of the formic acid catalyzed by highly active mushroom-like Au@Pd@Pt tri-metallic nanoparticles.

    Science.gov (United States)

    Duan, Sai; Ji, Yong-Fei; Fang, Ping-Ping; Chen, Yan-Xia; Xu, Xin; Luo, Yi; Tian, Zhong-Qun

    2013-04-07

    Local structures and adsorption energies of a formic acid molecule and its decomposed intermediates (H, O, OH, CO, HCOO, and COOH) on highly electrocatalytically active mushroom-like Au-core@Pd-shell@Pt-cluster nanoparticles with two atomic layers of the Pd shell and stoichiometric Pt coverage of around half-monolayer (Au@2 ML Pd@0.5 ML Pt) have been investigated by first principles calculations. The adsorption sites at the center (far away from the Pt cluster) and the edge (close to the Pt cluster) are considered and compared. Significant repulsive interaction between the edge sites and CO is observed. The calculated potential energy surfaces demonstrate that, with respect to the center sites, the CO2 pathway is considerably promoted in the edge area. Our results reveal that the unique edge structure of the Pt cluster is responsible for the experimentally observed high electrocatalytic activity of the Au@Pd@Pt nanoparticles toward formic acid oxidation. Such microscopic understanding should be useful for the design of new electrochemical catalysts.

  10. High cadmium-binding ability of a novel Colocasia esculenta metallothionein increases cadmium tolerance in Escherichia coli and tobacco.

    Science.gov (United States)

    Kim, Yeon-Ok; Patel, Darshan H; Lee, Dae-Seok; Song, Younho; Bae, Hyeun-Jong

    2011-01-01

    Experimental evidence in vivo as to the functional roles and binding properties to cadmium (Cd) of type-2 plants metallothionein (MT) has been limited thus far. We investigated the biological role of metallothionein from Colocasia esculenta (CeMT2b) in Escherichia coli and tobacco, and developed a new model for the relationship between Cd tolerance and Cd-binding ability. Heterologous expression of CeMT2b in Escherichia coli greatly enhanced Cd tolerance and accumulated Cd content as compared to control cells. The molecular weight of CeMT2b increased with Cd, and CeMT2b bound up to 5.96±1 molar ratio (Cd/protein). Under Cd stress, transgenic tobacco plants displayed much better seedling growth and high Cd accumulation than the wild type. The presence of an extra CXC motif in CeMT2b contributed to the enhanced Cd-tolerance. The present study provides the first insight into the ability of type-2 plant MT to bind physiological Cd.

  11. Europium-engineered iron oxide nanocubes with high T1 and T2 contrast abilities for MRI in living subjects.

    Science.gov (United States)

    Yang, Lijiao; Zhou, Zijian; Liu, Hanyu; Wu, Changqiang; Zhang, Hui; Huang, Guoming; Ai, Hua; Gao, Jinhao

    2015-04-21

    Magnetic resonance imaging (MRI) contrast agents with both positive (T1) and negative (T2) contrast abilities are needed in clinical diagnosis for fault-free accurate detection of lesions. We report a facile synthesis of europium-engineered iron oxide (EuIO) nanocubes as T1 and T2 contrast agents for MRI in living subjects. The Eu(iii) oxide-embedded iron oxide nanoparticles significantly increase the T1 relaxivity with an enhanced positive contrast effect. EuIO nanocubes with 14 nm in diameter showed a high r1 value of 36.8 mM(-1) s(-1) with respect to total metal ions (Fe + Eu), which is about 3 times higher than that of Fe3O4 nanoparticles with similar size. Moreover, both r1 and r2 values of EuIO nanocubes can be tuned by varying their sizes and Eu doping ratios. After citrate coating, EuIO nanocubes can provide enhanced T1 and T2 contrast effects in small animals, particularly in the cardiac and liver regions. This work may provide an insightful strategy to design MRI contrast agents with both positive and negative contrast abilities for biomedical applications.

  12. Enhancement of glass-forming ability of Fe-based bulk metallic glasses with high saturation magnetic flux density

    Directory of Open Access Journals (Sweden)

    Mingxiao Zhang

    2012-06-01

    Full Text Available The effects of substituting Fe with Ni on thermal properties, glass-forming ability (GFA and magnetic properties of Fe76-xNixMo3.5P10C4B4Si2.5 (x = 0−30 at.% alloys were investigated in detail. The breadth of the supercooled liquid region was found to gradually increase from 42 to 55 K with increasing Ni content to 30 at.%. When x = 5 at.%, the alloy composition approached a eutectic point, resulting in an increase in GFA. As a result, FeNiMoPCBSi bulk metallic glasses with critical diameters up to 5.5 mm were successfully synthesized by copper mold casting. These glassy alloys exhibit a high saturation magnetic flux density of 0.75−1.21 T and excellent soft magnetic properties, i.e., low coercive force of 1.1−2.0 A/m, and high effective permeability of 14400−19700 at 1 kHz under a field of 1 A/m. The reasons for the high stability of the supercooled liquid, and the high GFA as well as excellent soft magnetic properties are discussed in this article.

  13. Adsorption of lead over graphite oxide.

    Science.gov (United States)

    Olanipekun, Opeyemi; Oyefusi, Adebola; Neelgund, Gururaj M; Oki, Aderemi

    2014-01-24

    The adsorption efficiency and kinetics of removal of lead in presence of graphite oxide (GO) was determined using the Atomic Absorption Spectrophotometer (AAS). The GO was prepared by the chemical oxidation of graphite and characterized using FTIR, SEM, TGA and XRD. The adsorption efficiency of GO for the solution containing 50, 100 and 150 ppm of Pb(2+) was found to be 98%, 91% and 71% respectively. The adsorption ability of GO was found to be higher than graphite. Therefore, the oxidation of activated carbon in removal of heavy metals may be a viable option to reduce pollution in portable water. Published by Elsevier B.V.

  14. Adsorption affinity of anions on metal oxyhydroxides

    Science.gov (United States)

    Pechenyuk, S. I.; Semushina, Yu. P.; Kuz'mich, L. F.

    2013-03-01

    The dependences of anion (phosphate, carbonate, sulfate, chromate, oxalate, tartrate, and citrate) adsorption affinity anions from geometric characteristics, acid-base properties, and complex forming ability are generalized. It is shown that adsorption depends on the nature of both the anions and the ionic medium and adsorbent. It is established that anions are generally grouped into the following series of adsorption affinity reduction: PO{4/3-}, CO{3/2-} > C2O{4/2-}, C(OH)(CH2)2(COO){3/3-}, (CHOH)2(COO){2/2-} > CrO{4/2-} ≫ SO{4/2-}.

  15. Protein Adsorption in Three Dimensions

    Science.gov (United States)

    Vogler, Erwin A.

    2011-01-01

    initially-adsorbed protein. Interphase protein concentration CI increases as VI decreases, resulting in slow reduction in interfacial energetics. Steady-state is governed by a net partition coefficient P=(/CBCI). In the process of occupying space within the interphase, adsorbing protein molecules must displace an equivalent volume of interphase water. Interphase water is itself associated with surface-bound water through a network of transient hydrogen bonds. Displacement of interphase water thus requires an amount of energy that depends on the adsorbent surface chemistry/energy. This “adsorption-dehydration” step is the significant free-energy cost of adsorption that controls the maximum amount of protein that can be adsorbed at steady state to a unit adsorbent-surface area (the adsorbent capacity). As adsorbent hydrophilicity increases, protein adsorption monotonically decreases because the energetic cost of surface dehydration increases, ultimately leading to no protein adsorption near an adsorbent water wettability (surface energy) characterized by a water contact angle θ → 65°. Consequently, protein does not adsorb (accumulate at interphase concentrations greater than bulk solution) to more hydrophilic adsorbents exhibiting θ protein/surface interactions can be highly favorable, causing protein to adsorb in multilayers in a relatively thick interphase. A straightforward, three-component free energy relationship captures salient features of protein adsorption to all surfaces predicting that the overall free energy of protein adsorption ΔGadso is a relatively small multiple of thermal energy for any surface chemistry (except perhaps for bioengineered surfaces bearing specific ligands for adsorbing protein) because a surface chemistry that interacts chemically with proteins must also interact with water through hydrogen bonding. In this way, water moderates protein adsorption to any surface by competing with adsorbing protein molecules. This Leading Opinion ends

  16. Carbon doped molybdenum disulfide nanosheets stabilized on graphene for the hydrogen evolution reaction with high electrocatalytic ability

    Science.gov (United States)

    Li, Yong; Wang, Jiao; Tian, Xike; Ma, Longlong; Dai, Chu; Yang, Chao; Zhou, Zhaoxin

    2016-01-01

    Fabricating a cost effective hydrogen evolution reaction catalyst without using precious metal elements is in crucial demand for environmentally-benign energy production. In this work, the thin and edge-rich molybdenum disulfide nanosheets, with carbon doped in the interlayers and decorated on graphene, were developed by a facile solvothermal process. The as-synthesized nanohybrids exhibited high catalytic ability for the hydrogen evolution electrochemical reaction with an onset overpotential of 0.165 mV and a Tafel slope of 46 mV dec-1. Furthermore, the prepared nanohybrids also showed better durability and stability. Our work may lead to a potential method for in situ production of metal carbide-sulphur hybrid nanomaterials with promising applications for the hydrogen evolution reaction.Fabricating a cost effective hydrogen evolution reaction catalyst without using precious metal elements is in crucial demand for environmentally-benign energy production. In this work, the thin and edge-rich molybdenum disulfide nanosheets, with carbon doped in the interlayers and decorated on graphene, were developed by a facile solvothermal process. The as-synthesized nanohybrids exhibited high catalytic ability for the hydrogen evolution electrochemical reaction with an onset overpotential of 0.165 mV and a Tafel slope of 46 mV dec-1. Furthermore, the prepared nanohybrids also showed better durability and stability. Our work may lead to a potential method for in situ production of metal carbide-sulphur hybrid nanomaterials with promising applications for the hydrogen evolution reaction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07370g

  17. Adsorption of Chlortetracycline from Water by Rectories

    Institute of Scientific and Technical Information of China (English)

    吕国诚; 吴丽梅; 王晓龙; 廖立兵; 王小雨

    2012-01-01

    The removal of antibiotics from water by clay minerals has become the focus of research due to their strong adsorptive ability. In this study, adsorption of chlortetracycline (CTC) onto rectories was conducted and the effects of time, concentration, temperature and pH were investigated. Experimental results showed that adsorption equilibrium was reached in 8 h. Based on the Langmuir model, the maximum adsorption capacity of CTC on rectories was 177.7 mg·g 1 at room temperature. By the study on adsorption dynamics, it is found that the kinetic date fit the pseudo-second-order model well. The adsorption of CTC by rectories is endothermic and the free energy is in the range of 10 to 30 kJ·mol 1 . The pH value of solution has significant effects on adsorption and the optimal pH is at acidity (pH 2-6). At concentration of 2500 mg·L 1 , the intercalated CTC produces an interlayer space with a height of 1.38 nm, which is 1.12 nm in raw rectories, suggesting that the adsorption occurs between layers of rectories.

  18. Thermodynamic evaluation of activated charcoal as a poison antidote by high-performance liquid chromatography. I: Derivation and validation of an equation for Gibbs free energy of liquid-solid adsorption.

    Science.gov (United States)

    Kleeman, W P; Bailey, L C

    1988-06-01

    An in vitro method utilizing high-performance liquid chromatography (HPLC) was developed in order to investigate the adsorptive process between activated charcoal and various drugs and toxic chemicals by measuring their Gibbs free energy of adsorption from various acetonitrile:water mobile phases. This report details the derivation and validation of the equation for calculating the Gibbs free energy of liquid-solid adsorption via HPLC. The derived equation incorporates the following experimental parameters: specific surface area of the adsorbent, specific retention volume of the solute, molar volume of the mobile phase, and surface concentration of the solute in a predefined standard state. This equation was validated by means of a closed thermodynamic cycle composed of three segments. Each segment represents a different physical process: gas-solid adsorption of methyl iodide on activated charcoal, gas-liquid solution of methyl iodide in n-hexadecane, and liquid-solid adsorption of methyl iodide on activated charcoal from n-hexadecane. The Gibbs free energy for each of these thermodynamic processes was determined by the appropriate chromatographic technique. Since the cycle did not balance because it did not account for the interaction of n-hexadecane and activated charcoal, it was altered to include a gas-liquid-solid chromatographic technique. When the Gibbs free energies of solution and gas-solid adsorption determined by this chromatographic technique were incorporated into the cycle, the resulting imbalance was only 0.213 kJ/mol (1.1%), thereby validating the derived equation.

  19. Activated Carbon Preparation and Modification for Adsorption

    Science.gov (United States)

    Cao, Yuhe

    . The adsorption capacities of these active carbon samples were almost three times that of zeolite. However, the un-modified active carbon had the highest adsorption capacity for butanol vapor (259.6 mg g-1), compared to 222.4 mg g-1 after 10% H2O2 hydrothermal treatment. Both modified and un-modified active carbon can be easily regenerated for repeatable adsorption by heating to 150 °C. Therefore, surface oxygen groups significantly reduced the adsorption capacity of active carbons for butanol vapor. In addition, original active carbon and AC samples modified by nitric acid hydrothermal modification were assessed for their ability to adsorb butanol vapor. The specific surface area and oxygen-containing functional groups of AC were tested before and after modification. The adsorption capacity of unmodified AC samples were the highest. Hydrothermal oxidation of AC with HNO3 increased the surface oxygen content, Brunauer-Emmett-Teller (BET) surface area, micropore, mesopore and total pore volume of AC. Although the pore structure and specific surface area were greatly improved after hydrothermal oxidization with 4 M HNO3, the increased oxygen on the surface of AC decreased the dynamic adsorption capacity. In order to get high adsorption capacity adsorbents, we used corn stalk as precursor to fabricate porous carbon. ACs were prepared through chemical activation of biochar from whole corn stalk (WCS) and corn stalk pith (CSP) at varying temperatures using potassium hydroxide as the activating agent. ACs were characterized via pore structural analysis and scanning electron microscopy (SEM). These adsorbents were then assessed for their adsorption capacity for butanol vapor. It was found that WCS activated at 900 °C for 1 h (WCS-900) had optimal butanol adsorption characteristics. The BET surface area and total pore volume of the WCS-900 were 2330 m2 g-1 and 1.29 cm3 g-1, respectively. The dynamic adsorption capacity of butanol vapor was 410.0 mg g-1, a 185.1 % increase

  20. Study on Gas Adsorption Equilibrium and Thermodynamics in High/low Temperature Environment%高低温环境下煤对瓦斯的吸附平衡及热力学研究

    Institute of Scientific and Technical Information of China (English)

    岳基伟; 岳高伟; 谢策

    2015-01-01

    The gas adsorption isotherms of three kinds of coal with different metamorphic degree were measured in the high and low temperature environment, the measured data were fitted by Sips model, and the thermodynamic parameters of gas adsorption were calculated and analyzed, including the enthalpy change, the adsorption free energy, entropy change and so on. The research results showed the value γ that represents the coal surface adsorption uniformity decreased linearly with the decrease of the ambient temperature, i. e. the adsorption heterogeneity enhanced; the negative enthalpy change (ΔH) of gas adsorption indicated that the adsorption was exothermic, and with the temperature decrease, the enthalpy change reduced linearly;the curves of the enthalpy change and temperature of the coal with different metamorphic degree intersected at the point where the temperature was 0 ℃( 273. 15 K ); the negative value of the adsorption free energy (ΔG ) indicated that the gas adsorption on coal was a spontaneous process;with the decrease of ambient temperature, the greater the entropy change (ΔS) , the easier the gas adsorption and the larger the gas adsorption amount.%在高低温环境下测定了3种变质程度煤的瓦斯吸附等温线,并通过 Sips 模型进行拟合,同时对瓦斯吸附的焓变、吸附自由能和熵变等热力学参数进行计算分析,研究结果表明:随环境温度降低,煤表面吸附均一性的γ值线性减小,即吸附不均一性增强;吸附焓变(ΔH)为负值,表明吸附是放热的,且焓变随着温度降低线性减小;不同变质程度煤的焓变—温度线交于温度为0 ℃(273. 15 K)的点;吸附自由能(ΔG)为负值,表明甲烷在煤上的吸附过程为自发过程;随环境温度降低,熵变(ΔS)越大,吸附过程越容易进行,瓦斯吸附量也越大.

  1. Acquisition of useful and high ability genes for acidophilic bacteria; Kosansei saikin ni takai noryoku wo fuyosuru idenshi no kakutoku

    Energy Technology Data Exchange (ETDEWEB)

    Senda, T.; Inoue, C.; Shinbori, Y. [Tohoku University, Sendai (Japan)

    1997-02-01

    This effort aims at the development of high-performance bacteria usable in bio-leaching in metal smelting by acquiring genes capable of realizing such. A method is used of choosing some isolated strains exhibiting high-performance traits and acquiring target genes therefrom by use of genetic engineering. Approximately 200 kinds in the aggregate of acidophilic bacteria are currently available for the study, including isolated iron-oxidizing and sulfur-oxidizing bacteria, standard species acquired for the study, and strains previously isolated by the laboratory. The bacteria are tested with respect to their Fe{sup 2+}-oxidizing rates, sulfur-oxidizing capabilities, and strength to withstand inhibiting substances (Ag{sup +}, Cl{sup -}, Mo{sup 6+}, etc.), which results in the nomination of 8 strains. The study planned to follow includes processes involving the extraction of chromosome DNAs from the 8 strains and their refinement, gene cloning by the Southern hybridization method, determination of their base sequences, determination of the difference between the strains in point of gene expression, and investigations of the relations that the results of these processes bear toward the said high-performance traits. Also under way is a study about the infuence-exerting factors revealed during the evaluation of the abilities of acidphlic bacteria. 2 refs., 2 tabs.

  2. Screening of Highly Effective Sinorhizobium meliloti Strains for 'Vector' Alfalfa and Testing of Its Competitive Nodulation Ability in the Field

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhao-Hai; CHEN Wen-Xin; HU Yue-Gao; SUI Xin-Hua; CHEN Dan-Ming

    2007-01-01

    Seventeen Sinorhizobium meliloti strains from seven provinces in China were used to screen highly effective strains for alfalfa cultivar in a greenhouse study and their symbiotic relationship and competitive ability were studied in the field.CCBAU30138 was the most effective strain,as evidenced by increase in dry weights.A field experiment showed that the inoculation of alfalfa with CCBAU30138 resulted in increases of 11.9%and 19.6%of dry matter production and crude protein production,respectively,in forage of monocultured plants.The total dry matter yields of alfalfa and tall fescue in binary culture were increased by 16.3%by inoculation of alfalfa with this strain.These results showed that S.Meliloti strain CCBAU30138 was an effective inoculant both in the greenhouse and in the field.The analysis of randomly amplified polymorphic DNA(RAPD)by polymerase chain reaction(PCR)from nodule extracts showed that the strain CCBAU30138 had high competitiveness in the field.It occupied 47.5%of nodules in alfalfa monoculture and 44.4% of nodules in alfalfa-tall fescue binary culture after 20 weeks of growth.In conclusion,a simple system to select highly effective and competitive symbiotic strains specific to alfalfa was established.Using this system.A strain suitable for the alfalfa cultivar'Vector’grown in Wuqiao County of Hebei Province was obtained.

  3. The Enhancement of Junior High School Students’ Abilities in Mathematical Problem Solving Using Soft Skill-Based Metacognitive Learning

    Directory of Open Access Journals (Sweden)

    Atma Murni

    2013-07-01

    Full Text Available The aim of this study is to know the differences of enhancement inmathematical problem solving ability (MPSA between the studentswho received soft skill- based metacognitive learning (SSML with thestudents who got conventional learning (CL. This research is a quasiexperimental design with pretest-postest control group. The populationin this study is the students of Junior High School in Pekanbaru city.The sample consist of 135 students, 68 of them are from the high-levelschool, and 67 students are from the middle-level school. The instruments are mathematical prior knowledge (MPK test, MPSA test,instruction observation sheet, students journal about the lesson, and the guideline for interview. The data was analyzed using t-test and two way ANOVA. The result of data analysis indicates: (1 overall, theenhancement of students’ MPSA with SSML approach significantly ishigher than those with conventional learning (CL; (2 there is nointeraction between the learning approach (SSML and CL with theschool level (high and middle toward the enhancement of MPSA; (3there is no interaction between the learning approach (SSML and CLwith MPK (upper, middle, and low toward the enhancement of MPSA.

  4. Capability of defective graphene-supported Pd{sub 13} and Ag{sub 13} particles for mercury adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Meeprasert, Jittima; Junkaew, Anchalee; Rungnim, Chompoonut; Kunaseth, Manaschai [National Nanotechnology Center, NSTDA, 111 Thailand Science Park, Klong Luang, Pathum Thani 12120 Thailand (Thailand); Kungwan, Nawee [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Promarak, Vinich [School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210 (Thailand); Namuangruk, Supawadee, E-mail: supawadee@nanotec.or.th [National Nanotechnology Center, NSTDA, 111 Thailand Science Park, Klong Luang, Pathum Thani 12120 Thailand (Thailand)

    2016-02-28

    Graphical abstract: Defective graphene (DG) supported Ag{sub 13} and Pd{sub 13} nanoparticles acts as sorbents for elementary mercury (Hg{sup 0}) adsorption. Hg is inert to DG surface, but it moderately adsorbs on deposited Ag{sub 13}-DG and strongly adsorbs on deposited Pd{sub 13}-DG. - Highlights: • Pd{sub 13}-DG composite has highest stability. • Pd{sub 13}-DG composite is the most reactive sorbent for Hg{sup 0} adsorption. • Hg{sup 0} adsorption abilities of Pd-DG composites are relatively higher than those of Ag-DG composites. • The d-band center of deposited metal is an adsorption descriptor of composite models. - Abstract: Reactivity of single-vacancy defective graphene (DG) and DG-supported Pd{sub n} and Ag{sub n} (n = 1, 13) for mercury (Hg{sup 0}) adsorption has been studied using density functional theory calculation. The results show that Pd{sub n} binds defective site of DG much stronger than the Ag{sub n}, while metal nanocluster binds DG stronger than single metal atom. Metal clustering affects the adsorption ability of Pd composite while that of Ag is comparatively less. The binding strength of −8.49 eV was found for Pd{sub 13} binding on DG surface, indicating its high stability. Analyses of structure, energy, partial density of states, and d-band center (ε{sub d}) revealed that the adsorbed metal atom or cluster enhances the reactivity of DG toward Hg adsorption. In addition, the Hg adsorption ability of M{sub n}-DG composite is found to be related to the ε{sub d} of the deposited M{sub n}, in which the closer ε{sub d} of M{sub n} to the Fermi level correspond to the higher adsorption strength of Hg on M{sub n}-DG composite. The order of Hg adsorption strength on M{sub n}-DG composite are as follows: Pd{sub 13} (−1.68 eV) >> Ag{sub 13} (−0.67 eV) ∼ Ag{sub 1} (−0.69 eV) > Pd{sub 1} (−0.62 eV). Pd{sub 13}-DG composite is therefore more efficient sorbent for Hg{sup 0} removal in terms of high stability and high adsorption

  5. The Development of Learning Devices Based Guided Discovery Model to Improve Understanding Concept and Critical Thinking Mathematically Ability of Students at Islamic Junior High School of Medan

    Science.gov (United States)

    Yuliani, Kiki; Saragih, Sahat

    2015-01-01

    The purpose of this research was to: 1) development of learning devices based guided discovery model in improving of understanding concept and critical thinking mathematically ability of students at Islamic Junior High School; 2) describe improvement understanding concept and critical thinking mathematically ability of students at MTs by using…

  6. Emotion Perception Mediates the Predictive Relationship between Verbal Ability and Functional Outcome in High-Functioning Adults with Autism Spectrum Disorder

    Science.gov (United States)

    Otsuka, Sadao; Uono, Shota; Yoshimura, Sayaka; Zhao, Shuo; Toichi, Motomi

    2017-01-01

    The aim of this study was to identify specific cognitive abilities that predict functional outcome in high-functioning adults with autism spectrum disorder (ASD), and to clarify the contribution of those abilities and their relationships. In total, 41 adults with ASD performed cognitive tasks in a broad range of neuro- and social cognitive…

  7. Adsorption and Desorption of Methiopyrsulfuron in Soils

    Institute of Scientific and Technical Information of China (English)

    WU Chun-Xian; WANG Jin-Jun; ZHANG Su-Zhi; ZHANG Zhong-Ming

    2011-01-01

    Methiopyrsulfuron is a new low-rate sulfonylurea herbicide for weed control in wheat; however, there is a lack of published information on its behavior in soils. In this study, methiopyrsulfuron adsorption and desorption were measured in seven soils sampled from Heilongjiang, Shandong, Jiangxi, Sichuan, Anhui, and Chongqing provinces of China using a batch equilibrium method. The Freundlich equation was used to described its adsorption and desorption. Adsorption isotherms were nonlinear with the values of Kf-ads, the Freundlich empirical constant indicative of the adsorption capacity,ranging from 0.75 to 2.46, suggesting that little of this herbicide was adsorbed by any of the seven soils. Soil pH and organic matter content (OM) were the main factors influencing adsorption; adsorption was negatively correlated with pH and positively correlated with OM. Methiopyrsulfuron desorption was hysteretic on the soils with high OM content and low pH.

  8. Generation of highly reactive oxygen species by co-adsorption of oxygen and water on metal-supported MgO(100) thinfilms

    CERN Document Server

    Song, Zhenjun

    2015-01-01

    The formation of highly reactive oxygen species (ROS) on metal oxide surfaces have attracted considerable interest due to their diverse applications. In this work, we have performed densi-ty-functional theory calculations to investigate the co-adsorption of oxygen and water on ul-trathin MgO(100) films deposited on Mo(100) substrate. We reveal that the molecular oxygen can be stepwise decomposed completely with the assistance of water. Consequently, a series of highly ROS including superoxide, hydroperoxide, hydroxyl and single oxygen adatom are formed on Mo(100) supported MgO(100) thinfilms. The reaction barriers accompanied by the generation of ROS are reported, and the influence of the thickness of MgO(100) films is also discussed. The most promising routes to produce these fascinating species provide valuable information to understand the importance of synergistic effect, namely the substrate, the co-adorbed species, and the film thickness, in multiphase catalyst design.

  9. An Efficient Pd-Sn Catalyst Supported on MWNTs for Hydrogenation of High Concentrated Acetylene Feedstocks: The Potential Role of Isolated Adsorption Site

    Directory of Open Access Journals (Sweden)

    E. Esmaeili

    2014-04-01

    Full Text Available In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and Sn which contained a high percentage of ordered intermetallic structures (70.8%, as confirmed by XPS. According to the results, pore blocking and/or fouling was known as the main reasons of the catalyst deactivation. Here, we supposed a novel deactivation mechanism based on which dehydrogenation susceptibility of carbonaceous species (green oil played a significant role in the formation of the isolated adsorption sites and then, catalyst deactivation.

  10. Influence of Main Components in Exhaust Gas on Mercury Adsorption Capacity of Brominated Activated Carbon

    Directory of Open Access Journals (Sweden)

    Tran Hong Con

    2016-01-01

    Full Text Available Brominated activated carbon (AC-Br, which was produced from coconut shell activated carbon (AC and brominated by wet way with elemental bromine, was determined as a material with super high adsorption capacity of mercury vapor. But in real exhaust gases, there are many components such as SO2, NOx, CO, CO2, HCl, H2O can influence on adsorption ability of the AC-Br. In this paper, these influences were studied and compared them between initial AC and AC-Br. Each component has different effect on AC and AC-Br and followed by its particular mechanism.

  11. Mathematics Instructional Model Based on Realistic Mathematics Education to Promote Problem Solving Ability at Junior High School Padang

    Directory of Open Access Journals (Sweden)

    Edwin Musdi

    2016-02-01

    Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase.  At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.

  12. Percent voluntary inactivation and peak force predictions with the interpolated twitch technique in individuals with high ability of voluntary activation.

    Science.gov (United States)

    Herda, Trent J; Walter, Ashley A; Costa, Pablo B; Ryan, Eric D; Hoge, Katherine M; Stout, Jeffrey R; Cramer, Joel T

    2011-10-01

    The purpose of this study was to examine the sensitivity and peak force prediction capability of the interpolated twitch technique (ITT) performed during submaximal and maximal voluntary contractions (MVCs) in subjects with the ability to maximally activate their plantar flexors. Twelve subjects performed two MVCs and nine submaximal contractions with the ITT method to calculate percent voluntary inactivation (%VI). Additionally, two MVCs were performed without the ITT. Polynomial models (linear, quadratic and cubic) were applied to the 10-90% VI and 40-90% VI versus force relationships to predict force. Peak force from the ITT MVC was 6.7% less than peak force from the MVC without the ITT. Fifty-eight percent of the 10-90% VI versus force relationships were best fit with nonlinear models; however, all 40-90% VI versus force relationships were best fit with linear models. Regardless of the polynomial model or the contraction intensities used to predict force, all models underestimated the actual force from 22% to 28%. There was low sensitivity of the ITT method at high contraction intensities and the predicted force from polynomial models significantly underestimated the actual force. Caution is warranted when interpreting the % VI at high contraction intensities and predicted peak force from submaximal contractions.

  13. Mathematics Instructional Model Based on Realistic Mathematics Education to Promote Problem Solving Ability at Junior High School Padang

    Directory of Open Access Journals (Sweden)

    Edwin Musdi

    2016-02-01

    Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase.  At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.

  14. TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

    Science.gov (United States)

    Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

    2015-01-01

    A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

  15. Stability of Fluorosurfactant Adsorption on Mineral Surface for Water Removal in Tight Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Lijun You

    2015-01-01

    Full Text Available Long-term effectiveness of rock wettability alteration for water removal during gas production from tight reservoir depends on the surfactant adsorption on the pore surface of a reservoir. This paper selected typical cationic fluorosurfactant FW-134 as an example and took advantage of Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS, and atomic force microscope (AFM to investigate its adsorption stability on the rock mineral surface under the oscillation condition at high temperature for a long time. The experimental results indicate that the F element content on the sample surface increases obviously, the surface structure of fluorine-carbonization also undergoes a significant change, and the fluorine surfactant exhibits a good interfacial modification and wettability alteration ability due to its adsorption on the pore surface transforming the chemical structure of the original surface. The adsorption increases indistinctly with the concentration of over 0.05% due to a single layer adsorption structure and is mainly electrostatic adsorption because the chemical bonding between the fluorosurfactant and the rock mineral surface, the hydrogen bonding, is weak and inconspicuous.

  16. Adsorption properties of an activated carbon for 18 cytokines and HMGB1 from inflammatory model plasma.

    Science.gov (United States)

    Inoue, Satoru; Kiriyama, Kentaro; Hatanaka, Yoshihiro; Kanoh, Hirofumi

    2015-02-01

    The ability of an activated carbon (AC) to adsorb 18 different cytokines with molecular weights ranging from 8 kDa to 70 kDa and high mobility group box-1 (HMGB1) from inflammatory model plasma at 310 K and the mechanisms of adsorption were examined. Porosity analysis using N2 gas adsorption at 77K showed that the AC had micropores with diameters of 1-2 nm and mesopores with diameters of 5-20 nm. All 18 cytokines and HMGB1 were adsorbed on the AC; however, the shapes of the adsorption isotherms changed depending on the molecular weight. The adsorption isotherms for molecules of 8-10 kDa, 10-20 kDa, 20-30 kDa, and higher molecular weights were classified as H-2, L-3, S-3, and S-1 types, respectively. These results suggested that the adsorption mechanism for the cytokines and HMGB1 in the mesopores and on the surface of the AC differed as a function of the molecular weight. On the basis of these results, it can be concluded that AC should be efficient for cytokine adsorption.

  17. Adsorption and collective paramagnetism

    CERN Document Server

    Selwood, Pierce W

    1962-01-01

    Adsorption and Collective Paramagnetism describes a novel method for studying chemisorption. The method is based on the change in the number of unpaired electrons in the adsorbent as chemisorption occurs. The method is applicable to almost all adsorbates, but it is restricted to ferromagnetic adsorbents such as nickel, which may be obtained in the form of very small particles, that is to say, to ferromagnetic adsorbents with a high specific surface. While almost all the data used illustratively have been published elsewhere this is the first complete review of the subject. The book is addresse

  18. Theoretical investigation of CO adsorption on TM-doped (MgO){sub 12} (TM = Ni, Pd, Pt) nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yang Mingxia [Division of Molecule and Materials Simulation, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang Yonghong [Dept. of Applied Physics, Tianjin Polytechnic University, Tianjin 300160 (China); Huang Shiping, E-mail: huangsp@mail.buct.edu.cn [Division of Molecule and Materials Simulation, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Liu Hui [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Peng; Tian Huiping [Research Institute of Petroleum Processing, SINOPEC, Beijing 100083 (China)

    2011-12-01

    CO adsorption on TM-doped magnesia nanotubes (TM = Ni, Pd and Pt) have been studied by using density functional theory. Our calculation results show that CO favors adsorption on TM-doped magnesia nanotubes in the form of C atom bonding with TM atom. Fukui indices analysis clearly exhibits that doping of impurity TM atom allows for a noticeably enhancement of nucleophilic reactivity ability of magnesia nanotube. The adsorption energies demonstrate that CO molecule is more strongly bound on the 3-fold TM atoms than the 4-fold TM atoms. This finding is well confirmed by TM-C bond length, charge transfer and C-O vibrational frequency. The high adsorption energy of 2.55 eV is found when CO adsorbs on 3-fold Pt in Pt-doped magnesia nanotubes, implying the kind of the doping TM atom has a significant influence on the chemical reactivity.

  19. Adsorption and photocatalytic degradation of bisphenol A using TiO2 and its separation by submerged hollowfiber ultrafiltration membrane

    Institute of Scientific and Technical Information of China (English)

    Jae-Wook Lee; Tae-Ouk Kwon; Ramesh Thiruvenkatachari; Il-Shik Moon

    2006-01-01

    This study evaluates the adsorption ability of bisphenol A(BPA) on titanium dioxide(TiO2) and its effect on the photocatalysis by advanced oxidation process using UV radiation and TiO2 photocatalyst. Degradation of BPA was also evaluated for the system without adsorption prior to photocatalytic reaction. The separation of TiO2 from BPA solution treated by pilot-scale photocatalytic reactor (capacity 0.16 m3) was studied using submerged ultrafiltration (UF) membrane. It was found that although adsorption capacity of BPA was not high, adsorption played an important role in improving the efficiency ofphotocatalysis. On the other hand, during the separation of TiO2 particles from aqueous suspension, the permeate flux of the membrane was strongly affected by transmembrane pressure and TiO2 dose. The permeate turbidity was decreased below 1 NTU.

  20. Hydrogen adsorption and diffusion, and subcritical-crack growth in high-strength steels and nickel base alloys

    Science.gov (United States)

    Wei, R. P.; Klier, K.; Simmons, G. W.

    1974-01-01

    Coordinated studies of the kinetics of crack growth and of hydrogen adsorption and diffusion were initiated to develop information that is needed for a clearer determination of the rate controlling process and possible mechanism for hydrogen enhanced crack growth, and for estimating behavior over a range of temperatures and pressures. Inconel 718 alloy and 18Ni(200) maraging steel were selected for these studies. 18Ni(250) maraging steel, 316 stainless steel, and iron single crystal of (111) orientation were also included in the chemistry studies. Crack growth data on 18Ni(250) maraging steel from another program are included for comparison. No sustained-load crack growth was observed for the Inconel 718 alloy in gaseous hydrogen. Gaseous hydrogen assisted crack growth in the 18Ni maraging steels were characterized by K-independent (Stage 2) extension over a wide range of hydrogen pressures (86 to 2000 torr or 12 kN/m2 to 266 kN/m2) and test temperatures (-60 C to +100 C). The higher strength 18Ni(250) maraging steel was more susceptible than the lower strength 200 grade. A transition temperature was observed, above which crack growth rates became diminishingly small.