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Sample records for learning activities mn

  1. Preliminary Experiment on Neutron-Induced Mn Activity in Mn-Cd Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Broda, E.

    1942-07-01

    This report was written by E. Broda, J. Gueron and L. Kowarski at the Cavendish Laboratory (Cambridge) in June 1942 and is about a preliminary experiment on neutron-induced Mn activity in Mn-Cd solutions. The description of the experiment and the results can be found also in this report. (nowak)

  2. Nano-sized Mn3O4 and β-MnOOH from the decomposition of β-cyclodextrin-Mn: 2. The water-oxidizing activities.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Mostafalu, Ramin; Hołyńska, Małgorzata; Ebrahimi, Foad; Kaboudin, Babak

    2015-11-01

    Nano-sized Mn oxides contain Mn3O4, β-MnOOH and Mn2O3 have been prepared by a previously reported method using thermal decomposition of β-cyclodextrin-Mn complexes. In the next step, the water-oxidizing activities of these Mn oxides using cerium(IV) ammonium nitrate as a chemical oxidant are studied. The turnover frequencies for β-MnO(OH) and Mn3O4 are 0.24 and 0.01-0.17 (mmol O2/mol Mns), respectively. Subsequently, water-oxidizing activities of these compounds are compared to the other previously reported Mn oxides. Important factors affecting water oxidation by these Mn oxides are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Oxidative and antibacterial activity of Mn3O4

    International Nuclear Information System (INIS)

    Chowdhury, Al-Nakib; Azam, Md. Shafiul; Aktaruzzaman, Md.; Rahim, Abdur

    2009-01-01

    Mn 3 O 4 nanoparticles with diameter ca. 10 nm were synthesized by the forced hydrolysis of Mn(II) acetate at 80 deg. C. The X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques were employed to study structural features and chemical composition of the nanoparticles. The unique oxidative activity of the Mn 3 O 4 nanoparticles was demonstrated in the polymerization and dye degradation reactions. On adding Mn 3 O 4 suspension to an acidic solution of aniline, yielded immediately green sediment of polyaniline (PANI). The organic dyes, viz., methylene blue (MB) and procion red (PR) were found to be completely decolorized from their aqueous solution on treating the dyes with Mn 3 O 4 suspension in acidic media. The Mn 3 O 4 nanoparticles also showed a clear antibacterial activity against the Vibrio cholerae, Shigella sp., Salmonella sp., and Escherichi coli bacteria that cause cholera, dysentery, typhoid, and diarrhea diseases, respectively.

  4. The influence of Mn species on the SO{sub 2} removal of Mn-based activated carbon catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Yi-Fan [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Chu, Ying-Hao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Sun, Ming-Chao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Yin, Hua-Qiang, E-mail: hqyin@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China)

    2013-10-01

    Using Mn(NO{sub 3}){sub 2} as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO{sub 2} were investigated. MnO and Mn{sub 3}O{sub 4} coexist in catalysts calcined at 650 and 800 °C and exhibit best SO{sub 2} removal ability, whereas Mn{sub 2}O{sub 3} formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO{sub 2}. And this change directly results in a decrease of activity. But the SO{sub 2} removal rate has been maintained in the range of 30–40%, indicating that MnO{sub 2} still has a certain SO{sub 2} removal ability.

  5. The influence of Mn species on the SO2 removal of Mn-based activated carbon catalysts

    International Nuclear Information System (INIS)

    Qu, Yi-Fan; Guo, Jia-Xiu; Chu, Ying-Hao; Sun, Ming-Chao; Yin, Hua-Qiang

    2013-01-01

    Using Mn(NO 3 ) 2 as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO 2 were investigated. MnO and Mn 3 O 4 coexist in catalysts calcined at 650 and 800 °C and exhibit best SO 2 removal ability, whereas Mn 2 O 3 formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO 2 . And this change directly results in a decrease of activity. But the SO 2 removal rate has been maintained in the range of 30–40%, indicating that MnO 2 still has a certain SO 2 removal ability.

  6. Interpretable Active Learning

    OpenAIRE

    Phillips, Richard L.; Chang, Kyu Hyun; Friedler, Sorelle A.

    2017-01-01

    Active learning has long been a topic of study in machine learning. However, as increasingly complex and opaque models have become standard practice, the process of active learning, too, has become more opaque. There has been little investigation into interpreting what specific trends and patterns an active learning strategy may be exploring. This work expands on the Local Interpretable Model-agnostic Explanations framework (LIME) to provide explanations for active learning recommendations. W...

  7. Active Learning Methods

    Science.gov (United States)

    Zayapragassarazan, Z.; Kumar, Santosh

    2012-01-01

    Present generation students are primarily active learners with varied learning experiences and lecture courses may not suit all their learning needs. Effective learning involves providing students with a sense of progress and control over their own learning. This requires creating a situation where learners have a chance to try out or test their…

  8. From learning objects to learning activities

    DEFF Research Database (Denmark)

    Dalsgaard, Christian

    2005-01-01

    This paper discusses and questions the current metadata standards for learning objects from a pedagogical point of view. From a social constructivist approach, the paper discusses how learning objects can support problem based, self-governed learning activities. In order to support this approach......, it is argued that it is necessary to focus on learning activities rather than on learning objects. Further, it is argued that descriptions of learning objectives and learning activities should be separated from learning objects. The paper presents a new conception of learning objects which supports problem...... based, self-governed activities. Further, a new way of thinking pedagogy into learning objects is introduced. It is argued that a lack of pedagogical thinking in learning objects is not solved through pedagogical metadata. Instead, the paper suggests the concept of references as an alternative...

  9. Theoretical Foundations of Active Learning

    Science.gov (United States)

    2009-05-01

    I study the informational complexity of active learning in a statistical learning theory framework. Specifically, I derive bounds on the rates of...convergence achievable by active learning , under various noise models and under general conditions on the hypothesis class. I also study the theoretical...advantages of active learning over passive learning, and develop procedures for transforming passive learning algorithms into active learning algorithms

  10. Effects of Mn- and K-addition on catalytic activity of calcium oxide for methane activation

    International Nuclear Information System (INIS)

    Park, Jong Sik; Kong, Jang Il; Lee, Sung Han; Jun, Jong Ho

    1998-01-01

    Pure CaO, Mn-doped CaO, Mn/CaO, and K/CaO catalysts were prepared and tested as catalysts for the oxidative coupling of methane in the temperature range of 600 to 800 .deg. C to investigate the effects of Mn- and K-addition on the catalytic activity of calcium oxide. To characterize the catalysts, X-ray powder diffraction (XRD), XPS, SEM, DSC, and TG analyses were performed. The catalytic reaction was carried out in a single-pass flow reactor using on-line gas chromatography system. Normalized reaction conditions were generally p(CH 4 )/p(O 2 )=250 Torr/50 Torr, total feed flow rate=30 mL/min, and 1 atm of total pressure with He being used as diluent gas. Among the catalysts tested, 6.3 mol% Mn-doped CaO catalyst showed the best C 2 yield of 8.0% with a selectivity of 43.2% at 775 .deg. C. The C 2 selectivity increased on lightly doped CaO catalysts, while decreased on heavily doped CaO((Mn)>6.3 mol%)catalysts. 6 wt.% Mn/CaO and 6 wt.% K/CaO catalysts showed the C 2 selectivities of 13.2% and 30.9%, respectively, for the reaction. Electrical conductivities of CaO and Mn-doped CaO were measured in the temperature range of 500 to 1000 .deg. C at Po2's of 10 -3 to 10 -1 atm. The electrical conductivity was decreased with Mn-doping and increased with increasing Po 2 in the range of 10 -3 to 10 -1 atm, indicating the specimens to be p-type semiconductors. It was suggested that the interstitial oxygen ions formed near the surface can activate methane and the formation of interstitial oxygen ions was discussed on the basis of solid-state chemistry

  11. Minimax bounds for active learning

    NARCIS (Netherlands)

    Castro, R.M.; Nowak, R.

    2008-01-01

    This paper analyzes the potential advantages and theoretical challenges of "active learning" algorithms. Active learning involves sequential sampling procedures that use information gleaned from previous samples in order to focus the sampling and accelerate the learning process relative to "passive

  12. Active Math Learning

    DEFF Research Database (Denmark)

    The presentation is concerned with general course planning philosophy and a specific case study (boomerang flight geometro-dynamics) for active learning of mathematics via computer assisted and hands-on unfolding of first principles - in this case the understanding of rotations and Eulers equatio...

  13. Flipped Classroom, active Learning?

    DEFF Research Database (Denmark)

    Andersen, Thomas Dyreborg; Levinsen, Henrik; Philipps, Morten

    2015-01-01

    Action research is conducted in three physics classes over a period of eighteen weeks with the aim of studying the effect of flipped classroom on the pupils agency and learning processes. The hypothesis is that flipped classroom teaching will potentially allocate more time to work actively...

  14. Learning Activity Package, Algebra.

    Science.gov (United States)

    Evans, Diane

    A set of ten teacher-prepared Learning Activity Packages (LAPs) in beginning algebra and nine in intermediate algebra, these units cover sets, properties of operations, number systems, open expressions, solution sets of equations and inequalities in one and two variables, exponents, factoring and polynomials, relations and functions, radicals,…

  15. Grooming. Learning Activity Package.

    Science.gov (United States)

    Stark, Pamela

    This learning activity package on grooming for health workers is one of a series of 12 titles developed for use in health occupations education programs. Materials in the package include objectives, a list of materials needed, information sheets, reviews (self evaluations) of portions of the content, and answers to reviews. These topics are…

  16. Simultaneous determination of 56 Mn and 187W in neutron activated steels

    International Nuclear Information System (INIS)

    Melo, M.C. de

    1982-01-01

    The simultaneous determination of the count rates due to 56 Mn and 187 W in the activation analysis of steel samples was carried out through exponential regression using least square fitting. The regression coefficients obtained corresponded to the initial count rates of 56 Mn and 187 W. Later on, the count rates of 56 Mn were correlated to the manganese content in the samples and to the count rates of the same radionuclide, obtained in a region of the gamma spectrum where only 56 Mn was apparent. The correlation coefficients were respectively .968 and .99997, thus demonstrating the applicability of the methodology adopted herein. (Author) [pt

  17. Active Learning Using Hint Information.

    Science.gov (United States)

    Li, Chun-Liang; Ferng, Chun-Sung; Lin, Hsuan-Tien

    2015-08-01

    The abundance of real-world data and limited labeling budget calls for active learning, an important learning paradigm for reducing human labeling efforts. Many recently developed active learning algorithms consider both uncertainty and representativeness when making querying decisions. However, exploiting representativeness with uncertainty concurrently usually requires tackling sophisticated and challenging learning tasks, such as clustering. In this letter, we propose a new active learning framework, called hinted sampling, which takes both uncertainty and representativeness into account in a simpler way. We design a novel active learning algorithm within the hinted sampling framework with an extended support vector machine. Experimental results validate that the novel active learning algorithm can result in a better and more stable performance than that achieved by state-of-the-art algorithms. We also show that the hinted sampling framework allows improving another active learning algorithm designed from the transductive support vector machine.

  18. Active Learning with Statistical Models.

    Science.gov (United States)

    1995-01-01

    Active Learning with Statistical Models ASC-9217041, NSF CDA-9309300 6. AUTHOR(S) David A. Cohn, Zoubin Ghahramani, and Michael I. Jordan 7. PERFORMING...TERMS 15. NUMBER OF PAGES Al, MIT, Artificial Intelligence, active learning , queries, locally weighted 6 regression, LOESS, mixtures of gaussians...COMPUTATIONAL LEARNING DEPARTMENT OF BRAIN AND COGNITIVE SCIENCES A.I. Memo No. 1522 January 9. 1995 C.B.C.L. Paper No. 110 Active Learning with

  19. Improvement of the photocatalytic activity of magnetite by Mn-incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Hudson W.P., E-mail: hudsonwpc@yahoo.com.br; Hammer, Peter, E-mail: peter@iq.unesp.br; Pulcinelli, Sandra H., E-mail: sandrap@iq.unesp.br; Santilli, Celso V., E-mail: santilli@iq.unesp.br; Molina, Eduardo F., E-mail: efmolina@iq.unesp.br

    2014-02-15

    Highlights: • Efficiently methylene blue dye discoloration using an Mn doped magnetite catalyst. • Evidence for isomorphic substitution of Fe{sup 2+} by Mn{sup 2+} in the octahedral structure. • Mechanism of the enhanced photocatalysis induced by active Mn sites. • Importance of the Mn reaction rate constant and effective surface area. -- Abstract: Mn-incorporated Fe{sub 3}O{sub 4} photocatalysts were prepared by a simple co-precipitation method. Photocatalytic discoloration of Methylene Blue (MB) was used to evaluate the performance of these catalysts. The DSC results have shown that the insertion of Mn into Fe{sub 3}O{sub 4} lattice has increased converting Fe{sub 3}O{sub 4} to γ-Fe{sub 2}O{sub 3}. This is accompanied by a decrease of surface area and of crystallinity, as detected by XRD. The analysis of the chemical environment by XPS has shown that Mn{sup 2+} replaces Fe{sup 2+} preferentially in the octahedral sites while Mn{sup 3+} replaces Fe{sup 3+} of inverse spinel sites. The Mn-incorporated samples were significantly more efficient in MB discoloration assisted by UVA irradiation and H{sub 2}O{sub 2}. It was also found that ascorbic acid prevents H{sub 2}O{sub 2} decomposition, by scavenging preferentially ·OOH radicals produced at Mn sites. Finally, the results reported here can contribute for a better comprehension of the activity of composite catalysts and the design of efficient systems for discoloration of organic pollutants.

  20. Active inference and learning.

    Science.gov (United States)

    Friston, Karl; FitzGerald, Thomas; Rigoli, Francesco; Schwartenbeck, Philipp; O Doherty, John; Pezzulo, Giovanni

    2016-09-01

    This paper offers an active inference account of choice behaviour and learning. It focuses on the distinction between goal-directed and habitual behaviour and how they contextualise each other. We show that habits emerge naturally (and autodidactically) from sequential policy optimisation when agents are equipped with state-action policies. In active inference, behaviour has explorative (epistemic) and exploitative (pragmatic) aspects that are sensitive to ambiguity and risk respectively, where epistemic (ambiguity-resolving) behaviour enables pragmatic (reward-seeking) behaviour and the subsequent emergence of habits. Although goal-directed and habitual policies are usually associated with model-based and model-free schemes, we find the more important distinction is between belief-free and belief-based schemes. The underlying (variational) belief updating provides a comprehensive (if metaphorical) process theory for several phenomena, including the transfer of dopamine responses, reversal learning, habit formation and devaluation. Finally, we show that active inference reduces to a classical (Bellman) scheme, in the absence of ambiguity. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Re-imagining Active Learning

    DEFF Research Database (Denmark)

    Dall'Alba, Gloria; Bengtsen, Søren Smedegaard

    2018-01-01

    is largely lacking in the literature on active learning. In this article, we explore the possibility of re-imagining, or at least extending, the meaning of active learning by drawing out dimensions that are neither readily visible nor instrumental, as much of this literature implies. Drawing from educational......Ample attention is being paid in the higher education literature to promoting active learning among students. Where studies on active learning report student outcomes, they indicate improved or equivalent outcomes when compared with traditional lectures, which are considered more passive...... philosophy and, in particular, existential philosophies, we argue that active learning may also be partly invisible, unfocused, unsettling, and not at all instrumentalsometimes even leaving the learner more confused and (temporarily) incompetent. However, such forms of undisclosed or ‘dark’ learning, we...

  2. Comparative Study on Adsorption of Mn(II from Aqueous Solutions on Various Activated Carbons

    Directory of Open Access Journals (Sweden)

    K. A. Emmanuel

    2009-01-01

    Full Text Available The adsorption of Mn(II on indigenously prepared activated carbons (IPAC from Bombax malabaricum, Pithecelobium dulse, Ipomea batatas and Peltaforum ferraginium have been studied. The effects of various experimental parameters have been investigated using batch adsorption technique. The extent of Mn(II removal increased with decrease in initial concentration of the Mn(II, particle size of the adsorbent and increased with increase in contact time, amount of adsorbent used and the initial pH of the solution. Adsorption data were modeled using Freundlich and Langmuir adsorption isotherms and first order kinetic equations. The kinetics of adsorption was found to be first order with regard to intra-particle diffusion rate. The results indicate that such carbons could be employed as low cost adsorbents in waste water treatment for the removal of Mn(II.

  3. Fe and Mn levels regulated by agricultural activities in alluvial groundwaters underneath a flooded paddy field

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kangjoo [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of)], E-mail: kangjoo@kunsan.ac.kr; Kim, Hyun-Jung; Choi, Byoung-Young; Kim, Seok-Hwi; Park, Ki-hoon [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of); Park, Eungyu [Department of Geology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Koh, Dong-Chan [Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Yun, Seong-Taek [Department of Earth and Environmental Sciences, Korea University, Seoul 136-701 (Korea, Republic of)

    2008-01-15

    Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO{sub 4} concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO{sub 4}, supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO{sub 3} at shallow depths and by SO{sub 4} reduction at the greater depths. Isotopic and mass balance analyses revealed that NO{sub 3} and SO{sub 4} in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area.

  4. Oxidative and antibacterial activity of Mn{sub 3}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Al-Nakib, E-mail: nakib@chem.buet.ac.bd [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Azam, Md. Shafiul, E-mail: azam@ualberta.ca [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Aktaruzzaman, Md.; Rahim, Abdur [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh)

    2009-12-30

    Mn{sub 3}O{sub 4} nanoparticles with diameter ca. 10 nm were synthesized by the forced hydrolysis of Mn(II) acetate at 80 deg. C. The X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques were employed to study structural features and chemical composition of the nanoparticles. The unique oxidative activity of the Mn{sub 3}O{sub 4} nanoparticles was demonstrated in the polymerization and dye degradation reactions. On adding Mn{sub 3}O{sub 4} suspension to an acidic solution of aniline, yielded immediately green sediment of polyaniline (PANI). The organic dyes, viz., methylene blue (MB) and procion red (PR) were found to be completely decolorized from their aqueous solution on treating the dyes with Mn{sub 3}O{sub 4} suspension in acidic media. The Mn{sub 3}O{sub 4} nanoparticles also showed a clear antibacterial activity against the Vibrio cholerae, Shigella sp., Salmonella sp., and Escherichi coli bacteria that cause cholera, dysentery, typhoid, and diarrhea diseases, respectively.

  5. Fe and Mn levels regulated by agricultural activities in alluvial groundwaters underneath a flooded paddy field

    International Nuclear Information System (INIS)

    Kim, Kangjoo; Kim, Hyun-Jung; Choi, Byoung-Young; Kim, Seok-Hwi; Park, Ki-hoon; Park, Eungyu; Koh, Dong-Chan; Yun, Seong-Taek

    2008-01-01

    Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO 4 concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO 4 , supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO 3 at shallow depths and by SO 4 reduction at the greater depths. Isotopic and mass balance analyses revealed that NO 3 and SO 4 in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area

  6. Efficient activation of peroxymonosulfate by magnetic Mn-MGO for degradation of bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiangkun [School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Bao, Jianguo, E-mail: bjianguo@cug.edu.cn [School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Liu, Ying; Ling, Haibo; Zheng, Han [School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Kim, Sang Hoon, E-mail: kim_sh@kist.re.kr [Center for Materials Architecturing, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States)

    2016-12-15

    Highlights: Manganese catalyst was immobilized on Fe{sub 3}O{sub 4}/graphene hybrids to facilitate magnetic separation. Magnetic manganese catalyst exhibited high efficacy and long-term stability for catalytic PMS activation. The minerlization efficiency and the biotoxicity of BPA byproducts were evaluated. The degradation pathways of BPA and the possible activation mechanism of PMS were proposed. - Abstract: A heterogeneous manganese/magnetite/graphene oxide (Mn-MGO) hybrid catalyst was fabricated through the reduction of KMnO{sub 4} by ethylene glycol in the presence of magnetite/GO (MGO) particles. The Mn-MGO catalyst exhibited high efficacy and long-term stability in activating peroxymonosulfate (PMS) to generate sulfate radicals for the removal of bisphenol A (BPA) from water. The results of the batch experiments indicated that an increase in the catalyst dose and solution pH could enhance BPA degradation in the coupled Mn-MGO/PMS system. Regardless of the initial pH, the solution pH significantly dropped after the reaction, which was caused by catalytic PMS activation. The production of sulfate radicals and hydroxyl radicals was validated through radical quenching and electron paramagnetic resonances (EPR) tests. BPA degradation pathways were proposed on the basis of LC-MS and GC-MS analyses. Finally, a possible mechanism of catalytic PMS activation was proposed that involved electron transfer from MnO or Mn{sub 2}O{sub 3} to PMS with the generation of sulfate radicals, protons and MnO{sub 2}, as well as the simultaneous reduction of MnO{sub 2} by PMS.

  7. Student Perceptions of Active Learning

    Science.gov (United States)

    Lumpkin, Angela; Achen, Rebecca M.; Dodd, Regan K.

    2015-01-01

    A paradigm shift from lecture-based courses to interactive classes punctuated with engaging, student-centered learning activities has begun to characterize the work of some teachers in higher education. Convinced through the literature of the values of using active learning strategies, we assessed through an action research project in five college…

  8. Activity of Mn-Oxidizing Peroxidases of Ganoderma lucidum Depending on Cultivation Conditions

    Directory of Open Access Journals (Sweden)

    Jasmina Ćilerdžić

    2015-11-01

    Full Text Available Trunks and stumps of various deciduous species act as natural habitats for Ganoderma lucidum. The chemical composition of their cell wall affects the development of fungal ligninolytic enzyme system as well as its ability to degrade lignin from the plant cell wall. Additionally, numerous compounds structurally similar to lignin can be degraded by the G. lucidum enzyme system which could take important roles in various biotechnological processes. The laccases, which are the dominant enzymes synthesized by G. lucidum, have been studied more extensively than the Mn-oxidizing peroxidases. Therefore, this study aimed to create the dynamics profile of Mn-oxidizing peroxidases activities in four G. lucidum strains, classifying and determining their properties depending on the cultivation type and plant residue as a carbon source in the medium, as well as to establish whether intraspecific variety exists. The findings suggest that submerged cultivation appeared to be a more appropriate cultivation type for enzyme activities compared with solid-state cultivation, and oak sawdust was a better carbon source than wheat straw. Under the optimum conditions, on day 14, G. lucidum BEOFB 431 was characterized by the highest levels of both Mn-dependent and Mn-independent peroxidase activities (4795.5 and 5170.5 U/L, respectively. Strain, cultivation type, and carbon source were factors that affected the profiles of Mn-oxidizing peroxidases isoenzymes.

  9. Learning and Active Aging

    Science.gov (United States)

    Boulton-Lewis, Gillian M.; Buys, Laurie; Lovie-Kitchin, Jan

    2006-01-01

    Learning is an important aspect of aging productively. This paper describes results from 2645 respondents (aged from 50 to 74+ years) to a 165-variable postal survey in Australia. The focus is on learning and its relation to work; social, spiritual, and emotional status; health; vision; home; life events; and demographic details. Clustering…

  10. Effect of plant species on the specific activity of 65Zn and 54Mn

    International Nuclear Information System (INIS)

    Muraoka, T.; Neptune, A.M.L.

    1983-01-01

    The effect of five plant species on the specific activity of 65 Zn and 54 Mn is studied. Soybean (Glycine max (L.) Merril), bean (Phaseolus vulgaris, L.), rice (Oryza sativa, L.), wheat (Triticum aestivum, L.) and tomato (Lycopersium esculentum Mill) were grown in PV and TE soils labelled with 65 Zn and 54 Mn. The plants were harvested 30 days after seeding and specific activities of zinco and manganese were determined in the above ground part and in the roots. (M.A.C.) [pt

  11. Competition of the self-activated and Mn-related luminescence in ZnS single crystals

    Science.gov (United States)

    Bacherikov, Yu. Yu.; Vorona, I. P.; Markevich, I. V.; Korsunska, N. O.; Kurichka, R. V.

    2018-06-01

    The photoluminescence (PL) and photoluminescence excitation (PLE) spectra of ZnS single crystals thermally doped from ZnS/MnS mixture were studied at 300 and 77 K. PL spectra exhibit bands caused by Mn-related centers and centers of self-activated (SA) emission. Besides intrinsic maximum, a number of narrow peaks corresponded to Mn-related absorption are found in the PLE spectra of both SA and Mn-related emission. A redistribution of SA and Mn-related emission intensities is observed with temperature change. The mechanism of this phenomenon involving free hole trapping by MnZn and the possible position of a ground energy level of substitutional Mn are discussed.

  12. Study of bioavailability of Mn in soil manured with bio solids using neutron activation analysis (NAA)

    International Nuclear Information System (INIS)

    Mateus, Natalina de Fatima; Madi Filho, Tufic

    2010-01-01

    Full text: This work evaluated, using neutron activation analysis (NAA), the behavior of Mn absorption by Eucalyptus manured with bio solids. Manganese is an important micro nutrient because it is an activator of enzymes, controller of oxy reduction reactions, essential to the photosynthesis and synthesis of chlorophyll and protein. Its lack causes a decrease in photosynthesis, which reduces growth and productivity. In alkaline soils there is manganese deficiency. The critical level of Mn is 675 μg:g -1 , above this value manganese is toxic to the plant, but the bio solids applied had a concentration of 300 μg:g -1 , below the critical level. 16 samples were analyzed, and various elements were detected. But the interest in this work was to evaluate the behavior of Mn with increasing the amount of bio solids used as manure. Three different concentrations of bio solids: 10 kg:ha -1 ; 20 kg:ha -1 and 40 kg:ha -1 were applied. Alkaline bio solids provides an increase of the soil pH, which cause the reduction of the manganese availability. The bio solid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown into sanitary lands. The level of pH above 5.5 causes the Mn reduction. The values obtained showed this reduction of Mn phytoavailability with the bio solids increase. (author)

  13. Study of bioavailability of Mn in soil manured with bio solids using neutron activation analysis (NAA)

    Energy Technology Data Exchange (ETDEWEB)

    Mateus, Natalina de Fatima [Secretaria da Educacao do Estado de Sao Paulo, SP (Brazil); Madi Filho, Tufic [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Full text: This work evaluated, using neutron activation analysis (NAA), the behavior of Mn absorption by Eucalyptus manured with bio solids. Manganese is an important micro nutrient because it is an activator of enzymes, controller of oxy reduction reactions, essential to the photosynthesis and synthesis of chlorophyll and protein. Its lack causes a decrease in photosynthesis, which reduces growth and productivity. In alkaline soils there is manganese deficiency. The critical level of Mn is 675 {mu}g:g{sup -1}, above this value manganese is toxic to the plant, but the bio solids applied had a concentration of 300 {mu}g:g{sup -1}, below the critical level. 16 samples were analyzed, and various elements were detected. But the interest in this work was to evaluate the behavior of Mn with increasing the amount of bio solids used as manure. Three different concentrations of bio solids: 10 kg:ha{sup -1}; 20 kg:ha{sup -1} and 40 kg:ha{sup -1} were applied. Alkaline bio solids provides an increase of the soil pH, which cause the reduction of the manganese availability. The bio solid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown into sanitary lands. The level of pH above 5.5 causes the Mn reduction. The values obtained showed this reduction of Mn phytoavailability with the bio solids increase. (author)

  14. Activity of the ligninolytic enzymes of the Phanerochaete chrysosporium and its variation with the Mn+2 addition

    International Nuclear Information System (INIS)

    Jimenez T, Gloria Alicia; Mejia G, Amanda I; Lopez O, Betty Lucy

    1999-01-01

    The activity of the ligninolytic enzymes, lignin peroxidase (LiP), manganese peroxidase (MnP) and Laccase, in submerged cultures of Phanerochaete chrysosporium, with limited amounts of carbon and nitrogen, were affected by the addition of Mn+2. In cultures with o and 1,25 ppm of Mn+2, only the lip was detected and its higher activity level was observed in the cultures with 1.25 ppm of Mn+2. The cultures with 40 ppm of Mn+2 showed activities of lip, MnP and Laccase. The presence of the three enzymes in the same culture had not been reported and it is of great importance because is shows that the fungus and its lignolitic machinery can act sequentially

  15. Agnostic Active Learning Without Constraints

    OpenAIRE

    Beygelzimer, Alina; Hsu, Daniel; Langford, John; Zhang, Tong

    2010-01-01

    We present and analyze an agnostic active learning algorithm that works without keeping a version space. This is unlike all previous approaches where a restricted set of candidate hypotheses is maintained throughout learning, and only hypotheses from this set are ever returned. By avoiding this version space approach, our algorithm sheds the computational burden and brittleness associated with maintaining version spaces, yet still allows for substantial improvements over supervised learning f...

  16. AuRu/meso-Mn2O3: A Highly Active and Stable Catalyst for Methane Combustion

    Science.gov (United States)

    Han, Z.; Fang, J. Y.; Xie, S. H.; Deng, J. G.; Liu, Y. X.; Dai, H. X.

    2018-05-01

    Three-dimensionally ordered mesoporous Mn2O3 (meso-Mn2O3) and its supported Au, Ru, and AuRu alloy (0.49 wt% Au/meso-Mn2O3, 0.48 wt% Ru/meso-Mn2O3, and 0.97 wt% AuRu/meso-Mn2O3 (Au/Ru molar ratio = 0.98)) nanocatalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected reduction methods, respectively. Physicochemical properties of the samples were characterized by means of numerous techniques, and their catalytic activities were evaluated for the combustion of methane. It is found that among all of the samples, 0.48 wt% Ru/meso-Mn 2O3 and 0.97 wt% AuRu/meso-Mn2O3 performed the best (the reaction temperature (T90% ) at 90% methane conversion was 530-540°C), but the latter showed a better thermal stability than the former. The partial deactivation of 0.97 wt% AuRu/meso-Mn2O3 due to H2O or CO2 introduction was reversible. It is concluded that the good catalytic activity and thermal stability of 0.97 wt% AuRu/meso-Mn2O3 was associated with the high dispersion of AuRu alloy NPs (2-5 nm) on the surface of meso-Mn2O3 and good low-temperature reducibility.

  17. Active Learning Using Arbitrary Binary Valued Queries

    Science.gov (United States)

    1990-10-01

    active learning in the sense that the learner has complete choice in the information received. Specifically, we allow the learner to ask arbitrary yes...no questions. We consider both active learning under a fixed distribution and distribution-free active learning . In the case of active learning , the...a concept class is actively learnable iff it is finite, so that active learning is in fact less powerful than the usual passive learning model. We

  18. Low-activation Mn-Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Saida, T.; Hirai, S. [Mitsubishi Heavy Ind. Ltd., Yokohama (Japan); Kusuhashi, M.; Sato, I.; Hatakeyama, T. [The Japan Steel Works Ltd., Chatsu-machi 4, Muroran 051-8505 (Japan)

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels. (orig.) 22 refs.

  19. Low-activation Mn Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Science.gov (United States)

    Onozuka, Masanori; Saida, Tomikane; Hirai, Shouzou; Kusuhashi, Mikio; Sato, Ikuo; Hatakeyama, Tsuyoshi

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels.

  20. Oxidative Ce"3"+ sequestration by fungal manganese oxides with an associated Mn(II) oxidase activity

    International Nuclear Information System (INIS)

    Zheng, Haisu; Tani, Yukinori; Naitou, Hirotaka; Miyata, Naoyuki; Tojo, Fuyumi

    2016-01-01

    Sequestration of Ce"3"+ by biogenic manganese oxides (BMOs) formed by a Mn(II)-oxidizing fungus, Acremonium strictum strain KR21-2, was examined at pH 6.0. In anaerobic Ce"3"+ solution, newly formed BMOs exhibited stoichiometric Ce"3"+ oxidation, where the molar ratio of Ce"3"+ sequestered (Ce_s_e_q) relative to Mn"2"+ released (Mn_r_e_l) was maintained at approximately two throughout the reaction. A similar Ce"3"+ sequestration trend was observed in anaerobic treatment of BMOs in which the associated Mn(II) oxidase was completely inactivated by heating at 85 °C for 1 h or by adding 50 mM NaN_3. Aerobic Ce"3"+ treatment of newly formed BMO (enzymatically active) resulted in excessive Ce"3"+ sequestration over Mn"2"+ release, yielding Ce_s_e_q/Mn_r_e_l > 200, whereas heated or poisoned BMOs released a significant amount of Mn"2"+ with lower Ce"3"+ sequestration efficiency. Consequently, self-regeneration by the Mn(II) oxidase in newly formed BMO effectively suppressed Mn"2"+ release and enhanced oxidative Ce"3"+ sequestration under aerobic conditions. Repeated treatments of heated or poisoned BMOs under aerobic conditions confirmed that oxidative Ce"3"+ sequestration continued even after most Mn oxide was released from the solid phase, indicating auto-catalytic Ce"3"+ oxidation at the solid phase produced through primary Ce"3"+ oxidation by BMO. From X-ray diffraction analysis, the resultant solid phases formed through Ce"3"+ oxidation by BMO under both aerobic and anaerobic conditions consisted of cerianite with crystal sizes of 5.00–7.23 Å. Such nano-sized CeO_2 (CeO_2_,_B_M_O) showed faster auto-catalytic Ce"3"+ oxidation than that on well-crystalized cerianite under aerobic conditions, where the normalized pseudo-first order rate constants for auto-catalytic Ce"3"+ oxidation on CeO_2_,_B_M_O was two orders of magnitude higher. Consequently, we concluded that Ce"3"+ contact with BMOs sequesters Ce"3"+ through two oxidation paths: primary Ce"3

  1. Active Learning Through Discussion in E-Learning

    OpenAIRE

    Daru Wahyuningsih

    2016-01-01

    Active learning is generally made by a lecturer in learning face to face. In the face to face learning, lecturer can implement a variety of teaching methods to make students actively involved in learning. This is different from learning that is actuating in e-learning. The main characteristic of e-learning is learning that can take place anytime and anywhere. Special strategies are needed so that lecturer can make students play an active role in the course of e-learning. Research in order to ...

  2. Constructing MnO{sub 2}/single crystalline ZnO nanorod hybrids with enhanced photocatalytic and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Weiwei [College of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China); Liu, Tiangui, E-mail: tianguiliu@gmail.com [College of Physics and Microelectronics Science, Hunan University, Changsha 410082 (China); Cao, Shiyi; Wang, Chen [College of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China); Chen, Chuansheng, E-mail: 1666423158@qq.com [College of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China)

    2016-07-15

    In order to improve the photocatalytic and antibacterial activity of ZnO nanorods, ZnO nanorods decorated with MnO{sub 2} nanoparticles (MnO{sub 2}/ZnO nanorod hybrids) were prepared by using microwave assisted coprecipitation method under the influence of hydrogen peroxide, and the structure, photocatalytic activity and antibacterial property of the products were studied. Experimental results indicated that MnO{sub 2} nanoparticles are decorated on the surface of single crystalline ZnO nanorods. Moreover, the resultant MnO{sub 2}/ZnO nanorod hybrids have been proven to possess good photocatalytic and antibacterial activity, which their degradated efficiency for Rhodamin B (RhB) is twice as the pure ZnO nanorods. Enhancement for photocatalytic and antibacterial activity is mainly attributed to the low band gap energy and excellent electrochemical properties of MnO{sub 2} nanoparticles. - Graphical abstract: The MnO{sub 2}/single crystalline ZnO nanorods hybrids, which MnO{sub 2} nanoparticles are loaded on the surface of ZnO nanorods, were prepared by the step-by-step precipitation method under the assistance of ammonia and hydrogen peroxide. Display Omitted - Highlights: • MnO{sub 2}/ZnO nanorod hybrids were prepared by the step-by-step assembly method. • Single crystalline ZnO nanorods can be decorated by MnO{sub 2} nanoparticles. • MnO{sub 2}/ZnO nanorod hybrids possess good photocatalytic and antibacterial activity. • MnO{sub 2} can improve the photocatalytic activity of ZnO nanorods under visible light.

  3. Toward an Active and Stable Catalyst for Oxygen Evolution in Acidic Media: Ti-Stabilized MnO2

    DEFF Research Database (Denmark)

    Frydendal, Rasmus; Paoli, Elisa Antares; Chorkendorff, Ib

    2015-01-01

    Catalysts are required for the oxygen evolution reaction, which are abundant, active, and stable in acid. MnO2 is a promising candidate material for this purpose. However, it dissolves at high overpotentials. Using first-principles calculations, a strategy to mitigate this problem by decorating...... undercoordinated surface sites of MnO2 with a stable oxide is developed here. TiO2 stands out as the most promising of the different oxides in the simulations. This prediction is experimentally verified by testing sputter-deposited thin films of MnO2 and Ti-MnO2. A combination of electrochemical measurements...

  4. The International Active Learning Space

    DEFF Research Database (Denmark)

    Manners, Ian James

    2015-01-01

    -Danish students receive the basic international and intercultural skills and knowledge they need in current society. The English-language masters’ seminars I teach at the Department of Political Science are international in terms of students and teacher, but they are also Active Learning seminars......-Danish students (and sometimes teachers) rarely speak to each other or learn each other’s names. In the international AL spaces I create, students must work together on joint tasks which require interaction to address tasks and integration in order to benefit from the multinational activity groups. Planning AL...... that complete the seminar soon become vocal advocates of international AL. Ultimately, enriching student learning through immersing Danish and international students in an international AL space is, for me, the best way of ensuring an internationalised learning outcome, rather than just international mobility....

  5. Active learning of Pareto fronts.

    Science.gov (United States)

    Campigotto, Paolo; Passerini, Andrea; Battiti, Roberto

    2014-03-01

    This paper introduces the active learning of Pareto fronts (ALP) algorithm, a novel approach to recover the Pareto front of a multiobjective optimization problem. ALP casts the identification of the Pareto front into a supervised machine learning task. This approach enables an analytical model of the Pareto front to be built. The computational effort in generating the supervised information is reduced by an active learning strategy. In particular, the model is learned from a set of informative training objective vectors. The training objective vectors are approximated Pareto-optimal vectors obtained by solving different scalarized problem instances. The experimental results show that ALP achieves an accurate Pareto front approximation with a lower computational effort than state-of-the-art estimation of distribution algorithms and widely known genetic techniques.

  6. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... that the method can be used online during the content generation process where the mod- els can improve and better content can be presented as the game is being played....

  7. Preparation and photoluminescence properties of Mn2+-activated M2Si5N8 (M = Ca, Sr, Ba) phosphors

    NARCIS (Netherlands)

    Duan, C.J.; Otten, W.M.; Delsing, A.C.A.; Hintzen, H.T.J.M.

    2008-01-01

    Mn2+-doped M2Si5N8 (M=Ca, Sr, Ba) phosphors have been prepared by a solid-state reaction method at high temperature and their photoluminescence properties were investigated. The Mn2+-activated M2Si5N8 phosphors exhibit narrow emission bands in the wavelength range of 500–700 nm with peak center at

  8. Active Learning versus Traditional Teaching

    Directory of Open Access Journals (Sweden)

    L.A. Azzalis

    2009-05-01

    Full Text Available In traditional teaching most of the class time is spent with the professor lecturing and the students watching and listening. The students work individually, and cooperation is discouraged. On the other hand,  active learning  changes the focus of activity from the teacher to the learners, in which students solve problems, answer questions, formulate questions of their own, discuss, explain, debate during class;  moreover, students work in teams on problems and projects under conditions that assure positive interdependence and individual accountability. Although student-centered methods have repeatedly been shown to be superior to the traditional teacher-centered approach to instruction, the literature regarding the efficacy of various teaching methods is inconclusive. The purpose of this study was to compare the student perceptions of course and instructor effectiveness, course difficulty, and amount learned between the active learning and lecture sections  in Health Sciences´ courses by statistical data from Anhembi Morumbi University. Results indicated significant  difference between active  learning and traditional  teaching. Our conclusions were that strategies promoting  active  learning to  traditional lectures could increase knowledge and understanding.

  9. Electrochemical activation of Li2MnO3 at elevated temperature investigated by in situ Raman microscopy

    International Nuclear Information System (INIS)

    Lanz, Patrick; Villevieille, Claire; Novák, Petr

    2013-01-01

    Layered-layered oxides of the type xLi 2 MnO 3 ·(1 − x)LiMO 2 (M = Mn, Ni, Co) have been postulated to contain Li 2 MnO 3 domains which, upon electrochemical activation, give rise to a characteristic potential plateau at 4.5 V vs. Li + /Li. To improve our understanding of the complex reaction mechanisms at play, we applied in situ Raman microscopy to investigate the constituent Li 2 MnO 3 . Li 2 MnO 3 synthesised via a two-step solid-state reaction was characterised by scanning electron microscopy and X-ray diffraction. Preliminary electrochemical tests and ex situ Raman microscopy showed the need for elevated temperatures to achieve activation. For the first time, in situ Raman microscopy (at 50 °C) confirmed the activation of Li 2 MnO 3 . The main signal at 615 cm −1 shifted to higher wavenumbers upon charging. After reaching 4.4 V vs. Li + /Li, this shift grew significantly, which is in good agreement with the onset of the potential plateau in both Li 2 MnO 3 and xLi 2 MnO 3 ·(1 − x)LiMO 2 , and is assigned to the partial formation of a spinel-like phase

  10. Dietary resveratrol administration increases MnSOD expression and activity in mouse brain

    International Nuclear Information System (INIS)

    Robb, Ellen L.; Winkelmolen, Lieke; Visanji, Naomi; Brotchie, Jonathan; Stuart, Jeffrey A.

    2008-01-01

    trans-Resveratrol (3,4',5-trihydroxystilbene; RES) is of interest for its reported protective effects in a variety of pathologies, including neurodegeneration. Many of these protective properties have been attributed to the ability of RES to reduce oxidative stress. In vitro studies have shown an increase in antioxidant enzyme activities following exposure to RES, including upregulation of mitochondrial superoxide dismutase, an enzyme that is capable of reducing both oxidative stress and cell death. We sought to determine if a similar increase in endogenous antioxidant enzymes is observed with RES treatment in vivo. Three separate modes of RES delivery were utilized; in a standard diet, a high fat diet and through a subcutaneous osmotic minipump. RES given in a high fat diet proved to be effective in elevating antioxidant capacity in brain resulting in an increase in both MnSOD protein level (140%) and activity (75%). The increase in MnSOD was not due to a substantial proliferation of mitochondria, as RES treatment induced a 10% increase in mitochondrial abundance (Citrate Synthase activity). The potential neuroprotective properties of MnSOD have been well established, and we demonstrate that a dietary delivery of RES is able to increase the expression and activity of this enzyme in vivo

  11. Active learning for Corsika

    Energy Technology Data Exchange (ETDEWEB)

    Baack, Dominik; Temme, Fabian; Buss, Jens; Noethe, Max; Bruegge, Kai [TU Dortmund, Dortmund (Germany); Collaboration: FACT-Collaboration

    2016-07-01

    Modern Cosmic-Ray experiments need a huge amount of simulated data. In many cases, only a portion of the data is actually needed for following steps in the analysis chain, for example training of different machine learning algorithms. The other parts are thrown away by the trigger simulation of the experiment or so not increase the quality of following analysis steps. In this talk, I present a new developed package for the air shower simulation software CORSIKA. This extension includes different approaches to reduce the amount of unnecessary computation. One approach is a new internal particle stack implementation that allows to priorize the processing of special intermediate shower particles and the removal of not needed shower particles. The second approach is the possibility to sent various information of the initial particle and parameters of the status of the partial simulated event to an external application to approximate the information gain of the current simulator event. If the information gain is to low, the current event simulation gets terminated and all information get stored into a central database. For the Simulation - Server communication a simple network protocol has been developed.

  12. Enhancing Photocatalytic Activity on (MnO@TNTAs):Mn2+ with a Hierarchical Sandwich-Like Nanostructure via a Two-Step Procedure

    Science.gov (United States)

    Kong, Junhan; Zhang, Wei; Zhang, Yubo; Xia, Minghao; Wu, Xiuling; Wang, Yongqian

    2018-02-01

    Several semiconductor nanomaterial devices are increasingly being applied in a variety of fields, especially in the treating of environmental pollutants. We have fabricated (MnO@TNTAs):Mn2+ with sandwich-like nanostructures composed of TiO2 nanotube arrays (TNTAs), Mn-doped TNTAs and MnO. The experimental procedure was a two-step synthesis: first, using anodic oxidation methods and then hydrothermal methods. We carried out many characterizations of the "sandwiches" in the nanoscale. From the field emission scanning electron microscopy images we found nanofibers lying on the highly-ordered nanotube arrays. The diameter of the nanotubes was about 50 nm but the size of the nanofibers varied. Energy dispersive spectroscopy demonstrated that the nanofibers contained a manganese element and x-ray diffraction patterns showed the peak of the manganosite phase. From ultraviolet-visible light spectra, it was found that the nanostructures had strong absorption activities under both ultraviolet and visible light radiation, while pure TNTAs had absorption only under ultraviolet light. The photodegradation experiments proved that the sandwich-like nanostructures had an excellent photocatalytic activity (92.5% after 240 min), which was a great improvement compared with pure TNTAs. In this way, the structures as a device at the nanoscale have a huge potential in controlling environmental pollution.

  13. Significant in vivo anti-inflammatory activity of Pytren4Q-Mn a superoxide dismutase 2 (SOD2 mimetic scorpiand-like Mn (II complex.

    Directory of Open Access Journals (Sweden)

    Carolina Serena

    Full Text Available The clinical use of purified SOD enzymes has strong limitations due to their large molecular size, high production cost and immunogenicity. These limitations could be compensated by using instead synthetic SOD mimetic compounds of low molecular weight.We have recently reported that two SOD mimetic compounds, the Mn(II complexes of the polyamines Pytren2Q and Pytren4Q, displayed high antioxidant activity in bacteria and yeast. Since frequently molecules with antioxidant properties or free-radical scavengers also have anti-inflammatory properties we have assessed the anti-inflammatory potential of Pytren2Q and Pytren4Q Mn(II complexes, in cultured macrophages and in a murine model of inflammation, by measuring the degree of protection they could provide against the cellular injury produced by lipopolisacharide, a bacterial endotoxin.In this report we show that the Mn(II complex of Pytren4Q but not that of Pytren2Q effectively protected human cultured THP-1 macrophages and whole mice from the inflammatory effects produced by LPS. These results obtained with two molecules that are isomers highlight the importance of gathering experimental data from animal models of disease in assessing the potential of candidate molecules.The effective anti-inflammatory activity of the Mn(II complex of Pytren4Q in addition to its low toxicity, water solubility and ease of production would suggest it is worth taking into consideration for future pharmacological studies.

  14. Synthesis, characterization and photocatalytic activity of LaMnO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shaterian, Maryam, E-mail: shaterian@znu.ac.ir [Department of Chemistry, Faculty of Science, University of Zanjan, Zanjan 45371-38791, Islamic Republic of Iran (Iran, Islamic Republic of); Enhessari, Morteza [Department of Chemistry, Islamic Azad University, Naragh Branch, Naragh, Islamic Republic of Iran (Iran, Islamic Republic of); Rabbani, Davarkhah [Department of Environmental Health Engineering, School of Health, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Asghari, Morteza [Separation Processes Research Group (SPRG), Department of Engineering, University of Kashan, Kashan, PO Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Salavati-Niasari, Masoud [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, PO Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of)

    2014-11-01

    Highlights: • Visible-light sensitive LaMnO3 nanoparticles were synthesized via sol–gel process. • Structural and optical properties of photocatalysts have been investigated. • The photocatalytic activity was evaluated by the degradation of methyl orange as a model of pollutant. • The prepared nanocrystals showed good visible-light photocatalytic activity for the degradation of methyl orange. - Abstract: Visible-light sensitive LaMnO{sub 3} nanoparticles were synthesized via sol–gel process using stearic acid as complexing reagent. Characterizations of the resulting powders were carried out by means of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS). Further, the photocatalytic activity of LaMnO{sub 3} was evaluated by degradation of methyl orange in aqueous solution under visible-light irradiation. The prepared nanoparticles showed excellent visible-light photocatalytic ability for the degradation of methyl orange so that, 60 ppm of nanoparticles can decolorizes the methyl orange solution (6 ppm) up to 98% in 90 min.

  15. Synthesis, characterization and photocatalytic activity of LaMnO3 nanoparticles

    International Nuclear Information System (INIS)

    Shaterian, Maryam; Enhessari, Morteza; Rabbani, Davarkhah; Asghari, Morteza; Salavati-Niasari, Masoud

    2014-01-01

    Highlights: • Visible-light sensitive LaMnO3 nanoparticles were synthesized via sol–gel process. • Structural and optical properties of photocatalysts have been investigated. • The photocatalytic activity was evaluated by the degradation of methyl orange as a model of pollutant. • The prepared nanocrystals showed good visible-light photocatalytic activity for the degradation of methyl orange. - Abstract: Visible-light sensitive LaMnO 3 nanoparticles were synthesized via sol–gel process using stearic acid as complexing reagent. Characterizations of the resulting powders were carried out by means of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS). Further, the photocatalytic activity of LaMnO 3 was evaluated by degradation of methyl orange in aqueous solution under visible-light irradiation. The prepared nanoparticles showed excellent visible-light photocatalytic ability for the degradation of methyl orange so that, 60 ppm of nanoparticles can decolorizes the methyl orange solution (6 ppm) up to 98% in 90 min

  16. Lectures Abandoned: Active Learning by Active Seminars

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Corry, Aino Vonge

    2012-01-01

    Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

  17. Active Learning in Introductory Climatology.

    Science.gov (United States)

    Dewey, Kenneth F.; Meyer, Steven J.

    2000-01-01

    Introduces a software package available for the climatology curriculum that determines possible climatic events according to a long-term climate history. Describes the integration of the software into the curriculum and presents examples of active learning. (Contains 19 references.) (YDS)

  18. Oral Hygiene. Learning Activity Package.

    Science.gov (United States)

    Hime, Kirsten

    This learning activity package on oral hygiene is one of a series of 12 titles developed for use in health occupations education programs. Materials in the package include objectives, a list of materials needed, a list of definitions, information sheets, reviews (self evaluations) of portions of the content, and answers to reviews. These topics…

  19. Minimax bounds for active learning

    NARCIS (Netherlands)

    Castro, R.M.; Nowak, R.; Bshouty, N.H.; Gentile, C.

    2007-01-01

    This paper aims to shed light on achievable limits in active learning. Using minimax analysis techniques, we study the achievable rates of classification error convergence for broad classes of distributions characterized by decision boundary regularity and noise conditions. The results clearly

  20. Fe-Mn bi-metallic oxides loaded on granular activated carbon to enhance dye removal by catalytic ozonation.

    Science.gov (United States)

    Tang, Shoufeng; Yuan, Deling; Zhang, Qi; Liu, Yameng; Zhang, Qi; Liu, Zhengquan; Huang, Haiming

    2016-09-01

    A Fe-Mn bi-metallic oxide supported on granular activated carbon (Fe-Mn GAC) has been fabricated by an impregnation-desiccation method and tested in the catalytic ozonation of methyl orange (MO) degradation and mineralization. X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy characterizations revealed that Fe-Mn oxides were successfully loaded and uniformly distributed on the GAC, and nitrogen adsorption isotherms showed that the supported GAC retained a large surface area and a high pore volume compared with the pristine GAC. The catalytic activity was systematically assessed by monitoring the MO removal efficiencies at different operational parameters, such as catalyst dosage, initial solution pH, and ozone flow rate. The Fe-Mn GAC exhibited better catalytic activity relative to ozone alone and GAC alone, improving the TOC removal by 24.5 and 11.5 % and COD removal by 13.6 and 7.3 %, respectively. The reusability of the hybrid was examined over five consecutive cyclic treatments. The Fe-Mn GAC catalytic activity was only a slight loss in the cycles, showing good stability. The addition of Na2CO3 as hydroxyl radicals (•OH) scavengers proved that the catalytic ozonation mechanism was the enhanced generation of •OH by the Fe-Mn GAC. The above results render the Fe-Mn GAC an industrially promising candidate for catalytic ozonation of dye contaminant removal.

  1. Effect of calcination temperature on structural properties and photocatalytic activity of Mn-C-codoped TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Jianbo; Xin, Wei; Liu, Guanglong; Lin, Die; Zhu, Duanwei, E-mail: liugl@mail.hzau.edu.cn [Laboratory of Eco-Environmental Engineering Research, College of Resources and Environment, Huazhong Agricultural University (HZAU), Wuhan (China)

    2016-03-15

    Mn-C-codoped TiO{sub 2} catalysts were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylene sorbitan monooleate (Tween 80) as template and carbon precursor and the effect of calcination temperature on their structural properties and photocatalytic activity were investigated. The XRD results showed undoped and Mn-C-codoped TiO{sub 2} calcined at 400 deg C only include anatase phase and the rutile phase appears when the calcination temperature reached to 600 deg C. UV-vis absorption spectroscopy demonstrates that the absorption spectra are strongly modified by the calcination temperature. Moreover, the Mn-C-TiO{sub 2} calcined at 400 deg C showed the lowest PL intensity due to a decrease in the recombination rate of photogenerated electrons and holes under light irradiation. The photocatalytic activity of Mn-C-codoped TiO{sub 2} were evaluated by the degradation of methyl orange (MO) under the simulate daylight irradiation and all the prepared Mn-C-codoped TiO{sub 2} samples exhibited high photocatalytic activities for photocatalytic decolorisation of methyl orange aqueous solution. At 400 deg C, the Mn-C-codoped TiO{sub 2} samples showed the highest photocatalytic activity due to synergetic effects of good crystallize ation, appropriate phase composition and slower recombination rate of photogenerated charge carriers, which further confirms the calcination temperature could affect the properties of Mn-C-codoped TiO2 significantly. (author)

  2. Engaging Students' Learning Through Active Learning

    Directory of Open Access Journals (Sweden)

    Margaret Fitzsimons

    2014-06-01

    Full Text Available This paper discusses a project carried out with thirty six final year undergraduate students, studying the Bachelor of Science in Business and Management and taking the module Small Business Management during the academic year 2012 and 2013 in Dublin Institute of Technology. The research had two separate objectives, 1 to engage in active learning by having students work on a consulting project in groups for a real life business and 2 to improve student learning. The Small Business Management previously had a group assignment that was to choose an article related to entrepreneurship and critic it and present it to the class. Anecdotally, from student feedback, it was felt that this process did not engage students and also did not contribute to the key competencies necessary in order to be an entrepreneur. The desire was for students on successful completion of this module to have better understood how business is conducted and equip them with core skills such as innovation, critical thinking, problem solving and decision making .Student buy in was achieved by getting the students to select their own groups and also work out between each group from a one page brief provided by the businesses which business they would like to work with. It was important for the businesses to also feel their time spent with students was worthwhile so they were presented with a report from the students at the end of the twelve weeks and invited into the College to hear the presentations from students. Students were asked to provide a reflection on their three key learning points from the assignment and to answer specific questions designed to understand what they learnt and how and their strengths and weaknesses. A survey was sent to the businesses that took part to understand their experiences. The results were positive with student engagement and learning rating very highly and feedback from the businesses demonstrated an appreciation of having a different

  3. Defect induced activation of Raman silent modes in rf co-sputtered Mn doped ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Harish Kumar [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India); Sreenivas, K [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India); Katiyar, R S [Department of Physics, University of Puerto Rico, San Juan, PR 00931-3343 (Puerto Rico); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India)

    2007-10-07

    We study the influence of Mn doping on the vibrational properties of rf sputtered ZnO thin films. Raman spectra of the Mn doped ZnO samples reveal two additional vibrational modes, in addition to the host phonon modes, at 252 and 524 cm{sup -1}. The intensity of the additional modes increases continuously with Mn concentration in ZnO and can be used as an indication of Mn incorporation in ZnO. The modes are assigned to the activation of ZnO silent modes due to relaxation of Raman selection rules produced by the breakdown of the translational symmetry of the crystal lattice with the incorporation of Mn at the Zn site. Furthermore, the A{sub 1} (LO) mode is observed with very high intensity in the Raman spectra of undoped ZnO thin film and is attributed to the built-in electric field at the grain boundaries.

  4. Defect induced activation of Raman silent modes in rf co-sputtered Mn doped ZnO thin films

    International Nuclear Information System (INIS)

    Yadav, Harish Kumar; Sreenivas, K; Katiyar, R S; Gupta, Vinay

    2007-01-01

    We study the influence of Mn doping on the vibrational properties of rf sputtered ZnO thin films. Raman spectra of the Mn doped ZnO samples reveal two additional vibrational modes, in addition to the host phonon modes, at 252 and 524 cm -1 . The intensity of the additional modes increases continuously with Mn concentration in ZnO and can be used as an indication of Mn incorporation in ZnO. The modes are assigned to the activation of ZnO silent modes due to relaxation of Raman selection rules produced by the breakdown of the translational symmetry of the crystal lattice with the incorporation of Mn at the Zn site. Furthermore, the A 1 (LO) mode is observed with very high intensity in the Raman spectra of undoped ZnO thin film and is attributed to the built-in electric field at the grain boundaries

  5. Internal exposure to neutron-activated {sup 56}Mn dioxide powder in Wistar rats. Pt. 2. Pathological effects

    Energy Technology Data Exchange (ETDEWEB)

    Shichijo, Kazuko; Mussazhanova, Zhanna; Niino, Daisuke; Nakashima, Masahiro; Tomonaga, Masao [Nagasaki University, Nagasaki (Japan); Fujimoto, Nariaki; Hoshi, Masaharu [Hiroshima University, Hiroshima (Japan); Uzbekov, Darkhan; Kairkhanova, Ynkar; Saimova, Aisulu; Chaizhunusova, Nailya; Sayakenov, Nurlan; Shabdarbaeva, Dariya; Aukenov, Nurlan; Rakhypbekov, Tolebay [Semey State Medical University, Semey (Kazakhstan); Azimkhanov, Almas; Kolbayenkov, Alexander [National Nuclear Center of the Republic of Kazakhstan, Kurchatov (Kazakhstan); Zhumadilov, Kassym [L.N. Gumilyov Eurasian National University, Astana (Kazakhstan); Stepanenko, Valeriy [A. Tsyb Medical Radiological Research Center, National Medical Research Radiological Center, Ministry of Health of Russian Federation, Obninsk, Kaluga region (Russian Federation)

    2017-03-15

    To fully understand the radiation effects of the atomic bombing of Hiroshima and Nagasaki among the survivors, radiation from neutron-induced radioisotopes in soil and other materials should be considered in addition to the initial radiation directly received from the bombs. This might be important for evaluating the radiation risks to the people who moved to these cities soon after the detonations and probably inhaled activated radioactive ''dust.'' Manganese-56 is known to be one of the dominant radioisotopes produced in soil by neutrons. Due to its short physical half-life, {sup 56}Mn emits residual radiation during the first hours after explosion. Hence, the biological effects of internal exposure of Wistar rats to {sup 56}Mn were investigated in the present study. MnO{sub 2} powder was activated by a neutron beam to produce radioactive {sup 56}Mn. Rats were divided into four groups: those exposed to {sup 56}Mn, to non-radioactive Mn, to {sup 60}Co γ rays (2 Gy, whole body), and those not exposed to any additional radiation (control). On days 3, 14, and 60 after exposure, the animals were killed and major organs were dissected and subjected to histopathological analysis. As described in more detail by an accompanying publication, the highest internal radiation dose was observed in the digestive system of the rats, followed by the lungs. It was found that the number of mitotic cells increased in the small intestine on day 3 after {sup 56}Mn and {sup 60}Co exposure, and this change persisted only in {sup 56}Mn-exposed animals. Lung tissue was severely damaged only by exposure to {sup 56}Mn, despite a rather low radiation dose (less than 0.1 Gy). These data suggest that internal exposure to {sup 56}Mn has a significant biological impact on the lungs and small intestine. (orig.)

  6. Structural explanation for the role of Mn2+ in the activity of phi6 RNA-dependent RNA polymerase.

    Science.gov (United States)

    Poranen, Minna M; Salgado, Paula S; Koivunen, Minni R L; Wright, Sam; Bamford, Dennis H; Stuart, David I; Grimes, Jonathan M

    2008-11-01

    The biological role of manganese (Mn(2+)) has been a long-standing puzzle, since at low concentrations it activates several polymerases whilst at higher concentrations it inhibits. Viral RNA polymerases possess a common architecture, reminiscent of a closed right hand. The RNA-dependent RNA polymerase (RdRp) of bacteriophage 6 is one of the best understood examples of this important class of polymerases. We have probed the role of Mn(2+) by biochemical, biophysical and structural analyses of the wild-type enzyme and of a mutant form with an altered Mn(2+)-binding site (E491 to Q). The E491Q mutant has much reduced affinity for Mn(2+), reduced RNA binding and a compromised elongation rate. Loss of Mn(2+) binding structurally stabilizes the enzyme. These data and a re-examination of the structures of other viral RNA polymerases clarify the role of manganese in the activation of polymerization: Mn(2+) coordination of a catalytic aspartate is necessary to allow the active site to properly engage with the triphosphates of the incoming NTPs. The structural flexibility caused by Mn(2+) is also important for the enzyme dynamics, explaining the requirement for manganese throughout RNA polymerization.

  7. Active Learning with Irrelevant Examples

    Science.gov (United States)

    Wagstaff, Kiri; Mazzoni, Dominic

    2009-01-01

    An improved active learning method has been devised for training data classifiers. One example of a data classifier is the algorithm used by the United States Postal Service since the 1960s to recognize scans of handwritten digits for processing zip codes. Active learning algorithms enable rapid training with minimal investment of time on the part of human experts to provide training examples consisting of correctly classified (labeled) input data. They function by identifying which examples would be most profitable for a human expert to label. The goal is to maximize classifier accuracy while minimizing the number of examples the expert must label. Although there are several well-established methods for active learning, they may not operate well when irrelevant examples are present in the data set. That is, they may select an item for labeling that the expert simply cannot assign to any of the valid classes. In the context of classifying handwritten digits, the irrelevant items may include stray marks, smudges, and mis-scans. Querying the expert about these items results in wasted time or erroneous labels, if the expert is forced to assign the item to one of the valid classes. In contrast, the new algorithm provides a specific mechanism for avoiding querying the irrelevant items. This algorithm has two components: an active learner (which could be a conventional active learning algorithm) and a relevance classifier. The combination of these components yields a method, denoted Relevance Bias, that enables the active learner to avoid querying irrelevant data so as to increase its learning rate and efficiency when irrelevant items are present. The algorithm collects irrelevant data in a set of rejected examples, then trains the relevance classifier to distinguish between labeled (relevant) training examples and the rejected ones. The active learner combines its ranking of the items with the probability that they are relevant to yield a final decision about which item

  8. Stimulating Deep Learning Using Active Learning Techniques

    Science.gov (United States)

    Yew, Tee Meng; Dawood, Fauziah K. P.; a/p S. Narayansany, Kannaki; a/p Palaniappa Manickam, M. Kamala; Jen, Leong Siok; Hoay, Kuan Chin

    2016-01-01

    When students and teachers behave in ways that reinforce learning as a spectator sport, the result can often be a classroom and overall learning environment that is mostly limited to transmission of information and rote learning rather than deep approaches towards meaningful construction and application of knowledge. A group of college instructors…

  9. Using IMS Learning Design to model collaborative learning activities

    NARCIS (Netherlands)

    Tattersall, Colin

    2006-01-01

    IMS Learning Design provides a counter to the trend towards designing for lone-learners reading from screens. It guides staff and educational developers to start not with content, but with learning activities and the achievement of learning objectives. It recognises that learning can happen without

  10. α-MnO2 Nanowires/Graphene Composites with High Electrocatalytic Activity for Mg-Air Fuel Cell

    International Nuclear Information System (INIS)

    Jiang, Min; He, Hao; Huang, Chen; Liu, Bo; Yi, Wen-Jun; Chao, Zi-Sheng

    2016-01-01

    Highlights: • α-MnO 2 NWs/graphene was synthesized and studied in Mg-air fuel cell. • The performance of α-MnO 2 NWs/graphene is close to the Pt/C. • The ORR mechanism involves a one-step, quasi-4-electron pathway. • A large area (5 cm*5 cm) cathode was prepared and tested in a full cell. - Abstract: This paper reports the preparation of α-MnO 2 NWs/graphene composites as the cathode catalyst for magnesium-air fuel cell and its excellent electrochemistry performance. The composites are synthesized by self-assembly of α-MnO 2 nan α-MnO 2 NWs/graphene was synthesized and studied in Mg-air fuel cell. α-MnO 2 NWs/graphene was synthesized and studied in Mg-air fuel cell. owires (NWs) on the surface of graphene via a simple hydrothermal method. The α-MnO 2 NWs/graphene composites showed a higher electrochemical activity than the commercial MnO 2 . The oxygen reduction peak of the α-MnO 2 NWs/graphene composites catalyst is tested in a 0.1 M KOH solution at −0.252 V, which is more positive than the commercial MnO 2 (−0.287 V). The ORR limit current density for 28% α-MnO2 NWs/graphene composite is approximately 2.74 mA/cm 2 , which is similar to that of the 20% Pt/C(2.79 mA/cm 2 ) in the same conditions. Based on the Koutecky–Levich plot, the ORR mechanism of the composite involves a one-step, quasi-4-electron pathway. In addition, magnesium-air fuel cell with α-MnO 2 NWs/graphene as catalyst possesses higher current density (140 mA/cm 2 ) and power density (96 mW/cm 2 ) compared to the commercial MnO 2 . This study proves that the cost-effective α-MnO 2 NWs/graphene with higher power generation ability make it possible for the substitute of the noble metals catalyst in the Mg-air fuel cell.

  11. Instructional Utility and Learning Efficacy of Common Active Learning Strategies

    Science.gov (United States)

    McConell, David A.; Chapman, LeeAnna; Czaijka, C. Douglas; Jones, Jason P.; Ryker, Katherine D.; Wiggen, Jennifer

    2017-01-01

    The adoption of active learning instructional practices in college science, technology, engineering, and mathematics (STEM) courses has been shown to result in improvements in student learning, contribute to increased retention rates, and reduce the achievement gap among different student populations. Descriptions of active learning strategies…

  12. IMPROVING CAUSE DETECTION SYSTEMS WITH ACTIVE LEARNING

    Data.gov (United States)

    National Aeronautics and Space Administration — IMPROVING CAUSE DETECTION SYSTEMS WITH ACTIVE LEARNING ISAAC PERSING AND VINCENT NG Abstract. Active learning has been successfully applied to many natural language...

  13. History and Evolution of Active Learning Spaces

    Science.gov (United States)

    Beichner, Robert J.

    2014-01-01

    This chapter examines active learning spaces as they have developed over the years. Consistently well-designed classrooms can facilitate active learning even though the details of implementing pedagogies may differ.

  14. Active Learning for Text Classification

    OpenAIRE

    Hu, Rong

    2011-01-01

    Text classification approaches are used extensively to solve real-world challenges. The success or failure of text classification systems hangs on the datasets used to train them, without a good dataset it is impossible to build a quality system. This thesis examines the applicability of active learning in text classification for the rapid and economical creation of labelled training data. Four main contributions are made in this thesis. First, we present two novel selection strategies to cho...

  15. Synthesis, Characterization, and Relative Study on the Catalytic Activity of Zinc Oxide Nanoparticles Doped MnCO3, –MnO2, and –Mn2O3 Nanocomposites for Aerial Oxidation of Alcohols

    Directory of Open Access Journals (Sweden)

    Mohamed E. Assal

    2017-01-01

    Full Text Available Zinc oxide nanoparticles doped manganese carbonate catalysts [X% ZnOx–MnCO3] (where X = 0–7 were prepared via a facile and straightforward coprecipitation procedure, which upon different calcination treatments yields different manganese oxides, that is, [X% ZnOx–MnO2] and [X% ZnOx–Mn2O3]. A comparative catalytic study was conducted to evaluate the catalytic efficiency between carbonates and oxides for the selective oxidation of secondary alcohols to corresponding ketones using molecular oxygen as a green oxidizing agent without using any additives or bases. The prepared catalysts were characterized by different techniques such as SEM, EDX, XRD, TEM, TGA, BET, and FTIR spectroscopy. The 1% ZnOx–MnCO3 calcined at 300°C exhibited the best catalytic performance and possessed highest surface area, suggesting that the calcination temperature and surface area play a significant role in the alcohol oxidation. The 1% ZnOx–MnCO3 catalyst exhibited superior catalytic performance and selectivity in the aerial oxidation of 1-phenylethanol, where 100% alcohol conversion and more than 99% product selectivity were obtained in only 5 min with superior specific activity (48 mmol·g−1·h−1 and 390.6 turnover frequency (TOF. The specific activity obtained is the highest so far (to the best of our knowledge compared to the catalysts already reported in the literatures used for the oxidation of 1-phenylethanol. It was found that ZnOx nanoparticles play an essential role in enhancing the catalytic efficiency for the selective oxidation of alcohols. The scope of the oxidation process is extended to different types of alcohols. A variety of primary, benzylic, aliphatic, allylic, and heteroaromatic alcohols were selectively oxidized into their corresponding carbonyls with 100% convertibility without overoxidation to the carboxylic acids under base-free conditions.

  16. Create a good learning environment and motivate active learning enthusiasm

    Science.gov (United States)

    Bi, Weihong; Fu, Guangwei; Fu, Xinghu; Zhang, Baojun; Liu, Qiang; Jin, Wa

    2017-08-01

    In view of the current poor learning initiative of undergraduates, the idea of creating a good learning environment and motivating active learning enthusiasm is proposed. In practice, the professional tutor is allocated and professional introduction course is opened for college freshman. It can promote communication between the professional teachers and students as early as possible, and guide students to know and devote the professional knowledge by the preconceived form. Practice results show that these solutions can improve the students interest in learning initiative, so that the active learning and self-learning has become a habit in the classroom.

  17. Intrinsic Activity of MnOx-CeO2 Catalysts in Ethanol Oxidation

    Directory of Open Access Journals (Sweden)

    Dimitrios Delimaris

    2017-11-01

    Full Text Available MnOx-CeO2 mixed oxides are considered efficient oxidation catalysts superior to the corresponding single oxides. Although these oxides have been the subject of numerous studies, their fundamental performance indicators, such as turnover frequency (TOF or specific activity, are scarcely reported. The purpose of the present work is to investigate the effect of catalyst composition on the concentration of active sites and intrinsic activity in ethanol oxidation by the employment of temperature-programmed desorption and oxidation of isotopically-labelled ethanol, 12CH313CH2OH. The transformation pathways of preadsorbed ethanol in the absence of gaseous oxygen refer to dehydrogenation to acetaldehyde followed by its dissociation combined with oxidation by lattice oxygen. In the presence of gaseous oxygen, lattice oxygen is rapidly restored and the main products are acetaldehyde, CO2, and water. CO2 forms less easily on mixed oxides than on pure MnOx. The TOF of ethanol oxidation has been calculated assuming that the amount of adsorbed ethanol and CO2 produced during temperature-programmed oxidation (TPO is a reliable indicator of the concentration of the active sites.

  18. Surface activation of MnNb{sub 2}O{sub 6} nanosheets by oxalic acid for enhanced photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junshu; Wang, Jinshu, E-mail: wangjsh@bjut.edu.cn; Li, Hongyi; Li, Yongli; Du, Yucheng; Yang, Yilong; Jia, Xinjian

    2017-05-01

    Graphical abstract: Visible light driven photoreduction of Cr(VI) over MnNb{sub 2}O{sub 6} nanosheets is enhanced via oxalic acid surface complex to generate activation layer. - Highlights: • MnNb{sub 2}O{sub 6} nanosheets are crystallized by a surface capping route of sulfonate groups. • Oxalic acid on MnNb{sub 2}O{sub 6} nanosheets forms an excited surface complex hybrid layer. • Surface activation enhances visible-light induced reduction of Cr(VI) into Cr(III). - Abstract: MnNb{sub 2}O{sub 6} nanosheets (P-MNOs) is selectively crystallized by using surface capping ligand with functional sulfonate group (sodium dodecyl benzene sulphonate), which binds to the (131) surface of MnNb{sub 2}O{sub 6} inducing the morphology-controlled crystallization of MnNb{sub 2}O{sub 6} materials. Surface modification of photoactive P-MNOs with electron-rich oxalic acid ligands establishes an excited surface complex layer on phase-pure P-MNO as evidenced by spectroscopic analyses (FT-IR, UV–vis, Raman, PL, etc.), and thus more efficiently photocatalyzes the reduction of Cr(VI) into Cr(III) than solely P-MNOs or oxalic acid under visible light (λ > 420 nm) via a ligand-to-metal interfacial electron transfer pathway. However, the interaction between oxalic acid and MnNb{sub 2}O{sub 6} is highly dependent upon the morphology of solid MnNb{sub 2}O{sub 6} substrate due to the higher surface-area-to-volume ratio and higher surface activity of (131) planes in the sheet-like morphology. This study could assist the construction of stable niobate material systems to allow a versatile solid surface activation for establishing more energy efficient and robust catalysis process under visible light.

  19. Determination of Na, Cl, Ca, Mg, Mn and K in milk samples by activation analysis

    International Nuclear Information System (INIS)

    Kira, Carmen S.; Maihara, Vera A.

    2000-01-01

    In the present work cow milk samples distributed for Sao Paulo government institutions, by means of the 'Viva leite' programme, have been monitored. The concentrations of Ca, Cl, K, Mg, Mn and Na were determined in five milk samples and in three different kinds of commercial powder milk, by instrumental neutron activation. For quality control, the reference materials NIST whole milk powder and non fat milk powder were analysed. The results obtained are in the range of the concentrations mentioned in the literature for these elements. (author)

  20. Study of crystal-field excitations and Raman active phonons in o-DyMnO3

    International Nuclear Information System (INIS)

    Jandl, S.; Mansouri, S.; Mukhin, A.A.; Yu Ivanov, V.; Balbashov, A.; Gospodino, M.M.; Nekvasil, V.; Orlita, M.

    2011-01-01

    In DyMnO 3 orthorhombic single crystals, the weak Raman active phonon softening below T=100 K is correlated with the study of infrared active Dy 3+ CF excitations as a function of temperature and under applied magnetic field. We detect five H 13/2 CF transitions that we predict with appropriate CF Hamiltonian and we confirm that the magnetic easy axis lies in the ab plane. While the CF energy level shifts below T=100 K reflect different displacements of the oxygen ions that contribute to the phonon softening, lifting of the ground state Kramers doublet degeneracy (∼30 cm -1 ) is observed below T N =39 K due to the anisotropic Mn 3+ -Dy 3+ interaction, which could be responsible for the stability of the bc-cycloid ferroelectric phase. - Research highlights: → Origin of Raman active phonon softening in the multiferroic o-DyMnO 3 . → A crystal-field study under magnetic field of Dy 3+ in o-DyMnO 3 . → Location of the magnetic easy axis in o-DyMnO 3 . → Lifting of Kramers doublet degeneracy in o-DyMnO 3 .

  1. Electrocatalytic activity and stability of Ag-MnOx/C composites toward oxygen reduction reaction in alkaline solution

    International Nuclear Information System (INIS)

    Wu, Qiumei; Jiang, Luhua; Qi, Luting; Yuan, Lizhi; Wang, Erdong; Sun, Gongquan

    2014-01-01

    Ag-MnO x /C composites were prepared using AgNO 3 and KMnO 4 as the precursors and Vulcan XC-72 as the support. The physical properties of the Ag-MnO x /C composites were investigated via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The activity and the stability of the series of Ag-MnO x /C composites toward the oxygen reduction reaction (ORR) in alkaline media were investigated through the electrochemical techniques. The results show that the main species MnO 2 and Ag 2 O in the fresh sample convert into Mn 3 O 4 and Ag(0), respectively, after the heat treatment in N 2 at 300 °C (Ag-MnO x /C-300). The Ag-MnO x /C-300 sample shows the highest activity toward the ORR, with the half-wave potential of the ORR shifting negatively only 0.035 V compared to that on the commercial 40 wt. % Pt/C (JM). The electron transfer number during the ORR on the Ag-MnO x /C composite increases with the value close to four after the heat treatment at 300 °C, which is mainly attributed to the formation of Ag(0), rather than Mn 3 O 4 . The heat treatment brings about a better catalytic stability of the composite, and no obviously negative shift takes place for the half-wave potential of the ORR on the Ag-MnO x /C-300 composite after 1000 cycles accelerated aging test. The maximum power density of the zinc-air battery with the Ag-MnO x /C-300 air electrode reaches up to 130 mW cm −2 , higher than those based on the Pd/C and Pt/C cathode catalysts, which shows that the Ag-MnO x /C-300 composite is a promising candidate as the catalyst for the air electrode

  2. Learning activism, acting with phronesis

    Science.gov (United States)

    Lee, Yew-Jin

    2015-12-01

    The article "Socio-political development of private school children mobilising for disadvantaged others" by Darren Hoeg, Natalie Lemelin, and Lawrence Bencze described a language-learning curriculum that drew on elements of Socioscientific issues and Science, Technology, Society and Environment. Results showed that with a number of enabling factors acting in concert, learning about and engagement in practical action for social justice and equity are possible. An alternative but highly compatible framework is now introduced—phronetic social research—as an action-oriented, wisdom-seeking research stance for the social sciences. By so doing, it is hoped that forms of phronetic social research can gain wider currency among those that promote activism as one of many valued outcomes of an education in science.

  3. Developing metacognition: a basis for active learning

    NARCIS (Netherlands)

    Vos, Henk; de Graaff, E.

    2004-01-01

    The reasons to introduce formats of Active Learning in Engineering (ALE) like project work, problem based learning, use of cases, etc., are mostly based on practical experience and sometimes from applied research on teaching and learning. Such research shows that students learn more and different

  4. Preparation and Characterization of Mn/N Co-Doped TiO2 Loaded on Wood-Based Activated Carbon Fiber and Its Visible Light Photodegradation

    Directory of Open Access Journals (Sweden)

    Xiaojun Ma

    2015-09-01

    Full Text Available Using MnSO4·H2O as manganese source and urea as nitrogen source, Mn/N co-doped TiO2 loaded on wood-based activated carbon fiber (Mn/Ti-N-WACF was prepared by sol–gel method. Mn/Ti-N-WACF with different Mn doping contents was characterized by scanning electron microscopy, X-ray diffraction (XRD and X-ray photoelectron spectroscopies (XPS, and ultraviolet-visible spectrophotometer. Results showed that the loading rate of TiO2 in Mn/Ti-N-WACF was improved by Mn/N co-doping. After calcination at 450 °C, the degree of crystallinity of TiO2 was reduced due to Mn/N co-doption in the resulting Mn/Ti-N-WACF samples, but the TiO2 crystal phase was not changed. XPS spectra revealed that some Ti4+ ions from the TiO2 lattice of Mn/Ti-N-WACF system were substituted by doped Mn. Moreover, new bonds formed within N–Ti–N and Ti–N–O because of the doped N that substituted some oxygen atoms in the TiO2 lattice. Notably, the degradation rate of methylene blue for Mn/Ti-N-WACF was improved because of the co-doped Mn/N under visible-light irradiation.

  5. Binding of Mn-deoxyribonucleoside Triphosphates to the Active Site of the DNA Polymerase of Bacteriophage T7

    Energy Technology Data Exchange (ETDEWEB)

    B Akabayov; C Richardson

    2011-12-31

    Divalent metal ions are crucial as cofactors for a variety of intracellular enzymatic activities. Mg{sup 2+}, as an example, mediates binding of deoxyribonucleoside 5'-triphosphates followed by their hydrolysis in the active site of DNA polymerase. It is difficult to study the binding of Mg{sup 2+} to an active site because Mg{sup 2+} is spectroscopically silent and Mg{sup 2+} binds with low affinity to the active site of an enzyme. Therefore, we substituted Mg{sup 2+} with Mn{sup 2+}:Mn{sup 2+} that is not only visible spectroscopically but also provides full activity of the DNA polymerase of bacteriophage T7. In order to demonstrate that the majority of Mn{sup 2+} is bound to the enzyme, we have applied site-directed titration analysis of T7 DNA polymerase using X-ray near edge spectroscopy. Here we show how X-ray near edge spectroscopy can be used to distinguish between signal originating from Mn{sup 2+} that is free in solution and Mn{sup 2+} bound to the active site of T7 DNA polymerase. This method can be applied to other enzymes that use divalent metal ions as a cofactor.

  6. KatB, a cyanobacterial Mn-catalase with unique active site configuration: Implications for enzyme function.

    Science.gov (United States)

    Bihani, Subhash C; Chakravarty, Dhiman; Ballal, Anand

    2016-04-01

    Manganese catalases (Mn-catalases), a class of H2O2 detoxifying proteins, are structurally and mechanistically distinct from the commonly occurring catalases, which contain heme. Active site of Mn-catalases can serve as template for the synthesis of catalase mimetics for therapeutic intervention in oxidative stress related disorders. However, unlike the heme catalases, structural aspects of Mn-catalases remain inadequately explored. The genome of the ancient cyanobacterium Anabaena PCC7120, shows the presence of two Mn-catalases, KatA and KatB. Here, we report the biochemical and structural characterization of KatB. The KatB protein (with a C-terminal his-tag) was over-expressed in Escherichia coli and purified by affinity chromatography. On the addition of Mn(2+) to the E. coli growth medium, a substantial increase in production of the soluble KatB protein was observed. The purified KatB protein was an efficient catalase, which was relatively insensitive to inhibition by azide. Crystal structure of KatB showed a hexameric assembly with four-helix bundle fold, characteristic of the Ferritin-like superfamily. With canonical Glu4His2 coordination geometry and two terminal water ligands, the KatB active site was distinctly different from that of other Mn-catalases. Interestingly, the KatB active site closely resembled the active sites of ruberythrin/bacterioferritin, bi-iron members of the Ferritin-like superfamily. The KatB crystal structure provided fundamental insights into the evolutionary relationship within the Ferritin-like superfamily and further showed that Mn-catalases can be sub-divided into two groups, each with a distinct active site configuration. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Journaling; an active learning technique.

    Science.gov (United States)

    Blake, Tim K

    2005-01-01

    Journaling is a method frequently discussed in nursing literature and educational literature as an active learning technique that is meant to enhance reflective practice. Reflective practice is a means of self-examination that involves looking back over what has happened in practice in an effort to improve, or encourage professional growth. Some of the benefits of reflective practice include discovering meaning, making connections between experiences and the classroom, instilling values of the profession, gaining the perspective of others, reflection on professional roles, and development of critical thinking. A review of theory and research is discussed, as well as suggestions for implementation of journaling into coursework.

  8. Activation energy of tracer-diffusion of manganese ions (Mn2+) in alkali metal chloride solutions

    International Nuclear Information System (INIS)

    Borhade, A.V.

    2000-01-01

    The activation energy of the tracer diffusion of Mn 2+ ions in alkali chloride solutions (0.1M) has been determined in agar gel medium (1-2.5%) over the temperature range of 25 - 45 deg C. The decrease in the value of the Arrhenius parameters, E and D 0 , with gel percentage is explained on the basis of the transition state theory. Further, the activation energy as a function of electrolyte concentration is also investigated using 1% agar gel in the temperature range of 25 - 45 deg C. In both the cases, the activation energies are determined by the least square fitting of the diffusion coefficient data obtained at various temperatures through the Arrhenius plots. (author)

  9. Reinforcement learning or active inference?

    Science.gov (United States)

    Friston, Karl J; Daunizeau, Jean; Kiebel, Stefan J

    2009-07-29

    This paper questions the need for reinforcement learning or control theory when optimising behaviour. We show that it is fairly simple to teach an agent complicated and adaptive behaviours using a free-energy formulation of perception. In this formulation, agents adjust their internal states and sampling of the environment to minimize their free-energy. Such agents learn causal structure in the environment and sample it in an adaptive and self-supervised fashion. This results in behavioural policies that reproduce those optimised by reinforcement learning and dynamic programming. Critically, we do not need to invoke the notion of reward, value or utility. We illustrate these points by solving a benchmark problem in dynamic programming; namely the mountain-car problem, using active perception or inference under the free-energy principle. The ensuing proof-of-concept may be important because the free-energy formulation furnishes a unified account of both action and perception and may speak to a reappraisal of the role of dopamine in the brain.

  10. Reinforcement learning or active inference?

    Directory of Open Access Journals (Sweden)

    Karl J Friston

    2009-07-01

    Full Text Available This paper questions the need for reinforcement learning or control theory when optimising behaviour. We show that it is fairly simple to teach an agent complicated and adaptive behaviours using a free-energy formulation of perception. In this formulation, agents adjust their internal states and sampling of the environment to minimize their free-energy. Such agents learn causal structure in the environment and sample it in an adaptive and self-supervised fashion. This results in behavioural policies that reproduce those optimised by reinforcement learning and dynamic programming. Critically, we do not need to invoke the notion of reward, value or utility. We illustrate these points by solving a benchmark problem in dynamic programming; namely the mountain-car problem, using active perception or inference under the free-energy principle. The ensuing proof-of-concept may be important because the free-energy formulation furnishes a unified account of both action and perception and may speak to a reappraisal of the role of dopamine in the brain.

  11. Carbon analysis in MOCVD grown HgCdMnTe by charged particle activation

    International Nuclear Information System (INIS)

    Stannard, W.B.; Walker, S.R.; Johnston, P.N.; Bubb, I.F.

    1994-01-01

    Charged Particle Activation Analysis (CPAA) has been used for the determination of the concentration of carbon in HgCdMnTe grown by Metal Organic Chemical Vapour Deposition (MOCVD). The samples were irradiated with a beam of 3.0 MeV 3 He ions. 11 C is produced by the reaction 12 C( 3 He, α) 11 C and is a positron (β + ) emitting radionuclide with a half-life of 20.38 min. At the same time the reaction 16 O( 3 He, p) 18 F produces 18 F which is also a β + emitter and has a half-life of 109.72 min. A post-irradiation etching technique has been developed to enable removal of surface contaminants. The radioactivity is determined by a β + spectrometer consisting of two NaI γ-ray detectors (3x3 in.) oriented at 180 . The two coincident 511 keV γ-rays emitted at 180 during the positron annihilation are detected. The initial 11 C and 18 F activities, and hence the oxygen and carbon contributions, can be separated by analysis of the count rate versus time. Analysis shows significant carbon levels in the HgCdMnTe samples. ((orig.))

  12. Research on Mobile Learning Activities Applying Tablets

    Science.gov (United States)

    Kurilovas, Eugenijus; Juskeviciene, Anita; Bireniene, Virginija

    2015-01-01

    The paper aims to present current research on mobile learning activities in Lithuania while implementing flagship EU-funded CCL project on application of tablet computers in education. In the paper, the quality of modern mobile learning activities based on learning personalisation, problem solving, collaboration, and flipped class methods is…

  13. Active Learning in the Middle Grades

    Science.gov (United States)

    Edwards, Susan

    2015-01-01

    What is active learning and what does it look like in the classroom? If students are participating in active learning, they are playing a more engaged role in the learning process and are not overly reliant on the teacher (Bransford, Brown, & Cocking, 2003; Petress, 2008). The purpose of this article is to propose a framework to describe and…

  14. Incorporating active learning in psychiatry education.

    Science.gov (United States)

    Kumar, Sonia; McLean, Loyola; Nash, Louise; Trigwell, Keith

    2017-06-01

    We aim to summarise the active learning literature in higher education and consider its relevance for postgraduate psychiatry trainees, to inform the development of a new Formal Education Course (FEC): the Master of Medicine (Psychiatry) at the University of Sydney. We undertook a literature search on 'active learning', 'flipped classroom', 'problem-based learning' and 'psychiatry education'. The effectiveness of active learning pedagogy in higher education is well supported by evidence; however, there have been few psychiatry-specific studies. A new 'flipped classroom' format was developed for the Master of Medicine (Psychiatry). Postgraduate psychiatry training is an active learning environment; the pedagogical approach to FECs requires further evaluation.

  15. Magnetic Fe2MO4 (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    International Nuclear Information System (INIS)

    Nguyen, Thi Dung; Phan, Ngoc Hoa; Do, Manh Huy; Ngo, Kim Tham

    2011-01-01

    We present a simple and efficient method for the fabrication of magnetic Fe 2 MO 4 (M:Fe and Mn) activated carbons (Fe 2 MO 4 /AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe 2 MnO 4 /AC-H showed higher catalytic activity in the methyl orange oxidation than Fe 3 O 4 /AC-H. The effect of operational parameters (pH, catalyst loading H 2 O 2 dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  16. Manganese-modified activated carbon fiber (Mn-ACF): Novel efficient adsorbent for Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhumei; Yu, Yichang; Pang, Shiyu; Du, Dongyun, E-mail: dydu666@yahoo.com.cn

    2013-11-01

    In this paper, a novel adsorbent, manganese-modified activated carbon fiber (Mn-ACF), was prepared and used for removal of As(V) from aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Adsorption of As(V) onto the as-prepared adsorbent from aqueous solutions was investigated and discussed. The adsorption kinetic data were modeled using the pseudo-first-order and pseudo-second order, respectively. The experimental results indicate that the pseudo-second-order kinetic equation can better describe the adsorption kinetics. Furthermore, adsorption equilibrium data of As(V) on the as-prepared adsorbent were analyzed by Langmuir and Freundlich models, which suggested that the Langmuir model provides a better correlation of the experimental data. The adsorption capacities (q{sub max}) of As(V) on Mn-ACF at various temperatures, determined using the Langmuir equation, are 23.77, 33.23 and 36.53 mg g{sup −1} at 303, 313 and 323 K, respectively. To the best of our knowledge, this adsorption capacity for As(V) is much larger than those reported in literatures (7.50–16.58 mg g{sup −1}). Notably, the q{sub max} increases with increasing temperature, suggesting that adsorption of As(V) on Mn-ACF surface is an endothermic process, which is further confirmed by the calculated thermodynamic parameters including free energy, enthalpy, and entropy of adsorption process. The effect of experimental parameters such as pH and dosage of adsorbent on adsorption of As(V) were also studied. The present work will be useful in purification of groundwater.

  17. Evaluation of properties of low activation Mn-Cr steel. 1. Mechanical properties and weldability

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Shigeru; Fukaya, Kiyoshi; Ishiyama, Shintaro; Eto, Motokuni [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sato, Ikuo; Kusuhashi, Mikio; Hatakeyama, Takeshi; Takahashi, Heishichiro; Kikuchi, Mitsuru

    1999-10-01

    In JAERI, JT-60SU (Super Upgrade) program is discussed. In the design optimization activity of JT-60SU, it is required for vacuum vessel material to be highly strong, low activated and nonmagnetic. However, there is no suitable material to fulfill all the requirements. Therefore, JAERI started to develop a new material for vacuum vessel together with The Japan Steel Works LTD. (JSW). Chemical composition and production processes were optimized and a new Mn-Cr steel named VC9 with a non-magnetic single {gamma} phase was selected as a candidate material for vacuum vessel of JT-60SU. In this study, characterization of mechanical properties and weldability of VC9 were studied and the results were compared with those of 316L stainless steel. (author)

  18. Evaluation of properties of low activation Mn-Cr steel (2). Physical properties and aging properties

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Shigeru; Fukaya, Kiyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ishiyama, Shintaro [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sato, Ikuo; Kusuhashi, Mikio; Hatakeyama, Takeshi [Japan Steel Works Ltd., Muroran, Hokkaido (Japan). Muroran Plant; Takahashi, Heishichiro [Hokkaido Univ., Sapporo (Japan); Kikuchi, Mitsuru [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2000-08-01

    The JT-60SU (Super Upgrade) program is under discussion at JAERI. Its design optimization activity requires the vacuum vessel material to be non-magnetic, very strong and with low induced activation. However, there is no suitable material available to fulfill all the requirements. JAERI started to develop a new material for the vacuum vessel together with the Japan Steel Works LTD. (JSW). Chemical composition and metallurgical processes were optimized and a new steel named VC9, which has the composition of Cr :16wt%, Mn :15.5wt%, C :0.2wt%, N :0.2wt% with nonmagnetic single {gamma} phase, was selected as a candidate material. Here, physical properties and aging properties of VC9 were studied and the results were compared with those of 316L stainless steel. (author)

  19. Neutron activation analysis of trace metals in the hair and organs of small animals treated chronically with Hg and Mn

    International Nuclear Information System (INIS)

    Ohmori, S.; Hashimoto, K.

    1985-01-01

    For the purpose of studying the secretion of exogenous toxic metals into hair, the relation between their concenrations in hair and in organs, and the metal shift Hg or Mn was orally administered to Guinea pigs for protracted periods. The distributions of metals in hair and organs were examined by means of neutron activation analysis. It was found that the administration of Hg at high dose resulted in abnormally high Hg levels in hair from the 2nd dosing week and in organs after 25 weeks of dosing, and in a reduced motor activity after 25 weeks of administration. There occurred metal shifts in hair as well. Administration of Mn at high doses, on the other hand, showed no such biological influences, although a dose-dependent increase of Mn in hair was detected with time. (author)

  20. Evaluation of properties of low activation Mn-Cr steel. 3. Evaluation of corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Shigeru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Fukaya, Kiyoshi [Nihon Advanced Technology Co., Ltd., Tokai, Ibaraki (Japan); Ishiyama, Shintaro [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sato, Ikuo; Kusuhashi, Mikio; Hatakeyama, Takeshi [Japan Steel Works Ltd., Muroran, Hokkaido (Japan). Muroran Plant; Takahashi, Heishichiro [Hokkaido Univ., Sapporo, Hokkaido (Japan); Kikuchi, Mitsuru [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2002-05-01

    JAERI and the Japan Steel Works LTD. (JSW) have developed new Mn-Cr steels as low induced activation material. Until now, chemical composition and metallurgical processes were optimized and some steels named VC-series were selected. The properties of the steels have been evaluated and reported elsewhere. In this study, corrosion resistance of VC-series was studied. Corrosion tests for stainless steels were performed to investigate a relationship between corrosion rate and chemical composition or sensitization. Furthermore, corrosion tests under actual environment for the vacuum vessel of the reinforced JT-60 were done for non-magnetic steels. As a result, almost no weight change was observed for uniform and gap corrosion tests, No crack was shown for double U-bend corrosion tests. (author)

  1. Creation of a 3Mn/1Fe cluster in the oxygen-evolving complex of photosystem II and investigation of its functional activity.

    Science.gov (United States)

    Semin, B К; Davletshina, L N; Seibert, M; Rubin, A B

    2018-01-01

    Extraction of Mn cations from the oxygen-evolving complex (OEC) of Ca-depleted PSII membranes (PSII[-Ca,4Mn]) by reductants like hydroquinone (H 2 Q) occurs with lower efficiency at acidic pH (2Mn/reaction center [RC] are extracted at pH5.7) than at neutral pH (3Mn/RC are extracted at pH6.5) [Semin et al. Photosynth. Res. 125 (2015) 95]. Fe(II) also extracts Mn cations from PSII(-Ca,4Mn), but only 2Mn/RC at pH6.5, forming a heteronuclear 2Mn/2Fe cluster [Semin and Seibert, J. Bioenerg. Biomembr. 48 (2016) 227]. Here we investigated the efficiency of Mn extraction by Fe(II) at acidic pH and found that Fe(II) cations can extract only 1Mn/RC from PSII(-Ca,4Mn) membranes at pH 5.7, forming a 3Mn/1Fe cluster. Also we found that the presence of Fe cations in a heteronuclear cluster (2Mn/2Fe) increases the resistance of the remaining Mn cations to H 2 Q action, since H 2 Q can extract Mn cations from homonuclear Mn clusters of PSII(-Ca,4Mn) and PSII(-Ca,2Mn) membranes but not from the heteronuclear cluster in PSII(-Ca,2Mn,2Fe) membranes. H 2 Q also cannot extract Mn from PSII membranes obtained by incubation of PSII(-Ca,4Mn) membranes with Fe(II) cations at pH5.7, which suggests the formation of a heteronuclear 3Mn/1Fe cluster in the OEC. Functional activity of PSII with a 3Mn/1Fe cluster was investigated. PSII preparations with a 3Mn/1Fe cluster in the OEC are able to photoreduce the exogenous electron acceptor 2,6-dichlorophenolindophenol, possibly due to incomplete oxidation of water molecules as is the case with PSII(-Ca,2Mn,2Fe) samples. However, in the contrast to PSII(-Ca,2Mn,2Fe) samples PSII(-Ca,3Mn,1Fe) membranes can evolve O 2 at a low rate in the presence of exogenous Ca 2+ (at about 27% of the rate of O 2 evolution in native PSII membranes). The explanation for this phenomenon (either water splitting and production of molecular O 2 by the 3Mn/1Fe cluster or apparent O 2 evolution due to minor contamination of PSII(3Mn,1Fe) samples with PSII(-Ca,4Mn) membranes

  2. Synthesis and characterization of MnS2/reduced graphene oxide nanohybrids for with photocatalytic and antibacterial activity.

    Science.gov (United States)

    Fakhri, Ali; Kahi, Delaram Salehpour

    2017-01-01

    A facile one-step hydrothermal route was developed here to prepare MnS 2 /reduced graphene oxide nanohybrids. The crystal morphologies could be controlled by adjusting the solvent, surfactant, and pH of the precursor solution. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV-Vis absorption spectra, and photoluminescence spectra (PL), were used to characterize the structures of the samples were used to characterize the structures of the samples, and the specific surface area was determined using the Brunauer-Emmett-Teller (BET) method. The thickness of the MnS 2 nanoparticles and MnS 2 /reduced graphene oxide nanohybrids were measured to be about 20 and 5nm, respectively. The total pore volume and specific surface area were 0.540 and 1.173cm 3 g -1 and 45.91 and 98.23m 2 g -1 for pure MnS 2 and MnS 2 /r-GO hybrids, respectively. Carbophenothion as an insecticide photodegradation was used to estimate the photocatalytic activity of the MnS 2 /reduced graphene oxide nanohybrids morphologies under UV light. The Carbophenothion hardly decomposed during photolysis over a period of 45min. The rate constant, k value, for the photocatalysis of Carbophenothion by MnS 2 /reduced graphene oxide nanohybrids under UV light radiation is 0.134min -1 . The antibacterial properties of the nanohybrids were evaluated by determining their minimum inhibitory and bactericidal concentrations (MIC and MBC), using a broth microdilution assay for Escherichia coli (E. coli) bacteria. The MIC and MBC values are 4.0 and 32.0μg/mL. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Architecture for Collaborative Learning Activities in Hybrid Learning Environments

    OpenAIRE

    Ibáñez, María Blanca; Maroto, David; García Rueda, José Jesús; Leony, Derick; Delgado Kloos, Carlos

    2012-01-01

    3D virtual worlds are recognized as collaborative learning environments. However, the underlying technology is not sufficiently mature and the virtual worlds look cartoonish, unlinked to reality. Thus, it is important to enrich them with elements from the real world to enhance student engagement in learning activities. Our approach is to build learning environments where participants can either be in the real world or in its mirror world while sharing the same hybrid space in a collaborative ...

  4. Doing physical activity – not learning

    DEFF Research Database (Denmark)

    Jensen, Jens-Ole

    2017-01-01

    Introduction In recent years there have been a raising critique concerning PE as a subject which is more concerned with keeping pupils physically active than insuring that they learn something (Annerstedt, 2008). In Denmark, this issue has been actualized in a new sense. In 2014, a new school...... reform with 45 minutes of daily physical activity was introduced to enhance the pupils’ health, well-being and learning capabilities. Instead of focusing on learning bodily skills, physical activities has become an instrument to improve learning in the academic subjects. Physical activities.......g. Biesta, 2010; Standal, 2015) I will argue that the focus on learning outcome and effects on physical activity has gone too far in order to reach the objectives. If the notion of ‘keeping pupils physically active’ is understood as a representation of the core quality of physical activity, it seems...

  5. Operando investigation of Au-MnOx thin films with improved activity for the oxygen evolution reaction

    DEFF Research Database (Denmark)

    Frydendal, Rasmus; Seitz, Linsey C.; Sokaras, Dimosthenis

    2017-01-01

    The electrochemical splitting of water holds great potential as a method for producing clean fuels by storing electricity from intermittent energy sources. The efficiency of such a process would be greatly facilitated by incorporating more active catalysts based on abundant materials for the oxygen...... improvement over pure MnOx. These films are characterized with operando X-ray Absorption Spectroscopy, which reveal that Mn assumes a higher oxidation state under reaction conditions when Au is present. The magnitude of the enhancement is correlated to the size of the Au domains, where larger domains...

  6. Influence of ring size on the cognition-enhancing activity of DM235 and MN19, two potent nootropic drugs.

    Science.gov (United States)

    Guandalini, L; Martini, E; Di Cesare Mannelli, L; Dei, S; Manetti, D; Scapecchi, S; Teodori, E; Ghelardini, C; Romanelli, M N

    2012-03-01

    A series of analogs of DM235 and MN19, characterized by rings with different size, have been prepared and evaluated for their nootropic activity in the mouse passive-avoidance test. It was found that the optimal ring size for the analogs of DM235, showing endocyclic both amidic groups, is 6 or 7 atoms. For the compounds structurally related to MN19, carrying an exocyclic amide group, the piperidine ring is the moiety which gives the most interesting compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Student Activity and Learning Outcomes in a Virtual Learning Environment

    Science.gov (United States)

    Romanov, Kalle; Nevgi, Anne

    2008-01-01

    The aim of the study was to explore the relationship between degree of participation and learning outcomes in an e-learning course on medical informatics. Overall activity in using course materials and degree of participation in the discussion forums of an online course were studied among 39 medical students. Students were able to utilise the…

  8. Effect of Mn doped-titania on the activity of metallocene catalyst by in situ ethylene polymerization

    KAUST Repository

    Abdul Kaleel, S. H.; Bahuleyan, Bijal Kottukkal; De, Sadhankumar; Jabarulla Khan, Masihullah; Sougrat, Rachid; Al-Harthi, Mamdouh Ahmed

    2012-01-01

    Ethylene polymerization was carried out using highly active metallocene catalysts (Cp 2ZrCl 2 and Cp 2TiCl 2) in combination with methylalumoxane. Titanium(IV) oxide containing 1% Mn as dopant was used as nanofillers. The influence of filler

  9. Captivate: Building Blocks for Implementing Active Learning

    Science.gov (United States)

    Kitchens, Brent; Means, Tawnya; Tan, Yinliang

    2018-01-01

    In this study, the authors propose a set of key elements that impact the success of an active learning implementation: content delivery, active learning methods, physical environment, technology enhancement, incentive alignment, and educator investment. Through a range of metrics the authors present preliminary evidence that students in courses…

  10. Faculty Perceptions about Barriers to Active Learning

    Science.gov (United States)

    Michael, Joel

    2007-01-01

    Faculty may perceive many barriers to active learning in their classrooms. Four groups of participants in a faculty development workshop were asked to list their perceived barriers to active learning. Many of the problems identified were present on more than one list. The barriers fall into three categories: student characteristics, issues…

  11. Active teaching methods, studying responses and learning

    DEFF Research Database (Denmark)

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain

    2010-01-01

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed....

  12. Active Ageing, Active Learning: Policy and Provision in Hong Kong

    Science.gov (United States)

    Tam, M.

    2011-01-01

    This paper discusses the relationship between ageing and learning, previous literature having confirmed that participation in continued learning in old age contributes to good health, satisfaction with life, independence and self-esteem. Realizing that learning is vital to active ageing, the Hong Kong government has implemented policies and…

  13. Nonspecific bowel activity in imaging inflammation with Tc-99m labelled monoclonal anti-NCA-90 Fab' fragment MN3

    International Nuclear Information System (INIS)

    Ivancevic, V.; Wolter, A.; Munz, D.L.

    2001-01-01

    Since the Tc-99m labelled monoclonal anti-NCA 90 granulocyte antibody Fab' fragment MN3 (MN3 Fab') might be of interest for imaging abdominal inflammation which could be hampered by nonspecific bowel activity, we prospectively investigated the appearance of bowel activity in MN3 Fab' imaging. Methods: Eighty consecutive patients (age range 12-85 years) referred for suspected nonabdominal, mostly musculoskeletal infection, were included. Abdominal inflammation was excluded clinically and there were no signs of inflammatory bowel disease in the patients' histories. One, 5, and 24 hours after introvenous injection of up to 1.1 GBq of MN3 Fab' planar images of the abdomen were performed. Bowel activity was graded visually using a 5-point scale. Results: The one (N = 80), 5 (N = 79), and 24 (N = 52) hour images revealed 46 (10%), 162 (34%), and 173 (55%) accumulating bowel segments, respectively, in 37 (46%), 69 (87%), and 52 (100%) patients. The mean intensity score per accumulating segment was 1.1, 1.8 and 2.7 (p = 0), respectively. Relative frequencies of appearance of the small intestine were 38%, 57%, and 21%, ileocaecal region 6%, 53%, and 48%, ascending colon 5%, 67%, and 89%, transverse colon 1%, 9%, and 69%, descending colon 8%, 15%, and 67%, and rectosigmoid 0%, 4%, and 38%, respectively. Follow-up investigations in 13 patients revealed diverging uptake patterns. Conclusion: Nonspecific bowel activity is often present in the early and almost always and more intense, in the delayed images. Early imaging at one hour after administration seems feasible, but a loss in sensitivity has to be considered. Thus, nonspecific bowel activity can be anticipated to be a pitfall in imaging abdominal inflammation with MN3 Fab'. (orig.) [de

  14. Determination of chemical activities of Fe, Cr, Ni and Mn in stainless steel 316 by Knudsen effusion cell mass spectrometry

    International Nuclear Information System (INIS)

    Venugopal, V.; Kulkarni, S.G.; Subbanna, C.S.; Sood, D.D.

    1995-01-01

    Cold-worked austenitic stainless steel of the type AISI 316 is being used as the cladding and wrapper materials in fast reactor fuel pins. Knowledge of the thermodynamic activities of the steel constituents is necessary to predict the possibility of fuel-cladding, coolant-cladding or fission product-cladding chemical reactions. The thermodynamic activities of Fe, Cr, Ni and Mn for stainless steel 316 were determined by measuring their partial pressures in the temperature range 1293-2120 K, using Knudsen effusion cell mass spectrometry. High purity Ag was used as an internal calibrant. The chemical activities of Fe (a Fe ), Cr (a Cr ), Ni (a Ni ) and Mn (a Mn ) were evaluated using literature data for the vapour pressures of pure metals. log a Fe ±0.18=-1.586+2074/T (T=1293-1872 K)log a Cr ±0.30=-2.350+2612/T (T=1293-2120 K)log a Ni ±0.20=-2.140+1794/T (T=1468-1974 K)log a Mn ±0.23=-2.041-5478/T (T=1302-1894 K) ((orig.))

  15. Comparative kinetic studies of Mn2+-activated and fructose-1,6-P-modified Mg2+-activated pyruvate kinase from Concholepas concholepas.

    Science.gov (United States)

    Carvajal, N; González, R; Morán, A; Oyarce, A M

    1985-01-01

    Initial velocity and product inhibition studies of Mn2+-activated and FDP-modified Mg2+-activated pyruvate kinase from Concholepas concholepas, were performed. Evidence is presented to show that the Mn2+-enzyme catalyzes an ordered sequential mechanism, with ADP being the first substrate and pyruvate the last product. The results presented are consistent with a random combination of reactants with the FDP-modified Mg2+-activated enzyme and the formation of the dead-end complexes enzyme ADP-ATP and enzyme-PEP-ATP.

  16. Direct imaging of thermally-activated grain-boundary diffusion in Cu/Co/IrMn/Pt exchange-bias structures using atom-probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Letellier, F.; Lardé, R.; Le Breton, J.-M., E-mail: jean-marie.lebreton@univ-rouen.fr [Groupe de Physique des Matériaux, UMR 6634 CNRS/Université et INSA de Rouen, F-76801 Saint Etienne du Rouvray (France); Lechevallier, L. [Groupe de Physique des Matériaux, UMR 6634 CNRS/Université et INSA de Rouen, F-76801 Saint Etienne du Rouvray (France); Département de GEII, Université de Cergy-Pontoise, F-95031 Cergy-Pontoise (France); Akmaldinov, K. [SPINTEC, Univ. Grenoble-Alpes/CNRS/INAC-CEA, F-38000 Grenoble (France); CROCUS Technology, F-38025 Grenoble (France); Auffret, S.; Dieny, B.; Baltz, V., E-mail: vincent.baltz@cea.fr [SPINTEC, Univ. Grenoble-Alpes/CNRS/INAC-CEA, F-38000 Grenoble (France)

    2014-11-28

    Magnetic devices are often subject to thermal processing steps, such as field cooling to set exchange bias and annealing to crystallize amorphous magnetic electrodes. These processing steps may result in interdiffusion and the subsequent deterioration of magnetic properties. In this study, we investigated thermally-activated diffusion in Cu/Co/IrMn/Pt exchange biased polycrystalline thin-film structures using atom probe tomography. Images taken after annealing at 400 °C for 60 min revealed Mn diffusion into Co grains at the Co/IrMn interface and along Pt grain boundaries for the IrMn/Pt stack, i.e., a Harrison type C regime. Annealing at 500 °C showed further Mn diffusion into Co grains. At the IrMn/Pt interface, annealing at 500 °C led to a type B behavior since Mn diffusion was detected both along Pt grain boundaries and also into Pt grains. The deterioration of the films' exchange bias properties upon annealing was correlated to the observed diffusion. In particular, the topmost Pt capping layer thickness turned out to be crucial since a faster deterioration of the exchange bias properties for thicker caps was observed. This is consistent with the idea that Pt acts as a getter for Mn, drawing Mn out of the IrMn layer.

  17. Internal exposure to neutron-activated {sup 56}Mn dioxide powder in Wistar rats. Pt. 1. Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Stepanenko, Valeriy; Kaprin, Andrey; Galkin, Vsevolod; Ivanov, Sergey; Kolyzhenkov, Timofey; Petukhov, Aleksey; Yaskova, Elena; Belukha, Irina; Khailov, Artem; Skvortsov, Valeriy; Ivannikov, Alexander; Akhmedova, Umukusum; Bogacheva, Viktoria [Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Obninsk, Kaluga Region (Russian Federation); Rakhypbekov, Tolebay; Dyussupov, Altay; Chaizhunusova, Nailya; Sayakenov, Nurlan; Uzbekov, Darkhan; Saimova, Aisulu; Shabdarbaeva, Dariya; Kairkhanova, Yankar [Semey State Medical University, Semey (Kazakhstan); Otani, Keiko; Endo, Satoru; Satoh, Kenichi; Kawano, Noriyuki; Fujimoto, Nariaki; Hoshi, Masaharu [Hiroshima University, Hiroshima (Japan); Shichijo, Kazuko; Nakashima, Masahiro; Takatsuji, Toshihiro [Nagasaki University, Nagasaki (Japan); Sakaguchi, Aya; Kato, Hiroaki; Onda, Yuichi [University of Tsukuba, Ibaraki (Japan); Toyoda, Shin [Okayama University of Science, Okayama (Japan); Sato, Hitoshi [Ibaraki Prefectural University of Health Science, Ibaraki (Japan); Skakov, Mazhin; Vurim, Alexandr; Gnyrya, Vyacheslav; Azimkhanov, Almas; Kolbayenkov, Alexander [National Nuclear Center of the Republic of Kazakhstan, Kurchatov (Kazakhstan); Zhumadilov, Kasym [Eurasian National University named after L.N. Gumilyov, Astana (Kazakhstan)

    2017-03-15

    There were two sources of ionizing irradiation after the atomic bombings of Hiroshima and Nagasaki: (1) initial gamma-neutron irradiation at the moment of detonation and (2) residual radioactivity. Residual radioactivity consisted of two components: radioactive fallout containing fission products, including radioactive fissile materials from nuclear device, and neutron-activated radioisotopes from materials on the ground. The dosimetry systems DS86 and DS02 were mainly devoted to the assessment of initial radiation exposure to neutrons and gamma rays, while only brief considerations were given for the estimation of doses caused by residual radiation exposure. Currently, estimation of internal exposure of atomic bomb survivors due to dispersed radioactivity and neutron-activated radioisotopes from materials on the ground is a matter of some interest, in Japan. The main neutron-activated radionuclides in soil dust were {sup 24}Na, {sup 28}Al, {sup 31}Si, {sup 32}P, {sup 38}Cl, {sup 42}K, {sup 45}Ca, {sup 46}Sc, {sup 56}Mn, {sup 59}Fe, {sup 60}Co, and {sup 134}Cs. The radionuclide {sup 56}Mn (T{sub 1/2} = 2.58 h) is known as one of the dominant beta- and gamma emitters during the first few hours after neutron irradiation of soil and other materials on ground, dispersed in the form of dust after a nuclear explosion in the atmosphere. To investigate the peculiarities of biological effects of internal exposure to {sup 56}Mn in comparison with external gamma irradiation, a dedicated experiment with Wistar rats exposed to neutron-activated {sup 56}Mn dioxide powder was performed recently by Shichijo and coworkers. The dosimetry required for this experiment is described here. Assessment of internal radiation doses was performed on the basis of measured {sup 56}Mn activity in the organs and tissues of the rats and of absorbed fractions of internal exposure to photons and electrons calculated with the MCNP-4C Monte Carlo using a mathematical rat phantom. The first results of

  18. Scene recognition based on integrating active learning with dictionary learning

    Science.gov (United States)

    Wang, Chengxi; Yin, Xueyan; Yang, Lin; Gong, Chengrong; Zheng, Caixia; Yi, Yugen

    2018-04-01

    Scene recognition is a significant topic in the field of computer vision. Most of the existing scene recognition models require a large amount of labeled training samples to achieve a good performance. However, labeling image manually is a time consuming task and often unrealistic in practice. In order to gain satisfying recognition results when labeled samples are insufficient, this paper proposed a scene recognition algorithm named Integrating Active Learning and Dictionary Leaning (IALDL). IALDL adopts projective dictionary pair learning (DPL) as classifier and introduces active learning mechanism into DPL for improving its performance. When constructing sampling criterion in active learning, IALDL considers both the uncertainty and representativeness as the sampling criteria to effectively select the useful unlabeled samples from a given sample set for expanding the training dataset. Experiment results on three standard databases demonstrate the feasibility and validity of the proposed IALDL.

  19. Simultaneous analysis of Zn, Cu, Mn, In, As and Sb in Zinc concentrates by neutron activation

    International Nuclear Information System (INIS)

    Tenorio, F.; Mendoza, P.; Espinosa, R.

    1986-01-01

    A method has been developed for simultaneous analysis by neutronic activation of Zn, Cu, As, Mn, In and Sb in concentrated minerals of Zn. The method is based entirely on the use of instruments as it does not comprise any chemical treatments. Samples and models are submitted to irradiation for 60 minutes in a flux of thermal neutrons of 1.5x10 n/cm 2 s in the reactor RP-0 of IPEN. The induced activities are measured by gamma spectrometry of high resolution using an intrinsic detector of germanium. One measurement is made immediately after the irradiation of 2000s and another 24 hours after the 3600s irradiation. The interference, the reproductibility, and the limits of detection of each element are discussed. The analytic results of 5 zinc concentrates are compared with the ones obtained by atomic absorption showing excellent concordance. The method is particularly adaptable to portable radioisotope sources of neutrons making it possible to use it in sites such as industrial plants

  20. A Studi on High Plant Systems Course with Active Learning in Higher Education Through Outdoor Learning to Increase Student Learning Activities

    OpenAIRE

    Nur Rokhimah Hanik, Anwari Adi Nugroho

    2015-01-01

    Biology learning especially high plant system courses needs to be applied to active learning centered on the student (Active Learning In Higher Education) to enhance the students' learning activities so that the quality of learning for the better. Outdoor Learning is one of the active learning invites students to learn outside of the classroom by exploring the surrounding environment. This research aims to improve the students' learning activities in the course of high plant systems through t...

  1. Students’ mathematical learning in modelling activities

    DEFF Research Database (Denmark)

    Kjeldsen, Tinne Hoff; Blomhøj, Morten

    2013-01-01

    Ten years of experience with analyses of students’ learning in a modelling course for first year university students, led us to see modelling as a didactical activity with the dual goal of developing students’ modelling competency and enhancing their conceptual learning of mathematical concepts i...... create and help overcome hidden cognitive conflicts in students’ understanding; that reflections within modelling can play an important role for the students’ learning of mathematics. These findings are illustrated with a modelling project concerning the world population....

  2. The Activity Theory Approach to Learning

    Directory of Open Access Journals (Sweden)

    Ritva Engeström

    2014-12-01

    Full Text Available In this paper the author offers a practical view of the theory-grounded research on education action. She draws on studies carried out at the Center for Research on Activity, Development and Learning (CRADLE at the University of Helsinki in Finland. In its work, the Center draws on cultural-historical activity theory (CHAT and is well-known for the theory of Expansive Learning and its more practical application called Developmental Work Research (DWR. These approaches are widely used to understand professional learning and have served as a theoreticaland methodological foundation for studies examining change and professional development in various human activities.

  3. Active learning methods for interactive image retrieval.

    Science.gov (United States)

    Gosselin, Philippe Henri; Cord, Matthieu

    2008-07-01

    Active learning methods have been considered with increased interest in the statistical learning community. Initially developed within a classification framework, a lot of extensions are now being proposed to handle multimedia applications. This paper provides algorithms within a statistical framework to extend active learning for online content-based image retrieval (CBIR). The classification framework is presented with experiments to compare several powerful classification techniques in this information retrieval context. Focusing on interactive methods, active learning strategy is then described. The limitations of this approach for CBIR are emphasized before presenting our new active selection process RETIN. First, as any active method is sensitive to the boundary estimation between classes, the RETIN strategy carries out a boundary correction to make the retrieval process more robust. Second, the criterion of generalization error to optimize the active learning selection is modified to better represent the CBIR objective of database ranking. Third, a batch processing of images is proposed. Our strategy leads to a fast and efficient active learning scheme to retrieve sets of online images (query concept). Experiments on large databases show that the RETIN method performs well in comparison to several other active strategies.

  4. Child Development: An Active Learning Approach

    Science.gov (United States)

    Levine, Laura E.; Munsch, Joyce

    2010-01-01

    Within each chapter of this innovative topical text, the authors engage students by demonstrating the wide range of real-world applications of psychological research connected to child development. In particular, the distinctive Active Learning features incorporated throughout the book foster a dynamic and personal learning process for students.…

  5. Discussing Active Learning from the Practitioner's Perspective

    Science.gov (United States)

    Bamba, Priscilla

    2015-01-01

    The purpose of this paper is to present an overview of how active learning took place in a class containing specific readings,cooperative and collaborative group work, and a writing assignment for college students at a Northern Virginia Community College campus (NVCC). Requisite knowledge, skills, learner characteristics, brain-based learning, and…

  6. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were t...

  7. Removal of 226Ra, Fe3+ and Mn2+ from ground water using modified activated carbon

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.

    2003-01-01

    A locally available biomass material, rice husk, was carbonized and activated in a steam/nitrogen flow by the use of a bench-scale fluidized bed reactor. The virgin carbon prepared from rice husk was further treated chemically using an alkali (e.g.10% NaOH and 10% KOH) in order to change the surface basicity of the carbon or oxidized with 30%H 2 O 2 and 10% HNO 3 in order to introduce different oxygen surface complexes. The modified carbons were characterized by FTIR and elemental analysis and investigated for removing unacceptably high concentrations of 326 Ra from ground water. The results showed that the best removal was obtained by the virgin carbon. The effect of process variables such as: contact time, Ph, carbon mass, sorbent surface modification and cation interference (e.g.iron and manganese) on the removal efficiency by the virgin carbon was studied. The data was fitted to Freundlich adsorption equation. Recommended procedures were adapted for complete removal of 226 Ra, Fe 3+ and Mn 2+ from ground water. Treated water quality remained good and no significant external radiation dose was caused to the residents

  8. Lithium recovery from brine using a λ-MnO2/activated carbon hybrid supercapacitor system.

    Science.gov (United States)

    Kim, Seoni; Lee, Jaehan; Kang, Jin Soo; Jo, Kyusik; Kim, Seonghwan; Sung, Yung-Eun; Yoon, Jeyong

    2015-04-01

    Lithium is one of the most important elements in various fields including energy storage, medicine manufacturing and the glass industry, and demands for lithium are constantly increasing these days. The lime soda evaporation process using brine lake water is the major extraction method for lithium, but this process is not only inefficient and time-consuming but also causes a few environmental problems. Electrochemical recovery processes of lithium ions have been proposed recently, but the better idea for the silver negative electrodes used in these systems is required to reduce its cost or increase long term stability. Here, we report an electrochemical lithium recovery method based on a λ-MnO2/activated carbon hybrid supercapacitor system. In this system, lithium ions and counter anions are effectively captured at each electrode with low energy consumption in a salt solution containing various cationic species or simulated Salar de Atacama brine lake water in Chile. Furthermore, we designed this system as a flow process for practical applications. By experimental analyses, we confirmed that this system has high selectivity and long-term stability, with its performance being retained even after repetitive captures and releases of lithium ions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Learning outcomes between Socioscientific Issues-Based Learning and Conventional Learning Activities

    OpenAIRE

    Piyaluk Wongsri; Prasart Nuangchalerm

    2010-01-01

    Problem statement: Socioscientific issues-based learning activity is essential for scientific reasoning skills and it could be used for analyzing problems be applied to each situation for more successful and suitable. The purposes of this research aimed to compare learning achievement, analytical thinking and moral reasoning of seventh grade students who were organized between socioscientific issues-based learning and conventional learning activities. Approach: The samples used in research we...

  10. Point-of-Purchase Advertising. Learning Activity.

    Science.gov (United States)

    Shackelford, Ray

    1998-01-01

    In this technology education activity, students learn the importance of advertising, conduct a day-long survey of advertising strategies, and design and produce a tabletop point-of-purchase advertisement. (JOW)

  11. Activating teaching methods, studying responses and learning

    OpenAIRE

    Christensen, Hans Peter; Vigild, Martin E.; Thomsen, Erik; Szabo, Peter; Horsewell, Andy

    2009-01-01

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed. Peer Reviewed

  12. Learning Activities in a Sociable Smart City

    Directory of Open Access Journals (Sweden)

    Dimitrios Ringas

    2013-08-01

    Full Text Available We present our approach on how smart city technologies may enhance the learning process. We have developed the CLIO urban computing system, which invites people to share personal memories and interact the collective city memory. Various educational scenarios and activities were performed exploiting CLIO; in this paper we present the methodology we followed and the experience we gained. Learning has always been the cognitive process of acquiring skills or knowledge, while teachers are often eager to experiment with novel technological means and methods; our aim was to explore the effect that urban computing could have to the learning process. We applied our methodology in the city of Corfu inviting schools to engage their students in learning through the collective city memory while exploiting urban computing. Results from our experience demonstrate the potential of exploiting urban computing in the learning process and the benefits of learning out of the classroom.

  13. Dopamine, reward learning, and active inference

    Directory of Open Access Journals (Sweden)

    Thomas eFitzgerald

    2015-11-01

    Full Text Available Temporal difference learning models propose phasic dopamine signalling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behaviour. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings.

  14. Dopamine, reward learning, and active inference.

    Science.gov (United States)

    FitzGerald, Thomas H B; Dolan, Raymond J; Friston, Karl

    2015-01-01

    Temporal difference learning models propose phasic dopamine signaling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behavior. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings.

  15. People with Learning Disabilities and "Active Ageing"

    Science.gov (United States)

    Foster, Liam; Boxall, Kathy

    2015-01-01

    Background: People (with and without learning disabilities) are living longer. Demographic ageing creates challenges and the leading policy response to these challenges is "active ageing". "Active" does not just refer to the ability to be physically and economically active, but also includes ongoing social and civic engagement…

  16. Teaching Engineering with Autonomous Learning Activities

    Science.gov (United States)

    Otero, Beatriz; Rodríguez, Eva; Royo, Pablo

    2015-01-01

    This paper proposes several activities that encourage self-learning in engineering courses. For each activity, the context and the pedagogical issues addressed are described emphasizing strengths and weaknesses. Specifically, this work describes and implements five activities, which are: questionnaires, conceptual maps, videos, jigsaw and…

  17. Active Learning through Online Instruction

    Science.gov (United States)

    Gulbahar, Yasemin; Kalelioglu, Filiz

    2010-01-01

    This article explores the use of proper instructional techniques in online discussions that lead to meaningful learning. The research study looks at the effective use of two instructional techniques within online environments, based on qualitative measures. "Brainstorming" and "Six Thinking Hats" were selected and implemented…

  18. Study of multiplet structures of Mn4+ activated in fluoride crystals

    International Nuclear Information System (INIS)

    Novita, Mega; Honma, Tetsuo; Hong, Byungchul; Ohishi, Atsushi; Ogasawara, Kazuyoshi

    2016-01-01

    We investigated the optical properties of Mn 4+ in some fluoride crystals such as Cs 2 MnF 6 , Cs 2 GeF 6 , Rb 2 GeF 6 , Cs 2 SiF 6 , K 2 SiF 6 , Rb 2 MnF 6 , Rb 2 SiF 6 , K 2 GeF 6 , K 2 TiF 6 , Li 2 MnF 6 , Na 2 GeF 6 , Na 2 SiF 6 , and Na 2 TiF 6 based on the first-principle calculation using the discrete-variational multi-electron method. In order to estimate the lattice relaxation, we performed EXAFS measurement of Mn 4+ doped in K 2 SiF 6 , K 2 TiF 6 , and K 2 GeF 6 . The relaxation rates of A 2 BF 6 :Mn 4+ were fixed to be the above estimated values, 102.24%, 107.37% or 96.80% for crystal having Si, Ge, or Ti at the B cation site, respectively. In this work, we also considered some corrections such as configuration dependent correction and correlation correction to improve the theoretical energies. It has been shown that to reproduce multiplet energy levels quantitatively, the lattice relaxation is very important. On the other hand, for a qualitative prediction of the tendencies of the multiplet energies, the combination of lattice relaxation effect, configuration dependent correction, and correlation correction is effective. - Highlights: • Multiplet structures of A 2 BF 6 :Mn 4+ were calculated from first-principles. • Lattice relaxation was estimated based on EXAFS experiment. • Lattice relaxation is important to reproduce multiplet energies quantitatively. • CDC and CC are important to reproduce tendencies of multiplet energies.

  19. Automatic Earthquake Detection by Active Learning

    Science.gov (United States)

    Bergen, K.; Beroza, G. C.

    2017-12-01

    In recent years, advances in machine learning have transformed fields such as image recognition, natural language processing and recommender systems. Many of these performance gains have relied on the availability of large, labeled data sets to train high-accuracy models; labeled data sets are those for which each sample includes a target class label, such as waveforms tagged as either earthquakes or noise. Earthquake seismologists are increasingly leveraging machine learning and data mining techniques to detect and analyze weak earthquake signals in large seismic data sets. One of the challenges in applying machine learning to seismic data sets is the limited labeled data problem; learning algorithms need to be given examples of earthquake waveforms, but the number of known events, taken from earthquake catalogs, may be insufficient to build an accurate detector. Furthermore, earthquake catalogs are known to be incomplete, resulting in training data that may be biased towards larger events and contain inaccurate labels. This challenge is compounded by the class imbalance problem; the events of interest, earthquakes, are infrequent relative to noise in continuous data sets, and many learning algorithms perform poorly on rare classes. In this work, we investigate the use of active learning for automatic earthquake detection. Active learning is a type of semi-supervised machine learning that uses a human-in-the-loop approach to strategically supplement a small initial training set. The learning algorithm incorporates domain expertise through interaction between a human expert and the algorithm, with the algorithm actively posing queries to the user to improve detection performance. We demonstrate the potential of active machine learning to improve earthquake detection performance with limited available training data.

  20. Preparation of ErMnO3 by Sol-gel Method and its Photocatalytic Activity for Removal of Methyl Orange from Water

    Science.gov (United States)

    Xie, X. Y.; Yang, J. N.; Yu, L. L.; Min, J. Y.; Sun, D. D.; Tang, P. S.; Chen, H. F.

    2018-05-01

    The single phase perovskite ErMnO3 was synthesized using Er(NO3)3, manganese acetate, citric acid and urea by a facile sol-gel method. The gel of ErMnO3 precursor was kept for 36 hours in 100 °C oven to get the xerogel. Then, the xerogel was calcined at 800 °C for 12 hours in muffle furnace to prepare single phase ErMnO3. The prepared sample was characterized by thermogravimetry differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Under ultraviolet light, the photocatalytic activity of ErMnO3 was studied with methyl orange of 20 mg/L as the simulated sewage. The results show that the ErMnO3 sample particle size distribution is relatively uniform, the average grain size is mainly around 100 nm. The photocatalytic experiment demonstrates that ErMnO3 is highly photocatalytic activity for removal of methyl orange from water. When methyl orange of 20 mg/L is degraded for 120 min in the presence of ErMnO3, the degradation rate of methyl orange can reach about 95%. The degradation of methyl orange accords with first order kinetic model in presence ErMnO3 sample, and the apparent rate constant is 0.022 min-1.

  1. Engineering of a novel tri-functional enzyme with MnSOD, catalase and cell-permeable activities.

    Science.gov (United States)

    Luangwattananun, Piriya; Yainoy, Sakda; Eiamphungporn, Warawan; Songtawee, Napat; Bülow, Leif; Ayudhya, Chartchalerm Isarankura Na; Prachayasittikul, Virapong

    2016-04-01

    Cooperative function of superoxide dismutase (SOD) and catalase (CAT), in protection against oxidative stress, is known to be more effective than the action of either single enzyme. Chemical conjugation of the two enzymes resulted in molecules with higher antioxidant activity and therapeutic efficacy. However, chemical methods holds several drawbacks; e.g., loss of enzymatic activity, low homogeneity, time-consuming, and the need of chemical residues removal. Yet, the conjugated enzymes have never been proven to internalize into target cells. In this study, by employing genetic and protein engineering technologies, we reported designing and production of a bi-functional protein with SOD and CAT activities for the first time. To enable cellular internalization, cell penetrating peptide from HIV-1 Tat (TAT) was incorporated. Co-expression of CAT-MnSOD and MnSOD-TAT fusion genes allowed simultaneous self-assembly of the protein sequences into a large protein complex, which is expected to contained one tetrameric structure of CAT, four tetrameric structures of MnSOD and twelve units of TAT. The protein showed cellular internalization and superior protection against paraquat-induced cell death as compared to either complex bi-functional protein without TAT or to native enzymes fused with TAT. This study not only provided an alternative strategy to produce multifunctional protein complex, but also gained an insight into the development of therapeutic agent against oxidative stress-related conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Manifold Regularized Experimental Design for Active Learning.

    Science.gov (United States)

    Zhang, Lining; Shum, Hubert P H; Shao, Ling

    2016-12-02

    Various machine learning and data mining tasks in classification require abundant data samples to be labeled for training. Conventional active learning methods aim at labeling the most informative samples for alleviating the labor of the user. Many previous studies in active learning select one sample after another in a greedy manner. However, this is not very effective because the classification models has to be retrained for each newly labeled sample. Moreover, many popular active learning approaches utilize the most uncertain samples by leveraging the classification hyperplane of the classifier, which is not appropriate since the classification hyperplane is inaccurate when the training data are small-sized. The problem of insufficient training data in real-world systems limits the potential applications of these approaches. This paper presents a novel method of active learning called manifold regularized experimental design (MRED), which can label multiple informative samples at one time for training. In addition, MRED gives an explicit geometric explanation for the selected samples to be labeled by the user. Different from existing active learning methods, our method avoids the intrinsic problems caused by insufficiently labeled samples in real-world applications. Various experiments on synthetic datasets, the Yale face database and the Corel image database have been carried out to show how MRED outperforms existing methods.

  3. Experimental study on Hg{sup 0} removal from flue gas over columnar MnO{sub x}-CeO{sub 2}/activated coke

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yine [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); Li, Caiting, E-mail: ctli@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); Zhao, Lingkui; Zhang, Jie; Zeng, Guangming; Zhang, Xunan; Zhang, Wei; Tao, Shasha [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)

    2015-04-01

    Highlights: • The Hg{sup 0} removal efficiency over columnar MnCe6/activated coke up to 94%. • MnO{sub x} and CeO{sub 2} exhibited a significant synergistic role in Hg{sup 0} removal over MnCe/AC. • Lattice oxygen, chemisorbed oxygen and OH groups on the surface of MnCe/AC contributed to Hg{sup 0} oxidation. • Hg{sup 0} removal mechanisms over MnCe/AC were identified firstly. - Abstract: Mn-Ce mixed oxides supported on commercial columnar activated coke (MnCe/AC) were employed to remove elemental mercury (Hg{sup 0}) at low temperatures (100–250 °C) without the assistance of HCl in flue gas. The samples were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Effects of some factors, including Mn-Ce loading values, active component, reaction temperatures and flue gas components (O{sub 2}, SO{sub 2}, NO, H{sub 2}O), on Hg{sup 0} removal efficiency were investigated. Results indicated that the optimal Mn-Ce loading value and reaction temperature were 6% and 190 °C, respectively. Considerable high Hg{sup 0} removal efficiency (>90%) can be obtained over MnCe6/AC under both N{sub 2}/O{sub 2} atmosphere and simulated flue gas atmosphere at 190 °C. Besides, it was observed that O{sub 2} and NO exerted a promotional effect on Hg{sup 0} removal, H{sub 2}O exhibited a suppressive effect, and SO{sub 2} hindered Hg{sup 0} removal seriously when in the absence of O{sub 2}. Furthermore, the XPS spectra of Hg 4f and Hg-TPD results showed that the captured mercury were existed as Hg{sup 0} and HgO on the MnCe6/AC, and HgO was the major species, which illustrated that adsorption and catalytic oxidation process were included for Hg{sup 0} removal over MnCe6/AC, and catalytic oxidation played the critical role. What's more, both lattice oxygen and chemisorbed oxygen or OH groups on MnCe6/AC contributed to Hg{sup 0} oxidation. MnCe6/AC, which exhibited

  4. AMP-activated protein kinase controls exercise training- and AICAR-induced increases in SIRT3 and MnSOD

    Directory of Open Access Journals (Sweden)

    Josef eBrandauer

    2015-03-01

    Full Text Available The mitochondrial protein deacetylase sirtuin (SIRT 3 may mediate exercise training-induced increases in mitochondrial biogenesis and improvements in reactive oxygen species (ROS handling. We determined the requirement of AMP-activated protein kinase (AMPK for exercise training-induced increases in skeletal muscle abundance of SIRT3 and other mitochondrial proteins. Exercise training for 6.5 weeks increased SIRT3 (p<0.01 and superoxide dismutase 2 (MnSOD; p<0.05 protein abundance in quadriceps muscle of wild-type (WT; n=13-15, but not AMPK α2 kinase dead (KD; n=12-13 mice. We also observed a strong trend for increased MnSOD abundance in exercise-trained skeletal muscle of healthy humans (p=0.051; n=6. To further elucidate a role for AMPK in mediating these effects, we treated WT (n=7-8 and AMPK α2 KD (n=7-9 mice with 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide (AICAR. Four weeks of daily AICAR injections (500 mg/kg resulted in AMPK-dependent increases in SIRT3 (p<0.05 and MnSOD (p<0.01 in WT, but not AMPK α2 KD mice. We also tested the effect of repeated AICAR treatment on mitochondrial protein levels in mice lacking the transcriptional coactivator peroxisome proliferator-activated receptor γ-coactivator 1α (PGC-1α KO; n=9-10. Skeletal muscle SIRT3 and MnSOD protein abundance was reduced in sedentary PGC-1α KO mice (p<0.01 and AICAR-induced increases in SIRT3 and MnSOD protein abundance was only observed in WT mice (p<0.05. Finally, the acetylation status of SIRT3 target lysine residues on MnSOD (K122 or oligomycin-sensitivity conferring protein (OSCP; K139 was not altered in either mouse or human skeletal muscle in response to acute exercise. We propose an important role for AMPK in regulating mitochondrial function and ROS handling in skeletal muscle in response to exercise training.

  5. Enhanced adsorption of chromium onto activated carbon by microwave-assisted H{sub 3}PO{sub 4} mixed with Fe/Al/Mn activation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuanyuan [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Yue, Qinyan, E-mail: qyyue58@aliyun.com [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Mao, Yanpeng [School of Energy and Power Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu; Gao, Yuan; Huang, Lihui [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China)

    2014-01-30

    Highlights: • FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activator to produce carbons. • Doping with MnCl{sub 2} was favorable for the enlargement of activated carbon. • The assisted activator had good performance for holding more fixed carbon. • The maximum adsorption capacities followed the order of AC-Fe > AC-Al > AC-Mn > AC. • The XPS analysis was used to confirm the adsorption/transformation mechanism. -- Abstract: FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activation agent in activated carbon preparation by H{sub 3}PO{sub 4} activation using microwave heating method. The physico-chemical properties of activated carbons were investigated by scanning electron microscope (SEM), N{sub 2} adsorption/desorption, Boehm's titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). To investigate the adsorption performances of chromium onto these newly developed activated carbons, a batch of experiments were performed under different adsorption conditions: solution pH, initial Cr(VI) ion concentration, contact time and co-existing ions. The results suggested that carbon with MnCl{sub 2} as assisted activation agent displayed the highest BET surface area (1332 m{sup 2}/g) and the highest pore volume (1.060 cm{sup 3}/g). FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} had successfully improved Cr(VI) adsorption and activated carbon with FeCl{sub 3} as assisted activation agent exhibited the best uptake capacity. To study the transformation of Cr(VI) in adsorption process, total chromium in the aqueous solution was also recorded. The ratio of the amount of Cr(VI) to Cr(III) on each adsorbent was explained by XPS analysis results. Both the co-existing salts (Na{sub 2}SO{sub 4} and NaNO{sub 3}) demonstrated promoted effects on Cr(VI) removal by four carbons. The pseudo-second-order model and Freundlich equation displayed a good correlation with

  6. Quantum Speedup for Active Learning Agents

    Directory of Open Access Journals (Sweden)

    Giuseppe Davide Paparo

    2014-07-01

    Full Text Available Can quantum mechanics help us build intelligent learning agents? A defining signature of intelligent behavior is the capacity to learn from experience. However, a major bottleneck for agents to learn in real-life situations is the size and complexity of the corresponding task environment. Even in a moderately realistic environment, it may simply take too long to rationally respond to a given situation. If the environment is impatient, allowing only a certain time for a response, an agent may then be unable to cope with the situation and to learn at all. Here, we show that quantum physics can help and provide a quadratic speedup for active learning as a genuine problem of artificial intelligence. This result will be particularly relevant for applications involving complex task environments.

  7. Characterization and Catalytic Activity of Mn-Co/TiO2 Catalysts for NO Oxidation to NO2 at Low Temperature

    Directory of Open Access Journals (Sweden)

    Lu Qiu

    2016-01-01

    Full Text Available A series of Mn-Co/TiO2 catalysts were prepared by wet impregnation method and evaluated for the oxidation of NO to NO2. The effects of Co amounts and calcination temperature on NO oxidation were investigated in detail. The catalytic oxidation ability in the temperature range of 403–473 K was obviously improved by doping cobalt into Mn/TiO2. These samples were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, transmission electron microscope (TEM and hydrogen temperature programmed reduction (H2-TPR. The results indicated that the formation of dispersed Co3O4·CoMnO3 mixed oxides through synergistic interaction between Mn-O and Co-O was directly responsible for the enhanced activities towards NO oxidation at low temperatures. Doping of Co enhanced Mn4+ formation and increased chemical adsorbed oxygen amounts, which also accelerated NO oxidation.

  8. Learning, Learning Analytics, Activity Visualisation and Open learner Model

    DEFF Research Database (Denmark)

    Bull, Susan; Kickmeier-Rust, Michael; Vatrapu, Ravi

    2013-01-01

    This paper draws on visualisation approaches in learning analytics, considering how classroom visualisations can come together in practice. We suggest an open learner model in situations where many tools and activity visualisations produce more visual information than can be readily interpreted....

  9. A Learning Activity Design Framework for Supporting Mobile Learning

    Directory of Open Access Journals (Sweden)

    Jalal Nouri

    2016-01-01

    Full Text Available This article introduces the Learning Activity Design (LEAD framework for the development and implementation of mobile learning activities in primary schools. The LEAD framework draws on methodological perspectives suggested by design-based research and interaction design in the specific field of technology-enhanced learning (TEL. The LEAD framework is grounded in four design projects conducted over a period of six years. It contributes a new understanding of the intricacies and multifaceted aspects of the design-process characterizing the development and implementation of mobile devices (i.e. smart phones and tablets in curricular activities conducted in Swedish primary schools. This framework is intended to provide both designers and researchers with methodological tools that take account of the pedagogical foundations of technologically-based educational interventions, usability issues related to the interaction with the mobile application developed, multiple data streams generated during the design project, multiple stakeholders involved in the design process and sustainability aspects of the mobile learning activities implemented in the school classroom.

  10. Effect of iron content on the catalytic activity of Fe-MnOx electrodeposited films in water oxidation

    Science.gov (United States)

    Selinger, Elizabeth; Ryczko, Kevin; Lopinski, Gregory; Armandi, Marco; Bonelli, Barbara; Tamblyn, Isaac

    We report on the experimental and computational optimization and characterization of an MnOx structure containing a small amount of Fe, used as a catalyst for the water oxidation reaction (WOR), the key limiting reaction in water splitting. MnOx materials are earth-abundant and known to be efficient for WOR, and the method of cathodically electrodepositing catalysts allows for quick synthesis and a homogeneous coverage of the substrate. We present an increase in WOR activity due to the presence of Fe in this MnOx catalyst structure. First, we explored the optimal range for Fe(NO3)3 concentration in an KMnO4 solution for electrodeposition and tested for WOR activity. The catalyst structure was then analyzed using FESEM, XPS, and a Kelvin probe. We then developed a computational model of this structure, using density functional theory to obtain adsorption energies, work functions, projected density of states, and Born-Oppenheimer molecular dynamics. In this theoretical framework, we explore how these observables change with respect to concentration of Fe, and compare the theoretical model with experiment. special acknowledgement to the Italian Cultural Centre of Durham scholarship program.

  11. Epoxy-bonded La(Fe,mn,si)13Hz As A Multi Layered Active Magnetic Regenerator

    DEFF Research Database (Denmark)

    Neves Bez, Henrique; Navickaité, Kristina; Lei, Tian

    2016-01-01

    of the material may break apart during operation. In this context, we studied epoxy-bonded La(Fe,Mn,Si)13Hz regenerators, in a small versatile active magnetic regeneration (AMR) test device with a 1.1 T permanent magnet source. The magnetocaloric material was in the form of packed irregular particles (250-500 µm......The high magnetocaloric effect and tunability of the Curie temperature over a broad range makes La(Fe,Mn,Si)13Hz a promising magnetocaloric material for applications. Due to a volume change across the transition and the brittleness of the material as well as erosion due to fluid flow, the particles......), which were mechanically held in place by an epoxy matrix connecting the particles, improving the mechanical integrity, while allowing a continuous porosity for the fluid flow. Water with 2 wt% ENTEK FNE as anti-corrosion additive was used as the heat transfer fluid for the epoxy-bonded regenerators...

  12. Determination of Cobalt in Seawater Using Neutron Activation Analysis after Preconcentration by Adsorption onto γ-MnO2 Nanomaterial

    Directory of Open Access Journals (Sweden)

    Van-Phuc Dinh

    2018-01-01

    Full Text Available The γ-MnO2 nanomaterial has been used to adsorb cobalt in the seawater at Phan Thiet City, Binh Thuan Province, Vietnam. Its concentration is determined by using the neutron activation analysis (NAA method at the Dalat nuclear research reactor. Factors affecting the uptake of cobalt on the γ-MnO2 material such as the pH, adsorption time, and initial cobalt(II concentration are investigated. The irradiated experiment data are calculated using the K0-Dalat program. The results obtained show that the trace dissolved cobalt in Phan Thiet seawater is found equal to 0.25 ± 0.04 μg/L (n=5, P=95% with the adsorption efficiency being higher than 95% (n=4, P=95%.

  13. Oral Hygiene. Instructor's Packet. Learning Activity Package.

    Science.gov (United States)

    Hime, Kirsten

    This instructor's packet accompanies the learning activity package (LAP) on oral hygiene. Contents included in the packet are a time sheet, suggested uses for the LAP, an instruction sheet, final LAP reviews, a final LAP review answer key, suggested activities, additional resources (student handouts), student performance checklists for both…

  14. Building Maintenance. Math Learning Activity Packet.

    Science.gov (United States)

    Grant, Shelia I.

    This collection of learning activities is intended for use in reinforcing mathematics instruction as it relates to building maintenance. Fifty activity sheets are provided. These are organized into units on the following topics: numeration, adding whole numbers, subtracting whole numbers, multiplying whole numbers, dividing whole numbers,…

  15. Grooming. Instructor's Packet. Learning Activity Package.

    Science.gov (United States)

    Stark, Pamela

    This instructor's packet accompanies the learning activity package (LAP) on grooming. Contents included in the packet are a time sheet, suggested uses for the LAP, an instruction sheet, final LAP reviews, a final LAP review answer key, suggested activities, an additional resources list, and student completion cards to issue to students as an…

  16. The Effect of Different Levels of Cu, Zn and Mn Nanoparticles in Hen Turkey Diet on the Activity of Aminopeptidases.

    Science.gov (United States)

    Jóźwik, Artur; Marchewka, Joanna; Strzałkowska, Nina; Horbańczuk, Jarosław Olav; Szumacher-Strabel, Małgorzata; Cieślak, Adam; Lipińska-Palka, Paulina; Józefiak, Damian; Kamińska, Agnieszka; Atanasov, Atanas G

    2018-05-11

    The aim of the study was to estimate the influence of the different levels of Cu, Zn, and Mn nanoparticles on the activity of aminopeptidases in turkey. An experiment was carried out on 144 turkey hen Hybrid Converter. The birds were divided into groups given standard- and nanoparticle-supplementation of different level of copper (Cu 20, 10, 2 mg/kg), zinc (Zn 100, 50, 10 ppm), and manganese (Mn 100, 50, 10 ppm), covering respectively 100%, 50%, and 10% of the physiological demands for those minerals in the diet. The activity of aminopeptidases (alanyl: AlaAP, leucyl: LeuAP and arginyl: ArgAP) after supplementation of minerals was determined in the breast and thigh turkey muscle. The strongest effect of interaction among minerals supplementation form and dose on the activity levels of the aminopeptidases in thigh muscle was observed for nano-Cu already at the lowest dose of 2 mg/kg. In this dose (covering 10% of the birds’ demand) nano form of supplementation significantly increased the activity of Ala-, Leu-, and ArgAP (877, 201, and 719, respectively), compared to standard form of supplementation (461, 90.5, and 576, respectively). In turn, in breast muscle, after supplementation covering 10% of the demand with the nano-Cu, nano-Zn, and nano-Mn compared to the standard form, we did not observe any significant difference in the activity levels of any of the investigated aminopeptidases, except for AlaAP under Zn supplementation. Supplementation with the 20 mg/kg of Nano-Cu (100% of demand) and with 10 mg/kg of Nano-Cu (50% of demand) inhibited the activity of all of the three aminopeptidases in thigh muscle. Supplementation of the minerals in nano form into the diet, especially of Cu and Zn in the dose covering 10% of the demand is relevant to maintain homeostasis in turkey muscles, as indicated by the activity of the aminopeptidases.

  17. Activating Teaching for Quality Learning

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy

    2013-01-01

    Activating teaching is an educational concept which is based on active participation of students in the study process. It is becoming an alternative to more typical approach where the teacher will just lecture and the students will take notes. The study described in this paper considers student...... activating teaching methods focusing on those based on knowledge dissemination. The practical aspects of the implemented teaching method are considered, and employed assessment methods and tools are discussed....

  18. Active learning in practice: Implementation of the principles of active learning in an engineering course

    DEFF Research Database (Denmark)

    Rützou, C.

    2017-01-01

    The most common form of teaching is still the form where a teacher presents the subject of the lecture to a listening audience. During teaching history this has proved to be an effective way of teaching, however the probability of students being inactive is high and the learning outcome may...... through the same curriculum as usual during a term? • Will Active Learning reduce failure rate? • Will Active Learning give a higher learning outcome than traditional teaching? This paper deals with the results of this experiment, answers the mentioned questions and presents a way to implement Active...

  19. Is Peer Interaction Necessary for Optimal Active Learning?

    Science.gov (United States)

    Linton, Debra L.; Farmer, Jan Keith; Peterson, Ernie

    2014-01-01

    Meta-analyses of active-learning research consistently show that active-learning techniques result in greater student performance than traditional lecture-based courses. However, some individual studies show no effect of active-learning interventions. This may be due to inexperienced implementation of active learning. To minimize the effect of…

  20. Reduced-activation austenitic stainless steels: The Fe--Mn--Cr--C system

    International Nuclear Information System (INIS)

    Klueh, R.L.; Maziasz, P.J.

    1988-01-01

    Nickel-free manganese-stabilized steels are being developed for fusion-reactor applications. As the first part of this effort, the austenite-stable region in the Fe--Mn--Cr--C system was determined. Results indicated that the Schaeffler diagram developed for Fe--Ni--Cr--C alloys cannot be used to predict the constituents expected for high-manganese steels. This is true because manganese is not as strong an austenite stabilizer relative to δ-ferrite formation as predicted by the diagram, but it is a stronger austenite stabilizer relative to martensite than predicted. Therefore, the austenite-stable region for Ne--Mn--Cr--C alloys occurs at lower chromium and hugher combinations of manganese and carbon than predicted by the Schaeffler diagram. Development of a manganese-stabilized stainless steel should be possible in the composition range of 20 to 25% Mn, 10 to 15% Cr, and 0.01 to 0.25%C. Tensile behavior of an Fe--20%Mn--12%Cr--0.25%C alloy was determined. The strength and ductility of this possible base composition was comparable to type 316 stainless steel in both the solution-annealed and cold-worked condition

  1. Determination of V, W and Mn in high-speed steel by neutron activation source of 241Am/Be

    International Nuclear Information System (INIS)

    Villar, H.P.; Galdino, S.M.L.; Godoy, M.O.; Dantas, C.C.

    1982-01-01

    Alloying elements are responsible for certain characteristics of the steels which enable their utilization for specific purposes. The concentrations of these elements must comply with strict standards, and the determination of these concentrations involve chemical analyses which are as a rule tedious and expensive. It is proposed here a fast and precise analytical process based on the neutron activation analysis. A significant correlation (r = 0.998) between manganese concentration and mean specific count rate of 56 Mn was obtained for activated tool steel samples. Later on, bases for tungsten vanadium determinations were set. (Author) [pt

  2. Determination of V, W and Mn in fast steels by neutron activation analysis of 241Am/Be source

    International Nuclear Information System (INIS)

    Villar, H.P.; Galdino, S.M.L.; Godoy, M.O.; Dantas, C.C.

    1982-01-01

    Alloying elements are responsible for certain characteristics of the steels which enable their utilization for specific purposes. The concentrations of these elements must comply with strict standards, and the determination of these concentrations involve chemical analyses which are as a rule tedious and expensive. It is proposed here a fast and precise analytical process based on the neutron activation analysis. A significant correlation (r = 0.998) between manganese concentration and mean specific count rate of 56 Mn was obtained for activated tool steel sampes. Later on, bases for tungsten vanadium determinations were set. (Author) [pt

  3. Learning plan applicability through active mental entities

    International Nuclear Information System (INIS)

    Baroni, Pietro; Fogli, Daniela; Guida, Giovanni

    1999-01-01

    This paper aims at laying down the foundations of a new approach to learning in autonomous mobile robots. It is based on the assumption that robots can be provided with built-in action plans and with mechanisms to modify and improve such plans. This requires that robots are equipped with some form of high-level reasoning capabilities. Therefore, the proposed learning technique is embedded in a novel distributed control architecture featuring an explicit model of robot's cognitive activity. In particular, cognitive activity is obtained by the interaction of active mental entities, such as intentions, persuasions and expectations. Learning capabilities are implemented starting from the interaction of such mental entities. The proposal is illustrated through an example concerning a robot in charge of reaching a target in an unknown environment cluttered with obstacles

  4. Exploring Representativeness and Informativeness for Active Learning.

    Science.gov (United States)

    Du, Bo; Wang, Zengmao; Zhang, Lefei; Zhang, Liangpei; Liu, Wei; Shen, Jialie; Tao, Dacheng

    2017-01-01

    How can we find a general way to choose the most suitable samples for training a classifier? Even with very limited prior information? Active learning, which can be regarded as an iterative optimization procedure, plays a key role to construct a refined training set to improve the classification performance in a variety of applications, such as text analysis, image recognition, social network modeling, etc. Although combining representativeness and informativeness of samples has been proven promising for active sampling, state-of-the-art methods perform well under certain data structures. Then can we find a way to fuse the two active sampling criteria without any assumption on data? This paper proposes a general active learning framework that effectively fuses the two criteria. Inspired by a two-sample discrepancy problem, triple measures are elaborately designed to guarantee that the query samples not only possess the representativeness of the unlabeled data but also reveal the diversity of the labeled data. Any appropriate similarity measure can be employed to construct the triple measures. Meanwhile, an uncertain measure is leveraged to generate the informativeness criterion, which can be carried out in different ways. Rooted in this framework, a practical active learning algorithm is proposed, which exploits a radial basis function together with the estimated probabilities to construct the triple measures and a modified best-versus-second-best strategy to construct the uncertain measure, respectively. Experimental results on benchmark datasets demonstrate that our algorithm consistently achieves superior performance over the state-of-the-art active learning algorithms.

  5. Fabrication and electrochemical properties of activated CNF/Cu x Mn1- x Fe2O4 composite nanostructures

    Science.gov (United States)

    Nilmoung, Sukanya; Sonsupap, Somchai; Sawangphruk, Montree; Maensiri, Santi

    2018-06-01

    This work reports the fabrication and electrochemical properties of activated carbon nanofibers composited with copper manganese ferrite (ACNF/Cu x Mn1- x Fe2O4: x = 0.0, 0.2, 0.4, 0.6, 0.8) nanostructures. The obtained samples were characterized by means of X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmett-Teller analyzer, thermal gravimetric analysis, X-ray photoemission spectroscopy, and X-ray absorption spectroscopy. The supercapacitive behavior of the electrodes is tested using cyclic voltammetery, galvanostatic charge-discharge and electrochemical impedance spectroscopy. By varying ` x', the highest specific capacitance of 384 F/g at 2 mV/s using CV and 314 F/g at 2 A/g using GCD are obtained for the x = 0.2 electrode. The second one of 235 F/g at 2 mV/s using CV and 172 F/g at 2 A/g using GCD are observed for x = 0.8 electrode. The corresponding energy densities are 74 and 41 Wh/kg, respectively. It is observed that the cyclic stability of the prepared samples strongly depend on the amount of carbon, while the specific capacitance was enhanced by the sample with nearly proportional amount between carbon and CuMnFe2O4. Such results may arise from the synergetic effect between CuMnFe2O4 and ACNF.

  6. From Tootsie Rolls to Composites: Assessing a Spectrum of Active Learning Activities in Engineering Mechanics

    Science.gov (United States)

    2009-05-01

    The introduction of active learning exercises into a traditional lecture has been shown to improve students’ learning. Hands-on learning...opportunities in labs and projects provide are additional tools in the active learning toolbox. This paper presents a series of innovative hands-on active ... learning activities for mechanics of materials topics. These activities are based on a Methodology for Developing Hands-on Active Learning Activities, a

  7. Machine learning of molecular properties: Locality and active learning

    Science.gov (United States)

    Gubaev, Konstantin; Podryabinkin, Evgeny V.; Shapeev, Alexander V.

    2018-06-01

    In recent years, the machine learning techniques have shown great potent1ial in various problems from a multitude of disciplines, including materials design and drug discovery. The high computational speed on the one hand and the accuracy comparable to that of density functional theory on another hand make machine learning algorithms efficient for high-throughput screening through chemical and configurational space. However, the machine learning algorithms available in the literature require large training datasets to reach the chemical accuracy and also show large errors for the so-called outliers—the out-of-sample molecules, not well-represented in the training set. In the present paper, we propose a new machine learning algorithm for predicting molecular properties that addresses these two issues: it is based on a local model of interatomic interactions providing high accuracy when trained on relatively small training sets and an active learning algorithm of optimally choosing the training set that significantly reduces the errors for the outliers. We compare our model to the other state-of-the-art algorithms from the literature on the widely used benchmark tests.

  8. Mind and activity. Psychic mechanism of learning

    Directory of Open Access Journals (Sweden)

    Zoya A. Reshetova

    2017-09-01

    Full Text Available The paper is devoted to the issue of mechanisms of learning for understanding the nature of the human mind. Learning is regarded as a special activity that is important for developing the human mind in a specific cultural and historical setting and indirect activity. The author’s understanding of the ideas developed by the psychological theory of activity for establishing the principles of developing the human mind is highlighted. Interpretation of dialectical connections of brain processes and mind, and also the objective activity that emerges them is provided. According to the activity theory, the causes of the students’ psychological difficulties and the low efficacy of learning within predominant reproductive method or the use of the trial and error method are revealed. Thus, a new understanding of the renowned didactic principles of scientific rigour, accessibility, objectivity, the connection of learning with life and others is offered. The contribution of the psychological theory in organizing and managing the studies, increasing teaching activity and awareness, and the growth of the internal causes of motivation are shown. Particular attention is paid to the issue of intellectual development and creative abilities. The author believes the creative abilities of the student and the way the latter are taught are interconnected. At the same time, the developers and educators should make efforts to develop in the students a systemic orientation in the subject, primarily mastering the method of system analysis. Once the method of system analysis has been mastered, it becomes a general intellectual and developing tool through which activities are organized to solve any teaching problems with whatever type of content and difficulty level. Summing up, the organization and disclosure to the student of the process of learning as an activity with its social, consciously transformative and sense shaping meaning, the conditions of its development

  9. Signs of learning in kinaesthetic science activities

    DEFF Research Database (Denmark)

    Bruun, Jesper; Johannsen, Bjørn Friis

    that students use bodily explorations to construct meaning and understanding from kinaesthetic learning that is relevant to school physics? To answer the question, we employ a semiotics perspective to analyse data from a 1-hour lesson for 8-9th graders which introduced students to kinaesthetic activities, where......?”). The analysis is conducted by searching the data to find episodes that illustrate student activity which can serve as a sign of the object that the ‘experiential gestalt of causation’ is employed in the construction of the intended learning outcome. In essence, we study a chaotic but authentic teaching...

  10. Active learning techniques for librarians practical examples

    CERN Document Server

    Walsh, Andrew

    2010-01-01

    A practical work outlining the theory and practice of using active learning techniques in library settings. It explains the theory of active learning and argues for its importance in our teaching and is illustrated using a large number of examples of techniques that can be easily transferred and used in teaching library and information skills to a range of learners within all library sectors. These practical examples recognise that for most of us involved in teaching library and information skills the one off session is the norm, so we need techniques that allow us to quickly grab and hold our

  11. Astronomy Learning Activities for Tablets

    Science.gov (United States)

    Pilachowski, Catherine A.; Morris, Frank

    2015-08-01

    Four web-based tools allow students to manipulate astronomical data to learn concepts in astronomy. The tools are HTML5, CSS3, Javascript-based applications that provide access to the content on iPad and Android tablets. The first tool “Three Color” allows students to combine monochrome astronomical images taken through different color filters or in different wavelength regions into a single color image. The second tool “Star Clusters” allows students to compare images of stars in clusters with a pre-defined template of colors and sizes in order to produce color-magnitude diagrams to determine cluster ages. The third tool adapts Travis Rector’s “NovaSearch” to allow students to examine images of the central regions of the Andromeda Galaxy to find novae. After students find a nova, they are able to measure the time over which the nova fades away. A fourth tool, Proper Pair, allows students to interact with Hipparcos data to evaluate close double stars are physical binaries or chance superpositions. Further information and access to these web-based tools are available at www.astro.indiana.edu/ala/.

  12. Using Oceanography to Support Active Learning

    Science.gov (United States)

    Byfield, V.

    2012-04-01

    Teachers are always on the lookout for material to give their brightest students, in order to keep them occupied, stimulated and challenged, while the teacher gets on with helping the rest. They are also looking for material that can inspire and enthuse those who think that school is 'just boring!' Oceanography, well presented, has the capacity to do both. As a relatively young science, oceanography is not a core curriculum subject (possibly an advantage), but it draws on the traditional sciences of biology, chemistry, physic and geology, and can provide wonderful examples for teaching concepts in school sciences. It can also give good reasons for learning science, maths and technology. Exciting expeditions (research cruises) to far-flung places; opportunities to explore new worlds, a different angle on topical debates such as climate change, pollution, or conservation can bring a new life to old subjects. Access to 'real' data from satellites or Argo floats can be used to develop analytical and problem solving skills. The challenge is to make all this available in a form that can easily be used by teachers and students to enhance the learning experience. We learn by doing. Active teaching methods require students to develop their own concepts of what they are learning. This stimulates new neural connections in the brain - the physical manifestation of learning. There is a large body of evidence to show that active learning is much better remembered and understood. Active learning develops thinking skills through analysis, problem solving, and evaluation. It helps learners to use their knowledge in realistic and useful ways, and see its importance and relevance. Most importantly, properly used, active learning is fun. This paper presents experiences from a number of education outreach projects that have involved the National Oceanography Centre in Southampton, UK. All contain some element of active learning - from quizzes and puzzles to analysis of real data from

  13. Active Learning in Engineering Education: A (Re)Introduction

    Science.gov (United States)

    Lima, Rui M.; Andersson, Pernille Hammar; Saalman, Elisabeth

    2017-01-01

    The informal network "Active Learning in Engineering Education" (ALE) has been promoting Active Learning since 2001. ALE creates opportunity for practitioners and researchers of engineering education to collaboratively learn how to foster learning of engineering students. The activities in ALE are centred on the vision that learners…

  14. Tracking Active Learning in the Medical School Curriculum: A Learning-Centered Approach

    Science.gov (United States)

    McCoy, Lise; Pettit, Robin K; Kellar, Charlyn; Morgan, Christine

    2018-01-01

    Background: Medical education is moving toward active learning during large group lecture sessions. This study investigated the saturation and breadth of active learning techniques implemented in first year medical school large group sessions. Methods: Data collection involved retrospective curriculum review and semistructured interviews with 20 faculty. The authors piloted a taxonomy of active learning techniques and mapped learning techniques to attributes of learning-centered instruction. Results: Faculty implemented 25 different active learning techniques over the course of 9 first year courses. Of 646 hours of large group instruction, 476 (74%) involved at least 1 active learning component. Conclusions: The frequency and variety of active learning components integrated throughout the year 1 curriculum reflect faculty familiarity with active learning methods and their support of an active learning culture. This project has sparked reflection on teaching practices and facilitated an evolution from teacher-centered to learning-centered instruction. PMID:29707649

  15. Tracking Active Learning in the Medical School Curriculum: A Learning-Centered Approach.

    Science.gov (United States)

    McCoy, Lise; Pettit, Robin K; Kellar, Charlyn; Morgan, Christine

    2018-01-01

    Medical education is moving toward active learning during large group lecture sessions. This study investigated the saturation and breadth of active learning techniques implemented in first year medical school large group sessions. Data collection involved retrospective curriculum review and semistructured interviews with 20 faculty. The authors piloted a taxonomy of active learning techniques and mapped learning techniques to attributes of learning-centered instruction. Faculty implemented 25 different active learning techniques over the course of 9 first year courses. Of 646 hours of large group instruction, 476 (74%) involved at least 1 active learning component. The frequency and variety of active learning components integrated throughout the year 1 curriculum reflect faculty familiarity with active learning methods and their support of an active learning culture. This project has sparked reflection on teaching practices and facilitated an evolution from teacher-centered to learning-centered instruction.

  16. Effect of N+ beam exposure on superoxide dismutase and catalase activities and induction of Mn-SOD in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Song Daojun; Chen Ruolei; Shao Chunlin; Wu Lijun; Yu Zengliang

    2000-01-01

    Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. The superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N + beam exposure was examined. Their activities were increased by N + beam exposure from 8 x 10 14 ions/cm 2 to 6 x 10 15 ions/cm 2 . The treatment of H 2 O 2 and [CHCl 3 + CH 3 CH 2 OH] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of Mn-SOD in D. radiodurans AS1.633 by N + beam exposure. These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidisation

  17. Sequence learning in differentially activated dendrites

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2003-01-01

    . It is proposed that the neural machinery required in such a learning/retrieval mechanism could involve the NMDA receptor, in conjunction with the ability of dendrites to maintain differentially activated regions. In particular, it is suggested that such a parcellation of the dendrite allows the neuron......Differentially activated areas of a dendrite permit the existence of zones with distinct rates of synaptic modification, and such areas can be individually accessed using a reference signal which localizes synaptic plasticity and memory trace retrieval to certain subregions of the dendrite...... to participate in multiple sequences, which can be learned without suffering from the 'wash-out' of synaptic efficacy associated with superimposition of training patterns. This is a biologically plausible solution to the stability-plasticity dilemma of learning in neural networks....

  18. Mn-Ce-V-WOx/TiO2 SCR Catalysts: Catalytic Activity, Stability and Interaction among Catalytic Oxides

    Directory of Open Access Journals (Sweden)

    Xuteng Zhao

    2018-02-01

    Full Text Available A series of Mn-Ce-V-WOx/TiO2 composite oxide catalysts with different molar ratios (active components/TiO2 = 0.1, 0.2, 0.3, 0.6 have been prepared by wet impregnation method and tested in selective catalytic reduction (SCR of NO by NH3 in a wide temperature range. These catalysts were also characterized by X-ray diffraction (XRD, Transmission Electron Microscope (TEM, in situ Fourier Transform infrared spectroscopy (in situ FTIR, H2-Temperature programmed reduction (H2-TPR and X-ray photoelectron spectroscopy (XPS. The results show the catalyst with a molar ratio of active components/TiO2 = 0.2 exhibits highest NO conversion value between 150 °C to 400 °C and good resistance to H2O and SO2 at 250 °C with a gas hourly space velocity (GHSV value of 40,000 h−1. Different oxides are well dispersed and interact with each other. NH3 and NO are strongly adsorbed on the catalyst surface and the adsorption of the reactant gas leads to a redox cycle with the valence state change among the surface oxides. The adsorption of SO2 on Mn4+ and Ce4+ results in good H2O and SO2 resistance of the catalyst, but the effect of Mn and Ce are more than superior water and sulfur resistance. The diversity of valence states of the four active components and their high oxidation-reduction performance are the main reasons for the high NO conversion in this system.

  19. Application of neutron activation analysis to evaluate the health status of equines by means of Cu, Fe, Mn and Zn determinations in their hair

    International Nuclear Information System (INIS)

    Armelin, M.J.A.; Avila, R.L.; Piasentin, R.M.; Saiki, M.

    2001-01-01

    Instrumental neutron activation analysis (INAA) was applied to evaluate the clinical status of equines, belonging to the Military Police of Sao Paulo State, by means of Cu, Fe, Mn and Zn determinations in their hair. Comparison of the results obtained in these analyses with reference values indicated Zn deficiency in the equines, Fe is in the minimum limit and the elements Cu and Mn are within the normal range. (author)

  20. Active Collaborative Learning through Remote Tutoring

    Science.gov (United States)

    Gehret, Austin U.; Elliot, Lisa B.; MacDonald, Jonathan H. C.

    2017-01-01

    An exploratory case study approach was used to describe remote tutoring in biochemistry and general chemistry with students who are deaf or hard of hearing (D/HH). Data collected for analysis were based on the observations of the participant tutor. The research questions guiding this study included (1) How is active learning accomplished in…

  1. Active Learning Strategies in Physics Teaching

    Science.gov (United States)

    Karamustafaoglu, Orhan

    2009-01-01

    The purpose of this study was to determine physics teachers' opinions about student-centered activities applicable in physics teaching and learning in context. A case study approach was used in this research. First, semi-structured interviews were carried out with 6 physics teachers. Then, a questionnaire was developed based on the data obtained…

  2. World War II Memorial Learning Activities.

    Science.gov (United States)

    Tennessee State Dept. of Education, Nashville.

    These learning activities can help students get the most out of a visit to the Tennessee World War II Memorial, a group of ten pylons located in Nashville (Tennessee). Each pylon contains informational text about the events of World War II. The ten pylons are listed as: (1) "Pylon E-1--Terror: America Enters the War against Fascism, June…

  3. Active Learning Strategies for the Mathematics Classroom

    Science.gov (United States)

    Kerrigan, John

    2018-01-01

    Active learning involves students engaging with course content beyond lecture: through writing, applets, simulations, games, and more (Prince, 2004). As mathematics is often viewed as a subject area that is taught using more traditional methods (Goldsmith & Mark, 1999), there are actually many simple ways to make undergraduate mathematics…

  4. Windowed active sampling for reliable neural learning

    NARCIS (Netherlands)

    Barakova, E.I; Spaanenburg, L

    The composition of the example set has a major impact on the quality of neural learning. The popular approach is focused on extensive pre-processing to bridge the representation gap between process measurement and neural presentation. In contrast, windowed active sampling attempts to solve these

  5. Accounting for Sustainability: An Active Learning Assignment

    Science.gov (United States)

    Gusc, Joanna; van Veen-Dirks, Paula

    2017-01-01

    Purpose: Sustainability is one of the newer topics in the accounting courses taught in university teaching programs. The active learning assignment as described in this paper was developed for use in an accounting course in an undergraduate program. The aim was to enhance teaching about sustainability within such a course. The purpose of this…

  6. Single-Atom Mn Active Site in a Triol-Stabilized β-Anderson Manganohexamolybdate for Enhanced Catalytic Activity towards Adipic Acid Production

    Directory of Open Access Journals (Sweden)

    Jianhui Luo

    2018-03-01

    Full Text Available Adipic acid is an important raw chemical for the commercial production of polyamides and polyesters. The traditional industrial adipic acid production utilizes nitric acid to oxidize KA oil (mixtures of cyclohexanone and cyclohexanol, leading to the emission of N2O and thus causing ozone depletion, global warming, and acid rain. Herein, we reported an organically functionalized β-isomer of Anderson polyoxometalates (POMs nanocluster with single-atom Mn, β-{[H3NC(CH2O3]2MnMo6O18}− (1, as a highly active catalyst to selectively catalyze the oxidation of cyclohexanone, cyclohexanol, or KA oil with atom economy use of 30% H2O2 for the eco-friendly synthesis of adipic acid. The catalyst has been characterized by single crystal and powder XRD, XPS, ESI-MS, FT-IR, and NMR. A cyclohexanone (cyclohexanol conversion of >99.9% with an adipic acid selectivity of ~97.1% (~85.3% could be achieved over catalyst 1 with high turnover frequency of 2427.5 h−1 (2132.5 h−1. It has been demonstrated that the existence of Mn3+ atom active site in catalyst 1 and the special butterfly-shaped topology of POMs both play vital roles in the enhancement of catalytic activity.

  7. The double-loop feedback for active learning with understanding

    DEFF Research Database (Denmark)

    Christensen, Hans Peter

    2004-01-01

    Learning is an active process, and in engineering education authentic projects is often used to activate the students and promote learning. However, it is not all activity that leads to deep learning; and in a rapid changing society deep understanding is necessary for life-long learning. Empirical...... findings at DTU question the direct link between high activity and a deep approach to learning. Active learning is important to obtain engineering competencies, but active learning requires more than activity. Feedback and reflection is crucial to the learning process, since new knowledge is built...... on the student’s existing understanding. A model for an active learning process with a double-loop feedback is suggested - the first loop gives the student experience through experimentation, the second conceptual understanding through reflection. Students often miss the second loop, so it is important...

  8. Active learning in optics for girls

    Science.gov (United States)

    Ali, R.; Ashraf, I.

    2017-08-01

    Active learning in Optics (ALO) is a self-funded program under the umbrella of the Abdus Salam International Centre for Theoretical Physics (ICTP) and Quaid-i-Azam University (QAU) to bring physical sciences to traditionally underserved Girls high schools and colleges in Pakistan. There is a significant gender disparity in physical Sciences in Pakistan. In Department of Physics at QAU, approximately 10 to 20% of total students were used to be females from past many decades, but now this percentage is increasing. To keep it up at same pace, we started ALO in January 2016 as a way to provide girls an enriching science experiences, in a very friendly atmosphere. We have organized many one-day activities, to support and encourage girls' students of government high schools and colleges to pursue careers in sciences. In this presentation we will describe our experience and lesson learned in these activities.

  9. Highly efficient alkane oxidation catalyzed by [Mn(V)(N)(CN)4](2-). Evidence for [Mn(VII)(N)(O)(CN)4](2-) as an active intermediate.

    Science.gov (United States)

    Ma, Li; Pan, Yi; Man, Wai-Lun; Kwong, Hoi-Ki; Lam, William W Y; Chen, Gui; Lau, Kai-Chung; Lau, Tai-Chu

    2014-05-28

    The oxidation of various alkanes catalyzed by [Mn(V)(N)(CN)4](2-) using various terminal oxidants at room temperature has been investigated. Excellent yields of alcohols and ketones (>95%) are obtained using H2O2 as oxidant and CF3CH2OH as solvent. Good yields (>80%) are also obtained using (NH4)2[Ce(NO3)6] in CF3CH2OH/H2O. Kinetic isotope effects (KIEs) are determined by using an equimolar mixture of cyclohexane (c-C6H12) and cyclohexane-d12 (c-C6D12) as substrate. The KIEs are 3.1 ± 0.3 and 3.6 ± 0.2 for oxidation by H2O2 and Ce(IV), respectively. On the other hand, the rate constants for the formation of products using c-C6H12 or c-C6D12 as single substrate are the same. These results are consistent with initial rate-limiting formation of an active intermediate between [Mn(N)(CN)4](2-) and H2O2 or Ce(IV), followed by H-atom abstraction from cyclohexane by the active intermediate. When PhCH2C(CH3)2OOH (MPPH) is used as oxidant for the oxidation of c-C6H12, the major products are c-C6H11OH, c-C6H10O, and PhCH2C(CH3)2OH (MPPOH), suggesting heterolytic cleavage of MPPH to generate a Mn═O intermediate. In the reaction of H2O2 with [Mn(N)(CN)4](2-) in CF3CH2OH, a peak at m/z 628.1 was observed in the electrospray ionization mass spectrometry, which is assigned to the solvated manganese nitrido oxo species, (PPh4)[Mn(N)(O)(CN)4](-)·CF3CH2OH. On the basis of the experimental results the proposed mechanism for catalytic alkane oxidation by [Mn(V)(N)(CN)4](2-)/ROOH involves initial rate-limiting O-atom transfer from ROOH to [Mn(N)(CN)4](2-) to generate a manganese(VII) nitrido oxo active species, [Mn(VII)(N)(O)(CN)4](2-), which then oxidizes alkanes (R'H) via a H-atom abstraction/O-rebound mechanism. The proposed mechanism is also supported by density functional theory calculations.

  10. Incorporation of Socio-scientific Content into Active Learning Activities

    Science.gov (United States)

    King, D. B.; Lewis, J. E.; Anderson, K.; Latch, D.; Sutheimer, S.; Webster, G.; Moog, R.

    2014-12-01

    Active learning has gained increasing support as an effective pedagogical technique to improve student learning. One way to promote active learning in the classroom is the use of in-class activities in place of lecturing. As part of an NSF-funded project, a set of in-class activities have been created that use climate change topics to teach chemistry content. These activities use the Process Oriented Guided Inquiry Learning (POGIL) methodology. In this pedagogical approach a set of models and a series of critical thinking questions are used to guide students through the introduction to or application of course content. Students complete the activities in their groups, with the faculty member as a facilitator of learning. Through assigned group roles and intentionally designed activity structure, process skills, such as teamwork, communication, and information processing, are developed during completion of the activity. Each of these climate change activities contains a socio-scientific component, e.g., social, ethical and economic data. In one activity, greenhouse gases are used to explain the concept of dipole moment. Data about natural and anthropogenic production rates, global warming potential and atmospheric lifetimes for a list of greenhouse gases are presented. The students are asked to identify which greenhouse gas they would regulate, with a corresponding explanation for their choice. They are also asked to identify the disadvantages of regulating the gas they chose in the previous question. In another activity, where carbon sequestration is used to demonstrate the utility of a phase diagram, students use economic and environmental data to choose the best location for sequestration. Too often discussions about climate change (both in and outside the classroom) consist of purely emotional responses. These activities force students to use data to support their arguments and hypothesize about what other data could be used in the corresponding discussion to

  11. Fluorescence turn-on detection of alkaline phosphatase activity based on controlled release of PEI-capped Cu nanoclusters from MnO2 nanosheets.

    Science.gov (United States)

    Zhang, Yunyi; Li, Yongxin; Zhang, Cuiyun; Zhang, Qingfeng; Huang, Xinan; Yang, Meiding; Shahzad, Sohail Anjum; Lo, Kenneth Kam-Wing; Yu, Cong; Jiang, Shichun

    2017-08-01

    A fluorescence turn-on assay for alkaline phosphatase (ALP) activity is developed through the controlled release of polyethyleneimine-capped copper nanoclusters (PEI-capped CuNCs) from the MnO 2 nanosheets. In an aqueous solution, the positively charged PEI-capped CuNCs could be adsorbed onto the surface of the negatively charged MnO 2 nanosheets. Such adsorption through favorable electrostatic interactions could efficiently quench the nanocluster fluorescence emission via resonance energy transfer from the PEI-capped CuNCs to the MnO 2 nanosheets. 2-Phospho-L-ascorbic acid (AAP) could be hydrolyzed to L-ascorbic acid (AA) in the presence of ALP. AA could reduce MnO 2 into Mn 2+ and trigger the disintegration of the MnO 2 nanosheets. As a result, the CuNCs were released and the quenched fluorescence was recovered efficiently. The detection strategy is simple, inexpensive, sensitive, selective, with low toxicity, and has better biocompatibility. The newly fabricated biosensor for ALP activity will potentially make it a robust candidate for numerous biological and biomedical applications.

  12. Electrodeposition synthesis of MnO{sub 2}/TiO{sub 2} nanotube arrays nanocomposites and their visible light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xuyao [School of Chemistry Science and Technology, and Institute of Physical Chemistry, Zhanjiang Normal University, Zhanjiang 524048 (China); Zhou, Xiaosong, E-mail: zxs801213@163.com [School of Chemistry Science and Technology, and Institute of Physical Chemistry, Zhanjiang Normal University, Zhanjiang 524048 (China); Li, Xiaoyu, E-mail: lixiaoyu@iga.ac.cn [Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Science, Changchun 130012 (China); Yang, Fei [The State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research of Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing 100101 (China); Jin, Bei; Xu, Tan; Li, Guosheng; Li, Manyi [School of Chemistry Science and Technology, and Institute of Physical Chemistry, Zhanjiang Normal University, Zhanjiang 524048 (China)

    2014-11-15

    Highlights: • MnO{sub 2}/TiO{sub 2} nanotube arrays nanocomposites are prepared by electrodeposition. • MnO{sub 2}/TiO{sub 2} exhibits high visible light photocatalytic activity. • The results of XRD show the depositions are attributed to α-MnO{sub 2}. • A photocatalytic mechanism is discussed under visible light irradiation. - Abstract: MnO{sub 2}/TiO{sub 2} nanotube arrays nanocomposite photocatalysts have been synthesized through an electrodeposition method. X-ray powder diffraction analysis and X-ray photoelectron spectroscopy measurements reveal that the products of electrodeposition method are MnO{sub 2}. Scanning electron microscopy measurements suggest that the depositions are deposited on the surface or internal of the nanotube. UV–vis light absorbance spectra demonstrate the excellent adsorption properties of MnO{sub 2}/TiO{sub 2} over the whole region of visible light, which enables this novel photocatalytic material to possess remarkable activity in the photocatalytic degradation of acid Orange II under visible light radiation. Moreover, a possible photocatalytic mechanism is discussed.

  13. Assessing Student Behaviors and Motivation for Actively Learning Biology

    Science.gov (United States)

    Moore, Michael Edward

    2017-01-01

    Vision and Change states that one of the major changes in the way we design biology courses should be a switch in approach from teacher-centered learning to student-centered learning and identifies active learning as a recommended methods. Studies show performance benefits for students taking courses that use active learning. What is unknown is…

  14. The Validation of the Active Learning in Health Professions Scale

    Science.gov (United States)

    Kammer, Rebecca; Schreiner, Laurie; Kim, Young K.; Denial, Aurora

    2015-01-01

    There is a need for an assessment tool for evaluating the effectiveness of active learning strategies such as problem-based learning in promoting deep learning and clinical reasoning skills within the dual environments of didactic and clinical settings in health professions education. The Active Learning in Health Professions Scale (ALPHS)…

  15. Active Learning Environment with Lenses in Geometric Optics

    Science.gov (United States)

    Tural, Güner

    2015-01-01

    Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

  16. Effect of Mn doped-titania on the activity of metallocene catalyst by in situ ethylene polymerization

    KAUST Repository

    Abdul Kaleel, S. H.

    2012-09-01

    Ethylene polymerization was carried out using highly active metallocene catalysts (Cp 2ZrCl 2 and Cp 2TiCl 2) in combination with methylalumoxane. Titanium(IV) oxide containing 1% Mn as dopant was used as nanofillers. The influence of filler concentration, reaction temperature and pressure on the catalytic activity and polymer properties was investigated. There was a fourfold increase in the activity of zirconocene catalyst by addition of doped-titania. The morphology indicates that the doped-titania nanoparticles have a nucleus effect on the polymerization and caused a homogeneous PE shell around them. The optimum condition for polymerization was found to be 30°C. © 2012 The Korean Society of Industrial and Engineering Chemistry.

  17. 2D/2D nano-hybrids of γ-MnO{sub 2} on reduced graphene oxide for catalytic ozonation and coupling peroxymonosulfate activation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuxian [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing Engineering Research Center of Process Pollution Control, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); Xie, Yongbing, E-mail: ybxie@ipe.ac.cn [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing Engineering Research Center of Process Pollution Control, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Sun, Hongqi [Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); Xiao, Jiadong; Cao, Hongbin [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing Engineering Research Center of Process Pollution Control, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Shaobin, E-mail: shaobin.wang@curtin.edu.au [Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia)

    2016-01-15

    Highlights: • 2D γ-MnO{sub 2}/2D rGO hybrids (MnO{sub 2}/rGO) via a facile hydrothermal route were prepared. • MnO{sub 2}/rGO exhibits high activity in catalytic ozonation of 4-nitrophenol. • ·O{sub 2}{sup ̄} and {sup 1}O{sub 2} are the major radicals for 4-nitrophenol degradation and mineralization. • A synergistic effect of ozonation and peroxymonosulfate oxidation was evaluated. - Abstract: Two-dimensional reduced graphene oxide (2D rGO) was employed as both a shape-directing medium and support to fabricate 2D γ-MnO{sub 2}/2D rGO nano-hybrids (MnO{sub 2}/rGO) via a facile hydrothermal route. For the first time, the 2D/2D hybrid materials were used for catalytic ozonation of 4-nitrophenol. The catalytic efficiency of MnO{sub 2}/rGO was much higher than either MnO{sub 2} or rGO only, and rGO was suggested to play the role for promoting electron transfers. Quenching tests using tert-butanol, p-benzoquinone, and sodium azide suggested that the major radicals responsible for 4-nitrophenol degradation and mineralization are O{sub 2}{sup ̄} and {sup 1}O{sub 2}, but not ·OH. Reusability tests demonstrated a high stability of the materials in catalytic ozonation with minor Mn leaching below 0.5 ppm. Degradation mechanism, reaction kinetics, reusability and a synergistic effect between catalytic ozonation and coupling peroxymonosulfate (PMS) activation were also discussed.

  18. Microprobe analysis, iono- and photo-luminescence of Mn2+ activated ZnGa2O4 fibres

    International Nuclear Information System (INIS)

    Santos, N.F.; Fernandes, A.J.S.; Alves, L.C.; Sobolev, N.A.; Alves, E.; Lorenz, K.; Costa, F.M.; Monteiro, T.

    2013-01-01

    Cubic ZnGa 2 O 4 fibres have been grown by the laser floating zone technique with different pulling rates. In fibres activated with manganese ions, the room temperature photo- and iono-luminescence is dominated by an intense green emission which is observed by the naked eye. The green band is due to an overlap of the 4 T 1 → 6 A 1 intraionic transitions of the Mn 2+ ions in different sites in the gallate host. The fibres’ photoluminescence spectra have been found to be dependent on the excitation energy. Additionally, the intensity of the green photo- and iono-luminescence is strongly sensitive to the measurement temperature and proton irradiation time. Micro PIXE analysis was used in order to verify the homogeneous distribution of the Mn luminescence activators and determine its concentration as well as for verification of impurity contents that may have been incorporated during the fibres growth. The potential of ionoluminescence measurements for characterization of optical materials is discussed

  19. Antifungal activity of wide band gap Thioglycolic acid capped ZnS:Mn semiconductor nanoparticles against some pathogenic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Isam M.; Ali, Iftikhar M. [Department of physics, College of Science, Baghdad University, Baghdad (Iraq); Dheeb, Batol Imran [Department of Biology, College of Education, Iraqia University, Baghdad (Iraq); Abas, Qayes A. [Department of physics, College of Education, University of Anbar, Anbar (Iraq); Asmeit Ramizy, E-mail: asmat_hadithi@yahoo.com [Department of physics, College of Science, University of Anbar, Anbar (Iraq); Renewable energy Research Center, University of Anbar, Anbar (Iraq); Eisa, M.H. [Department of physics, College of Science, Sudan University of Science Technology, Khartoum 11113 (Sudan); Department of physics, College of Science, Al Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623 (Saudi Arabia); Aljameel, A.I. [Department of physics, College of Science, Al Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623 (Saudi Arabia)

    2017-04-01

    The manganese doped zinc sulfide nanoparticles were synthesized by simple aqueous chemical reaction of manganese chloride, zinc acetate and thioacitamide in aqueous solution. Thioglycolic acid is used as capping agent for controlling the nanoparticle size. The main advantage of the ZnS:Mn nanoparticles of diameter ~ 2.73 nm is that the sample is prepared by using non-toxic precursors in a cost effective and eco-friendly way. The structural, morphological and chemical composition of the nanoparticles have been investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with energy dispersion spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. The nanosize of the prepared nanoparticles was elucidated by Scanning Electron Microscopy (SEM). FTIR result ensures that Thioglycolic acid is well bonded on the surface of ZnS:Mn NPs. The antifungal effects of Thioglycolic acid capped ZnS:Mn nanoparticles exhibited a potent antifungal activity against tested fungal strains, so deserving further investigation for clinical applications. The antifungal property of manganese doped zinc sulphide nanoparticles is attributed to the generation of reactive oxygen species due to the interaction of nanoparticles with water. Additionally, the presence of Zn and S in the zone of inhibition area leads to perturbation of fungi cell membranes resulting in growth inhibition. - Highlights: • The manganese doped zinc sulfide nanoparticles were synthesized. • Thioglycolic acid is used as capping agent for controlling the nanoparticle size. • The structural, morphological and chemical composition of the nanoparticles has been investigated. • The presence of Zn and S in the zone of inhibition area leads to perturbation of fungi cell membranes.

  20. Antifungal activity of wide band gap Thioglycolic acid capped ZnS:Mn semiconductor nanoparticles against some pathogenic fungi

    International Nuclear Information System (INIS)

    Ibrahim, Isam M.; Ali, Iftikhar M.; Dheeb, Batol Imran; Abas, Qayes A.; Asmeit Ramizy; Eisa, M.H.; Aljameel, A.I.

    2017-01-01

    The manganese doped zinc sulfide nanoparticles were synthesized by simple aqueous chemical reaction of manganese chloride, zinc acetate and thioacitamide in aqueous solution. Thioglycolic acid is used as capping agent for controlling the nanoparticle size. The main advantage of the ZnS:Mn nanoparticles of diameter ~ 2.73 nm is that the sample is prepared by using non-toxic precursors in a cost effective and eco-friendly way. The structural, morphological and chemical composition of the nanoparticles have been investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with energy dispersion spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. The nanosize of the prepared nanoparticles was elucidated by Scanning Electron Microscopy (SEM). FTIR result ensures that Thioglycolic acid is well bonded on the surface of ZnS:Mn NPs. The antifungal effects of Thioglycolic acid capped ZnS:Mn nanoparticles exhibited a potent antifungal activity against tested fungal strains, so deserving further investigation for clinical applications. The antifungal property of manganese doped zinc sulphide nanoparticles is attributed to the generation of reactive oxygen species due to the interaction of nanoparticles with water. Additionally, the presence of Zn and S in the zone of inhibition area leads to perturbation of fungi cell membranes resulting in growth inhibition. - Highlights: • The manganese doped zinc sulfide nanoparticles were synthesized. • Thioglycolic acid is used as capping agent for controlling the nanoparticle size. • The structural, morphological and chemical composition of the nanoparticles has been investigated. • The presence of Zn and S in the zone of inhibition area leads to perturbation of fungi cell membranes.

  1. Three-dimensional MnO{sub 2} porous hollow microspheres for enhanced activity as ozonation catalysts in degradation of bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiuqin; Wan, Yifeng; Huang, Yajing [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); He, Chun, E-mail: hechun@mail.sysu.edu.cn [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275 (China); Zhang, Zaili; He, Zhuoyan; Hu, Lingling; Zeng, Jiawei [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Shu, Dong, E-mail: dshu@scnu.edu.cn [Key Lab of Technology on Electrochemical Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou, 510006 (China)

    2017-01-05

    Highlights: • 3D MnO{sub 2} porous hollow microspheres (PHMSs) are prepared by a self-template process. • MnO{sub 2} PHMSs with excellent adsorption and catalytic ozonation performance for BPA. • MnO{sub 2} PHMSs show enhanced activity due to hollow-mesoporous shell spherical structure. • O{sub 2}{sup −} and ·OH are reactive species to induce effective catalytic ozonation of BPA. - Abstract: Three-dimensional (3D) MnO{sub 2} porous hollow microspheres (δ- and α- MnO{sub 2} PHMSs), with high adsorption and catalytic ozonation performance, were synthesized by a self-template (MnCO{sub 3} microspheres) process at room temperature. The synthesized MnO{sub 2} PHMSs were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area. The results showed that PHMSs exhibit the excellent adsorption ability and catalytic activity owning to their hollow spherical structure, mesoporous shell and well-defined interior voids, leading to the strong adsorption for bisphenol A (BPA) and the retention of O{sub 3} molecules on catalyst. Moreover, the catalytic performance of α-MnO{sub 2} PHMSs was better than that of δ-MnO{sub 2} PHMSs which was attributed to the richer lattice oxygen of α-MnO{sub 2} PHMSs to accelerate O{sub 3} decomposition by producing more reactive oxidative species. The degradation efficiency of BPA using 3D α-MnO{sub 2} PHMSs was more than 90% in the presence of ozone within 30 min reaction time. The probe tests for reactive oxidative species (ROSs) displayed that BPA degradation by catalytic ozonation is dominated by ·O{sub 2}{sup −} and ·OH in our present study. Furthermore, the organic compounds as intermediates of the degradation process were identified by LC/MS.

  2. Active Learning in Engineering Education: a (re)introduction

    DEFF Research Database (Denmark)

    Lima, Rui M.; Andersson, Pernille Hammar; Saalman, Elisabeth

    2017-01-01

    The informal network ‘Active Learning in Engineering Education’ (ALE) has been promoting Active Learning since 2001. ALE creates opportunity for practitioners and researchers of engineering education to collaboratively learn how to foster learning of engineering students. The activities in ALE...... were reviewed by the European Journal of Engineering Education community and this theme issue ended up with eight contributions, which are different both in their research and Active Learning approaches. These different Active Learning approaches are aligned with the different approaches that can...

  3. Mn bioavailability by polarized Caco-2 cells: comparison between Mn gluconate and Mn oxyprolinate

    Directory of Open Access Journals (Sweden)

    Fulgenzi Alessandro

    2011-07-01

    Full Text Available Abstract Background Micronutrient inadequate intake is responsible of pathological deficiencies and there is a need of assessing the effectiveness of metal supplementation, frequently proposed to rebalance poor diets. Manganese (Mn is present in many enzymatic intracellular systems crucial for the regulation of cell metabolism, and is contained in commercially available metal supplements. Methods We compared the effects of two different commercial Mn forms, gluconate (MnGluc and oxyprolinate (MnOxP. For this purpose we used the polarized Caco-2 cells cultured on transwell filters, an established in vitro model of intestinal epithelium. Since micronutrient deficiency may accelerate mitochondrial efficiency, the mitochondrial response of these cells, in the presence of MnGluc and MnOxP, by microscopy methods and by ATP luminescence assay was used. Results In the presence of both MnOxP and MnGluc a sustained mitochondrial activity was shown by mitoTraker labeling (indicative of mitochondrial respiration, but ATP intracellular content remained comparable to untreated cells only in the presence of MnOxP. In addition MnOxP transiently up-regulated the antioxidant enzyme Mn superoxide dismutase more efficiently than MnGluc. Both metal treatments preserved NADH and βNADPH diaphorase oxidative activity, avoided mitochondrial dysfunction, as assessed by the absence of a sustained phosphoERK activation, and were able to maintain cell viability. Conclusions Collectively, our data indicate that MnOxP and MnGluc, and primarily the former, produce a moderate and safe modification of Caco-2 cell metabolism, by activating positive enzymatic mechanisms, thus could contribute to long-term maintenance of cell homeostasis.

  4. LaMn1-xFe xO3 and LaMn0.1-xFe0.90Mo x O3 perovskites: synthesis, characterization and catalytic activity in H2O2 reactions

    Directory of Open Access Journals (Sweden)

    Fabiano Magalhães

    2008-09-01

    Full Text Available In this work two perovskites were prepared: LaMn1-xFe xO3, and LaMn0.1-x Fe0.90Mo xO3. XRD and Mössbauer spectroscopy suggest the formation of pure phase perovskite with the incorporation of Fe and Mo in the structure. The catalytic activity of these materials was studied in two reactions with H2O2: the decomposition to O2, and the oxidation of the model organic contaminant methylene blue. The perovskite composition strongly affects the catalytic activity, while Fe decreases the H2O2 decomposition Mo strongly improves dye oxidation.

  5. Permanganate/bisulfite (PM/BS) conditioning-horizontal electro-dewatering (HED) of activated sludge: Effect of reactive Mn(III) species.

    Science.gov (United States)

    Guo, Xinxin; Wang, Yili; Wang, Dongsheng

    2017-11-01

    A novel activated sludge (AS) conditioning method through permanganate/bisulfate (PM/BS) process was proposed. The method involved a new conditioner of reactive Mn(III) intermediate. Moreover, a Mn(III) conditioning-horizontal electro-dewatering (Mn(III) C-HED) process was established to improve AS dewatering performance. Underlying mechanisms were unraveled by investigating changes in physicochemical characteristics, scanning electron microscope (SEM) morphology, and transformation of water and organic matters. The optimum dewatering conditions for Mn(III) C-HED process with the final water content of 86.94% were determined as the combination of KMnO 4 0.01 mol/L AS and NaHSO 3 0.05 mol/L AS at 20 V for 120 min. Results showed that Mn(III) C-HED process effectively reduced free water and bound water with the corresponding removal ratios of 51.68% and 87.62% at the anode-side as well as 36.55% and 85.08% at the cathode-side, respectively. During the PM/BS process, the produced Mn(III), Mn 2+ , and MnO 2 exerted chemical and physical effects on AS conditioning and dewatering. Mn(III) disintegrated extracellular polymeric substances (EPS) fractions and cells in AS, as well as induced partial bound water release. Additionally, flocculation effect induced by Mn 2+ and MnO 2 skeleton building also benefited AS dewatering. AS cells were further disrupted under the effect of a horizontal electric field. Accordingly, EPS within the AS matrix was solubilized, tightly bound (TB)-EPS or loosely bound (LB)-EPS was converted to their corresponding outer EPS fractions, and AS dewaterability improved. Additionally, changes in pH and temperature at HED stage damaged the AS cells and changed the floc properties, thereby leading to easy separation of liquid and AS particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Changing University Students' Alternative Conceptions of Optics by Active Learning

    Science.gov (United States)

    Hadžibegovic, Zalkida; Sliško, Josip

    2013-01-01

    Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the…

  7. Faculty motivations to use active learning among pharmacy educators.

    Science.gov (United States)

    Rockich-Winston, Nicole; Train, Brian C; Rudolph, Michael J; Gillette, Chris

    2018-03-01

    Faculty motivations to use active learning have been limited to surveys evaluating faculty perceptions within active learning studies. Our objective in this study was to evaluate the relationship between faculty intrinsic motivation, extrinsic motivation, and demographic variables and the extent of active learning use in the classroom. An online survey was administered to individual faculty members at 137 colleges and schools of pharmacy across the United States. The survey assessed intrinsic and extrinsic motivations, active learning strategies, classroom time dedicated to active learning, and faculty development resources. Bivariate associations and multivariable stepwise linear regression were used to analyze the results. In total, 979 faculty members completed the questionnaire (23.6% response rate). All motivation variables were significantly correlated with percent active learning use (p active learning methods used in the last year (r = 0.259, p active learning use. Our results suggest that faculty members who are intrinsically motivated to use active learning are more likely to dedicate additional class time to active learning. Furthermore, intrinsic motivation may be positively associated with encouraging faculty members to attend active learning workshops and supporting faculty to use various active learning strategies in the classroom. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Active Learning: The Importance of Developing a Comprehensive Measure

    Science.gov (United States)

    Carr, Rodney; Palmer, Stuart; Hagel, Pauline

    2015-01-01

    This article reports on an investigation into the validity of a widely used scale for measuring the extent to which higher education students employ active learning strategies. The scale is the active learning scale in the Australasian Survey of Student Engagement. This scale is based on the Active and Collaborative Learning scale of the National…

  9. Active Learning in ASTR 101 Lectures

    Science.gov (United States)

    Deming, Grace L.

    1998-12-01

    The lecture is the most common teaching method used at colleges and universities, but does this format facilitate student learning? Lectures can be brilliantly delivered, but they are received by a passive audience. As time passes during a lecture, student attention and effective notetaking diminish. Many students become more interested in a subject and retain information longer in courses that rely on active rather than passive teaching methods. Interactive teaching strategies such as the think-pair-share-(write), the 3-minute paper, and the misconception confrontation can be used to actively engage students during lecture. As a cooperative learning strategy, the think-pair-share-(write) technique requires active discussion by everyone in the class. The "write" component structures individual accountability into the activity. The 3-minute paper is an expansion of the standard 1-minute paper feedback technique, but is required of all students rather than voluntary or anonymous. The misconception confrontation technique allows students to focus on how their pre- conceived notions differ from the scientific explanation. These techniques can be easily adopted by anyone currently using a standard lecture format for introductory astronomy. The necessary components are a commitment by the instructor to require active participation by all students and a willingness to try new teaching methods.

  10. Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hong In [Kyungpook National University, Daegu (Korea, Republic of); Moon, Do Hyun [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Lah, Myoung Soo [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2010-11-15

    New complex [Mn(II)H{sub 1.5}L]{sub 2}[Mn(II)H{sub 3}L]{sub 2}(ClO{sub 4}){sub 5}·3H{sub 2}O, where H{sub 3}L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H{sub 1.5}L]{sup 0.5+} complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H{sub 3}L]{sup 2+} complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)- 6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS{sup +·} was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

  11. Active Learning in the Era of Big Data

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Davis, IV, Warren L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    Active learning methods automatically adapt data collection by selecting the most informative samples in order to accelerate machine learning. Because of this, real-world testing and comparing active learning algorithms requires collecting new datasets (adaptively), rather than simply applying algorithms to benchmark datasets, as is the norm in (passive) machine learning research. To facilitate the development, testing and deployment of active learning for real applications, we have built an open-source software system for large-scale active learning research and experimentation. The system, called NEXT, provides a unique platform for realworld, reproducible active learning research. This paper details the challenges of building the system and demonstrates its capabilities with several experiments. The results show how experimentation can help expose strengths and weaknesses of active learning algorithms, in sometimes unexpected and enlightening ways.

  12. Understanding Fatty Acid Metabolism through an Active Learning Approach

    Science.gov (United States)

    Fardilha, M.; Schrader, M.; da Cruz e Silva, O. A. B.; da Cruz e Silva, E. F.

    2010-01-01

    A multi-method active learning approach (MALA) was implemented in the Medical Biochemistry teaching unit of the Biomedical Sciences degree at the University of Aveiro, using problem-based learning as the main learning approach. In this type of learning strategy, students are involved beyond the mere exercise of being taught by listening. Less…

  13. Persulfate activation by iron oxide-immobilized MnO2 composite: identification of iron oxide and the optimum pH for degradations.

    Science.gov (United States)

    Jo, Young-Hoon; Do, Si-Hyun; Kong, Sung-Ho

    2014-01-01

    Iron oxide-immobilized manganese oxide (MnO2) composite was prepared and the reactivity of persulfate (PS) with the composite as activator was investigated for degradation of carbon tetrachloride and benzene at various pH levels. Brunauer-Emmett-Teller (BET) surface area of the composite was similar to that of pure MnO2 while the pore volume and diameter of composite was larger than those of MnO2. Scanning electron microscopy couples with energy dispersive spectroscopy (SEM-EDS) showed that Fe and Mn were detected on the surface of the composite, and X-ray diffraction (XRD) analysis indicated the possibilities of the existence of various iron oxides on the composite surface. Furthermore, the analyses of X-ray photoelectron (XPS) spectra revealed that the oxidation state of iron was identified as 1.74. In PS/composite system, the same pH for the highest degradation rates of both carbon tetrachloride and benzene were observed and the value of pH was 9. Scavenger test was suggested that both oxidants (i.e. hydroxyl radical, sulfate radical) and reductant (i.e. superoxide anion) were effectively produced when PS was activated with the iron-immobilized MnO2. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Active Learning Increases Children's Physical Activity across Demographic Subgroups.

    Science.gov (United States)

    Bartholomew, John B; Jowers, Esbelle M; Roberts, Gregory; Fall, Anna-Mária; Errisuriz, Vanessa L; Vaughn, Sharon

    2018-01-01

    Given the need to find more opportunities for physical activity within the elementary school day, this study was designed to asses the impact of I-CAN!, active lessons on: 1) student physical activity (PA) outcomes via accelerometry; and 2) socioeconomic status (SES), race, sex, body mass index (BMI), or fitness as moderators of this impact. Participants were 2,493 fourth grade students (45.9% male, 45.8% white, 21.7% low SES) from 28 central Texas elementary schools randomly assigned to intervention (n=19) or control (n=9). Multilevel regression models evaluated the effect of I-CAN! on PA and effect sizes were calculated. The moderating effects of SES, race, sex, BMI, and fitness were examined in separate models. Students in treatment schools took significantly more steps than those in control schools (β = 125.267, SE = 41.327, p = .002, d = .44). I-CAN! had a significant effect on MVPA with treatment schools realizing 80% (β = 0.796, SE =0.251, p = .001; d = .38) more MVPA than the control schools. There were no significant school-level differences on sedentary behavior (β = -0.177, SE = 0.824, p = .83). SES, race, sex, BMI, and fitness level did not moderate the impact of active learning on step count and MVPA. Active learning increases PA within elementary students, and does so consistently across demographic sub-groups. This is important as these sub-groups represent harder to reach populations for PA interventions. While these lessons may not be enough to help children reach daily recommendations of PA, they can supplement other opportunities for PA. This speaks to the potential of schools to adopt policy change to require active learning.

  15. The ICAP Active Learning Framework Predicts the Learning Gains Observed in Intensely Active Classroom Experiences

    Directory of Open Access Journals (Sweden)

    Benjamin L. Wiggins

    2017-05-01

    Full Text Available STEM classrooms (science, technology, engineering, and mathematics in postsecondary education are rapidly improved by the proper use of active learning techniques. These techniques occupy a descriptive spectrum that transcends passive teaching toward active, constructive, and, finally, interactive methods. While aspects of this framework have been examined, no large-scale or actual classroom-based data exist to inform postsecondary education STEM instructors about possible learning gains. We describe the results of a quasi-experimental study to test the apex of the ICAP framework (interactive, constructive, active, and passive in this ecological classroom environment. Students in interactive classrooms demonstrate significantly improved learning outcomes relative to students in constructive classrooms. This improvement in learning is relatively subtle; similar experimental designs without repeated measures would be unlikely to have the power to observe this significance. We discuss the importance of seemingly small learning gains that might propagate throughout a course or departmental curriculum, as well as improvements with the necessity for faculty to develop and implement similar activities.

  16. Determination of Au, Sb, As, Br, Na, K, Cd, Mn and Cl in rice from Vietnam by neutron activation analysis

    International Nuclear Information System (INIS)

    Tran Van, L.; Teherani, D.K.

    1988-01-01

    Gold, antimony, arsenic, bromine, sodium, potassium, cadmium, manganese and chlorine were determined by neutron activation analysis in various rice seed, brand layer and husk samples from Vietnam. The following concentration values were found: Au 0.05-0.28 ppm, Sb 0.05-1.08 ppm, As 0.08-0.94 ppm, Br 0.82-6.72 ppm, Na 16.71-25.71 ppm, K 2582-5163 ppm, Mn 19.26-33.43 ppm, Cd 0.51-2.42 ppm and Cl 205.20-828.61 ppm in rice seed. Statistically significant differences in Au, Sb, Cd contents were detected in rice seed and husk, as well as brand layer and husk. (author) 8 refs.; 3 figs

  17. AMP-activated protein kinase controls exercise training- and AICAR-induced increases in SIRT3 and MnSOD

    DEFF Research Database (Denmark)

    Brandauer, Josef; Andersen, Marianne A; Kellezi, Holti

    2015-01-01

    , the acetylation status of SIRT3 target lysine residues on MnSOD (K122) or oligomycin-sensitivity conferring protein (OSCP; K139) was not altered in either mouse or human skeletal muscle in response to acute exercise. We propose an important role for AMPK in regulating mitochondrial function and ROS handling......The mitochondrial protein deacetylase sirtuin (SIRT) 3 may mediate exercise training-induced increases in mitochondrial biogenesis and improvements in reactive oxygen species (ROS) handling. We determined the requirement of AMP-activated protein kinase (AMPK) for exercise training-induced increases...... in skeletal muscle abundance of SIRT3 and other mitochondrial proteins. Exercise training for 6.5 weeks increased SIRT3 (p

  18. Determination of Na, Mn and Cu in cocoon, raw silk and degummed silk by nondestructive activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Y; Ishiguro, Y [Industrial Research Inst. of Kanagawa Prefecture, Yokohama (Japan)

    1976-01-01

    The sodium, manganese and copper contained in cocoons, raw silk and degummed silk thread were determined by the nondestructive activation analysis. After each sample was irradiated with the thermal neutron flux of 5 x 10/sup 11/n/cm/sup 2/.sec, its ..gamma..-ray spectrum was measured with a NaI(Tl) detector. With the photoelectric peaks at 511 keV (/sup 64/Cu), 1368 keV (/sup 24/Na) and 847 keV (/sup 56/Mn), each element was quantitatively determined and its content was obtained. The measurement of the ..gamma..-ray spectra of samples with a Ge (Li) detector proved the presence of An, Sb, Fe, Zn, Cr, Sc, Co, etc. Large amounts of Na and Cu were detected in the sericin portion of cocoons, and the adhesion of Cu from a reeling-off machine to raw silk was also observed during the process of degumming cocoons to make raw silk.

  19. Face-to-Face Activities in Blended Learning

    DEFF Research Database (Denmark)

    Kjærgaard, Annemette

    While blended learning combines online and face-to-face teaching, research on blended learning has primarily focused on the role of technology and the opportunities it creates for engaging students. Less focus has been put on face-to-face activities in blended learning. This paper argues...... that it is not only the online activities in blended learning that provide new opportunities for rethinking pedagogy in higher education, it is also imperative to reconsider the face-to-face activities when part of the learning is provided online. Based on a review of blended learning in business and management...... education, we identify what forms of teaching and learning are suggested to take place face-to-face when other activities are moved online. We draw from the Community of Inquiry framework to analyze how face-to-face activities contribute to a blended learning pedagogy and discuss the implications...

  20. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Ok Hee [YongIn University, Yongin (Korea, Republic of)

    2008-10-15

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized.

  1. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam; Lee, Ok Hee

    2008-01-01

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized

  2. Active Metric Learning from Relative Comparisons

    OpenAIRE

    Xiong, Sicheng; Rosales, Rómer; Pei, Yuanli; Fern, Xiaoli Z.

    2014-01-01

    This work focuses on active learning of distance metrics from relative comparison information. A relative comparison specifies, for a data point triplet $(x_i,x_j,x_k)$, that instance $x_i$ is more similar to $x_j$ than to $x_k$. Such constraints, when available, have been shown to be useful toward defining appropriate distance metrics. In real-world applications, acquiring constraints often require considerable human effort. This motivates us to study how to select and query the most useful ...

  3. Active Discriminative Dictionary Learning for Weather Recognition

    Directory of Open Access Journals (Sweden)

    Caixia Zheng

    2016-01-01

    Full Text Available Weather recognition based on outdoor images is a brand-new and challenging subject, which is widely required in many fields. This paper presents a novel framework for recognizing different weather conditions. Compared with other algorithms, the proposed method possesses the following advantages. Firstly, our method extracts both visual appearance features of the sky region and physical characteristics features of the nonsky region in images. Thus, the extracted features are more comprehensive than some of the existing methods in which only the features of sky region are considered. Secondly, unlike other methods which used the traditional classifiers (e.g., SVM and K-NN, we use discriminative dictionary learning as the classification model for weather, which could address the limitations of previous works. Moreover, the active learning procedure is introduced into dictionary learning to avoid requiring a large number of labeled samples to train the classification model for achieving good performance of weather recognition. Experiments and comparisons are performed on two datasets to verify the effectiveness of the proposed method.

  4. Strategies for active learning in online continuing education.

    Science.gov (United States)

    Phillips, Janet M

    2005-01-01

    Online continuing education and staff development is on the rise as the benefits of access, convenience, and quality learning are continuing to take shape. Strategies to enhance learning call for learner participation that is self-directed and independent, thus changing the educator's role from expert to coach and facilitator. Good planning of active learning strategies promotes optimal learning whether the learning content is presented in a course or a just-in-time short module. Active learning strategies can be used to enhance online learning during all phases of the teaching-learning process and can accommodate a variety of learning styles. Feedback from peers, educators, and technology greatly influences learner satisfaction and must be harnessed to provide effective learning experiences. Outcomes of active learning can be assessed online and implemented conveniently and successfully from the initiation of the course or module planning to the end of the evaluation process. Online learning has become accessible and convenient and allows the educator to track learner participation. The future of online education will continue to grow, and using active learning strategies will ensure that quality learning will occur, appealing to a wide variety of learning needs.

  5. Active Learning Not Associated with Student Learning in a Random Sample of College Biology Courses

    Science.gov (United States)

    Andrews, T. M.; Leonard, M. J.; Colgrove, C. A.; Kalinowski, S. T.

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning. PMID:22135373

  6. STEM learning activity among home-educating families

    Science.gov (United States)

    Bachman, Jennifer

    2011-12-01

    Science, technology, engineering, and mathematics (STEM) learning was studied among families in a group of home-educators in the Pacific Northwest. Ethnographic methods recorded learning activity (video, audio, fieldnotes, and artifacts) which was analyzed using a unique combination of Cultural-Historical Activity Theory (CHAT) and Mediated Action (MA), enabling analysis of activity at multiple levels. Findings indicate that STEM learning activity is family-led, guided by parents' values and goals for learning, and negotiated with children to account for learner interests and differences, and available resources. Families' STEM education practice is dynamic, evolves, and influenced by larger societal STEM learning activity. Parents actively seek support and resources for STEM learning within their home-school community, working individually and collectively to share their funds of knowledge. Home-schoolers also access a wide variety of free-choice learning resources: web-based materials, museums, libraries, and community education opportunities (e.g. afterschool, weekend and summer programs, science clubs and classes, etc.). A lesson-heuristic, grounded in Mediated Action, represents and analyzes home STEM learning activity in terms of tensions between parental goals, roles, and lesson structure. One tension observed was between 'academic' goals or school-like activity and 'lifelong' goals or everyday learning activity. Theoretical and experiential learning was found in both activity, though parents with academic goals tended to focus more on theoretical learning and those with lifelong learning goals tended to be more experiential. Examples of the National Research Council's science learning strands (NRC, 2009) were observed in the STEM practices of all these families. Findings contribute to the small but growing body of empirical CHAT research in science education, specifically to the empirical base of family STEM learning practices at home. It also fills a

  7. Enhancing Learning Outcomes through Application Driven Activities in Marketing

    Science.gov (United States)

    Stegemann, Nicole; Sutton-Brady, Catherine

    2013-01-01

    This paper introduces an activity used in class to allow students to apply previously acquired information to a hands-on task. As the authors have previously shown active learning is a way to effectively facilitate and improve students' learning outcomes. As a result to improve learning outcomes we have overtime developed a series of learning…

  8. Improving active Mealy machine learning for protocol conformance testing

    NARCIS (Netherlands)

    Aarts, F.; Kuppens, H.; Tretmans, J.; Vaandrager, F.; Verwer, S.

    2014-01-01

    Using a well-known industrial case study from the verification literature, the bounded retransmission protocol, we show how active learning can be used to establish the correctness of protocol implementation I relative to a given reference implementation R. Using active learning, we learn a model M

  9. Opportunities to Create Active Learning Techniques in the Classroom

    Science.gov (United States)

    Camacho, Danielle J.; Legare, Jill M.

    2015-01-01

    The purpose of this article is to contribute to the growing body of research that focuses on active learning techniques. Active learning techniques require students to consider a given set of information, analyze, process, and prepare to restate what has been learned--all strategies are confirmed to improve higher order thinking skills. Active…

  10. Telling Active Learning Pedagogies Apart: From Theory to Practice

    Science.gov (United States)

    Cattaneo, Kelsey Hood

    2017-01-01

    Designing learning environments to incorporate active learning pedagogies is difficult as definitions are often contested and intertwined. This article seeks to determine whether classification of active learning pedagogies (i.e., project-based, problem-based, inquiry-based, case-based, and discovery-based), through theoretical and practical…

  11. Effects of Sharing Clickers in an Active Learning Environment

    Science.gov (United States)

    Daniel, Todd; Tivener, Kristin

    2016-01-01

    Scientific research into learning enhancement gained by the use of clickers in active classrooms has largely focused on the use of individual clickers. In this study, we compared the learning experiences of participants in active learning groups in which an entire small group shared a single clicker to groups in which each member of the group had…

  12. Are students' impressions of improved learning through active learning methods reflected by improved test scores?

    Science.gov (United States)

    Everly, Marcee C

    2013-02-01

    To report the transformation from lecture to more active learning methods in a maternity nursing course and to evaluate whether student perception of improved learning through active-learning methods is supported by improved test scores. The process of transforming a course into an active-learning model of teaching is described. A voluntary mid-semester survey for student acceptance of the new teaching method was conducted. Course examination results, from both a standardized exam and a cumulative final exam, among students who received lecture in the classroom and students who had active learning activities in the classroom were compared. Active learning activities were very acceptable to students. The majority of students reported learning more from having active-learning activities in the classroom rather than lecture-only and this belief was supported by improved test scores. Students who had active learning activities in the classroom scored significantly higher on a standardized assessment test than students who received lecture only. The findings support the use of student reflection to evaluate the effectiveness of active-learning methods and help validate the use of student reflection of improved learning in other research projects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Synthesis of Mn-intercalated layered titanate by exfoliation–flocculation approach and its efficient photocatalytic activity under visible–light

    International Nuclear Information System (INIS)

    Fu, Jie; Tian, Yanlong; Chang, Binbin; Li, Gengnan; Xi, Fengna; Dong, Xiaoping

    2012-01-01

    A novel Mn-intercalated layered titanate as highly active photocatalyst in visible-light region has been synthesized via a convenient and efficient exfoliation–flocculation approach with divalent Mn ions and monolayer titanate nanosheets. The 0.91 nm interlayer spacing of obtained photocatalyst is in accordance with the sum of the thickness of titanate nanosheet and the diameter of Mn ions. The yellow photocatalyst shows a spectral response in visible-light region and the calculated band gap is 2.59 eV. The photocatalytic performance of this material was evaluated by degradation and mineralization of an aqueous dye methylene blue under visible-light irradiation, and an enhanced photocatalytic activity in comparison with protonated titanate as well as the P25 TiO 2 and N-doped TiO 2 was obtained. Additionally, the layered structure is retained, no dye ions intercalating occurs during the photocatalysis process, and a ∼90% photocatalytic activity can be remained after reusing 3 cycles. - Graphical abstract: Mn-intercalated layered titanate as a novel and efficient visible-light harvesting photocatalyst was synthesized via a convenient and efficient exfoliation–flocculation approach in a mild condition. Highlights: ► Mn-intercalated titanate has been prepared by exfoliation–flocculation approach. ► The as-prepared catalyst shows spectral response in the visible-light region. ► Heat treatment at certain temperature enables formation of Mn-doped TiO 2 . ► Dye can be degradated effectively by the catalyst under visible light irradiation.

  14. "Heart Shots": a classroom activity to instigate active learning.

    Science.gov (United States)

    Abraham, Reem Rachel; Vashe, Asha; Torke, Sharmila

    2015-09-01

    The present study aimed to provide undergraduate medical students at Melaka Manipal Medical College (Manipal Campus), Manipal University, in Karnataka, India, an opportunity to apply their knowledge in cardiovascular concepts to real-life situations. A group activity named "Heart Shots" was implemented for a batch of first-year undergraduate students (n = 105) at the end of a block (teaching unit). Students were divided into 10 groups each having 10-11 students. They were requested to make a video/PowerPoint presentation about the application of cardiovascular principles to real-life situations. The presentation was required to be of only pictures/photos and no text material, with a maximum duration of 7 min. More than 95% of students considered that the activity helped them to apply their knowledge in cardiovascular concepts to real-life situations and understand the relevance of physiology in medicine and to revise the topic. More than 90% of students agreed that the activity helped them to apply their creativity in improving their knowledge and to establish a link between concepts rather than learning them as isolated facts. Based on the feedback, we conclude that the activity was student centered and that it facilitated learning. Copyright © 2015 The American Physiological Society.

  15. Stress recovery and cyclic behaviour of an Fe-Mn-Si shape memory alloy after multiple thermal activation

    Science.gov (United States)

    Hosseini, E.; Ghafoori, E.; Leinenbach, C.; Motavalli, M.; Holdsworth, S. R.

    2018-02-01

    The stress recovery and cyclic deformation behaviour of Fe-17Mn-5Si-10Cr-4Ni-1(V,C) shape memory alloy (Fe-SMA) strips, which are often used for pre-stressed strengthening of structural members, were studied. The evolution of recovery stress under different constraint conditions was studied. The results showed that the magnitude of the tensile stress in the Fe-SMA member during thermal activation can have a signification effect on the final recovery stress. The higher the tensile load in the Fe-SMA (e.g., caused by dead load or thermal expansion of parent structure during heating phase), the lower the final recovery stress. Furthermore, this study investigated the cyclic behaviour of the activated SMA followed by a second thermal activation. Although the magnitude of the recovery stress decreased during the cyclic loading, the second thermal activation could retrieve a significant part of the relaxed recovery stress. This observation suggests that the relaxation of recovery stress during cyclic loading is due to a reversible phase transformation-induced deformation (i.e., forward austenite-to-martensite transformation) rather than an irreversible dislocation-induced plasticity. Retrieval of the relaxed recovery stress by the reactivation process has important practical implications as the prestressing loss in pre-stressed civil structures can be simply recovered by reheating of the Fe-SMA elements.

  16. Effect of N+ beam exposure on the activities of Mn-SOD and catalase in deinococcus radiodurans

    International Nuclear Information System (INIS)

    Song Daojun; Chen Ruolei; Wu Lifang; Li Hong; Yao JIanming; Shao Chunlin; Wu Lijun; Yu Zengliang

    2000-01-01

    Though the radiation-resistant bacteria Deinococcus radiodurans (D. radiodurans) have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. The superoxide dismutase (SOD) and catalase (CAT) activities produced in bacteria (D. radiodurans AS1.633) and their change caused by 20 keV N'+ beam exposure were examined. Results showed that the activities of the enzymes were increased in the case of N + beam exposure from 8 x 10 14 ions/cm 2 to 6 x 10 15 ions/cm 2 . In addition, the treatment of H 2 O 2 and [CHCl 3 + CH 3 CH 2 OH] and the measurement of absorption spectrum showed that the increase of whole SOD activity resulted from inducible activities of Mn-SOD in (a sub-type) D. radiodurans AS1.633. These results suggested that these bacteria possess inducible defense mechanisms against the deleterious effects of oxidization

  17. Active Affordance Learning in Continuous State and Action Spaces

    NARCIS (Netherlands)

    Wang, C.; Hindriks, K.V.; Babuska, R.

    2014-01-01

    Learning object affordances and manipulation skills is essential for developing cognitive service robots. We propose an active affordance learning approach in continuous state and action spaces without manual discretization of states or exploratory motor primitives. During exploration in the action

  18. An Analysis of Learning Activities in a Technology Education Textbook for Teachers : Learning Process Based on Contents Framework and Learning Scene to Develop Technological Literacy

    OpenAIRE

    Yata, Chikahiko; Hamamoto, Kengo; Oguri, Takenori

    2014-01-01

    This study analyzed the learning activities in a textbook on technology education for teachers, in order to examine the learning processes and learning scenes detailed therein. Results of analyzing learning process, primary learning activity found each contents framework. Other learning activities designated to be related to complementary in learning process. Results of analyzing learning scene, 14 learning scenes, among them "Scene to recognize the impact on social life and progress of techn...

  19. Lifeguard Final Exam—Encouraging the Use of Active Learning

    OpenAIRE

    Griswold, Elise N.; Klionsky, Daniel J.

    2015-01-01

    To anyone familiar with the extensive literature on teaching and learning, there is little question that active learning is more effective than passive learning. Thus, we are not directing this letter to that particular audience. Instead, we are attempting to address the question of the best way to convince instructors who have not tried to incorporate elements of active learning into their courses to make such an attempt. There are numerous examples where it becomes immediately clear that ac...

  20. Is Active Learning Like Broccoli? Student Perceptions of Active Learning in Large Lecture Classes

    Science.gov (United States)

    Smith, C. Veronica; Cardaciotto, LeeAnn

    2011-01-01

    Although research suggests that active learning is associated with positive outcomes (e.g., memory, test performance), use of such techniques can be difficult to implement in large lecture-based classes. In the current study, 1,091 students completed out-of-class group exercises to complement course material in an Introductory Psychology class.…

  1. Cooperative activity and its potential for learning in tertiary education

    Directory of Open Access Journals (Sweden)

    Cirila Peklaj

    2007-01-01

    Full Text Available A learning situation can be structured in different ways, as an individual, competitive, or cooperative activity. Each of these structures can be used for different purposes and can lead to different learning outcomes. This paper focuses on cooperative activity and its potential for learning in tertiary education. After defining cooperative activity (or, in a broader sense, learning in interaction and introducing the CAMS theoretical framework to analyse cooperative activity, the main discussion focuses on the theoretical reasons for the usefulness of group learning and on the research of effects of cooperative learning on cognitive (metacognitive, affective-motivational and social processes in university students. The key elements that should be established for successful cooperation are also discussed. At the end, a new direction in using cooperative activity in learning—computer supported collaborative learning (CSCL, which emerged with rapid technology development in the last two decades—is presented and discussed.

  2. Students' Satisfaction on Their Learning Process in Active Learning and Traditional Classrooms

    Science.gov (United States)

    Hyun, Jung; Ediger, Ruth; Lee, Donghun

    2017-01-01

    Studies have shown Active Learning Classrooms [ALCs] help increase student engagement and improve student performance. However, remodeling all traditional classrooms to ALCs entails substantial financial burdens. Thus, an imperative question for institutions of higher education is whether active learning pedagogies can improve learning outcomes…

  3. Active-Learning versus Teacher-Centered Instruction for Learning Acids and Bases

    Science.gov (United States)

    Sesen, Burcin Acar; Tarhan, Leman

    2011-01-01

    Background and purpose: Active-learning as a student-centered learning process has begun to take more interest in constructing scientific knowledge. For this reason, this study aimed to investigate the effectiveness of active-learning implementation on high-school students' understanding of "acids and bases". Sample: The sample of this…

  4. Lifeguard Final Exam—Encouraging the Use of Active Learning

    Directory of Open Access Journals (Sweden)

    Elise N. Griswold

    2015-08-01

    Full Text Available To anyone familiar with the extensive literature on teaching and learning, there is little question that active learning is more effective than passive learning. Thus, we are not directing this letter to that particular audience. Instead, we are attempting to address the question of the best way to convince instructors who have not tried to incorporate elements of active learning into their courses to make such an attempt. There are numerous examples where it becomes immediately clear that active learning is preferable to a lecture/note-taking approach. Here, we provide a question for group discussion that can be used as one such illustration.

  5. Investigation on the electrochemical activation process of Li1.20Ni0.32Co0.004Mn0.476O2

    Directory of Open Access Journals (Sweden)

    Daichun Tang

    2014-08-01

    Full Text Available The lithium-rich layered oxides are one of the most attractive cathode materials for lithium-ion batteries. Here, two types of Li1.20Ni0.32Co0.004Mn0.476O2 were synthesized using Li2CO3 and LiOH as lithium sources. An electrochemical activation process occurs in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from Li2CO3 (LLO-1, while no obvious activation in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from LiOH (LLO-2 is observed. Via advanced scanning transmission electron microscopy (STEM, we found that Li2MnO3-like structure is rich in the surface region of LLO-2. The study provides a direct explanation for the electrochemical activation of lithium-rich materials. The sample with more LiMO2-like phase at the surface region shows a better cycling performance. It is likely that more LiMO2-like phase at the surface region could stabilize the interface and improve the cycling performance of the Li-rich cathode materials.

  6. Mixed bi-material electrodes based on LiMn2O4 and activated carbon for hybrid electrochemical energy storage devices

    International Nuclear Information System (INIS)

    Cericola, Dario; Novak, Petr; Wokaun, Alexander; Koetz, Ruediger

    2011-01-01

    Highlights: → Bi-material electrodes for electrochemical hybrid devices were characterized. → Bi-material electrodes have higher specific charge than capacitor electrodes. → Bi-material electrodes have better rate capability than battery electrodes. → Bi-material systems outperform batteries and capacitors in pulsed applications. - Abstract: The performance of mixed bi-material electrodes composed of the battery material, LiMn 2 O 4 , and the electrochemical capacitor material, activated carbon, for hybrid electrochemical energy storage devices is investigated by galvanostatic charge/discharge and pulsed discharge experiments. Both, a high and a low conductivity lithium-containing electrolyte are used. The specific charge of the bi-material electrode is the linear combination of the specific charges of LiMn 2 O 4 and activated carbon according to the electrode composition at low discharge rates. Thus, the specific charge of the bi-material electrode falls between the specific charge of the activated carbon electrode and the LiMn 2 O 4 battery electrode. The bi-material electrodes have better rate capability than the LiMn 2 O 4 battery electrode. For high current pulsed applications the bi-material electrodes typically outperform both the battery and the capacitor electrode.

  7. Empathy and feedback processing in active and observational learning.

    Science.gov (United States)

    Rak, Natalia; Bellebaum, Christian; Thoma, Patrizia

    2013-12-01

    The feedback-related negativity (FRN) and the P300 have been related to the processing of one's own and other individuals' feedback during both active and observational learning. The aim of the present study was to elucidate the role of trait-empathic responding with regard to the modulation of the neural correlates of observational learning in particular. Thirty-four healthy participants completed an active and an observational learning task. On both tasks, the participants' aim was to maximize their monetary gain by choosing from two stimuli the one that showed the higher probability of reward. Participants gained insight into the stimulus-reward contingencies according to monetary feedback presented after they had made an active choice or by observing the choices of a virtual partner. Participants showed a general improvement in learning performance on both learning tasks. P200, FRN, and P300 amplitudes were larger during active, as compared with observational, learning. Furthermore, nonreward elicited a significantly more negative FRN than did reward in the active learning task, while only a trend was observed for observational learning. Distinct subcomponents of trait cognitive empathy were related to poorer performance and smaller P300 amplitudes for observational learning only. Taken together, both the learning performance and event-related potentials during observational learning are affected by different aspects of trait cognitive empathy, and certain types of observational learning may actually be disrupted by a higher tendency to understand and adopt other people's perspectives.

  8. The colloquial approach: An active learning technique

    Science.gov (United States)

    Arce, Pedro

    1994-09-01

    This paper addresses the very important problem of the effectiveness of teaching methodologies in fundamental engineering courses such as transport phenomena. An active learning strategy, termed the colloquial approach, is proposed in order to increase student involvement in the learning process. This methodology is a considerable departure from traditional methods that use solo lecturing. It is based on guided discussions, and it promotes student understanding of new concepts by directing the student to construct new ideas by building upon the current knowledge and by focusing on key cases that capture the essential aspects of new concepts. The colloquial approach motivates the student to participate in discussions, to develop detailed notes, and to design (or construct) his or her own explanation for a given problem. This paper discusses the main features of the colloquial approach within the framework of other current and previous techniques. Problem-solving strategies and the need for new textbooks and for future investigations based on the colloquial approach are also outlined.

  9. Do International Students Appreciate Active Learning in Lectures?

    Directory of Open Access Journals (Sweden)

    Mauricio Marrone

    2018-03-01

    Full Text Available Active learning has been linked with increased student motivation, engagement and understanding of course material. It promotes deep learning, helping to develop critical thinking and writing skills in students. Less well understood, however, are the responses of international students to active learning. Using social constructivist theory, the purpose of this study is to examine domestic and international student perceptions of active learning introduced into large undergraduate Accounting Information Systems lectures. Several active learning strategies were implemented over one semester and examined through the use of semi-structured interviews as well as pre- and post- implementation surveys. Our results suggest broad improvements for international students in student engagement and understanding of unit material when implementing active learning strategies. Other key implications include international student preference for active learning compared with passive learning styles, and that international students may receive greater benefits from active learning strategies than domestic students due to social factors. Based on these findings this paper proposes that educators should seek to implement active learning to better assist and integrate students of diverse backgrounds.

  10. The Use of "Socrative" in ESL Classrooms: Towards Active Learning

    Science.gov (United States)

    El Shaban, Abir

    2017-01-01

    The online student response system (SRS) is a technological tool that can be effectively implemented in English language classroom contexts and be used to promote students' active learning. In this qualitative study, "Socrative", a Web 2.0 software, was integrated with active learning activities and used as an SRS to explore English…

  11. Active Learning and Teaching: Improving Postsecondary Library Instruction.

    Science.gov (United States)

    Allen, Eileen E.

    1995-01-01

    Discusses ways to improve postsecondary library instruction based on theories of active learning. Topics include a historical background of active learning; student achievement and attitudes; cognitive development; risks; active teaching; and instructional techniques, including modified lectures, brainstorming, small group work, cooperative…

  12. Is engagement with a purpose the essence of active learning?

    OpenAIRE

    Álvarez Mesa, Mauricio

    2009-01-01

    In the 2009 edition of the conference on “Active Learning in Engineering Education”, there were several and fruitful discussions within a small workgroup about the essence of active learning. At the end we came with an attempt to sum up our whole discussion with one question. Our question is the same as the title of this essay. Taking this question as a starting point this article propose a specific purpose from which active learning can be based. Peer Reviewed

  13. Generation of Tutorial Dialogues: Discourse Strategies for Active Learning

    Science.gov (United States)

    1998-05-29

    AND SUBTITLE Generation of Tutorial Dialogues: Discourse Strategies for active Learning AUTHORS Dr. Martha Evens 7. PERFORMING ORGANI2ATION NAME...time the student starts in on a new topic. Michael and Rovick constantly attempt to promote active learning . They regularly use hints and only resort...Controlling active learning : How tutors decide when to generate hints. Proceedings of FLAIRS 󈨣. Melbourne Beach, FL. 157-161. Hume, G., Michael

  14. Learning by Doing: Twenty Successful Active Learning Exercises for Information Systems Courses

    Directory of Open Access Journals (Sweden)

    Alanah Mitchell

    2017-01-01

    Full Text Available Aim/Purpose: This paper provides a review of previously published work related to active learning in information systems (IS courses. Background: There are a rising number of strategies in higher education that offer promise in regards to getting students’ attention and helping them learn, such as flipped classrooms and offering courses online. These learning strategies are part of the pedagogical technique known as active learning. Active learning is a strategy that became popular in the early 1990s and has proven itself as a valid tool for helping students to be engaged with learning. Methodology: This work follows a systematic method for identifying and coding previous research based on an aspect of interest. The authors identified and assessed research through a search of ABI/Inform scholarly journal abstracts and keywords, as well as additional research databases, using the search terms “active learning” and “information systems” from 2000 through June 2016. Contribution: This synthesis of active learning exercises provides guidance for information technology faculty looking to implement active learning strategies in their classroom by demonstrating how IS faculty might begin to introduce more active learning techniques in their teaching as well as by presenting a sample teaching agenda for a class that uses a mix of active and passive learning techniques to engage student learning. Findings: Twenty successful types of active learning exercises in IS courses are presented. Recommendations for Practitioners\t: This paper offers a “how to” resource of successful active learning strategies for IS faculty interested in implementing active learning in the classroom. Recommendation for Researchers: This work provides an example of a systematic literature review as a means to assess successful implementations of active learning in IS. Impact on Society: An updated definition of active learning is presented as well as a meaningful

  15. [Effect of Mn(II) on the error-prone DNA polymerase iota activity in extracts from human normal and tumor cells].

    Science.gov (United States)

    Lakhin, A V; Efremova, A S; Makarova, I V; Grishina, E E; Shram, S I; Tarantul, V Z; Gening, L V

    2013-01-01

    The DNA polymerase iota (Pol iota), which has some peculiar features and is characterized by an extremely error-prone DNA synthesis, belongs to the group of enzymes preferentially activated by Mn2+ instead of Mg2+. In this work, the effect of Mn2+ on DNA synthesis in cell extracts from a) normal human and murine tissues, b) human tumor (uveal melanoma), and c) cultured human tumor cell lines SKOV-3 and HL-60 was tested. Each group displayed characteristic features of Mn-dependent DNA synthesis. The changes in the Mn-dependent DNA synthesis caused by malignant transformation of normal tissues are described. It was also shown that the error-prone DNA synthesis catalyzed by Pol iota in extracts of all cell types was efficiently suppressed by an RNA aptamer (IKL5) against Pol iota obtained in our work earlier. The obtained results suggest that IKL5 might be used to suppress the enhanced activity of Pol iota in tumor cells.

  16. Performance in Physiology Evaluation: Possible Improvement by Active Learning Strategies

    Science.gov (United States)

    Montrezor, Luís H.

    2016-01-01

    The evaluation process is complex and extremely important in the teaching/learning process. Evaluations are constantly employed in the classroom to assist students in the learning process and to help teachers improve the teaching process. The use of active methodologies encourages students to participate in the learning process, encourages…

  17. Teacher Feedback during Active Learning: Current Practices in Primary Schools

    Science.gov (United States)

    van den Bergh, Linda; Ros, Anje; Beijaard, Douwe

    2013-01-01

    Background: Feedback is one of the most powerful tools, which teachers can use to enhance student learning. It appears dif?cult for teachers to give qualitatively good feedback, especially during active learning. In this context, teachers should provide facilitative feedback that is focused on the development of meta-cognition and social learning.…

  18. Assessing Student Behaviors and Motivation for Actively Learning Biology

    Science.gov (United States)

    Moore, Michael Edward

    Vision and Change states that one of the major changes in the way we design biology courses should be a switch in approach from teacher-centered learning to student-centered learning and identifies active learning as a recommended methods. Studies show performance benefits for students taking courses that use active learning. What is unknown is why active learning is such an effective instructional tool and the limits of this instructional method’s ability to influence performance. This dissertation builds a case in three steps for why active learning is an effective instructional tool. In step one, I assessed the influence of different types of active learning (clickers, group activities, and whole class discussions) on student engagement behavior in one semester of two different introductory biology courses and found that active learning positively influenced student engagement behavior significantly more than lecture. For step two, I examined over four semesters whether student engagement behavior was a predictor of performance and found participation (engagement behavior) in the online (video watching) and in-class course activities (clicker participation) that I measure were significant predictors of performance. In the third, I assessed whether certain active learning satisfied the psychological needs that lead to students’ intrinsic motivation to participate in those activities when compared over two semesters and across two different institutions of higher learning. Findings from this last step show us that student’s perceptions of autonomy, competency, and relatedness in doing various types of active learning are significantly higher than lecture and consistent across two institutions of higher learning. Lastly, I tie everything together, discuss implications of the research, and address future directions for research on biology student motivation and behavior.

  19. CORRELATION OF THE FERMI ENERGY OF Ni, Cr, Mn WITH THE ELECTROCATALYTIC ACTIVITY OF THE TRIPLE ALLOYS ON THE BASE OF THESE METALS

    Directory of Open Access Journals (Sweden)

    A. D. Andreyanov

    2016-04-01

    Full Text Available It was established the dependence of the electrocatalytic activity of alloys Ni-Cr-Mn at the variable contents of copper with values of Fermy energy of their components. Electrocatalytic activity of alloys was estimated by density of the current, determined by the method of suspended half-element. For Fermi energy calculation of various metals Sommerfeld model, in which distribution of electrons by speed is described by Fermi-Dirac statistic was used.

  20. Pedagogical Distance: Explaining Misalignment in Student-Driven Online Learning Activities Using Activity Theory

    Science.gov (United States)

    Westberry, Nicola; Franken, Margaret

    2015-01-01

    This paper provides an Activity Theory analysis of two online student-driven interactive learning activities to interrogate assumptions that such groups can effectively learn in the absence of the teacher. Such an analysis conceptualises learning tasks as constructed objects that drive pedagogical activity. The analysis shows a disconnect between…

  1. An Innovative Teaching Method To Promote Active Learning: Team-Based Learning

    Science.gov (United States)

    Balasubramanian, R.

    2007-12-01

    Traditional teaching practice based on the textbook-whiteboard- lecture-homework-test paradigm is not very effective in helping students with diverse academic backgrounds achieve higher-order critical thinking skills such as analysis, synthesis, and evaluation. Consequently, there is a critical need for developing a new pedagogical approach to create a collaborative and interactive learning environment in which students with complementary academic backgrounds and learning skills can work together to enhance their learning outcomes. In this presentation, I will discuss an innovative teaching method ('Team-Based Learning (TBL)") which I recently developed at National University of Singapore to promote active learning among students in the environmental engineering program with learning abilities. I implemented this new educational activity in a graduate course. Student feedback indicates that this pedagogical approach is appealing to most students, and promotes active & interactive learning in class. Data will be presented to show that the innovative teaching method has contributed to improved student learning and achievement.

  2. Sharing the learning activity using intelligent CAD

    DEFF Research Database (Denmark)

    Duffy, S. M.; Duffy, Alex

    1996-01-01

    In this paper the need for Intelligent Computer Aided Design (Int.CAD) to jointly support design and learning assistance is introduced. The paper focuses on presenting and exploring the possibility of realizing ''learning'' assistance in Int.CAD by introducing a new concept called Shared Learning...

  3. The control of tonic pain by active relief learning.

    Science.gov (United States)

    Zhang, Suyi; Mano, Hiroaki; Lee, Michael; Yoshida, Wako; Kawato, Mitsuo; Robbins, Trevor W; Seymour, Ben

    2018-02-27

    Tonic pain after injury characterises a behavioural state that prioritises recovery. Although generally suppressing cognition and attention, tonic pain needs to allow effective relief learning to reduce the cause of the pain. Here, we describe a central learning circuit that supports learning of relief and concurrently suppresses the level of ongoing pain. We used computational modelling of behavioural, physiological and neuroimaging data in two experiments in which subjects learned to terminate tonic pain in static and dynamic escape-learning paradigms. In both studies, we show that active relief-seeking involves a reinforcement learning process manifest by error signals observed in the dorsal putamen. Critically, this system uses an uncertainty ('associability') signal detected in pregenual anterior cingulate cortex that both controls the relief learning rate, and endogenously and parametrically modulates the level of tonic pain. The results define a self-organising learning circuit that reduces ongoing pain when learning about potential relief. © 2018, Zhang et al.

  4. The control of tonic pain by active relief learning

    Science.gov (United States)

    Mano, Hiroaki; Lee, Michael; Yoshida, Wako; Kawato, Mitsuo; Robbins, Trevor W

    2018-01-01

    Tonic pain after injury characterises a behavioural state that prioritises recovery. Although generally suppressing cognition and attention, tonic pain needs to allow effective relief learning to reduce the cause of the pain. Here, we describe a central learning circuit that supports learning of relief and concurrently suppresses the level of ongoing pain. We used computational modelling of behavioural, physiological and neuroimaging data in two experiments in which subjects learned to terminate tonic pain in static and dynamic escape-learning paradigms. In both studies, we show that active relief-seeking involves a reinforcement learning process manifest by error signals observed in the dorsal putamen. Critically, this system uses an uncertainty (‘associability’) signal detected in pregenual anterior cingulate cortex that both controls the relief learning rate, and endogenously and parametrically modulates the level of tonic pain. The results define a self-organising learning circuit that reduces ongoing pain when learning about potential relief. PMID:29482716

  5. Active Learning for Autonomous Intelligent Agents: Exploration, Curiosity, and Interaction

    OpenAIRE

    Lopes, Manuel; Montesano, Luis

    2014-01-01

    In this survey we present different approaches that allow an intelligent agent to explore autonomous its environment to gather information and learn multiple tasks. Different communities proposed different solutions, that are in many cases, similar and/or complementary. These solutions include active learning, exploration/exploitation, online-learning and social learning. The common aspect of all these approaches is that it is the agent to selects and decides what information to gather next. ...

  6. Active learning: a step towards automating medical concept extraction.

    Science.gov (United States)

    Kholghi, Mahnoosh; Sitbon, Laurianne; Zuccon, Guido; Nguyen, Anthony

    2016-03-01

    This paper presents an automatic, active learning-based system for the extraction of medical concepts from clinical free-text reports. Specifically, (1) the contribution of active learning in reducing the annotation effort and (2) the robustness of incremental active learning framework across different selection criteria and data sets are determined. The comparative performance of an active learning framework and a fully supervised approach were investigated to study how active learning reduces the annotation effort while achieving the same effectiveness as a supervised approach. Conditional random fields as the supervised method, and least confidence and information density as 2 selection criteria for active learning framework were used. The effect of incremental learning vs standard learning on the robustness of the models within the active learning framework with different selection criteria was also investigated. The following 2 clinical data sets were used for evaluation: the Informatics for Integrating Biology and the Bedside/Veteran Affairs (i2b2/VA) 2010 natural language processing challenge and the Shared Annotated Resources/Conference and Labs of the Evaluation Forum (ShARe/CLEF) 2013 eHealth Evaluation Lab. The annotation effort saved by active learning to achieve the same effectiveness as supervised learning is up to 77%, 57%, and 46% of the total number of sequences, tokens, and concepts, respectively. Compared with the random sampling baseline, the saving is at least doubled. Incremental active learning is a promising approach for building effective and robust medical concept extraction models while significantly reducing the burden of manual annotation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Electrochemically active MnO{sub 2} coated Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2} cathode with highly improved initial coulombic efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Yanling; Xu, Youlong, E-mail: ylxu@mail.xjtu.edu.cn; Sun, Xiaofei; Xiong, Lilong; Mao, Shengchun

    2016-10-30

    Highlights: • MnO{sub 2} was used to coat lithium-rich layered oxide Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2}. • MnO{sub 2} is electrochemically active and became spinel phase after cycles. • MnO{sub 2}-coated material shows noticeably improved initial coulombic efficiency. • Specific capacities and rate performances could also be enhanced by MnO{sub 2} coating. - Abstract: Lithium-rich layered oxide is known to be one of the most promising positive electrode materials for lithium ion batteries due to its large capacity and high energy density. However, low initial coulombic efficiency is currently an urgent problem hindering its practical application. In this work, electrochemically active MnO{sub 2} coating was used to improve the coulombic efficiency of Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2}. Firstly, the pristine material was synthesized via co-precipitation following by solid-state calcination. Then MnO{sub 2}-coated Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2} was prepared by heat treatment of the mixture of pristine powder and manganese nitrate. During first discharging, lithium ions can intercalate into not only the delithiated Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2} but also the MnO{sub 2} coating, thus noticeably improves the coulombic efficiency and discharge capacity. The initial efficiency is enhanced from 61.2% (pristine) to 84.4%, 88.8% and 95.4%, respectively, for 10 wt.%, 15 wt.% and 20 wt.% MnO{sub 2} coated Li{sub 1.2}Ni{sub 0.18}Co{sub 0.04}Mn{sub 0.58}O{sub 2} at 20 mA g{sup −1}. Furthermore, the 15 wt.% MnO{sub 2} coated sample delivers an initial discharge capacity as high as 294.4 mAh g{sup −1}.

  8. Enhancing students' learning in problem based learning: validation of a self-assessment scale for active learning and critical thinking

    NARCIS (Netherlands)

    Khoiriyah, U.; Roberts, C.; Jorm, C.; Vleuten, C.P. van der

    2015-01-01

    BACKGROUND: Problem based learning (PBL) is a powerful learning activity but fidelity to intended models may slip and student engagement wane, negatively impacting learning processes, and outcomes. One potential solution to solve this degradation is by encouraging self-assessment in the PBL

  9. Group-Based Active Learning of Classification Models.

    Science.gov (United States)

    Luo, Zhipeng; Hauskrecht, Milos

    2017-05-01

    Learning of classification models from real-world data often requires additional human expert effort to annotate the data. However, this process can be rather costly and finding ways of reducing the human annotation effort is critical for this task. The objective of this paper is to develop and study new ways of providing human feedback for efficient learning of classification models by labeling groups of examples. Briefly, unlike traditional active learning methods that seek feedback on individual examples, we develop a new group-based active learning framework that solicits label information on groups of multiple examples. In order to describe groups in a user-friendly way, conjunctive patterns are used to compactly represent groups. Our empirical study on 12 UCI data sets demonstrates the advantages and superiority of our approach over both classic instance-based active learning work, as well as existing group-based active-learning methods.

  10. Experiential Learning and Learning Environments: The Case of Active Listening Skills

    Science.gov (United States)

    Huerta-Wong, Juan Enrique; Schoech, Richard

    2010-01-01

    Social work education research frequently has suggested an interaction between teaching techniques and learning environments. However, this interaction has never been tested. This study compared virtual and face-to-face learning environments and included active listening concepts to test whether the effectiveness of learning environments depends…

  11. Collegewide Promotion of E-Learning/Active Learning and Faculty Development

    Science.gov (United States)

    Ogawa, Nobuyuki; Shimizu, Akira

    2016-01-01

    Japanese National Institutes of Technology have revealed a plan to strongly promote e-Learning and active learning under the common schematization of education in over 50 campuses nationwide. Our e-Learning and ICT-driven education practiced for more than fifteen years were highly evaluated, and is playing a leading role in promoting e-Learning…

  12. Asymmetric supercapacitors based on graphene/MnO{sub 2} and activated carbon nanofiber electrodes with high power and energy density

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhuangjun; Yan, Jun; Wei, Tong; Li, Tianyou [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhi, Linjie [National Center for Nanoscience and Technology of China, Zhongguancun, Beiyitiao 11, Beijing 100190 (China); Ning, Guoqing [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Wei, Fei [Beijing Key Laboratory of Green Chemical Reaction, Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2011-06-21

    Asymmetric supercapacitor with high energy density has been developed successfully using graphene/MnO{sub 2} composite as positive electrode and activated carbon nanofibers (ACN) as negative electrode in a neutral aqueous Na{sub 2}SO{sub 4} electrolyte. Due to the high capacitances and excellent rate performances of graphene/MnO{sub 2} and ACN, as well as the synergistic effects of the two electrodes, such asymmetric cell exhibits superior electrochemical performances. An optimized asymmetric supercapacitor can be cycled reversibly in the voltage range of 0-1.8 V, and exhibits maximum energy density of 51.1 Wh kg{sup -1}, which is much higher than that of MnO{sub 2}//DWNT cell (29.1 Wh kg{sup -1}). Additionally, graphene/MnO{sub 2}//ACN asymmetric supercapacitor exhibits excellent cycling durability, with 97% specific capacitance retained even after 1000 cycles. These encouraging results show great potential in developing energy storage devices with high energy and power densities for practical applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. The direct synthesis of mesoporous structured MnO2/TiO2 nanocomposite: a novel visible-light active photocatalyst with large pore size

    International Nuclear Information System (INIS)

    Xue Min; Huang Li; Wang Jianqiang; Wang Ying; Zou Zhigang; Gao Ling; Zhu Jianhua

    2008-01-01

    A series of visible-light-driven mesoporous structured MnO 2 /TiO 2 nanocrystal photocatalysts have been synthesized through a modified sol-gel method, and the N 2 adsorption-desorption isotherm confirms that the mesoporous materials possess large pore size (up to 9.2 nm) and a narrow pore size distribution. X-ray powder diffraction (XRD) analyses and complementary x-ray photoelectron spectroscopy (XPS) measurements reveal that the doping of the transition metal Mn inhibits the growth of TiO 2 anatase nanocrystals and the Mn species are highly dispersed on the surface of TiO 2 . The ultraviolet (UV)-vis spectrum demonstrates the excellent adsorption properties of MnO 2 /TiO 2 over the whole region of visible light, which enables this novel photocatalysis material to possess remarkable activity in the photocatalytic degradation of methylene blue under visible light radiation. Moreover, a 'coating mechanism' based on the nucleation of titania nanocrystals along with the interaction between the dopant precursors and titania clusters has been suggested

  14. The direct synthesis of mesoporous structured MnO2/TiO2 nanocomposite: a novel visible-light active photocatalyst with large pore size

    Science.gov (United States)

    Xue, Min; Huang, Li; Wang, Jian-Qiang; Wang, Ying; Gao, Ling; Zhu, Jian-hua; Zou, Zhi-Gang

    2008-05-01

    A series of visible-light-driven mesoporous structured MnO2/TiO2 nanocrystal photocatalysts have been synthesized through a modified sol-gel method, and the N2 adsorption-desorption isotherm confirms that the mesoporous materials possess large pore size (up to 9.2 nm) and a narrow pore size distribution. X-ray powder diffraction (XRD) analyses and complementary x-ray photoelectron spectroscopy (XPS) measurements reveal that the doping of the transition metal Mn inhibits the growth of TiO2 anatase nanocrystals and the Mn species are highly dispersed on the surface of TiO2. The ultraviolet (UV)-vis spectrum demonstrates the excellent adsorption properties of MnO2/TiO2 over the whole region of visible light, which enables this novel photocatalysis material to possess remarkable activity in the photocatalytic degradation of methylene blue under visible light radiation. Moreover, a 'coating mechanism' based on the nucleation of titania nanocrystals along with the interaction between the dopant precursors and titania clusters has been suggested.

  15. Examining factors affecting beginning teachers' transfer of learning of ICT-enhanced learning activities in their teaching practice

    NARCIS (Netherlands)

    Agyei, D.D.; Voogt, J.

    2014-01-01

    This study examined 100 beginning teachers’ transfer of learning when utilising Information Communication Technology-enhanced activity-based learning activities. The beginning teachers had participated in a professional development program that was characterised by ‘learning technology by

  16. Orchestration Framework for Learning Activities in Augmented Reality Environments

    OpenAIRE

    Ibáñez, María Blanca; Delgado Kloos, Carlos; Di Serio, Angela

    2011-01-01

    Proceedings of: Across Spaces11 Workshop in conjunction with the EC-TEL2011, Palermo, Italy, September 21, 2011 In this paper we show how Augmented Reality (AR) technology restricted to the use of mobiles or PCs, can be used to develop learning activities with the minimun level of orchestation required by meaningful learning sequences. We use Popcode as programming language to deploy orchestrated learning activities specified with an AR framework. Publicado

  17. Quantifying Local and Cooperative Components in the Ferroelectric Distortion of BaTiO3: Learning from the Off-Center Motion in the MnCl65– Complex Formed in KCl:Mn+

    DEFF Research Database (Denmark)

    García Lastra, Juan Maria; García-Fernández, P.; Calle-Vallejo, F.

    2014-01-01

    → C4v → Oh local transformations occurring in the 10–50 K temperature range for the MnCl65– complex formed in KCl:Mn+ that mimic the behavior of BaTiO3. From Boltzmann analysis of the vibronic levels derived from ab initio calculations and considering decoherence introduced by random strains......, the present calculations reproduce the experimental phase sequence and transition temperatures. Furthermore, our calculations show that the off-center instability in KCl:Mn+ would be suppressed by reducing by only 1% the lattice parameter, a situation that then becomes comparable to that found for BaTiO3...

  18. Teaching for Engagement: Part 3: Designing for Active Learning

    Science.gov (United States)

    Hunter, William J.

    2015-01-01

    In the first two parts of this series, ("Teaching for Engagement: Part 1: Constructivist Principles, Case-Based Teaching, and Active Learning") and ("Teaching for Engagement: Part 2: Technology in the Service of Active Learning"), William J. Hunter sought to outline the theoretical rationale and research basis for such active…

  19. Engaging Students in Large Health Classes with Active Learning Strategies

    Science.gov (United States)

    Elliott, Steven; Combs, Sue; Huelskamp, Amelia; Hritz, Nancy

    2017-01-01

    Creative K-12 health teachers can engage students in large classes by utilizing active learning strategies. Active learning involves engaging students in higher-order tasks, such as analysis and synthesis, which is a crucial element of the movement toward what is commonly called "learner-centered" teaching. Health education teachers who…

  20. Challenges Encountered in Creating Personalised Learning Activities to Suit Students Learning Preferences

    OpenAIRE

    O'Donnell, Eileen; Wade, Vincent; Sharp, Mary; O'Donnell, Liam

    2013-01-01

    This book chapter reviews some of the challenges encountered by educators in creating personalised e-learning activities to suit students learning preferences. Technology-enhanced learning (TEL) alternatively known as e-learning has not yet reached its full potential in higher education. There are still many potential uses as yet undiscovered and other discovered uses which are not yet realisable by many educators. TEL is still predominantly used for e-dissemination and e-administration. This...

  1. Magnetic Fe{sub 2}MO{sub 4} (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi Dung [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Phan, Ngoc Hoa [Department of Chemical Technology, Hochiminh University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh (Viet Nam); Do, Manh Huy, E-mail: huydoma@vast-hcm.ac.vn [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Ngo, Kim Tham [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); College of science, Can Tho University, 3/2, Can Tho (Viet Nam)

    2011-01-30

    We present a simple and efficient method for the fabrication of magnetic Fe{sub 2}MO{sub 4} (M:Fe and Mn) activated carbons (Fe{sub 2}MO{sub 4}/AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe{sub 2}MnO{sub 4}/AC-H showed higher catalytic activity in the methyl orange oxidation than Fe{sub 3}O{sub 4}/AC-H. The effect of operational parameters (pH, catalyst loading H{sub 2}O{sub 2} dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  2. Active learning for noisy oracle via density power divergence.

    Science.gov (United States)

    Sogawa, Yasuhiro; Ueno, Tsuyoshi; Kawahara, Yoshinobu; Washio, Takashi

    2013-10-01

    The accuracy of active learning is critically influenced by the existence of noisy labels given by a noisy oracle. In this paper, we propose a novel pool-based active learning framework through robust measures based on density power divergence. By minimizing density power divergence, such as β-divergence and γ-divergence, one can estimate the model accurately even under the existence of noisy labels within data. Accordingly, we develop query selecting measures for pool-based active learning using these divergences. In addition, we propose an evaluation scheme for these measures based on asymptotic statistical analyses, which enables us to perform active learning by evaluating an estimation error directly. Experiments with benchmark datasets and real-world image datasets show that our active learning scheme performs better than several baseline methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Theoretical investigation of the reaction of Mn+ with ethylene oxide.

    Science.gov (United States)

    Li, Yuanyuan; Guo, Wenyue; Zhao, Lianming; Liu, Zhaochun; Lu, Xiaoqing; Shan, Honghong

    2012-01-12

    The potential energy surfaces of Mn(+) reaction with ethylene oxide in both the septet and quintet states are investigated at the B3LYP/DZVP level of theory. The reaction paths leading to the products of MnO(+), MnO, MnCH(2)(+), MnCH(3), and MnH(+) are described in detail. Two types of encounter complexes of Mn(+) with ethylene oxide are formed because of attachments of the metal at different sites of ethylene oxide, i.e., the O atom and the CC bond. Mn(+) would insert into a C-O bond or the C-C bond of ethylene oxide to form two different intermediates prior to forming various products. MnO(+)/MnO and MnH(+) are formed in the C-O activation mechanism, while both C-O and C-C activations account for the MnCH(2)(+)/MnCH(3) formation. Products MnO(+), MnCH(2)(+), and MnH(+) could be formed adiabatically on the quintet surface, while formation of MnO and MnCH(3) is endothermic on the PESs with both spins. In agreement with the experimental observations, the excited state a(5)D is calculated to be more reactive than the ground state a(7)S. This theoretical work sheds new light on the experimental observations and provides fundamental understanding of the reaction mechanism of ethylene oxide with transition metal cations.

  4. Active Inference and Learning in the Cerebellum.

    Science.gov (United States)

    Friston, Karl; Herreros, Ivan

    2016-09-01

    This letter offers a computational account of Pavlovian conditioning in the cerebellum based on active inference and predictive coding. Using eyeblink conditioning as a canonical paradigm, we formulate a minimal generative model that can account for spontaneous blinking, startle responses, and (delay or trace) conditioning. We then establish the face validity of the model using simulated responses to unconditioned and conditioned stimuli to reproduce the sorts of behavior that are observed empirically. The scheme's anatomical validity is then addressed by associating variables in the predictive coding scheme with nuclei and neuronal populations to match the (extrinsic and intrinsic) connectivity of the cerebellar (eyeblink conditioning) system. Finally, we try to establish predictive validity by reproducing selective failures of delay conditioning, trace conditioning, and extinction using (simulated and reversible) focal lesions. Although rather metaphorical, the ensuing scheme can account for a remarkable range of anatomical and neurophysiological aspects of cerebellar circuitry-and the specificity of lesion-deficit mappings that have been established experimentally. From a computational perspective, this work shows how conditioning or learning can be formulated in terms of minimizing variational free energy (or maximizing Bayesian model evidence) using exactly the same principles that underlie predictive coding in perception.

  5. Reconstructing Causal Biological Networks through Active Learning.

    Directory of Open Access Journals (Sweden)

    Hyunghoon Cho

    Full Text Available Reverse-engineering of biological networks is a central problem in systems biology. The use of intervention data, such as gene knockouts or knockdowns, is typically used for teasing apart causal relationships among genes. Under time or resource constraints, one needs to carefully choose which intervention experiments to carry out. Previous approaches for selecting most informative interventions have largely been focused on discrete Bayesian networks. However, continuous Bayesian networks are of great practical interest, especially in the study of complex biological systems and their quantitative properties. In this work, we present an efficient, information-theoretic active learning algorithm for Gaussian Bayesian networks (GBNs, which serve as important models for gene regulatory networks. In addition to providing linear-algebraic insights unique to GBNs, leading to significant runtime improvements, we demonstrate the effectiveness of our method on data simulated with GBNs and the DREAM4 network inference challenge data sets. Our method generally leads to faster recovery of underlying network structure and faster convergence to final distribution of confidence scores over candidate graph structures using the full data, in comparison to random selection of intervention experiments.

  6. Resting alpha activity predicts learning ability in alpha neurofeedback

    Directory of Open Access Journals (Sweden)

    Wenya eNan

    2014-07-01

    Full Text Available Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the training parameter changes between two periods, within a short period and across the whole training time. It was found that the resting alpha amplitude measured before training had significant positive correlations with all learning indices and could be used as a predictor for the learning ability prediction. This finding would help the researchers in not only predicting the training efficacy in individuals but also gaining further insight into the mechanisms of alpha neurofeedback.

  7. Mapping Learning Outcomes and Assignment Tasks for SPIDER Activities

    Directory of Open Access Journals (Sweden)

    Lyn Brodie

    2011-05-01

    Full Text Available Modern engineering programs have to address rapidly changing technical content and have to enable students to develop transferable skills such as critical evaluation, communication skills and lifelong learning. This paper introduces a combined learning and assessment activity that provides students with opportunities to develop and practice their soft skills, but also extends their theoretical knowledge base. Key tasks included self directed inquiry, oral and written communication as well as peer assessment. To facilitate the SPIDER activities (Select, Prepare and Investigate, Discuss, Evaluate, Reflect, a software tool has been implemented in the learning management system Moodle. Evidence shows increased student engagement and better learning outcomes for both transferable as well as technical skills. The study focuses on generalising the relationship between learning outcomes and assignment tasks as well as activities that drive these tasks. Trail results inform the approach. Staff evaluations and their views of assignments and intended learning outcomes also supported this analysis.

  8. Postnatal TLR2 activation impairs learning and memory in adulthood.

    Science.gov (United States)

    Madar, Ravit; Rotter, Aviva; Waldman Ben-Asher, Hiba; Mughal, Mohamed R; Arumugam, Thiruma V; Wood, W H; Becker, K G; Mattson, Mark P; Okun, Eitan

    2015-08-01

    Neuroinflammation in the central nervous system is detrimental for learning and memory, as evident form epidemiological studies linking developmental defects and maternal exposure to harmful pathogens. Postnatal infections can also induce neuroinflammatory responses with long-term consequences. These inflammatory responses can lead to motor deficits and/or behavioral disabilities. Toll like receptors (TLRs) are a family of innate immune receptors best known as sensors of microbial-associated molecular patterns, and are the first responders to infection. TLR2 forms heterodimers with either TLR1 or TLR6, is activated in response to gram-positive bacterial infections, and is expressed in the brain during embryonic development. We hypothesized that early postnatal TLR2-mediated neuroinflammation would adversely affect cognitive behavior in the adult. Our data indicate that postnatal TLR2 activation affects learning and memory in adult mice in a heterodimer-dependent manner. TLR2/6 activation improved motor function and fear learning, while TLR2/1 activation impaired spatial learning and enhanced fear learning. Moreover, developmental TLR2 deficiency significantly impairs spatial learning and enhances fear learning, stressing the involvement of the TLR2 pathway in learning and memory. Analysis of the transcriptional effects of TLR2 activation reveals both common and unique transcriptional programs following heterodimer-specific TLR2 activation. These results imply that adult cognitive behavior could be influenced in part, by activation or alterations in the TLR2 pathway at birth. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Is there a relationship between the stacking fault character and the activated mode of plasticity of Fe-Mn-based austenitic steels?

    International Nuclear Information System (INIS)

    Idrissi, H.; Ryelandt, L.; Veron, M.; Schryvers, D.; Jacques, P.J.

    2009-01-01

    By changing the testing temperature, an austenitic Fe-Mn-Al-Si alloy presents either ε-martensite transformation or mechanical twinning during straining. In order to understand the nucleation and growth mechanisms involved in both phenomena, defects and particularly stacking faults, were characterized by transmission electron microscopy. It is observed that the character of the stacking faults also changes (from extrinsic to intrinsic) together with the temperature and the activated mode of plasticity.

  10. Teacher feedback during active learning: current practices in primary schools.

    Science.gov (United States)

    van den Bergh, Linda; Ros, Anje; Beijaard, Douwe

    2013-06-01

    Feedback is one of the most powerful tools, which teachers can use to enhance student learning. It appears difficult for teachers to give qualitatively good feedback, especially during active learning. In this context, teachers should provide facilitative feedback that is focused on the development of meta-cognition and social learning. The purpose of the present study is to contribute to the existing knowledge about feedback and to give directions to improve teacher feedback in the context of active learning. The participants comprised 32 teachers who practiced active learning in the domain of environmental studies in the sixth, seventh, or eighth grade of 13 Dutch primary schools. A total of 1,465 teacher-student interactions were examined. Video observations were made of active learning lessons in the domain of environmental studies. A category system was developed based on the literature and empirical data. Teacher-student interactions were assessed using this system. Results. About half of the teacher-student interactions contained feedback. This feedback was usually focused on the tasks that were being performed by the students and on the ways in which these tasks were processed. Only 5% of the feedback was explicitly related to a learning goal. In their feedback, the teachers were directing (rather than facilitating) the learning processes. During active learning, feedback on meta-cognition and social learning is important. Feedback should be explicitly related to learning goals. In practice, these kinds of feedback appear to be scarce. Therefore, giving feedback during active learning seems to be an important topic for teachers' professional development. © 2012 The British Psychological Society.

  11. Learning To Learn: 15 Vocabulary Acquisition Activities. Tips and Hints.

    Science.gov (United States)

    Holden, William R.

    1999-01-01

    This article describes a variety of ways learners can help themselves remember new words, choosing the ones that best suit their learning styles. It is asserted that repeated exposure to new lexical items using a variety of means is the most consistent predictor of retention. The use of verbal, visual, tactile, textual, kinesthetic, and sonic…

  12. Learning Choices, Older Australians and Active Ageing

    Science.gov (United States)

    Boulton-Lewis, Gillian M.; Buys, Laurie

    2015-01-01

    This paper reports on the findings of qualitative, semistructured interviews conducted with 40 older Australian participants who either did or did not engage in organized learning. Phenomenology was used to guide the interviews and analysis to explore the lived learning experiences and perspectives of these older people. Their experiences of…

  13. Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

    Science.gov (United States)

    Sánchez, Carolina Ramírez; Taurino, Antonietta; Bozzini, Benedetto

    2016-01-01

    This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR) electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy) nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE) method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i) morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscope (AFM); (ii) local electrical conductivity, as measured by Scanning Probe Microscopy (SPM); and (iii) molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt). Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement. PMID:28042491

  14. Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

    Directory of Open Access Journals (Sweden)

    Patrizia Bocchetta

    2016-01-01

    Full Text Available This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM and Atomic Force Microscope (AFM; (ii local electrical conductivity, as measured by Scanning Probe Microscopy (SPM; and (iii molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt. Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement.

  15. Hierarchical CNFs/MnCo2O4.5 nanofibers as a highly active oxidase mimetic and its application in biosensing

    Science.gov (United States)

    Gao, Mu; Lu, Xiaofeng; Nie, Guangdi; Chi, Maoqiang; Wang, Ce

    2017-12-01

    Recently, much attention has been paid on the nanomaterial-based artificial enzymes due to their tunable catalytic activity, high stability and low cost compared to the natural enzymes. Different from the peroxidase mimics which have been studied for several decades, nanomaterials with oxidase-like property are burgeoning in the recent years. In this paper, hierarchical carbon nanofibers (CNFs)/MnCo2O4.5 nanofibers as efficient oxidase mimics are reported. The products are synthesized by an electrospinning technique and an electrochemcial deposition process in which the CNFs are used as the working electrode where MnCo2O4.5 nanosheets deposit on. The resulting binary metal oxide-based nanocomposites exhibit a good oxidase-like activity toward the oxidations of 3,3‧,5,5‧tetramethylbenzi-dine (TMB), 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) salt and o-phenylenediamine (OPD) without exogenous addition of H2O2. The system of CNFs/MnCo2O4.5-TMB can be used as a candidate to detect sulfite and ascorbic acid via a colorimetric method with a high sensitivity. This work provides the efficient utilization and potential applications of binary metal oxide-based nanocomposites with oxidase activities in biosensors and other biotechnologies.

  16. Active learning reduces annotation time for clinical concept extraction.

    Science.gov (United States)

    Kholghi, Mahnoosh; Sitbon, Laurianne; Zuccon, Guido; Nguyen, Anthony

    2017-10-01

    To investigate: (1) the annotation time savings by various active learning query strategies compared to supervised learning and a random sampling baseline, and (2) the benefits of active learning-assisted pre-annotations in accelerating the manual annotation process compared to de novo annotation. There are 73 and 120 discharge summary reports provided by Beth Israel institute in the train and test sets of the concept extraction task in the i2b2/VA 2010 challenge, respectively. The 73 reports were used in user study experiments for manual annotation. First, all sequences within the 73 reports were manually annotated from scratch. Next, active learning models were built to generate pre-annotations for the sequences selected by a query strategy. The annotation/reviewing time per sequence was recorded. The 120 test reports were used to measure the effectiveness of the active learning models. When annotating from scratch, active learning reduced the annotation time up to 35% and 28% compared to a fully supervised approach and a random sampling baseline, respectively. Reviewing active learning-assisted pre-annotations resulted in 20% further reduction of the annotation time when compared to de novo annotation. The number of concepts that require manual annotation is a good indicator of the annotation time for various active learning approaches as demonstrated by high correlation between time rate and concept annotation rate. Active learning has a key role in reducing the time required to manually annotate domain concepts from clinical free text, either when annotating from scratch or reviewing active learning-assisted pre-annotations. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. INTEGRATION OF GAMIFICATION AND ACTIVE LEARNING IN THE CLASSROOM

    Directory of Open Access Journals (Sweden)

    Sergio Zepeda-Hernández

    2016-07-01

    Full Text Available Teachers who currently use the traditional method teacher-centered learning, are having various difficulties with the new generations of students. New learning methods are required to allow students to focus more positive attitudes towards their learning. In this paper, we show how the evaluation and activities based on Active Learning and Gamification, can be an alternative to generate a more positive attitude of students and create a more friendly environment in the classroom. This research was conducted using the qualitative research and ethnographic method as technique.

  18. Active Learning of Classification Models with Likert-Scale Feedback.

    Science.gov (United States)

    Xue, Yanbing; Hauskrecht, Milos

    2017-01-01

    Annotation of classification data by humans can be a time-consuming and tedious process. Finding ways of reducing the annotation effort is critical for building the classification models in practice and for applying them to a variety of classification tasks. In this paper, we develop a new active learning framework that combines two strategies to reduce the annotation effort. First, it relies on label uncertainty information obtained from the human in terms of the Likert-scale feedback. Second, it uses active learning to annotate examples with the greatest expected change. We propose a Bayesian approach to calculate the expectation and an incremental SVM solver to reduce the time complexity of the solvers. We show the combination of our active learning strategy and the Likert-scale feedback can learn classification models more rapidly and with a smaller number of labeled instances than methods that rely on either Likert-scale labels or active learning alone.

  19. MLS student active learning within a "cloud" technology program.

    Science.gov (United States)

    Tille, Patricia M; Hall, Heather

    2011-01-01

    In November 2009, the MLS program in a large public university serving a geographically large, sparsely populated state instituted an initiative for the integration of technology enhanced teaching and learning within the curriculum. This paper is intended to provide an introduction to the system requirements and sample instructional exercises used to create an active learning technology-based classroom. Discussion includes the following: 1.) define active learning and the essential components, 2.) summarize teaching methods, technology and exercises utilized within a "cloud" technology program, 3.) describe a "cloud" enhanced classroom and programming 4.) identify active learning tools and exercises that can be implemented into laboratory science programs, and 5.) describe the evaluation and assessment of curriculum changes and student outcomes. The integration of technology in the MLS program is a continual process and is intended to provide student-driven active learning experiences.

  20. Telling Active Learning Pedagogies Apart: from theory to practice

    Directory of Open Access Journals (Sweden)

    Kelsey Hood Cattaneo

    2017-07-01

    Full Text Available Designing learning environments to incorporate active learning pedagogies is difficult as definitions are often contested and intertwined. This article seeks to determine whether classification of active learning pedagogies (i.e., project-based, problem-based, inquiry-based, case-based, and discovery-based, through theoretical and practical lenses, could function as a useful tool for researchers and practitioners in comparing pedagogies. This article classified five active learning pedagogies based on six constructivist elements. The comparison was completed through a comparative analysis and a content analysis informed by a systematic literature review. The findings were that learner-centeredness is a primary goal of all pedagogies; however, there is a strong dissonance between each pedagogy’s theoretical underpinnings and implementation realities. This dissonance complicates differentiating active learning pedagogies and classification as a comparative tool has proved to have limited usefulness.

  1. Mo, Mn and La doped TiO{sub 2}: Synthesis, characterization and photocatalytic activity for the decolourization of three different chromophoric dyes

    Energy Technology Data Exchange (ETDEWEB)

    Umar, K.; Haque, M.M. [Department of Chemistry, Aligarh Muslim University, Aligarh 202 002 (India); Muneer, M., E-mail: readermuneer@gmail.com [Department of Chemistry, Aligarh Muslim University, Aligarh 202 002 (India); Harada, T.; Matsumura, M. [Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531 (Japan)

    2013-11-25

    Highlights: •Detail study on synthesis, characterization and photocatalytic activity of doped-TiO{sub 2}. •SEM images indicates partial crystalline nature with rough surfaces. •The XRD analysis shows the partial crystalline nature and anatase phase. •The UV–Vis absorption spectra showed λ{sub max} shift towards longer wavelength. •TiO{sub 2} with dopant 0.75% (Mo), 1.0% (Mn, La) showed best photocatalytic efficiency. -- Abstract: Nanocrystalline TiO{sub 2} particles doped with different concentrations of Molybdenum (Mo), Manganese (Mn) and Lanthanum (La) (0.25–1.0%) were synthesized using sol–gel method and characterized by standard analytical techniques such as X-ray diffraction (XRD), UV–Vis spectroscopy and Scanning Electron Microscopy (SEM). The XRD analysis shows the partial crystalline nature and anatase phase. The SEM images of undoped and doped TiO{sub 2} at different magnifications also show the partial crystalline nature with rough surfaces. The photocatalytic activity of the synthesized particles (TiO{sub 2} doped with Mo, Mn and La) was tested by studying the decolourization of three different chromophoric dyes such as Acid Red 88 (azo dye), Gentian Violet (triphenylmethane dye) and Remazol Brilliant Blue R (anthraquinone dye) as a function of time on irradiation in aqueous suspension in an immersion well photochemical reactor with a 500 W halogen linear lamp in the presence of atmospheric oxygen. The results indicate that TiO{sub 2} with dopant concentration of 0.75% (Mo) and 1.0% (Mn, La) showed the highest photocatalytic activity as compared to the other dopant concentrations for the decolourization of all the dyes.

  2. Luminescent characteristic of the CsBr phosphor activated with Eu{sup 2+} and Mn{sup 2+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Téllez-Flores, E., E-mail: bluedays8i@hotmail.com [Programa de Posgrado en Ciencias (Física), Departamento de Investigación en Física, Universidad de Sonora, Rosales y Blvd. Transversal S/N, 83000 Hermosillo, Son., México (Mexico); Aceves, R., E-mail: raceves@cifus.uson.mx [Centro de Investigación en Física, Universidad de Sonora, Apartado Postal 5-88, 83190 Hermosillo, Son., México (Mexico); Pérez-Salas, R., E-mail: rperez@cifus.uson.mx [Centro de Investigación en Física, Universidad de Sonora, Apartado Postal 5-88, 83190 Hermosillo, Son., México (Mexico); Camarillo, I., E-mail: as99@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Delegación Iztapalapa, C.P. 09340 México D.F. (Mexico); Caldiño, U., E-mail: cald@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Delegación Iztapalapa, C.P. 09340 México D.F. (Mexico)

    2013-12-15

    Spectra of excitation and emission were measured at RT and 15 K in crystals quenched (Q) of CsBr:Eu{sup 2+}, CsBr:Mn{sup 2+} and CsBr:Eu{sup 2+},Mn{sup 2+}. Emission bands at 444, 480, 520 and 570 nm with different relative intensities are generated in the samples after UV excitation. The blue band at 444 nm was ascribed with unknown clusters or aggregated centers (AC) of dipoles type Eu{sup 2+}–V{sub C}{sup −} and insulated dipole centers (IDC) like Eu{sup 2+}–O{sup 2−}. The bands at 480, 520 and 570 nm were assigned to Cs{sub 4}EuBr{sub 6} nanocrystals; AC containing MnBr{sub 4}{sup 2−} units in tetrahedral symmetry and another yet unidentified AC defect, respectively. In crystals of CsBr:Eu{sup 2+},Mn{sup 2+} the excitation and emission spectra taken at 15 K show no clear evidence of an energy transfer mechanism. Instead, the results suggest that the emission is produced by direct excitation of the ions of Eu{sup 2+} and Mn{sup 2+}. Accordingly, single- or double-doped CsBr crystals may contain the same type of defects, either AC and/or IDC. -- Highlights: • The PL consists of several overlapping bands in the entire visible region. • The emission bands were ascribed to dipoles, aggregated and nanocrystals of different nature. • No clear evidence of energy transfer, meaning Eu and Mn pairs are not formed. • The material shows potential characteristics for its use as LED to white emission.

  3. The search for active learning: Lessons from a happy accident

    OpenAIRE

    Bashforth, Hedley; Parmar, Nitin R

    2010-01-01

    This article suggests that the concept of ‘active learning’ has different meanings. These meanings are created in the dynamic and variable relationships between the uses of learning technologies and approaches to pedagogy. Institutions play a key role in mediating these relationships, privileging some meanings of ‘active learning’ over others. More dialogical forms of active learning call for changes in the mediating role of the institution. This article draws on a case study of the use of El...

  4. Active learning machine learns to create new quantum experiments.

    Science.gov (United States)

    Melnikov, Alexey A; Poulsen Nautrup, Hendrik; Krenn, Mario; Dunjko, Vedran; Tiersch, Markus; Zeilinger, Anton; Briegel, Hans J

    2018-02-06

    How useful can machine learning be in a quantum laboratory? Here we raise the question of the potential of intelligent machines in the context of scientific research. A major motivation for the present work is the unknown reachability of various entanglement classes in quantum experiments. We investigate this question by using the projective simulation model, a physics-oriented approach to artificial intelligence. In our approach, the projective simulation system is challenged to design complex photonic quantum experiments that produce high-dimensional entangled multiphoton states, which are of high interest in modern quantum experiments. The artificial intelligence system learns to create a variety of entangled states and improves the efficiency of their realization. In the process, the system autonomously (re)discovers experimental techniques which are only now becoming standard in modern quantum optical experiments-a trait which was not explicitly demanded from the system but emerged through the process of learning. Such features highlight the possibility that machines could have a significantly more creative role in future research.

  5. Technology transfer and technological learning through CERN's procurement activity

    CERN Document Server

    Autio, Erkko; Hameri, Ari-Pekka; CERN. Geneva

    2003-01-01

    This report analyses the technological learning and innovation benefits derived from CERN's procurement activity during the period 1997-2001. The base population of our study, the technology-intensive suppliers to CERN, consisted of 629 companies out of 6806 companies during the same period, representing 1197 MCHF in procurement. The main findings from the study can be summarized as follows: the various learning and innovation benefits (e.g., technological learning, organizational capability development, market learning) tend to occur together. Learning and innovation benefits appear to be regulated by the quality of the supplier's relationship with CERN: the greater the amount of social capital built into the relationship, the greater the learning and innovation benefits. Regardless of relationship quality, virtually all suppliers derived significant marketing reference benefits from CERN. Many corollary benefits are associated with procurement activity. As an example, as many as 38% of the respondents devel...

  6. Applying active learning to supervised word sense disambiguation in MEDLINE

    Science.gov (United States)

    Chen, Yukun; Cao, Hongxin; Mei, Qiaozhu; Zheng, Kai; Xu, Hua

    2013-01-01

    Objectives This study was to assess whether active learning strategies can be integrated with supervised word sense disambiguation (WSD) methods, thus reducing the number of annotated samples, while keeping or improving the quality of disambiguation models. Methods We developed support vector machine (SVM) classifiers to disambiguate 197 ambiguous terms and abbreviations in the MSH WSD collection. Three different uncertainty sampling-based active learning algorithms were implemented with the SVM classifiers and were compared with a passive learner (PL) based on random sampling. For each ambiguous term and each learning algorithm, a learning curve that plots the accuracy computed from the test set as a function of the number of annotated samples used in the model was generated. The area under the learning curve (ALC) was used as the primary metric for evaluation. Results Our experiments demonstrated that active learners (ALs) significantly outperformed the PL, showing better performance for 177 out of 197 (89.8%) WSD tasks. Further analysis showed that to achieve an average accuracy of 90%, the PL needed 38 annotated samples, while the ALs needed only 24, a 37% reduction in annotation effort. Moreover, we analyzed cases where active learning algorithms did not achieve superior performance and identified three causes: (1) poor models in the early learning stage; (2) easy WSD cases; and (3) difficult WSD cases, which provide useful insight for future improvements. Conclusions This study demonstrated that integrating active learning strategies with supervised WSD methods could effectively reduce annotation cost and improve the disambiguation models. PMID:23364851

  7. Applying active learning to supervised word sense disambiguation in MEDLINE.

    Science.gov (United States)

    Chen, Yukun; Cao, Hongxin; Mei, Qiaozhu; Zheng, Kai; Xu, Hua

    2013-01-01

    This study was to assess whether active learning strategies can be integrated with supervised word sense disambiguation (WSD) methods, thus reducing the number of annotated samples, while keeping or improving the quality of disambiguation models. We developed support vector machine (SVM) classifiers to disambiguate 197 ambiguous terms and abbreviations in the MSH WSD collection. Three different uncertainty sampling-based active learning algorithms were implemented with the SVM classifiers and were compared with a passive learner (PL) based on random sampling. For each ambiguous term and each learning algorithm, a learning curve that plots the accuracy computed from the test set as a function of the number of annotated samples used in the model was generated. The area under the learning curve (ALC) was used as the primary metric for evaluation. Our experiments demonstrated that active learners (ALs) significantly outperformed the PL, showing better performance for 177 out of 197 (89.8%) WSD tasks. Further analysis showed that to achieve an average accuracy of 90%, the PL needed 38 annotated samples, while the ALs needed only 24, a 37% reduction in annotation effort. Moreover, we analyzed cases where active learning algorithms did not achieve superior performance and identified three causes: (1) poor models in the early learning stage; (2) easy WSD cases; and (3) difficult WSD cases, which provide useful insight for future improvements. This study demonstrated that integrating active learning strategies with supervised WSD methods could effectively reduce annotation cost and improve the disambiguation models.

  8. Catalytic activity of bimetallic AuPd alloys supported MgO and MnO2 nanostructures and their role in selective aerobic oxidation of alcohols

    Directory of Open Access Journals (Sweden)

    Hamed Alshammari

    2017-10-01

    Full Text Available The use of metal oxides as supports for gold and palladium (Au-Pd nano alloys constitutes new horizons to improve catalysts materials for very important reactions. From the literatures, Pd-based bimetallic nanostructures have great properties and active catalytic performance. In this study, nanostructures of magnesium oxide (MgO and manganese dioxide (MnO₂ were synthesised and utilized as supports for Au-Pd nanoparticle catalysts. Gold and palladium were deposited on these supports using sol-immobilisation method. The MgO and MnO2 supported Au-Pd catalysts were evaluated for the oxidation of benzyl alcohol and 1-octanol, respectively. These catalysts were found to be more selective, active and reusable than the corresponding monometallic Au and Pd catalysts. The effect of base supports on the disproportionation reaction during the oxidation process was investigated. The results show that MgO stopped the disproportionation reaction for both aromatic and aliphatic alcohols while MnO₂ stopped it in the case of benzyl alcohol only. The outcomes of this work shed light on the selective aerobic oxidation of alcohols using bimetallic Au-Pd nanoalloys and pave the way to a complete investigation of more basic metal oxides for various aliphatic alcohols.

  9. Laser-Assisted Synthesis of Mn0.50Zn0.50Fe2O4 Nanomaterial: Characterization and In Vitro Inhibition Activity towards Bacillus subtilis Biofilm

    Directory of Open Access Journals (Sweden)

    Shaukat Ali Shahid

    2015-01-01

    Full Text Available There is growing interest in the development of novel nanomaterials with potential antimicrobial activity and lesser toxicity. In the current research work, Mn0.5Zn0.5Fe2O4 nanoparticles were synthesized via a novel coprecipitation cum laser ablation technique yielding fine spinal structured material. The synthesized nanomaterial was structurally characterized by X-ray diffraction technique which confirmed the formation and the crystalline nature of Mn0.50Zn0.50Fe2O4 nanomaterial. The crystallite size determined by Debye-Scherrer’s formula was found to be ~12 nm. The formation of nanoparticles was evidenced by scanning electron microscopy. Energy dispersive X-ray analysis (EDXA was performed for elemental analysis. The synthesized nanomaterial was interestingly found to be an effective antimicrobial agent and inhibited the growth of Bacillus subtilis biofilm formation. The 5 µg of Mn0.5Zn0.5Fe2O4 nanomaterial dissolved in 1 mL of DMSO showed excellent biofilm inhibitory activity 91.23% ± 1.87 against Bacillus subtilis.

  10. Moments of movement: active learning and practice development.

    Science.gov (United States)

    Dewing, Jan

    2010-01-01

    As our understanding of practice development becomes more sophisticated, we enhance our understanding of how the facilitation of learning in and from practice, can be more effectively achieved. This paper outlines an approach for enabling and maximizing learning within practice development known as 'Active Learning'. It considers how, given establishing a learning culture is a prerequisite for the sustainability of PD within organisations, practice developers can do more to maximize learning for practitioners and other stakeholders. Active Learning requires that more attention be given by organisations committed to PD, at a corporate and strategic level for how learning strategies are developed in the workplace. Specifically, a move away from a heavy reliance on training may be required. Practice development facilitators also need to review: how they organise and offer learning, so that learning strategies are consistent with the vision, aims and processes of PD; have skills in the planning, delivery and evaluation of learning as part of their role and influence others who provide more traditional methods of training and education.

  11. Active controllers and the time duration to learn a task

    Science.gov (United States)

    Repperger, D. W.; Goodyear, C.

    1986-01-01

    An active controller was used to help train naive subjects involved in a compensatory tracking task. The controller is called active in this context because it moves the subject's hand in a direction to improve tracking. It is of interest here to question whether the active controller helps the subject to learn a task more rapidly than the passive controller. Six subjects, inexperienced to compensatory tracking, were run to asymptote root mean square error tracking levels with an active controller or a passive controller. The time required to learn the task was defined several different ways. The results of the different measures of learning were examined across pools of subjects and across controllers using statistical tests. The comparison between the active controller and the passive controller as to their ability to accelerate the learning process as well as reduce levels of asymptotic tracking error is reported here.

  12. An Investigation into the Effects of Mn Promotion on the Activity and Selectivity of Co/SiO2 for Fischer - Tropsch Synthesis: Evidence for Enhanced CO Adsorption and Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gregory R.; Werner, Sebastian; Bell, Alexis T. (LBNL); (UCB)

    2016-03-04

    Mn is an effective promoter for improving the activity and selectivity of Co-based Fischer-Tropsch synthesis (FTS) catalysts, but the mechanism by which this promoter functions is poorly understood. The work reported here was aimed at defining the manner in which Mn interacts with Co and determining how these interactions affect the activity and selectivity of Co. Detailed measurements are reported for the kinetics of FTS as a function of Mn/Co ratio, temperature, and reactant partial pressure. These data are described by a single, two-parameter rate expression. Mn promotion was found to increase both the apparent rate constant for CO consumption and the CO adsorption constant. Further evidence for enhanced CO adsorption and dissociation was obtained from measurements of temperature-programmed desorption of CO and CO disproportionation rates, respectively. Our quantitative analysis of elemental maps obtained by STEM-EDS revealed that the promoter accumulates preferentially on the surface of Co nanoparticles at low Mn loadings, resulting in a rapid onset of improvements in the product selectivity as the Mn loading increases. For catalysts prepared with loadings higher than Mn/Co = 0.1, the additional Mn accumulates in the form of nanometer-scale particles of MnO on the support. In situ IR spectra of adsorbed CO show that Mn promotion increases the abundance of adsorbed CO with weakened C-O bonds. Furthermore, it is proposed that the cleavage of the C-O bond is promoted through Lewis acid-base interactions between the Mn2+ cations located at the edges of MnO islands covering the Co nanoparticles and the O atom of CO adsorbates adjacent to the MnO islands. The observed decrease in selectivity to CH4 and the increased selectivity to C5+ products with increasing Mn/Co ratio are attributed to a decrease in the ratio of adsorbed H to CO on the surface of the supported Co nanoparticles.

  13. Active Learning by Querying Informative and Representative Examples.

    Science.gov (United States)

    Huang, Sheng-Jun; Jin, Rong; Zhou, Zhi-Hua

    2014-10-01

    Active learning reduces the labeling cost by iteratively selecting the most valuable data to query their labels. It has attracted a lot of interests given the abundance of unlabeled data and the high cost of labeling. Most active learning approaches select either informative or representative unlabeled instances to query their labels, which could significantly limit their performance. Although several active learning algorithms were proposed to combine the two query selection criteria, they are usually ad hoc in finding unlabeled instances that are both informative and representative. We address this limitation by developing a principled approach, termed QUIRE, based on the min-max view of active learning. The proposed approach provides a systematic way for measuring and combining the informativeness and representativeness of an unlabeled instance. Further, by incorporating the correlation among labels, we extend the QUIRE approach to multi-label learning by actively querying instance-label pairs. Extensive experimental results show that the proposed QUIRE approach outperforms several state-of-the-art active learning approaches in both single-label and multi-label learning.

  14. Medical Student Perspectives of Active Learning: A Focus Group Study.

    Science.gov (United States)

    Walling, Anne; Istas, Kathryn; Bonaminio, Giulia A; Paolo, Anthony M; Fontes, Joseph D; Davis, Nancy; Berardo, Benito A

    2017-01-01

    Phenomenon: Medical student perspectives were sought about active learning, including concerns, challenges, perceived advantages and disadvantages, and appropriate role in the educational process. Focus groups were conducted with students from all years and campuses of a large U.S. state medical school. Students had considerable experience with active learning prior to medical school and conveyed accurate understanding of the concept and its major strategies. They appreciated the potential of active learning to deepen and broaden learning and its value for long-term professional development but had significant concerns about the efficiency of the process, the clarity of expectations provided, and the importance of receiving preparatory materials. Most significantly, active learning experiences were perceived as disconnected from grading and even as impeding preparation for school and national examinations. Insights: Medical students understand the concepts of active learning and have considerable experience in several formats prior to medical school. They are generally supportive of active learning concepts but frustrated by perceived inefficiencies and lack of contribution to the urgencies of achieving optimal grades and passing United States Medical Licensing Examinations, especially Step 1.

  15. StreamAR: incremental and active learning with evolving sensory data for activity recognition

    OpenAIRE

    Abdallah, Z.; Gaber, M.; Srinivasan, B.; Krishnaswamy, S.

    2012-01-01

    Activity recognition focuses on inferring current user activities by leveraging sensory data available on today’s sensor rich environment. Supervised learning has been applied pervasively for activity recognition. Typical activity recognition techniques process sensory data based on point-by-point approaches. In this paper, we propose a novel cluster-based classification for activity recognition Systems, termed StreamAR. The system incorporates incremental and active learning for mining user ...

  16. Enhancing learning in geosciences and water engineering via lab activities

    Science.gov (United States)

    Valyrakis, Manousos; Cheng, Ming

    2016-04-01

    This study focuses on the utilisation of lab based activities to enhance the learning experience of engineering students studying Water Engineering and Geosciences. In particular, the use of modern highly visual and tangible presentation techniques within an appropriate laboratory based space are used to introduce undergraduate students to advanced engineering concepts. A specific lab activity, namely "Flood-City", is presented as a case study to enhance the active engagement rate, improve the learning experience of the students and better achieve the intended learning objectives of the course within a broad context of the engineering and geosciences curriculum. Such activities, have been used over the last few years from the Water Engineering group @ Glasgow, with success for outreach purposes (e.g. Glasgow Science Festival and demos at the Glasgow Science Centre and Kelvingrove museum). The activity involves a specific setup of the demonstration flume in a sand-box configuration, with elements and activities designed so as to gamely the overall learning activity. Social media platforms can also be used effectively to the same goals, particularly in cases were the students already engage in these online media. To assess the effectiveness of this activity a purpose designed questionnaire is offered to the students. Specifically, the questionnaire covers several aspects that may affect student learning, performance and satisfaction, such as students' motivation, factors to effective learning (also assessed by follow-up quizzes), and methods of communication and assessment. The results, analysed to assess the effectiveness of the learning activity as the students perceive it, offer a promising potential for the use of such activities in outreach and learning.

  17. Employability and work-related learning activities in higher education

    DEFF Research Database (Denmark)

    Magnell, Marie; Kolmos, Anette

    2017-01-01

    The focus of this paper is on how academic staff perceive their roles and responsibilities regarding work-related learning, and how they approach and implement work-related learning activities in curricula across academic environments in higher education. The study is based on case studies...

  18. Resource Letter ALIP-1: Active-Learning Instruction in Physics

    Science.gov (United States)

    Meltzer, David E.; Thornton, Ronald K.

    2012-06-01

    This Resource Letter provides a guide to the literature on research-based active-learning instruction in physics. These are instructional methods that are based on, assessed by, and validated through research on the teaching and learning of physics. They involve students in their own learning more deeply and more intensely than does traditional instruction, particularly during class time. The instructional methods and supporting body of research reviewed here offer potential for significantly improved learning in comparison to traditional lecture-based methods of college and university physics instruction. We begin with an introduction to the history of active learning in physics in the United States, and then discuss some methods for and outcomes of assessing pedagogical effectiveness. We enumerate and describe common characteristics of successful active-learning instructional strategies in physics. We then discuss a range of methods for introducing active-learning instruction in physics and provide references to those methods for which there is published documentation of student learning gains.

  19. Presence in a Collaborative Science Learning Activity in Second Life

    DEFF Research Database (Denmark)

    Vrellis, Ioannis; Papachristos, Nikiforos; Natsis, Antonios

    2012-01-01

    interacting with and via virtual environments and seems to play an important role in learning. This chapter presents empirical data gathered from an exploratory study regarding a problem-based physics learning activity in Second Life (SL). Our aim is to gain knowledge and experience about the sense...

  20. An active role for machine learning in drug development

    Science.gov (United States)

    Murphy, Robert F.

    2014-01-01

    Due to the complexity of biological systems, cutting-edge machine-learning methods will be critical for future drug development. In particular, machine-vision methods to extract detailed information from imaging assays and active-learning methods to guide experimentation will be required to overcome the dimensionality problem in drug development. PMID:21587249

  1. Creating Activating Events for Transformative Learning in a Prison Classroom

    Science.gov (United States)

    Keen, Cheryl H.; Woods, Robert

    2016-01-01

    In this article, we interpreted, in light of Mezirow's theory of transformative learning, interviews with 13 educators regarding their work with marginalized adult learners in prisons in the northeastern United States. Transformative learning may have been aided by the educators' response to unplanned activating events, humor, and respect, and…

  2. Cognitive and Social Aspects of Engagement in Active Learning

    Science.gov (United States)

    Koretsky, Milo

    2017-01-01

    This article reports analysis of students' written reflections as to what helps them learn in an active learning environment. Eight hundred and twenty seven responses from 403 students in four different studio courses over two years were analyzed. An emergent coding scheme identified 55% of the responses as associated with cognitive processes…

  3. An active learning organisation: teaching projects in electrical engineering education

    NARCIS (Netherlands)

    Christensen, H.-P.; Vos, Henk; de Graaff, E.; Lemoult, B.

    2004-01-01

    The introduction of active learning in engineering education is often started by enthusiastic teachers or change agents. They usually encounter resistance from stakeholders such as colleagues, department boards or students. For a successful introduction these stakeholders all have to learn what

  4. How an Active Learning Classroom Transformed IT Executive Management

    Science.gov (United States)

    Connolly, Amy; Lampe, Michael

    2016-01-01

    This article describes how our university built a unique classroom environment specifically for active learning. This classroom changed students' experience in the undergraduate executive information technology (IT) management class. Every college graduate should learn to think critically, solve problems, and communicate solutions, but 90% of…

  5. Enhanced Memory as a Common Effect of Active Learning

    Science.gov (United States)

    Markant, Douglas B.; Ruggeri, Azzurra; Gureckis, Todd M.; Xu, Fei

    2016-01-01

    Despite widespread consensus among educators that "active learning" leads to better outcomes than comparatively passive forms of instruction, it is often unclear why these benefits arise. In this article, we review research showing that the opportunity to control the information experienced while learning leads to improved memory…

  6. Phase transition and multicolor luminescence of Eu2+/Mn2+-activated Ca3(PO4)2 phosphors

    International Nuclear Information System (INIS)

    Li, Kai; Chen, Daqin; Xu, Ju; Zhang, Rui; Yu, Yunlong; Wang, Yuansheng

    2014-01-01

    Graphical abstract: We have synthesized Eu 2+ doped and Eu 2+ /Mn 2+ co-doped Ca 3 (PO 4 ) 2 phosphors. The emitting color varies from blue to green with increasing of Eu 2+ content for the Eu 2+ -doped phosphor, and the quantum yield of the 0.05Eu 2+ : Ca 2.95 (PO 4 ) 2 sample reaches 56.7%. Interestingly, Mn 2+ co-doping into Eu 2+ : Ca 3 (PO 4 ) 2 leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu 2+ → Mn 2+ energy transfer. - Highlights: • A series of novel Eu 2+ : Ca 3 (PO 4 ) 2 phosphors were successfully synthesized. • Phase transition of Ca 3 (PO 4 ) 2 from orthorhombic to rhombohedral occurred when Mn 2+ ions were doped. • The phosphors exhibited tunable multi-color luminescence. • The quantum yield of 0.05Eu 2+ : Ca 2.95 (PO 4 ) 2 phosphor can reach 56.7%. • The analyses of phosphors were carried out by many measurements. - Abstract: Intense blue-green-emitting Eu 2+ : Ca 3 (PO 4 ) 2 and tunable multicolor-emitting Eu 2+ /Mn 2+ : Ca 3 (PO 4 ) 2 phosphors are prepared via a solid-state reaction route. Eu 2+ -doped orthorhombic Ca 3 (PO 4 ) 2 phosphor exhibits a broad emission band in the wavelength range of 400–700 nm with a maximum quantum yield of 56.7%, and the emission peak red-shifts gradually from 479 to 520 nm with increase of Eu 2+ doping content. Broad excitation spectrum (250–420 nm) of Eu 2+ : Ca 3 (PO 4 ) 2 matches well with the near-ultraviolet LED chip, indicating its potential applications as tri-color phosphors in white LEDs. Interestingly, Mn 2+ co-doping into Eu 2+ : Ca 3 (PO 4 ) 2 leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu 2+ → Mn 2+ energy transfer, under 365 nm UV lamp excitation

  7. Using assistive technology adaptations to include students with learning disabilities in cooperative learning activities.

    Science.gov (United States)

    Bryant, D P; Bryant, B R

    1998-01-01

    Cooperative learning (CL) is a common instructional arrangement that is used by classroom teachers to foster academic achievement and social acceptance of students with and without learning disabilities. Cooperative learning is appealing to classroom teachers because it can provide an opportunity for more instruction and feedback by peers than can be provided by teachers to individual students who require extra assistance. Recent studies suggest that students with LD may need adaptations during cooperative learning activities. The use of assistive technology adaptations may be necessary to help some students with LD compensate for their specific learning difficulties so that they can engage more readily in cooperative learning activities. A process for integrating technology adaptations into cooperative learning activities is discussed in terms of three components: selecting adaptations, monitoring the use of the adaptations during cooperative learning activities, and evaluating the adaptations' effectiveness. The article concludes with comments regarding barriers to and support systems for technology integration, technology and effective instructional practices, and the need to consider technology adaptations for students who have learning disabilities.

  8. Changing University Students’ Alternative Conceptions of Optics by Active Learning

    Directory of Open Access Journals (Sweden)

    Zalkida Hadžibegović

    2013-01-01

    Full Text Available Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the truly impressive implementation results of theSCALE-UP learning environment suggest that such beliefs are false (Beichner et al., 2000. In this study, we present a design of an active learning environment with positive effect on students. The design is based on the following elements: (1 helping students to learn from interactive lecture experiment; (2 guiding students to use justified explanation and prediction after observing and exploring a phenomenon; (3 developing a conceptual question sequencedesigned for use in an interactive lecture with students answering questions in worksheets by writing and drawing; (4 evaluating students’ conceptual change and gains by questions related to light reflection, refraction, and image formation in an exam held a week after the active learning session. Data were collected from 95 science freshmen with different secondary school backgrounds. They participated in geometrical optics classes organized for collecting research results during and after only one active learning session.The results have showed that around 60% of the students changed their initial alternative conceptions of vision and of image formation. It was also found that a large group of university students is likely to be engaged in active learning, shifting from a passive role they usually play during teacher’s lectures.

  9. Synthesis, spectroscopic studies and antimicrobial activity of chelates 2-(acetyloxy)-benzoic acid with transition metals (CR+3, MN+2, NI+2 AND CU+2)

    International Nuclear Information System (INIS)

    Khan, B.; Mateen, B.; Ahmed, F.; Ahmed, F.

    2007-01-01

    2-(acetyloxy)-Benzoic acid chelates with Cr+3, Mn+2, Ni+2 and Cu+2 were synthesized and characterized by the melting point, solubility, Fourier Transform Infrared (FT-IR) Spectroscopy, Atomic Absorption Spectroscopy (AAS), X-Ray Diffraction (XRD) method and evaluated by antimicrobial activity. The functional group present in the chelates was determined by Fourier Transform Infrared Spectroscopy, by X-Ray Diffraction analysis crystal data of chelates, their inter-atomic and inter-planer spacing was also determined. The amount of metal in the chelates was estimated by Atomic Absorption Spectroscopy and their Antimicrobial Activity was studied against Pseudomonas aeruginosa, Escherisha coli and Staphylococcus aureus. (author)

  10. Active Learning to Improve Fifth Grade Mathematics Achievement in Banten

    Directory of Open Access Journals (Sweden)

    Andri Suherman

    2011-12-01

    Full Text Available Teaching for active learning is a pedagogical technique that has been actively promoted in Indonesian education through government reform efforts and international development assistance projects for decades. Recently, elementary schools in Banten province received training in active learning instructional strategies from the USAID-funded project, Decentralized Basic Education 2. Post-training evaluations conducted by lecturers from the University of Sultan Ageng Tirtayasa (UNTIRTA: Universitas Sultan Ageng Tirtayasa suggested that teachers were successfully employing active learning strategies in some subjects, but not mathematics. In order to understand the difficulties teachers were having in teaching for active learning in mathematics, and to assist them in using active learning strategies, a team of lecturers from UNTIRTA designed and carried out an action research project to train teachers in an elementary school in the city of Cilegon to use a technique called Magic Fingers in teaching Grade 5 multiplication. During the course of the project the research team discovered that teachers were having problems transferring knowledge gained from training in one context and subject to other school subjects and contexts. Key Words: Mathematics, Teaching for Active Learning, Indonesia, Banten

  11. Developing capability through peer-assisted learning activities ...

    African Journals Online (AJOL)

    L-CAS) is an activity by means of which each student is exposed to primary healthcare learning and practice in communities. Capability has been described as 'an integration of knowledge, skills, personal qualities and understanding used ...

  12. Physical Activity and Wellness: Applied Learning through Collaboration

    Science.gov (United States)

    Long, Lynn Hunt; Franzidis, Alexia

    2015-01-01

    This article describes how two university professors teamed up to initiate a university-sponsored physical activity and wellness expo in an effort to promote an authentic and transformative learning experience for preservice students.

  13. Teachers' Perceptions and Practices of Active Learning in ...

    African Journals Online (AJOL)

    Teachers' Perceptions and Practices of Active Learning in Haramaya ... Science, Technology and Arts Research Journal ... traditional/lecture method, lack of students' interest, shortage of time, lack of instructional material and large class size.

  14. Prototype-based active learning for lemmatization

    CSIR Research Space (South Africa)

    Daelemans, W

    2009-09-01

    Full Text Available ] and Word Length [Long to Short] with the prototypical curves (e.g. Word Frequency [High to Low] and [Word Length Short to Long]). (With regard to the learning curves representing word frequency, refer to 4.1 for an explanation of why [High to Low... of language usage [15]. Secondly, in memory-based language processing [16] it has been argued, on the basis of com- parative machine learning experiments on natural lan- guage processing data, that exceptions are crucial for obtaining high generalization...

  15. CNT supported Mn-doped ZnO nanoparticles: simple synthesis and improved photocatalytic activity for degradation of malachite green dye under visible light

    Science.gov (United States)

    Mohamed, R. M.; Shawky, Ahmed

    2018-03-01

    Hexagonal ZnO nanoparticles doped with Mn and supported with a minor amount of carbon nanotubes (CNTs) were synthesized through a simple coprecipitation-ultrasonication process with high yield. The effect of Mn doping, as well as CNTs addition on structure, surface morphology and texture, optical and electronic properties, was studied. We found that just 1% Mn doping and 1% CNT addition on ZnO showed the best crystallinity, highest surface area, improved visible light absorption, and a lowest estimated band gap of 2.6 eV with minimum charge recombination as revealed from photoluminescence spectra. The application of the optimum composition of the synthesized sample for the photodegradation of malachite green dye showed enhanced photocatalytic activity > 95% under visible light irradiation within 120 min at a minimum dosage of 0.1 g L-1 without any using of hole scavenger or changing the pH. This work highlighting the humble preparation procedure and develops photocatalysis research for real industrial applications.

  16. Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

    Directory of Open Access Journals (Sweden)

    Monika Tyagi

    2014-01-01

    Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

  17. Localization-Aware Active Learning for Object Detection

    OpenAIRE

    Kao, Chieh-Chi; Lee, Teng-Yok; Sen, Pradeep; Liu, Ming-Yu

    2018-01-01

    Active learning - a class of algorithms that iteratively searches for the most informative samples to include in a training dataset - has been shown to be effective at annotating data for image classification. However, the use of active learning for object detection is still largely unexplored as determining informativeness of an object-location hypothesis is more difficult. In this paper, we address this issue and present two metrics for measuring the informativeness of an object hypothesis,...

  18. Learning Microbiology Through Cooperation: Designing Cooperative Learning Activities that Promote Interdependence, Interaction, and Accountability

    Directory of Open Access Journals (Sweden)

    Janine E. Trempy

    2009-12-01

    Full Text Available A microbiology course and its corresponding learning activities have been structured according to the Cooperative Learning Model. This course, The World According to Microbes, integrates science, math, engineering, and technology (SMET majors and non-SMET majors into teams of students charged with problem solving activities that are microbial in origin. In this study we describe development of learning activities that utilize key components of Cooperative Learning—positive interdependence, promotive interaction, individual accountability, teamwork skills, and group processing. Assessments and evaluations over an 8-year period demonstrate high retention of key concepts in microbiology and high student satisfaction with the course.

  19. Measurement of carbon activity in sodium by Fe-Mn 20% alloy, and by strainless austenitic steel 304L and 316L

    International Nuclear Information System (INIS)

    Oberlin, C.; Saint Paul, P.; Baque, P.; Champeix, L.

    1980-01-01

    Precise knowledge of carbon activity in sodium used as coolant in fast breeder reactors, is essential for continuous survey of carburization-decarburization processes. Carbon activity can be periodically surveyed by measuring the carbon concentration or by hot trap like metal alloy strip placed in sodium loop. In fact, in equilibrium, activity of carbon in sodium is equal to the activity in metal alloy. Thus if the relation between concentration of carbon and it activity in the alloy is known, it is possible to estimate the activity of carbon in sodium. Materials to be used should have high solubility in carbon at the needed temperature. They should quickly attain equilibrium with sodium and they should not contain impurities that can affect the results. Materials chosen according to these criteria were Fe-Mn 20%, stainless austenitic steel AISI 304L and 316L

  20. Active Reading Behaviors in Tablet-Based Learning

    Science.gov (United States)

    Palilonis, Jennifer; Bolchini, Davide

    2015-01-01

    Active reading is fundamental to learning. However, there is little understanding about whether traditional active reading frameworks sufficiently characterize how learners study multimedia tablet textbooks. This paper explores the nature of active reading in the tablet environment through a qualitative study that engaged 30 students in an active…

  1. Active Learning: 101 Strategies To Teach Any Subject.

    Science.gov (United States)

    Silberman, Mel

    This book contains specific, practical strategies that can be used for almost any subject matters to promote active learning. It brings together in one source a comprehensive collection of instructional strategies, with ways to get students to be active from the beginning through activities that build teamwork and get students thinking about the…

  2. Visible light activity of pulsed layer deposited BiVO{sub 4}/MnO{sub 2} films decorated with gold nanoparticles: The evidence for hydroxyl radicals formation

    Energy Technology Data Exchange (ETDEWEB)

    Trzciński, Konrad, E-mail: trzcinskikonrad@gmail.com [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Szkoda, Mariusz [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Sawczak, Mirosław [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid Flow Machinery, Fiszera 14, 80-231 Gdansk (Poland); Karczewski, Jakub [Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Lisowska-Oleksiak, Anna [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland)

    2016-11-01

    Highlights: • The BiVO{sub 4} + MnO{sub 2} photoactive layers were prepared by pulsed laser deposition method. • Prepared layers can act as photoanodes for water splitting. • The thin BiVO{sub 4} + MnO{sub 2} film can be used as photocatalyst for methylene blue degradation. • The formation of hydroxyl radicals during photocatalys illumination has been proved. • The dropcasted GNP improved significantly photocatalytic properties of tested layers. - Abstract: Thin films containing BiVO{sub 4} and MnO{sub 2} deposited on FTO and modified by Au nanoparticles were studied towards their photoelectrochemical and photocatalytical activities in an aqueous electrolyte. Electrodes were prepared by the pulsed laser deposition (PLD) method. The surfactant-free ablation process was used for preparation of the gold nanoparticles (GNP) water suspension. Obtained layers of varied thicknesses (27–115 nm) were characterized using Raman spectroscopy, UV–vis spectroscopy and scanning electron microscopy. Electrochemical methods such as electrochemical impedance spectroscopy, linear voltammetry and chronoamperometry under visible light illumination and in the dark were applied to characterize layers as photoanodes. Simple modification of the BiVO{sub 4} + MnO{sub 2} layer by drop-casting of small amount of colloidal gold (1.5 × 10{sup −14} mol of GNP on 1 cm{sup 2}) leads to enhancement of the generated photocurrent recorded at E = 0.5 V vs. Ag/AgCl (0.1 M KCl) from 63 μA/cm{sup 2} to 280 μA/cm{sup 2}. Photocatalytical studies were also exploited towards decomposition of methylene blue (MB). A possible mechanism of MB photodegradation was proposed. The formation of hydroxyl radicals was detected by photoluminescence spectra using terephthalic acid as the probe molecule.

  3. Total Diet Study. Mg and Mn content estimation of a Market Basket of Sao Paulo state (Brazil) by Instrumental Neutron Activation

    International Nuclear Information System (INIS)

    Roseane Pagliaro Avegliano; Vera Akiko Maihara

    2014-01-01

    Total Diet Studies (TDS) have been carried out to estimate dietary intakes of the essential and toxic elements for a large-scale population over a specific period of time. In this study, the TDS was based on the evaluation of food representing a Market Basket (MB), which reflected the dietary habits of the Sao Paulo State population, corresponding to 72 % of the average food consumption for the state of Sao Paulo. In the present Total Diet Study, magnesium and manganese concentrations were determined in 30 of the most consumed food groups of a MB of Sao Paulo State, Brazil. Instrumental Neutron Activation Analysis (INAA) has been successfully used on a regularly basis in several areas of nutrition and foodstuffs. Element concentrations were determined by INAA in freeze-dried samples and ranged in mg kg -1 . Mg 41.4 (fats)-5287 (coffee) and Mn 0.12 (prime grade beef)-32.9 (coffee). The average daily Mg and Mn intake was calculated by multiplying the concentration of each element in each table-ready food group by the respective weight (g day -1 ) of the food group in the MB and adding the products from all food groups. The results of daily dietary intakes in this study were: Mg 174.8 and Mn 1.34 mg day -1 . Theses values were lower than the adequate intake (AI) proposed by the Food and Nutrition Board of the Institute of Medicine (USA National Academy) for adults. The low levels of Mg and Mn intakes presented in this TDS are probably due to the fact that MB of this study represented only 72 % of the weight of the most consumed household foods of Sao Paulo State. (author)

  4. Active Learning of Markov Decision Processes for System Verification

    DEFF Research Database (Denmark)

    Chen, Yingke; Nielsen, Thomas Dyhre

    2012-01-01

    deterministic Markov decision processes from data by actively guiding the selection of input actions. The algorithm is empirically analyzed by learning system models of slot machines, and it is demonstrated that the proposed active learning procedure can significantly reduce the amount of data required...... demanding process, and this shortcoming has motivated the development of algorithms for automatically learning system models from observed system behaviors. Recently, algorithms have been proposed for learning Markov decision process representations of reactive systems based on alternating sequences...... of input/output observations. While alleviating the problem of manually constructing a system model, the collection/generation of observed system behaviors can also prove demanding. Consequently we seek to minimize the amount of data required. In this paper we propose an algorithm for learning...

  5. [Supporting an Academic Society with the Active Learning Tool Clica].

    Science.gov (United States)

    Arai, Kensuke; Mitsubori, Masahiro

    2018-01-01

     Within school classrooms, Active Learning has been receiving unprecedented attention. Indeed, Active Learning's popularity does not stop in the classroom. As more and more people argue that the Japanese government needs to renew guidelines for education, Active Learning has surfaced as a method capable of providing the necessary knowledge and training for people in all areas of society, helping them reach their full potential. It has become accepted that Active Learning is more effective over the passive listening of lectures, where there is little to no interaction. Active Learning emphasizes that learners explain their thoughts, ask questions, and express their opinions, resulting in a better retention rate of the subject at hand. In this review, I introduce an Active Learning support tool developed at Digital Knowledge, "Clica". This tool is currently being used at many educational institutions. I will also introduce an online questionnaire that Digital Knowledge provided at the 10th Annual Meeting of the Japanese Society for Pharmaceutical Palliative Care and Sciences.

  6. Integrative Student Learning: An Effective Team Learning Activity in a Learner-Centered Paradigm

    Directory of Open Access Journals (Sweden)

    Reza Karimi, RPh, PhD

    2011-01-01

    Full Text Available Purpose: An Integrative Student Learning (ISL activity was developed with the intent to enhance the dynamic of student teamwork and enhance student learning by fostering critical-thinking skills, self-directed learning skills, and active learning. Case Study: The ISL activity consists of three portions: teambuilding, teamwork, and a facilitator driven “closing the loop” feedback discussion. For teambuilding, a set of clue sheets or manufacturer‘s drug containers were distributed among student pairs who applied their pharmaceutical knowledge to identify two more student pairs with similar clues or drugs, thus building a team of six. For teamwork, each team completed online exams, composed of integrated pharmaceutical science questions with clinical correlates, using only selected online library resources. For the feedback discussion, facilitators evaluated student impressions, opened a discussion about the ISL activity, and provided feedback to teams’ impressions and questions. This study describes three different ISL activities developed and implemented over three days with first year pharmacy students. Facilitators’ interactions with students and three surveys indicated a majority of students preferred ISL over traditional team activities and over 90% agreed ISL activities promoted active learning, critical-thinking, self-directed learning, teamwork, and student confidence in online library searches. Conclusions: The ISL activity has proven to be an effective learning activity that promotes teamwork and integration of didactic pharmaceutical sciences to enhance student learning of didactic materials and confidence in searching online library resources. It was found that all of this can be accomplished in a short amount of class time with a very reasonable amount of preparation.

  7. Integrative Student Learning: An Effective Team Learning Activity in a Learner-Centered Paradigm

    Directory of Open Access Journals (Sweden)

    Reza Karimi

    2011-01-01

    Full Text Available Purpose: An Integrative Student Learning (ISL activity was developed with the intent to enhance the dynamic of student teamwork and enhance student learning by fostering critical-thinking skills, self-directed learning skills, and active learning. Case Study: The ISL activity consists of three portions: teambuilding, teamwork, and a facilitator driven "closing the loop" feedback discussion. For teambuilding, a set of clue sheets or manufacturer's drug containers were distributed among student pairs who applied their pharmaceutical knowledge to identify two more student pairs with similar clues or drugs, thus building a team of six. For teamwork, each team completed online exams, composed of integrated pharmaceutical science questions with clinical correlates, using only selected online library resources. For the feedback discussion, facilitators evaluated student impressions, opened a discussion about the ISL activity, and provided feedback to teams' impressions and questions. This study describes three different ISL activities developed and implemented over three days with first year pharmacy students. Facilitators' interactions with students and three surveys indicated a majority of students preferred ISL over traditional team activities and over 90% agreed ISL activities promoted active learning, critical-thinking, self-directed learning, teamwork, and student confidence in online library searches. Conclusions: The ISL activity has proven to be an effective learning activity that promotes teamwork and integration of didactic pharmaceutical sciences to enhance student learning of didactic materials and confidence in searching online library resources. It was found that all of this can be accomplished in a short amount of class time with a very reasonable amount of preparation.   Type: Case Study

  8. Active Multi-Field Learning for Spam Filtering

    OpenAIRE

    Wuying Liu; Lin Wang; Mianzhu Yi; Nan Xie

    2015-01-01

    Ubiquitous spam messages cause a serious waste of time and resources. This paper addresses the practical spam filtering problem, and proposes a universal approach to fight with various spam messages. The proposed active multi-field learning approach is based on: 1) It is cost-sensitive to obtain a label for a real-world spam filter, which suggests an active learning idea; and 2) Different messages often have a similar multi-field text structure, which suggests a multi-field learning idea. The...

  9. Implementation of Active Learning Method in Unit Operations II Subject

    OpenAIRE

    Ma'mun, Sholeh

    2018-01-01

    ABSTRACT: Active Learning Method which requires students to take an active role in the process of learning in the classroom has been applied in Department of Chemical Engineering, Faculty of Industrial Technology, Islamic University of Indonesia for Unit Operations II subject in the Even Semester of Academic Year 2015/2016. The purpose of implementation of the learning method is to assist students in achieving competencies associated with the Unit Operations II subject and to help in creating...

  10. R and D of low activated Fe-Mn-Cr high strength non-magnetic steel, (I). Screening test for constituent optimization and fundamental characterization test

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, Shintaro; Fukaya, Kiyoshi; Eto, Motokuni; Kikuchi, Mituru [Japan Atomic Energy Research Inst., Tokyo (Japan); Sato, Ikuo; Kusuhashi, Mikio; Hatakeyama, Tuyoshi [Japan Steel Works Ltd., Tokyo (Japan); Takahashi, Heishitiro [Center for Advanced Research of Energy Technology, Hokkaido Univ., Sapporo (Japan)

    2000-02-01

    It is very important to develop low activated/non-magnetic materials as large scale structural materials for fusion reactors. In the structural design of JT-60SU, low activated/non-magnetic materials with high specific strength and low decay heat characterizations are required. In the present paper, a new low activated/non-magnetic material (15.5 Mn-16Cr-0.2N-0.3Si-0.2C (wt%)) based on the conventional high manganese steel with lower Ni, CO, C, N and Mn contents for the purpose of lower activation and decay heat was developed and the mass production conditions of the material were optimized. Fundamental material characterization tests of the new material developed in present study were carried out, and the following conclusions are derived ; (1) Lower activation characterizations with the new materials in the order of 1/10 of that of SUS316L steel, (2) Higher strength of the material in the order of 2{approx}3 of SUS316L steel and (3) Lower decay heat with higher thermal conductivity with comparison of SUS316L steel. (author)

  11. Collaborative learning in higher education : design, implementation and evaluation of group learning activities

    NARCIS (Netherlands)

    Hei, de M.S.A.

    2016-01-01

    In higher education, group learning activities (GLAs) are frequently implemented in online, blended or face-to-face educational contexts. A major problem for the design and implementation of good quality GLAs that lead to the desired learning outcomes is that many approaches to GLAs have been

  12. Learning Active Citizenship: Conflicts between Students' Conceptualisations of Citizenship and Classroom Learning Experiences in Lebanon

    Science.gov (United States)

    Akar, Bassel

    2016-01-01

    Education for active citizenship continues to be a critical response for social cohesion and reconstruction in conflict-affected areas. Oftentimes, approaches to learning and teaching in such contexts can do as much harm as good. This study qualitatively examines 435 students' reflections of their civics classroom learning experiences and their…

  13. Student's Reflections on Their Learning and Note-Taking Activities in a Blended Learning Course

    Science.gov (United States)

    Nakayama, Minoru; Mutsuura, Kouichi; Yamamoto, Hiroh

    2016-01-01

    Student's emotional aspects are often discussed in order to promote better learning activity in blended learning courses. To observe these factors, course participant's self-efficacy and reflections upon their studies were surveyed, in addition to the surveying of the metrics of student's characteristics during a Bachelor level credit course.…

  14. Learning by Doing: Twenty Successful Active Learning Exercises for Information Systems Courses

    Science.gov (United States)

    Mitchell, Alanah; Petter, Stacie; Harris, Albert L.

    2017-01-01

    Aim/Purpose: This paper provides a review of previously published work related to active learning in information systems (IS) courses. Background: There are a rising number of strategies in higher education that offer promise in regards to getting students' attention and helping them learn, such as flipped classrooms and offering courses online.…

  15. Active-constructive-interactive: a conceptual framework for differentiating learning activities.

    Science.gov (United States)

    Chi, Michelene T H

    2009-01-01

    Active, constructive, and interactive are terms that are commonly used in the cognitive and learning sciences. They describe activities that can be undertaken by learners. However, the literature is actually not explicit about how these terms can be defined; whether they are distinct; and whether they refer to overt manifestations, learning processes, or learning outcomes. Thus, a framework is provided here that offers a way to differentiate active, constructive, and interactive in terms of observable overt activities and underlying learning processes. The framework generates a testable hypothesis for learning: that interactive activities are most likely to be better than constructive activities, which in turn might be better than active activities, which are better than being passive. Studies from the literature are cited to provide evidence in support of this hypothesis. Moreover, postulating underlying learning processes allows us to interpret evidence in the literature more accurately. Specifying distinct overt activities for active, constructive, and interactive also offers suggestions for how learning activities can be coded and how each kind of activity might be elicited. Copyright © 2009 Cognitive Science Society, Inc.

  16. Active learning increases student performance in science, engineering, and mathematics.

    Science.gov (United States)

    Freeman, Scott; Eddy, Sarah L; McDonough, Miles; Smith, Michelle K; Okoroafor, Nnadozie; Jordt, Hannah; Wenderoth, Mary Pat

    2014-06-10

    To test the hypothesis that lecturing maximizes learning and course performance, we metaanalyzed 225 studies that reported data on examination scores or failure rates when comparing student performance in undergraduate science, technology, engineering, and mathematics (STEM) courses under traditional lecturing versus active learning. The effect sizes indicate that on average, student performance on examinations and concept inventories increased by 0.47 SDs under active learning (n = 158 studies), and that the odds ratio for failing was 1.95 under traditional lecturing (n = 67 studies). These results indicate that average examination scores improved by about 6% in active learning sections, and that students in classes with traditional lecturing were 1.5 times more likely to fail than were students in classes with active learning. Heterogeneity analyses indicated that both results hold across the STEM disciplines, that active learning increases scores on concept inventories more than on course examinations, and that active learning appears effective across all class sizes--although the greatest effects are in small (n ≤ 50) classes. Trim and fill analyses and fail-safe n calculations suggest that the results are not due to publication bias. The results also appear robust to variation in the methodological rigor of the included studies, based on the quality of controls over student quality and instructor identity. This is the largest and most comprehensive metaanalysis of undergraduate STEM education published to date. The results raise questions about the continued use of traditional lecturing as a control in research studies, and support active learning as the preferred, empirically validated teaching practice in regular classrooms.

  17. Competency and an active learning program in undergraduate nursing education.

    Science.gov (United States)

    Shin, Hyunsook; Sok, Sohyune; Hyun, Kyung Sun; Kim, Mi Ja

    2015-03-01

    To evaluate the effect of an active learning program on competency of senior students. Active learning strategies have been used to help students achieve desired nursing competency, but their effectiveness has not been systematically examined. A descriptive, cross-sectional comparative design was used. Two cohort group comparisons using t-test were made: one in an active learning group and the other in a traditional learning group. A total of 147 senior nursing students near graduation participated in this study: 73 in 2010 and 74 in 2013. The active learning program incorporated high-fidelity simulation, situation-based case studies, standardized patients, audio-video playback, reflective activities and technology such as a SmartPad-based program. The overall scores of the nursing competency in the active group were significantly higher than those in the traditional group. Of five overall subdomains, the scores of the special and general clinical performance competency, critical thinking and human understanding were significantly higher in the active group than in the traditional group. Importance-performance analysis showed that all five subdomains of the active group clustered in the high importance and high performance quadrant, indicating significantly better achievements. In contrast, the students in the traditional group showed scattered patterns in three quadrants, excluding the low importance and low performance quadrants. This pattern indicates that the traditional learning method did not yield the high performance in most important areas. The findings of this study suggest that an active learning strategy is useful for helping undergraduate students to gain competency. © 2014 John Wiley & Sons Ltd.

  18. Effectiveness of Student's Note-Taking Activities and Characteristics of Their Learning Performance in Two Types of Online Learning

    Science.gov (United States)

    Nakayama, Minoru; Mutsuura, Kouichi; Yamamoto, Hiroh

    2017-01-01

    Aspects of learning behavior during two types of university courses, a blended learning course and a fully online course, were examined using note-taking activity. The contribution of students' characteristics and styles of learning to note-taking activity and learning performance were analyzed, and the relationships between the two types of…

  19. The planning illusion: Does active planning of a learning route support learning as well as learners think it does?

    NARCIS (Netherlands)

    Bonestroo, W.J.; de Jong, Anthonius J.M.

    2012-01-01

    Is actively planning one’s learning route through a learning domain beneficial for learning? Moreover, can learners accurately judge the extent to which planning has been beneficial for them? This study examined the effects of active planning on learning. Participants received a tool in which they

  20. Active Learning Classrooms and Educational Alliances: Changing Relationships to Improve Learning

    Science.gov (United States)

    Baepler, Paul; Walker, J. D.

    2014-01-01

    This chapter explores the "educational alliance" among students and between students and instructors. We contend that this is a framework that can help us understand how active learning classrooms facilitate positive educational outcomes.

  1. Research and Teaching: Instructor Use of Group Active Learning in an Introductory Biology Sequence

    Science.gov (United States)

    Auerbach, Anna Jo; Schussler, Elisabeth E.

    2016-01-01

    Active learning (or learner-centered) pedagogies have been shown to enhance student learning in introductory biology courses. Student collaboration has also been shown to enhance student learning and may be a critical part of effective active learning practices. This study focused on documenting the use of individual active learning and group…

  2. Active Learning: Qualitative Inquiries into Vocabulary Instruction in Chinese L2 Classrooms

    Science.gov (United States)

    Shen, Helen H.; Xu, Wenjing

    2015-01-01

    Active learning emerged as a new approach to learning in the 1980s. The core concept of active learning involves engaging students not only in actively exploring knowledge but also in reflecting on their own learning process in order to become more effective learners. Because the nonalphabetic nature of the Chinese writing system makes learning to…

  3. Modulation of the Activities of Catalase, Cu-Zn, Mn Superoxide Dismutase, and Glutathione Peroxidase in Adipocyte from Ovariectomised Female Rats with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Rebeca Cambray Guerra

    2014-01-01

    Full Text Available The aim of this study was to evaluate the association between estrogen removal, antioxidant enzymes, and oxidative stress generated by obesity in a MS female rat model. Thirty two female Wistar rats were divided into 4 groups: Control (C, MS, MS ovariectomized (Ovx, and MS Ovx plus estradiol (E2. MS was induced by administering 30% sucrose to drinking water for 24 weeks. After sacrifice, intra-abdominal fat was dissected; adipocytes were isolated and lipid peroxidation, non-enzymatic antioxidant capacity, and the activities of Cu-Zn and Mn superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GPx were determined. There were no significant differences in the activities of Cu-Zn, Mn SOD, CAT, and GPx between the C and MS groups, but in the MS Ovx group there was a statistically significant decrease in the activities of these enzymes when compared to MS and MS Ovx+E2. The increased lipid peroxidation and nonenzymatic antioxidant capacity found in MS Ovx was significantly decreased when compared to MS and MS Ovx+E2. In conclusion, the removal of E2 by ovariectomy decreases the activity of the antioxidant enzymes in the intra-abdominal tissue of MS female rats; this is reflected by increased lipid peroxidation and decreased nonenzymatic antioxidant capacity.

  4. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

    Science.gov (United States)

    Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly…

  5. A Nap But Not Rest or Activity Consolidates Language Learning

    Directory of Open Access Journals (Sweden)

    Stefan Heim

    2017-05-01

    Full Text Available Recent evidence suggests that a period of sleep after a motor learning task is a relevant factor for memory consolidation. However, it is yet open whether this also holds true for language-related learning. Therefore, the present study compared the short- and long-term effects of a daytime nap, rest, or an activity task after vocabulary learning on learning outcome. Thirty healthy subjects were divided into three treatment groups. Each group received a pseudo-word learning task in which pictures of monsters were associated with unique pseudo-word names. At the end of the learning block a first test was administered. Then, one group went for a 90-min nap, one for a waking rest period, and one for a resting session with interfering activity at the end during which a new set of monster names was to be learned. After this block, all groups performed a first re-test of the names that they initially learned. On the morning of the following day, a second re-test was administered to all groups. The nap group showed significant improvement from test to re-test and a stable performance onto the second re-test. In contrast, the rest and the interference groups showed decline in performance from test to re-test, with persistently low performance at re-test 2. The 3 (GROUP × 3 (TIME ANOVA revealed a significant interaction, indicating that the type of activity (nap/rest/interfering action after initial learning actually had an influence on the memory outcome. These data are discussed with respect to translation to clinical settings with suggestions for improvement of intervention outcome after speech-language therapy if it is followed by a nap rather than interfering activity.

  6. The Managers’ Experiential Learning of Program Planning in Active Ageing Learning Centers

    Directory of Open Access Journals (Sweden)

    Chun-Ting Yeh

    2016-12-01

    Full Text Available Planning older adult learning programs is really a complex work. Program planners go through different learning stages and accumulate experiences to be able to undertake the task alone. This study aimed to explore the experiential learning process of older adult learning program planners who work in the Active Ageing Learning Centers (AALCs. Semi-structure interviews were conducted with seven program planners. The findings of this study were identified as follows. 1 Before being a program planner, the participants’ knowledge results from grasping and transforming experience gained from their family, their daily lives and past learning experiences; 2 after being a program planner, the participants’ experiential learning focused on leadership, training in the institute, professional development, as well as involvement in organizations for elderly people; and 3 the participants’ experiential learning outcomes in the older adult learning program planning include: their ability to reflect on the appropriateness and fulfillment of program planning, to apply theoretical knowledge and professional background in the field, and to make plans for future learning and business strategies.

  7. Active Learning Innovations in Knowledge Management Education Generate Higher Quality Learning Outcomes

    Directory of Open Access Journals (Sweden)

    Arthur Shelley

    2014-01-01

    Full Text Available Innovations in how a postgraduate course in knowledge management is delivered have generated better learning outcomes and made the course more engaging for learners. Course participant feedback has shown that collaborative active learning is preferred and provides them with richer insights into how knowledge is created and applied to generate innovation and value. The course applies an andragogy approach in which students collaborate in weekly dialogue of their experiences of the content, rather than learn the content itself. The approach combines systems thinking, learning praxis, and active learning to explore the interdependencies between topics and how they impact outcomes in real world situations. This has stimulated students to apply these ideas in their own workplaces.

  8. Synthesis, magnetization and photocatalytic activity of LaFeO{sub 3} and LaFe{sub 0.5}Mn{sub 0.5-x}O{sub 3-{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Zhi-Xian, E-mail: zx_wei@126.com [Beijing Institute of Protective Materials and Technology, Beijing 100081 (China); School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Department of Chemistry, Science Institute, North University of China, Taiyuan, Shanxi 030051 (China); Wang, Yan [Department of Chemistry, Chengde Teachers College for Nationalities, Chengde, Hebei 067000 (China); Liu, Ji-Ping, E-mail: liujp@bit.edu.cn [Beijing Institute of Protective Materials and Technology, Beijing 100081 (China); School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Xiao, Cai-Mei; Zeng, Wei-Wei [Department of Chemistry, Science Institute, North University of China, Taiyuan, Shanxi 030051 (China)

    2012-10-15

    Perovskite LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} and LaFeO{sub 3} were synthesized by stearic acid solution combustion method. The obtained powders were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Vibrating sample magnetometer (VSM), XPS techniques and UV-vis absorption spectra techniques. The magnetic properties of the LaFeO{sub 3} and LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were measured, and they were also evaluated for their photocatalytic activity towards the degradation of methyl orange (MO) under the sunlight irradiation. The experimental results show that the catalytic activities of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were much higher than those of LaFeO{sub 3} due to its higher oxygen vacancies, variable valency Mn ions and the strong absorption in visible light. The optimum conditions for photocatalytic degradation MO using LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were achieved. The ferromagnetism of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} could be caused by the Mn{sup 3+}/Fe{sup 3+} and Mn{sup 3+}/Mn{sup 4+}double exchange interaction, Mn{sup 3+}/Mn{sup 3+} superexchange interactions as well as the defective state in LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}}. The LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is applicable to the magnetic separation process for its lower coercivity (Hc) and remanent magnetization (Mr), and it can be reusable and maintain relatively high activity. -- Highlights: Black-Right-Pointing-Pointer The LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is a bifunctional photocatalyst. Black-Right-Pointing-Pointer The origin of the ferromagnetism of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is discussed. Black-Right-Pointing-Pointer LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} shows much higher photocatalytic activity than that of LaFeO{sub 3.} Black-Right-Pointing-Pointer LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} can be recycled by an external magnetic

  9. Determination of photo-catalytic activity of un-doped and Mn-doped TiO2 anatase powders on acetaldehyde under UV and visible light

    International Nuclear Information System (INIS)

    Papadimitriou, Vassileios C.; Stefanopoulos, Vassileios G.; Romanias, Manolis N.; Papagiannakopoulos, Panos; Sambani, Kyriaki; Tudose, Valentin; Kiriakidis, George

    2011-01-01

    Titanium dioxide (TiO 2 ) photocatalytic powder materials doped with various levels of manganese (Mn) were synthesized to be used as additives to wall painting in combating indoor and outdoor air pollution. The heterogeneous photocatalytic degradation of gaseous acetaldehyde (CH 3 CHO) on Mn–TiO 2 surfaces under ultraviolet and visible (UV/Vis) irradiation was investigated, by employing the Photochemical Static Reactor coupled with Fourier-Transformed Infrared spectroscopy (PSR/FTIR) technique. Experiments were performed by exposing acetaldehyde (∼ 400 Pa) and synthetic air mixtures (∼ 1.01 × 10 5 Pa total pressure) on un-doped TiO 2 and doped with various levels of Mn (0.1–33% mole percentage) under UV and visible irradiation at room temperature. Photoactivation was initiated using either UV or visible light sources with known emission spectra. Initially, the photo-activity of CH 3 CHO under the above light sources, and the physical adsorption of CH 3 CHO on Mn–TiO 2 samples in the absence of light were determined prior to the photocatalytic experiments. The photocatalytic loss of CH 3 CHO on un-doped TiO 2 and Mn–TiO 2 samples in the absence and presence of UV or visible irradiation was measured over a long time period (≈ 60 min), to evaluate their relative photocatalytic activity. The gaseous photocatalytic end products were also determined using absorption FTIR spectroscopy. Carbon dioxide (CO 2 ) was identified as the main photocatalysis product. It was found that 0.1% Mn–TiO 2 samples resulted in the highest photocatalytic loss of CH 3 CHO under visible irradiation. This efficiency was drastically diminished at higher levels of Mn doping (1–33%). The CO 2 yields were the highest for 0.1% Mn–TiO 2 samples under UV irradiation, in agreement with the observed highest CH 3 CHO decomposition rates. It was demonstrated that low-level (0.1%) doping of TiO 2 with Mn results in a significant increase of their photocatalytic activity in the visible

  10. Breakthrough Curve Analysis for Column Dynamics Sorption of Mn(II) Ions from Wastewater by Using Mangostana garcinia Peel-Based Granular-Activated Carbon

    OpenAIRE

    Z. Z. Chowdhury; S. M. Zain; A. K. Rashid; R. F. Rafique; K. Khalid

    2013-01-01

    The potential of granular-activated carbon (GAC) derived from agrowaste of Mangostene (Mangostana garcinia) fruit peel was investigated in batch and fixed bed system as a replacement of current expensive methods for treating wastewater contaminated by manganese, Mn(II) cations. Batch equilibrium data was analyzed by Langmuir, Freundlich, and Temkin isotherm models at different temperatures. The effect of inlet metal ion concentration (50 mg/L, 70 mg/L, and 100 mg/L), feed flow rate (1 mL/min...

  11. Effect of irradiation on corrosion of low-activation austenite Cr-Mn steel in technological liquid mediums of nuclear power plant

    International Nuclear Information System (INIS)

    Demina, E.V.; Prusakova, M.D.; Vinogradova, N.A.; Orlova, G.D.; Nechaev, A.F.; Doil'nitsyn, V.A.

    2008-01-01

    Effect of γ-radiation on corrosion rate in cold-worked and annealed low-activation austenite 12Cr-20Mn steel has been studied. Corrosion tests were carried out in water solutions which simulate the coolant medium in the primary coolant circuit of WWER power reactor and in the circuit of multiple forced circulation of RBMK-1000 reactor as well as an aquatic environment in cooling pond for spent fuel. The worst radiation effect was observed in the cooling pond environment where the value of corrosion rate is increased by tens or hundreds times

  12. Combining traditional anatomy lectures with e-learning activities: how do students perceive their learning experience?

    Science.gov (United States)

    Lochner, Lukas; Wieser, Heike; Waldboth, Simone; Mischo-Kelling, Maria

    2016-02-21

    The purpose of this study was to investigate how students perceived their learning experience when combining traditional anatomy lectures with preparatory e-learning activities that consisted of fill-in-the-blank assignments, videos, and multiple-choice quizzes. A qualitative study was conducted to explore changes in study behaviour and perception of learning. Three group interviews with students were conducted and thematically analysed. Data was categorized into four themes: 1. Approaching the course material, 2. Understanding the material, 3. Consolidating the material, and 4. Perceived learning outcome. Students appreciated the clear structure of the course, and reported that online activities encouraged them towards a first engagement with the material. They felt that they were more active during in-class sessions, described self-study before the end-of-term exam as easier, and believed that contents would remain in their memories for a longer time. By adjusting already existing resources, lectures can be combined fairly easily and cost-effectively with preparatory e-learning activities. The creation of online components promote well-structured courses, can help minimize 'student passivity' as a characteristic element of lectures, and can support students in distributing their studies throughout the term, thus suggesting enhanced learning. Further research work should be designed to confirm the afore-mentioned findings through objective measurements of student learning outcomes.

  13. Combining traditional anatomy lectures with e-learning activities: how do students perceive their learning experience?

    Science.gov (United States)

    Wieser, Heike; Waldboth, Simone; Mischo-Kelling, Maria

    2016-01-01

    Objectives The purpose of this study was to investigate how students perceived their learning experience when combining traditional anatomy lectures with preparatory e-learning activities that consisted of fill-in-the-blank assignments, videos, and multiple-choice quizzes. Methods A qualitative study was conducted to explore changes in study behaviour and perception of learning. Three group interviews with students were conducted and thematically analysed. Results Data was categorized into four themes: 1. Approaching the course material, 2. Understanding the material, 3. Consolidating the material, and 4. Perceived learning outcome.  Students appreciated the clear structure of the course, and reported that online activities encouraged them towards a first engagement with the material. They felt that they were more active during in-class sessions, described self-study before the end-of-term exam as easier, and believed that contents would remain in their memories for a longer time. Conclusions By adjusting already existing resources, lectures can be combined fairly easily and cost-effectively with preparatory e-learning activities. The creation of online components promote well-structured courses, can help minimize ‘student passivity’ as a characteristic element of lectures, and can support students in distributing their studies throughout the term, thus suggesting enhanced learning. Further research work should be designed to confirm the afore-mentioned findings through objective measurements of student learning outcomes. PMID:26897012

  14. Reinforcement active learning in the vibrissae system: optimal object localization.

    Science.gov (United States)

    Gordon, Goren; Dorfman, Nimrod; Ahissar, Ehud

    2013-01-01

    Rats move their whiskers to acquire information about their environment. It has been observed that they palpate novel objects and objects they are required to localize in space. We analyze whisker-based object localization using two complementary paradigms, namely, active learning and intrinsic-reward reinforcement learning. Active learning algorithms select the next training samples according to the hypothesized solution in order to better discriminate between correct and incorrect labels. Intrinsic-reward reinforcement learning uses prediction errors as the reward to an actor-critic design, such that behavior converges to the one that optimizes the learning process. We show that in the context of object localization, the two paradigms result in palpation whisking as their respective optimal solution. These results suggest that rats may employ principles of active learning and/or intrinsic reward in tactile exploration and can guide future research to seek the underlying neuronal mechanisms that implement them. Furthermore, these paradigms are easily transferable to biomimetic whisker-based artificial sensors and can improve the active exploration of their environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Breakthrough Curve Analysis for Column Dynamics Sorption of Mn(II Ions from Wastewater by Using Mangostana garcinia Peel-Based Granular-Activated Carbon

    Directory of Open Access Journals (Sweden)

    Z. Z. Chowdhury

    2013-01-01

    Full Text Available The potential of granular-activated carbon (GAC derived from agrowaste of Mangostene (Mangostana garcinia fruit peel was investigated in batch and fixed bed system as a replacement of current expensive methods for treating wastewater contaminated by manganese, Mn(II cations. Batch equilibrium data was analyzed by Langmuir, Freundlich, and Temkin isotherm models at different temperatures. The effect of inlet metal ion concentration (50 mg/L, 70 mg/L, and 100 mg/L, feed flow rate (1 mL/min and 3 mL/min, and activated carbon bed height (4.5 cm and 3 cm on the breakthrough characteristics of the fixed bed sorption system were determined. The adsorption data were fitted with well-established column models, namely, Thomas, Yoon-Nelson, and Adams-Bohart. The results were best-fitted with Thomas and Yoon-Nelson models rather than Adams-Bohart model for all conditions. The column had been regenerated and reused consecutively for five cycles. The results demonstrated that the prepared activated carbon was suitable for removal of Mn(II ions from wastewater using batch as well as fixed bed sorption system.

  16. Cluster analysis of activity-time series in motor learning

    DEFF Research Database (Denmark)

    Balslev, Daniela; Nielsen, Finn Årup; Frutiger, Sally A.

    2002-01-01

    Neuroimaging studies of learning focus on brain areas where the activity changes as a function of time. To circumvent the difficult problem of model selection, we used a data-driven analytic tool, cluster analysis, which extracts representative temporal and spatial patterns from the voxel...... practice-related activity in a fronto-parieto-cerebellar network, in agreement with previous studies of motor learning. These voxels were separated from a group of voxels showing an unspecific time-effect and another group of voxels, whose activation was an artifact from smoothing. Hum. Brain Mapping 15...

  17. A Novel Teaching Tool Combined With Active-Learning to Teach Antimicrobial Spectrum Activity.

    Science.gov (United States)

    MacDougall, Conan

    2017-03-25

    Objective. To design instructional methods that would promote long-term retention of knowledge of antimicrobial pharmacology, particularly the spectrum of activity for antimicrobial agents, in pharmacy students. Design. An active-learning approach was used to teach selected sessions in a required antimicrobial pharmacology course. Students were expected to review key concepts from the course reader prior to the in-class sessions. During class, brief concept reviews were followed by active-learning exercises, including a novel schematic method for learning antimicrobial spectrum of activity ("flower diagrams"). Assessment. At the beginning of the next quarter (approximately 10 weeks after the in-class sessions), 360 students (three yearly cohorts) completed a low-stakes multiple-choice examination on the concepts in antimicrobial spectrum of activity. When data for students was pooled across years, the mean number of correct items was 75.3% for the items that tested content delivered with the active-learning method vs 70.4% for items that tested content delivered via traditional lecture (mean difference 4.9%). Instructor ratings on student evaluations of the active-learning approach were high (mean scores 4.5-4.8 on a 5-point scale) and student comments were positive about the active-learning approach and flower diagrams. Conclusion. An active-learning approach led to modestly higher scores in a test of long-term retention of pharmacology knowledge and was well-received by students.

  18. Assessing High School Student Learning on Science Outreach Lab Activities

    Science.gov (United States)

    Thomas, Courtney L.

    2012-01-01

    The effect of hands-on laboratory activities on secondary student learning was examined. Assessment was conducted over a two-year period, with 262 students participating the first year and 264 students the second year. Students took a prequiz, performed a laboratory activity (gas chromatography of alcohols, or photosynthesis and respiration), and…

  19. Teaching Sociology of Sport: An Active Learning Approach.

    Science.gov (United States)

    Blinde, Elaine M.

    1995-01-01

    Asserts that sport is a pervasive aspect of society. Presents and describes four learning activities designed to help students understand the significance of sport as a social institution. Maintains that, while the activities focus on the institution of sport, they can be used in a variety of sociology courses. (CFR)

  20. Active learning in physiology practical work | Allers | South African ...

    African Journals Online (AJOL)

    A statistical analysis of the results indicates that when students are actively involved in the teaching-learning process, they enhance their ability to use cognitive skills such as interpretation, judgement and problem-solving skills. The results also underline the importance of an active approach towards practical work and ...

  1. Constructivist Learning Environment During Virtual and Real Laboratory Activities

    Directory of Open Access Journals (Sweden)

    Ari Widodo

    2017-04-01

    Full Text Available Laboratory activities and constructivism are two notions that have been playing significant roles in science education. Despite common beliefs about the importance of laboratory activities, reviews reported inconsistent results about the effectiveness of laboratory activities. Since laboratory activities can be expensive and take more time, there is an effort to introduce virtual laboratory activities. This study aims at exploring the learning environment created by a virtual laboratory and a real laboratory. A quasi experimental study was conducted at two grade ten classes at a state high school in Bandung, Indonesia. Data were collected using a questionnaire called Constructivist Learning Environment Survey (CLES before and after the laboratory activities. The results show that both types of laboratories can create constructivist learning environments. Each type of laboratory activity, however, may be stronger in improving certain aspects compared to the other. While a virtual laboratory is stronger in improving critical voice and personal relevance, real laboratory activities promote aspects of personal relevance, uncertainty and student negotiation. This study suggests that instead of setting one type of laboratory against the other, lessons and follow up studies should focus on how to combine both types of laboratories to support better learning.

  2. Plastics in Our Environment: A Jigsaw Learning Activity

    Science.gov (United States)

    Hampton, Elaine; Wallace, Mary Ann; Lee, Wen-Yee

    2009-01-01

    In this lesson, a ready-to-teach cooperative reading activity, students learn about the effects of plastics in our environment, specifically that certain petrochemicals act as artificial estrogens and impact hormonal activities. Much of the content in this lesson was synthesized from recent medical research about the impact of xenoestrogens and…

  3. Active Learning Strategies for Introductory Light and Optics

    Science.gov (United States)

    Sokoloff, David R.

    2016-01-01

    There is considerable evidence that traditional approaches are ineffective in teaching physics concepts, including light and optics concepts. A major focus of the work of the Activity Based Physics Group has been on the development of active learning curricula like RealTime Physics (RTP) labs and Interactive Lecture Demonstrations (ILDs). Among…

  4. Marketing Feud: An Active Learning Game of (Mis)Perception

    Science.gov (United States)

    Schee, Brian A. Vander

    2011-01-01

    This paper presents the results of implementing an active learning activity in the principles of marketing course adapted from the television show "Family Feud". The objectives of the Marketing Feud game include increasing awareness of marketing misperceptions, clarifying marketing misunderstandings, encouraging class participation, and building…

  5. Disk Operating System--DOS. Teacher Packet. Learning Activity Packets.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    The Learning Activity Packets (LAPs) contained in this manual are designed to assist the beginning user in understanding DOS (Disk Operating System). LAPs will not work with any version below DOS Version 3.0 and do not address the enhanced features of versions 4.0 or higher. These elementary activities cover only the DOS commands necessary to…

  6. Lasers. Technology Learning Activity. Teacher Edition. Technology Education Series.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the materials required for presenting an 8-day competency-based technology learning activity (TLA) designed to introduce students in grades 6-10 to advances and career opportunities in the field of laser technology. The guide uses a series of hands-on exploratory experiences into which activities to help students develop…

  7. Learning through debate during problem-based learning: an active learning strategy.

    Science.gov (United States)

    Mumtaz, Sadaf; Latif, Rabia

    2017-09-01

    We explored medical student's views and perceptions of a series of debates conducted during problem-based learning (PBL) practiced as a part of the Spiral curriculum at the Imam Abdulrahman Bin Faisal University, Saudi Arabia. A series of debates were employed during PBL sessions for second-year female medical students, over the period 2014-2016. Each cohort of students was randomly split into 10 small PBL groups and exposed to weekly PBL activity. Within each group, the students were divided into a proposition half and an opposition half. Students were given 1 wk for debate preparation. The students' responses were recorded on a formulated questionnaire. Descriptive statistics were used to analyze quantitative data, and results are presented as percentages. The usefulness of debate in alleviating potential difficulties in communicating with patients was agreed to by 69% ( n = 126) of participants. That these sessions evoked critical thinking among students was reported by 78% ( n = 142). This series of debates helped 61% ( n = 111) of students to learn effectively about controversial issues. Seventy-one percent ( n = 130) considered that debate promoted argument generation and interpretation skills. Enhanced ability to analyze and research evidence was reported by 59% ( n = 108) of students. One hundred and thirteen students (62%) agreed that debate helped them to improve clinical decision-making, and 75% of students agreed that debates encouraged tolerance toward diverse viewpoints/convincing strategies. The majority of our medical students found debating enhanced analytic decision-making, communication, and critical thinking skills. Copyright © 2017 the American Physiological Society.

  8. Invention activities as preparation for learning laboratory data handling skills

    Science.gov (United States)

    Day, James

    2012-10-01

    Undergraduate physics laboratories are often driven by a mix of goals, and usually enough of them to cause cognitive overload for the student. Our recent findings align well with studies indicating that students often exit a physics lab without having properly learned how to handle real data. The value of having students explore the underlying structure of a problem before being able to solve it has been shown as an effective way to ready students for learning. Borrowing on findings from the fields of education and cognitive psychology, we use ``invention activities'' to precede direct instruction and bolster learning. In this talk I will show some of what we have learned about students' data handling skills, explain how an invention activity works, and share some observations of successful transfer.

  9. ONLINE EDUCATION, ACTIVE LEARNING, AND ANDRAGOGY: An approach for Student Engagement

    OpenAIRE

    CARUTH, Gail D.

    2015-01-01

    Online learning opportunities have become essential for today’s colleges and universities. Online technology can support active learning approaches to learning. The purpose of the paper was to investigate why active learning in online classes has a positive effect on student engagement. A review of the literature revealed that research studies have been conducted to investigate the benefits of active learning. There exists extensive evidence to support the notion that active learning enhances...

  10. Learning shapes spontaneous activity itinerating over memorized states.

    Directory of Open Access Journals (Sweden)

    Tomoki Kurikawa

    Full Text Available Learning is a process that helps create neural dynamical systems so that an appropriate output pattern is generated for a given input. Often, such a memory is considered to be included in one of the attractors in neural dynamical systems, depending on the initial neural state specified by an input. Neither neural activities observed in the absence of inputs nor changes caused in the neural activity when an input is provided were studied extensively in the past. However, recent experimental studies have reported existence of structured spontaneous neural activity and its changes when an input is provided. With this background, we propose that memory recall occurs when the spontaneous neural activity changes to an appropriate output activity upon the application of an input, and this phenomenon is known as bifurcation in the dynamical systems theory. We introduce a reinforcement-learning-based layered neural network model with two synaptic time scales; in this network, I/O relations are successively memorized when the difference between the time scales is appropriate. After the learning process is complete, the neural dynamics are shaped so that it changes appropriately with each input. As the number of memorized patterns is increased, the generated spontaneous neural activity after learning shows itineration over the previously learned output patterns. This theoretical finding also shows remarkable agreement with recent experimental reports, where spontaneous neural activity in the visual cortex without stimuli itinerate over evoked patterns by previously applied signals. Our results suggest that itinerant spontaneous activity can be a natural outcome of successive learning of several patterns, and it facilitates bifurcation of the network when an input is provided.

  11. [Flipped classroom as a strategy to enhance active learning].

    Science.gov (United States)

    Wakabayashi, Noriyuki

    2015-03-01

    This paper reviews the introduction of a flipped class for fourth grade dentistry students, and analyzes the characteristics of the learning method. In fiscal 2013 and 2014, a series of ten three-hour units for removable partial prosthodontics were completed with the flipped class method; a lecture video of approximately 60 minutes was made by the teacher (author) and uploaded to the university's e-learning website one week before each class. Students were instructed to prepare for the class by watching the streaming video on their PC, tablet, or smartphone. In the flipped class, students were not given a lecture, but were asked to solve short questions displayed on screen, to make a short presentation about a part of the video lecture, and to discuss a critical question related to the main subject of the day. An additional team-based learning (TBL) session with individual and group answers was implemented. The average individual scores were considerably higher in the last two years, when the flipped method was implemented, than in the three previous years when conventional lectures were used. The following learning concepts were discussed: the role of the flipped method as an active learning strategy, the efficacy of lecture videos and short questions, students' participation in the class discussion, present-day value of the method, cooperation with TBL, the significance of active learning in relation with the students' learning ability, and the potential increase in the preparation time and workload for students.

  12. Trends in Research on Writing as a Learning Activity

    Directory of Open Access Journals (Sweden)

    Perry D. Klein

    2016-02-01

    Full Text Available This article discusses five trends in research on writing as a learning activity. Firstly, earlier decades were marked by conflicting views about the effects of writing on learning; in the past decade, the use of meta-analysis has shown that the effects of writing on learning are reliable, and that several variables mediate and moderate these effects. Secondly, in earlier decades, it was thought that text as a medium inherently elicited thinking and learning. Research during the past decade has indicated that writing to learn is a self-regulated activity, dependent on the goals and strategies of the writer. Thirdly, the Writing Across the Curriculum (WAC movement emphasized domain-general approaches to WTL. Much recent research is consistent with the Writing in the Disciplines (WID movement, incorporating genres that embody forms of reasoning specific to a given discipline. Fourthly, WTL as a classroom practice was always partially social, but the theoretical conceptualization of it was largely individual. During the past two decades, WTL has broadened to include theories and research that integrate social and psychological processes. Fifthly, WTL research has traditionally focused on epistemic learning in schools; more recently, it has been extended to include reflective learning in the professions and additional kinds of outcomes.

  13. Spontaneous brain activity predicts learning ability of foreign sounds.

    Science.gov (United States)

    Ventura-Campos, Noelia; Sanjuán, Ana; González, Julio; Palomar-García, María-Ángeles; Rodríguez-Pujadas, Aina; Sebastián-Gallés, Núria; Deco, Gustavo; Ávila, César

    2013-05-29

    Can learning capacity of the human brain be predicted from initial spontaneous functional connectivity (FC) between brain areas involved in a task? We combined task-related functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) before and after training with a Hindi dental-retroflex nonnative contrast. Previous fMRI results were replicated, demonstrating that this learning recruited the left insula/frontal operculum and the left superior parietal lobe, among other areas of the brain. Crucially, resting-state FC (rs-FC) between these two areas at pretraining predicted individual differences in learning outcomes after distributed (Experiment 1) and intensive training (Experiment 2). Furthermore, this rs-FC was reduced at posttraining, a change that may also account for learning. Finally, resting-state network analyses showed that the mechanism underlying this reduction of rs-FC was mainly a transfer in intrinsic activity of the left frontal operculum/anterior insula from the left frontoparietal network to the salience network. Thus, rs-FC may contribute to predict learning ability and to understand how learning modifies the functioning of the brain. The discovery of this correspondence between initial spontaneous brain activity in task-related areas and posttraining performance opens new avenues to find predictors of learning capacities in the brain using task-related fMRI and rs-fMRI combined.

  14. ANALYTiC: An Active Learning System for Trajectory Classification.

    Science.gov (United States)

    Soares Junior, Amilcar; Renso, Chiara; Matwin, Stan

    2017-01-01

    The increasing availability and use of positioning devices has resulted in large volumes of trajectory data. However, semantic annotations for such data are typically added by domain experts, which is a time-consuming task. Machine-learning algorithms can help infer semantic annotations from trajectory data by learning from sets of labeled data. Specifically, active learning approaches can minimize the set of trajectories to be annotated while preserving good performance measures. The ANALYTiC web-based interactive tool visually guides users through this annotation process.

  15. Application of active learning modalities to achieve medical genetics competencies and their learning outcome assessments

    Directory of Open Access Journals (Sweden)

    Hagiwara N

    2017-12-01

    Full Text Available Nobuko Hagiwara Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, CA, USA Abstract: The steadily falling costs of genome sequencing, coupled with the growing number of genetic tests with proven clinical validity, have made the use of genetic testing more common in clinical practice. This development has necessitated nongeneticist physicians, especially primary care physicians, to become more responsible for assessing genetic risks for their patients. Providing undergraduate medical students a solid foundation in genomic medicine, therefore, has become all the more important to ensure the readiness of future physicians in applying genomic medicine to their patient care. In order to further enhance the effectiveness of instructing practical skills in medical genetics, the emphasis of active learning modules in genetics curriculum at medical schools has increased in recent years. This is because of the general acceptance of a better efficacy of active learner-centered pedagogy over passive lecturer-centered pedagogy. However, an objective standard to evaluate students’ skill levels in genomic medicine achieved by active learning is currently missing. Recently, entrustable professional activities (EPAs in genomic medicine have been proposed as a framework for developing physician competencies in genomic medicine. EPAs in genomic medicine provide a convenient guideline for not only developing genomic medicine curriculum but also assessing students’ competency levels in practicing genomic medicine. In this review, the efficacy of different types of active learning modules reported for medical genetics curricula is discussed using EPAs in genomic medicine as a common evaluation standard for modules’ learning outcomes. The utility of the EPAs in genomic medicine for designing active learning modules in undergraduate medical genetics curricula is also discussed. Keywords

  16. Active Learning for Automatic Audio Processing of Unwritten Languages (ALAPUL)

    Science.gov (United States)

    2016-07-01

    AFRL-RH-WP-TR-2016-0074 ACTIVE LEARNING FOR AUTOMATIC AUDIO PROCESSING OF UNWRITTEN LANGUAGES (ALAPUL) Dimitra Vergyri Andreas Kathol Wen Wang...FA8650-15-C-9101 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) *Dimitra Vergyri; Andreas Kathol; Wen Wang; Chris Bartels; Julian VanHout...feature transform through deep auto-encoders for better phone recognition performance. We target iterative learning to improve the system through

  17. Using human brain activity to guide machine learning.

    Science.gov (United States)

    Fong, Ruth C; Scheirer, Walter J; Cox, David D

    2018-03-29

    Machine learning is a field of computer science that builds algorithms that learn. In many cases, machine learning algorithms are used to recreate a human ability like adding a caption to a photo, driving a car, or playing a game. While the human brain has long served as a source of inspiration for machine learning, little effort has been made to directly use data collected from working brains as a guide for machine learning algorithms. Here we demonstrate a new paradigm of "neurally-weighted" machine learning, which takes fMRI measurements of human brain activity from subjects viewing images, and infuses these data into the training process of an object recognition learning algorithm to make it more consistent with the human brain. After training, these neurally-weighted classifiers are able to classify images without requiring any additional neural data. We show that our neural-weighting approach can lead to large performance gains when used with traditional machine vision features, as well as to significant improvements with already high-performing convolutional neural network features. The effectiveness of this approach points to a path forward for a new class of hybrid machine learning algorithms which take both inspiration and direct constraints from neuronal data.

  18. Diverse Expected Gradient Active Learning for Relative Attributes.

    Science.gov (United States)

    You, Xinge; Wang, Ruxin; Tao, Dacheng

    2014-06-02

    The use of relative attributes for semantic understanding of images and videos is a promising way to improve communication between humans and machines. However, it is extremely labor- and time-consuming to define multiple attributes for each instance in large amount of data. One option is to incorporate active learning, so that the informative samples can be actively discovered and then labeled. However, most existing active-learning methods select samples one at a time (serial mode), and may therefore lose efficiency when learning multiple attributes. In this paper, we propose a batch-mode active-learning method, called Diverse Expected Gradient Active Learning (DEGAL). This method integrates an informativeness analysis and a diversity analysis to form a diverse batch of queries. Specifically, the informativeness analysis employs the expected pairwise gradient length as a measure of informativeness, while the diversity analysis forces a constraint on the proposed diverse gradient angle. Since simultaneous optimization of these two parts is intractable, we utilize a two-step procedure to obtain the diverse batch of queries. A heuristic method is also introduced to suppress imbalanced multi-class distributions. Empirical evaluations of three different databases demonstrate the effectiveness and efficiency of the proposed approach.

  19. Unsupervised active learning based on hierarchical graph-theoretic clustering.

    Science.gov (United States)

    Hu, Weiming; Hu, Wei; Xie, Nianhua; Maybank, Steve

    2009-10-01

    Most existing active learning approaches are supervised. Supervised active learning has the following problems: inefficiency in dealing with the semantic gap between the distribution of samples in the feature space and their labels, lack of ability in selecting new samples that belong to new categories that have not yet appeared in the training samples, and lack of adaptability to changes in the semantic interpretation of sample categories. To tackle these problems, we propose an unsupervised active learning framework based on hierarchical graph-theoretic clustering. In the framework, two promising graph-theoretic clustering algorithms, namely, dominant-set clustering and spectral clustering, are combined in a hierarchical fashion. Our framework has some advantages, such as ease of implementation, flexibility in architecture, and adaptability to changes in the labeling. Evaluations on data sets for network intrusion detection, image classification, and video classification have demonstrated that our active learning framework can effectively reduce the workload of manual classification while maintaining a high accuracy of automatic classification. It is shown that, overall, our framework outperforms the support-vector-machine-based supervised active learning, particularly in terms of dealing much more efficiently with new samples whose categories have not yet appeared in the training samples.

  20. Exergaming: Syncing Physical Activity and Learning

    Science.gov (United States)

    Hicks, Lisa; Higgins, John

    2010-01-01

    This article discusses exergaming, a groundbreaking type of video game which is creating a revolution in physical education. Exergaming combines physical activity and video gaming to create an enjoyable and appealing way for students to be physically active. An extremely popular choice in this genre is the music video/dance rhythm game (MVDG). One…

  1. Activities To Help in Learning about Functions.

    Science.gov (United States)

    Willoughby, Stephen S.

    1997-01-01

    Describes several activities and games that provide an introduction to the concept of function. Suggests that experiences should depend more on students' experiences and understanding and less on the memorization of unmotivated conventions with abstract symbols. Includes activities for a calculator as a function machine, composite functions, and…

  2. Active Learning? Not with My Syllabus!

    Science.gov (United States)

    Ernst, Michael D.

    2012-01-01

    We describe an approach to teaching probability that minimizes the amount of class time spent on the topic while also providing a meaningful (dice-rolling) activity to get students engaged. The activity, which has a surprising outcome, illustrates the basic ideas of informal probability and how probability is used in statistical inference.…

  3. An Activity for Learning to Find Percentiles

    Science.gov (United States)

    Cox, Richard G.

    2016-01-01

    This classroom activity is designed to help students practice calculating percentiles. The approach of the activity involves physical sorting and full classroom participation in each calculation. The design encourages a more engaged approach than simply having students make a calculation with numbers on a paper.

  4. Five Experiential Learning Activities in Addictions Education

    Science.gov (United States)

    Warren, Jane A.; Hof, Kiphany R.; McGriff, Deborah; Morris, Lay-nah Blue

    2012-01-01

    This article describes five creative experiential classroom activities used in teaching addictions. The activities were integrated into the classroom curriculum and were processed weekly in focused dialogue. Student reflections throughout the article add depth to the meaning gained from the experience of the change process. The students' feedback…

  5. Active teaching methods, studying responses and learning

    DEFF Research Database (Denmark)

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching....

  6. ASPECT: A Survey to Assess Student Perspective of Engagement in an Active-Learning Classroom

    Science.gov (United States)

    Wiggins, Benjamin L.; Eddy, Sarah L.; Wener-Fligner, Leah; Freisem, Karen; Grunspan, Daniel Z.; Theobald, Elli J.; Timbrook, Jerry; Crowe, Alison J.

    2017-01-01

    The primary measure used to determine relative effectiveness of in-class activities has been student performance on pre/posttests. However, in today's active-learning classrooms, learning is a social activity, requiring students to interact and learn from their peers. To develop effective active-learning exercises that engage students, it is…

  7. Precipitation sensitivity to alloy composition in Fe-Cr-Mn austenitic steels developed for reduced activation for fusion application

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Klueh, R.L.

    1988-01-01

    Special austenitic steels are being designed in which alloying elements like Mo, Nb, and Ni are replaced with Mn, W, V, Ti, and/or Ta to reduce the long-term radioactivity induced by fusion reactor irradiation. However, the new steels still need to have properties otherwise similar to commercial steels like type 316. Precipitation strongly affects strength and radiation-resistance in austenitic steels during irradiation at 400--600/degree/C, and precipitation is also usually quite sensitive to alloy composition. The initial stage of development was to define a base Fe-Cr-Mn-C composition that formed stable austenite after annealing and cold-working, and resisted recovery or excessive formation of coarse carbide and intermetallic phases during elevated temperature annealing. These studies produced a Fe-12Cr-20Mn-0.25C base alloy. The next stage was to add the minor alloying elements W, Ti, V, P, and B for more strength and radiation-resistance. One of the goals was to produce fine MC precipitation behavior similar to the Ti-modified Fe-Cr-Ni prime candidate alloy (PCA). Additions of Ti+V+P+B produced fine MC precipitation along network dislocations and recovery/recrystallization resistance in 20% cold worked material aged at 800/degree/C for 166h, whereas W, Ti, W+Ti, or Ti+P+B additions did not. Addition of W+Ti+V+P+B also produced fine MC, but caused some σ phase formation and more recrystallization as well. 29 refs., 14 figs., 9 tabs

  8. Biosorption of Cd, Cr, Mn, and Pb from aqueous solutions by Bacillus sp strains isolated from industrial waste activate sludge

    OpenAIRE

    Rocío García; Juan Campos; Julio Alfonso Cruz; Ma. Elena Calderón; Ma. Elena Rayna; Germán Buitrón

    2016-01-01

    Los microorganismos tienen capacidad de acumular metales pesados como agentes bioadsorbentes ofreciendo una alternativa para la remoción de metales tóxicos en aguas de efluentes industriales. El objetivo del presente trabajo fue aislar e identificar bacterias tolerantes a los metales pesados (Cd, Cr, Mn y Pb) de lodos activados provenientes de la planta de tratamiento de agua del Municipio de Santa Rosa Jáuregui, Querétaro. Para seleccionar las bacterias que son tolerantes a los metales se ai...

  9. Performance in physiology evaluation: possible improvement by active learning strategies.

    Science.gov (United States)

    Montrezor, Luís H

    2016-12-01

    The evaluation process is complex and extremely important in the teaching/learning process. Evaluations are constantly employed in the classroom to assist students in the learning process and to help teachers improve the teaching process. The use of active methodologies encourages students to participate in the learning process, encourages interaction with their peers, and stimulates thinking about physiological mechanisms. This study examined the performance of medical students on physiology over four semesters with and without active engagement methodologies. Four activities were used: a puzzle, a board game, a debate, and a video. The results show that engaging in activities with active methodologies before a physiology cognitive monitoring test significantly improved student performance compared with not performing the activities. We integrate the use of these methodologies with classic lectures, and this integration appears to improve the teaching/learning process in the discipline of physiology and improves the integration of physiology with cardiology and neurology. In addition, students enjoy the activities and perform better on their evaluations when they use them. Copyright © 2016 The American Physiological Society.

  10. Active learning approach in Moodle for the organization of student’s self-study practice-based learning activities

    Directory of Open Access Journals (Sweden)

    Ivanova Veronica

    2016-01-01

    Full Text Available Nowadays e-learning tools and delivery methods have been constantly expanding. Employs use e-learning to train their employees more often and often. New and experienced employees have the opportunity to improve upon their knowledge base and expand their skill sets. At home, individuals are granted the access to the programs that provided them with the ability to earn online degrees and enrich their lives through the expanded knowledge. The paper focuses on the analysis of the advantages and disadvantages of e- learning. The ways of applying on-line training used by employers are demonstrated. The experience of implementing active methods of e-learning is described as well as the conclusion about the possibility of their application is made. The paper also presents the results of the survey conducted among TPU teacher and students concerning the advisability of e-learning usage.

  11. Embedding responses in spontaneous neural activity shaped through sequential learning.

    Directory of Open Access Journals (Sweden)

    Tomoki Kurikawa

    Full Text Available Recent experimental measurements have demonstrated that spontaneous neural activity in the absence of explicit external stimuli has remarkable spatiotemporal structure. This spontaneous activity has also been shown to play a key role in the response to external stimuli. To better understand this role, we proposed a viewpoint, "memories-as-bifurcations," that differs from the traditional "memories-as-attractors" viewpoint. Memory recall from the memories-as-bifurcations viewpoint occurs when the spontaneous neural activity is changed to an appropriate output activity upon application of an input, known as a bifurcation in dynamical systems theory, wherein the input modifies the flow structure of the neural dynamics. Learning, then, is a process that helps create neural dynamical systems such that a target output pattern is generated as an attractor upon a given input. Based on this novel viewpoint, we introduce in this paper an associative memory model with a sequential learning process. Using a simple hebbian-type learning, the model is able to memorize a large number of input/output mappings. The neural dynamics shaped through the learning exhibit different bifurcations to make the requested targets stable upon an increase in the input, and the neural activity in the absence of input shows chaotic dynamics with occasional approaches to the memorized target patterns. These results suggest that these dynamics facilitate the bifurcations to each target attractor upon application of the corresponding input, which thus increases the capacity for learning. This theoretical finding about the behavior of the spontaneous neural activity is consistent with recent experimental observations in which the neural activity without stimuli wanders among patterns evoked by previously applied signals. In addition, the neural networks shaped by learning properly reflect the correlations of input and target-output patterns in a similar manner to those designed in

  12. Using evaluation strategically to promote active learning

    DEFF Research Database (Denmark)

    Münster, Marie

    as to grade them. For this purpose it was decided to change one report into a poster including a 15 minute group oral presentation. The oral examination allows for individual assessment of the students, for assessment of conceptual understanding and for learning during the examination. This type of evaluation...... is however very time consuming and a written examination will facilitate a better evaluation of whether the core elements of the course (including the tools used for the two projects) are achieved at an individual level, so it was decided to have a 4 hour written examination instead. Evaluation of conceptual...... understanding was undertaken through more open ended questions. Results: Using a poster instead of a report for one of the projects was found to be very successful. The students used most of their time on discussing and using the tool, and less on reporting, which was the purpose. When asked, they claimed...

  13. Writing Assignments that Promote Active Learning

    Science.gov (United States)

    Narayanan, M.

    2014-12-01

    Encourage students to write a detailed, analytical report correlating classroom discussions to an important historical event or a current event. Motivate students interview an expert from industry on a topic that was discussed in class. Ask the students to submit a report with supporting sketches, drawings, circuit diagrams and graphs. Propose that the students generate a complete a set of reading responses pertaining to an assigned topic. Require each student to bring in one comment or one question about an assigned reading. The assignment should be a recent publication in an appropriate journal. Have the students conduct a web search on an assigned topic. Ask them to generate a set of ideas that can relate to classroom discussions. Provide the students with a study guide. The study guide should provide about 10 or 15 short topics. Quiz the students on one or two of the topics. Encourage the students to design or develop some creative real-world examples based on a chapter discussed or a topic of interest. Require that students originate, develop, support and defend a viewpoint using a specifically assigned material. Make the students practice using or utilizing a set of new technical terms they have encountered in an assigned chapter. Have students develop original examples explaining the different terms. Ask the students to select one important terminology from the previous classroom discussions. Encourage the students to explain why they selected that particular word. Ask them to talk about the importance of the terminology from the point of view of their educational objectives and future career. Angelo, T. A. (1991). Ten easy pieces: Assessing higher learning in four dimensions. In T. A. Angelo (Ed.), Classroom research: Early lessons from success (pp. 17-31). New Directions for Teaching and Learning, No. 46. San Francisco: Jossey-Bass.

  14. Thermally activated demagnetization in (La0.97 Ca0.03)0.96Mn0.96 O3-δ

    International Nuclear Information System (INIS)

    Alonso, J.M.; Arroyo, A.; Cortes-Gil, R.; Garcia, M.A.; Gonzalez-Calbet, J.M.; Gonzalez, J.M.; Hernando, A.; Rojo, J.M.; Vallet-Regi, M.

    2005-01-01

    We report on the temperature dependence of the relaxation properties of a Mn perovskite with overall composition (La 0.97 Ca 0.03 ) 0.96 (Mn 4+ 0.07 Mn 3+ 0.93 ) 0.96 O 2.90 .Our data are correlated with the simultaneous occurrence in the sample of metallic double-exchange magnetically coupled, Mn 4+ clusters and of insulating superexchange coupled regions.

  15. Using Active Learning for Speeding up Calibration in Simulation Models.

    Science.gov (United States)

    Cevik, Mucahit; Ergun, Mehmet Ali; Stout, Natasha K; Trentham-Dietz, Amy; Craven, Mark; Alagoz, Oguzhan

    2016-07-01

    Most cancer simulation models include unobservable parameters that determine disease onset and tumor growth. These parameters play an important role in matching key outcomes such as cancer incidence and mortality, and their values are typically estimated via a lengthy calibration procedure, which involves evaluating a large number of combinations of parameter values via simulation. The objective of this study is to demonstrate how machine learning approaches can be used to accelerate the calibration process by reducing the number of parameter combinations that are actually evaluated. Active learning is a popular machine learning method that enables a learning algorithm such as artificial neural networks to interactively choose which parameter combinations to evaluate. We developed an active learning algorithm to expedite the calibration process. Our algorithm determines the parameter combinations that are more likely to produce desired outputs and therefore reduces the number of simulation runs performed during calibration. We demonstrate our method using the previously developed University of Wisconsin breast cancer simulation model (UWBCS). In a recent study, calibration of the UWBCS required the evaluation of 378 000 input parameter combinations to build a race-specific model, and only 69 of these combinations produced results that closely matched observed data. By using the active learning algorithm in conjunction with standard calibration methods, we identify all 69 parameter combinations by evaluating only 5620 of the 378 000 combinations. Machine learning methods hold potential in guiding model developers in the selection of more promising parameter combinations and hence speeding up the calibration process. Applying our machine learning algorithm to one model shows that evaluating only 1.49% of all parameter combinations would be sufficient for the calibration. © The Author(s) 2015.

  16. Active Learning by Design: An Undergraduate Introductory Public Health Course

    Directory of Open Access Journals (Sweden)

    Karin eYeatts

    2014-12-01

    Full Text Available Principles of active learning were used to design and implement an introductory public health course. Students were introduced to the breadth and practice of public health through team and individual-based activities. Team assignments covered topics in epidemiology, biostatistics, health behavior, nutrition, maternal and child health, environment, and health policy. Students developed an appreciation of the population perspective through an experience trip and related intervention project in a public health area of their choice. Students experienced several key critical component elements of a public health undergraduate major; they cover key public health domains, experience public health practice, and integrated concepts with their assignments. In this paper, course assignments, lessons learned, and student successes are described. Given the increased growth in the undergraduate public health major, these active learning assignments may be of interest to undergraduate public health programs at both liberal arts colleges and research universities.

  17. Active learning in the presence of unlabelable examples

    Science.gov (United States)

    Mazzoni, Dominic; Wagstaff, Kiri

    2004-01-01

    We propose a new active learning framework where the expert labeler is allowed to decline to label any example. This may be necessary because the true label is unknown or because the example belongs to a class that is not part of the real training problem. We show that within this framework, popular active learning algorithms (such as Simple) may perform worse than random selection because they make so many queries to the unlabelable class. We present a method by which any active learning algorithm can be modified to avoid unlabelable examples by training a second classifier to distinguish between the labelable and unlabelable classes. We also demonstrate the effectiveness of the method on two benchmark data sets and a real-world problem.

  18. Quick and enhanced degradation of bisphenol A by activation of potassium peroxymonosulfate to SO4rad - with Mn-doped BiFeO3 nanoparticles as a heterogeneous Fenton-like catalyst

    Science.gov (United States)

    Soltani, Tayyebeh; Tayyebi, Ahmad; Lee, Byeong-Kyu

    2018-05-01

    Mn-doped BiFeO3 magnetic nanoparticles (BFO MNPs), namely BiFe1-xMnxO3 (x = 0.05 and 0.10), were successfully synthesized using a simple and novel sol-gel method and then applied as a highly efficient peroxymonosulfate (KHSO5, PMS) activation catalyst for the fast degradation of bisphenol A (BPA) from aqueous solution. The strong PMS activation ability of 10% Mn-doped BFO MNPs without any metal leaching due to the simultaneous effects of iron and manganese ions in the production of radical sulfate (SO4rad -), caused complete BPA degradation in 15 min, which was much faster than that using combinations with H2O2. TOC was reduced to 33%, 23% and 13% by PMS activated with BFO, 5 and 10% Mn doped BFO, respectively, which are 2.1, 2.6 and 3.15-fold lower than that same nanoparticles activated with H2O2. The photocatalytic mechanism of BPA with the simultaneous effects of iron and manganese ions in Mn-doped BFO was explored. The addition of KBrO3 and NaNO3 salts into Mn-doped BFO/PMS system reduced the complete BPA degradation time to 10 min, whereas Na2CO3 and NaCl salt addition retarded it, because salt addition can generate radical species that are either more or less active than SO4rad -.

  19. Active explorers show low learning performance in a social insect

    Institute of Scientific and Technical Information of China (English)

    Eve UDINO; Margot PEREZ; Claudio CARERE; Patrizia d'ETTORRE

    2017-01-01

    An intriguing question in behavioral biology is whether consistent individual differences (called animal personalities) relate to variation in cognitive performance because commonly measured personality traits may be associated with risk-reward trade-offs.Social insects,whose learning abilities have been extensively characterized,show consistent behavioral variability,both at colony and at individual level.We investigated the possible link between personality traits and learning performance in the carpenter ant Camponotus aethiops.Exploratory activity,sociability,and aggression were assessed twice in ant foragers.Behaviors differed among individuals,they were partly repeatable across time and exploratory activity correlated positively with aggression.Learning abilities were quantified by differential conditioning of the maxilla-labium extension response,a task that requires cue perception and information storage.We found that exploratory activity of individual ants significantly predicted learning performance:"active-explorers" were slower in learning the task than "inactive-explorers".The results suggest for the first time a link between a personality trait and cognitive performance in eusocial insects,and that the underlying individual variability could affect colony performance and success.

  20. Mn(II,III) oxidation and MnO2 mineralization by an expressed bacterial multicopper oxidase

    Science.gov (United States)

    Butterfield, Cristina N.; Soldatova, Alexandra V.; Lee, Sung-Woo; Spiro, Thomas G.; Tebo, Bradley M.

    2013-01-01

    Reactive Mn(IV) oxide minerals are ubiquitous in the environment and control the bioavailability and distribution of many toxic and essential elements and organic compounds. Their formation is thought to be dependent on microbial enzymes, because spontaneous Mn(II) to Mn(IV) oxidation is slow. Several species of marine Bacillus spores oxidize Mn(II) on their exosporium, the outermost layer of the spore, encrusting them with Mn(IV) oxides. Molecular studies have identified the mnx (Mn oxidation) genes, including mnxG, encoding a putative multicopper oxidase (MCO), as responsible for this two-electron oxidation, a surprising finding because MCOs only catalyze single-electron transfer reactions. Characterization of the enzymatic mechanism has been hindered by the lack of purified protein. By purifying active protein from the mnxDEFG expression construct, we found that the resulting enzyme is a blue (absorption maximum 590 nm) complex containing MnxE, MnxF, and MnxG proteins. Further, by analyzing the Mn(II)- and (III)-oxidizing activity in the presence of a Mn(III) chelator, pyrophosphate, we found that the complex facilitates both electron transfers from Mn(II) to Mn(III) and from Mn(III) to Mn(IV). X-ray absorption spectroscopy of the Mn mineral product confirmed its similarity to Mn(IV) oxides generated by whole spores. Our results demonstrate that Mn oxidation from soluble Mn(II) to Mn(IV) oxides is a two-step reaction catalyzed by an MCO-containing complex. With the purification of active Mn oxidase, we will be able to uncover its mechanism, broadening our understanding of Mn mineral formation and the bioinorganic capabilities of MCOs. PMID:23818588

  1. Active Learning and Cooperative Learning in the Organic Chemistry Lecture Class

    Science.gov (United States)

    Paulson, Donald R.

    1999-08-01

    Faculty in the physical sciences are one of the academic groups least receptive to the use of active learning strategies and cooperative learning in their classrooms. This is particularly so in traditional lecture classes. It is the objective of this paper to show how effective these techniques can be in improving student performance in classes. The use of active learning strategies and cooperative learning groups in my organic chemistry lecture classes has increased the overall pass rate in my classes by an astounding 20-30% over the traditional lecture mode. This has been accomplished without any reduction in "standards". The actual methods employed are presented as well as a discussion of how I came to radically change the way I teach my classes.

  2. Developing a Mobile Learning Management System for Outdoors Nature Science Activities Based on 5E Learning Cycle

    Science.gov (United States)

    Lai, Ah-Fur; Lai, Horng-Yih; Chuang, Wei-Hsiang; Wu, Zih-Heng

    2015-01-01

    Traditional outdoor learning activities such as inquiry-based learning in nature science encounter many dilemmas. Due to prompt development of mobile computing and widespread of mobile devices, mobile learning becomes a big trend on education. The main purpose of this study is to develop a mobile-learning management system for overcoming the…

  3. A Preliminary Investigation of Self-Directed Learning Activities in a Non-Formal Blended Learning Environment

    Science.gov (United States)

    Schwier, Richard A.; Morrison, Dirk; Daniel, Ben K.

    2009-01-01

    This research considers how professional participants in a non-formal self-directed learning environment (NFSDL) made use of self-directed learning activities in a blended face-to-face and on line learning professional development course. The learning environment for the study was a professional development seminar on teaching in higher education…

  4. High-frequency TRNS reduces BOLD activity during visuomotor learning.

    Directory of Open Access Journals (Sweden)

    Catarina Saiote

    Full Text Available Transcranial direct current stimulation (tDCS and transcranial random noise stimulation (tRNS consist in the application of electrical current of small intensity through the scalp, able to modulate perceptual and motor learning, probably by changing brain excitability. We investigated the effects of these transcranial electrical stimulation techniques in the early and later stages of visuomotor learning, as well as associated brain activity changes using functional magnetic resonance imaging (fMRI. We applied anodal and cathodal tDCS, low-frequency and high-frequency tRNS (lf-tRNS, 0.1-100 Hz; hf-tRNS 101-640 Hz, respectively and sham stimulation over the primary motor cortex (M1 during the first 10 minutes of a visuomotor learning paradigm and measured performance changes for 20 minutes after stimulation ceased. Functional imaging scans were acquired throughout the whole experiment. Cathodal tDCS and hf-tRNS showed a tendency to improve and lf-tRNS to hinder early learning during stimulation, an effect that remained for 20 minutes after cessation of stimulation in the late learning phase. Motor learning-related activity decreased in several regions as reported previously, however, there was no significant modulation of brain activity by tDCS. In opposition to this, hf-tRNS was associated with reduced motor task-related-activity bilaterally in the frontal cortex and precuneous, probably due to interaction with ongoing neuronal oscillations. This result highlights the potential of lf-tRNS and hf-tRNS to differentially modulate visuomotor learning and advances our knowledge on neuroplasticity induction approaches combined with functional imaging methods.

  5. Collaborative activities for improving the quality of science teaching and learning and learning to teach science

    Science.gov (United States)

    Tobin, Kenneth

    2012-03-01

    I have been involved in research on collaborative activities for improving the quality of teaching and learning high school science. Initially the collaborative activities we researched involved the uses of coteaching and cogenerative dialogue in urban middle and high schools in Philadelphia and New York (currently I have active research sites in New York and Brisbane, Australia). The research not only transformed practices but also produced theories that informed the development of additional collaborative activities and served as interventions for research and creation of heuristics for professional development programs and teacher certification courses. The presentation describes a collage of collaborative approaches to teaching and learning science, including coteaching, cogenerative dialogue, radical listening, critical reflection, and mindful action. For each activity in the collage I provide theoretical frameworks and empirical support, ongoing research, and priorities for the road ahead. I also address methodologies used in the research, illustrating how teachers and students collaborated as researchers in multilevel investigations of teaching and learning and learning to teach that included ethnography, video analysis, and sophisticated analyses of the voice, facial expression of emotion, eye gaze, and movement of the body during classroom interactions. I trace the evolution of studies of face-to-face interactions in science classes to the current focus on emotions and physiological aspects of teaching and learning (e.g., pulse rate, pulse strength, breathing patterns) that relate to science participation and achievement.

  6. Measurement of (n,2n) cross-sections for Sc, Mn, Cr and In between 12 and 19 MeV with activation technique

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, S.; Win, Than; Matsuyama, S. [Tohoku Univ., Sendai (Japan). Faculty of Engineering; Odano, N.

    1997-03-01

    Activation cross-sections for scandium, manganese, chromium and indium have been measured in the neutron energies from 12 to 19 MeV. Source neutrons were produced via the T(d,n){sup 4}He reaction by bombarding a 3.2-MeV deuteron beam from the Dynamitron accelerator of Fast Neutron Laboratory at Tohoku University. Ten packages of high or ultra-high purity metal foils for chromium and indium, alloy foils for manganese, and oxide powder for scandium were set around the neutron source at 5 cm from the target in the angular range from 0 to 140 deg covering the incident neutron energies from 19 to 12 MeV at the center position of each package. Activation rates of the samples were obtained by the gamma-ray measurements using a high purity germanium detector. Neutron flux at each sample was determined using the activation rates of two niobium foils locating both sides of that sample; the reference reaction was {sup 93}Nb(n,2n){sup 92m}Nb of which cross-section data was taken from the 1991 NEANDC/INDC standard files. The source neutrons distributions have been measured in detail by the time-of-flight technique. The measured cross-sections are the following important dosimetry or activation reactions: {sup 45}Sc(n,2n){sup 44m}Sc, {sup 55}Mn(n,2n){sup 54}Mn, {sup 52}Cr(n,2n){sup 51}Cr, and {sup 115}In(n,2n){sup 114m}In. These cross-sections are compared with available activation file, dosimetry files and previous experimental data. (author)

  7. Human medial frontal cortex activity predicts learning from errors.

    Science.gov (United States)

    Hester, Robert; Barre, Natalie; Murphy, Kevin; Silk, Tim J; Mattingley, Jason B

    2008-08-01

    Learning from errors is a critical feature of human cognition. It underlies our ability to adapt to changing environmental demands and to tune behavior for optimal performance. The posterior medial frontal cortex (pMFC) has been implicated in the evaluation of errors to control behavior, although it has not previously been shown that activity in this region predicts learning from errors. Using functional magnetic resonance imaging, we examined activity in the pMFC during an associative learning task in which participants had to recall the spatial locations of 2-digit targets and were provided with immediate feedback regarding accuracy. Activity within the pMFC was significantly greater for errors that were subsequently corrected than for errors that were repeated. Moreover, pMFC activity during recall errors predicted future responses (correct vs. incorrect), despite a sizeable interval (on average 70 s) between an error and the next presentation of the same recall probe. Activity within the hippocampus also predicted future performance and correlated with error-feedback-related pMFC activity. A relationship between performance expectations and pMFC activity, in the absence of differing reinforcement value for errors, is consistent with the idea that error-related pMFC activity reflects the extent to which an outcome is "worse than expected."

  8. Public health genetic counselors: activities, skills, and sources of learning.

    Science.gov (United States)

    McWalter, Kirsty M; Sdano, Mallory R; Dave, Gaurav; Powell, Karen P; Callanan, Nancy

    2015-06-01

    Specialization within genetic counseling is apparent, with 29 primary specialties listed in the National Society of Genetic Counselors' 2012 Professional Status Survey (PSS). PSS results show a steady proportion of genetic counselors primarily involved in public health, yet do not identify all those performing public health activities. Little is known about the skills needed to perform activities outside of "traditional" genetic counselor roles and the expertise needed to execute those skills. This study aimed to identify genetic counselors engaging in public health activities, the skills used, and the most influential sources of learning for those skills. Participants (N = 155) reported involvement in several public health categories: (a) Education of Public and/or Health Care Providers (n = 80, 52 %), (b) Population-Based Screening Programs (n = 70, 45 %), (c) Lobbying/Public Policy (n = 62, 40 %), (d) Public Health Related Research (n = 47, 30 %), and (e) State Chronic Disease Programs (n = 12, 8 %). Regardless of category, "on the job" was the most common primary source of learning. Genetic counseling training program was the most common secondary source of learning. Results indicate that the number of genetic counselors performing public health activities is likely higher than PSS reports, and that those who may not consider themselves "public health genetic counselors" do participate in public health activities. Genetic counselors learn a diverse skill set in their training programs; some skills are directly applicable to public health genetics, while other public health skills require additional training and/or knowledge.

  9. Google classroom as a tool for active learning

    Science.gov (United States)

    Shaharanee, Izwan Nizal Mohd; Jamil, Jastini Mohd; Rodzi, Sarah Syamimi Mohamad

    2016-08-01

    As the world is being developed with the new technologies, discovering and manipulating new ideas and concepts of online education are changing rapidly. In response to these changes, many states, institutions, and organizations have been working on strategic plans to implement online education. At the same time, misconceptions and myths related to the difficulty of teaching and learning online, technologies available to support online instruction, the support and compensation needed for high-quality instructors, and the needs of online students create challenges for such vision statements and planning documents. This paper provides analysis and evaluation of the effectiveness of Google Classroom's active learning activities for data mining subject under the Decision Sciences program. Technology Acceptance Model (TAM) has been employed to measure the effectiveness of the learning activities. A total of 100 valid unduplicated responses from students who enrolled data mining subject were used in this study. The results indicated that majority of the students satisfy with the Google Classroom's tool that were introduced in the class. Results of data analyzed showed that all ratios are above averages. In particular, comparative performance is good in the areas of ease of access, perceived usefulness, communication and interaction, instruction delivery and students' satisfaction towards the Google Classroom's active learning activities.

  10. Tunable thermodynamic activity of La x Sr1-x Mn y Al1-y O3-δ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) perovskites for solar thermochemical fuel synthesis.

    Science.gov (United States)

    Ezbiri, M; Takacs, M; Theiler, D; Michalsky, R; Steinfeld, A

    2017-02-28

    Nonstoichiometric metal oxides with variable valence are attractive redox materials for thermochemical and electrochemical fuel processing. To guide the design of advanced redox materials for solar-driven splitting of CO 2 and/or H 2 O to produce CO and/or H 2 (syngas), we investigate the equilibrium thermodynamics of the La x Sr 1- x Mn y Al 1- y O 3- δ perovskite family (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and La 0.6 Ca 0.4 Mn 0.8 Al 0.2 O 3- δ , and compare them to those of CeO 2 as the baseline. Oxygen nonstoichiometry measurements from 1573 to 1773 K and from 0.206 to 180 mbar O 2 show a tunable reduction extent, increasing with increasing Sr content. Maximal nonstoichiometry of 0.32 is established with La 0.2 Sr 0.8 Mn 0.8 Al 0.2 O 3- δ at 1773 K and 2.37 mbar O 2 . As a trend, we find that oxygen capacities are most sensitive to the A-cation composition. Partial molar enthalpy, entropy and Gibbs free energy changes for oxide reduction are extracted from the experimental data using defect models for Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ redox couples. We find that perovskites exhibit typically decreasing enthalpy changes with increasing nonstoichiometries. This desirable characteristic is most pronounced by La 0.6 Sr 0.4 Mn 0.4 Al 0.6 O 3- δ , rendering it attractive for CO 2 and H 2 O splitting. Generally, perovskites show lower enthalpy and entropy changes than ceria, resulting in more favorable reduction but less favorable oxidation equilibria. The energy penalties due to larger temperature swings and excess oxidants are discussed in particular. Using electronic structure theory, we conclude with a practical methodology estimating thermodynamic activity to rationally design perovskites with variable stoichiometry and valence.

  11. Enhancing students' learning in problem based learning: validation of a self-assessment scale for active learning and critical thinking.

    Science.gov (United States)

    Khoiriyah, Umatul; Roberts, Chris; Jorm, Christine; Van der Vleuten, C P M

    2015-08-26

    Problem based learning (PBL) is a powerful learning activity but fidelity to intended models may slip and student engagement wane, negatively impacting learning processes, and outcomes. One potential solution to solve this degradation is by encouraging self-assessment in the PBL tutorial. Self-assessment is a central component of the self-regulation of student learning behaviours. There are few measures to investigate self-assessment relevant to PBL processes. We developed a Self-assessment Scale on Active Learning and Critical Thinking (SSACT) to address this gap. We wished to demonstrated evidence of its validity in the context of PBL by exploring its internal structure. We used a mixed methods approach to scale development. We developed scale items from a qualitative investigation, literature review, and consideration of previous existing tools used for study of the PBL process. Expert review panels evaluated its content; a process of validation subsequently reduced the pool of items. We used structural equation modelling to undertake a confirmatory factor analysis (CFA) of the SSACT and coefficient alpha. The 14 item SSACT consisted of two domains "active learning" and "critical thinking." The factorial validity of SSACT was evidenced by all items loading significantly on their expected factors, a good model fit for the data, and good stability across two independent samples. Each subscale had good internal reliability (>0.8) and strongly correlated with each other. The SSACT has sufficient evidence of its validity to support its use in the PBL process to encourage students to self-assess. The implementation of the SSACT may assist students to improve the quality of their learning in achieving PBL goals such as critical thinking and self-directed learning.

  12. Understanding Insurance. A Guide for Industrial Cooperative Training Programs. Learning Activity Package No. 15.

    Science.gov (United States)

    Duenk, Lester G.; Tuel, Charles

    This learning activity package (LAP) on the insurance industry and the methods used to give protection to the insured is designed for student self-study. Following a list of learning objectives, the LAP contains a pretest (answer key provided at the back). Six learning activities follow. The learning activities cover the following material: terms…

  13. Musical Peddy-Paper: A Collaborative Learning Activity Suported by Augmented Reality

    Science.gov (United States)

    Gomes, José Duarte Cardoso; Figueiredo, Mauro Jorge Guerreiro; Amante, Lúcia da Graça Cruz Domingues; Gomes, Cristina Maria Cardoso

    2014-01-01

    Gaming activities are an integral part of the human learning process, in particular for children. Game-based learning focuses on motivation and children's engagement towards learning. Educational game-based activities are becoming effective strategies to enhance the learning process. This paper presents an educational activity focusing to merge…

  14. An active-learning strategies primer for achieving ability-based educational outcomes.

    Science.gov (United States)

    Gleason, Brenda L; Peeters, Michael J; Resman-Targoff, Beth H; Karr, Samantha; McBane, Sarah; Kelley, Kristi; Thomas, Tyan; Denetclaw, Tina H

    2011-11-10

    Active learning is an important component of pharmacy education. By engaging students in the learning process, they are better able to apply the knowledge they gain. This paper describes evidence supporting the use of active-learning strategies in pharmacy education and also offers strategies for implementing active learning in pharmacy curricula in the classroom and during pharmacy practice experiences.

  15. Active Learning Strategies in Face-to-Face Courses. IDEA Paper #53

    Science.gov (United States)

    Millis, Barbara J.

    2012-01-01

    As numerous research studies suggest, teachers who desire increased student learning should adopt active learning. This article explores the research, defines active learning, discusses its value, offers suggestions for implementing it, and provides six concrete examples of active learning approaches: Thinking-Aloud Pair Problem-Solving;…

  16. Exploring Characteristics of Fine-Grained Behaviors of Learning Mathematics in Tablet-Based E-Learning Activities

    Science.gov (United States)

    Yeung, Cheuk Yu; Shum, Kam Hong; Hui, Lucas Chi Kwong; Chu, Samuel Kai Wah; Chan, Tsing Yun; Kuo, Yung Nin; Ng, Yee Ling

    2017-01-01

    Attributes of teaching and learning contexts provide rich information about how students participate in learning activities. By tracking and analyzing snapshots of these attributes captured continuously throughout the duration of the learning activities, teachers can identify individual students who need special attention and apply different…

  17. The Impact of Peer Review on Creative Self-Efficacy and Learning Performance in Web 2.0 Learning Activities

    Science.gov (United States)

    Liu, Chen-Chung; Lu, Kuan-Hsien; Wu, Leon Yufeng; Tsai, Chin-Chung

    2016-01-01

    Many studies have pointed out the significant contrast between the creative nature of Web 2.0 learning activities and the structured learning in school. This study proposes an approach to leveraging Web 2.0 learning activities and classroom teaching to help students develop both specific knowledge and creativity based on Csikzentmihalyi's system…

  18. The effect of age on Br, Ca, Cl, K, Mg, Mn, and Na mass fraction in pediatric and young adult prostate glands investigated by neutron activation analysis

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Zaichick, Sofia

    2013-01-01

    The effect of age on chemical element mass fractions in intact prostate of 50 apparently healthy 0–30 year old males was investigated by neutron activation analysis with high resolution spectrometry of short-lived radionuclides. Mean values (M±SΕΜ) for mass fraction (mg kg −1 , dry mass basis) of chemical elements before the time of puberty and in the period of puberty and post-puberty were: Br 46.0±6.7, Ca 1151±140, Cl 14572±700, K 10147±700, Mg 771±131, Mn 2.13±0.25, Na 9880±659 and Br 29.0±4.6, Ca 2049±364, Cl 11518±1121, K 13029±542, Mg 1186±134, Mn 1.74±0.16, Na 9887±716, respectively. A tendency of age-related increase in Ca, K, and Mg mass fraction and of age-related decrease in Br mass fraction was observed in period of life from 0 to 30 years. This new data indicates that of the elements studied, only the Ca, K, and Mg mass fraction in prostate tissue is an androgen-dependent parameter

  19. Determination of Cl, K, Mg, Mn, Na and V in Brazilian red wine by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Daniele, Anna Paula; Maihara, Vera Akiko, E-mail: annapaula@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Several studies have been carried out for determining essential elements in foodstuffs due to important nutritional role in human body functions. Such information is crucial to any intervention in the diet of a population, thus becoming representative in the public health field. Trace elements are good indicators of wine’s origin and their concentrations can be used as criteria to ensure authenticity, quality and show that the tolerance limits established by law were respected throughout the production process. Although Brazilian wine industry is among the 15 largest in the world, analytical studies on the content of organic and inorganic compounds in wine are still small compared to other major producers. This study aimed to evaluate the elemental concentration of Cl, K, Mg, Mn, Na and V in seven national red wine samples acquired in the markets of Sao Paulo city. The analytical method applied was INAA. Concentrations of the elements in wine samples showed high variation among samples. (author)

  20. Determination of Cl, K, Mg, Mn, Na and V in Brazilian red wine by neutron activation analysis

    International Nuclear Information System (INIS)

    Daniele, Anna Paula; Maihara, Vera Akiko

    2015-01-01

    Several studies have been carried out for determining essential elements in foodstuffs due to important nutritional role in human body functions. Such information is crucial to any intervention in the diet of a population, thus becoming representative in the public health field. Trace elements are good indicators of wine’s origin and their concentrations can be used as criteria to ensure authenticity, quality and show that the tolerance limits established by law were respected throughout the production process. Although Brazilian wine industry is among the 15 largest in the world, analytical studies on the content of organic and inorganic compounds in wine are still small compared to other major producers. This study aimed to evaluate the elemental concentration of Cl, K, Mg, Mn, Na and V in seven national red wine samples acquired in the markets of Sao Paulo city. The analytical method applied was INAA. Concentrations of the elements in wine samples showed high variation among samples. (author)

  1. Biosorption of Cd, Cr, Mn, and Pb from aqueous solutions by Bacillus sp strains isolated from industrial waste activate sludge

    Directory of Open Access Journals (Sweden)

    Rocío García

    2016-01-01

    Full Text Available Los microorganismos tienen capacidad de acumular metales pesados como agentes bioadsorbentes ofreciendo una alternativa para la remoción de metales tóxicos en aguas de efluentes industriales. El objetivo del presente trabajo fue aislar e identificar bacterias tolerantes a los metales pesados (Cd, Cr, Mn y Pb de lodos activados provenientes de la planta de tratamiento de agua del Municipio de Santa Rosa Jáuregui, Querétaro. Para seleccionar las bacterias que son tolerantes a los metales se aislaron 37 cepas bacterianas de las cuales se seleccionaron la Cepa-13 y Cepa-16 (C-13 y C-16, que presentaron una máxima capacidad de adsorción para los metales estudiados. En este artículo, el término biosorción describe la remoción de contaminantes y la utilización de biomasas (muerta mediante mecanismos fisicoquímicos como el proceso de adsorción o de intercambio iónico. Para obtener las condiciones de máxima adsorción se aplicó un tratamiento alcalino y uno ácido. La capacidad de adsorción fue menor en medio ácido que el bioadsorbente con tratamiento alcalino. Una segunda etapa del estudio fue la biosorción de metales pesados (Cd, Cr, Mn, y Pb utilizando las biomasas muertas de Bacillus sp (cepa C13 y C16 aisladas de los lodos activados de la primera etapa.

  2. Learning Activity Predictors from Sensor Data: Algorithms, Evaluation, and Applications.

    Science.gov (United States)

    Minor, Bryan; Doppa, Janardhan Rao; Cook, Diane J

    2017-12-01

    Recent progress in Internet of Things (IoT) platforms has allowed us to collect large amounts of sensing data. However, there are significant challenges in converting this large-scale sensing data into decisions for real-world applications. Motivated by applications like health monitoring and intervention and home automation we consider a novel problem called Activity Prediction , where the goal is to predict future activity occurrence times from sensor data. In this paper, we make three main contributions. First, we formulate and solve the activity prediction problem in the framework of imitation learning and reduce it to a simple regression learning problem. This approach allows us to leverage powerful regression learners that can reason about the relational structure of the problem with negligible computational overhead. Second, we present several metrics to evaluate activity predictors in the context of real-world applications. Third, we evaluate our approach using real sensor data collected from 24 smart home testbeds. We also embed the learned predictor into a mobile-device-based activity prompter and evaluate the app for 9 participants living in smart homes. Our results indicate that our activity predictor performs better than the baseline methods, and offers a simple approach for predicting activities from sensor data.

  3. Introduction of active learning method in learning physiology by MBBS students.

    Science.gov (United States)

    Gilkar, Suhail Ahmad; Lone, Shabiruddin; Lone, Riyaz Ahmad

    2016-01-01

    Active learning has received considerable attention over the past several years, often presented or perceived as a radical change from traditional instruction methods. Current research on learning indicates that using a variety of teaching strategies in the classroom increases student participation and learning. To introduce active learning methodology, i.e., "jigsaw technique" in undergraduate medical education and assess the student and faculty response to it. This study was carried out in the Department of Physiology in a Medical College of North India. A topic was chosen and taught using one of the active learning methods (ALMs), i.e., jigsaw technique. An instrument (questionnaire) was developed in English through an extensive review of literature and was properly validated. The students were asked to give their response on a five-point Likert scale. The feedback was kept anonymous. Faculty also provided their feedback in a separately provided feedback proforma. The data were collected, compiled, and analyzed. Of 150 students of MBBS-first year batch 2014, 142 participated in this study along with 14 faculty members of the Physiology Department. The majority of the students (>90%) did welcome the introduction of ALM and strongly recommended the use of such methods in teaching many more topics in future. 100% faculty members were of the opinion that many more topics shall be taken up using ALMs. This study establishes the fact that both the medical students and faculty want a change from the traditional way of passive, teacher-centric learning, to the more active teaching-learning techniques.

  4. GeoMapApp Learning Activities: Enabling the democratisation of geoscience learning

    Science.gov (United States)

    Goodwillie, A. M.; Kluge, S.

    2011-12-01

    GeoMapApp Learning Activities (http://serc.carleton.edu/geomapapp) are step-by-step guided inquiry geoscience education activities that enable students to dictate the pace of learning. They can be used in the classroom or out of class, and their guided nature means that the requirement for teacher intervention is minimised which allows students to spend increased time analysing and understanding a broad range of geoscience data, content and concepts. Based upon GeoMapApp (http://www.geomapapp.org), a free, easy-to-use map-based data exploration and visualisation tool, each activity furnishes the educator with an efficient package of downloadable documents. This includes step-by-step student instructions and answer sheet; a teacher's edition annotated worksheet containing teaching tips, additional content and suggestions for further work; quizzes for use before and after the activity to assess learning; and a multimedia tutorial. The activities can be used by anyone at any time in any place with an internet connection. In essence, GeoMapApp Learning Activities provide students with cutting-edge technology, research-quality geoscience data sets, and inquiry-based learning in a virtual lab-like environment. Examples of activities so far created are student calculation and analysis of the rate of seafloor spreading, and present-day evidence on the seafloor for huge ancient landslides around the Hawaiian islands. The activities are designed primarily for students at the community college, high school and introductory undergraduate levels, exposing students to content and concepts typically found in those settings.

  5. A Problem Solving Active-Learning Course in Pharmacotherapy.

    Science.gov (United States)

    Delafuente, Jeffrey C.; And Others

    1994-01-01

    A third-year pharmacology course in a doctoral pharmacy program that is case based and intended for a large class is described. Aspects discussed include learning objectives, course organization, classroom activities, case selection and design, faculty involvement, grading, and areas identified for improvement. (MSE)

  6. Implementing Active Learning Reform in the Maldives: Challenges and Opportunities

    Science.gov (United States)

    Di Biase, Rhonda

    2009-01-01

    Many countries are adopting child-centered active learning reforms as they strive to improve the quality of primary education. Consistent challenges can be found in the implementation of similar, global reforms. These issues are discussed here within the following framework: the cultural appropriateness of such reforms; the extent to which active…

  7. Effect of active learning techniques on students' choice of approach ...

    African Journals Online (AJOL)

    The purpose of this article is to report on empirical work, related to a techniques module, undertaken with the dental students of the University of the Western Cape, South Africa. I will relate how a range of different active learning techniques (tutorials; question papers and mock tests) assisted students to adopt a deep ...

  8. Physical activity during learning inside and outside the classroom

    DEFF Research Database (Denmark)

    Mygind, Erik

    2016-01-01

    Objective: Does learning outside the classroom (LOtC) in urban nature or cultural contexts one day per week contribute to raising children’s physical activity (PA) in lower secondary school? Methods: PA was measured on 7 consecutive days using GT3x+ accelerometers. Overall, 44 girls and 40 boys...

  9. Research and Practice of Active Learning in Engineering Education

    NARCIS (Netherlands)

    Graaf, de Erik; Saunders-Smits, Gillian; Nieweg, Michael

    2005-01-01

    Since 2001, the international network Active Learning in Engineering education (ALE) organized a series of international workshops on innovation of engineering education. The papers in this book are selected to reflect the state of the art, based on contributions to the 2005 ALE workshop in Holland.

  10. Teacher educators' design and implementation of group learning activities

    NARCIS (Netherlands)

    De Hei, Miranda S.A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, J.W.

    2016-01-01

    Group Learning Activities (GLAs) are a key ingredient of course designs in higher education. Various approaches for designing GLAs have been developed, featuring different design components. However, this has not yet resulted in clear guidelines for teachers on how to design GLAs. The purpose of

  11. A Judicious Lesson: A Whole-Learning Reading Activity.

    Science.gov (United States)

    Spooner, Patrick

    2001-01-01

    Describes a unique language learning activity using the whole language approach in a tertiary level lower advanced reading and speaking course. Following a semester long theme on crime and punishment, students were introduced to an authentic, idiomatic text dealing with a famous murder case in U.S. history. (Author/VWL)

  12. An Active Learning Exercise for Introducing Agent-Based Modeling

    Science.gov (United States)

    Pinder, Jonathan P.

    2013-01-01

    Recent developments in agent-based modeling as a method of systems analysis and optimization indicate that students in business analytics need an introduction to the terminology, concepts, and framework of agent-based modeling. This article presents an active learning exercise for MBA students in business analytics that demonstrates agent-based…

  13. Origami: An Active Learning Exercise for Scrum Project Management

    Science.gov (United States)

    Sibona, Christopher; Pourreza, Saba; Hill, Stephen

    2018-01-01

    Scrum is a popular project management model for iterative delivery of software that subscribes to Agile principles. This paper describes an origami active learning exercise to teach the principles of Scrum in management information systems courses. The exercise shows students how Agile methods respond to changes in requirements during project…

  14. The effect of outdoor learning activities on the development of ...

    African Journals Online (AJOL)

    These activities, which provide primary experiences, help children to change theoretical knowledge into practice, record it in the long-term memory, and create solutions to problems they encounter in daily life, based on what they have learned. Children, especially preschoolers, can record things into their long-term memory ...

  15. The Intercollegiate Ethics Bowl: An Active Learning Experience

    Science.gov (United States)

    Meyer, Tracy

    2012-01-01

    This paper introduces the Intercollegiate Ethics Bowl (IEB) as a means of promoting active learning in the realm of marketing ethics. The cases discussed in the competition are based on current ethical issues and require students to provide a coherent analysis of what are generally complex, ambiguous, and highly viewpoint dependent issues. The…

  16. Blog Construction as an Effective Tool in Biochemistry Active Learning

    Science.gov (United States)

    Cubas Rolim, Estêvão; Martins de Oliveira, Julia; Dalvi, Luana T.; Moreira, Daniel C.; Garcia Caldas, Natasha; Fernandes Lobo, Felipe; André Polli, Démerson; Campos, Élida G.; Hermes-Lima, Marcelo

    2017-01-01

    To boost active learning in undergraduate students, they were given the task of preparing blogs on topics of clinical biochemistry. This "experiment" lasted for 12 teaching-semesters (from 2008 to 2013), and included a survey on the blogs' usefulness at the end of each semester. The survey (applied in the 2008-2010 period) used a…

  17. Students’ learning activities while studying biological process diagrams

    NARCIS (Netherlands)

    Kragten, M.; Admiraal, W.; Rijlaarsdam, G.

    2015-01-01

    Process diagrams describe how a system functions (e.g. photosynthesis) and are an important type of representation in Biology education. In the present study, we examined students’ learning activities while studying process diagrams, related to their resulting comprehension of these diagrams. Each

  18. Using an Active-Learning Approach to Teach Epigenetics

    Science.gov (United States)

    Colon-Berlingeri, Migdalisel

    2010-01-01

    Epigenetics involves heritable changes in gene expression that do not involve alterations in the DNA sequence. I developed an active-learning approach to convey this topic to students in a college genetics course. I posted a brief summary of the topic before class to stimulate exchange in cooperative groups. During class, we discussed the…

  19. Development of Active Learning with Simulations and Games

    Science.gov (United States)

    Zapalska, Alina; Brozik, Dallas; Rudd, Denis

    2012-01-01

    Educational games and simulations are excellent active learning tools that offer students hands-on experience. Little research is available on developing games and simulations and how teachers can be assisted in making their own games and simulations. In this context, the paper presents a multi-step process of how to develop games and simulations…

  20. Minority Politics Courses: Moving beyond Controversy and toward Active Learning.

    Science.gov (United States)

    Alex-Assensoh, Yvette

    2000-01-01

    Focuses on an undergraduate course, "Outside Politics: How Minorities Play the Political Game". Describes how to create a foundation for active and collaborative learning and to promote critical thinking, discussion, and writing through reading assignments. Discusses the use of debates and role playing, autobiographies and videos, and…

  1. Active learning and adaptive sampling for non-parametric inference

    NARCIS (Netherlands)

    Castro, R.M.

    2007-01-01

    This thesis presents a general discussion of active learning and adaptive sampling. In many practical scenarios it is possible to use information gleaned from previous observations to focus the sampling process, in the spirit of the "twenty-questions" game. As more samples are collected one can

  2. An example of active learning in Aerospace Engineering

    NARCIS (Netherlands)

    Brugemann, V.P.; Brummelen, van E.H.; Melkert, J.A.; Kamp, A.; Saunders-Smits, G.N.; Reith, B.A.; Zandbergen, B.T.C.; Graaf, de E.; Saunders-Smits, G.N.; Nieweg, M.R.

    2005-01-01

    This paper is a showcase for an on-going active learning capstone design project in the BSe. programme at the Faculty of Aerospace Engineering at Delft University of Technology. In multi-disciplinary teams supervised by tutors from different backgrounds students work towards an Aerospace (related)

  3. Effort and trust: the underpinnings of active learning.

    Science.gov (United States)

    Adams, Seana; Bilimoria, Krish; Malhotra, Neha; Rangachari, P K

    2017-09-01

    Three undergraduate students and their teacher discuss two crucial issues that form the implicit basis of active learning: effort and trust. They use a single course in a Health Sciences Program to anchor their comments. Copyright © 2017 the American Physiological Society.

  4. Creating Student Engagement: The Kickstarter Active Learning Project

    Science.gov (United States)

    Manzon, Elliott

    2017-01-01

    Students can become disengaged from marketing material if they cannot see the direct application. Marketing material needs to be applied to a meaningful business task to engage and motivate students. This article introduces the Kickstarter Active Learning Project--an innovative semester-long project in which students create a Kickstarter…

  5. Active Learning Improves Student Performance in a Respiratory Physiology Lab

    Science.gov (United States)

    Wolf, Alex M.; Liachovitzky, Carlos; Abdullahi, Abass S.

    2015-01-01

    This study assessed the effectiveness of the introduction of active learning exercises into the anatomy and physiology curriculum in a community college setting. Specifically, the incorporation of a spirometry-based respiratory physiology lab resulted in improved student performance in two concepts (respiratory volumes and the hallmarks of…

  6. Active-learning strategies: the use of a game to reinforce learning in nursing education. A case study.

    Science.gov (United States)

    Boctor, Lisa

    2013-03-01

    The majority of nursing students are kinesthetic learners, preferring a hands-on, active approach to education. Research shows that active-learning strategies can increase student learning and satisfaction. This study looks at the use of one active-learning strategy, a Jeopardy-style game, 'Nursopardy', to reinforce Fundamentals of Nursing material, aiding in students' preparation for a standardized final exam. The game was created keeping students varied learning styles and the NCLEX blueprint in mind. The blueprint was used to create 5 categories, with 26 total questions. Student survey results, using a five-point Likert scale showed that they did find this learning method enjoyable and beneficial to learning. More research is recommended regarding learning outcomes, when using active-learning strategies, such as games. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Active Learning to Develop Motor Skills and Teamwork

    Directory of Open Access Journals (Sweden)

    Johanna Lorena Aristizabal-Almanza

    2017-12-01

    Full Text Available This action-research project was conducted to determine how the use of principles of active learning, specifically collaboration, had an effect on psychomotor performance and achievement in teamwork. The research setting included 20 students of first grade from a private school located in Bogota, Colombia. The students were selected through not randomized sampling based on criteria. The methodological process included observation, interviews, and a scale based on standardized tests to measure skills; the latter was applied before and after the intervention. Data analysis was performed using a triangulation of qualitative data, and through comparative analysis of the initial and final student profile for quantitative inputs. The results showed that, after the intervention with collaborative techniques based on action learning, students achieved a positive variation in their performance. Being part of a team positively affected the achievement of the objectives. Systematical reflection on their practices fostered their capacity to identify strengths and weaknesses to build knowledge in interaction with others. Knowledge construction was nurtured based in their previous experiences. Students showed more accountability and self-directed learning behaviors, according to their age. Overall the experience showed the importance of research and innovation in the classroom in order to provide meaningful data, so teachers and researchers can engage in providing learning experiences based in active learning.

  8. Effective, Active Learning Strategies for the Oceanography Classroom

    Science.gov (United States)

    Dmochowski, J. E.; Marinov, I.

    2014-12-01

    A decline in enrollment in STEM fields at the university level has prompted extensive research on alternative ways of teaching and learning science. Inquiry-based learning as well as the related "flipped" or "active" lectures, and similar teaching methods and philosophies have been proposed as more effective ways to disseminate knowledge in science classes than the traditional lecture. We will provide a synopsis of our experiences in implementing some of these practices into our Introductory Oceanography, Global Climate Change, and Ocean Atmosphere Dynamics undergraduate courses at the University of Pennsylvania, with both smaller and larger enrollments. By implementing tools such as at-home modules; computer labs; incorporation of current research; pre- and post-lecture quizzes; reflective, qualitative writing assignments; peer review; and a variety of in-class learning strategies, we aim to increase the science literacy of the student population and help students gain a more comprehensive knowledge of the topic, enhance their critical thinking skills, and correct misconceptions. While implementing these teaching techniques with college students is not without complications, we argue that a blended class that flexibly and creatively accounts for class size and science level improves the learning experience and the acquired knowledge. We will present examples of student assignments and activities as well as describe the lessons we have learned, and propose ideas for moving forward to best utilize innovative teaching tools in order to increase science literacy in oceanography and other climate-related courses.

  9. Cognitive Neurostimulation: Learning to Volitionally Sustain Ventral Tegmental Area Activation.

    Science.gov (United States)

    MacInnes, Jeff J; Dickerson, Kathryn C; Chen, Nan-Kuei; Adcock, R Alison

    2016-03-16

    Activation of the ventral tegmental area (VTA) and mesolimbic networks is essential to motivation, performance, and learning. Humans routinely attempt to motivate themselves, with unclear efficacy or impact on VTA networks. Using fMRI, we found untrained participants' motivational strategies failed to consistently activate VTA. After real-time VTA neurofeedback training, however, participants volitionally induced VTA activation without external aids, relative to baseline, Pre-test, and control groups. VTA self-activation was accompanied by increased mesolimbic network connectivity. Among two comparison groups (no neurofeedback, false neurofeedback) and an alternate neurofeedback group (nucleus accumbens), none sustained activation in target regions of interest nor increased VTA functional connectivity. The results comprise two novel demonstrations: learning and generalization after VTA neurofeedback training and the ability to sustain VTA activation without external reward or reward cues. These findings suggest theoretical alignment of ideas about motivation and midbrain physiology and the potential for generalizable interventions to improve performance and learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Equilibrium constant and nitrogen activity and the parameters of interaction eN(N), rN(N,Cr), rN(N,Mn) in high nitrogen steels of Fe-Cr-Mn-N type

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Siwka, J.; Rashev, T.

    1999-01-01

    In the paper a description of a thermodynamic of liquid solutions of Fe-Cr-Mn-N type with using a concept of parameters of an interaction has been presented. A temperature relationship of the equilibrium constant K N(Fe) and values of self interaction parameters e N (N) , r N (N,Cr) , r N (N,Mn) and t N (N,Cr,Cr) has been determined for mean values of temperatures of liquid metal equal 1990 K and 2090 K. By application of a theory of regular solutions those values were recalculated for a temperature 1873 K. (orig.)

  11. Less is more: Sampling chemical space with active learning

    Science.gov (United States)

    Smith, Justin S.; Nebgen, Ben; Lubbers, Nicholas; Isayev, Olexandr; Roitberg, Adrian E.

    2018-06-01

    The development of accurate and transferable machine learning (ML) potentials for predicting molecular energetics is a challenging task. The process of data generation to train such ML potentials is a task neither well understood nor researched in detail. In this work, we present a fully automated approach for the generation of datasets with the intent of training universal ML potentials. It is based on the concept of active learning (AL) via Query by Committee (QBC), which uses the disagreement between an ensemble of ML potentials to infer the reliability of the ensemble's prediction. QBC allows the presented AL algorithm to automatically sample regions of chemical space where the ML potential fails to accurately predict the potential energy. AL improves the overall fitness of ANAKIN-ME (ANI) deep learning potentials in rigorous test cases by mitigating human biases in deciding what new training data to use. AL also reduces the training set size to a fraction of the data required when using naive random sampling techniques. To provide validation of our AL approach, we develop the COmprehensive Machine-learning Potential (COMP6) benchmark (publicly available on GitHub) which contains a diverse set of organic molecules. Active learning-based ANI potentials outperform the original random sampled ANI-1 potential with only 10% of the data, while the final active learning-based model vastly outperforms ANI-1 on the COMP6 benchmark after training to only 25% of the data. Finally, we show that our proposed AL technique develops a universal ANI potential (ANI-1x) that provides accurate energy and force predictions on the entire COMP6 benchmark. This universal ML potential achieves a level of accuracy on par with the best ML potentials for single molecules or materials, while remaining applicable to the general class of organic molecules composed of the elements CHNO.

  12. Hilar GABAergic Interneuron Activity Controls Spatial Learning and Memory Retrieval

    Science.gov (United States)

    Andrews-Zwilling, Yaisa; Gillespie, Anna K.; Kravitz, Alexxai V.; Nelson, Alexandra B.; Devidze, Nino; Lo, Iris; Yoon, Seo Yeon; Bien-Ly, Nga; Ring, Karen; Zwilling, Daniel; Potter, Gregory B.; Rubenstein, John L. R.; Kreitzer, Anatol C.; Huang, Yadong

    2012-01-01

    Background Although extensive research has demonstrated the importance of excitatory granule neurons in the dentate gyrus of the hippocampus in normal learning and memory and in the pathogenesis of amnesia in Alzheimer's disease (AD), the role of hilar GABAergic inhibitory interneurons, which control the granule neuron activity, remains unclear. Methodology and Principal Findings We explored the function of hilar GABAergic interneurons in spatial learning and memory by inhibiting their activity through Cre-dependent viral expression of enhanced halorhodopsin (eNpHR3.0)—a light-driven chloride pump. Hilar GABAergic interneuron-specific expression of eNpHR3.0 was achieved by bilaterally injecting adeno-associated virus containing a double-floxed inverted open-reading frame encoding eNpHR3.0 into the hilus of the dentate gyrus of mice expressing Cre recombinase under the control of an enhancer specific for GABAergic interneurons. In vitro and in vivo illumination with a yellow laser elicited inhibition of hilar GABAergic interneurons and consequent activation of dentate granule neurons, without affecting pyramidal neurons in the CA3 and CA1 regions of the hippocampus. We found that optogenetic inhibition of hilar GABAergic interneuron activity impaired spatial learning and memory retrieval, without affecting memory retention, as determined in the Morris water maze test. Importantly, optogenetic inhibition of hilar GABAergic interneuron activity did not alter short-term working memory, motor coordination, or exploratory activity. Conclusions and Significance Our findings establish a critical role for hilar GABAergic interneuron activity in controlling spatial learning and memory retrieval and provide evidence for the potential contribution of GABAergic interneuron impairment to the pathogenesis of amnesia in AD. PMID:22792368

  13. Hilar GABAergic interneuron activity controls spatial learning and memory retrieval.

    Directory of Open Access Journals (Sweden)

    Yaisa Andrews-Zwilling

    Full Text Available Although extensive research has demonstrated the importance of excitatory granule neurons in the dentate gyrus of the hippocampus in normal learning and memory and in the pathogenesis of amnesia in Alzheimer's disease (AD, the role of hilar GABAergic inhibitory interneurons, which control the granule neuron activity, remains unclear.We explored the function of hilar GABAergic interneurons in spatial learning and memory by inhibiting their activity through Cre-dependent viral expression of enhanced halorhodopsin (eNpHR3.0--a light-driven chloride pump. Hilar GABAergic interneuron-specific expression of eNpHR3.0 was achieved by bilaterally injecting adeno-associated virus containing a double-floxed inverted open-reading frame encoding eNpHR3.0 into the hilus of the dentate gyrus of mice expressing Cre recombinase under the control of an enhancer specific for GABAergic interneurons. In vitro and in vivo illumination with a yellow laser elicited inhibition of hilar GABAergic interneurons and consequent activation of dentate granule neurons, without affecting pyramidal neurons in the CA3 and CA1 regions of the hippocampus. We found that optogenetic inhibition of hilar GABAergic interneuron activity impaired spatial learning and memory retrieval, without affecting memory retention, as determined in the Morris water maze test. Importantly, optogenetic inhibition of hilar GABAergic interneuron activity did not alter short-term working memory, motor coordination, or exploratory activity.Our findings establish a critical role for hilar GABAergic interneuron activity in controlling spatial learning and memory retrieval and provide evidence for the potential contribution of GABAergic interneuron impairment to the pathogenesis of amnesia in AD.

  14. Problem-based Learning (PBL in Sociolinguistics as a Way of Encouraging Active Learning

    Directory of Open Access Journals (Sweden)

    Engku Ibrahim Engku Haliza

    2018-01-01

    Full Text Available The major concern of this paper is to advocate the integration of PBL strategies in classroom instruction as a way of promoting active learning. It is undoubted that the benefits of problem-based learning (PBL are numerous. In the sciences, PBL has been well integrated in the curriculum. This research reports of an experience of integrating problem-based learning in an introductory Sociolinguistics course for 60 undergraduates of a Bachelors of English programme through a semester that ran for 14 weeks. A focused group interview and questionnaire were used to find out the perceptions of the students undergoing the hybrid PBL course. The findings of this study reveal that students generally enjoyed the PBL approach and found that they had little choice but to become active learners. Some challenges faced by the learners were also highlighted. These findings have implications for the integration of PBL in the field of social sciences.

  15. Predicting Solar Activity Using Machine-Learning Methods

    Science.gov (United States)

    Bobra, M.

    2017-12-01

    Of all the activity observed on the Sun, two of the most energetic events are flares and coronal mass ejections. However, we do not, as of yet, fully understand the physical mechanism that triggers solar eruptions. A machine-learning algorithm, which is favorable in cases where the amount of data is large, is one way to [1] empirically determine the signatures of this mechanism in solar image data and [2] use them to predict solar activity. In this talk, we discuss the application of various machine learning algorithms - specifically, a Support Vector Machine, a sparse linear regression (Lasso), and Convolutional Neural Network - to image data from the photosphere, chromosphere, transition region, and corona taken by instruments aboard the Solar Dynamics Observatory in order to predict solar activity on a variety of time scales. Such an approach may be useful since, at the present time, there are no physical models of flares available for real-time prediction. We discuss our results (Bobra and Couvidat, 2015; Bobra and Ilonidis, 2016; Jonas et al., 2017) as well as other attempts to predict flares using machine-learning (e.g. Ahmed et al., 2013; Nishizuka et al. 2017) and compare these results with the more traditional techniques used by the NOAA Space Weather Prediction Center (Crown, 2012). We also discuss some of the challenges in using machine-learning algorithms for space science applications.

  16. DASL-Data and Activities for Solar Learning

    Science.gov (United States)

    Jones, Harrison P.; Henney, Carl; Hill, Frank; Gearen, Michael; Pompca, Stephen; Stagg, Travis; Stefaniak, Linda; Walker, Connie

    2004-01-01

    DASL-Data and Activities for Solar Learning Data and Activities for Solar Learning (DASL) provides a classroom learning environment based on a twenty-five year record of solar magnetograms from the National Solar Observatory (NSO) at Kitt Peak, AZ. The data, together with image processing software for Macs or PCs, can be used to learn basic facts about the Sun and astronomy at the middle school level. At the high school level, students can study properties of the Sun's magnetic cycle with classroom exercises emphasizing data and error analysis and can participate in a new scientific study, Research in Active Solar Longitudes (RASL), in collaboration with classrooms throughout the country and scientists at NSO and NASA. We present a half-day course to train teachers in the scientific content of the project and its classroom use. We will provide a compact disc with the data and software and will demonstrate software installation and use, classroom exercises, and participation in RASL with computer projection.

  17. Application of active learning modalities to achieve medical genetics competencies and their learning outcome assessments.

    Science.gov (United States)

    Hagiwara, Nobuko

    2017-01-01

    The steadily falling costs of genome sequencing, coupled with the growing number of genetic tests with proven clinical validity, have made the use of genetic testing more common in clinical practice. This development has necessitated nongeneticist physicians, especially primary care physicians, to become more responsible for assessing genetic risks for their patients. Providing undergraduate medical students a solid foundation in genomic medicine, therefore, has become all the more important to ensure the readiness of future physicians in applying genomic medicine to their patient care. In order to further enhance the effectiveness of instructing practical skills in medical genetics, the emphasis of active learning modules in genetics curriculum at medical schools has increased in recent years. This is because of the general acceptance of a better efficacy of active learner-centered pedagogy over passive lecturer-centered pedagogy. However, an objective standard to evaluate students' skill levels in genomic medicine achieved by active learning is currently missing. Recently, entrustable professional activities (EPAs) in genomic medicine have been proposed as a framework for developing physician competencies in genomic medicine. EPAs in genomic medicine provide a convenient guideline for not only developing genomic medicine curriculum but also assessing students' competency levels in practicing genomic medicine. In this review, the efficacy of different types of active learning modules reported for medical genetics curricula is discussed using EPAs in genomic medicine as a common evaluation standard for modules' learning outcomes. The utility of the EPAs in genomic medicine for designing active learning modules in undergraduate medical genetics curricula is also discussed.

  18. Effect of different MnO{sub 2} precursors on the electrochemical properties of spinel LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} cathode active materials for high-voltage lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ye, E-mail: mayetju@tju.edu.cn [Department of Applied Chemistry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin (China); Tang, Haoqing [Department of Applied Chemistry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tang, Zhiyuan, E-mail: zytang46@163.com [Department of Applied Chemistry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin (China); Mao, Wenfeng [Department of Applied Chemistry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Zhang, Xinhe [McNair Technology Company Limited, Dongguan, Guangdong 523700 (China)

    2016-11-15

    Highlights: • Synthesis of spinel LNMO via a facile template method. • The specific morphology of LNMO is closely related to that of MnO{sub 2} precursor. • LNMO using NH{sub 4}HCO{sub 3} as precipitant exhibits superior electrochemical performance. - Abstract: LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} (LNMO) cathode materials with different morphologies are prepared via a facile template method using various MnO{sub 2} precursors. The structures, morphologies and electrochemical properties of the as-prepared LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} samples are tested by various physical and electrochemical methods. The results of characterization show that the spinel LNMO cathode materials have good crystal structure and the MnO{sub 2} precursors have no effect on the final products. Moreover, the specific morphology of LNMO is closely related to that of MnO{sub 2} precursor, and further influence the electrochemical performance. In addition, the LNMO sample using NH{sub 4}HCO{sub 3} as precipitant exhibits excellent rate capability and cyclic stability in all as-prepared samples. Cycled at 0.5 and 1 C, the discharge capacities of LNMO cathode active particles using NH{sub 4}HCO{sub 3} as precipitant are 110.6 and 102.2 after 200 charge–discharge cycles, respectively, which are the largest compared with the LNMO using (NH{sub 4}){sub 2}S{sub 2}O{sub 8} and KMnO{sub 4} as oxidants.

  19. Thermal activation energies and peak temperatures in thermoluminescence of LiF (Mg, Ti) and CaF2:Mn at low temperatures

    International Nuclear Information System (INIS)

    Jain, V.K.; Jahan, M.S.

    1987-01-01

    Low temperature thermoluminescence (TL) of LiF (TLD-100) and CaF 2 :Mn is studied. The TLD-100 is dosimetry grade LiF manufactured by Harshaw-Filtrol Partnership. It is believed that it contains about 200 ppm Mg and 7 ppm Ti as impurities. In each case the glow curve shows several peaks. Some of these peaks are quite strong and develop with dose. Others are weak. Kinetic parameters are calculated for the former using the initial rise method and Chen's modified formula. The two sets of values are found to be different. Some authors have suggested empirical formulae connecting peak temperature, T m , and activation energy, E. The empirical relations are tried for the values of E calculated, as well as those available in literature (for T m above room temperature). It is found that a fairly reasonable relation existed between E and T m . (author)

  20. It takes biking to learn: Physical activity improves learning a second language.

    Science.gov (United States)

    Liu, Fengqin; Sulpizio, Simone; Kornpetpanee, Suchada; Job, Remo

    2017-01-01

    Recent studies have shown that concurrent physical activity enhances learning a completely unfamiliar L2 vocabulary as compared to learning it in a static condition. In this paper we report a study whose aim is twofold: to test for possible positive effects of physical activity when L2 learning has already reached some level of proficiency, and to test whether the assumed better performance when engaged in physical activity is limited to the linguistic level probed at training (i.e. L2 vocabulary tested by means of a Word-Picture Verification task), or whether it extends also to the sentence level (which was tested by means of a Sentence Semantic Judgment Task). The results show that Chinese speakers with basic knowledge of English benefited from physical activity while learning a set of new words. Furthermore, their better performance emerged also at the sentential level, as shown by their performance in a Semantic Judgment task. Finally, an interesting temporal asymmetry between the lexical and the sentential level emerges, with the difference between the experimental and control group emerging from the 1st testing session at the lexical level but after several weeks at the sentential level.

  1. Active Learning through Online Quizzes: Better Learning and Less (Busy) Work

    Science.gov (United States)

    Cook, Brian Robert; Babon, Andrea

    2017-01-01

    Active learning is increasingly promoted within institutions of higher education to assist students develop higher order thinking and link knowledge to meaning. In this paper, the authors evaluate the use of weekly online quizzes based on prescribed preparatory material as a tool to incentivize preparatory reading in order to enable and encourage…

  2. How Technology and Collaboration Promote Formative Feedback: A Role for CSCL Research in Active Learning Interventions

    Science.gov (United States)

    Wu, Sally P. W.; Rau, Martina A.

    2017-01-01

    Recent evidence for the effectiveness of active learning interventions has led educators to advocate for widespread adoption of active learning in undergraduate science, technology, engineering, and mathematics courses. Active learning interventions implement technology and collaboration to engage students actively with the content. Yet, it is…

  3. Spin dynamics of Mn12-acetate in the thermally activated tunneling regime: ac susceptibility and magnetization relaxation

    Science.gov (United States)

    Pohjola, Teemu; Schoeller, Herbert

    2000-12-01

    In this work, we study the spin dynamics of Mn12-acetate molecules in the regime of thermally assisted tunneling. In particular, we describe the system in the presence of a strong transverse magnetic field. Similar to recent experiments, the relaxation time/rate is found to display a series of resonances; their Lorentzian shape is found to stem from the tunneling. The dynamic susceptibility χ(ω) is calculated starting from the microscopic Hamiltonian and the resonant structure manifests itself also in χ(ω). Similar to recent results reported on another molecular magnet, Fe8, we find oscillations of the relaxation rate as a function of the transverse magnetic field when the field is directed along a hard axis of the molecules. This phenomenon is attributed to the interference of the geometrical or Berry phase. We propose susceptibility experiments to be carried out for strong transverse magnetic fields to study these oscillations and for a better resolution of the sharp satellite peaks in the relaxation rates.

  4. Activation and motivation of medical students for learning histoembrylogy.

    Science.gov (United States)

    Stiblar-Martincic, D

    1998-01-01

    The paper described the present learning/teaching activities for the basic subject in the medical curriculum called histoembryology. Various forms of teaching are presented, but a special emphasis is put on computer assisted testing. The leading idea in the teaching activities is to improve the activation and motivation of the students. This goal has been only partly achieved presumably because of insufficient coordination and integration in the curriculum. The plans for further improvements in histoembryology teaching are presented, including the improvements in computer assisted testing.

  5. Active Learning and Self-Regulation Enhance Student Teachers’ Professional Competences

    OpenAIRE

    Virtanen, Päivi; Niemi, Hannele M.; Nevgi, Anne

    2017-01-01

    The study identifies the relationships between active learning, student teachers’ self-regulated learning and professional competences. Further, the aim is to investigate how active learning promotes professional competences of student teachers with different self-regulation profiles. Responses from 422 student teachers to an electronic survey were analysed using statistical methods. It was found that the use of active learning methods, such as goal-oriented and intentional learning as well a...

  6. A Conceptual Framework for Organizing Active Learning Experiences in Biology Instruction

    Science.gov (United States)

    Gardner, Joel; Belland, Brian R.

    2012-01-01

    Introductory biology courses form a cornerstone of undergraduate instruction. However, the predominantly used lecture approach fails to produce higher-order biology learning. Research shows that active learning strategies can increase student learning, yet few biology instructors use all identified active learning strategies. In this paper, we…

  7. Cold and warm white light generation using Zn(PO{sub 3}){sub 2} glasses activated by Ce{sup 3+}, Dy{sup 3+} and Mn{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Caldino, U., E-mail: cald@xanum.uam.mx [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 Mexico, D.F. (Mexico); Alvarez, E. [Departamento de Fisica, Universidad de Sonora (UNISON), Boulevard Luis Encinas y Rosales s/n, Hermosillo, Sonora 83000 (Mexico); Speghini, A.; Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy)

    2012-08-15

    The photoluminescence of zinc metaphosphate glasses activated by Dy{sup 3+}, Ce{sup 3+}/Dy{sup 3+} and Ce{sup 3+}/Dy{sup 3+}/Mn{sup 2+} ions was investigated. Non-radiative energy transfers from Ce{sup 3+} to Dy{sup 3+} and Ce{sup 3+} to Mn{sup 2+} are observed upon 280 nm excitation. The non-radiative nature of these transfers is inferred from the increase in the decay rate of the Ce{sup 3+} emission when the glass is co-doped with Dy{sup 3+} or Dy{sup 3+}/Mn{sup 2+}. It is demonstrated that zinc metaphosphate glasses can generate cold or warm white light emission when they are doped with Ce{sup 3+}/Dy{sup 3+} or Ce{sup 3+}/Dy{sup 3+}/Mn{sup 2+} and pumped at 280 nm (peak emission wavelength of AlGaN-based LEDs). The CIE1931 chromaticity coordinates and color temperature were (0.34, 0.35) and 5250 K for the cold light, and (0.47, 0.43) and 2700 K for the warm light. - Highlights: Black-Right-Pointing-Pointer Non-radiative energy transfer from Ce{sup 3+} to Dy{sup 3+} and Mn{sup 2+} takes place in Zn(PO{sub 3}){sub 2} glasses doped with Ce{sup 3+}/Dy{sup 3+}/Mn{sup 2+}. Black-Right-Pointing-Pointer Zn(PO{sub 3}){sub 2} glasses doped with Ce{sup 3+}/Dy{sup 3+} can generate 5250 K cold white light emission. Black-Right-Pointing-Pointer Zn(PO{sub 3}){sub 2} glasses doped with Ce{sup 3+}/Dy{sup 3+}/Mn{sup 2+} can generate 2700 K warm yellowish orange light emission.

  8. Learning through Debate during Problem-Based Learning: An Active Learning Strategy

    Science.gov (United States)

    Mumtaz, Sadaf; Latif, Rabia

    2017-01-01

    We explored medical student's views and perceptions of a series of debates conducted during problem-based learning (PBL) practiced as a part of the Spiral curriculum at the Imam Abdulrahman Bin Faisal University, Saudi Arabia. A series of debates were employed during PBL sessions for second-year female medical students, over the period 2014-2016.…

  9. Debate preparation/participation: an active, effective learning tool.

    Science.gov (United States)

    Koklanaris, Nikki; MacKenzie, Andrew P; Fino, M Elizabeth; Arslan, Alan A; Seubert, David E

    2008-01-01

    Passive educational techniques (such as lectures) are thought to be less productive than active learning. We examined whether preparing for and participating in a debate would be an effective, active way to learn about a controversial topic. We compared quiz performance in residents who attended a lecture to residents who prepared for/participated in a debate. Twelve residents each participated in one lecture session and one debate session. Learning was evaluated via a quiz. Quizzes were given twice: before the debate/lecture and 1 week after the debate/lecture. Quiz scores were compared using repeated measures analysis of variance, with a p value of debating was given to all participants. There was a statistically significant difference in the pretest mean quiz score between the debate and lecture groups: 78.3% and 52.5%, respectively (p = .02). Similarly, on posttest quizzes, the average debater scored 85.8%, versus 61.7% for the lecture group (p = .003). Although no one in the debate group scored lower on a follow-up quiz, 3 residents in the lecture group did worse on follow-up. When learning about a controversial topic, residents who prepared for/participated in a debate achieved higher quiz scores and were better at retaining information than those who attended a lecture. When faced with teaching a controversial topic, organizing a debate may be more effective than giving a lecture.

  10. Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

    Science.gov (United States)

    Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

    Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

  11. Catalytic Oxidation of NO over MnOx–CeO2 and MnOx–TiO2 Catalysts

    Directory of Open Access Journals (Sweden)

    Xiaolan Zeng

    2016-11-01

    Full Text Available A series of MnOx–CeO2 and MnOx–TiO2 catalysts were prepared by a homogeneous precipitation method and their catalytic activities for the NO oxidation in the absence or presence of SO2 were evaluated. Results show that the optimal molar ratio of Mn/Ce and Mn/Ti are 0.7 and 0.5, respectively. The MnOx–CeO2 catalyst exhibits higher catalytic activity and better resistance to SO2 poisoning than the MnOx–TiO2 catalyst. On the basis of Brunauer–Emmett–Teller (BET, X-ray diffraction (XRD, and scanning transmission electron microscope with mapping (STEM-mapping analyses, it is seen that the MnOx–CeO2 catalyst possesses higher BET surface area and better dispersion of MnOx over the catalyst than MnOx–TiO2 catalyst. X-ray photoelectron spectroscopy (XPS measurements reveal that MnOx–CeO2 catalyst provides the abundance of Mn3+ and more surface adsorbed oxygen, and SO2 might be preferentially adsorbed to the surface of CeO2 to form sulfate species, which provides a protection of MnOx active sites from being poisoned. In contrast, MnOx active sites over the MnOx–TiO2 catalyst are easily and quickly sulfated, leading to rapid deactivation of the catalyst for NO oxidation. Furthermore, temperature programmed desorption with NO and O2 (NO + O2-TPD and in situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS characterizations results show that the MnOx–CeO2 catalyst displays much stronger ability to adsorb NOx than the MnOx–TiO2 catalyst, especially after SO2 poisoning.

  12. Dissociation between active and observational learning from positive and negative feedback in Parkinsonism.

    Science.gov (United States)

    Kobza, Stefan; Ferrea, Stefano; Schnitzler, Alfons; Pollok, Bettina; Südmeyer, Martin; Bellebaum, Christian

    2012-01-01

    Feedback to both actively performed and observed behaviour allows adaptation of future actions. Positive feedback leads to increased activity of dopamine neurons in the substantia nigra, whereas dopamine neuron activity is decreased following negative feedback. Dopamine level reduction in unmedicated Parkinson's Disease patients has been shown to lead to a negative learning bias, i.e. enhanced learning from negative feedback. Recent findings suggest that the neural mechanisms of active and observational learning from feedback might differ, with the striatum playing a less prominent role in observational learning. Therefore, it was hypothesized that unmedicated Parkinson's Disease patients would show a negative learning bias only in active but not in observational learning. In a between-group design, 19 Parkinson's Disease patients and 40 healthy controls engaged in either an active or an observational probabilistic feedback-learning task. For both tasks, transfer phases aimed to assess the bias to learn better from positive or negative feedback. As expected, actively learning patients showed a negative learning bias, whereas controls learned better from positive feedback. In contrast, no difference between patients and controls emerged for observational learning, with both groups showing better learning from positive feedback. These findings add to neural models of reinforcement-learning by suggesting that dopamine-modulated input to the striatum plays a minor role in observational learning from feedback. Future research will have to elucidate the specific neural underpinnings of observational learning.

  13. An Augmented Reality-Based Mobile Learning System to Improve Students' Learning Achievements and Motivations in Natural Science Inquiry Activities

    Science.gov (United States)

    Chiang, Tosti H. C.; Yang, Stephen J. H.; Hwang, Gwo-Jen

    2014-01-01

    In this study, an augmented reality-based mobile learning system is proposed for conducting inquiry-based learning activities. An experiment has been conducted to examine the effectiveness of the proposed approach in terms of learning achievements and motivations. The subjects were 57 fourth graders from two classes taught by the same teacher in…

  14. From Swimming Pool to Collaborative Learning Studio: Pedagogy, Space, and Technology in a Large Active Learning Classroom

    Science.gov (United States)

    Lee, Dabae; Morrone, Anastasia S.; Siering, Greg

    2018-01-01

    To promote student learning and bolster student success, higher education institutions are increasingly creating large active learning classrooms to replace traditional lecture halls. Although there have been many efforts to examine the effects of those classrooms on learning outcomes, there is paucity of research that can inform the design and…

  15. Exploring the Effects of Active Learning on High School Students' Outcomes and Teachers' Perceptions of Biotechnology and Genetics Instruction

    Science.gov (United States)

    Mueller, Ashley L.; Knobloch, Neil A.; Orvis, Kathryn S.

    2015-01-01

    Active learning can engage high school students to learn science, yet there is limited understanding if active learning can help students learn challenging science concepts such as genetics and biotechnology. This quasi-experimental study explored the effects of active learning compared to passive learning regarding high school students'…

  16. [Designing the Annual Meeting and Active Learning System].

    Science.gov (United States)

    Kawamura, Kazumi

    2018-01-01

     At the 10th Annual Meeting of the Japanese Society for Pharmaceutical Palliative Care and Sciences our theme centered on active learning systems where adult learners engage on their own initiative. Many of the participants were pharmacists active in clinical practices. Regardless of their specialized skill-sets, pharmacists are constantly faced with difficult challenges in their daily work. Passive, one-way lectures are one resource for them, but unfortunately such lectures provide limited insights for resolving concrete problems. The present meeting aimed to show participants how to obtain information they need to solve specific real-world problems. This paper summarizes how we planned this year's meeting, including details about the debate symposium, social lunch, and online questionnaires. All these elements had the end goal of enabling learners proactivity to become their own best resource for learning. It is sincerely hoped that the design and execution of this meeting will prove resourceful for future annual meetings.

  17. Active Learning in a Large General Physics Classroom.

    Science.gov (United States)

    Trousil, Rebecca

    2008-04-01

    In 2004, we launched a new calculus-based, introductory physics sequence at Washington University. Designed as an alternative to our traditional lecture-based sequence, the primary objectives for this new course were to actively engage students in the learning process, to significantly strengthen students' conceptual reasoning skills, to help students develop higher level quantitative problem solving skills necessary for analyzing ``real world'' problems, and to integrate modern physics into the curriculum. This talk will describe our approach, using The Six Ideas That Shaped Physics text by Thomas Moore, to creating an active learning environment in large classes as well as share our perspective on key elements for success and challenges that we face in the large class environment.

  18. Study on the application of magnesium oxide adsorptive compound to preconcentrate trace elements (As, Cu, Co, Cr, Hg, Mn, Sb and Zn) in high salt water and neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Giang, Nguyen; Tam, Nguyen Thanh; Phuong Mai, Truong Thi; Ho Tran The Huu [Center for Analytical Techniques, Nuclear Research Institute, Dalat (Viet Nam)

    2007-12-15

    The project presents preconcentration neutron activation analysis techniques for determination of trace metals (As, Co, Cr Cu, Hg, Mn, Sb and Zn) in high salt water by adsorption of trace metals on magnesium oxide. Precipitate is collected on 0.45 {mu}m membrane filters and irradiated in pneumatic rabit system and Lazy Susan facility at flux 5.10{sup 12} n/cm{sup 2}.sec for As, Cu, Mn and 2.10{sup 12} n/cm{sup 2}.sec for Hg, Sb, Cr, Co and Zn. The radioactivities of {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn were measured. {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn radio traces were used to establish optimum conditions and to evaluate the chemical yield. Detection limits of this method are 0.019, 0.006, 0.044, 0.058, 0.021, 0.027, 0.012 and 0.094 {mu}g of As, Co, Cr, Cu, Hg, Mn, Sb and Zn respectively. (author)

  19. Study and application of neutron activation analysis and related methods for determination of content of Na, K, Cu, Co, Mn, Ca, Mg, Fe, P and Zn in a lot of speciality fruits of Vietnam (banana, orange, longan, dragon and mango)

    International Nuclear Information System (INIS)

    Nguyen Van Minh; Le Thi Ngoc Trinh; Le Thai Dung; Ta Thi Tuyet Nhung; Nguyen Dang Khoa; Nguyen Tien Dat; Nguyen Thi Hong Tham; Cao Dong Vu

    2007-01-01

    To study the content of trace elements Na, K, Cu, Co, Mn, Ca, Mg, Fe, P and Zn in the speciality fruits is necessary and very important. We collected the studying samples in four Cities such as: Dalat, NhaTrang, HoChiMinh and BinhDuong. The studying samples are: Banana, Orange, Longan, Dragon and Mango. These samples were dried in the Deepfreezer at -40 o C. We analyzed Na, K, Cu, Co, Mn, Ca, Mg, Fe and Zn by neutron activation analysis (INAA, RNAA) and after irradiation measured total β for P. The studying results were shown in the tables. (author)

  20. Study and application of neutron activation analysis and related methods for determination of content of Na, K, Cu, Co, Mn, Ca, Mg, Fe, P and Zn in a lot of speciality fruits of Vietnam (banana, orange, longan, dragon and mango)

    Energy Technology Data Exchange (ETDEWEB)

    Minh, Nguyen Van; Ngoc Trinh, Le Thi; Dung, Le Thai; Tuyet Nhung, Ta Thi; Khoa, Nguyen Dang; Dat, Nguyen Tien; Hong Tham, Nguyen Thi; Vu, Cao Dong [Center for Analytical Techniques, Nuclear Research Institute, Dalat (Viet Nam)

    2007-12-15

    To study the content of trace elements Na, K, Cu, Co, Mn, Ca, Mg, Fe, P and Zn in the speciality fruits is necessary and very important. We collected the studying samples in four Cities such as: Dalat, NhaTrang, HoChiMinh and BinhDuong. The studying samples are: Banana, Orange, Longan, Dragon and Mango. These samples were dried in the Deepfreezer at -40{sup o}C. We analyzed Na, K, Cu, Co, Mn, Ca, Mg, Fe and Zn by neutron activation analysis (INAA, RNAA) and after irradiation measured total {beta} for P. The studying results were shown in the tables. (author)