WorldWideScience

Sample records for blends

  1. Blended Learning

    NARCIS (Netherlands)

    Van der Baaren, John

    2009-01-01

    Van der Baaren, J. (2009). Blended Learning. Presentation given at the Mini symposium 'Blended Learning the way to go?'. November, 5, 2009, The Hague, The Netherlands: Netherlands Defence Academy (NDLA).

  2. Blended learning

    DEFF Research Database (Denmark)

    Dau, Susanne

    2016-01-01

    of navigating different learning environment. Blended learning is conceptualized as an ecological learning process where sociality, mobility, interactionality, structures, spatiality, identity and emotionality are central dimension affiliated to blended learning as way-finding. Based on the findings......Blended Learning has been implemented, evaluated and researched for the last decades within different educational areas and levels. Blended learning has been coupled with different epistemological understandings and learning theories, but the fundamental character and dimensions of learning...... in blended learning are still insufficient. Moreover, blended learning is a misleading concept described as learning, despite the fact that it fundamentally is an instructional and didactic approach (Oliver & Trigwell, 2005) addressing the learning environment (Inglis, Palipoana, Trenhom & Ward, 2011...

  3. Blended Learning

    Science.gov (United States)

    Imbriale, Ryan

    2013-01-01

    Teachers always have been and always will be the essential element in the classroom. They can create magic inside four walls, but they have never been able to create learning environments outside the classroom like they can today, thanks to blended learning. Blended learning allows students and teachers to break free of the isolation of the…

  4. Blended Learning

    Science.gov (United States)

    Tucker, Catlin; Umphrey, Jan

    2013-01-01

    Catlin Tucker, author of "Blended Learning in Grades 4-12," is an English language arts teacher at Windsor High School in Sonoma County, CA. In this conversation with "Principal Leadership," she defines blended learning as a formal education program in which a student is engaged in active learning in part online where they…

  5. Blended learning

    DEFF Research Database (Denmark)

    Staugaard, Hans Jørgen

    2012-01-01

    Forsøg på at indkredse begrebet blended learning i forbindelse med forberedelsen af projekt FlexVid.......Forsøg på at indkredse begrebet blended learning i forbindelse med forberedelsen af projekt FlexVid....

  6. Blended Learning

    DEFF Research Database (Denmark)

    Gynther, Karsten

    2012-01-01

    Artiklen giver en grundlæggende introduktion til begrebet blended learning og sætter fokus på didaktiske spørgsmål som: Hvad er blended learning? Hvilke forskellige former ser vi i dag i danske uddannelser? Hvorfor udbydes uddannelser i stigende grad i et blended learning format? Hvilke didaktiske...... principper kan man som underviser tage i brug, når man skal designe et blended learning forløb? Hvad er den grundlæggende didaktiske forskel på tilstedeværelsesundervisning og netbaseret undervisning? Og hvilke kritiske perspektiver er det vigtigt at have med, når en uddannelsesinstitution beslutter sig...... for at re-designe traditionel tilstedeværelsesundervisning til blended learning?...

  7. Blended learning

    DEFF Research Database (Denmark)

    Dau, Susanne

    2016-01-01

    in blended learning are still insufficient. Moreover, blended learning is a misleading concept described as learning, despite the fact that it fundamentally is an instructional and didactic approach (Oliver & Trigwell, 2005) addressing the learning environment (Inglis, Palipoana, Trenhom & Ward, 2011......Blended Learning has been implemented, evaluated and researched for the last decades within different educational areas and levels. Blended learning has been coupled with different epistemological understandings and learning theories, but the fundamental character and dimensions of learning......) instead of the learning processes behind. Much of the existing research within the field seems to miss this perspective. The consequence is a lack of acknowledgement of the driven forces behind the context and the instructional design limiting the knowledge foundation of learning in blended learning. Thus...

  8. A Blended Learning Experience

    Science.gov (United States)

    Gecer, Aynur; Dag, Funda

    2012-01-01

    Blended (hybrid) learning is one of the approaches that is utilized to help students for meaningful learning via information and communication technologies in educational settings. In this study, Computer II Course which is taught in faculties of education was planned and implemented in the form of a blended learning environment. The data were…

  9. A Better Blend

    Science.gov (United States)

    Demski, Jennifer

    2010-01-01

    In May 2009, the US Department of Education released a meta-analysis of effectiveness studies of online, face-to-face, and blended learning models. The analysis found that online learning produced better student outcomes than face-to-face classes, and that blended learning offered an even "larger advantage" over face-to-face. The hybrid approach…

  10. Blended Learning Design

    DEFF Research Database (Denmark)

    Pedersen, Lise

    2015-01-01

    University College Lillebaelt has decided that 30 percent of all educational elements must be generated as blended learning by the end of the year 2015 as part of a modernization addressing following educational needs: 1. Blended learning can help match the expectations of the future students who...... have grown up in digitized homes and schools. 2. Blended learning helps individualization and differentiation. The students can organize their own learning paths – decide for themselves where and when to study, which paths to follow and in what tempo. 3. Blended learning helps provide resources...... learning. 4. Blended learning can contribute to supporting and improving efficiency of educational efforts. This can for instance be done through programmes for several classes by using video conferencing, allocating traditional face to face teaching to synchronous and asynchronous study activities produce...

  11. MOOC Blended learning ontwikkelen

    NARCIS (Netherlands)

    Verjans, Steven

    2015-01-01

    Presentatie over het ontwerpen van leeractiviteiten (learning design) tijdens de zesde live sessie van de MOOC Blended learning ontwikkelen. Met gebruikmaking van presentatiematerialen van Diana Laurillard, Grainne Conole, Helen Beetham, Jos Fransen, Pieter Swager, Helen Keegan, Corinne Weisgerber.

  12. Blended Isogeometric Shells

    Science.gov (United States)

    2012-08-01

    engendered by shell intersections, folds, boundary conditions the merging of NURBS patches, etc.We illustrate the blended theory?s performance on a...general and effective treatment of kinematic constraints engendered by shell intersections, folds, boundary con- ditions, the merging of NURBS patches...etc. We illustrate the blended theory’s performance on a series of test problems. Key words: isogeometric analysis, NURBS , shells, rotation-free

  13. Blended Learning Environments and Suggesstions for Blended Learning Design

    Directory of Open Access Journals (Sweden)

    Funda DAĞ

    2011-06-01

    Full Text Available The number of studies in blended learning field, which has gained importance by being reinterpreted with the effect of the developments in information and communication technologies, has been increasing recently. There have been many diverse approaches in these studies on the point of defining blended learning and on the point of which components of blended learning environments need blending and how they are blended. The aim of this study is to examine national and international studies in blended learning in higher education and to make suggestions about necessary components for designing an effective blended learning environment. Within this framework the studies on blended learning, which were accessible online, were examined from the perspectives of research methods that were used, preferred e-learning environments and/or e-learning methods, preferred face to face learning/teaching strategies and the methods used in the evaluation of blended learning. In the light of the findings it is seen that blended learning should be regarded as a teaching design approach in order to create effectively blended learning environments and it is hoped that the suggestions made will be lodestar in forming blended learning models for diverse learning fields.

  14. AKRO/SF: Blend System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Blend was the system used by the NMFS Alaska Regional Office to monitor groundfish catch from 1991 until 2002. The Blend system combined data from industry...

  15. Polymer Blends. Volume 1

    Science.gov (United States)

    1992-05-01

    PBI/ ULTEM NEAT RESIN MOLDING EVALUATIONS 18 2.1.3 85/15 PBI/ ULTEM COMPOSITE EVALUATIONS 22 2.1.4 FIRST GENERATION SUMMARY 26 2.2 IMPROVED PBI/"BEST...PBI 37 2.2.4 85/15 eCPBI-2/ ULTEM NEAT RESIN EVALUATIONS 42 2.2.5 SECOND GENERATION SUMMARY 45 2.3 IMPROVED PBI/6F POLYIMIDE BLENDS: THIRD GENERATION...PYROMELLITIC DIANHYDRIDE 100 A1.2 REVIEW AND RISK ANALYSIS 105 iv FIGURES FIGURE PAGE # I HIGH PERFORMANCE POLYMER BLENDS PLAN 6 2 PBI/ ULTEM SEPARATION

  16. Multi-model blending

    Science.gov (United States)

    Hamann, Hendrik F.; Hwang, Youngdeok; van Kessel, Theodore G.; Khabibrakhmanov, Ildar K.; Muralidhar, Ramachandran

    2016-10-18

    A method and a system to perform multi-model blending are described. The method includes obtaining one or more sets of predictions of historical conditions, the historical conditions corresponding with a time T that is historical in reference to current time, and the one or more sets of predictions of the historical conditions being output by one or more models. The method also includes obtaining actual historical conditions, the actual historical conditions being measured conditions at the time T, assembling a training data set including designating the two or more set of predictions of historical conditions as predictor variables and the actual historical conditions as response variables, and training a machine learning algorithm based on the training data set. The method further includes obtaining a blended model based on the machine learning algorithm.

  17. Blended learning in anatomy

    DEFF Research Database (Denmark)

    Østergaard, Gert Værge; Brogner, Heidi Marie

    2016-01-01

    The aim of the project was to bridge the gap between theory and practice by working more collaboratively, both peer-to-peer and between student and lecturer. Furthermore the aim was to create active learning environments. The methodology of the project is Design-Based Research (DBR). The idea...... in working with the assignments in the classroom."... External assesor, observer and interviewer Based on the different evaluations, the conclusion are that the blended learning approach combined with the ‘flipped classroom’ is a very good way to learn and apply the anatomy, both for the students...... behind DBR is that new knowledge is generated through processes that simultaneously develop, test and improve a design, in this case, an educational design (1) The main principles used in the project is blended learning and flipped learning (2). …"I definitely learn best in practice, but the theory...

  18. Blending Canal Surfaces Based on PH Curves

    Institute of Scientific and Technical Information of China (English)

    Chen-Dong Xu; Fa-Lai Chen

    2005-01-01

    In this paper, a new method for blending two canal surfaces is proposed. The blending surface is itself a generalized canal surface, the spine curve of which is a PH (Pythagorean-Hodograph) curve. The blending surface possesses an attractive property - its representation is rational. The method is extensible to blend general surfaces as long as the blending boundaries are well-defined.

  19. Blended Learning in English Literature

    OpenAIRE

    Haugestad, Astrid

    2015-01-01

    Abstract Blended Learning This study investigates blended learning used in a course of English Literature and Culture in upper secondary school. It raises the question how the use of blended learning may promote and encourage learning in a course of English literature and culture. The study also compares traditional face-to-face classroom communication with communication mediated by digital artefacts. It has been important to go beyond the strictly technical issues ...

  20. Blended-Learning-Projekte im Unternehmen

    OpenAIRE

    Keller, Miriam; Back, Andrea

    2004-01-01

    Der Arbeitsbericht Blended-Learning-Projekte im Unternehmen liefert einen Beitrag zur Bearbeitung des Themas Blended Learning und liefert dem Leser einen Überblick und erste Anregungen zur Planung, Integration und Gestaltung von Blended-Learning-Konzepten im Unternehmen.

  1. Managing as blended care.

    Science.gov (United States)

    Mintzberg, H

    1994-09-01

    As part of a research project on managerial work based on a new model of the roles, the head nurse of a hospital unit was observed during a working day. Her work is described, with reference especially to the roles of leading, linking, controlling, and doing. Conclusions are drawn about the advantages of a craft style of management as opposed to the more traditional "boss" or professional styles. The author also discusses what those in general management can learn from those in nursing management, which seems best practiced out in the open, on one's feet, as a kind of blended care.

  2. Blended Learning on Campus

    DEFF Research Database (Denmark)

    Heilesen, Simon; Nielsen, Jørgen Lerche

    2004-01-01

    On the basis of a large-scale project implementing information and communication technology at Roskilde University, Denmark, this paper discusses ways of introducing technology-based blended learning in academic life. We examine some examples of use of systems for computer-mediated collabora......-tive learning and work in Danish Open University education as well as in courses on campus. We further suggest some possi-bilities for using technology in innovative ways, arguing that innovation is to be found, not in isolated instantiations of sys-tems, but in the form of a deliberate integration of all...... relevant ICT-features as a whole into the learning environment....

  3. Survey design for blended acquisition

    NARCIS (Netherlands)

    Blacquière, G.; Berkhout, A.J.; Verschuur, D.J.

    2009-01-01

    When designing an acquisition geometry for the case of source blending, it is important that the blended source arrays are capable of transmitting a wavefield with a large spatial and temporal bandwidth: the wavefield must be incoherent. We call this incoherent shooting. Furthermore, the array must

  4. Short fiber reinforced thermoplastic blends

    NARCIS (Netherlands)

    Malchev, P.G.

    2008-01-01

    The present thesis investigates the potential of short fiber reinforced thermoplastic blends, a combination of an immiscible polymer blend and a short fiber reinforced composite, to integrate the easy processing solutions available for short fiber reinforced composites with the high mechanical perfo

  5. The Basics of Blended Instruction

    Science.gov (United States)

    Tucker, Catlin R.

    2013-01-01

    Even though many of teachers do not have technology-rich classrooms, the rapidly evolving education landscape increasingly requires them to incorporate technology to customize student learning. Blended learning, with its mix of technology and traditional face-to-face instruction, is a great approach. Blended learning combines classroom learning…

  6. Blended Learning: An Innovative Approach

    Science.gov (United States)

    Lalima; Dangwal, Kiran Lata

    2017-01-01

    Blended learning is an innovative concept that embraces the advantages of both traditional teaching in the classroom and ICT supported learning including both offline learning and online learning. It has scope for collaborative learning; constructive learning and computer assisted learning (CAI). Blended learning needs rigorous efforts, right…

  7. Blended Learning: A Dangerous Idea?

    Science.gov (United States)

    Moskal, Patsy; Dziuban, Charles; Hartman, Joel

    2013-01-01

    The authors make the case that implementation of a successful blended learning program requires alignment of institutional, faculty, and student goals. Reliable and robust infrastructure must be in place to support students and faculty. Continuous evaluation can effectively track the impact of blended learning on students, faculty, and the…

  8. Classifying K-12 Blended Learning

    Science.gov (United States)

    Staker, Heather; Horn, Michael B.

    2012-01-01

    The growth of online learning in the K-12 sector is occurring both remotely through virtual schools and on campuses through blended learning. In emerging fields, definitions are important because they create a shared language that enables people to talk about the new phenomena. The blended-learning taxonomy and definitions presented in this paper…

  9. Blended Learning Improves Science Education.

    Science.gov (United States)

    Stockwell, Brent R; Stockwell, Melissa S; Cennamo, Michael; Jiang, Elise

    2015-08-27

    Blended learning is an emerging paradigm for science education but has not been rigorously assessed. We performed a randomized controlled trial of blended learning. We found that in-class problem solving improved exam performance, and video assignments increased attendance and satisfaction. This validates a new model for science communication and education.

  10. Blend or not to blend: a study investigating faculty members perceptions of blended teaching

    Directory of Open Access Journals (Sweden)

    Mehmet A Ocak

    2010-12-01

    Full Text Available This study examined faculty members’ perceptions of blended teaching from several perspectives. A total of 73 faculty members in Turkish Higher Education context participated in the study by completing an online survey that combined quantitative and qualitative approaches. Based on a data analysis, the faculty members’ perceptions were sorted into six categories: (a satisfaction with blended teaching, (b perceived impact on the role of the faculty, (c perceived impact on student learning, (d perceived impact on student motivation, (e advantages of blended teaching, and (f disadvantages of blended teaching. Findings indicated that faculty members were likely to agree that blended teaching provides a high degree of satisfaction and that it requires more time and commitment from the faculty. The faculty members perceived that blended teaching improves student learning and, to some extent, improves motivation. The faculty members also emphasized the importance of institutional support and the use of technology to mitigate student problems. This study presents these faculty members’ perceptions, which are helpful for those planning to implement a blended teaching approach, and makes suggestions for trouble-shooting and taking advantage of the opportunities in a blended environment successfully.

  11. Blends of zein and nylon-6

    Science.gov (United States)

    Blends of zein and nylon-6(55k)were used to produce solution cast films and electrospun fibers. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measurement...

  12. Polyamide blend-based nanocomposites: A review

    Directory of Open Access Journals (Sweden)

    W. S. Chow

    2015-03-01

    Full Text Available Polymer blend nanocomposites have been considered as a stimulating route for creating a new type of high performance material that combines the advantages of polymer blends and the merits of polymer nanocomposites. In nanocomposites with multiphase matrices, the concept of using nanofillers to improve select properties (e.g., mechanical, thermal, chemical, etc of a polymer blend, as well as to modify and stabilize the blend morphology has received a great deal of interest. This review reports recent advances in the field of polyamide (PA blend-based nanocomposites. Emphasis is placed on the PA-rich blends produced by blending with other thermoplastics in the presence of nanofillers. The processing and properties of PA blend-based nanocomposites with nanofillers are discussed. In addition, the mechanical properties and morphology changes of PA blends with the incorporation of nanofillers are described. The issues of compatibility and toughening of PA blend nanocomposites are discussed, and current challenges are highlighted.

  13. Performance of Blended Learning in University Teaching:

    Directory of Open Access Journals (Sweden)

    Michael Reiss

    2010-07-01

    Full Text Available Blended learning as a combination of classroom teaching and e-learning has become a widely represented standard in employee and management development of companies. The exploratory survey “Blended Learning@University” conducted in 2008 investigated the integration of blended learning in higher education. The results of the survey show that the majority of participating academic teachers use blended learning in single courses, but not as a program of study and thus do not exploit the core performance potential of blended learning. According to the study, the main driver of blended learning performance is its embeddedness in higher education. Integrated blended programs of study deliver the best results. In blended learning, learning infrastructure (in terms of software, culture, skills, funding, content providing, etc. does not play the role of a performance driver but serves as an enabler for blended learning.

  14. Wavelet and Blend maps for texture synthesis

    Directory of Open Access Journals (Sweden)

    Du Jin-Lian

    2011-04-01

    Full Text Available blending is now a popular technology for large realtime texture synthesis .Nevertheless, creating blend map during rendering is time and computation consuming work. In this paper, we exploited a method to create a kind of blend tile which can be tile together seamlessly. Note that blend map is in fact a kind of image, which is Markov Random Field, contains multiresolution signals, while wavelet is a powerful way to process multiresolution signals, we use wavelet to process the traditional blend tile. After our processing steps, the result blend tile become smooth and suitable for tiling, with no important features lost. Using this kind blend tile, many computation resources for computing blend map during texture synthesizing is saved. The experimental results shows that our method may successfully process many traditional blend tiles.

  15. NURBS curve blending using extension

    Institute of Scientific and Technical Information of China (English)

    Yong-jin LIU; Rong-qi QIU; Xiao-hui LIANG

    2009-01-01

    Curve and surface blending is an important operation in CAD systems, in which a non-uniform rational B-spline (NURBS) has been used as the de facto standard. In local comer blending, two curves intersecting at that comer are first made disjoint, and then the third blending curve is added-in to smoothly join the two curves with G1-or G2-continuity. In this paper we present a study to solve the joint problem based on curve extension. The following nice properties of this extension algorithm are exploited in depth: (1) The parameterization of the original shapes does not change; (2) No additional fragments are created.Various examples are presented to demonstrate that our solution is simple and efficient.

  16. Production of Silk & Wool Blended Worsted Cloth

    Institute of Scientific and Technical Information of China (English)

    段亚峰; 许琳

    2004-01-01

    Wool & silk blended fancy suiting is desinged. Through trial-production with silk sliver and Australian wool top, the spinning technology is investigated, and the relationship of spinning technology, blending ratio and yam construction is discussed.

  17. NESDIS Blended Rain Rate (RR) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Rain Rate (RR) product is derived from multiple sensors/satellites. The blended products were merged from polar-orbiting and geostationary satellite...

  18. Blended Learning as Transformational Institutional Learning

    Science.gov (United States)

    VanDerLinden, Kim

    2014-01-01

    This chapter reviews institutional approaches to blended learning and the ways in which institutions support faculty in the intentional redesign of courses to produce optimal learning. The chapter positions blended learning as a strategic opportunity to engage in organizational learning.

  19. Blended Identities: Identity Work, Equity and Marginalization in Blended Learning

    Science.gov (United States)

    Heikoop, Will

    2013-01-01

    This article is a theoretical study of the self-presentation strategies employed by higher education students online; it examines student identity work via profile information and avatars in a blended learning environment delivered through social networking sites and virtual worlds. It argues that students are faced with difficult choices when…

  20. 7 CFR 989.16 - Blend.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Blend. 989.16 Section 989.16 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... CALIFORNIA Order Regulating Handling Definitions § 989.16 Blend. Blend means to mix or commingle raisins....

  1. Radiation effects on LDPE/EVA blends

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, Jamaliah; Aziz, S.H.S.A.Sharifah Hanisah Syed Abdul; Hashim, Kamaruddin

    2000-04-01

    The effect of radiation on the properties of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) blends were investigated. The improvement of the measured gel content, thermal elongation, tensile strength, elongation at break and heat deformation of the blends have confirmed the positive effect of electron beam irradiation on the blends.

  2. Building a Blended Learning Program

    Science.gov (United States)

    McLester, Susan

    2011-01-01

    "Online learning" often serves as an umbrella term that includes the subcategory of blended learning, which might also be referred to as hybrid learning, and comprises some combination of online and face-to-face time. Spurred in part by a 2009 U.S. Department of Education study, "Evaluation of Evidence-Based Practices in Online Learning," which…

  3. Improvement of biodiesel methanol blends

    Directory of Open Access Journals (Sweden)

    Y. Datta Bharadwaz

    2016-06-01

    Full Text Available The main objective of this work was to improve the performance of biodiesel–methanol blends in a VCR engine by using optimized engine parameters. For optimization of the engine, operational parameters such as compression ratio, fuel blend, and load are taken as factors, whereas performance parameters such as brake thermal efficiency (Bth and brake specific fuel consumption (Bsfc and emission parameters such as carbon monoxide (CO, unburnt hydrocarbons (HC, Nitric oxides (NOx and smoke are taken as responses. Experimentation is carried out as per the design of experiments of the response surface methodology. Optimization of engine operational parameters is carried out using Derringers Desirability approach. From the results obtained it is inferred that the VCR engine has maximum performance and minimum emissions at 18 compression ratio, 5% fuel blend and at 9.03 kg of load. At this optimized operating conditions of the engine the responses such as brake thermal efficiency, brake specific fuel consumption, carbon monoxide, unburnt hydrocarbons, nitric oxide, and smoke are found to be 31.95%, 0.37 kg/kW h, 0.036%, 5 ppm, 531.23 ppm and 15.35% respectively. It is finally observed from the mathematical models and experimental data that biodiesel methanol blends have maximum efficiency and minimum emissions at optimized engine parameters.

  4. Netbaserede uddannelser og blended learning

    DEFF Research Database (Denmark)

    Bertelsen, Jesper Vedel; Vognsgaard Hjernø, Henriette; Jensen, Michael Peter

    2016-01-01

    Denne håndbog er tænkt som inspiration til uddannelsesfaglige medarbejdere, som er eller skal i gang med at undervise på en netbaseret uddannelse i UCL. Håndbogen giver et teoretisk overblik i forhold til netbaserede uddannelser, online- og blended learning samt en indførsel i hvilke didaktiske...

  5. Study on combustion characteristics of blended coals

    Energy Technology Data Exchange (ETDEWEB)

    Li Yonghua; Wang Chunbo; Chen Hongwei [North China Electric Power University, Baoding (China)

    2007-02-15

    Power plants in China have to burn blended coal instead of one specific coal for a variety of reasons. So it is of great necessity to investigate the combustion of blended coals. Using a test rig with a capacity of 640 MJ/h with an absolute milling system and flue gas online analysis system, characteristics such as burnout, slag, and pollution of some blended coals were investigated. The ratio of coke and slag as a method of distinguishing coal slagging characteristic was introduced. The results show that the blending of coal has some effect on NOx but there is no obvious rule. SOx emission can be reduced by blending low sulfur coal.

  6. SCATTERING FUNCTION OF POLYMER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Lin-ping Ke; Mei-li Guo; De-lu Zhao

    2004-01-01

    For a system of flexible polymer molecules, the concepts of two concentrations, namely the segmental and the molecular concentrations, have been proposed in this paper. The former is equivalent to the volume fraction. The latter can be defined as the number of the gravity centers of macromolecules in a unit volume. The two concentrations should be correlated with each other by the conformational function of the polymer chain and should be discussed in different thermodynamic equations. On the basis of these concepts it has been proved that the Flory-Huggins entropy of mixing should be the result of the mixing "ideal gases of the gravity centers of macromolecules". The general correlation between the free energy of mixing and the scattering function (structural factor) of polymer blends has been studied based on the general fluctuation theory. When the Flory-Huggins free energy of mixing is adopted, the de Gennes scattering function of a polymer blend can be derived.

  7. Evaporation characteristics of ETBE-blended gasoline.

    Science.gov (United States)

    Okamoto, Katsuhiro; Hiramatsu, Muneyuki; Hino, Tomonori; Otake, Takuma; Okamoto, Takashi; Miyamoto, Hiroki; Honma, Masakatsu; Watanabe, Norimichi

    2015-04-28

    To reduce greenhouse gas emissions, which contribute to global warming, production of gasoline blended with ethyl tert-buthyl ether (ETBE) is increasing annually. The flash point of ETBE is higher than that of gasoline, and blending ETBE into gasoline will change the flash point and the vapor pressure. Therefore, it is expected that the fire hazard caused by ETBE-blended gasoline would differ from that caused by normal gasoline. The aim of this study was to acquire the knowledge required for estimating the fire hazard of ETBE-blended gasoline. Supposing that ETBE-blended gasoline was a two-component mixture of gasoline and ETBE, we developed a prediction model that describes the vapor pressure and flash point of ETBE-blended gasoline in an arbitrary ETBE blending ratio. We chose 8-component hydrocarbon mixture as a model gasoline, and defined the relation between molar mass of gasoline and mass loss fraction. We measured the changes in the vapor pressure and flash point of gasoline by blending ETBE and evaporation, and compared the predicted values with the measured values in order to verify the prediction model. The calculated values of vapor pressures and flash points corresponded well to the measured values. Thus, we confirmed that the change in the evaporation characteristics of ETBE-blended gasoline by evaporation could be predicted by the proposed model. Furthermore, the vapor pressure constants of ETBE-blended gasoline were obtained by the model, and then the distillation curves were developed.

  8. Game innovation through conceptual blending

    DEFF Research Database (Denmark)

    Möring, Sebastian Martin

    In  this  paper  I  wish  to  apply implications of  the  Conceptual  Blending  Theory  to  computer  games.  I  will  analyze  chosen  examples  and  discuss  them  as  a  result  of  video  game  innovation  made  possible  through  "conceptual  blending."  Conceptual  blending  links  at  least.......,  Hell.  The  purpose  of  my  approach  is  not  so  much  to  validate  the  ideas  of  conceptual  blending  theory  through  another  field  of  examples  (computer  games)  but  to  name  and analyze characteristics of the mentioned games with the  help of a given method.......  integration  network  consisting  of  at  least  two  input  spaces,  a  generic  space  and  a  blended  space  as  well  as  its  governing  principles  consisting  of  composition,  completion,  and  elaboration.  With  the  help  of  these  instruments  I  analyze computer  games like  Tuper  Tario  Tros...

  9. Correspondence Theory and Phonological Blending in French

    Directory of Open Access Journals (Sweden)

    Lee Scott

    2014-07-01

    Full Text Available Though less productive than rival word-formation processes like compounding and affixation, blending is still a rich source of neologisms in French. Despite this productivity, however, blends are often seen by scholars as unpredictable, uninteresting, or both. This analysis picks up where recent studies of blending have left off, using Correspondence Theory and a bundle of segmental constraints to deal with this phenomenon as it pertains to French. More specifically, it shows that blending is the result of a single output standing in correspondence with two or more other outputs, and that we do not need to refer to prosodic information, which is crucial in accounts of blending in languages with lexical stress like English, to account for the process in French. The analysis also differs from previous studies in that it locates blending exclusively within the phonology, leaving its morphological and semantic characteristics to be handled by other processes in the grammar.

  10. Statistical methods for assessment of blend homogeneity

    DEFF Research Database (Denmark)

    Madsen, Camilla

    2002-01-01

    In this thesis the use of various statistical methods to address some of the problems related to assessment of the homogeneity of powder blends in tablet production is discussed. It is not straight forward to assess the homogeneity of a powder blend. The reason is partly that in bulk materials...... as powder blends there is no natural unit or amount to define a sample from the blend, and partly that current technology does not provide a method of universally collecting small representative samples from large static powder beds. In the thesis a number of methods to assess (in)homogeneity are presented....... Some methods have a focus on exploratory analysis where the aim is to investigate the spatial distribution of drug content in the batch. Other methods presented focus on describing the overall (total) (in)homogeneity of the blend. The overall (in)homogeneity of the blend is relevant as it is closely...

  11. Evaporation characteristics of ETBE-blended gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Katsuhiro, E-mail: okamoto@nrips.go.jp [National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882 (Japan); Hiramatsu, Muneyuki [Yamanashi Prefectural Police H.Q., 312-4 Kubonakajima, Isawa-cho, Usui, Yamanashi 406-0036 (Japan); Hino, Tomonori; Otake, Takuma [Metropolitan Police Department, 2-1-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8929 (Japan); Okamoto, Takashi; Miyamoto, Hiroki; Honma, Masakatsu; Watanabe, Norimichi [National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882 (Japan)

    2015-04-28

    Highlights: • We chose 8-component hydrocarbon mixture as a model gasoline, and defined the molar mass of gasoline. • We proposed an evaporation model assuming a 2-component mixture of gasoline and ETBE. • We predicted the change in the vapor pressure of ETBE-blended gasoline by evaporation. • The vapor pressures were measured and compared as a means of verifying the model. • We presented the method for predicting flash points of the ETBE-blended gasoline. - Abstract: To reduce greenhouse gas emissions, which contribute to global warming, production of gasoline blended with ethyl tert-buthyl ether (ETBE) is increasing annually. The flash point of ETBE is higher than that of gasoline, and blending ETBE into gasoline will change the flash point and the vapor pressure. Therefore, it is expected that the fire hazard caused by ETBE-blended gasoline would differ from that caused by normal gasoline. The aim of this study was to acquire the knowledge required for estimating the fire hazard of ETBE-blended gasoline. Supposing that ETBE-blended gasoline was a two-component mixture of gasoline and ETBE, we developed a prediction model that describes the vapor pressure and flash point of ETBE-blended gasoline in an arbitrary ETBE blending ratio. We chose 8-component hydrocarbon mixture as a model gasoline, and defined the relation between molar mass of gasoline and mass loss fraction. We measured the changes in the vapor pressure and flash point of gasoline by blending ETBE and evaporation, and compared the predicted values with the measured values in order to verify the prediction model. The calculated values of vapor pressures and flash points corresponded well to the measured values. Thus, we confirmed that the change in the evaporation characteristics of ETBE-blended gasoline by evaporation could be predicted by the proposed model. Furthermore, the vapor pressure constants of ETBE-blended gasoline were obtained by the model, and then the distillation curves were

  12. THE COMBUSTION CHARACTERISTICS OF LIGNITE BLENDS

    Institute of Scientific and Technical Information of China (English)

    Cheng Jun; Zhou Junhu; Cao Xinyu; Cen Kefa

    2000-01-01

    The combustion characteristics of lignite blends were studied with a thermogravimetric analyzer (t.g.a.), at constant heating rate.The characteristic temperatures were determined from the burning profiles.It was found that the characteristic times of combustion reaction moved forward, the ignition temperature dropped and the burnout efficiency slightly changed when blending lignites.The characteristic parameters of blends could not be predicted as a linear function of the average values of the individual lignites.when blending with less reactive coal, the ignition and burnout characteristics of lignite turned worse.

  13. Structuring of Interface-Modified Polymer Blends

    DEFF Research Database (Denmark)

    Lyngaae-Jørgensen, Jørgen

    1999-01-01

    The paper treats the case where blends of polystyrene (PS), poly (dimethylsiloxane) (PDMS) and a diblock copolymer of PS and PDMS are used as model materials. This modelsystem is predicted to be "stable" in discrete blends in simple shear flow. Stable in the sence that the block copolymer can not...

  14. Introducing blended e-learning course design

    DEFF Research Database (Denmark)

    Gyamfi, Samuel Adu; Ryberg, Thomas

    2012-01-01

    In the face of diminishing education budgets in higher education, blended learning has been found to be a viable and effective approach to deliver high-quality, up-to-date, on-demand solutions to developing cross-curricular skills of undergraduates. However, research has also shown that blended l...

  15. Storage studies on mustard oil blends.

    Science.gov (United States)

    Chugh, Bhawna; Dhawan, Kamal

    2014-04-01

    Mustard oil blends were investigated for fatty acid composition and oxidative stability during storage for 3 months at room temperature (15 °C to 35 °C). The blends were prepared using raw mustard oil with selected refined vegetable oils namely; palm, safflower, soybean, rice bran, sunflower and sesame oil (raw). The fatty acid compositions of all these blends were studied using GLC. The developed blends were found to obey the ideal fatty acid ratio as laid down by health agencies i.e. 1:2:1:: SFA:MUFA:PUFA. The oxidative stability of blends was studied by measuring peroxide value (PV), Kries and Thiobarbituric acid (TBA) test. Blends MPSu (mustard oil, palm oil and sunflower oil), MPT (mustard oil, palm oil and sesame oil) and MPGr (mustard oil, palm oil and groundnut oil) were more stable than other blends during storage. The presence of mustard oil in all blends might make them a healthier option for many consumers as it is a rich source of ω-3 fatty acids and has anti-carcinogenic properties.

  16. Enhancing Students' Language Skills through Blended Learning

    Science.gov (United States)

    Banditvilai, Choosri

    2016-01-01

    This paper presents a case study of using blended learning to enhance students' language skills and learner autonomy in an Asian university environment. Blended learning represents an educational environment for much of the world where computers and the Internet are readily available. It combines self-study with valuable face-to-face interaction…

  17. PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW)

    Energy Technology Data Exchange (ETDEWEB)

    CERTA, P.J.

    2006-02-22

    The primary objective of this study is to demonstrate a mission scenario that uses pairwise and incidental blending of high level waste (HLW) to reduce the total mass of HLW glass. Secondary objectives include understanding how recent refinements to the tank waste inventory and solubility assumptions affect the mass of HLW glass and how logistical constraints may affect the efficacy of HLW blending.

  18. Blended Learning in Personalized Assistive Learning Environments

    Science.gov (United States)

    Marinagi, Catherine; Skourlas, Christos

    2013-01-01

    In this paper, the special needs/requirements of disabled students and cost-benefits for applying blended learning in Personalized Educational Learning Environments (PELE) in Higher Education are studied. The authors describe how blended learning can form an attractive and helpful framework for assisting Deaf and Hard-of-Hearing (D-HH) students to…

  19. Improving Curriculum through Blended Learning Pedagogy

    Science.gov (United States)

    Darojat, Ojat

    2016-01-01

    This paper is a study of blended learning pedagogy in open and distance learning (ODL), involving two universities in Southeast Asia, STOU Thailand and UT Indonesia. The purpose of this study is to understand the issues related to the implementation of blended-learning pedagogy. Qualitative case study was employed to optimize my understanding of…

  20. Preparing Teachers for Emerging Blended Learning Environments

    Science.gov (United States)

    Oliver, Kevin M.; Stallings, Dallas T.

    2014-01-01

    Blended learning environments that merge learning strategies, resources, and modes have been implemented in higher education settings for nearly two decades, and research has identified many positive effects. More recently, K-12 traditional and charter schools have begun to experiment with blended learning, but to date, research on the effects of…

  1. A Review on Conceptual Blending Theory

    Institute of Scientific and Technical Information of China (English)

    刘丽

    2010-01-01

    The CBT(Conceptual Blending Theory)is rapidly emerging as a major force in cognitive science and provides a unifying umbrella framework for a range of cognitive phenomena.The present paper is to have a general review of the conceptual blending theory through illustrating its four-space theory in order to have a better comprehension of its nature.

  2. Compatibilizing Bulk Polymer Blends by using Organoclays

    Energy Technology Data Exchange (ETDEWEB)

    Si, Mayu; Araki, Tohru; Ade, Harald; Kilcoyne, A.L.D.; Fischer,Robert; Sokolov, Jonathan C.; Rafailovich, Miriam H.

    2006-03-28

    We have studied the morphology of blends of PS/PMMA,PC/SAN24, and PMMA/EVA and compared the morphologies with and withoutmodified organoclay Cloisite 20A or Cloisite 6A clays. In each case wefound a large reduction in domains size and the localization of the clayplatelets along the interfaces of the components. The increasedmiscibility was accompanied in some cases, with the reduction of thesystem from multiple values of the glass transition temperatures to one.In addition, the modulus of all the systems increased significantly. Amodel was proposed where it was proposed that in-situ grafts were formingon the clay surfaces during blending and the grafts then had to belocalized at the interfaces. This blending mechanism reflects thecomposition of the blend and is fairly nonspecific. As a result, this maybe a promising technology for use in processing recycled blends where thecomposition is often uncertain and price is of generalconcern.

  3. Study on combustion characteristics of blended coals

    Institute of Scientific and Technical Information of China (English)

    LI Yonghua; WANG Chunbo; CHEN Hongwei

    2007-01-01

    Power plants in China have to burn blended coal instead of one specific coal for a variety of reasons.So it is of great necessity to investigate the combustion of blended coals.Using a test rig with a capacity of 640 MJ/h with an absolute milling system and flue gas online analysis system,characteristics such as burnout,slag,and pollution of some blended coals were investigated.The ratio of coke and slag as a method of distinguishing coal slagging characteristic was introduced.The results show that the blending of coal has some effect on NOx but there is no obvious rule.SOx emission can be reduced by blending low sulfur coal.

  4. THE EFFECT OF BLENDING SEQUENCE ON PHASE MORPHOLOGY OF NYLON 6/ABS/SMA BLENDS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The preparation process-dependent phase morphology of blends composed of nylon 6 and acryionitrile-butadienestyrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of nylon 6 when ABS was blended with the preblended nylon 6/SMA blend,while the co-continuous structures could be observed over a considerably narrower composition range when nylon 6 was blended with the pre-blended ABS/SMA blend.An examination through dynamic mechanical analysis (DMA)tests confirmed the results obtained with SEM.It is found that near the phase inversion region a remarkable change in the dynamic storage modulus(G')and the loss tangent(tanδ)appears.Moreover,the influence of blending sequence on the size of dispersed particles has been probed for uncompatibilized and compatibilized blends of nylon 6 and ABS over a wide range of compositions below or beyond the phase inversion points.For the blends of ABS dispersed in a nylon 6 matrix,little discernible effects of blending sequence on particle size could be observed.Furthermore,there exists a significant difference in morphologies of the blends prepared by nylon 6 particles dispersing in a ABS matrix in cases of different blending sequences used.Some possible factors responsible for the above asymmetric behaviors have been proposed.

  5. Blending traditional and digital marketing

    Directory of Open Access Journals (Sweden)

    Raluca Dania TODOR

    2016-07-01

    Full Text Available It is a matter of fact that we are in the digital era and internet marketing and social media have a significant impact on the way consumers behave, companies do business and it is a must for companies to adapt to the new reality. Due to the fast evolution of the technology, the continuous increase in demand and supply, the supply chain elongation and the big amount of date, the only solution to face the major changes is the automation of all the processes. But even though the new era of communication is here, specialist suggest that companies should not ignore traditional methods, and to try to blend digital marketing with traditional campaigns in order to achieve their goals.

  6. Relations between blended learning possibilities and teachers' approaches to blended learning

    DEFF Research Database (Denmark)

    Stenalt, Maria Hvid; Nielsen, Tobias Alsted; Bager-Elsborg, Anna

    suggest that in order to identify the level of impact of integrating technologies in teaching and learning, we need to understand the factors influencing approaches to design of courses for blended contexts. Participants in the teacher training project come from the Department of Law at Aarhus University......Higher Education has embraced blended learning as a way of enhancing quality in teaching and helping students to learn. This presentation addresses relations between blended learning possiblities presented to teachers in a teacher training project and teachers’ approaches to blended learning. We......: • Optain locally-embedded knowledge about blended learning • Develop opportunities for law students to receive (more) feedback • Comply with strategic aims The results so far suggest that teachers provide a disciplinary perspective on the key dimensions of blended learning, which influences...

  7. Morphology Evolution of Polycarbonate-Polystyrene Blends During Compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib;

    2001-01-01

    The morphology evolution of polycarbonate-polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, re-melt blending in a twin-screw extruder and tri-melt blending in an injection-moulding machine, was investigated using......-empirical model. The results show that the formation of co-continuous morphology strongly depends on blend composition and melt blending method, whereas the model prediction for phase inversion deviates from the experimental values. Further, we found that the initial mechanism of morphology evolution involves...

  8. Thin films of photoactive polymer blends.

    Science.gov (United States)

    Ruderer, Matthias A; Metwalli, Ezzeldin; Wang, Weinan; Kaune, Gunar; Roth, Stephan V; Müller-Buschbaum, Peter

    2009-03-09

    The morphology inside photoactive blended films of two conjugated homopolymers poly [(1-methoxy)-4-(2-ethylhexyloxy)-p-phenylene-vinylene] (MEH-PPV) and poly(3-hexylthiophene-2,5-diyl) (P3HT) is investigated. For both homopolymers a linear dependence of the installed film thickness from the concentration of the polymer solution used in spin coating is probed. This dependence allows preparation of an efficient series of blended films with constant thickness and different blending ratios. Information about the lateral structure inside the films is gained from grazing incidence small angle X-ray scattering. At the calculated critical blending ratio the smallest lateral separation between adjacent domains is found representing the highest surface contact between both homopolymers in the films. The presence of wetting layers at both interfaces as detected with X-ray reflectivity and atomic force microscopy is promising for photovoltaic applications. UV/Vis spectroscopy complements the structural investigation.

  9. Blending Parametric Patches with Subdivision Surfaces

    Institute of Scientific and Technical Information of China (English)

    李桂清; 李华

    2002-01-01

    In this paper the problem of blending parametric surfaces using subdivision patches is discussed. A new approach, named removing-boundary, is presented to generate piecewise-smooth subdivision surfaces through discarding the outmost quadrilaterals of the open meshes derived by each subdivision step. Then the approach is employed both to blend parametric bicubic B-spline surfaces and to fill n-sided holes. It is easy to produce piecewisesmooth subdivision surfaces with both convex and concave corners on the boundary, and limit surfaces are guaranteed to be C2 continuous on the boundaries except for a few singular points by the removing-boundary approach. Thus the blending method is very efficient and the blending surface generated is of good effect.

  10. NESDIS Blended Total Precipitable Water (TPW) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Total Precipitable Water (TPW) product is derived from multiple sensors/satellites. The Percentage of TPW normal (PCT), or TPW anomaly, shows the...

  11. Sausage Blending Using Multiple Objective Linear Programming

    OpenAIRE

    Steuer, Ralph E.

    1984-01-01

    Single objective cost minimization linear programming models are used as computerized decision-aids in sausage manufacturing (hot dogs, bologna, salami, etc.). However, sausage blending is clearly a problem with multiple conflicting criteria (cost, color, fat, protein, moisture, etc.) Presented in this paper is a vector-maximum/filtering MOLP (multiple objective linear programming) methodology for use as an improved decision-making approach with single formula sausage blending problems.

  12. Blended Interaction Spaces for Collaborative Design

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Halskov, Kim; Klokmose, Clemens Nylandsted

    During the past five years, we have explored the use, potentials and challenges of Blended Interaction spaces. In addition, we have a long background in developing and exploring methods for collaborative design. In this workshop paper, we give an overview of our work and present our visions...... and ongoing research in developing Blended Interaction spaces for collaborative design. We then identify key themes and challenges pertinent for the workshop....

  13. WI Biodiesel Blending Progream Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Redmond, Maria E; Levy, Megan M

    2013-04-01

    The Wisconsin State Energy Office's (SEO) primary mission is to implement cost effective, reliable, balanced, and environmentally friendly clean energy projects. To support this mission the Wisconsin Biodiesel Blending Program was created to financially support the installation infrastructure necessary to directly sustain biodiesel blending and distribution at petroleum terminal facilities throughout Wisconsin. The SEO secured a federal directed award of $600,000 over 2.25 years. With these funds, the SEO supported the construction of inline biodiesel blending facilities at two petroleum terminals in Wisconsin. The Federal funding provided through the state provided a little less than half of the necessary investment to construct the terminals, with the balance put forth by the partners. Wisconsin is now home to two new biodiesel blending terminals. Fusion Renewables on Jones Island (in the City of Milwaukee) will offer a B100 blend to both bulk and retail customers. CITGO is currently providing a B5 blend to all customers at their Granville, WI terminal north of the City of Milwaukee.

  14. Network reconstruction via graph blending

    Science.gov (United States)

    Estrada, Rolando

    2016-05-01

    Graphs estimated from empirical data are often noisy and incomplete due to the difficulty of faithfully observing all the components (nodes and edges) of the true graph. This problem is particularly acute for large networks where the number of components may far exceed available surveillance capabilities. Errors in the observed graph can render subsequent analyses invalid, so it is vital to develop robust methods that can minimize these observational errors. Errors in the observed graph may include missing and spurious components, as well fused (multiple nodes are merged into one) and split (a single node is misinterpreted as many) nodes. Traditional graph reconstruction methods are only able to identify missing or spurious components (primarily edges, and to a lesser degree nodes), so we developed a novel graph blending framework that allows us to cast the full estimation problem as a simple edge addition/deletion problem. Armed with this framework, we systematically investigate the viability of various topological graph features, such as the degree distribution or the clustering coefficients, and existing graph reconstruction methods for tackling the full estimation problem. Our experimental results suggest that incorporating any topological feature as a source of information actually hinders reconstruction accuracy. We provide a theoretical analysis of this phenomenon and suggest several avenues for improving this estimation problem.

  15. Blended Learning: How Teachers Balance the Blend of Online and Classroom Components

    Science.gov (United States)

    Jeffrey, Lynn M.; Milne, John; Suddaby, Gordon

    2014-01-01

    Despite teacher resistance to the use of technology in education, blended learning has increased rapidly, driven by evidence of its advantages over either online or classroom teaching alone. However, blended learning courses still fail to maximize the benefits this format offers. Much research has been conducted on various aspects of this problem,…

  16. Mercury reduction by coal blending : effects of boiler configuration and blending on mercury speciation

    Energy Technology Data Exchange (ETDEWEB)

    Lyng, R. [Ontario Power Generation Nanticoke Generating Station, Nanticoke, ON (Canada)

    2006-07-01

    Ontario Power Generation has explored the potential of reducing mercury emissions through fuel blending on full-scale operating units at its 8 x 500 MW Nanticoke coal-fired generating station. This presentation addressed the issue of unit configuration on mercury speciation. It outlined full scale testing of mercury emissions in 2004 and the potential for mercury control suggested by the test data. Mercury emissions were measured for the firing of various eastern US bituminous and western US sub-bituminous Powder River Basin (PRB) coal blends. Three blends of up to 84 per cent sub-bituminous coal were tested. Two methods of coal blending, selective bunkering and silo or field blending were also tested. Mercury emissions under boiler configurations with and without selective catalytic reduction (SCR) and over-fire air were compared. This paper included the results from semi-continuous monitoring (SCM) data collected during the test period. A high mercury oxidation was observed over chlorine concentration ranges of 0.3 to 0.1 per cent. It was noted that feeding dedicated fuels to mills, rather than yard blends of bituminous PRB, results in higher levels of mercury capture, particularly at higher than 16:84 blend. A consistently high level of oxidation was noted across the SCR demonstrated for all blends tested. It was noted that Over Fire Air (OFA) advanced combustion technology systems appeared to increase mercury oxidation. tabs., figs.

  17. Blended Training for Combat Medics

    Science.gov (United States)

    Fowlkes, Jennifer; Dickinson, Sandra; Lazarus, Todd

    2010-01-01

    Bleeding from extremity wounds is the number one cause of preventable death on the battlefield and current research stresses the importance of training in preparing every Soldier to use tourniquets. HapMed is designed to provide tourniquet application training to combat medics and Soldiers using a blended training solution encompassing information, demonstration, practice, and feedback. The system combines an instrumented manikin arm, PDA, and computer. The manikin arm provides several training options including stand-alone, hands-on skills training in which soldiers can experience the actual torque required to staunch bleeding from an extremity wound and be timed on tourniquet application. This is more realistic than using a block of wood to act as a limb, which is often how training is conducted today. Combining the manikin arm with the PDA allows instructors to provide scenario based training. In a classroom or field setting, an instructor can specify wound variables such as location, casualty size, and whether the wound is a tough bleed. The PDA also allows more detailed feedback to be provided. Finally, combining the manikin arm with game-based technologies, the third component, provides opportunities to build knowledge and to practice battlefield decision making. Not only do soldiers learn how to apply a tourniquet, but when to apply a tourniquet in combat. The purpose of the paper is to describe the learning science underlying the design of HapMed, illustrate the training system and ways it is being expanded to encompass other critical life-saving tasks, and report on feedback received from instructors and trainees at military training and simulation centers.

  18. Moisture sorption and thermal characteristics of polyaramide blend fabrics

    OpenAIRE

    Genç, Gözde; Alp, Burcu; Balköse, Devrim; Ülkü, Semra; Cireli, Aysun

    2006-01-01

    Four types of fabrics woven from various polyaramid fibers of Nomex and Kevlar blends were characterized by morphology, XRD, elemental analysis, thermal analysis, and moisture adsorption isotherms. The blends consisted of Polybenzimidazole/ Kevlar blend (40% FBI and 60% Kevlar®), Nomex Delta A (blend of 60% Kevlar and 40% Nomex®), Nomex Delta T (blend of 75% Nomex, 23% Kevlar, and 2% P140 antistatic fiber), and Nomex III (fabric with a 95/5 blend of Nomex and Kevlar) containing 1% steel fiber...

  19. HIGH SCHOOL STUDENTS’ VIEWS ON BLENDED LEARNING

    Directory of Open Access Journals (Sweden)

    Ibrahim Umit YAPICI,

    2012-08-01

    Full Text Available In this study, it is aimed to determine the high school students’ views on blended learning. The study was carried out in biology course for the lesson unit of “Classification of Living Things and Biodiversity” with 47 9th grade students attending Nevzat Ayaz Anatolian High School in the second term of the academic year of 2009-2010. The lessons were taught in a way appropriate to the blended learning model both via the Internet and on face-to-face basis. As the online dimension of the blended learning model, Moodle, a Learning Management System (LMS, was used. The application lasted 10 weeks. The scale of learners’ views on blended learning was applied and interviews were held to determine the views. As a result of the analysis of the scale, it was seen that their views were “highly” positive. The interviews held with the students revealed that the blended learning model provided students with various opportunities such as getting prepared for the lessons, reviewing the lessons as many times as wanted, reaching the subject-related materials without being dependent on time and place, testing oneself and communicating with the teacher and other students out of the school. The interviews also revealed that there were various problems though such as lack of Internet connection at home and problems experienced while playing the videos.

  20. Blended coals for improved coal water slurries

    Institute of Scientific and Technical Information of China (English)

    GU Tian-ye; WU Guo-guang; LI Qi-hui; SUN Zhi-qiang; ZENG Fang; WANG Guang-you; MENG Xian-liang

    2008-01-01

    Three coal samples of different ranks were used to study the effect of coal blending on the preparation of Coal Water Slurry (CWS). The results show that by taking advantage of two kinds of coal, the coal concentration in slurry made from hard-to-pulp coal can be effectively improved and increased by 3%-5% generally. DLT coal (DaLiuTa coal mine) is very poor in slurryability and the stability and rheology of the resulting slurry are not very good. When the amount of easily slurried coal is more than 30%, all properties of the CWS improve and the CWS meets the requirements for use as fuel. Coalification, porosity, surface oxygenic functional groups, zeta potential and grindability have a great effect on the performance of blended coal CWS. This leads to some differences in performance between the slurry made from a single coal and slurry made from blended coal.

  1. REVERSE MODELING FOR CONIC BLENDING FEATURE

    Institute of Scientific and Technical Information of China (English)

    Fan Shuqian; Ke Yinglin

    2005-01-01

    A novel method to extract conic blending feature in reverse engineering is presented.Different from the methods to recover constant and variable radius blends from unorganized points, it contains not only novel segmentation and feature recognition techniques, but also bias corrected technique to capture more reliable distribution of feature parameters along the spine curve. The segmentation depending on point classification separates the points in the conic blend region from the input point cloud. The available feature parameters of the cross-sectional curves are extracted with the processes of slicing point clouds with planes, conic curve fitting, and parameters estimation and compensation. The extracted parameters and its distribution laws are refined according to statistic theory such as regression analysis and hypothesis test. The proposed method can accurately capture the original design intentions and conveniently guide the reverse modeling process. Application examples are presented to verify the high precision and stability of the proposed method.

  2. Phase Segregation in Polystyrene?Polylactide Blends

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Bonnie; Hitchcock, Adam; Brash, John; Scholl, Andreas; Doran, Andrew

    2010-06-09

    Spun-cast films of polystyrene (PS) blended with polylactide (PLA) were visualized and characterized using atomic force microscopy (AFM) and synchrotron-based X-ray photoemission electron microscopy (X-PEEM). The composition of the two polymers in these systems was determined by quantitative chemical analysis of near-edge X-ray absorption signals recorded with X-PEEM. The surface morphology depends on the ratio of the two components, the total polymer concentration, and the temperature of vacuum annealing. For most of the blends examined, PS is the continuous phase with PLA existing in discrete domains or segregated to the air?polymer interface. Phase segregation was improved with further annealing. A phase inversion occurred when films of a 40:60 PS:PLA blend (0.7 wt percent loading) were annealed above the glass transition temperature (Tg) of PLA.

  3. Preliminary assessment of blending Hanford tank wastes

    Energy Technology Data Exchange (ETDEWEB)

    Geeting, J.G.H.; Kurath, D.E.

    1993-03-01

    A parametric study of blending Hanford tank wastes identified possible benefits from blending wastes prior to immobilization as a high level or low level waste form. Track Radioactive Components data were used as the basis for the single-shell tank (SST) waste composition, while analytical data were used for the double-shell tank (DST) composition. Limiting components were determined using the existing feed criteria for the Hanford Waste Vitrification Plant (HWVP) and the Grout Treatment Facility (GTF). Results have shown that blending can significantly increase waste loading and that the baseline quantities of immobilized waste projected for the sludge-wash pretreatment case may have been drastically underestimated, because critical components were not considered. Alternatively, the results suggest further review of the grout feed specifications and the solubility of minor components in HWVP borosilicate glass. Future immobilized waste estimates might be decreased substantially upon a thorough review of the appropriate feed specifications.

  4. COMPOSITION CHANGES IN REFRIGERANT BLENDS FOR AUTOMOTIVE AIR CONDITIONING

    Science.gov (United States)

    Three refrigerant blends used to replace CFC-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in b...

  5. Model for blended learning i de tekniske uddannelser

    DEFF Research Database (Denmark)

    Ringtved, Ulla Lunde; Leth, Lilli-Ann Thomsen; Olsen, Frank;

    2012-01-01

    Anvendelse af blended learning i de tekniske uddannelser i UCN med udgangspunkt i bygningskonstruktøruddannelsen......Anvendelse af blended learning i de tekniske uddannelser i UCN med udgangspunkt i bygningskonstruktøruddannelsen...

  6. Reactive modification of polyesters and their blends

    Science.gov (United States)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

  7. Composites and blends from biobased materials

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, S.S. [National Renewable Energy Laboratory, Golden, CO (United States)

    1995-05-01

    The program is focused on the development of composites and blends from biobased materials to use as membranes, high value plastics, and lightweight composites. Biobased materials include: cellulose derivative microporous materials, cellulose derivative copolymers, and cellulose derivative blends. This year`s research focused on developing an improved understanding of the molecular features that cellulose based materials with improved properties for gas separation applications. Novel cellulose ester membrane composites have been developed and are being evaluated under a collaborative research agreement with Dow Chemicals Company.

  8. Blended Course with Flipped Classroom Approach

    DEFF Research Database (Denmark)

    Timcenko, Olga; Purwins, Hendrik; Triantafyllou, Evangelia;

    2015-01-01

    This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions will be descr......This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions...

  9. COMPUTATION OF VECTOR VALUED BLENDING RATIONAL INTERPOLANTS

    Institute of Scientific and Technical Information of China (English)

    檀结庆

    2003-01-01

    As we know, Newton's interpolation polynomial is based on divided differ-ences which can be calculated recursively by the divided-difference scheme while Thiele'sinterpolating continued fractions are geared towards determining a rational functionwhich can also be calculated recursively by so-called inverse differences. In this paper,both Newton's interpolation polynomial and Thiele's interpolating continued fractionsare incorporated to yield a kind of bivariate vector valued blending rational interpolantsby means of the Samelson inverse. Blending differences are introduced to calculate theblending rational interpolants recursively, algorithm and matrix-valued case are dis-cussed and a numerical example is given to illustrate the efficiency of the algorithm.

  10. Effect of Blending Ratio on the Properties of Ramie/Polyester Blended Yarn

    Institute of Scientific and Technical Information of China (English)

    YU Wen

    2002-01-01

    The effects of the blending ratio on the properties of Ramie/Polyester blended yarns are discussed in this paper. The experimental results show that the elongation of the yarn with the polyester content more than 40% is better than that of others. There is a lowest tenacity of the yarn corresponding to the blending ratio of 50/50 or so. The other properties of the yarn, such as the evenness and hairiness, will be improved with the increasing of the polyester content.

  11. Structure and Property of Silk Fibroin / Cellulose Blend Film

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-qiang; XING Tie-ling

    2004-01-01

    Silk fibroin/cellulose blend films were prepared using N-methylmorpholine -N-oxide (NMMO) as solvent. The effects of different proportions and solid contents on properties of blend films were discussed. The mechanical properties showed that the blend films had preferable moisture permeability and a high strength. The structures of the blend films were investigated by infrared spectrum and X-ray diffraction. The results indicated the occurrence of hydrogen bonds between hydroxyl groups of cellulose and amido groups of fibroin.

  12. THERMAL BEHAVIOR OF THERMOTROPIC HYDROXYETHYL CELLULOSE ACETATE/POLYETHYLENE BLENDS

    Institute of Scientific and Technical Information of China (English)

    WANG Hailin; CHEN Jinming; HUANG Yong; SHEN Jiarui

    1997-01-01

    The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is affected by HECA chains in the blends with more than 50% HECA, which results in the subordinate crystallization of PE and the formation of imperfect structures in the PE crystals. The imperfection of PE crystals in the blends can be eliminated after annealing at 393K.

  13. THE RADIATION CROSSLINKING OF EPR/SBR BLEND

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wanxi; L(U) Yingtao; SUN Jiazhen

    1990-01-01

    The radiation crosslinking of EPR/SBR blend has been studied. A relationship between sol fraction and radiation dose for the different weight ratio polymer blends and the method to calculate βb value of EPR/SBR blend system have been established.

  14. Benefits of blended acquisition with dispersed source arrays (DSA)

    NARCIS (Netherlands)

    Caporal, M.; Blacquiere, G.

    2015-01-01

    In blended data acquisition, the recorded wave field is incoherent. Nevertheless blended source units in the arrays are historically chosen to be equal. We propose to abandon this constraint. This allows us to suggest the exploitation of inhomogeneous blended sources, together representing a Dispers

  15. Blended Learning within an Undergraduate Exercise Physiology Laboratory

    Science.gov (United States)

    Elmer, Steven J.; Carter, Kathryn R.; Armga, Austin J.; Carter, Jason R.

    2016-01-01

    In physiological education, blended course formats (integration of face-to-face and online instruction) can facilitate increased student learning, performance, and satisfaction in classroom settings. There is limited evidence on the effectiveness of using blending course formats in laboratory settings. We evaluated the impact of blended learning…

  16. "Comfort" as a Critical Success Factor in Blended Learning Courses

    Science.gov (United States)

    Futch, Linda S.; deNoyelles, Aimee; Thompson, Kelvin; Howard, Wendy

    2016-01-01

    There are substantial quantitative research and anecdotal reports on blended learning and blended learning courses. However, few research studies focus on what happens at the classroom level. This research study aims to consider the highly contextual environment of effective blended learning courses by identifying the strategies instructors use to…

  17. Transitioning to Blended Learning: Understanding Student and Faculty Perceptions

    Science.gov (United States)

    Napier, Nannette P.; Dekhane, Sonal; Smith, Stella

    2011-01-01

    This paper describes the conversion of an introductory computing course to the blended learning model at a small, public liberal arts college. Blended learning significantly reduces face-to-face instruction by incorporating rich, online learning experiences. To assess the impact of blended learning on students, survey data was collected at the…

  18. Miscibility evolution of polycarbonate/polystyrene blends during compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib

    2002-01-01

    polymer in the other. The observed solubility strongly depends on blend composition and blending method. The T-g measurements showed maximum mutual solubility around 50/50 composition. The miscibility of PC/PS blended after the third stage (melt injection molding) was higher than that after the first...... stages (melt extrusion) and the second stages (remelt extrusion)....

  19. EFFECT of blend ratio and compatibilizer on solution casted treated waste natural rubber latex/polystyrene blends

    OpenAIRE

    Orathai Boondamnoen; A. Rashid Azura; Masahiro Ohshima; Saowaroj Chuayjuljit; Azlan Ariffin

    2013-01-01

    Natural rubber latex waste (WL) was treated with natural rubber latex (NRL) prior to blend with polystyrene. Differentblend compositions of treated waste natural rubber latex (TWL) and PS were carried out through solution blending. Tensileand tear properties were investigated. The compatibility improvement of the 70/30 TWL/PS blends was further investigatedusing styrene butadiene rubber (SBR) and styrene graft natural rubber (SNR) as compatibilizer. The mechanical properties forTWL/PS blends ...

  20. Systematic Methodology for Design of Tailor-Made Blended Products: Fuels and Other Blended Products

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza Binti

    important in daily life, since they not only keep people moving around, but also guarantee that machines and equipment work smoothly. The objective of this work is to tackle the blending problems using computer-aided tools for the initial stage of the product design. A systematic methodology for design......A tailor-made blended liquid product is defined as a formulation of various chemicals in the liquid state to obtain a liquid mixture with a specific set of desired characteristics and qualities. Examples of blended liquid products are synthetic fuels and lubricants. This type of products is very...... of tailor-made blended products has been developed, which has four main tasks. First, the design problem is defined: the product needs are identified, translated into target properties and the bounds for each target property are defined. Secondly, target property models are retrieved from a property model...

  1. High School Students' Views on Blended Learning

    Science.gov (United States)

    Yapici, Ibrahim Umit; Akbayin, Hasan

    2012-01-01

    In this study, it is aimed to determine the high school students' views on blended learning. The study was carried out in biology course for the lesson unit of "Classification of Living Things and Biodiversity" with 47 9[superscript th] grade students attending Nevzat Ayaz Anatolian High School in the second term of the academic year of 2009-2010.…

  2. Multiple Perspectives on Blended Learning Design

    Science.gov (United States)

    Collis, Betty; Margaryan, Anoush; Amory, Marc

    2005-01-01

    Learning in the corporate setting not only relates to individual competence development but also to a demonstration of business impact and a contribution to the strategic ambitions of the company. An approach to learning design that blends generic principles of learning and instruction with strategic goals important to the particular context,…

  3. Porous Polyolefin Films via Polymer Blends

    Science.gov (United States)

    Macosko, Chris

    Porous polymer films have broad application including battery separators, membrane supports and filters. Polyolefins are attractive for these applications because of their solvent resistance, low electrical and thermal conductivity, easy fabrication and cost. We will describe fabrication of porous films using cocontinuous blends of a polyolefin with another polymer which can be readily removed with a solvent. Methods to image and control the cocontinuous morphology will be presented.Bell, J. R., K. Chang, C. R. Lopez-Barron, C. W. Macosko, and D. C. Morse, ''Annealing of cocontinuous polymer blends: effect of block copolymer molecular weight and architecture,'' Macromolecules 43, 5024-5032 (2010).Lopez-Barron, C. R., and C. W. Macosko, ''Direct measurement of interface anisotropy of bicontinuous structures via 3D image analysis,'' Langmuir 26, 14284-14293 (2010).Trifkovic, M., A. T. Hedegaard, K. Huston, M. Sheikhzadeh, and C. W. Macosko, ''Porous films via PE/PEO cocontinuous blends,'' Macromolecules 45, 6036-6044 (2012).Hedegaard, A.T., L.L. Gu and C. W. Macosko, ``Effect of Extensional Viscosity on Cocontinuity of Immiscible Polymer Blends'' J. Rheol. 59, 1397-1417 (2015).

  4. Blended learning tools for teaching and training

    CERN Document Server

    Allan, Barbara

    2007-01-01

    Offers a holistic blended learning approach, combining the best of traditional approaches to learning and teaching to make best use of the advantages of each while minimizing the disadvantages. It provides information professionals with a practical guide to the design and delivery of such training programmes.

  5. The Ellipticity Distribution of Ambiguously Blended Objects

    CERN Document Server

    Dawson, William A; Tyson, J Anthony; Jee, M James

    2014-01-01

    Using overlapping fields with space-based Hubble Space Telescope (HST) and ground-based Subaru Telescope imaging we identify a population of blended galaxies that would not be easily distinguished with ground-based monochromatic imaging alone, which we label as 'ambiguous blends'. For the depth targeted with the Large Synoptic Survey Telescope (LSST), the ambiguous blend population is both large (~14%) and has a distribution of ellipticities that is markedly different from that of unblended objects in a way that will likely be important for the weak lensing measurements. Most notably, we find that ambiguous blending results in a ~14% increase in shear noise (or ~12% decrease in the effective number density of galaxies, $n_{eft}$) due to 1) larger intrinsic ellipticity dispersion, 2) a scaling with the galaxy number density $N_{gal}$ that is shallower than 1/$\\sqrt{N_{gal}}$. For the LSST Gold Sample (i<25.3) there is a $\\sim$7\\% increase in shear noise (or ~7% decrease in $n_{eff}$)

  6. Miscibility of polymer blends with engineering models

    DEFF Research Database (Denmark)

    Vassilis, Harismiadis; van Bergen, A. R. D.; Goncalves, Ana Saraiva;

    1996-01-01

    The miscibility behavior of polymer blends that do not exhibit strong specific interactions is examined. Phase equilibrium calculations are presented with the van der Waals equation of state and three group-contribution models (UNIFAC, Entropic-FV, and GC-Flory). Performance of these models is al...

  7. Nitrate Salt Surrogate Blending Scoping Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Anast, Kurt Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-13

    Test blending equipment identified in the “Engineering Options Assessment Report: Nitrate Salt Waste Stream Processing”. Determine if the equipment will provide adequate mixing of zeolite and surrogate salt/Swheat stream; optimize equipment type and operational sequencing; impact of baffles and inserts on mixing performance; and means of validating mixing performance

  8. Improving Curriculum through Blended Learning Pedagogy

    Directory of Open Access Journals (Sweden)

    Ojat DAROJAT

    2016-10-01

    Full Text Available This paper is a study of blended learning pedagogy in open and distance learning (ODL, involving two universities in Southeast Asia, STOU Thailand and UT Indonesia. The purpose of this study is to understand the issues related to the implementation of blended-learning pedagogy. Existing theories in Distance education (DE specifically interaction and communication theory proposed by Holmberg (1995, autonomy and independence theory based on the work Wedemeyer (1981 and Moore (1994 and community of inquiry (CoI model contributed by Garrison, Anderson, and Archer (2000 are detected to provide a general picture on how practices in teaching-learning provisions and DE theories may inform each other. Qualitative case study was employed to optimize my understanding of the blended learning phenomena gathered through semi-structured interview and documentary analysis. Whilst they operated in different educational settings, these two universities shared similarities. They have developed blended learning pedagogy to promote students’ learning classified into three dimensions: printed learning materials, F2F sessions, and online learning. Printed materials, however, may be identified as a major one and online learning have been regarded as strategic policies for further development. They have been equipped with their VLE; the use of VLE helped these universities to provide two-way traffic communications. They have been involved in developing internet-based instruction to widening access and to meet challenges for better future.

  9. Blending zone determination for aerial orthimage mosaicking

    Science.gov (United States)

    Lin, Chao-Hung; Chen, Bo-Heng; Lin, Bo-Yi; Chou, Han-Szu

    2016-09-01

    Creating a composed image from a set of aerial images is a fundamental step in orthomosaic generation. One of the processes involved in this technique is determining an optimal seamline in an overlapping region to stitch image patches seamlessly. Most previous studies have solved this optimization problem by searching for a one-pixel-wide seamline with an objective function. This strategy significantly reduced pixel mismatches on the seamline caused by geometric distortions of images but did not fully consider color discontinuity and mismatch problems that occur around the seamline, which sometimes cause mosaicking artifacts. This study proposes a blending zone determination scheme with a novel path finding algorithm to reduce the occurrence of unwanted artifacts. Instead of searching for a one-pixel-wide seamline, a blending zone, which is a k-pixel-wide seamline that passes through high-similarity pixels in the overlapping region, is determined using a hierarchical structure. This strategy allows for not only seamless stitching but also smooth color blending of neighboring image patches. Moreover, the proposed method searches for a blending zone without the pre-process of highly mismatched pixel removal and additional geographic data of road vectors and digital surface/elevation models, which increases the usability of the approach. Qualitative and quantitative analyses of aerial images demonstrate the superiority of the proposed method to related methods in terms of avoidance of passing highly mismatched pixels.

  10. Blended learning pedagogy: the time is now!

    Science.gov (United States)

    Pizzi, Michael A

    2014-07-01

    Pedagogy is rapidly changing. To develop best practice in academia, it is important that we change with the changing needs of students. This article suggests that blended learning is one of the most important pedagogical formats that can enhance student learning, optimize the use of active learning strategies, and potentially improve student learning outcomes.

  11. Messy Design: Organic Planning for Blended Learning

    Science.gov (United States)

    Rankin, Andrea; Luzeckyj, Ann; Haggis, Jane; Gare, Callum

    2016-01-01

    In this paper we argue that a messy design process does not mitigate against sharing and transfer of artefacts across educational domains. In fact, such a process can aid in developing a model for learning and teaching that is reusable and authentic. We describe the planning and design of an integrated and interactive blended learning environment…

  12. The Effectiveness of Blended Learning Environments

    Science.gov (United States)

    Eryilmaz, Meltem

    2015-01-01

    The object of this experimental study is to measure the effectiveness of a blended learning environment which is laid out on the basis of features for face to face and online environments. The study was applied to 110 students who attend to Atilim University, Ankara, Turkey and take Introduction to Computers Course. During the application,…

  13. CEDS Addresses: Virtual and Blended Learning

    Science.gov (United States)

    US Department of Education, 2015

    2015-01-01

    The Common Education Data Standards (CEDS) common data vocabulary supports the collection and use of information about virtual and blended learning. The data element "Virtual Indicator", introduced in version 3 of CEDS, supports a range of virtual learning-related use cases. The Virtual Indicator element may be related to a Course…

  14. A Multimodal Interaction Framework for Blended Learning

    DEFF Research Database (Denmark)

    Vidakis, Nikolaos; Kalafatis, Konstantinos; Triantafyllidis, Georgios

    2017-01-01

    Humans interact with each other by utilizing the five basic senses as input modalities, whereas sounds, gestures, facial expressions etc. are utilized as output modalities. Multimodal interaction is also used between humans and their surrounding environment, although enhanced with further senses ...... framework enabling deployment of a vast variety of modalities, tailored appropriately for use in blended learning environment....

  15. Chitosan films and blends for packaging material

    NARCIS (Netherlands)

    Broek, van den L.A.M.; Knoop, J.R.I.; Kappen, F.H.J.; Boeriu, C.G.

    2015-01-01

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory an

  16. Use of blended learning in workplace learning

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Løvstad, Charlotte Vange

    2014-01-01

    -based teaching materials. This paper presents the experiences of this particular project, and goes on to discuss the following points: • The blended learning design – use of IT for teaching, learning and communication • Digital learning materials – principals of design and use • Work place learning and learning...

  17. Compatibilizing Bulk Polymer Blends by Using Organoclays

    Science.gov (United States)

    Si, Mayu; Gersappe, Dilip; Zhang, Wenhua; Ade, Harald; Rafailovich, Miriam; Sokolov, Jonathan; Rudomen, Gregory; Schwartz, Bradley; Fisher, Robert

    2004-03-01

    We investigated the compatiblizing performance of organoclays on melt mixed binary and tertiary polymer blends, such as, PS/PMMA, PC/SAN, PS/PMMA/PVC and PS/PMMA/PE. These polymer blends were characterized by TEM, STXM, DSC and DMA. TEM and STXM photographs show that the addition of organoclays into polymer blends drastically reduces the average domain size of the component phases. And the organoclay goes to the interfacial region between the different polymers and effectively slows down the domain size increasing during high temperature annealing. DMA and DSC results show the effect of organoclays on the mechanical properties and glass transitions temperature, which indicates the compatibilization on the molecular level. The generalized compatibilization induced by the nanoscale fillers for blends can be explained in terms of mean field models where the reduction of interfacial tension induced by in-situ grafting is counterbalanced by the increased bending energy due to the rigidity of the filler. This in turn can be shown to be a function of the degree of exfoliation, aspect ratio, and polymer filler interactions. Supported by NSF funded MRSEC at Stony Brook

  18. Blends of ascarosides regulate dispersal in nematodes

    Science.gov (United States)

    Blends of ascarosides regulate dispersal in nematodes Presenter: Dr. Fatma Kaplan Dispersal is an important behavior for many organisms. It can easily be observed when infectious juveniles of entomopathogenic nematodes (Steinernema and Heterorhabditis) leave a consumed insect host. Dauer larvae of ...

  19. Effect of blended learning to academic achievement

    Directory of Open Access Journals (Sweden)

    Veysel Karani Ceylan

    2017-02-01

    Full Text Available In this study, the effects of blended learning on the middle school students’ academic achievement level and product evaluation scores were investigated. Blended learning provides more effective learning outcome gains through enriching todays’ developing Web Technologies with learning environments. This study was carried out with a total of 53 students enrolled in the experimental group and control group in the 6th grade classrooms during the 2014/2015 school year in a middle school in southwest part of Turkey. The intervention lasted 7 weeks. During the seven weeks, the unit of “problem solving, computer programming and development of Software product”, covered in Educational technologies and Software course, is taught through blended learning environment. The experimental group was taught using blended learning environment which supported with enriched web technologies (such as video-conference, Learning Management System, Discussion blogs , etc.. Whereas the experimental group was given access to all these enriched contents that are presented to the control group only during the classroom environment through present teaching methods. The design of the study includes quantitative method. We collected quantitative data such as academic achievement test and product evaluation scale. Academic achievement test and product evaluation scale were used as quantitative data collection sources. Quantitative data was collected through the evaluation of students’ projects that they developed during the process of the study and the academic achievement tests. During the data analysis phase, independent t-test, frequency and ANOVA tests were used. As a result of this study, it is concluded that blended learning environment had generated a significant difference in students’ academic achievement on behalf of experimental group. Implications of the study for the educational environments were discussed.

  20. Intermediate Ethanol Blends Catalyst Durability Program

    Energy Technology Data Exchange (ETDEWEB)

    West, Brian H; Sluder, Scott; Knoll, Keith; Orban, John; Feng, Jingyu

    2012-02-01

    In the summer of 2007, the U.S. Department of Energy (DOE) initiated a test program to evaluate the potential impacts of intermediate ethanol blends (also known as mid-level blends) on legacy vehicles and other engines. The purpose of the test program was to develop information important to assessing the viability of using intermediate blends as a contributor to meeting national goals for the use of renewable fuels. Through a wide range of experimental activities, DOE is evaluating the effects of E15 and E20 - gasoline blended with 15% and 20% ethanol - on tailpipe and evaporative emissions, catalyst and engine durability, vehicle driveability, engine operability, and vehicle and engine materials. This report provides the results of the catalyst durability study, a substantial part of the overall test program. Results from additional projects will be reported separately. The principal purpose of the catalyst durability study was to investigate the effects of adding up to 20% ethanol to gasoline on the durability of catalysts and other aspects of the emissions control systems of vehicles. Section 1 provides further information about the purpose and context of the study. Section 2 describes the experimental approach for the test program, including vehicle selection, aging and emissions test cycle, fuel selection, and data handling and analysis. Section 3 summarizes the effects of the ethanol blends on emissions and fuel economy of the test vehicles. Section 4 summarizes notable unscheduled maintenance and testing issues experienced during the program. The appendixes provide additional detail about the statistical models used in the analysis, detailed statistical analyses, and detailed vehicle specifications.

  1. Influence of blend microstructure on bulk heterojunction organic photovoltaic performance.

    Science.gov (United States)

    Brabec, Christoph J; Heeney, Martin; McCulloch, Iain; Nelson, Jenny

    2011-03-01

    The performance of organic photovoltaic devices based upon bulk heterojunction blends of donor and acceptor materials has been shown to be highly dependent on the thin film microstructure. In this tutorial review, we discuss the factors responsible for influencing blend microstructure and how these affect device performance. In particular we discuss how various molecular design approaches can affect the thin film morphology of both the donor and acceptor components, as well as their blend microstructure. We further examine the influence of polymer molecular weight and blend composition upon device performance, and discuss how a variety of processing techniques can be used to control the blend microstructure, leading to improvements in solar cell efficiencies.

  2. Study on mathematical model of steam coal blending

    Institute of Scientific and Technical Information of China (English)

    高洪阁; 李白英; 刘泽常; 尹增德

    2002-01-01

    It is necessary to set up a new mathematical model of steam coal blending instead of the old model. Indexes such as moisture content, ash content, volatile matter, sulfur content and heating value in the new mathematical model have linear relation. The new mathematical model can also predict ash-fusion temperature precisely by considering coal ash ratio in steam coal blending, therefore it is possible to obtain linear relation of ash-fusion temperature between single coal and steam coal blending. The new mathematical model can improve precision of steam coal blending and perfect the old mathematical model of steam coal blending.

  3. Silk fibroin/pullulan blend films: Preparation and characterization

    Science.gov (United States)

    Shivananda, C. S.; Rao, B. Lakshmeesha; Madhukumar, R.; Sarojini, B. K.; Somashekhar, R.; Asha, S.; Sangappa, Y.

    2016-05-01

    In this work silk fibroin/pullulan blend films have been prepared by solution casting method. The blend films were examined for structural, and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results indicate that with the introduction of pullulan, the interaction between SF and pullulan in the blend films induced the conformation transition of SF films and amorphous phase increases with increasing pullulan ratio. The thermal properties of the blend films were improved significantly in the blend films.

  4. Blended food for enteral feeding via a gastrostomy.

    Science.gov (United States)

    Brown, Suzanne

    2014-11-01

    A blended diet for enteral nutrition is defined as home-made everyday food blended to a smooth 'single cream' consistency. At present, blended food is not recommended as a first choice. However, the wishes of parents who prefer to use blended food for their child need to be respected, and hospice policy for Children's Hospice South West is to replicate home conditions as far as possible. Therefore guidelines have been created for use of a blended diet. However, benefits in physical and emotional health need to be balanced against risks of tube blockage, contamination and digestive upsets.

  5. Blended Learning-A Focus Study on Asia

    Directory of Open Access Journals (Sweden)

    Kwong Onn Tham

    2011-03-01

    Full Text Available Blended learning is gaining popularity in Asia. This paper examines the current stage of development of blended learning in higher education in China, Korea, Japan, and Singapore and the challenges encountered. While blended learning is well-received in western culture, it has met with varying degrees of success in Asia due in part to the different perceptions of instructors and students towards blended learning approaches. In China, for example, while blended learning was well-received, the dominance of traditional teaching methods goes against the conditions required for mainstream blended learning. A review of existing literature showed that there are a host of key issues and challenges which prevent Asian countries from harnessing the full potential of blended learning in higher education.

  6. Electrostatic contributions in the increased compatibility of polymer blends.

    Science.gov (United States)

    Linares, Elisângela M; Jannuzzi, Sergio A V; Galembeck, Fernando

    2011-12-20

    Successful blending of different polymers to make a structural or functional material requires overcoming limitations due to immiscibility and/or incompatibility that arise from large polymer-polymer interfacial tensions. In the case of latex blends, the combination of capillary adhesion during the blended dispersion drying stage with electrostatic adhesion in the final product is an effective strategy to avoid these limitations, which has been extended to a number of polymer blends and composites. This work shows that adhesion of polymer domains in blends made with natural rubber and synthetic latexes is enhanced by electrostatic adhesion that is in turn enhanced by ion migration, according to the results from scanning electric potential microscopy. The additional attractive force between domains improves blend stability and mechanical properties, broadening the possibilities and scope of latex blends, in consonance with the "green chemistry" paradigm. This novel approach based on electrostatic adhesion can be easily extended to multicomponent systems, including nonpolymers.

  7. Performance and emission characteristics of double biodiesel blends with diesel

    Directory of Open Access Journals (Sweden)

    Kuthalingam Arun Balasubramanian

    2013-01-01

    Full Text Available Recent research on biodiesel focused on performance of single biodiesel and its blends with diesel. The present work aims to investigate the possibilities of the application of mixtures of two biodiesel and its blends with diesel as a fuel for diesel engines. The combinations of Pongamia pinnata biodiesel, Mustard oil biodiesel along with diesel (PMD and combinations of Cotton seed biodiesel, Pongamia pinnata biodiesel along with diesel (CPD are taken for the experimental analysis. Experiments are conducted using a single cylinder direct-injection diesel engine with different loads at rated 3000 rpm. The engine characteristics of the two sets of double biodiesel blends are compared. For the maximum load, the value of Specific Fuel consumption and thermal efficiency of CPD-1 blend (10:10:80 is close to the diesel values. CPD blends give better engine characteristics than PMD blends. The blends of CPD are suitable alternative fuel for diesel in stationary/agricultural diesel engines.

  8. Chitosan films and blends for packaging material.

    Science.gov (United States)

    van den Broek, Lambertus A M; Knoop, Rutger J I; Kappen, Frans H J; Boeriu, Carmen G

    2015-02-13

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory and non-depleting protection agents for application in films, coatings and packaging. In food packaging, antimicrobial effects add up to the barrier properties of the materials, to increase the shelf life and product quality. Chitosan is a natural bioactive polysaccharide with intrinsic antimicrobial activity and, due to its exceptional physicochemical properties imparted by the polysaccharide backbone, has been recognized as a natural alternative to chemically synthesized antimicrobial polymers. This, associated with the increasing preference for biofunctional materials from renewable resources, resulted in a significant interest on the potential for application of chitosan in packaging materials. In this review we describe the latest developments of chitosan films and blends as packaging material.

  9. Can Nanorods Emulsify Immiscible Polymer Blends?

    Science.gov (United States)

    Hore, Michael J. A.

    2005-03-01

    The addition of nanoscale rods to immiscible binary polymer blends has a pronounced effect on the dynamics of phase separation. The results of computer simulations of the Dissipative Particle Dynamics (DPD) model in three dimensions (3D) indicate that when nanorods prefer one of two components in an immiscible binary polymer blend, the rate of phase separation decreases when the volume fraction of nanorods is increased, or as the aspect ratio (L/D) of the rods is increased. Interestingly, anisotropic nanoparticles have a much more pronounced effect on phase separation dynamics in the system when compared to the effects of spherical nanoparticles, which, generically, do not alter the characteristics of the kinetics in the system. In particular, it may be the case that at high volume fractions -- or alternatively, low volume fractions and large aspect ratio of nanorods -- the system may undergo micro-phase separation only, indicating that the nanorods may be excellent emulsifying agents.

  10. Polymer blend compositions and methods of preparation

    Science.gov (United States)

    Naskar, Amit K.

    2016-09-27

    A polymer blend material comprising: (i) a first polymer containing hydrogen bond donating groups having at least one hydrogen atom bound to a heteroatom selected from oxygen, nitrogen, and sulfur, or an anionic version of said first polymer wherein at least a portion of hydrogen atoms bound to a heteroatom is absent and replaced with at least one electron pair; (ii) a second polymer containing hydrogen bond accepting groups selected from nitrile, halogen, and ether functional groups; and (iii) at least one modifying agent selected from carbon particles, ether-containing polymers, and Lewis acid compounds; wherein, if said second polymer contains ether functional groups, then said at least one modifying agent is selected from carbon particles and Lewis acid compounds. Methods for producing the polymer blend, molded forms thereof, and articles thereof, are also described.

  11. Genistein Modified Polymer Blends for Hemodialysis Membranes

    Science.gov (United States)

    Chang, Teng; Kyu, Thein; Define, Linda; Alexander, Thomas

    2012-02-01

    A soybean-derived phytochemical called genistein was used as a modifying agent to polyether sulfone/polyvinyl pyrrolidone (PES/PVP) blends to produce multi-functional hemodialysis membranes. With the aid of phase diagrams of PES/PVP/genistein blends, asymmetric porous membranes were fabricated by coagulating in non-solvent. Both unmodified and genistein modified PES/PVP membranes were shown to be non-cytotoxic to the blood cells. Unmodified PES/PVP membranes were found to reduce reactive oxygen species (ROS) levels, whereas the genistein modified membranes exhibited suppression for ˜60% of the ROS levels. Also, the genistein modified membranes revealed significant suppression of pro-inflammatory cytokines: IL-1β, IL-6, and TNF-α. Moreover, addition of PVP to PES showed the reduced trend of platelet adhesion and then leveled off. However, the modified membranes exhibited suppression of platelet adhesion at low genistein loading, but beyond 15 wt%, the platelet adhesion level rised up.

  12. How Pure Components Control Polymer Blend Miscibility

    Science.gov (United States)

    White, Ronald; Lipson, Jane; Higgins, Julia

    2012-02-01

    We present insight into some intriguing relationships revealed by our recent studies of polymer mixture miscibility. Applying our simple lattice-based equation of state, we discuss some of the patterns observed over a sample of experimental blends. We focus on the question of how much key information can one determine from a knowledge of just the pure components only, and further, on the role of separate enthalpic and entropic contributions to the miscibility behavior. One interesting correlation connects the value of the difference in pure component energetic parameters with that of the mixed segment interactions, suggesting new possibilities for predictive modeling. We also show how in some cases these two parameter groupings act as separate controls determining the entropy and enthalpy of mixing. Also discussed are the different patterns exhibited for UCST-type and LCST-type blends, these being revealed in some cases by simple examination of the underlying microscopic parameters.

  13. MISCIBILITY IN COPOLYMER/HOMOPOLYMER BLENDS

    Institute of Scientific and Technical Information of China (English)

    JIANG Ming

    1988-01-01

    In order to study the miscibility of a copolymer with its corresponding homopolymers, varieties of multicomponent polymers including simple graft, multibranch, diblock, triblock and four-arm block copolymers and so-called ABCPs were synthesized and characterized. The morphologies of the blends comprising the covolymers and the corresponding homopolymers were examined by electron microscopy. It is concluded that beeides molecular weight, architecture of a copolymers has apparent effect on the miscibility, i.e. the more complex is molecular architecture, the greater is conformation restriction in microdomain formation and the less is solubility of homopolymer in corresponding domains. In addition, a density gradient model is suggested for describing the segment distribution of the bound and free chains in block-homopolymer systems. Using this model, Helfand's theory is extended to the blends of copolymer and homopolymer predicting the miscibility which is in good agreement with the experimental results.

  14. Phase morphological study on SEBS compatibilized PS/LDPE blends

    Directory of Open Access Journals (Sweden)

    Chatchai Kunyawut

    2014-09-01

    Full Text Available The co-continuous phase morphology of polystyrene (PS/low density polyethylene (LDPE blends compatibilized with poly(styrene-block-ethylene/butylene-block-styrene triblock copolymers (SEBS with varying molecular weights has been investigated. The blend samples were prepared in a mini-twin screw extruder. The barrel length and diameter are 224 and 16 mm, respectively. The diameter of the capillary die is 1 mm. The concentration of the blends was 70/30 wt% of PS/LDPE while that of the SEBS used was 5 wt% of the blend. The mixing temperatures used were 180, 250, and 280o C, and a screw speed of 60 rpm. The morphology of the blends was investigated using an AFM technique. Average droplet diameters of the blend samples were determined using an OM technique. The co-continuous morphology has not been obtained in all the blends, although the mixing temperature used is as high as 280o C. The experimental results indicated that the model prediction of the co-continuous morphology proposed by Willemse and co-worker was not applicable to the blend systems studied. Only droplet-type dispersion was observed. This is considered to arise from the processing conditions and the mixing device used. The blend compatibilized with the high molecular weight SEBS had higher dispersed phase size than that of the blend compatibilized with the medium and low molecular weight SEBSs. This behaviour is likely to arise from coalescence during melt processing.

  15. Engineers Create Bone that Blends into Tendons

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Engineers at Georgia Tech have used skin cells to create artificial bones that mimic the ability of natural bone to blend into other tissues such as tendons or ligaments. The artificial bones display a gradual change from bone to softer tissue rather than the sudden shift of previously developed artificial tissue, providing better integration with the body and allowing them to handle weight more successfully.

  16. Blended learning. Conceptos básicos

    Directory of Open Access Journals (Sweden)

    Antonio Bartolomé Pina

    2004-01-01

    Full Text Available En los últimos dos años ha aparecido un nuevo concepto que surge con fuerza en el ámbito de la formación: «Blended Learning». Literalmente podríamos traducirlo como «aprendizaje mezclado» y la novedad del término no se corresponde con la tradición de las prácticas que encierra. Otras denominaciones se han utilizado antes para la misma idea. Y a veces otras ideas se están utilizando para esta misma denominación. ¿Estamos ante un simple recurso de propaganda y venta? ¿Aporta algo a nuestras acción formativa? Este artículo trata de ayudar a comprender que se entiende por «Blended Learning» y a entresacar algunas de las aportaciones que nos pueden enriquecer. Tras estudiar el blended learning como respuesta a los problemas que encuentra el elearning y la enseñanza tradicional, se analizan sus posibilidades y sus características. El artículo termina con una reflexión sobre la razón de la necesidad de este modelo más allá de los motivos economicistas o didácticos.

  17. Engineering Polymer Blends for Impact Damage Mitigation

    Science.gov (United States)

    Gordon, Keith L.; Smith, Russell W.; Working, Dennis C.; Siochi, Emilie J.

    2016-01-01

    Structures containing polymers such as DuPont's Surlyn® 8940, demonstrate puncture healing when impacted by a 9 millimeter projectile traveling from speeds near 300 meters per second (1,100 feet per second) to hypervelocity impacts in the micrometeoroid velocity range of 5 kilometers per second (16,000 feet per second). Surlyn® 8940 puncture heals over a temperature range of minus 30 degrees Centigrade to plus 70 degrees Centigrade and shows potential for use in pressurized vessels subject to impact damage. However, such polymers are difficult to process and limited in applicability due to their low thermal stability, poor chemical resistance and overall poor mechanical properties. In this work, several puncture healing engineered melt formulations were developed. Moldings of melt blend formulations were impacted with a 5.56 millimeter projectile with a nominal velocity of 945 meters per second (3,100 feet per second) at about 25 degrees Centigrade, 50 degrees Centigrade and 100 degrees Centigrade, depending upon the specific blend being investigated. Self-healing tendencies were determined using surface vacuum pressure tests and tensile tests after penetration using tensile dog-bone specimens (ASTM D 638-10). For the characterization of tensile properties both pristine and impacted specimens were tested to obtain tensile modulus, yield stress and tensile strength, where possible. Experimental results demonstrate a range of new puncture healing blends which mitigate damage in the ballistic velocity regime.

  18. Fuel briquettes from biomass-lignite blends

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, S.; Haykiri-Acma, H.; Sesen, K.; Kuecuekbayrak, S. [Chemical Engineering Department, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, Maslak, 80626 Istanbul (Turkey)

    2001-08-01

    In this study, a western Turkish lignite (Kuetahya-Seyitoemer) was blended with some biomass samples such as molasses, pine cone, olive refuse, sawdust, paper mill waste, and cotton refuse, and these blends was used in the production of fuel briquettes. Blends were subjected to briquetting pressures between 50 and 250 MPa; the ratio of biomass to lignite was changed between 0 and 30 wt.%. The mechanical strength of obtained briquettes was investigated considering shatter index and compressive strength. Effects of the ratio of biomass to lignite and applied pressure on the strength of the briquettes were examined. This study indicated that the mechanical strength of the briquettes produced from Kuetahya-Seyitoemer lignite can be improved by adding some biomass samples. For example, the presence of paper mill waste increased the shatter index of the briquettes obtained. Similarly, sawdust and paper mill waste increased compressive strength of the briquettes. Water resistance of the briquettes can be augmented by adding olive refuse, cotton refuse, pine cone or paper mill waste.

  19. Supramolecular assembly in telechelic polymer blends

    Science.gov (United States)

    Elliott, R.; Fredrickson, Glenn H.

    2009-10-01

    Equilibrium, supramolecular assembly in melt blends of two species of telechelic polymers with reversible bonding sites at both ends is theoretically investigated. The bonding between polymers, whether between like or dislike chains, is controlled by affinities of chain bonding set by specified bond energies. Low affinities, or low overall bond strength, results in a monodisperse population of unlinked chains while larger affinities cause longer chains to assemble, forming a polydisperse blend. We investigate sequentially blends with only homobonding (like chain), only heterobonding (dislike chain), and finally a mixed homo- and heterobonding melt. In the first case, the effects of longer chain assembly and polydispersity in a homogeneous melt and its bulk demixing transition are explored. In contrast with the homobonding case, large heterobonding affinities cause alternating blocks to assemble into multiblock copolymers, which can lead to mesophases. The weak bonding region between bulk phase separation and mesophase stability is investigated and a novel Lifshitz point is found indicating a region prone to emulsify. Mixed homo- and heterobonding systems are also examined. Polymeric segments of both species are modeled as flexible Gaussian threads and nonspecific interactions between dissimilar blocks are contactlike Flory-Huggins repulsions. The melts are assumed to be incompressible and all calculations are carried out within mean-field theory. A new integral equation formalism is developed for enumerating all linear species in these complex supramolecular systems, and the random phase approximation and numerical self-consistent field theory are invoked in this context to map out a variety of phase diagrams.

  20. Tough blends of polylactide and castor oil.

    Science.gov (United States)

    Robertson, Megan L; Paxton, Jessica M; Hillmyer, Marc A

    2011-09-01

    Poly(l-lactide) (PLLA) is a renewable resource polymer derived from plant sugars with several commercial applications. Broader implementation of the material is limited due to its inherent brittleness. We show that the addition of 5 wt % castor oil to PLLA significantly enhances the overall tensile toughness with minimal reductions in the modulus and no plasticization of the PLLA matrix. In addition, we used poly(ricinoleic acid)-PLLA diblock copolymers, synthesized entirely from renewable resources, as compatibilizers for the PLLA/castor oil blends. Ricinoleic acid, the majority fatty acid comprising castor oil, was polymerized through a lipase-catalyzed condensation reaction. The resulting polymers contained a hydroxyl end-group that was subsequently used to initiate the ring-opening polymerization of l-lactide. The binary PLLA/castor oil blend exhibited a tensile toughness seven times greater than neat PLLA. The addition of block copolymer allowed for control over the morphology of the blends, and even further improvement in the tensile toughness was realized-an order of magnitude larger than that of neat PLLA.

  1. Recovery of blended product pipeline slops

    Energy Technology Data Exchange (ETDEWEB)

    Sloley, A.W. [Process Consulting Services, Inc., Houston, TX (United States)

    1996-09-01

    Both product pipeline operation and terminal blending often generate slops consisting of mixed hydrocarbon streams. Typical slops dispositions include local burning of the fuel for heat or power generation or reshipment to a refinery in a crude stream. Both of these dispositions can incur significant economic penalties. An alternative is the use of a small local plant for the separation of the streams back into pipeline products. This is achievable as long as blend stocks rather then final products containing performance additives are being separated. Final products (gasoline, diesel) contain additives and blending components difficult to handle within the constraints of a small process unit. A proposed multi-product separation unit is presented. The case investigated shows the process configuration required for a unit to process a range of mixtures containing material from LPG to atmospheric gas oil. The material presented includes the plant flow scheme, identification of major equipment, and overall sizing of major equipment. The study results summarize the investment and operating costs of the unit compared to the values of the recoverable products.

  2. Tough Blends of Polylactide and Castor Oil

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Megan L.; Paxton, Jessica M.; Hillmyer, Marc A. (UMM)

    2012-10-10

    Poly(l-lactide) (PLLA) is a renewable resource polymer derived from plant sugars with several commercial applications. Broader implementation of the material is limited due to its inherent brittleness. We show that the addition of 5 wt % castor oil to PLLA significantly enhances the overall tensile toughness with minimal reductions in the modulus and no plasticization of the PLLA matrix. In addition, we used poly(ricinoleic acid)-PLLA diblock copolymers, synthesized entirely from renewable resources, as compatibilizers for the PLLA/castor oil blends. Ricinoleic acid, the majority fatty acid comprising castor oil, was polymerized through a lipase-catalyzed condensation reaction. The resulting polymers contained a hydroxyl end-group that was subsequently used to initiate the ring-opening polymerization of L-lactide. The binary PLLA/castor oil blend exhibited a tensile toughness seven times greater than neat PLLA. The addition of block copolymer allowed for control over the morphology of the blends, and even further improvement in the tensile toughness was realized - an order of magnitude larger than that of neat PLLA.

  3. An Summarization on Blended Learning%Blended Learning初步研究

    Institute of Scientific and Technical Information of China (English)

    田世生; 傅钢善

    2004-01-01

    混合式学习(Blended Learning)的核心目的就是要将传统的课堂式学习和e-Learning的优势相结合.从2001年国外e-Learning开始进入低潮后,国外教育技术界和企业培训界便试图用混合式学习来辅助和改造传统的e-Learning.现在混合式学习已成为教育技术界高度关注的热点.本文拟从Blended Learning的基本问题、设计一个Blended Learning课程的方法以及其对教育技术学带来的反思等方面作一个综述.

  4. The Optimum Blend: Affordances and Challenges of Blended Learning For Students

    Directory of Open Access Journals (Sweden)

    Nuray Gedik

    2012-07-01

    Full Text Available The purpose of this study was to elicit students’ perceptions regarding the most facilitative and most challenging features (affordances and barriers in a blended course design. Following the phenomenological approach of qualitative inquiry, data were collected from ten undergraduate students who had experiences in a blended learning environment. Data were collected from the students’ weekly reflection papers, interviews with students, and documents, and analyzed by structurally and texturally describing the resulting experiences and perceptions. The findings of the study indicate that used together, online and face-to-face course structures offer several opportunities and challenges for students. The participating students mentioned interaction and communication opportunities, increased motivation, increased opportunities to voice their opinions, and reinforcement of learning as the affordances in the blended learning environment. The barriers included increased workload, cultural and technical barriers, and the inter-dependence of the two environments. Implications and suggestions are offered for instructors in higher education settings.

  5. Radiation processing of thermoplastic starch by blending aromatic additives: Effect of blend composition and radiation parameters

    Science.gov (United States)

    Khandal, Dhriti; Mikus, Pierre-Yves; Dole, Patrice; Coqueret, Xavier

    2013-03-01

    This paper reports on the effects of electron beam (EB) irradiation on poly α-1,4-glucose oligomers (maltodextrins) in the presence of water and of various aromatic additives, as model blends for gaining a better understanding at a molecular level the modifications occurring in amorphous starch-lignin blends submitted to ionizing irradiation for improving the properties of this type of bio-based thermoplastic material. A series of aromatic compounds, namely p-methoxy benzyl alcohol, benzene dimethanol, cinnamyl alcohol and some related carboxylic acids namely cinnamic acid, coumaric acid, and ferulic acid, was thus studied for assessing the ability of each additive to counteract chain scission of the polysaccharide and induce interchain covalent linkages. Gel formation in EB-irradiated blends comprising of maltodextrin was shown to be dependent on three main factors: the type of aromatic additive, presence of glycerol, and irradiation dose. The chain scission versus grafting phenomenon as a function of blend composition and dose were studied using Size Exclusion Chromatography by determining the changes in molecular weight distribution (MWD) from Refractive Index (RI) chromatograms and the presence of aromatic grafts onto the maltodextrin chains from UV chromatograms. The occurrence of crosslinking was quantified by gel fraction measurements allowing for ranking the cross-linking efficiency of the additives. When applying the method to destructurized starch blends, gel formation was also shown to be strongly affected by the moisture content of the sample submitted to irradiation. The results demonstrate the possibility to tune the reactivity of tailored blend for minimizing chain degradation and control the degree of cross-linking.

  6. Cocontinuous polymer blends: The role of block copolymer in blend morphology evolution

    Science.gov (United States)

    Bell, Joel Richard

    Cocontinuous morphologies are distinguished by the mutual interpenetration of two polymer phases and allow for enhanced mechanical properties, static charge dissipation, and barrier properties. Cocontinuous morphologies form over a range of compositions, depending largely on mixing history and the relative polymer viscosities, elasticities, and interfacial tension. Because cocontinuous morphologies are thermodynamically unstable, they will coarsen when held above their glass or melt transition temperature. Since the unique properties of these blends depend directly on the continuous nature of the microstructure and its phase size, stabilization of the cocontinuous morphology is extremely important. To address this challenge, compatibilizers, e.g. block copolymers (bcp), are often added to hinder phase coarsening in blends of immiscible polymers and can improve bonding at interfaces. The effects of bcp on the cocontinuous morphology of polystyrene (PS)/polyethylene (PE) and PS/poly(methyl methacrylate) (PMMA) blends were studied using scanning electron microscopy (SEM) with image analysis, 3D imaging, mercury porosimetry, solvent extraction, and rheology. It was shown that diblock copolymers were able to suppress coarsening during annealing in cocontinuous PS/PE and PS/PMMA blends. Bcp effectiveness was dependent on molecular weight, concentration, and architecture. Self consistent mean field theory and bending elasticity theory were used to estimate the proper bcp architecture for maximum reduction in interfacial tension; experimental results agreed well with the theory. In addition to slowing coarsening, bcp was shown to widen the range of cocontinuity for both the PS/PE and PS/PMMA systems. To aid determination of the range of cocontinuity, a new technique for analyzing SEM micrographs was developed. The new technique classifies blend morphology according to the normalized fraction of drops present in the 2D microstructure. It was found that a blend becomes

  7. FTIR Study of Enhanced Polymeric Blend Membrane with Amines

    Directory of Open Access Journals (Sweden)

    Asim Mushtaq

    2014-03-01

    Full Text Available In this study, research will be carried out to identify the functional group behavior of glassy and rubbery polymeric blend membrane with amines. Polymeric blend membranes with different blending ratios were prepared and the developed membranes were characterized by FTIR to see the effect of blend ratio on different functional groups. The developed membranes are flat dense sheet membrane of 20% wt/wt. The pure and blend membrane polysulfone, polyethersulfone, polyvinyl acetate with different composition, with 10% methyl diethanol amine, mono ethanol amine, diethanol amine are developed with dimethyl acetamide solvent. Fourier Transform Infrared (FTIR spectroscopy was utilized to study the interaction between two polymers and to analyze the type of bonding present. To observed frequencies were assigned to various mode of vibration in terms of fundamentals and combination. These spectral changes indicated the existence of molecular interaction among the enhanced polymeric blends; highlight the compatible nature among each other.

  8. Studies on poly (hydroxy alkanoates)/(ethylcellulose) blends

    Indian Academy of Sciences (India)

    Vaishali Suthar; Arun Pratap; Heta Raval

    2000-06-01

    Biodegradable polymers represent one of the most significant area of research today. Among these polymers, poly (-hydroxy butyrate co '-hydroxy valerate) i.e. PHBV have received special attention because of their unique combination of properties. They are perfectly biocompatible, biodegradable polymers and can be processed by any conventional technique. In the present study an attempt has been made to develop the biodegradable blends of PHBV by blending them with ethyl cellulose (EC). Ethyl cellulose has been selected to monitor the biodegradation rate of PHBV and also for making the blends cost effective. The blends are thoroughly characterized for their compatibility, by the measurement of viscosity of blends and through FT-IR. Various applications of PHBV/EC blend in agriculture and pharmaceutical industries are being explored.

  9. Blending in Gravitational Microlensing Experiments: Source Confusion And Related Systematics

    CERN Document Server

    Smith, Martin C; Mao, Shude; Sumi, Takahiro

    2007-01-01

    Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty when determining the lensing properties of events towards the Galactic centre. After demonstrating empirical cases of blending we utilize Monte Carlo simulations to probe the effects of blending. We generate artificial microlensing events using an HST luminosity function convolved to typical ground-based seeing, adopting a range of values for the stellar density and seeing. We find that a significant fraction of bright events are blended, contrary to the oft-quoted assumption that bright events should be free from blending. We probe the effect that this erroneous assumption has on both the observed event timescale distribution and the optical depth, using realistic detection criteria relevent to the different surveys. Importantly, under this assumption the latter quantity ...

  10. Preparation and characterization of chitosan - polystyrene polymer blends

    Science.gov (United States)

    Mascarenhas, N. P.; Gonsalves, R. A.; Goveas, J. J.; Shetty, T. C. S.; Crasta, V.

    2016-05-01

    To enhance the physical and mechanical properties of Chitosan (CS) and to improve the functionality of CS towards some specific applications, we have blended CS with polystyrene (PS) to form blended films. The Fourier Transform Infrared Spectroscopy (FT-IR) has been performed on the prepared films to confirm functional groups and formation of the blends. Thermal analysis (TGA and DSC) is carried out to study thermal stability of the blended films. From X-ray diffraction (XRD) studies, the material reveals amorphous nature and hence it may be used for adsorption process. The versatility of the blends, such as film-forming ability, hydrophilicity, biodegradability and biocompatibility are comparable with the existing blends.

  11. METHOD TO EXTRACT BLEND SURFACE FEATURE IN REVERSE ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    Lü Zhen; Ke Yinglin; Sun Qing; Kelvin W; Huang Xiaoping

    2003-01-01

    A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.

  12. Blending effects on coal burnout and NO emissions

    Energy Technology Data Exchange (ETDEWEB)

    B. Arias; R. Backreedy; A. Arenillas; J.M. Jones; F. Rubiera; M. Pourkashanian; A. Williams; J.J. Pis [Instituto Nacional del Carbon, CSIC Oviedo (Spain)

    2003-07-01

    In this work, the combustion behaviour of individual coals of different rank and their blends was evaluated. The study was focused on burnout and NO emissions during blend combustion. Preliminary combustion tests of the coals and their blends were carried out in a thermogravimetric analyser (TGA). Some characteristic temperatures were obtained to evaluate the combustibility of the samples. These temperatures indicate an improvement in the combustibility of the less reactive coal when it is blended. An entrained flow reactor (EFR) was employed to study the behaviour of the samples at high heating rates and short residence times. Burnout and NO emissions were measured during EFR combustion tests. In some blends the results can be predicted from the weighted average of the values of the individual coals. However, other blends show an increase, from the averaged values, in burnout and especially in NO emissions. 14 refs., 10 figs., 3 tabs.

  13. Alcohol-to-Jet (ATJ) Fuel Blending Study

    Science.gov (United States)

    2015-09-01

    Synthetic Fuel, JP-8, diesel engine , combustion 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF...stock into JP-8 in order to understand the effect ATJ fuel blends will have on ground vehicle engines and support equipment. This subtask under Work...paraffinic ATJ blending stock into JP-8 in order to understand the effect ATJ fuel blends will have on ground vehicle engines and support equipment. This

  14. Blend for visual studio 2012 by example beginner's guide

    CERN Document Server

    Shukla, Abhishek

    2015-01-01

    This book is aimed at developers and designers who are new to Blend and looking to learn Blend, not just practically, but also conceptually. This book does not assume any knowledge about Blend on the part of developers; however, some experience in design or development might be useful in understanding the concepts faster, but this book explains everything very simply so that you are able to understand everything with little or no effort.

  15. Effectiveness of Low Temperature Additives for Biodiesel Blends

    Science.gov (United States)

    2012-06-30

    UNCLASSIFIED EFFECTIVENESS OF LOW TEMPERATURE ADDITIVES FOR BIODIESEL BLENDS INTERIM REPORT TFLRF No. 428 by Steven R...Do not return it to the originator. UNCLASSIFIED UNCLASSIFIED EFFECTIVENESS OF LOW TEMPERATURE ADDITIVES FOR BIODIESEL BLENDS...17-2010 – 06-30-2012 4. TITLE AND SUBTITLE Effectiveness of Low Temperature Additives for Biodiesel Blends 5a. CONTRACT NUMBER W56HZV-09-C-0100

  16. Blending Learning与创新人才培养

    Institute of Scientific and Technical Information of China (English)

    石小云; 肖伟

    2006-01-01

    Blending Learning这一新概念的提出和被广泛认同,真正深化了学校教学改革,达到培养创新人才的目标.本文从Blending Learning和创新人才的涵义及关系探讨了Blending Learning对培养创新人才的重要意义.

  17. READINESS FOR BLENDED LEARNING: UNDERSTANDING ATTITUDE OF UNIVERSITY STUDENTS

    Directory of Open Access Journals (Sweden)

    Chun Meng Tang

    2013-12-01

    Full Text Available Information technology (IT has provided new means for learning delivery outside of conventional classrooms. Leveraging on IT, blended learning is an approach which takes advantage of the best that both the classroom and online learning can provide. To help institutions of higher learning (IHLs improve their understanding of how students view blended learning and formulate a strategy to successfully implement blended learning, the main objective of this paper is to examine how the attitude of students towards different learning aspects could influence their readiness for blended learning. We conceptualized six learning aspects in a research model and then collected responses from 201 full-time undergraduate students to validate the model. Analyses revealed three key findings. First, the use of technology in education was not a hindrance to the students. Second, blended learning adaptability, which was modelled as a second-order formative construct and formed by four first-order reflective constructs—attitude towards online learning, study management, online interaction, and learning flexibility—had a positive relationship with student readiness for blended learning. Third, attitude towards classroom learning had a negative relationship with student readiness for blended learning. An understanding of student attitude towards different learning aspects can be critical in the assessment of student readiness for blended learning, which is a prerequisite for successful implementation of blended learning.

  18. A BLENDED LEARNING MODEL FOR TEACHING PRACTICE COURSE

    Directory of Open Access Journals (Sweden)

    Mustafa CANER

    2010-07-01

    Full Text Available The aim of the present study is to introduce a blended learning environment and a model for pre-service teaching practice course in English Language Teacher Training Program at Anadolu University. It is supposed that providing a blended learning environment for teaching practice course would improve the practice and contribute to the professional growth of pre-service teachers. Since it will increase the contact hours among students and university supervisors and facilitate peer feedback among pre-service teachers, which in turn, create a productive learning environment for them. Thus, the present paper aimed at providing a blended learning model for teaching practice courses at teacher training institutions and give impetus for the researchers or instructors who would like to implement blended learning in their own teaching environments. Additionally, the present study intends to contribute expanded understanding to the way blending the learning environments, and contribute additional understanding to the knowledge base about the implementation of blended learning for a teaching practice course. Finally, through illustrating a blended learning environment for teaching practice course, it is hoped that this study might contribute to the growing body of knowledge of blended delivery and blended learning in higher education.

  19. Blended working: for whom it may (not work.

    Directory of Open Access Journals (Sweden)

    Nico W Van Yperen

    Full Text Available Similarly to related developments such as blended learning and blended care, blended working is a pervasive and booming trend in modern societies. Blended working combines on-site and off-site working in an optimal way to improve workers' and organizations' outcomes. In this paper, we examine the degree to which workers feel that the two defining features of blended working (i.e., time-independent working and location-independent working enhance their own functioning in their jobs. Blended working, enabled through the continuing advance and improvement of high-tech ICT software, devices, and infrastructure, may be considered beneficial for workers' perceived effectiveness because it increases their job autonomy. However, because blended working may have downsides as well, it is important to know for whom blended working may (not work. As hypothesized, in a sample of 348 workers (51.7% women, representing a wide range of occupations and organizations, we found that the perceived personal effectiveness of blended working was contingent upon workers' psychological need strength. Specifically, the perceived effectiveness of both time-independent working and location-independent working was positively related to individuals' need for autonomy at work, and negatively related to their need for relatedness and need for structure at work.

  20. Damage initiated self-healing in ionomer blends

    Science.gov (United States)

    Rahman, Md. Arifur; Penco, Maurizio; Spagnoli, Gloria; Peroni, Isabella; Ramorino, Giorgio; Sartore, Luciana; Bignotti, Fabio; Landro, Luca Di

    2012-07-01

    The development and understanding of self-healing mechanisms have been investigated in blends of ionomers (Poly(ethyelene-co-methacrylic acid), sodium & zinc ions) (EMNa & EMZn) containing both elastomers (Epoxidized natural rubbers (ENR) and cis-1,4-Polyisoprene (PISP)) and crystalline component (Poly(vinly alcohol-co-ethylene) [PVAcE]) as secondary phases. All the blends were prepared by melt-blending and self-healing behavior was studied in ballistic puncture tests. Self-healing behavior of each material was evaluated by observing the impact zones under a stereo-optical microscope and the micrographic results were further supported by the fluid flow test in the punctured zones. Interestingly, ENR50 blends of sodium ion containing ionomers exhibited complete self-repairing behavior while zinc ion containing ionomer showed limited mending but EMNa/ENR25 and EMNa/PISP blends did not show any self-healing behavior following the damage. On the other hand, a composition dependent healing behavior was observed in the EMNa/PVAcE blends where healing was observed up to 30wt% PVAcE containing blends. The chemical structure studied by FTIR analysis showed that both ion content of ionomer and functionality of ENR have significant influence on the self-repairing behavior of blends. TEM analysis revealed that self-healing occurs in the blends when the dispersed phase has a dimension of 100 to 400 nm.

  1. PHA-rubber blends: synthesis, characterization and biodegradation.

    Science.gov (United States)

    Bhatt, Rachana; Shah, Dishma; Patel, K C; Trivedi, Ujjval

    2008-07-01

    Medium chain length polyhydroxyalkanoates (mcl-PHA) and different rubbers; namely natural rubber, nitrile rubber and butadiene rubber were blended at room temperature using solution blending technique. Blends constituted 5%, 10% and 15% of mcl-PHA in different rubbers. Thermogravimetric analysis of mcl-PHA showed the melting temperature of the polymer around 50 degrees C. Thermal properties of the synthesized blend were studied by Differential Scanning Calorimetry which confirmed effective blending between the polymers. Blending of mcl-PHA with natural rubber led to the synthesis of a different polymer having the melting point of 90 degrees C. Degradation studies of the blends were carried out using a soil isolate, Pseudomonas sp. 202 for 30 days. Extracellular protein concentration as well as OD660 due to the growth of Pseudomonas sp. 202 was studied. The degradation of blended plastic material, as evidenced by % weight loss after degradation and increase in the growth of organism correlated with the amount of mcl-PHA present in the sample. Growth of Pseudomonas sp. 202 resulted in 14.63%, 16.12% and 3.84% weight loss of PHA:rubber blends (natural, nitrile and butadiene rubber). Scanning electron microscopic studies after 30 days of incubation further confirmed biodegradation of the films.

  2. Silk fibroin and sodium alginate blend: Miscibility and physical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Agostini de Moraes, Mariana; Silva, Mariana Ferreira; Weska, Raquel Farias; Beppu, Marisa Masumi, E-mail: beppu@feq.unicamp.br

    2014-07-01

    Films of silk fibroin (SF) and sodium alginate (SA) blends were prepared by solution casting technique. The miscibility of SF and SA in those blends was evaluated and scanning electron microscopy (SEM) revealed that SF/SA 25/75 wt.% blends underwent microscopic phase separation, resulting in globular structures composed mainly of SF. X-ray diffraction indicated the amorphous nature of these blends, even after a treatment with ethanol that turned them insoluble in water. Thermal analyses of blends showed the peaks of degradation of pristine SF and SA shifted to intermediate temperatures. Water vapor permeability, swelling capacity and tensile strength of SF films could be enhanced by blending with SA. Cell viability remained between 90 and 100%, as indicated by in vitro cytotoxicity test. The SF/SA blend with self-assembled SF globules can be used to modulate structural and mechanical properties of the final material and may be used in designing high performance wound dressing. - Highlights: • Blend films of fibroin and alginate were prepared with microscopic phase separation; • Self-assembled globular microdomains were mainly composed by fibroin; • It was possible to obtain a film with better mechanical and physical properties; • Blend films of fibroin and alginate represent a novel material in biomaterials field.

  3. EFFECT of blend ratio and compatibilizer on solution casted treated waste natural rubber latex/polystyrene blends

    Directory of Open Access Journals (Sweden)

    Orathai Boondamnoen

    2013-10-01

    Full Text Available Natural rubber latex waste (WL was treated with natural rubber latex (NRL prior to blend with polystyrene. Differentblend compositions of treated waste natural rubber latex (TWL and PS were carried out through solution blending. Tensileand tear properties were investigated. The compatibility improvement of the 70/30 TWL/PS blends was further investigatedusing styrene butadiene rubber (SBR and styrene graft natural rubber (SNR as compatibilizer. The mechanical properties forTWL/PS blends were improved at 15 phr of SNR.

  4. Blending toward Competency. Early Patterns of Blended Learning and Competency-Based Education in New Hampshire

    Science.gov (United States)

    Freeland, Julia

    2014-01-01

    As the education field strives to differentiate and personalize learning to cater to each student, two related movements are gaining attention: competency-based education and blended learning. In competency-based models, students advance on the basis of mastery, rather than according to the traditional methods of counting progress in terms of time…

  5. Teaching European Studies: A Blended Learning Approach

    Directory of Open Access Journals (Sweden)

    Alina Christova

    2011-12-01

    Full Text Available This paper will be looking into the teaching method developed by the Institute for European Studies in Brussels, combining an e-learning tool- the E-modules- with face-to-face training sessions and webinars. The main aim is to analyse the three different components of this “blended learning” pedagogical approach, as well as the way they complement each other and to address a few of the challenges that have emerged from the experience of working with them so far. The E-modules are an e-learning platform that has been designed with the purpose of offering a structured and interactive way of learning how the European Union functions. The face-to-face training component currently takes the form of three days in-house seminars, covering in an intensive manner the most important areas of the curriculum. The lectures are held by a mix of academics and practitioners, hereby ensuring a balanced approach, in which theory and practice come together to facilitate the learning experience. The third element of the “blended learning” method is placed in-between online and face-to-face learning: interactive seminars and debates are held online, giving the participants the chance to deepen their knowledge in certain fields of interest and to discuss the content of the course with specialists and among themselves. The mixture of delivery and interaction methods was chosen in order to accommodate a large variety of target groups, ranging from students to professionals working with EU-related issues, with different backgrounds and geographical origins. One of the main challenges is to use each medium for the functionalities it is best designed for and to ensure that the various pieces of the pedagogical puzzle fit together perfectly, while allowing the learners the flexibility that had initially directed them towards “blended learning” instead of a classical classroom approach.

  6. Cold pearl surfactant-based blends.

    Science.gov (United States)

    Crombie, R L

    1997-10-01

    Pearlizing agents have been used for many years in cosmetic formulations to add a pearlescent effect. Cold pearl surfactant-based blends are mixtures of glycol stearates and surfactants which can be blended in the cold into a wide range of personal-care formulations to create a pearlescent lustre effect. Under controlled manufacturing conditions constant viscosities and crystalline characteristics can be obtained. The development of these blends has been driven by efforts to improve the economics of adding solid pearlizing agents directly into a hot mix formulation. This paper summarizes the history of pearlizers, describes their advantages and physical chemistry of the manufacturing process. Finally some suggestions for applications are given. Les agents nacrants sont utilises depuis de nombreuses annees dans les formulations cosmetiques pour ajouter un effet nacre. Les melanges a froid a base de tensioactif nacre sont des melanges de stearates de glycol et de tensioactifs qui peuvent etre melanges a froid dans une large gamme de formulations d'hygiene personnelle pour creer un effet de lustre nacre. On peut obtenir des viscosites et des proprietes cristallines constantes avec des conditions de fabrication maitrisees. Le developpement de ces melanges a ete porte par les efforts pour ameliorer les couts de l'ajout d'agents nacrants solides directement dans une formulation melangee de l'ajout d'agents nacrants solides directement dans une formulation melangee a chaud. Cet article resume l'histoire des agents nacrants, decrit leurs avantages et al physico-chimie du procede de fabrication. On emet a la fin cetaines suggestions d'applications.

  7. TANK 21 AND TANK 24 BLEND AND FEED STUDY: BLENDING TIMES, SETTLING TIMES, AND TRANSFERS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; Leishear, R.; Poirier, M.

    2012-05-31

    The Salt Disposition Integration (SDI) portfolio of projects provides the infrastructure within existing Liquid Waste facilities to support the startup and long term operation of the Salt Waste Processing Facility (SWPF). Within SDI, the Blend and Feed Project will equip existing waste tanks in the Tank Farms to serve as Blend Tanks where salt solutions of up to 1.2 million gallons will be blended in 1.3 million gallon tanks and qualified for use as feedstock for SWPF. In particular, Tanks 21 and 24 are planned to be used for blending and transferring to the SDI feed tank. These tanks were evaluated here to determine blending times, to determine a range of settling times for disturbed sludge, and to determine that the SWPF Waste Acceptance Criteria that less than 1200 mg/liter of solids will be entrained in salt solutions during transfers from the Tank 21 and Tank 24 will be met. Overall conclusions for Tank 21 and Tank 24 operations include: (1) Experimental correction factors were applied to CFD (computational fluid dynamics) models to establish blending times between approximately two and five hours. As shown in Phase 2 research, blending times may be as much as ten times greater, or more, if lighter fluids are added to heavier fluids (i.e., water added to salt solution). As the densities of two salt solutions converge this effect may be minimized, but additional confirmatory research was not performed. (2) At the current sludge levels and the presently planned operating heights of the transfer pumps, solids entrainment will be less than 1200 mg/liter, assuming a conservative, slow settling sludge simulant. (3) Based on theoretical calculations, particles in the density range of 2.5 to 5.0 g/mL must be greater than 2-4 {micro}m in diameter to ensure they settle adequately in 30-60 days to meet the SWPF feed criterion (<1200 mg/l). (4) Experimental tests with sludge batch 6 simulant and field turbidity data from a recent Tank 21 mixing evolution suggest the solid

  8. Blend Analysis of HATNet Transit Candidates

    Directory of Open Access Journals (Sweden)

    Bakos G.Á.

    2011-02-01

    Full Text Available Candidate transiting planet systems discovered by wide-field groundbased surveys must go through an intensive follow-up procedure to distinguish the true transiting planets from the much more common false positives. Especially pernicious are configurations of three or more stars which produce radial velocity and light curves that are similar to those of single stars transited by a planet. In this contribution we describe the methods used by the HATNet team to reject these blends, giving a few illustrative examples.

  9. Initial retrieval sequence and blending strategy

    Energy Technology Data Exchange (ETDEWEB)

    Pemwell, D.L.; Grenard, C.E.

    1996-09-01

    This report documents the initial retrieval sequence and the methodology used to select it. Waste retrieval, storage, pretreatment and vitrification were modeled for candidate single-shell tank retrieval sequences. Performance of the sequences was measured by a set of metrics (for example,high-level waste glass volume, relative risk and schedule).Computer models were used to evaluate estimated glass volumes,process rates, retrieval dates, and blending strategy effects.The models were based on estimates of component inventories and concentrations, sludge wash factors and timing, retrieval annex limitations, etc.

  10. Metaphor progress report: image recall and blending

    Science.gov (United States)

    Rising, Hawley K., III

    2011-03-01

    This paper discusses a simulation that was created of a model presented three years ago at this conference of a neuron as a micro machine for doing metaphor by cognitive blending. The model background is given, the difficulties of building such a model are discussed, and a description of the simulation is given based on texture synthesis structures and texture patches. These are glued together using Formal Concept Analysis. Because of this and because of the hyperbolic and Euclidean geometry intertwining and local activation, an interesting fundamental connection between analogical processing and glial and neural processing is discovered.

  11. BLENDED TECHNOLOGY IN LEARNING FOREIGN LANGUAGES

    Directory of Open Access Journals (Sweden)

    Natalia Alexandrovna Kameneva

    2013-11-01

    Full Text Available This article analyzes the use of information technologies in the context of a blended technology approach to learning foreign languages in higher education institutions. Distance learning tools can be categorized as being synchronous (webinar, video conferencing, case-technology, chat, ICQ, Skype, interactive whiteboards or asynchronous (blogs, forums, Twitter, video and audio podcasts, wikis, on-line testing. Sociological and psychological aspects of their application in the educational process are also considered.DOI: http://dx.doi.org/10.12731/2218-7405-2013-8-41

  12. The Health Impacts of Ethanol Blend Petrol

    Directory of Open Access Journals (Sweden)

    Rosemary Wood

    2011-02-01

    Full Text Available A measurement program designed to evaluate health impacts or benefits of using ethanol blend petrol examined exhaust and evaporative emissions from 21 vehicles representative of the current Australian light duty petrol (gasoline vehicle fleet using a composite urban emissions drive cycle. The fuels used were unleaded petrol (ULP, ULP blended with either 5% ethanol (E5 or 10% ethanol (E10. The resulting data were combined with inventory data for Sydney to determine the expected fleet emissions for different uptakes of ethanol blended fuel. Fleet ethanol compatibility was estimated to be 60% for 2006, and for the air quality modelling it was assumed that in 2011 over 95% of the fleet would be ethanol compatible. Secondary organic aerosol (SOA formation from ULP, E5 and E10 emissions was studied under controlled conditions by the use of a smog chamber. This was combined with meteorological data from Sydney for February 2004 and the emission data (both measured and inventory data to model pollutant concentrations in Sydney’s airshed for 2006 and 2011. These concentrations were combined with the population distribution to evaluate population exposure to the pollutant. There is a health benefit to the Sydney population arising from a move from ULP to ethanol blends in spark-ignition vehicles. Potential health cost savings for Urban Australia (Sydney, Melbourne, Brisbane and Perth are estimated to be A$39 million (in 2007 dollars for a 50% uptake (by ethanol compatible vehicles of E10 in 2006 and $42 million per annum for a 100% take up of E10 in 2011. Over 97% of the estimated health savings are due to reduced emissions of PM2.5 and consequent reduced impacts on mortality and morbidity (e.g., asthma, cardiovascular disease. Despite more petrol-driven vehicles predicted for 2011, the quantified health impact differential between ULP and ethanol fuelled vehicles drops from 2006 to 2011. This is because modern petrol vehicles, with lower emissions than

  13. Blended learning within an undergraduate exercise physiology laboratory.

    Science.gov (United States)

    Elmer, Steven J; Carter, Kathryn R; Armga, Austin J; Carter, Jason R

    2016-03-01

    In physiological education, blended course formats (integration of face-to-face and online instruction) can facilitate increased student learning, performance, and satisfaction in classroom settings. There is limited evidence on the effectiveness of using blending course formats in laboratory settings. We evaluated the impact of blended learning on student performance and perceptions in an undergraduate exercise physiology laboratory. Using a randomized, crossover design, four laboratory topics were delivered in either a blended or traditional format. For blended laboratories, content was offloaded to self-paced video demonstrations (∼15 min). Laboratory section 1 (n = 16) completed blended laboratories for 1) neuromuscular power and 2) blood lactate, whereas section 2 (n = 17) completed blended laboratories for 1) maximal O2 consumption and 2) muscle electromyography. Both sections completed the same assignments (scored in a blinded manner using a standardized rubric) and practicum exams (evaluated by two independent investigators). Pre- and postcourse surveys were used to assess student perceptions. Most students (∼79%) watched videos for both blended laboratories. Assignment scores did not differ between blended and traditional laboratories (P = 0.62) or between sections (P = 0.91). Practicum scores did not differ between sections (both P > 0.05). At the end of the course, students' perceived value of the blended format increased (P learning key foundational content through video demonstrations before class greatly enhanced their learning of course material compared with a preassigned reading (94% vs. 78%, P Blended exercise physiology laboratories provided an alternative method for delivering content that was favorably perceived by students and did not compromise student performance.

  14. [Blending powdered antineoplastic medicine in disposable ointment container].

    Science.gov (United States)

    Miyazaki, Yasunori; Uchino, Tomonobu; Kagawa, Yoshiyuki

    2014-01-01

    On dispensing powdered antineoplastic medicines, it is important to prevent cross-contamination and environmental exposure. Recently, we developed a method for blending powdered medicine in a disposable ointment container using a planetary centrifugal mixer. The disposable container prevents cross-contamination. In addition, environmental exposure associated with washing the apparatus does not arise because no blending blade is used. In this study, we aimed to confirm the uniformity of the mixture and weight loss of medicine in the blending procedure. We blended colored lactose powder with Leukerin(®) or Mablin(®) powders using the new method and the ordinary pestle and mortar method. Then, the blending state was monitored using image analysis. Blending variables, such as the blending ratio (1:9-9:1), container size (35-125 mL), and charging rate (20-50%) in the container were also investigated under the operational conditions of 500 rpm and 50 s. At a 20% charging rate in a 35 mL container, the blending precision of the mixtures was not influenced by the blending ratio, and was less than 6.08%, indicating homogeneity. With an increase in the charging rate, however, the blending precision decreased. The possible amount of both mixtures rose to about 17 g with a 20% charging rate in a 125 mL container. Furthermore, weight loss of medicines with this method was smaller than that with the pestle and mortar method, suggesting that this method is safer for pharmacists. In conclusion, we have established a precise and safe method for blending powdered medicines in pharmacies.

  15. Pro-ELT; A Teacher Training Blended Approach

    Science.gov (United States)

    Eshtehardi, Reza

    2014-01-01

    Pro-ELT is a blended teacher training course. The aim of Pro-ELT is to strengthen English teaching and learning through a blended training approach that includes; quality face to face delivery, supported distance learning and integrated proficiency and methodology training. It delivers quality language teaching and teacher development courses to…

  16. Oxidative stability of diacylglycerol oil and butter blends containing diacylglycerols

    DEFF Research Database (Denmark)

    Kristensen, Janni Brogaard; Nielsen, Nina Skall; Jacobsen, Charlotte

    2006-01-01

    stability than their respective control TAG blends. However, they had a significantly less salty and buttery flavour, which was ascribed to a much smaller water droplet size causing a delayed sensory perception in the mouth. The butter blend with DAG oil from rapeseed had a very neutral flavour...

  17. Blended Learning in Saudi Universities: Challenges and Perspectives

    Science.gov (United States)

    Alebaikan, Reem; Troudi, Salah

    2010-01-01

    This study is an attempt to investigate the nature of obstacles and challenges encountered at Saudi universities while implementing a blended learning approach. A literature review of blended learning rationale and designs, and the status of web-based education in Saudi higher education are demonstrated. Three main challenges of applying blended…

  18. Assessing the Acceptance of a Blended Learning University Course

    Science.gov (United States)

    Tselios, Nikolaos; Daskalakis, Stelios; Papadopoulou, Maria

    2011-01-01

    Usefulness and ease of use proved to be key determinants of the acceptance and usage of e-learning. On the contrary, little is known about students' perceptions in a blended learning setting. In this paper, the Technology Acceptance Model (TAM) was utilised, in order to investigate Greek university students' attitudes toward blended learning. The…

  19. Critical crossover phenomena in compatible polymer blends studied with SANS

    DEFF Research Database (Denmark)

    Schwahn, D.; Janssen, S.; Willner, L.;

    1995-01-01

    Polymer blends show a much larger 3d-Ising regime, e.g. a much larger Ginzburg number Gi than predicted by the Ginzburg criterion. This discrepancy is supposed to be explained by the compressibility or the free volume of the blend. In this paper we present and discuss the Gi number of polymer...

  20. A Blended Mobile Learning Environment for Museum Learning

    Science.gov (United States)

    Hou, Huei-Tse; Wu, Sheng-Yi; Lin, Peng-Chun; Sung, Yao-Ting; Lin, Jhe-Wei; Chang, Kuo-En

    2014-01-01

    The use of mobile devices for informal learning has gained attention over recent years. Museum learning is also regarded as an important research topic in the field of informal learning. This study explored a blended mobile museum learning environment (BMMLE). Moreover, this study applied three blended museum learning modes: (a) the traditional…

  1. Predicting morphologies of solution processed polymer: Fullerene blends

    NARCIS (Netherlands)

    Kouijzer, S.; Michels, J.J.; Berg, M. van den; Gevaerts, V.S.; Turbiez, M.; Wienk, M.M.; Janssen, R.A.J.

    2013-01-01

    The performance of solution processed polymer:fullerene thin film photovoltaic cells is largely determined by the nanoscopic and mesoscopic morphology of these blends that is formed during the drying of the layer. Although blend morphologies have been studied in detail using a variety of microscopic

  2. Polymer blend membranes for CO2 separation from natural gas

    Science.gov (United States)

    Mukhtar, H.; Mannan, H. A.; Minh, D.; Nasir, R.; Moshshim, D. F.; Murugesan, T.

    2016-06-01

    Polymeric membranes are dominantly used in industrial gas separation membrane processes. Enhancement in membranes permeability and/or selectivity is a key challenge faced by membrane researchers. The current work represents the effect of poyetherimide blending on separation performance of polysulfone membranes. Polysulfone/poyetherimide (PSF/PEI) blend flat sheet dense membranes were synthesized and tested for permeation analysis of CO2 and CH4 gases at 6, 8 and 10 bar pressure and 25oC temperature. Morphology and thermal properties of membranes were characterized by field emission scanning electron microscope (FESEM) and thermo gravimetric analysis (TGA) respectively. Blend membranes were dense and homogeneous as deduced from FESEM analysis. Thermal stability of synthesized blend membranes was maintained by blending with PEI as characterized by TGA results. Decrease in permeability of both gases was observed by the addition of PEI due to rigidity of PEI chains. Additionally, selectivity of synthesized blend membranes was enhanced by blending PEI and blend membranes show improved selectivity over pure PSF membrane. This new material has the capability to be used as gas separation membrane material.

  3. Morphology and Compatibility of Compatibilized Polyethersulfone and Polycarbonate Blends

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-bo; JIANG Dong; WU Wei-chun; JIANG Zhen-hua

    2005-01-01

    A PES-PC(polyethersulfone-polycarbonate) multi block random copolymer was synthesized with two oligomers, polyethersulfone and polycarbonate. The effects of the copolymer, as a compatibilizer, on the morphology and compatibility of the PES-PC blends were investigated. It was found that the addition of this copolymer to the PES-PC blends could improve their compatibility.

  4. Cyber Asynchronous versus Blended Cyber Approach in Distance English Learning

    Science.gov (United States)

    Ge, Zi-Gang

    2012-01-01

    This study aims to compare the single cyber asynchronous learning approach with the blended cyber learning approach in distance English education. Two classes of 70 students participated in this study, which lasted one semester of about four months, with one class using the blended approach for their English study and the other only using the…

  5. Cognitive Advantages of Blending with Material Anchors in Energy Instruction

    Science.gov (United States)

    Close, Hunter; Close, Eleanor; Scherr, Rachel; McKagan, Sarah

    2012-03-01

    Conceptual blending theory [1] explains how the human imagination creates unreal situations that help us think about reality. In these imaginary blended situations, we establish new correspondences, interactions, and dynamics, and the outcomes of the dynamics lend insight to the nature of various real situations that were used to compose the blend. Blends are not just in the head, however; in some cases, a material system participates in the blend by lending its material structure as conceptual structure [2]. In the instructional activity Energy Theater [3], people represent units of energy and move around in order to solve puzzles of energy transfer and transformation. We use the ideas of blending and material anchors to understand how learners are able to use the representation to their cognitive advantage. [4pt] [1] Fauconnier, G. & Turner, M. (2002). The Way We Think: Conceptual Blending and the Mind's Hidden Complexities. New York: Basic Books.[0pt] [2] Hutchins, E. (2005) Material anchors for conceptual blends. Journal of Pragmatics 37, 1555-1577.[0pt] [3] Scherr, R. E., Close, H. G., McKagan, S. B., & Close, E. W. (2010) ``Energy Theater'': Using the body symbolically to understand energy. In C. Singh, M. Sabella, & S. Rebello (Eds.) 2010 PERC Proceedings. Melville, NY: AIP Press.

  6. Polypropylene–rubber blends: 5. Deformation mechanism during fracture

    NARCIS (Netherlands)

    Wal, van der A.; Gaymans, R.J.

    1999-01-01

    The deformation mechanism of polypropylene–EPDM rubber blends during fracture was studied by post-mortem SEM fractography. The deformation mechanism was determined for various blend morphologies and test conditions. Brittle fracture merely gives rise to voids, which are caused by voiding of the rubb

  7. Boron brings big benefits to bio-based blends

    Science.gov (United States)

    The solution to the problems with bio-based lubrication can be approached by a combination of blending and additive strategies. However, many additives do not show efficacy when used in bio-based lubricants. Additive addition also lowers the bio-based content of the blend, which in turn limits the a...

  8. Teaching Human Development: A Case for Blended Learning

    Science.gov (United States)

    Cottle, Nathan R.; Glover, Rebecca J.

    2011-01-01

    This article makes a case for the use of blended learning in teaching human development as a means to encourage higher-order student learning outcomes. The authors review literature regarding the use and effectiveness of blended learning, discuss an illustrative example of a redesign of a human development course, present outcomes from a…

  9. Preparation of photovoltaic cells from sexithiophene-C-60 blends

    NARCIS (Netherlands)

    Veenstra, SC; Malliaras, GG; Brouwer, HJ; Esselink, FJ; Krasnikov, VV; vanHutten, PF; Wildeman, J; Jonkman, HT; Sawatzky, GA; Hadziioannou, G; Mohlmann, GR

    1996-01-01

    Large photovoltaic responses have been recently observed in devices based on conjugated polymer-C-60 blends. Their enhanced performance, which relies on the formation of a bicontinuous network of donor-acceptor heterojunctions, is very sensitive to the morphology of the blend. In this paper, we prop

  10. Physical properties of whey protein--hydroxypropylmethylcellulose blend edible films.

    Science.gov (United States)

    Brindle, L P; Krochta, J M

    2008-11-01

    The formations of glycerol (Gly)-plasticized whey protein isolate (WPI)-hydroxypropylmethylcellulose (HPMC) films, blended using different combinations and at different conditions, were investigated. The resulting WPI: Gly-HPMC films were analyzed for mechanical properties, oxygen permeability (OP), and water solubility. Differences due to HPMC quantity and blend method were determined via SAS software. While WPI: Gly and HPMC films were transparent, blend films were translucent, indicating some degree of immiscibility and/or WPI-HPMC aggregated domains in the blend films. WPI: Gly-HPMC films were stronger than WPI: Gly films and more flexible and stretchable than HPMC films, with films becoming stiffer, stronger, and less stretchable as the concentration of HPMC increased. However, WPI: Gly-HPMC blended films maintained the same low OP of WPI: Gly films, significantly lower than the OP of HPMC films. Comparison of mechanical properties and OP of films made by heat-denaturing WPI before and after blending with HPMC did not indicate any difference in degree of cross-linking between the methods, while solubility data indicated otherwise. Overall, while adding HPMC to WPI: Gly films had a large effect on the flexibility, strength, stretchability, and water solubility of the film polymeric network, results indicated that HPMC had no effect on OP through the polymer network. WPI-HPMC blend films had a desirable combination of mechanical and oxygen barrier properties, reflecting the combination of hydrogen-bonding, hydrophobic interactions, and disulfide bond cross-linking in the blended polymer network.

  11. Blended learning in health education: three case studies

    NARCIS (Netherlands)

    de Jong, N.; Savin-Baden, M.; Cunningham, A.M.; Verstegen, D.M.L.

    2014-01-01

    Blended learning in which online education is combined with face-to-face education is especially useful for (future) health care professionals who need to keep up-to-date. Blended learning can make learning more efficient, for instance by removing barriers of time and distance. In the past distance-

  12. Collaborative Inquiry: Expert Analysis of Blended Learning in Higher Education

    Science.gov (United States)

    Wold, Kari

    2013-01-01

    This paper reports on findings of a university focus group exploring blended learning in higher education. It first describes the findings regarding the amorphous definition of blended learning as well as whether and how universities might engage in the practice. This paper then explains the administrative, instructor, and student variables that…

  13. Enhancing Student Teachers' Teaching Skills through a Blended Learning Approach

    Science.gov (United States)

    Albhnsawy, Abeer Abdalhalim; Aliweh, Ahmed Mahmoud

    2016-01-01

    This study investigated the effect of a blended learning program on student teachers' teaching skills in an undergraduate microteaching course. The blended learning program lasted for nine weeks. This program aimed at integrating social network tasks and face-to-face teaching activities. Pre- and post-tests were administered to assess student…

  14. Students' Opinions on Facebook Supported Blended Learning Environment

    Science.gov (United States)

    Erdem, Mukaddes; Kibar, Pinar Nuhoglu

    2014-01-01

    The first purpose of this study was to determine students' opinions on blended learning and its implementation. The other purpose was to explore the students' opinions on Facebook integration into blended learning environment. The participants of this study were 40 undergraduate students in their fourth semester of the program.…

  15. The Effect of Blended Learning in Mathematics Course

    Science.gov (United States)

    Lin, Ya-Wen; Tseng, Chih-Lung; Chiang, Po-Jui

    2017-01-01

    With the advent of the digital age, traditional didactic teaching and online learning have been modified and gradually replaced by "Blended Learning." The purpose of this study was to explore the influences of blended learning pedagogy on junior high school student learning achievement and the students' attitudes toward mathematics. To…

  16. Blended Learning for College Students with English Reading Difficulties

    Science.gov (United States)

    Yang, Yu-Fen

    2012-01-01

    Most previous studies in blended learning simply involved on-site and online instruction without considering students' control of their own learning in these two different modalities. The purpose of this study was to investigate how college students with English reading difficulties integrate their conceptions of and approaches to blended learning…

  17. Design and Evaluation of Two Blended Learning Approaches: Lessons Learned

    Science.gov (United States)

    Cheung, Wing Sum; Hew, Khe Foon

    2011-01-01

    In this paper, we share two blended learning approaches used at the National Institute of Education in Singapore. We have been using these two approaches in the last twelve years in many courses ranging from the diploma to graduate programs. For the first blended learning approach, we integrated one asynchronous communication tool with face to…

  18. Blended Learning at the Boundary: Designing a New Internship

    Science.gov (United States)

    Heckman, Robert; Østerlund, Carsten S.; Saltz, Jeffrey

    2015-01-01

    This paper explores how blended learning can enhance learning at the boundary between academia and industry, and make possible the design of a new kind of internship. Boundary theory proposes that socio-cultural discontinuities between different environments create opportunities for learning. Blended learning pedagogy makes it possible to make the…

  19. Challenges Facing Blended Learning in Higher Education in Asia

    Science.gov (United States)

    Tham, Raymond; Tham, Lesley

    2013-01-01

    This paper examines the current stage of development of blended learning in higher education in China, South Korea and Japan, with a comparison to the city state of Singapore. It is noted that blended learning and e-learning are introduced at institutes of higher learning in these countries with varying

  20. A Rotational Blended Learning Model: Enhancement and Quality Assurance

    Science.gov (United States)

    Ghoul, Said

    2013-01-01

    Research on blended learning theory and practice is growing nowadays with a focus on the development, evaluation, and quality assurance of case studies. However, the enhancement of blended learning existing models, the specification of their online parts, and the quality assurance related specifically to them have not received enough attention.…

  1. The Challenges of Blended Learning Using a Media Annotation Tool

    Science.gov (United States)

    Douglas, Kathy A.; Lang, Josephine; Colasante, Meg

    2014-01-01

    Blended learning has been evolving as an important approach to learning and teaching in tertiary education. This approach incorporates learning in both online and face-to-face modes and promotes deep learning by incorporating the best of both approaches. An innovation in blended learning is the use of an online media annotation tool (MAT) in…

  2. Student Engagement and Blended Learning: Making the Assessment Connection

    Science.gov (United States)

    Vaughan, Norman

    2014-01-01

    There is an increased focus on student engagement and blended approaches to learning in higher education. This article demonstrates how collaborative learning applications and a blended approach to learning can be used to design and support assessment activities that increase levels of student engagement with course concepts, their peers, faculty…

  3. Shearing of particles during crack growth in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, K.G.W.; Steenbrink, A.C.; Giessen, E.V.D.

    1999-01-01

    Microstructural investigations below the fracture surface have revealed that the rubber particles in a number of polymer-rubber blends were deformed into remarkable S-like shapes. These shapes seem to have been largely ignored in previous microstructural studies of blends, but in fact cannot be expl

  4. A Blended Learning Model for Teaching Practice Course

    Science.gov (United States)

    Caner, Mustafa

    2010-01-01

    The aim of the present study is to introduce a blended learning environment and a model for pre-service teaching practice course in English Language Teacher Training Program at Anadolu University. It is supposed that providing a blended learning environment for teaching practice course would improve the practice and contribute to the professional…

  5. Engineering thermal conductivity in polymer blends

    Science.gov (United States)

    Rashidi, Vahid; Coyle, Eleanor; Kieffer, John; Pipe, Kevin

    Weak inter-chain bonding in polymers is believed to be a bottleneck for both thermal conductivity and mechanical strength. Most polymers have low thermal conductivity (~0.1 W/mK), hindering their performance in applications for which thermal management is critical (e.g., electronics packaging). In this work, we use computational methods to study how hydrogen bonding between polymer chains as well as water content can be used to engineer thermal transport in bulk polymers. We examine how changes in the number of hydrogen bonds, chain elongation, density, and vibrational density of states correlate with changes in thermal conductivity for polymer blends composed of different relative constituent fractions. We also consider the effects of bond strength, tacticity, and polymer chain mass. For certain blend fractions, we observe large increases in thermal conductivity, and we analyze these increases in terms of modifications to chain chemistry (e.g., inter-chain bonding) and chain morphology (e.g., chain alignment and radius of gyration). We observe that increasing the number of hydrogen bonds in the system results in better packing as well as better chain alignment and elongation that contribute to enhanced thermal conductivity. The Air Force Office of Scientific Research, Grant No. FA9550-14-1-0010.

  6. Thin blend films of cellulose and polyacrylonitrile

    Science.gov (United States)

    Lu, Rui; Zhang, Xin; Mao, Yimin; Briber, Robert; Wang, Howard

    Cellulose is the most abundant renewable, biocompatible and biodegradable natural polymer. Cellulose exhibits excellent chemical and mechanical stability, which makes it useful for applications such as construction, filtration, bio-scaffolding and packaging. To further expand the potential applications of cellulose materials, their alloying with synthetic polymers has been investigated. In this study, thin films of cotton linter cellulose (CLC) and polyacrylonitrile (PAN) blends with various compositions spanning the entire range from neat CLC to neat PAN were spun cast on silicon wafers from common solutions in dimethyl sulfoxide / ionic liquid mixtures. The morphologies of thin films were characterized using optical microscopy, atomic force microscopy, scanning electron microscopy and X-ray reflectivity. Morphologies of as-cast films are highly sensitive to the film preparation conditions; they vary from featureless smooth films to self-organized ordered nano-patterns to hierarchical structures spanning over multiple length scales from nanometers to tens of microns. By selectively removing the PAN-rich phase, the structures of blend films were studied to gain insights in their very high stability in hot water, acid and salt solutions.

  7. Transport through track etched polymeric blend membrane

    Indian Academy of Sciences (India)

    Kamlendra Awasthi; Vaibhav Kulshreshtha; B Tripathi; N K Acharya; M Singh; Y K Vijay

    2006-06-01

    Polymer blends of polycarbonate (PC) and polysulphone (PSF) having thickness, 27 m, are prepared by solution cast method. The transport properties of pores in a blend membrane are examined. The pores were produced in this membrane by a track etching technique. For this purpose, a thin polymer membrane was penetrated by a single heavy ion of Ni7+ of 100 MeV, followed by preferential chemical etching of the ion track. Ion permeation measurements show that pores in polymeric membrane are charged or neutralized, which depends upon the variation in concentration of the solvent. The – curve at concentration, N/10, shows that the pores are negatively charged, whereas at concentration, N/20, the linear nature of – curve indicates that the pores approach towards neutralized state and on further concentration, N/40, the pores become fully neutralized, consequently the rectifier behaviour of pores has been omitted. The gas permeability of hydrogen and carbon dioxide of this membrane was measured with increasing etching time. The permeability was measured from both the sides. Permeability at the front was larger than the permeability at the back which shows asymmetric behaviour of membranes.

  8. Blending Online Asynchronous and Synchronous Learning

    Directory of Open Access Journals (Sweden)

    Lisa C. Yamagata-Lynch

    2014-04-01

    Full Text Available In this article I will share a qualitative self-study about a 15-week blended 100% online graduate level course facilitated through synchronous meetings on Blackboard Collaborate and asynchronous discussions on Blackboard. I taught the course at the University of Tennessee (UT during the spring 2012 semester and the course topic was online learning environments. The primary research question of this study was: How can the designer/instructor optimize learning experiences for students who are studying about online learning environments in a blended online course relying on both synchronous and asynchronous technologies? I relied on student reflections of course activities during the beginning, middle, and the end of the semester as the primary data source to obtain their insights regarding course experiences. Through the experiences involved in designing and teaching the course and engaging in this study I found that there is room in the instructional technology research community to address strategies for facilitating online synchronous learning that complement asynchronous learning. Synchronous online whole class meetings and well-structured small group meetings can help students feel a stronger sense of connection to their peers and instructor and stay engaged with course activities. In order to provide meaningful learning spaces in synchronous learning environments, the instructor/designer needs to balance the tension between embracing the flexibility that the online space affords to users and designing deliberate structures that will help them take advantage of the flexible space.

  9. Influence of coal blending on mineral transformation at high temperatures

    Institute of Scientific and Technical Information of China (English)

    BAI Jin; LI Wen; LI Chun-zhu; BAI Zong-qing; LI Bao-qing

    2009-01-01

    Transformation of mineral matter is important for coal utilization at high temperatures. This is especially true for blended coal. XRD and FTIR were employed together to study the transformation of mineral matter at high temperature in blended coals. It was found that the concentration of catalytic minerals, namely iron oxides, increases with an increasing ratio of Shenfu coal, which could improve coal gasification. The transformation characteristics of the minerals in blended coals are not exactly predictable from the blend ratio. This was proved by comparing the iron oxide content to the blending ratio. The results from FTIR are comparable with those from XRD. FTIR is an effective method for examining variation in mineral matter.

  10. Comprehensive characterization of chitosan/PEO/levan ternary blend films.

    Science.gov (United States)

    Bostan, Muge Sennaroglu; Mutlu, Esra Cansever; Kazak, Hande; Sinan Keskin, S; Oner, Ebru Toksoy; Eroglu, Mehmet S

    2014-02-15

    Ternary blend films of chitosan, PEO (300,000) and levan were prepared by solution casting method and their phase behavior, miscibility, thermal and mechanical properties as well as their surface energy and morphology were characterized by different techniques. FT-IR analyses of blend films indicated intermolecular hydrogen bonding between blend components. Thermal and XRD analysis showed that chitosan and levan suppressed the crystallinity of PEO up to nearly 25% of PEO content in the blend, which resulted in more amorphous film structures at higher PEO/(chitosan+levan) ratios. At more than 30% of PEO concentration, contact angle (CA) measurements showed a surface enrichment of PEO whereas at lower PEO concentrations, chitosan and levan were enriched on the surfaces leading to more amorphous and homogenous surfaces. This result was further confirmed by atomic force microscopy (AFM) images. Cell proliferation and viability assay established the high biocompatibility of the blend films.

  11. RHEOLOGICAL BEHAVIOR OF POLYPHENYLENE SULFIDE/POLYAMIDE-66 BLENDS

    Institute of Scientific and Technical Information of China (English)

    HOU Canshu; LI Jihong; WANG Yinghan; CHEN Yongrong; WANG Ling

    1996-01-01

    Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/or cross-linking in chain and Polyamide-66 (PA-66) have been prepared by melt blending. The rheological behavior of PPS/PA-66 blends has been studied by means of capillary rheometer, and compared with PPS. The effects of shear rate, shear stress and temperature on the flow of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes and the activation energies of viscous flow are obtained. The results show that the apparent viscosity of PPS/PA-66 blends is not sensitive to shear rate and stress, but decreases with the elevation of temperature. On the contrary, the apparent viscosity of the PPS decreases obviously with the increasing of shear rate and shear stress, but it is increased by the elevation of temperatue.

  12. Mechanical durability and combustion characteristics of pellets from biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Gil, M.V.; Oulego, P.; Casal, M.D.; Pevida, C.; Pis, J.J.; Rubiera, F. [CSIC, Oviedo (Spain)

    2010-11-15

    Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10-30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (<20%) with chestnut and pine sawdusts did not decrease pellet durability. The biomass/biomass blends presented combustion profiles similar to those of the individual raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends.

  13. Blended Learning in Vocational Education: Teachers' Conceptions of Blended Learning and Their Approaches to Teaching and Design

    Science.gov (United States)

    Bliuc, Ana-Maria; Casey, Grant; Bachfischer, Agnieszka; Goodyear, Peter; Ellis, Robert A.

    2012-01-01

    This paper presents research exploring teachers' experiences of using blended learning in vocational education. Teachers involved in designing and teaching using blended learning from a major Australian vocational education provider participated in the study. They received open-ended questionnaires asking to describe their conceptions of blended…

  14. The Literature Landscape of Blended Learning in Higher Education: The Need for Better Understanding of Academic Blended Practice

    Science.gov (United States)

    Torrisi-Steele, Geraldine; Drew, Steve

    2013-01-01

    If we are to realise the potential of blended learning in higher education, then further research into academic practice and relevant academic development is essential. Our review of literature on blended learning in higher education reveals an interesting scholarship landscape which, when described in detail, pointedly directs attention to the…

  15. Transactional distance in a blended learning environment

    Directory of Open Access Journals (Sweden)

    Jon Dron

    2004-12-01

    Full Text Available This paper presents a case study that describes and discusses the problems encountered during the design and implementation of a blended learning course, largely taught online through a web-based learning environment. Based on Moore's theory of transactional distance, the course was explicitly designed to have dialogue at its heart. However, the reality of systemic behaviours caused by delivering such a course within a group of conventional further and higher educational institutions has led to an entirely unanticipated reversion to structure, with unpleasant consequences for both quality and quantity of dialogue. The paper looks at some of the reasons for this drift, and suggests that some of the disappointing results (in particular in terms of the quality of the students' experience and associated poor retention can be attributed to the lack of dialogue, and consequent increase in transactional distance. It concludes with a description and evaluation of steps currently being taken to correct this behaviour.

  16. Quantum and gravity. Blend or melange?

    Energy Technology Data Exchange (ETDEWEB)

    Wuethrich, Christian [University of Geneva (Switzerland)

    2016-07-01

    Do we need to quantize gravity, as it is tacitly assumed in much of fundamental physics? The standard lore falls short of justifying an affirmative answer. Black hole thermodynamics is widely considered, faint though it may be, our firmest hint at a quantum theory of gravity - despite the failure to date to observe Hawking radiation or any other effect that would require going beyond a classical description of black holes. Hawking radiation hitherto merely enjoys a theoretical derivation in a semi-classical theory combining quantum matter with classical gravity. But how can a semi-classical melange of physical principles possibly justify that the quantum and gravity are blended into a unified fundamental theory when the latter is generally expected to reject at least some of the principles in the former?.

  17. INOVASI PEMBELAJARAN AKUNTANSI BERBASIS BLENDED LEARNING

    Directory of Open Access Journals (Sweden)

    Lyna Latifah

    2016-02-01

    Full Text Available the accounting lectures have a big challengeb to improve the quality of graduates who are expected to have high knowledge and skill, to have good critical analysis and decision making. Thus: accounting lecturers are needed to improve their teaching and learning processes especially on learning design and assessment. Improving students knowledge and skill in accounting field can be created by using learning philosophy which makes students active and integrative in the class room. this articles discusses about the innovation of accounting learning with blended learning which collaborates cooperative learning and e-learning. Cooperative learning is a learning approach which emphasizes on structured behavior to cooperate in groups it can improve students interpersonal skill, cooperation, critical analysis and decision making. On the other hand, the application of cooperative learning needs more time so it can be solved by using computer with e-learning.

  18. Comparison of Hybrid Blends for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Maria C. Lechmann

    2010-03-01

    Full Text Available In blended hybrid systems distinct micro- or nanostructured materials can be formed by phase separation. Network structures of particles or rods in a polymer matrix can be developed via self-assembly. We use this blending approach to compare active materials for application in solar cell devices. Blends were fabricated from either poly(hexylthiophene P3HT or poly(triphenylamine PTPA mixed with nanocrystalline TiO2 rods. In this manner, we compare two different hole conducting polymers in their performance in photovoltaic devices, while experimental conditions are kept identical. We find that the choice of solvent and photovoltaic characterization conducted in inert atmosphere is of importance for blends prepared from P3HT/TiO2 blends, but not for PTPA/TiO2 blends. Even though prepared with the same TiO2 rods, solar cells prepared from PTPA blends showed an enhanced efficiency when measured under ambient conditions. Furthermore, the PTPA/TiO2 showed higher long-term stability.

  19. Improved Mechanical Properties of Compatibilized Polypropylene/Polyamide-12 Blends

    Directory of Open Access Journals (Sweden)

    Nora Aranburu

    2015-01-01

    Full Text Available Compatibilized blends of polypropylene (PP and polyamide-12 (PA12 as a second component were obtained by direct injection molding having first added 20% maleic anhydride-modified copolymer (PP-g-MA to the PP, which produced partially grafted PP (gPP. A nucleating effect of the PA12 took place on the cooling crystallization of the gPP, and a second crystallization peak of the gPP appeared in the PA12-rich blends, indicating changes in the crystalline morphology. There was a slight drop in the PA12 crystallinity of the compatible blends, whereas the crystallinity of the gPP increased significantly in the PA12-rich blends. The overall reduction in the dispersed phase particle size together with the clear increase in ductility when gPP was used instead of PP proved that compatibilization occurred. Young’s modulus of the blends showed synergistic behavior. This is proposed to be both due to a change in the crystalline morphology of the blends on the one hand and, on the other, in the PA12-rich blends, to the clear increase in the crystallinity of the gPP phase, which may, in turn, have been responsible for the increase in its continuity and its contribution to the modulus.

  20. Quantification of rice bran oil in oil blends

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, R.; Sharma, H. K.; Sengar, G.

    2012-11-01

    Blends consisting of physically refined rice bran oil (PRBO): sunflower oil (SnF) and PRBO: safflower oil (SAF) in different proportions were analyzed for various physicochemical parameters. The quantification of pure rice bran oil in the blended oils was carried out using different methods including gas chromatographic, HPLC, ultrasonic velocity and methods based on physico-chemical parameters. The physicochemical parameters such as ultrasonic velocity, relative association and acoustic impedance at 2 MHz, iodine value, palmitic acid content and oryzanol content reflected significant changes with increased proportions of PRBO in the blended oils. These parameters were selected as dependent parameters and % PRBO proportion was selected as independent parameters. The study revealed that regression equations based on the oryzanol content, palmitic acid composition, ultrasonic velocity, relative association, acoustic impedance, and iodine value can be used for the quantification of rice bran oil in blended oils. The rice bran oil can easily be quantified in the blended oils based on the oryzanol content by HPLC even at a 1% level. The palmitic acid content in blended oils can also be used as an indicator to quantify rice bran oil at or above the 20% level in blended oils whereas the method based on ultrasonic velocity, acoustic impedance and relative association showed initial promise in the quantification of rice bran oil. (Author) 23 refs.

  1. CURING AND MECHANICAL PROPERTIES OF CHLOROSULPHONATED POLYETHYLENE RUBBER BLEND

    Directory of Open Access Journals (Sweden)

    Jaroslava Budinski-Simendić

    2011-09-01

    Full Text Available In this paper, the curing and mechanical properties of two series of prepared blends, i.e., chlorosulphonated polyethylene (CSM/isobutylene-co-isoprene (IIR rubber blends and chlorosulphonated polyethylene (CSM/chlorinated isobutylene-co-isoprene (CIIR rubber blends were carried out. Blends were prepared using a two-roll mill at a temperature of 40-50 °C. The curing was assessed using a Monsanto oscillating disc rheometer R-100. The process of vulcanization accelerated sulfur of pure rubbers and their blends was carried out in an electrically heated laboratory hydraulic press under a pressure of about 4 MPa and 160 °C. The stress-strain experiments were performed using a tensile tester machine (Zwick 1425. Results indicate that the scorch time, ts2, and optimum cure time, tc90, increase with increasing CSM content in both blends. The value of modulus at 100 and 300% elongation and tensile strength increases with increasing CSM content, whereas elongation at break shows a decreasing trend. The enhancement in mechanical properties was supported by data of crosslink density in these samples obtained from swelling measurement and scanning electron microscopy studies of the rubber blends fractured surfaces

  2. Blended learning in health education: three case studies.

    Science.gov (United States)

    de Jong, Nynke; Savin-Baden, Maggi; Cunningham, Anne Marie; Verstegen, Daniëlle M L

    2014-09-01

    Blended learning in which online education is combined with face-to-face education is especially useful for (future) health care professionals who need to keep up-to-date. Blended learning can make learning more efficient, for instance by removing barriers of time and distance. In the past distance-based learning activities have often been associated with traditional delivery-based methods, individual learning and limited contact. The central question in this paper is: can blended learning be active and collaborative? Three cases of blended, active and collaborative learning are presented. In case 1 a virtual classroom is used to realize online problem-based learning (PBL). In case 2 PBL cases are presented in Second Life, a 3D immersive virtual world. In case 3 discussion forums, blogs and wikis were used. In all cases face-to-face meetings were also organized. Evaluation results of the three cases clearly show that active, collaborative learning at a distance is possible. Blended learning enables the use of novel instructional methods and student-centred education. The three cases employ different educational methods, thus illustrating diverse possibilities and a variety of learning activities in blended learning. Interaction and communication rules, the role of the teacher, careful selection of collaboration tools and technical preparation should be considered when designing and implementing blended learning.

  3. Comparison of hybrid blends for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Lechmann, M. C.; Gutmann, J. S. [Max Planck Institute for Polymer Research, Mainz (Germany); Institute for Physical Chemistry, Johannes Gutenberg University, Mainz (Germany); Koll, D.; Tremel, W. [Institute for Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany); Kessler, D. [Institute for Organic Chemistry, Johannes Gutenberg University, Mainz (Germany); Theato, P. [Institute for Organic Chemistry, Johannes Gutenberg University, Mainz (Germany); School of Chemical and Biological Engineering, WCU program of Chemical Convergence for Energy and Environment (C2E2), College of Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of)

    2010-07-01

    In blended hybrid systems distinct micro- or nanostructured materials can be formed by phase separation. Network structures of particles or rods in a polymer matrix can be developed via self-assembly. We use this blending approach to compare active materials for application in solar cell devices. Blends were fabricated from either poly(hexylthiophene) P3HT or poly(triphenylamine) PTPA mixed with nanocrystalline TiO{sub 2} rods. In this manner, we compare two different hole conducting polymers in their performance in photovoltaic devices, while experimental conditions are kept identical. We find that the choice of solvent and photovoltaic characterization conducted in inert atmosphere is of importance for blends prepared from P3HT/TiO{sub 2} blends, but not for PTPA/TiO{sub 2} blends. Even though prepared with the same TiO{sub 2} rods, solar cells prepared from PTPA blends showed an enhanced efficiency when measured under ambient conditions. Furthermore, the PTPA/TiO{sub 2} showed higher long-term stability. (author)

  4. Blended learning in ethics education: a survey of nursing students.

    Science.gov (United States)

    Hsu, Li-Ling

    2011-05-01

    Nurses are experiencing new ethical issues as a result of global developments and changes in health care. With health care becoming increasingly sophisticated, and countries facing challenges of graying population, ethical issues involved in health care are bound to expand in quantity and in depth. Blended learning rather as a combination of multiple delivery media designed to promote meaningful learning. Specifically, this study was focused on two questions: (1) the students' satisfaction and attitudes as members of a scenario-based learning process in a blended learning environment; (2) the relationship between students' satisfaction ratings of nursing ethics course and their attitudes in the blended learning environment. In total, 99 senior undergraduate nursing students currently studying at a public nursing college in Taiwan were invited to participate in this study. A cross-sectional survey design was adopted in this study. The participants were asked to fill out two Likert-scale questionnaire surveys: CAAS (Case Analysis Attitude Scale), and BLSS (Blended Learning Satisfaction Scale). The results showed what students felt about their blended learning experiences - mostly items ranged from 3.27-3.76 (the highest score is 5). Another self-assessment of scenario analysis instrument revealed the mean scores ranged from 2.87-4.19. Nearly 57.8% of the participants rated the course 'extremely helpful' or 'very helpful.' This study showed statistically significant correlations (r=0.43) between students' satisfaction with blended learning and case analysis attitudes. In addition, results testified to a potential of the blended learning model proposed in this study to bridge the gap between students and instructors and the one between students and their peers, which are typical of blended learning, and to create meaningful learning by employing blended pedagogical consideration in the course design. The use of scenario instruction enables students to develop critical

  5. Analytical Characterization of Pure and Blended Watermelon (Citrullus lanatus oil: Impact of Blending on Oxidative Stability

    Directory of Open Access Journals (Sweden)

    Muhammad Waqar Azeem

    2015-06-01

    Full Text Available Analytical characterization of pure, blended watermelon (Citrulluslanatus oil and impact of blending on oxidative stability was investigated. Watermelon oil was added with mango (Mangiferaindica L. kernel oil at four different concentrations 5, 10, 15 and 20% (B1, B2, B3 and B4 and referenced with a control (100% watermelon oil. All the blends were stored in transparent PET bottles at ambient temperature (25-28oC for 3 months; storage stability was assessed at the interval of 1 month. Free fatty acid, unsaponifiable matter, saponification value, refractive index and iodine value of watermelon seed oil and mango kernel oil was 1.38%, 0.34%; 0.71%, 1.68%; 198, 193; 1.468, 1.457; 107.51, 54.62, respectively. The α tocopherol content of watermelon oil, mango kernel oil, B1, B2, B3 and B4 was 127.49, 205.44, 135.24, 144.52, 156.81 and 169.34 mg/kg. δ tocopherol in watermelon oil, mango kernel oil, B1, B2, B3 and B4 was 55.26, 34.81, 53.64, 51.27, 50.14 and 48.23 mg/kg. Concentration of linoleic acid decreased from 50.78% to 30.17% when 40% mango kernel oil was added to watermelon oil. Oleic acid increased from 22.89% in watermelon oil to 25.19%, 28.84% and 30.64% in B1, B2, B3 and B4. The increase in peroxide value of watermelon oil, B1, B2, B3 and B4 was 10.07, 9.56, 7.62, 5.17 and 2.87 (meqO2/kg in a time dependent manner. Induction period of pure watermelon oil was less than mango kernel oil and blends. These results suggest that chemical characteristics and oxidative stability of pure watermelon oil can be improved by blending with mango kernel oil.

  6. A rheological study of behavior of polymer-bitumen blends

    Energy Technology Data Exchange (ETDEWEB)

    Djonlagic, J. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy; Dunjic, B. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy; Javanovic, J.A. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy

    1996-12-01

    The influence of the elastomer such as SBS and SBR and their mixtures on the structure and rheological properties of blown bitumen B 65 blends, was studied. The crude oil denoted as SEB (Soviet Export Blend) was used to obtain the B 65 sample. (orig./HS) [Deutsch] Es wurde die Wirkung der SBR- und SBS-Elastomere und ihrer Mischungen, auf die Struktur und die rheologischen Eigenschaften des aus geblasenem Bitumen B 65 hergestellten Polymer-Bitumens (PmB), untersucht. Die B 65 Probe stammte aus dem Erdoel SEB (Soviet Export Blend). (orig./HS)

  7. Exciton and Hole-Transfer Dynamics in Polymer: Fullerene Blends

    Directory of Open Access Journals (Sweden)

    van Loosdrecht P. H. M.

    2013-03-01

    Full Text Available Ultrafast hole transfer dynamics from fullerene derivative to polymer in bulk heterojunction blends are studied with visible-pump - IR-probe spectroscopy. The hole transfer process is found to occur in 50/300 fs next to the interface, while a longer 15-ps time is attributed to exciton diffusion towards interface in PC71BM domains. High polaron generation efficiency in P3HT blends indicates excellent intercalation between the polymer and the fullerene even at highest PC71BM concentration thereby yielding a valuable information on the blend morphology.

  8. Compatibilized blends and value added products from leather industry waste

    Science.gov (United States)

    Sartore, Luciana; Di Landro, Luca

    2014-05-01

    Blends based on poly(ethylene-co-vinyl acetate) (EVA) and hydrolyzed proteins (IP), derived from waste products of the leather industry, have been obtained by reactive blending and their chemical physical properties as well as mechanical and rheological behavior were evaluated. The effect of vinyl acetate content and of transesterification agent addition to increase interaction between polymer and bio-based components were considered. These blends represent a new type of biodegradable material and resulted promising for industrial application in several fields such as packaging and agriculture as transplanting or mulching films with additional fertilizing action of IP.

  9. A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Blended cement containing blast furnace slag(BFS) and phosphorous slag(PS) is a new kind of cement.The total content of blended materials could increase if two additives were used. Using the same admixtures, the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB.The strength of cement with 80% additives could reach the standard of 425-grade slag cement.The tests of strength, pore structure,hydration products,inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

  10. CROSSLINKING AND COMPATIBILIZATION IN BLENDS OF POLYSTYRENE AND POLYETHYLENE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    This paper investigated the influences ofbutadiene rubber (BR) and dicumyl peroxide (DCP) on thermal and rheological behaviour, morphology and mechanical properties of PS/LLDPE/SBS blend. Addition of DCP alone was found to decrease the mechanical properties of PS/LLDPE/SBS blend due to the decomposition of PS. When BR was added together with DCP, it is found that the co-crosslinking of BR, SBS and PE takes place,and the decomposition of PS is reduced simultaneously because of the consumption of the free radicals in the crosslinking process. Synergism was thus realised which resulted in the improvement of the ductility of blend.

  11. Phase equilibria in polymer blend thin films: a Hamiltonian approach.

    Science.gov (United States)

    Souche, M; Clarke, N

    2009-12-28

    We propose a Hamiltonian formulation of the Flory-Huggins-de Gennes theory describing a polymer blend thin film. We then focus on the case of 50:50 polymer blends confined between antisymmetric walls. The different phases of the system and the transitions between them, including finite-size effects, are systematically studied through their relation with the geometry of the Hamiltonian flow in phase space. This method provides an easy and efficient way, with strong graphical insight, to infer the qualitative physical behavior of polymer blend thin films.

  12. Controlling the Solidification of Organic Photovoltaic Blends with Nucleating Agents

    KAUST Repository

    Nekuda Malik, Jennifer A.

    2014-11-20

    Blending fullerenes with a donor polymer for the fabrication of organic solar cells often leads to at least partial vitrification of one, if not both, components. For prototypical poly(3-hexylthiophene):fullerene blend, we show that the addition of a commercial nucleating agent, di(3,4-dimethyl benzylidene)sorbitol, to such binary blends accelerates the crystallization of the donor, resulting in an increase in its degree of crystallinity in as-cast structures. This allows manipulation of the extent of intermixing/ phase separation of the donor and acceptor directly from solution, offering a tool to improve device characteristics such as power conversion efficiency.

  13. Improved water solubility of neohesperidin dihydrochalcone in sweetener blends.

    Science.gov (United States)

    Benavente-García, O; Castillo, J; Del Baño, M J; Lorente, J

    2001-01-01

    Significant technological advantages in terms of sweetness synergy and hence cost-saving can be obtained if neohesperidin dihydrochalcone (NHDC) is used in sweetener blends with other intense or bulk sweeteners. The combination of NHDC with sodium saccharin or sodium cyclamate is an excellent method to improve the water solubility at room temperature of NHDC. In the case of NHDC-sodium saccharin, two different methods for blend preparation, a simple mixture and a cosolubilized mixture, can be used, with similar results obtained for solubility and solution stability properties. To improve temporally the water solubility of NHDC in combination with sodium cyclamate, it is absolutely necessary to prepare cosolubilized blends.

  14. Image blending techniques and their application in underwater mosaicing

    CERN Document Server

    Prados, Ricard; Neumann, László

    2014-01-01

    This work proposes strategies and solutions to tackle the problem of building photo-mosaics of very large underwater optical surveys, presenting contributions to the image preprocessing, enhancing and blending steps, and resulting in an improved visual quality of the final photo-mosaic. The text opens with a comprehensive review of mosaicing and blending techniques, before proposing an approach for large scale underwater image mosaicing and blending. In the image preprocessing step, a depth dependent illumination compensation function is used to solve the non-uniform illumination appearance du

  15. Electrospun fiber and cast films produced using zein blends with nylon-6

    Science.gov (United States)

    Blends of zein and nylon-6 (55k) were used to produce electrospun fibers and solution cast films. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measureme...

  16. Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends

    Energy Technology Data Exchange (ETDEWEB)

    2016-03-01

    This document provides information on ethanol fuel properties, standards, codes, best practices, and equipment information for those who blend, distribute, store, sell, or use E15 (gasoline blended with 10.5 percent - 15 percent ethanol), E85 (marketing term for ethanol-gasoline blends containing 51 percent - 83 percent ethanol, depending on geography and season), and other ethanol blends.

  17. Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-03-02

    This document provides information on ethanol fuel properties, standards, codes, best practices, and equipment information for those who blend, distribute, store, sell, or use E15 (gasoline blended with 10.5 percent - 15 percent ethanol), E85 (marketing term for ethanol-gasoline blends containing 51 percent - 83 percent ethanol, depending on geography and season), and other ethanol blends.

  18. Effects of blended-cement paste chemical composition changes on some strength gains of blended-mortars.

    Science.gov (United States)

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement.

  19. Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

    Directory of Open Access Journals (Sweden)

    Mehmet Serkan Kirgiz

    2014-01-01

    Full Text Available Effects of chemical compositions changes of blended-cement pastes (BCPCCC on some strength gains of blended cement mortars (BCMSG were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP or 6%, 20%, 21%, and 35% brick powder (BP for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min. Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS and flexural strengths (FS of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2, sodium oxide (Na2O, and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2 at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM in comparison with reference mortars (RM at whole cure days as MP up to 6% or BP up to 35% was blended for cement.

  20. Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

    Science.gov (United States)

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement. PMID:24587737

  1. Pluronic F127/chitosan blend microspheres for mucoadhesive drug delivery

    Science.gov (United States)

    Gu, W. Z.; Hu, X. F.

    2017-01-01

    Pluronic F127/chitosan blend microspheres were prepared via emulsification and cross-linking process using glutaraldehyde as a cross-linker. Compared with chitosan microspheres fabricated under the same experimental conditions, blend microspheres exhibited better physical stability and higher swelling capacity. Puerarin, a traditional Chinese medicine, was incorporated into microparticlesas the model drug. The in vitro release of puerarin from blend microspheres was reduced because of the improved compatibility of the drug with the matrices. According to the results from in vitro adhesion experiments, mucoadhesive behavior of blend microspheres on a mucosa-like surface was similar to that of chitosan microspheres, despite their good ability of anti-protein absorption in solution.

  2. Characterization of Fibers Produced from Blends of Polybutylene and Polypropylene

    Directory of Open Access Journals (Sweden)

    Robert L. Shambaugh, Ph.D

    2007-11-01

    Full Text Available Blends of polybutylene (PB-1 and polypropylene were used to produce fibers at spinning speeds of 800-2100 m/min. Concentrations ranged from 0% PP to 100% PP. The stress-strain behavior of the resultant fibers was examined, and the fibers were analyzed for crystallinity via DSC (differential scanning calorimetry. Fibers produced from blends of PB-1/PP show mechanical properties that are in between the properties of the pure polymers. The tensile strength of 50% PB-1 fibers is comparable to the tensile strength of pure PP fibers. Fibers produced from blend compositions of 25 and 75% have higher tensile strengths than pure PP fibers, although these blend compositions have lower tensile strengths than pure PB fibers.

  3. Phase Behavior of Polymer Blends for Organic Photovoltaic Applications

    Science.gov (United States)

    Emerson, Jillian; Furst, Eric; Epps, Thomas, III

    2014-03-01

    Polymer blends offer a promising and economically-viable route to creating organic photovoltaic (OPV) devices, as blends can form bicontinuous domains via spinodal decomposition. Understanding the phase behavior of conjugated polymer blends commonly used in OPVs is vital to producing more efficient devices. In this work, we determined the Flory-Huggins solvent-polymer and polymer-polymer interaction parameters for a model system of poly(3-hexylthiophene) (P3HT) and polystyrene (PS) through solvent vapor swelling of thin polymer films. From these interaction parameters, we constructed a polymer/polymer/solvent phase diagram. The phase diagram was validated experimentally with solution-based transmission measurements of PS/P3HT. This work highlights a method to determine the phase behavior in polymer/polymer/solvent blends that can be extended to other combinations of macromolecules relevant to organic photovoltaics, composites, and other materials systems.

  4. Tensile deformation mechanisms of ABS/PMMA/EMA blends

    Science.gov (United States)

    Wang, S. H.; Gao, J.; Lin, S. X.; Zhang, P.; Huang, J.; Xu, L. L.

    2014-08-01

    The tensile deformation mechanisms of acrylonitrile - butadiene - styrene (ABS) / polymethyl methacrylate (PMMA) blends toughened by ethylene methacrylate (EMA) copolymer was investigated by analysing the fracture morphology. ABS/PMMA was blended with EMA copolymer by melt mixing technique using co-rotating twin extruder. Tensile tests show that the elongation at break of ABS/PMMA blends can be efficiently improved with the increase in EMA content. Fracture morphology of ABS/PMMA/EMA blends reveals that the material yield induced by hollowing-out of EMA particles and its propagation into yield zone is the main toughening mechanism. Moreover, the appearance that EMA particles in the central area are given priority to hollowing-out may be related to the skin-core structure of the injection moulded parts caused by the different cooling rate between surface and inside in the process of injection moulding.

  5. Perception of blended learning inventory (POBLI) - development and validation

    DEFF Research Database (Denmark)

    Lassesen, Berit; Rossen, Dorte Sidelmann; Stenalt, Maria Hvid

    and explore how the use of blended learning affects teachers’ approaches to teaching and students’ approaches to learning in higher education. So far, there has been relatively limited research on approaches to teaching in blended learning (González 2010; Lameras et al., 2012). In one study, Ellis et al....... (2006) found that an unclear, fragmented conception of the use of blended teaching was associated with a teacher focused approach, whereas a more cohesive conception of blended context appeared to stimulate a more student focused approach to teaching. In another study Ginns and Ellis (2007) explored...... the relationships between students' perceptions of the e-learning environment, their approaches to studying, and their academic performance. The results indicated that students differed widely in their perception of the environment, resulting in variations in study approaches and grades. It is well...

  6. Composition fluctuations in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Mortensen, K.; Almdal, K.

    2000-01-01

    The thermal composition fluctuations of a deuterogenous polystyrene/polyethyleneoxide (dPS/PEO) homopolymer blend and corresponding diblock copolymer have been investigated by small angle neutron scattering (SANS). The measured susceptibilities could be described by theories, which take strong...

  7. Influence of compatibilizer on blends degradation during processing

    Directory of Open Access Journals (Sweden)

    Walter R. Waldman

    2013-01-01

    Full Text Available The thermomechanical degradation of blends made from polypropylene and polystyrene, with or without compatibilizer, was studied using an internal mixer coupled to a torque rheometer. The blends processed without compatibilizer presented regular and expected results regarding torque reduction, with evidence of chain scission. The blends processed with the block copolymer of styrene and butadiene, SBS, as a compatibilizer presented unchanged or less reduced variation on torque values during processing. The extraction of stabilizers from the compatibilizer before processing did not affect the results. The compatibilizer concentration in the blends was varied, with its influence still being observed in concentrations as low as 0.03 parts per hundred. Similar results were obtained in an experiment comparing the performance of a primary commercial anti-oxidant, Irganox 1076, and the compatibilizer SBS. Therefore, the compatibilizer can be considered as a processing aid agent with positive influence on avoiding thermomechanical degradation.

  8. Development of rice bran oil blends for quality improvement.

    Science.gov (United States)

    Choudhary, Monika; Grover, Kiran; Kaur, Gurpreet

    2015-04-15

    Six rice bran oil (RBO) blends were prepared in two ratios i.e., 80:20 and 70:30 and analysed for physicochemical properties, and antioxidants and fatty acid composition. Among all the RBO blends, rice bran oil+groundnut oil (70:30) had the highest smoke point (204 °C) and rice bran oil+olive oil (70:30) was the most stable blend in terms of chemical parameters. The highest value of total antioxidants was observed in rice bran oil+sunflower oil (70:30) (2568.7 mg/kg). Fatty acid composition (SFA:MUFA:PUFA) (1:1.5:2) of rice bran oil+palm oil (80:20), and products prepared using this RBO blend, were close to the recommended intake. Boiling with sautéing was a better cooking method in terms of maintaining fatty acid ratios.

  9. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    Directory of Open Access Journals (Sweden)

    Hasmukh S. Patel

    2004-01-01

    Full Text Available Novel unsaturated poly (ester-amide resins (UPEAs were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY. to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO as a catalyst and was monitored by using a differential scanning calorimeter (DSC. The glass fibre reinforced composites (i.e. laminates of these UPEA-STY. resin blends were fabricated using the DSC data. The chemical, mechanical and electrical properties of the glass fibre composites have also been evaluated. The unreinforced cured samples of the UPEA-STY. resin blends were also analyzed by thermogravimetry (TGA.

  10. Feedback model to support designers of blended learning courses

    NARCIS (Netherlands)

    Hummel, Hans

    2006-01-01

    Hummel, H. G. K. (2006, December). Feedback model to support designers of blended learning courses. International Review of Open and Distance Learning [Online], 7(3). Available: http://www.irrodl.org/index.php/irrodl/article/view/379/748

  11. SST, Blended, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA OceanWatch provides a blended sea surface temperature (SST) products derived from both microwave and infrared sensors carried on multiple platforms. The...

  12. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    KAUST Repository

    Zhang, Bo

    2016-08-16

    This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission of ethanol blended gasoline mixtures in future engines. The optimal fuel blend (lowest CO2 emitting fuel) is identified. A range of gasoline fuels is studied, containing different ethanol volume percentages (E0–E40), research octane numbers (RON, 92–105), and octane sensitivities (8.5–15.5). Sugarcane-based and cellulosic ethanol-blended gasolines are shown to be effective in reducing lifecycle CO2 emission, while corn-based ethanol is not as effective. A refinery simulation of production emission was utilized, and combined with vehicle fuel consumption modeling to determine the lifecycle CO2 emissions associated with ethanol-blended gasoline in turbocharged engines. The critical parameters studied, and related to blended fuel lifecycle CO2 emissions, are ethanol content, research octane number, and octane sensitivity. The lowest-emitting blended fuel had an ethanol content of 32 vol%, RON of 105, and octane sensitivity of 15.5; resulting in a CO2 reduction of 7.1%, compared to the reference gasoline fuel and engine technology. The advantage of ethanol addition is greatest on a per unit basis at low concentrations. Finally, this study shows that engine-downsizing technology can yield an additional CO2 reduction of up to 25.5% in a two-stage downsized turbocharged engine burning the optimum sugarcane-based fuel blend. The social cost savings in the USA, from the CO2 reduction, is estimated to be as much as $187 billion/year. © 2016 Elsevier Ltd

  13. Agarose and methylcellulose hydrogel blends for nerve regeneration applications

    Science.gov (United States)

    Martin, Benton C.; Minner, Eric J.; Wiseman, Sherri L.; Klank, Rebecca L.; Gilbert, Ryan J.

    2008-06-01

    Trauma sustained to the central nervous system is a debilitating problem for thousands of people worldwide. Neuronal regeneration within the central nervous system is hindered by several factors, making a multi-faceted approach necessary. Two factors contributing to injury are the irregular geometry of injured sites and the absence of tissue to hold potential nerve guides and drug therapies. Biocompatible hydrogels, injectable at room temperature, that rapidly solidify at physiological temperatures (37 °C) are beneficial materials that could hold nerve guidance channels in place and be loaded with therapeutic agents to aid wound healing. Our studies have shown that thermoreversible methylcellulose can be combined with agarose to create hydrogel blends that accommodate these properties. Three separate novel hydrogel blends were created by mixing methylcellulose with one of the three different agaroses. Gelation time tests show that the blends solidify at a faster rate than base methylcellulose at 37 °C. Rheological data showed that the elastic modulus of the hydrogel blends rapidly increases at 37 °C. Culturing experiments reveal that the morphology of dissociated dorsal root ganglion neurons was not altered when the hydrogels were placed onto the cells. The different blends were further assessed using dissolution tests, pore size evaluations using scanning electron microscopy and measuring the force required for injection. This research demonstrates that blends of agarose and methylcellulose solidify much more quickly than plain methylcellulose, while solidifying at physiological temperatures where agarose cannot. These hydrogel blends, which solidify at physiological temperatures naturally, do not require ultraviolet light or synthetic chemical cross linkers to facilitate solidification. Thus, these hydrogel blends have potential use in delivering therapeutics and holding scaffolding in place within the nervous system.

  14. Operating Systems with Blended Extreme Apprenticeship: What Are Students’ Perceptions?

    Directory of Open Access Journals (Sweden)

    Gabriella Dodero

    2015-02-01

    Full Text Available Extreme apprenticeship, an emerging learning methodology, has been used in a blended fashion for teaching a technical subject: bash scripting for operating systems. Online learning was first supported with the Moodle platform, and then enhanced with playful videos. How did students perceive learning in such a manner? This paper reports on the design of the blended learning experience for operating systems, and then focusses on the evaluation of learners’ perceptions of it.

  15. Influence of Coal Blending on Ash Fusibility in Reducing Atmosphere

    Directory of Open Access Journals (Sweden)

    Mingke Shen

    2015-05-01

    Full Text Available Coal blending is an effective way to organize and control coal ash fusibility to meet different requirements of Coal-fired power plants. This study investigates three different eutectic processes and explains the mechanism of how coal blending affects ash fusibility. The blended ashes were prepared by hand-mixing two raw coal ashes at five blending ratios, G:D = 10:90 (G10D90, G:D= 20:80 (G20D80, G:D = 30:70 (G30D70, G:D = 40:60 (G40D60, and G:D = 50:50 (G50D50. The samples were heated at 900 °C, 1000 °C, 1100 °C, 1200 °C, and 1300 °C in reducing atmosphere. XRD and SEM/EDX were used to identify mineral transformations and eutectic processes. The eutectic processes were finally simulated with FactSage. Results show that the fusion temperatures of the blended ashes initially decrease and then increase with the blending ratio, a trend that is typical of eutectic melting. Eutectic phenomena are observed in D100, G10D90, and G30D70 in different degrees, which do not appear in G100 and G50D50 for the lack of eutectic reactants. The main eutectic reactants are gehlenite, magnetite, merwinite, and diopside. The FactSage simulation results show that the content discrepancy of merwinite and diopside in the ashes causes the inconsistent eutectic temperatures and eutectic degrees, in turn decrease the fusion temperature of the blended ash and then increase them with the blending ratio.

  16. Becoming Blended. A Case Study in Teacher Identity

    OpenAIRE

    Rentería, Victoria

    2014-01-01

    This case-study explores the identities of two teachers in the English Blended Program of a Mexican University during a four month period. The aim is to discover how agency creates different kinds of impacts on teacher's identity in the context of a blended program. Through an interpretive and sociocultural perspective an analysis was conducted by examining data gathered from face-to-face class observations, teacher's Moodle pages, teacher's journals and interviews, as well as questionnaires ...

  17. Novel bio-based and biodegradable polymer blends

    Science.gov (United States)

    Yang, Shengzhe

    Most plastic materials, including high performance thermoplastics and thermosets are produced entirely from petroleum-based products. The volatility of the natural oil markets and the increasing cost of petroleum have led to a push to reduce the dependence on petroleum products. Together with an increase in environmental awareness, this has promoted the use of alternative, biorenewable, environmentally-friendly products, such as biomass. The growing interest in replacing petroleum-based products by inexpensive, renewable, natural materials is important for sustainable development into the future and will have a significant impact on the polymer industry and the environment. This thesis involved characterization and development of two series of novel bio-based polymer blends, namely polyhydroxyalkanoate (PHA)/polyamide (PA) and poly(lactic acid) (PLA)/soy protein. Blends with different concentrations and compatible microstructures were prepared using twin-screw extruder. For PHA/PA blends, the poor mechanical properties of PHA improved significantly with an excellent combination of strength, stiffness and toughness by adding PA. Furthermore, the effect of blending on the viscoelastic properties has been investigated using small-amplitude oscillatory shear flow experiments as a function of blend composition and angular frequency. The elastic shear modulus (G‧) and complex viscosity of the blends increased significantly with increasing the concentration of PHA. Blending PLA with soy protein aims at reducing production cost, as well as accelerating the biodegradation rate in soil medium. In this work, the mechanical, thermal and morphological properties of the blends were investigated using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests.

  18. AstroBlend: Visualization package for use with Blender

    Science.gov (United States)

    Naiman, J. P.

    2015-12-01

    AstroBlend is a visualization package for use in the three dimensional animation and modeling software, Blender. It reads data in via a text file or can use pre-fab isosurface files stored as OBJ or Wavefront files. AstroBlend supports a variety of codes such as FLASH (ascl:1010.082), Enzo (ascl:1010.072), and Athena (ascl:1010.014), and combines artistic 3D models with computational astrophysics datasets to create models and animations.

  19. Pro-ELT; A Teacher Training Blended Approach

    OpenAIRE

    Reza Eshtehardi

    2014-01-01

    Pro-ELT is a blended teacher training course. The aim of Pro-ELT is to strengthen English teaching and learning through a blended training approach that includes; quality face to face delivery, supported distance learning and integrated proficiency and methodology training. It delivers quality language teaching and teacher development courses to Malaysian primary and secondary school teachers working in Malaysian government schools in order to develop their English language proficiency and te...

  20. Preparation and characterization of silk fibroin/HPMC blend film

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, G. Rajesha [Department of Physics, Govt. First Grade College Hiriadka, Udupi - 576113 (India); Kumar, R. Madhu; Rao, B. Lakshmeesha; Asha, S.; Sangappa, E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore - 574199 (India)

    2015-06-24

    In this work, the structural and mechanical stability of silk fibroin/Hydroxypropylmethyl cellulose (SF-HPMC) blend films were characterized by X-ray diffraction (XRD) and Universal Testing Machine (UTM). The results indicate that with the introduction of HPMC, the interactions between SF and HPMC results in improved crystallite size and increase in mechanical properties. The blend film obtained is more flexible compared to pure SF film.

  1. Blending Worship for the 21st Century Military Force

    Science.gov (United States)

    2009-03-13

    SUBTITLE Blending Worship for the 21st Century Military Force 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jim...To) 4. TITLE AND SUBTITLE Blending Worship for the 21st Century Military Force 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...outsiders, inclusion of cultural diversity and intergenerational fellowship.43 Sam Harris saw the benefit of faith and worship and contends that we need

  2. Performance and emission characteristics of double biodiesel blends with diesel

    OpenAIRE

    Kuthalingam Arun Balasubramanian; Asokan Guruprasath; Marta Vivar; Skryabin Igor; Karuppian Srithar

    2013-01-01

    Recent research on biodiesel focused on performance of single biodiesel and its blends with diesel. The present work aims to investigate the possibilities of the application of mixtures of two biodiesel and its blends with diesel as a fuel for diesel engines. The combinations of Pongamia pinnata biodiesel, Mustard oil biodiesel along with diesel (PMD) and combinations of Cotton seed biodiesel, Pongamia pinnata biodiesel along with diesel (CPD) are taken for the experimental analysis. Ex...

  3. Blended versus lecture learning: outcomes for staff development.

    Science.gov (United States)

    Sherman, Heidi; Comer, Linda; Putnam, Lorene; Freeman, Helen

    2012-07-01

    Critical care pharmacology education is crucial to safe patient care for nurses orienting to specialized areas. Although traditionally taught as a classroom lecture, it is important to consider effectiveness of alternative methods for education. This study provided experimentally derived evidence regarding effectiveness of blended versus traditional lecture for critical care pharmacology education. Regardless of learner demographics, the findings determined no significant differences in cognitive learning outcomes or learner satisfaction between blended versus lecture formats.

  4. 有关blended learning的几个问题

    Institute of Scientific and Technical Information of China (English)

    万士全

    2005-01-01

    本文主要依据国内外的一些关于"Blended Learning"的文献资料,概括介绍一些Blended Learning的基本概念、实行策略以及媒体选择等问题,并进一步探讨其对教育教学活动的影响

  5. THE HANDBOOK OF BLENDED LEARNING:Global Perspectives, Local Designs

    OpenAIRE

    Reviewed by Alev ATES

    2009-01-01

    THE HANDBOOK OF BLENDED LEARNING:Global Perspectives, Local Designs Curtis J. Bonk (ed.) and Charles R. Graham (ed.), Jay Cross (Foreword),Micheal G. Moore Foreword) ISBN: 978-0-7879-7758-0 Publisher: John Wiley & Sons, Inc. Pfeiffer Pages: 624 March 2006.Reviewed by Alev ATESPhD Student at Curriculum and Instruction,Lecturer at Computer Education and Instructional Technologies,Faculty of Education, Ege University, Izmir, TURKEYBlended learning or blended e-learning sounds like aconfusing ter...

  6. Preparation and emission characteristics of ethanol-diesel fuel blends

    Institute of Scientific and Technical Information of China (English)

    ZHANG Run-duo; HE Hong; SHI Xiao-yan; ZHANG Chang-bin; HE Bang-quan; WANG Jian-xin

    2004-01-01

    The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.

  7. Impact of ternary blends of biodiesel on diesel engine performance

    Directory of Open Access Journals (Sweden)

    Prem Kumar

    2016-06-01

    Full Text Available The Pongamia and waste cooking oils are the main non edible oils for biodiesel production in India. The aim of the present work is to evaluate the fuel properties and investigate the impact on engine performance using Pongamia and waste cooking biodiesel and their ternary blend with diesel. The investigation of the fuel properties shows that Pongamia biodiesel and waste cooking biodiesel have poor cold flow property. This will lead to starting problem in the engine operation. To overcome this problem the ternary blends of diesel, waste cooking biodiesel and Pongamia biodiesel are prepared. The cloud and pour point for ternary blend, (WCB20:PB20:D60 were found to be 7 °C and 6.5 °C which are comparable to cloud and pour point of diesel 6 °C and 5 °C, respectively. The result of the test showed that brake specific fuel consumption for Pongamia biodiesel and waste cooking biodiesel is higher than ternary blend, (WCB20:PB20:D60 due to their lower energy content. The brake thermal efficiency of ternary blend and diesel is comparable while the Pongamia and waste cooking biodiesel have low efficiency. The result of investigation showed that ternary blend can be developed as alternate fuel.

  8. Morphology and thermal behaviour of SAN/EPDM blends

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available Blends of styrene-acrylonitrile (SAN with ethylene-propylene-diene (EPDM with and without high impact polystyrene (HIPS as a compatibilizer were studied. One series of blends was prepared in composition 95/5, 90/10, 85/15, 80/20 and 60/40; and the second series of blends was prepared with addition of 5 wt % of HIPS. Their morphology and thermal behaviour were inspected by scanning electronic microscopy (SEM and dynamic mechanic analysis (DMA, respectively. Further on, blends were separated to their components by Soxlet extraction in selective solvent and characterized by Fourier Transform Infrared Spectroscopy (FTIR and gel permeation chromatography (GPC, respectively. The results of morphological observations revealed that the addition of a small percentage of compatibilizer decreases the domain size of the dispersed phase and the compatibility of the blends was enhanced. The shifts of values of glass temperatures (Tg in the examined blends also indicate that with addition of compatibilizer HIPS miscibility between SAN and EPDM is improved.

  9. Thermal behavior and Rheological Properties of PANI-DBSMPAN Blends

    Institute of Scientific and Technical Information of China (English)

    PAN Wei

    2007-01-01

    Conducting blends of polyacrylonitrile (PAN) copolymer and dodecylbenzene sulfonic acid doped polyaniline (PANI-DBSA) were prepared by solution blending of the two components.By means of various characterization methods including differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and cone-plate rheometry,the effects of PANI-DBSA content on the thermal behavior, morphological and theological properties of the blends were investigated. A single and composition-dependent Tg was found for each of all blends and the thermal stability of PANI-DBSA/PAN was superior to that of both pure Co-PAN and PANI-DBSA. Rheological results show that the apparent viscosity of blend solution decreased at low PANI-DBSA content (2.5 wt%) while increased at high PANI-DBSA content (7.5wt%-10 wt%). Moreover, the shear-thinning appeared more distinctly with the incorporation of PANI-DBSA into the blend solutions especially at a high shear rate.

  10. Extrudability and Consolidation of Blends between CGM and DDGS

    Directory of Open Access Journals (Sweden)

    C. J. R. Verbeek

    2016-01-01

    Full Text Available During the last decade, the global biofuels industry has experienced exponential growth. By-products such as high protein corn gluten meal (CGM and high fibre distillers dried grains with solubles (DDGS have grown in parallel. CGM has been shown to be suitable as a biopolymer; the high fibre content of DDGS reduces its effectiveness, although it is considerably cheaper. In this study, the processing behaviour of CGM and DDGS blends was evaluated and resulting extrudate properties were determined. Prior to processing, urea was used as a denaturant. DDGS : CGM ratios of 0, 33, 50, 66, and 100% were processed in a single screw extruder, which solely used dissipative heating. Blends containing DDGS were less uniformly consolidated and resulted in more dissipative heating. Blends showed multiple glass transitions, which is characteristic of mechanically compatible blends. Transmission electron microscopy revealed phase separation on a microscale, although distinct CGM or DDGS phases could not be identified. On a macroscale, optical microscopy suggested that CGM-rich blends were better consolidated, supported by visual observations of a more continuous extrudate formed during extrusion. Future work should aim to also characterize the mechanical properties of these blends to assess their suitability as either bioplastic feedstock or pelletized livestock feed.

  11. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    Directory of Open Access Journals (Sweden)

    M. MARINOVIC-CINCOVIC

    2005-05-01

    Full Text Available The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40 blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microscopy (SEM. The results showed that the scorch time decreased with increasing SMR 20 CV and Pergut S 40 contents. This observation is attributed to the increasing solubility of sulfur, as the content of SMR 20 CV and Pergut S 40 in the composition increased. For temperatures greater than 140 oC, the dependence of the scorch time on blend ratios diminishes, as enough thermal energy is available to overcome the activation energy of vulcanization. The differing curing characteristics of the two blends is explained by the compatibility factor of the respective blend. Morphological analysis of the blends shows a very satisfactory agreement.

  12. Morphological studies on block copolymer modified PA 6 blends

    Science.gov (United States)

    Poindl, M.; Bonten, C.

    2014-05-01

    Recent studies show that compounding polyamide 6 (PA 6) with a PA 6 polyether block copolymers made by reaction injection molding (RIM) or continuous anionic polymerization in a reactive extrusion process (REX) result in blends with high impact strength and high stiffness compared to conventional rubber blends. In this paper, different high impact PA 6 blends were prepared using a twin screw extruder. The different impact modifiers were an ethylene propylene copolymer, a PA PA 6 polyether block copolymer made by reaction injection molding and one made by reactive extrusion. To ensure good particle matrix bonding, the ethylene propylene copolymer was grafted with maleic anhydride (EPR-g-MA). Due to the molecular structure of the two block copolymers, a coupling agent was not necessary. The block copolymers are semi-crystalline and partially cross-linked in contrast to commonly used amorphous rubbers which are usually uncured. The combination of different analysis methods like atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) gave a detailed view in the structure of the blends. Due to the partial cross-linking, the particles of the block copolymers in the blends are not spherical like the ones of ethylene propylene copolymer. The differences in molecular structure, miscibility and grafting of the impact modifiers result in different mechanical properties and different blend morphologies.

  13. FTIR characterization of protein-polysaccharide interactions in extruded blends.

    Science.gov (United States)

    Guerrero, Pedro; Kerry, Joe P; de la Caba, Koro

    2014-10-13

    Soy protein-based blends were processed by double screw extrusion and the effects of different types and contents of polysaccharides were analyzed. Although extrusion has not been widely used for this type of blends, in this study it was observed that the increase in polysaccharide content in blends caused a decrease in specific mechanical energy (SME), facilitating extrusion process and showing the potential of this process, which is more cost effective at industrial scale. In order to explain this behavior, infrared spectroscopy analysis was carried out, mainly in the amide I and II regions. Moreover, curve fitting analysis showed the conformational changes produced in the blends due to the addition of polysaccharides, which affected protein denaturation. These changes also affected properties such as moisture content (MC) and total solubility matter (TSM). However, conformational changes did not show significant effects with respect to piece density (PD) or in the expansion ratio (ER) of the pellets. The quantitative analysis of the changes in the amide I and II regions provided novel information about the modifications produced in protein-based blends modified with polysaccharides. In this context, infrared spectroscopy provided a convenient and powerful means to monitor interactions between all ingredients used in the blend formulation, which is of great importance in order to explain changes in the functional properties of biodegradable materials used for industrial applications in food and pharmaceutical industries.

  14. Silk fibroin/sodium carboxymethylcellulose blended films for biotechnological applications.

    Science.gov (United States)

    Kundu, Joydip; Mohapatra, Riti; Kundu, S C

    2011-01-01

    The potential of silk protein is increased because of its importance as natural biopolymer for biotechnological and biomedical applications. The main disadvantage of silk fibroin films is their high brittleness. Thus, we studied blends of fibroin with other polymers to improve the film properties. Considering the possible applications of films in biomedical applications, we used a natural and biodegradable polymer as the second component. This study reports the fabrication and characterization of mulberry silk protein fibroin and sodium carboxymethylcellulose (NaCMC) blended films as potential substrates for in vitro cell culture. The blended films are investigated of their chemical interactions, morphologies, thermal, mechanical properties in addition to its swelling properties and biocompatibility. The addition of NaCMC improves the elasticity of fibroin films and its thermal properties. The change of morphology, swelling behavior and increase of surface roughness of the films were also observed in the blended films. The films become insoluble on alcohol treatment and are stable for longer duration in hydrolytic medium. The blended films are cytocompatible and supported adhesion and growth of mouse fibroblast cells. The results suggest that NaCMC blended silk fibroin films are found to be potential substratum for supporting cell adhesion and proliferation.

  15. Partially Blended Constrained Rational Cubic Trigonometric Fractal Interpolation Surfaces

    Science.gov (United States)

    Chand, A. K. B.; Tyada, K. R.

    2016-08-01

    Fractal interpolation is an advance technique for visualization of scientific shaped data. In this paper, we present a new family of partially blended rational cubic trigonometric fractal interpolation surfaces (RCTFISs) with a combination of blending functions and univariate rational trigonometric fractal interpolation functions (FIFs) along the grid lines of the interpolation domain. The developed FIFs use rational trigonometric functions pi,j(θ) qi,j(θ), where pi,j(θ) and qi,j(θ) are cubic trigonometric polynomials with four shape parameters. The convergence analysis of partially blended RCTFIS with the original surface data generating function is discussed. We derive sufficient data-dependent conditions on the scaling factors and shape parameters such that the fractal grid line functions lie above the grid lines of a plane Π, and consequently the proposed partially blended RCTFIS lies above the plane Π. Positivity preserving partially blended RCTFIS is a special case of the constrained partially blended RCTFIS. Numerical examples are provided to support the proposed theoretical results.

  16. MISCIBILITY, CRYSTALLIZATION AND MECHANICAL PROPERTIES OF PPC/PBS BLENDS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, melt blends of poly(propylene carbonate) (PPC) with poly(butylene succinate) (PBS) were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), tensile testing, wide-angle X-ray diffraction (WAXD), polarized optical microscopy and thermogravimetric analysis (TGA). The results indicated that the glass transition temperature of PPC in the 90/10 PPC/PBS blend was decreased by about 11 K comparing with that of pure PPC. The presence of 10% PBS was partially miscible with PPC. The 90/10 PPC/PBS blend had better impact and tensile strength than those of the other PPC/PBS blends. The glass transition temperature of PPC in the 80/20, 70/30, and 60/40 PPC/PBS blends was improved by about 4.9 K, 4.2 K, and 13 K comparing with that of pure PPC, respectively; which indicated the immiscibility between PPC and PBS. The DSC results indicated that the crystallization of PBS became more difficult when the PPC content increased. The matrix of PPC hindered the crystallization process of PBS. While the content of PBS was above 20%, significant crystallization-induced phase separation was observed by polarized optical microscopy.It was found from the WAXD analysis that the crystal structure of PBS did not change, and the degree of crystallinity increased with increasing PBS content in the PPC/PBS blends.

  17. Chemical and Enzymatic Hydrolysis of Polyurethane/Polylactide Blends

    Directory of Open Access Journals (Sweden)

    Joanna Brzeska

    2015-01-01

    Full Text Available Polyether-esterurethanes containing synthetic poly[(R,S-3-hydroxybutyrate] (R,S-PHB and polyoxytetramethylenediol in soft segments and polyesterurethanes with poly(ε-caprolactone and poly[(R,S-3-hydroxybutyrate] were blended with poly([D,L]-lactide (PLA. The products were tested in terms of their oil and water absorption. Oil sorption tests of polyether-esterurethane revealed their higher response in comparison to polyesterurethanes. Blending of polyether-esterurethanes with PLA caused the increase of oil sorption. The highest water sorption was observed for blends of polyether-esterurethane, obtained with 10% of R,S-PHB in soft segments. The samples mass of polyurethanes and their blends were almost not changed after incubation in phosphate buffer and trypsin and lipase solutions. Nevertheless the molecular weight of polymers was significantly reduced after degradation. It was especially visible in case of incubation of samples in phosphate buffer what suggested the chemical hydrolysis of polymer chains. The changes of surface of polyurethanes and their blends, after incubation in both enzymatic solutions, indicated on enzymatic degradation, which had been started despite the lack of mass lost. Polyurethanes and their blends, contained more R,S-PHB in soft segments, were degraded faster.

  18. Morphology, thermal and mechanical properties of PVC/MMT nanocomposites prepared by solution blending and solution blending + melt compounding

    DEFF Research Database (Denmark)

    Madaleno, Liliana Andreia Oliveira; Schjødt-Thomsen, Jan; Pinto, José Cruz

    2010-01-01

    and solution blending + melt compounding The effects on morphology, thermal and mechanical properties of the PVC/MMT nanocomposites were studied by varying the amount of Na-MMT and OMMT in both methods SEM and XRD analysis revealed that possible intercalated and exfoliated structures were obtained in all...... of the PVC/MMT nanocomposites Thermogravimetric analysis revealed that PVC/Na-MMT nanocomposites have better thermal stability than PVC/OMMT nanocomposites and PVC. In general, PVC/MMT nanocomposites prepared by solution blending + melt compounding revealed improved thermal properties compared to PVC....../MMT nanocomposites prepared by solution blending Vicar tests revealed a significant decrease in Vicar softening temperature of PVC/MMT nanocomposites prepared by solution blending + melt compounding compared to unfilled PVC The mechanical properties of the PVC/MMT nanocomposites were, in general, greatly improved...

  19. A simple model to predict the biodiesel blend density as simultaneous function of blend percent and temperature.

    Science.gov (United States)

    Gaonkar, Narayan; Vaidya, R G

    2016-05-01

    A simple method to estimate the density of biodiesel blend as simultaneous function of temperature and volume percent of biodiesel is proposed. Employing the Kay's mixing rule, we developed a model and investigated theoretically the density of different vegetable oil biodiesel blends as a simultaneous function of temperature and volume percent of biodiesel. Key advantage of the proposed model is that it requires only a single set of density values of components of biodiesel blends at any two different temperatures. We notice that the density of blend linearly decreases with increase in temperature and increases with increase in volume percent of the biodiesel. The lower values of standard estimate of error (SEE = 0.0003-0.0022) and absolute average deviation (AAD = 0.03-0.15 %) obtained using the proposed model indicate the predictive capability. The predicted values found good agreement with the recent available experimental data.

  20. Polygonal Shape Blending with Topological Evolutions

    Institute of Scientific and Technical Information of China (English)

    Li-Gang Liu; Bo Zhang; Bai-Ning Guo; Heung-Yeung Shum

    2005-01-01

    This paper presents a new general approach to blend 2D shapes with different topologies. All possible topolog ical evolutions are classified into three types by attaching three different topological cells. This formalism is resulted from Morse theory on the behavior of the 3D surface around a non-degenerate critical point. Also we incorporate degenerate topological evolutions into our framework which produce more attractive morphing effects. The user controls the morph by specifying the types of topological evolutions as well as the feature correspondences between the source and target shapes.Some techniques are also provided to control the vertex path during the morphing process. The amount of user input required to produce a morph is directly proportional to the amount of control the user wishes to impose on the process.The user may allow the system to automatically generate the morph as well. Our approaches are totally geometric based and are easy and fast enough in fully interactive time. Many experimental results show the applicability and flexibility of our approaches.

  1. De‐blending reverse‐time migration

    KAUST Repository

    Fei, Tong W.

    2010-10-17

    Reverse‐time migration (RTM), based on the full two‐way wave equation, has gained interest and become a popular imaging tool for complex structures in the last few years. The method is well‐known for its ability to better image the steeply dipping and overturned structures than the migration methods based on the one‐way wave equation extrapolation. However, the RTM image often contains low frequency and back‐scattering noise, and the imaging quality is sensitive to the migration velocity. In order to improve the RTM imaging quality and make the RTM image less sensitive to the velocity model, we developed an RTM de‐blending technique which separates upgoing and downgoing source and receiver wavefields, and then use them to construct final RTM images. Test results show that decomposed images obtained from only the downgoing source and receiver wavefields are less sensitive to velocity. It removes unwanted noise and migration artifacts from conventional RTM, and the imaging quality is greatly improved compared with a conventional RTM image.

  2. Recombinant protein blends: silk beyond natural design.

    Science.gov (United States)

    Dinjaski, Nina; Kaplan, David L

    2016-06-01

    Recombinant DNA technology and new material concepts are shaping future directions in biomaterial science for the design and production of the next-generation biomaterial platforms. Aside from conventionally used synthetic polymers, numerous natural biopolymers (e.g., silk, elastin, collagen, gelatin, alginate, cellulose, keratin, chitin, polyhydroxyalkanoates) have been investigated for properties and manipulation via bioengineering. Genetic engineering provides a path to increase structural and functional complexity of these biopolymers, and thereby expand the catalog of available biomaterials beyond that which exists in nature. In addition, the integration of experimental approaches with computational modeling to analyze sequence-structure-function relationships is starting to have an impact in the field by establishing predictive frameworks for determining material properties. Herein, we review advances in recombinant DNA-mediated protein production and functionalization approaches, with a focus on hybrids or combinations of proteins; recombinant protein blends or 'recombinamers'. We highlight the potential biomedical applications of fibrous protein recombinamers, such as Silk-Elastin Like Polypeptides (SELPs) and Silk-Bacterial Collagens (SBCs). We also discuss the possibility for the rationale design of fibrous proteins to build smart, stimuli-responsive biomaterials for diverse applications. We underline current limitations with production systems for these proteins and discuss the main trends in systems/synthetic biology that may improve recombinant fibrous protein design and production.

  3. On Crystallization in Polypropylene-Polyethylene Blends

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Blends of polypropylene(PP) and low-density polyethylene (LDPE) have beencrystallized to form open structures(“cluster spherulites”) where the droplets of the minorityPP are bridged by PP lamellae which have grown in the LDPE-rich matrix. These are studiedby permanganic etching followed by electron and optical microscopies. Two similar PP typesare compared, one synthesized with Ziegler-Natta catalyst and one with metallocenecatalyst. The metallocene-catalysed material crystallized much more slowly due to thepresence of regio defects in the chains, even though the overall concentration of tacticitydefects in the Ziegler-Natta material is much higher. A mechanism involving reversal ofhelical direction at the regio defect interfering with the regular chain packing in the crystal issuggested. Growth of “cluster spherulites” is faster in regions where low molecular weightmaterial is concentrated. It is slower where droplets are larger, and this is attributed tocompetition between PP lamellar growth in the matrix and diffusion of PP to alreadycrystallized droplets.

  4. Refining and blending of aviation turbine fuels.

    Science.gov (United States)

    White, R D

    1999-02-01

    Aviation turbine fuels (jet fuels) are similar to other petroleum products that have a boiling range of approximately 300F to 550F. Kerosene and No.1 grades of fuel oil, diesel fuel, and gas turbine oil share many similar physical and chemical properties with jet fuel. The similarity among these products should allow toxicology data on one material to be extrapolated to the others. Refineries in the USA manufacture jet fuel to meet industry standard specifications. Civilian aircraft primarily use Jet A or Jet A-1 fuel as defined by ASTM D 1655. Military aircraft use JP-5 or JP-8 fuel as defined by MIL-T-5624R or MIL-T-83133D respectively. The freezing point and flash point are the principle differences between the finished fuels. Common refinery processes that produce jet fuel include distillation, caustic treatment, hydrotreating, and hydrocracking. Each of these refining processes may be the final step to produce jet fuel. Sometimes blending of two or more of these refinery process streams are needed to produce jet fuel that meets the desired specifications. Chemical additives allowed for use in jet fuel are also defined in the product specifications. In many cases, the customer rather than the refinery will put additives into the fuel to meet their specific storage or flight condition requirements.

  5. Blended learning in the small animal clinic

    DEFF Research Database (Denmark)

    Langebæk, Rikke

    2011-01-01

    At the Department of Small Animal Clinical Sciences, Basic Surgical Skills are taught in groups of 30-35 students in the first year of the master program (4th year students). The eight day course is an example of ‘blended learning’ in which students use our e-learning-material (Step 1) to prepare...... for the practical part of the course (Step 2, 3 and 4). From their home computers, students log on to the e-learning platform of Copenhagen University: https://absalon.ku.dk and go to the Basic Surgical Skills course, which consist of a line of chapters concerning a variety of surgical subjects. Each subject...... the implementation of these new teaching methods (e-learning and Skills Lab), teachers have ascertained a more satisfactory level of preparation, students that seem more focused and live-animal surgery that is conducted at a more ‘professional’ level than before. Finally, our research in this field shows...

  6. Blending Of Radioactive Salt Solutions In Million Gallon Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Leishear, Robert A.; Lee, Si Y.; Fowley, Mark D.; Poirier, Michael R.

    2012-12-10

    Research was completed at Savannah River National Laboratory (SRNL) to investigate processes related to the blending of radioactive, liquid waste, salt solutions in 4920 cubic meter, 25.9 meter diameter storage tanks. One process was the blending of large salt solution batches (up to 1135 ? 3028 cubic meters), using submerged centrifugal pumps. A second process was the disturbance of a settled layer of solids, or sludge, on the tank bottom. And a third investigated process was the settling rate of sludge solids if suspended into slurries by the blending pump. To investigate these processes, experiments, CFD models (computational fluid dynamics), and theory were applied. Experiments were performed using simulated, non-radioactive, salt solutions referred to as supernates, and a layer of settled solids referred to as sludge. Blending experiments were performed in a 2.44 meter diameter pilot scale tank, and flow rate measurements and settling tests were performed at both pilot scale and full scale. A summary of the research is presented here to demonstrate the adage that, ?One good experiment fixes a lot of good theory?. Experimental testing was required to benchmark CFD models, or the models would have been incorrectly used. In fact, CFD safety factors were established by this research to predict full-scale blending performance. CFD models were used to determine pump design requirements, predict blending times, and cut costs several million dollars by reducing the number of required blending pumps. This research contributed to DOE missions to permanently close the remaining 47 of 51 SRS waste storage tanks.

  7. Thermoset Blends of an Epoxy Resin and Polydicyclopentadiene

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, Brian J.; Le, Kim Mai; Krishnamoorti, Ramanan; Robertson, Megan L.

    2016-12-13

    The mechanical properties of two chemically distinct and complementary thermoset polymers were manipulated through development of thermoset blends. The thermoset blend system was composed of an anhydride-cured diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin, contributing high tensile strength and modulus, and polydicyclopentadiene (PDCPD), which has a higher toughness and impact strength as compared to other thermoset polymers. Ultra-small-angle and small-angle X-ray scattering analysis explored the morphology of concurrently cured thermoset blends, revealing a macroscopically phase separated system with a surface fractal structure across blended systems of varying composition. The epoxy resin rich and PDCPD rich phases exhibited distinct glass transitions (Tg’s): the Tg observed at higher temperature was associated with the epoxy resin rich phase and was largely unaffected by the presence of PDCPD, whereas the PDCPD rich phase Tg systematically decreased with increasing epoxy resin content due to inhibition of dicyclopentadiene ring-opening metathesis polymerization. The mechanical properties of these phase-separated blends were in reasonable agreement with predictions by the rule of mixtures for the blend tensile strength, modulus, and fracture toughness. Scanning electron microscopy analysis of the tensile and fracture specimen fracture surfaces showed an increase in energy dissipation mechanisms, such as crazing, shear banding, and surface roughness, as the fraction of the more ductile component, PDPCD, increased. These results present a facile method to tune the mechanical properties of a toughened thermoset network, in which the high modulus and tensile strength of the epoxy resin can be largely retained at high epoxy resin content in the blend, while increasing the fracture toughness.

  8. Proton exchange membranes based on PVDF/SEBS blends

    Energy Technology Data Exchange (ETDEWEB)

    Mokrini, A.; Huneault, M.A. [Industrial Materials Institute, National Research Council of Canada, 75 de Mortagne Blvd., Boucherville, Que. (Canada J4B 6Y4)

    2006-03-09

    Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene-(ethylene-butylene)-styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology-property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer (MMA-BA-MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9x10{sup -2} to 5.5x10{sup -3}Scm{sup -1}, and improved water management. (author)

  9. Proton exchange membranes based on PVDF/SEBS blends

    Science.gov (United States)

    Mokrini, A.; Huneault, M. A.

    Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene-(ethylene-butylene)-styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology-property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer (MMA-BA-MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2 wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9 × 10 -2 to 5.5 × 10 -3 S cm -1, and improved water management.

  10. Properties and durability of metakaolin blended cements

    Directory of Open Access Journals (Sweden)

    Ezzat, El-Sayed

    2010-09-01

    Full Text Available This paper evaluates the optimal calcination temperature and replacement ratio to ensure high metakaolin (MK pozzolanicity in blended cement. The MK used was prepared by firing two types of local at temperatures ranging from 700 to 850 ºC. Dry blends of ordinary Portland cement (OPC and varying proportions of MK were mixed with the amount of water required to ensure optimal consistency of the resulting pastes. The specimens were cured at 100% RH for 24 h and then immersed in water for 3, 7, 28, 90 or 180 days. At each test time, the degree of hydration and compressive strength of the hardened cement pastes were measured The findings showed that the most suitable calcination temperature to obtain metakaolin is 700 ºC, while the optimal replacement ratio ranges from 25 to 30%. DTA was used to determine the phases comprising the hydration products forming at the ages studied. Pure OPC and OPC-MK specimens were immersed in 3% NaCl and 5% MgSO4 solutions for 30, 90 and 180 days to measure their durability. The OPC-MK pastes immersed in the 3% NaCl solution were observed to be highly resistant to chloride attack.

    El presente trabajo evalúa el comportamiento puzolánico de metacaolín (MK, producto de la calcinación a distintas temperaturas de dos tipos de caolín local de composiciones químicas diferentes, al incorporarse al cemento en diferentes proporciones. Se preparó un cemento adicionado mediante la mezcla en seco de cemento Portland ordinario (OPC y metacaolín (MK, a los que se añadió la cantidad óptima de agua para obtener una pasta de la consistencia deseada. Las probetas se curaron a una HR del 100% durante 24 horas, sumergiéndose posteriormente en agua durante 3, 7, 28, 90 o 180 días. A cada tiempo de ensayo se controló el grado de hidratación de las pastas endurecidas y se comprobó la resistencia a la compresión de las probetas cúbicas a las edades de curado establecidas. Los resultados obtenidos indican que la

  11. Glass powder blended cement hydration modelling

    Science.gov (United States)

    Saeed, Huda

    The use of waste materials in construction is among the most attractive options to consume these materials without affecting the environment. Glass is among these types of potential waste materials. In this research, waste glass in powder form, i.e. glass powder (GP) is examined for potential use in enhancing the characteristics of concrete on the basis that it is a pozzolanic material. The experimental and the theoretical components of the work are carried out primarily to prove that glass powder belongs to the "family" of the pozzolanic materials. The chemical and physical properties of the hydrated activated glass powder and the hydrated glass powder cement on the microstructure level have been studied experimentally and theoretically. The work presented in this thesis consists of two main phases. The first phase contains experimental investigations of the reaction of glass powder with calcium hydroxide (CH) and water. In addition, it includes experiments that are aimed at determining the consumption of water and CH with time. The reactivity, degree of hydration, and nature of the pore solution of the glass powder-blended cement pastes and the effect of adding different ratios of glass powder on cement hydration is also investigated. The experiments proved that glass powder has a pozzolanic effect on cement hydration; hence it enhances the chemical and physical properties of cement paste. Based on the experimental test results, it is recommended to use a glass powder-to-cement ratio (GP/C) of 10% as an optimum ratio to achieve the best hydration and best properties of the paste. Two different chemical formulas for the produced GP C-S-H gel due to the pure GP and GP-CH pozzolanic reaction hydration are proposed. For the pure GP hydration, the produced GP C-S-H gel has a calcium-to-silica ratio (C/S) of 0.164, water-to-silica ratio (H/S) of 1.3 and sodium/silica ratio (N/S) of 0.18. However, for the GP-CH hydration, the produced GP C-S-H gel has a C/S ratio of 1

  12. Low-Temperature Miscibility of Ethanol-Gasoline-Water Blends in Flex Fuel Applications

    DEFF Research Database (Denmark)

    Johansen, T.; Schramm, Jesper

    2009-01-01

    The miscibility of blends of gasoline and hydrous ethanol was investigated experimentally at - 25 degrees C and - 2 degrees C. Furthermore, the maximum water content was found for ethanol in flex fuel blends. The results strongly indicate that blends containing ethanol with a water content above...... that of the ethanol/water azeotrope (4.4% water by mass) can be used as Flex Fuel blends together with gasoline at ambient temperatures of 25 degrees C and 2 degrees C, without phase separation occurring. Additionally, it was shown that the ethanol purity requirement of ethanol-rich flex fuel blends falls...... with increasing ethanol content in the gasoline-rich flex fuel blend....

  13. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Pairu; Zin, Wan Manshol Wan [Malaysian Nuclear Agency, 43000 kajang, Selangor (Malaysia); Daik, Rusli [Faculty of Science and Technology, Universiti Kebangsaan Malaysia,43600 bangi, Selangor (Malaysia)

    2015-09-25

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  14. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    Science.gov (United States)

    Ibrahim, Pairu; Daik, Rusli; Zin, Wan Manshol Wan

    2015-09-01

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  15. EVA reactive blending with Si-H terminated polysiloxane by carbonyl hydrosilylation reaction: From compatibilised blends to crosslinking networks

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, J.; Bounor-Legare, V.; Alcouffe, P. [Universite de Lyon, 69003 Lyon (France); Universite de Lyon 1, CNRS UMR5223, Ingenierie des Materiaux Polymeres, 15 Boulevard Latarjet, F-69622 Villeurbanne (France); Cassagnau, P., E-mail: philippe.cassagnau@univ-lyon1.fr [Universite de Lyon, 69003 Lyon (France); Universite de Lyon 1, CNRS UMR5223, Ingenierie des Materiaux Polymeres, 15 Boulevard Latarjet, F-69622 Villeurbanne (France)

    2012-10-15

    A new and original method based on carbonyl hydrosilylation was developed to prepare ethylene-vinyl acetate (EVA)/polysiloxane polymer blends. This focused on the addition of hydrogenosilane groups (SiH) from polysiloxane to the carbonyl groups of EVA. The influence of the nature of the polysiloxane on blend properties was investigated by rheology and scanning electron microscopy. Mixing of a low viscosity polysiloxane with a high viscosity EVA matrix produced a two-phase morphology. The occurrence of the hydrosilylation reaction at the EVA/polysiloxane interface promoted a homogenisation of the blend depending on the molar ratio SiH/vinyl acetate groups, [SiH]/[VA], and the viscosity ratio of the blend. Two distinct behaviours were observed. The formation of a crosslinked network under shear was obtained for a low viscosity ratio between polysiloxane and EVA ({lambda}{sub polysiloxane/EVA} = 4.0 Multiplication-Sign 10{sup -6}) with a high concentration of SiH groups ([SiH]/[VA] = 0.5), while the formation of a compatibilised blend was observed for high molar mass polysiloxanes (Mn > 15,000 g mol{sup -1}) with a low concentration of SiH ([SiH]/[VA] < 4.0 Multiplication-Sign 10{sup -3}). -- Highlights: Black-Right-Pointing-Pointer Carbonyl hydrosilylation reaction was found to enhance EVA/polysiloxane immiscible blends. Black-Right-Pointing-Pointer EVA crosslinking was obtained with a low molar mass polysiloxane. Black-Right-Pointing-Pointer EVA compatibilisation was obtained with a high molar mass polysiloxane. Black-Right-Pointing-Pointer Shear rate was found to improve the hydrosilylation reaction at the interface. Black-Right-Pointing-Pointer A two-phase morphology of the blends was observed after reaction with fine polysiloxane nodules.

  16. Pedagogical and Design Aspects of a Blended Learning Course

    Directory of Open Access Journals (Sweden)

    Karen Precel, Yoram Eshet-Alkalai, Yael Alberton

    2009-04-01

    Full Text Available Based on recent research reports, the blended learning model, which combines face-to-face and online learning, is now the preferred model for online course design. Its superiority over online learning, which lacks face-to-face interaction, is evident from studies that examined both student achievement and satisfaction. Nevertheless, there is ambiguity in the literature and in the field regarding the proper implementation of blended learning and the optimal proportions between online and F2F components in various learning scenarios. The range of contradictory reports in recent literature on the potential of different blended learning models shows the need for more research on specific blended learning courses in order to establish proper standards for effective course design and implementation. The present evaluation study focuses on students’ perceptions of pedagogical and design issues related to a new model for blended learning used in a graduate-level course at the Open University of Israel. Fifty-eight of the course’s 91 students participated in the study and completed a questionnaire regarding three major aspects of the course design: (1 pedagogy, (2 textbook format (print vs. digital, and (3 learning environment usability. The results illustrate the importance of completing the pedagogical and visual design of online learning in advance. Also, the course model suggests ways to bridge the gaps between students and instructors and students and their peers, which are typical of online learning in general and of open universities in particular.

  17. blend4php: a PHP API for galaxy.

    Science.gov (United States)

    Wytko, Connor; Soto, Brian; Ficklin, Stephen P

    2017-01-01

    Galaxy is a popular framework for execution of complex analytical pipelines typically for large data sets, and is a commonly used for (but not limited to) genomic, genetic and related biological analysis. It provides a web front-end and integrates with high performance computing resources. Here we report the development of the blend4php library that wraps Galaxy's RESTful API into a PHP-based library. PHP-based web applications can use blend4php to automate execution, monitoring and management of a remote Galaxy server, including its users, workflows, jobs and more. The blend4php library was specifically developed for the integration of Galaxy with Tripal, the open-source toolkit for the creation of online genomic and genetic web sites. However, it was designed as an independent library for use by any application, and is freely available under version 3 of the GNU Lesser General Public License (LPGL v3.0) at https://github.com/galaxyproject/blend4phpDatabase URL: https://github.com/galaxyproject/blend4php.

  18. How to Mix the Ingredients for a Blended Course Recipe

    Directory of Open Access Journals (Sweden)

    Antoanela Naaji

    2015-12-01

    Full Text Available Over the last years, the growing ubiquity of Social Media, the emerging mobile technologies and the augmented reality become more deeply integrated into the teaching-learning process and also create new opportunities for reinventing the way in which educational actors both perceive and access learning. The major challenges in education that involve tremendous development and innovation are blended courses/ flipped classrooms integrating Social Media (SM, Open Educational Resources (OER and Massive Open Online Courses (MOOC (Johnson et al., 2014. This paper focuses on evaluating the e-learning experiences of various actors in the Romanian educational system. There is a tendency to use virtual learning environments with increasing frequency in higher education, many participants experiencing both online and blended courses. Another issue approached in this paper concerns the relevance of the components of online/ blended courses. In this context, the paper analyzes the importance of these elements with respect to various fields, such as: exact sciences, social sciences, humanistic studies, medical sciences, etc. In conclusion, we identify the most relevant elements in the development of online/ blended courses for various domains. The results will emphasize the standards required for evaluating the quality of online and blended courses.

  19. Performance of Diesel Engine Using Blended Crude Jatropha Oil

    Science.gov (United States)

    Kamarudin, Kamarul Azhar; Mohd Sazali, Nor Shahida Akma; Mohd Ali, Mas Fauzi; Alimin, Ahmad Jais; Khir, Saffiah Abdullah

    2010-06-01

    Vegetable oil presents a very promising alternative to diesel oil since it is renewable and has similar properties to the diesel. In view of this, crude jatropha oil is selected and its viscosity is reduced by blending it with diesel. Since jatropha oil has properties which are similar to mineral diesel, it can be used in compression ignition engines without any engine modification. This paper presents the results of investigation carried out on a four-cylinder, four strokes and indirect-injection diesel engine. The engine, operated using composition blends of crude jatropha oil and diesel, were compared with mineral diesel. An experimental investigation has been carried out to analyze the performance characteristics of a compression ignition engine from the blended fuel (5%, 10%, 20% and 30%). A naturally aspirated four-stroke indirect injection diesel engine was tested at full load conditions, speeds between 1000 and 3500 rpm with intervals of 500 rpm. Results obtained from the measures of torque, power, specific fuel consumptions, thermal efficiency and brake mean effective pressure are nearly the same between blended and diesel fuel. An overall graph shows that the performance of relevant parameters from blended fuel is most likely similar to the performance produced from diesel. The experimental results proved that the use of crude jatropha oil in compression ignition engines is a viable alternative to diesel.

  20. Metal oxide blended ZSM-5 nanocomposites as ethanol sensors

    Indian Academy of Sciences (India)

    MADHURI LAKHANE; RAJENDRA KHAIRNAR; MEGHA MAHABOLE

    2016-10-01

    Nano-ZSM-5 is synthesized without organic template via microwave-assisted hydrothermal technique. The synthesized nano-ZSM-5 zeolite is blended with metal oxides (ZnO and TiO$_2$) to have novel composites as ethanol sensors. The composites are characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. A study on ethanol sensing behaviour of metal oxide blended composite screen-printed thick films is carried out and the effect of metal oxide concentration on various ethanol sensing features, specifically operating temperature, response/recovery time and active region of the sensor, are investigated. XRD and FTIR confirm the blending of metal oxides in ZSM-5 matrix. Both, ZnO and TiO$_2$ blended, composite films are sensitive to ethanol. It can be concluded that metal oxide blending improves the preformance of sensor for ethanol detection. The response/recovery time and active sensing regions depend upon the concentration of metal oxide in host zeolite. The ZnO/ZSM-5 and TiO$_2$/ZSM-5 composite films are the excellent ethanol sensors.

  1. Hydration process in Portland cement blended with activated coal gangue

    Institute of Scientific and Technical Information of China (English)

    Xian-ping LIU; Pei-ming WANG; Min-ju DING

    2011-01-01

    This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-cvaporable water measurement,and X-ray diffraction analysis.The results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement blend.The pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate hydrates.These hydrates are similar to those found in pure Portland cement.The results show that if activated coal gangue is substituted for cement at up to 30% (w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a supplementary cementing material.The relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same equation.However,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.

  2. Electrospun gelatin/polyurethane blended nanofibers for wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Eun; Heo, Dong Nyoung; Lee, Jung Bok; Kwon, Il Keun [Department of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Jong Ryul; Park, Sang Hyuk [Conservative Dentistry and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Jeon, Seong Ho, E-mail: kwoni@khu.ac.k [College of Pharmacy, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2009-08-15

    In this study, we prepared a blended nanofiber scaffold using synthetic and natural polymers, polyurethane (PU) and gelatin respectively, using the electrospinning method to prepare a material for wound dressing. In order to confirm the properties of this gelatin/PU blended nanofiber scaffold, we performed scanning electron microscopy, atomic force microscopy, attenuated total reflectance Fourier-transform infrared spectroscopy, thermal gravimetric analysis, contact angle, water uptake, mechanical property, recovery, and degradation tests, and cellular response. The results obtained indicate that the mean diameter of these nanofibers was uniformly electrospun and ranged from 0.4 to 2.1{mu}m. According to the results, when the amount of gelatin in the blended solution decreased, the contact angle increased and water uptake of the scaffold decreased concurrently. In the mechanical tests, the blended nanofibrous scaffolds were elastic, and elasticity increased as the total amount of PU increased. Moreover, as the total amount of gelatin increased, the cell proliferation increased with the same amount of culture time. Therefore, this gelatin/PU blended nanofiber scaffold has potential application for use as a wound dressing.

  3. blend4php: a PHP API for galaxy

    Science.gov (United States)

    Wytko, Connor; Soto, Brian; Ficklin, Stephen P.

    2017-01-01

    Galaxy is a popular framework for execution of complex analytical pipelines typically for large data sets, and is a commonly used for (but not limited to) genomic, genetic and related biological analysis. It provides a web front-end and integrates with high performance computing resources. Here we report the development of the blend4php library that wraps Galaxy’s RESTful API into a PHP-based library. PHP-based web applications can use blend4php to automate execution, monitoring and management of a remote Galaxy server, including its users, workflows, jobs and more. The blend4php library was specifically developed for the integration of Galaxy with Tripal, the open-source toolkit for the creation of online genomic and genetic web sites. However, it was designed as an independent library for use by any application, and is freely available under version 3 of the GNU Lesser General Public License (LPGL v3.0) at https://github.com/galaxyproject/blend4php. Database URL: https://github.com/galaxyproject/blend4php PMID:28077564

  4. Silk fibroin membranes from solvent-crystallized silk fibroin/gelatin blends: Effects of blend and solvent composition

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Eun S. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Frankowski, David J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Hudson, Samuel M. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Spontak, Richard J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States) and Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: Rich_Spontak@ncsu.edu

    2007-04-15

    Protein membranes have been prepared by mixing gelatin (G) with Bombyx mori silk fibroin (SF) and using aqueous methanol (MeOH) to induce SF crystallization. Amorphous blends of these polymers appear quasi-homogeneous, as discerned from visual observation, electron microscopy and Fourier-transform infrared (FTIR) spectroscopy. Upon subsequent exposure to aqueous MeOH, SF undergoes a conformational change from random-coil to {beta}-sheet. This transformation occurs in pure SF, as well as in each of the G/SF blends, as discerned from FTIR spectroscopy and thermal calorimetry. The influence of MeOH-induced SF crystallization on structure and property development has been measured as functions of blend and solvent composition. By preserving a support scaffold above the G helix-to-coil transition temperature, the formation of crystalline SF networks in G/SF blends can be used to stabilize G-based hydrogels or generate SF membranes for biomaterial, pharmaceutical and gas-separation purposes. The present study not only examines the properties of G/SF blends before and after SF crystallization, but also establishes the foundation for future research into thermally-responsive G/SF bioconjugates.

  5. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  6. Photophysics of charge transfer in a polyfluorene/violanthrone blend

    Science.gov (United States)

    Cabanillas-Gonzalez, J.; Virgili, T.; Lanzani, G.; Yeates, S.; Ariu, M.; Nelson, J.; Bradley, D. D. C.

    2005-01-01

    We present a study of the photophysical and photovoltaic properties of blends of violanthrone in poly[9, 9-bis (2-ethylhexyl)-fluorene-2, 7-diyl ] (PF2/6) . Photoluminescence quenching and photocurrent measurements show moderate efficiencies for charge generation, characteristic of such polymer/dye blends. Pump-probe measurements on blend films suggest that while ˜47% of the total exciton population dissociates within 4ps of photoexcitation, only ˜32% subsequently results in the formation of dye anions. We attribute the discrepancy to the likely formation of complex species with long lifetimes, such as stabilized interface charge pairs or exciplexes. This conclusion is supported by the appearance of a long lifetime component of 2.4ns in the dynamics of the photoinduced absorption signal associated to polarons in photoinduced absorption bands centered at 560nm .

  7. Compatibility of novel blends from polyolefin and coal

    Institute of Scientific and Technical Information of China (English)

    YANG Fu-sheng(杨伏生); ZHOU An-ning(周安宁)

    2004-01-01

    Melt blends of low-density polyethylene(LDPE), ethylene vinyl acetate(EVA) and coal with various compositions were prepared through reactive extrusion. The rheological behaviour was studied with respect to the effect of blend ratio, shear rate using a rheometer to gain an understanding of processing parameters controlling industrial application. Compatibility was also evaluated by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM). The results revealed that LDPE/EVA/coal is a partly compatible system showing pseudo-plastic behaviour, increase in viscosity with increased coal content appeares evident only at low shear rate region, viscosity tends to keep consistent approximately but irrelates to coal content at higher shear rate. Blends viscosity and compatibility are attibuted to changes in LDPE crystalline structure and entanglement, together with interaction between macromolecular aliphatic chains in coal and amorphous phase in LDPE and EVA at the boundaries of phases, which comes forth during the rearrangement process of the crystalline structure.

  8. Study of Blended Learning Process in Education Context

    Directory of Open Access Journals (Sweden)

    Asif Irshad Khan

    2012-09-01

    Full Text Available Education is one of the areas that are experiencing phenomenal changes as a result of the advancement and use of information technology. Mobile and e-learning are already facilitating the teaching and learning experience with the use of latest channels and technologies. Blended learning is a potential outcome of advanced technology based learning system. The charm of blended learning approach lies in the adaptation of technology aided learning methods in addition to the existing traditional based learning. With the introduction of technology, the overall learning as well as teaching experience is considerably enhanced by covering negative aspects of the traditional approach. In this paper a blended learning model for higher education where traditional classroom lectures are supported via e-learning.

  9. Morphological Control Agent in Ternary Blend Bulk Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Hsueh-Chung Liao

    2014-11-01

    Full Text Available Bulk heterojunction (BHJ organic photovoltaic (OPV promise low cost solar energy and have caused an explosive increase in investigations during the last decade. Control over the 3D morphology of BHJ blend films in various length scales is one of the pillars accounting for the significant advance of OPV performance recently. In this contribution, we focus on the strategy of incorporating an additive into BHJ blend films as a morphological control agent, i.e., ternary blend system. This strategy has shown to be effective in tailoring the morphology of BHJ through different inter- and intra-molecular interactions. We systematically review the morphological observations and associated mechanisms with respect to various kinds of additives, i.e., polymers, small molecules and inorganic nanoparticles. We organize the effects of morphological control (compatibilization, stabilization, etc. and provide general guidelines for rational molecular design for additives toward high efficiency and high stability organic solar cells.

  10. Regenerated cellulose/wool blend enhanced biomimetic hydroxyapatite mineralization.

    Science.gov (United States)

    Salama, Ahmed; El-Sakhawy, Mohamed

    2016-11-01

    The current article investigates the effect of bioactive cellulose/wool blend on calcium phosphate biomimetic mineralization. Regenerated cellulose/wool blend was prepared by dissolution-regeneration of neat cellulose and natural wool in 1-butyl-3-methyl imidazolium chloride [Bmim][Cl], as a solvent for the two polymers. Crystalline hydroxyapatite nanofibers with a uniform size, shape and dimension were formed after immersing the bioactive blend in simulated body fluid. The cytotoxicity of cellulose/wool/hydroxyapatite was studied using animal fibroblast baby hamster kidney cells (BHK-21) and the result displayed good cytocompatability. This research work presents a green processing method for the development of novel cellulose/wool/hydroxyapatite hybrid materials for tissue engineering applications.

  11. Tools, perspectives and avatars in blended reality space.

    Science.gov (United States)

    Hoshi, Kei; Pesola, Ulla-Maija; Waterworth, Eva L; Waterworth, John

    2009-01-01

    Blended Reality Space is our term for an interactive mixed-reality environment where the physical and the virtual are intimately combined in the service of interaction goals and communication environments aimed at health support and rehabilitation. The present study examines the effect on rated presence and self-presence of three key factors in the way blended realities may be implemented for these purposes. Our findings emphasize the importance of tangibility for presence, but suggest that presence and self-presence are unrelated phenomena. These findings will be incorporated into design principles for our planned work to develop free movement-based interactions for motor rehabilitation as well as blended-reality spaces for collaboration between hospitals, care organizations, and the home.

  12. Study on Tough Blends of Polylactide and Acrylic Impact Modifier

    Directory of Open Access Journals (Sweden)

    Xiaoli Song

    2014-02-01

    Full Text Available Acrylic impact modifiers (ACRs with different soft/hard monomer ratios (mass ratios were prepared by semi-continuous seed emulsion copolymerization using the soft monomer butyl acrylate and the hard monomer methyl methacrylate, which were used to toughen polylactide (PLA. The effect of soft/hard ACR monomer ratio on the mechanical properties of PLA/ACR blends was investigated. The results showed that the impact strength and the elongation at break of PLA/ACR blends increased with increasing soft/hard ACR monomer ratio, while the tensile and flexural strengths of PLA had little change. The impact strength of PLA/ACR blends could be increased about 4 times more than that of pure PLA when the soft/hard monomer ratio of ACR was 90/10, which was the optimal ratio for good mechanical properties of PLA. Additionally, the possible mechanism of ACR toughening in PLA was discussed through impact fracture phase morphology analysis.

  13. Polyethylene crystallization in compatibilized polyethylene/polyamide 6 blends

    Science.gov (United States)

    Ceccia, Simona; Hynstova, Katerina; Fabre, Alexandra; Trouillet-Fonti, Lise; Long, Didier; Sotta, Paul

    2011-03-01

    Blends of semicrystalline polymers can exhibit much better properties than each of the pure polymers regarding e.g. impact/modulus compromise. Controlling the crystallization mechanisms (nucleation, kinetics) is a key factor to obtain the desired morphologies which lead to these unique properties. We have studied the crystallization of polyethylene (PE) in blends of PE and polyamide 6 (PA) compatibilized by PE functionalized with maleic anhydride (PE-g-MA, 1 wt% MA) obtained by reactive blending. Samples with different amounts of PA6 (0-60 %vol) have been investigated by polarized optical microscopy and Differential Scanning Calorimetry. The samples were heated at a temperature above the melting temperature of PE and below the melting temperature of PA, and then cooled at the selected crystallization temperature. We describe how the crystallization kinetics is modified by the presence of PA and MA.

  14. Evaluation of photodegradation in LDPE/modified starch blends

    Directory of Open Access Journals (Sweden)

    Flávia G. D. Ferreira

    2009-01-01

    Full Text Available Photodegradation of LDPE/modified starch blends 80/20 m/m has been examined by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR and X ray diffraction (DRX before and after exposure to ultraviolet radiation (UV. Samples were exposed to UV in the laboratory for periods of 6, 24, 48 and 60 hours. The main alteration in the polymeric material after exposure to the radiation was a decrease in the mechanical properties, tensile strength and elongation. There were also changes in the chemical structure of the blend with an increase in the carbonyl and vinyl indices, 65.58 and 53.29%, respectively. The analysis of the blend crystallinity pointed to the formation of a new crystalline symmetry that did not exist before the irradiation.

  15. Framework for compulsory teacher training in blended learning

    DEFF Research Database (Denmark)

    Stenalt, Maria Hvid; Nielsen, Tobias Alsted

    2016-01-01

    This paper presents a framework for approaching the design of compulsory teacher training in blended learning. Rather than being prescriptive with regards to blended learning usage and impact, the design is adjustable to various teacher approaches to teaching, resistance to change, teaching...... is used successfully in a one-year long teacher training programme in blended learning developed at Aarhus University in Denmark. Aarhus University (AU) adopted a 'Educational IT’ policy in 2011 with the purpose of strengthening teaching and learning through use of online interactions. The policy...... prescribes that 60 percent of all teachers at AU must be offered competence development regarding e-learning and teaching with digital media within 3 years. In 2012 the Dean’s Office at Aarhus University, School of Business and Social Sciences (Aarhus BSS), one of the four faculties at the university...

  16. Controlled differential pressure system for an enhanced fluid blending apparatus

    Science.gov (United States)

    Hallman, Jr., Russell Louis

    2009-02-24

    A system and method for producing a controlled blend of two or more fluids. Thermally-induced permeation through a permeable tube is used to mix a first fluid from outside the tube with a second fluid flowing through the tube. Mixture ratios may be controlled by adjusting the temperature of the first fluid or by adjusting the pressure drop through the permeable tube. The combination of a back pressure control valve and a differential regulator is used to control the output pressure of the blended fluid. The combination of the back pressure control valve and differential regulator provides superior flow control of the second dry gas. A valve manifold system may be used to mix multiple fluids, and to adjust the volume of blended fluid produced, and to further modify the mixture ratio.

  17. Molecular rheological analysis on binary blends of perfluoropolyether lubricants

    Science.gov (United States)

    Seung Chung, Pil; Hari Vemuri, Sesha; Park, Sejoon; Jhon, Myung S.

    2014-05-01

    The molecular rheology of PFPE becomes critically important in designing optimal lubricants that control the friction/wear and air-bearing by tuning elastic or viscous shear/elongation deformations, which affect the performance and reliability of the hard disk drive. In this paper, we examine the rheological responses of nano blended PFPEs including storage (elastic) and loss (viscous) moduli (G' and G″), by monitoring the time-dependent-stress-strain relationship via non-equilibrium molecular dynamics simulations. By introducing binary blend of nonfunctional and functional PFPEs, we control the degree of liquid/solid-like behavior using the rheology as a complementary tool for design criteria by tuning molecular conformation and diffusion with nano blend ratio.

  18. Pyrolysis and combustion behaviour of coal-MBM blends.

    Science.gov (United States)

    Skodras, G; Grammelis, P; Basinas, P

    2007-01-01

    In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content.

  19. Pyrolysis and combustion behaviour of coal-MBM blends

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Grammelis, P.; Basinas, P. [Center for Research & Technology Hellas, Ptolemais (Greece)

    2007-01-15

    In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM (meat and bone meal) and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content.

  20. Interdiffusion and Spinodal Decomposition in Electrically Conducting Polymer Blends

    Directory of Open Access Journals (Sweden)

    Antti Takala

    2015-08-01

    Full Text Available The impact of phase morphology in electrically conducting polymer composites has become essential for the efficiency of the various functional applications, in which the continuity of the electroactive paths in multicomponent systems is essential. For instance in bulk heterojunction organic solar cells, where the light-induced electron transfer through photon absorption creating excitons (electron-hole pairs, the control of diffusion of the spatially localized excitons and their dissociation at the interface and the effective collection of holes and electrons, all depend on the surface area, domain sizes, and connectivity in these organic semiconductor blends. We have used a model semiconductor polymer blend with defined miscibility to investigate the phase separation kinetics and the formation of connected pathways. Temperature jump experiments were applied from a miscible region of semiconducting poly(alkylthiophene (PAT blends with ethylenevinylacetate-elastomers (EVA and the kinetics at the early stages of phase separation were evaluated in order to establish bicontinuous phase morphology via spinodal decomposition. The diffusion in the blend was followed by two methods: first during a miscible phase separating into two phases: from the measurement of the spinodal decomposition. Secondly the diffusion was measured by monitoring the interdiffusion of PAT film into the EVA film at elected temperatures and eventually compared the temperature dependent diffusion characteristics. With this first quantitative evaluation of the spinodal decomposition as well as the interdiffusion in conducting polymer blends, we show that a systematic control of the phase separation kinetics in a polymer blend with one of the components being electrically conducting polymer can be used to optimize the morphology.

  1. 40 CFR 418.70 - Applicability; description of the mixed and blend fertilizer production subcategory.

    Science.gov (United States)

    2010-07-01

    ... and blend fertilizer production subcategory. 418.70 Section 418.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production Subcategory § 418.70 Applicability; description...

  2. Controlled release of tocopherols from polymer blend films

    Science.gov (United States)

    Obinata, Noe

    Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies

  3. Blended Learning in Higher Education: Theory and Praxis

    OpenAIRE

    Reinmann, G.; MacDonald, J; Donnelly, Roisin; Fransen, J; Poldner, E.

    2007-01-01

    Recent studies are showing that ‘blended learning’ is more than a mix between face-to-face and online education, or in other words: a mix of traditional and computer-based education. Blended learning seems to include mixtures between eLearning and other ways of learning, where the right choices have to be made in the distribution of learning content, didactical approaches, ways of communicating and characteristics of learning environments, in the perspective of the type of learning process an...

  4. NMR STUDY ON THE COMPATIBILITY OF ACR/PVC BLENDS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoqing; QIU Lingshi; WANG Dongsheng; WANG Yuanshen

    1988-01-01

    A 300MHz solid NMR study on the compatibility of ACR (poly (methyl methacrylate-co-methacrylate),in the ratio of 1:1)-PVC (poly (vinyl chloride)) blends is reported. Spin-lattice (T1) and spin-spin (T2)relaxation time of ACR, PVC and their blends are recorded in the temperature range from 215K to 355K.Experimental results indicate that ACR and PVC are compatible with each other and the domain size is smaller than 25 nm, but heterogeneities of molecular dimensions still exist. Some problems of mechanism of compatibility and data analysis are also discussed.

  5. Radiation improvement of PS/LDPE blends with SBS compatibilizer

    Energy Technology Data Exchange (ETDEWEB)

    Chaisupakitsin, M.; Suwanapayom, S. [Department of Chemistry, Faculty of Science, King Mongkut' s Institute of Technology, Lardkrabang Bangkok (Thailand)

    2000-03-01

    Mechanical properties of PS(polystyrene)/LDPE(low density polyethylene) blends with and without SBS compatibilizer were investigated after {gamma}-irradiation at dose range of 10-240 kGy under air atmospheric pressure. It was found that elongation at break and impact strength of the blends were mainly depended on the amount of the compatibilizer. On the other hand, tensile strength was improved by {gamma}-irradiation, particularly, at dose range of 40-180 kGy. Gel fraction was found to increased with increasing compatibilizer and irradiation dose. (author)

  6. Interaction features of petrographically heterogeneous coals in carbonization blends

    Energy Technology Data Exchange (ETDEWEB)

    Stankevich, A.S.; Proskuryakov, A.E.; Zolotukhin, Yu.A.

    1983-01-01

    To establish a clear correlation between the coking quality of coals and blends and their microlithotype constitution, typical Kuzbas coals were examined under a reflected light ore microscope and a complex descriptive parameter was sought. Distinctions were made between the following microlithotypes: vitrite, clarite, duroclarite, clarodurite, durite, fusite, semivitrinite, mineralized coal, and dirt. Multiple regression equations were developed which adequately describe the correlations between the visco-plastic property indices of coal blends, the quality of the coke, the x-ray structural parameters, and the petrographic parameters of the coals. With the help of these equations the behavior of microlithotypes during carbonization of coal was discussed.

  7. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    OpenAIRE

    M. MARINOVIC-CINCOVIC; J. BUDINSKI SIMENDIC; Markovic, G.; Radovanovic, B.

    2005-01-01

    The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV) and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40) blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microsc...

  8. Dispersion-strengthened Aluminium Products Manufactured by Powder Blending

    DEFF Research Database (Denmark)

    Hansen, Niels

    1969-01-01

    Detailed experiments carried out to examine relationship between microstructure and mechanical properties of powder-blended aluminum products are reported; their results as well as structural studies by transmission electron microscopy and tensile-and creep- testing, are given; as dispersed phase......, various oxide powders were selected on criterion that during manufacturing no reaction must taken place between metal and oxide phase; strength of powder-blended aluminum products increases and elongation decreases with decreasing particle size of aluminum powder and with increasing concentration of oxide...

  9. Blended Learning与研究生外语教学

    Institute of Scientific and Technical Information of China (English)

    耿静先

    2011-01-01

    Blended Learning(混合式学习)的精髓是把传统课堂教学和多媒体网络教学的优势结合起来.在研究生外语教学中应用Blended Learning理论,就要求在课程设置、教学模式、教学方法和教学评估等方面,把不同的教学要素适时、适地的混合起来,以达到最佳教学效果.

  10. Perception of Blended Learning Inventory (PoBLi)

    DEFF Research Database (Denmark)

    Lassesen, Berit; Stenalt, Maria Hvid; Rossen, Dorte Sidelmann

    -to-face med online læring (Blended Learning). I et studie fandt Ellis og kolleger (2006), at undervisere, der overvejende havde opfattelsen af, at de studerende lærte ved, at han/hun formidlede viden til dem, havde en simpel, fragmenteret opfattelse af potentialet ved BL. Derimod syntes en mere......) underviseres oplevelse af undervisningsmiljøet Resultater: Spørgeskema og resultaterne af de foreløbige analyser vil blive præsenteret og diskuteret. Perspektiver: PoBLi-projektet vil bidrage til den eksisterende forskning vedrørende rationalet for inddragelse af blended learning-formatet i...

  11. Use of Blended Approach in the Learning of Electromagnetic Induction

    CERN Document Server

    Chew, Charles

    2015-01-01

    This paper traces the importance of pedagogical content knowledge in the digital age to prepare today students for the 21st century. It highlights the need for ICT-based pedagogical models that are grounded in both the learning theories of constructivism and connectivism. One such suitable ICT-based pedagogical model is the TSOI Hybrid Learning Model. By means of a physics blended learning exemplar based on the TSOI Hybrid Learning Model, this paper argues for the use of blended learning approach as the way forward for 21st century teaching.

  12. Pedagogical and Technological Perspective in Convergence Blended Learning

    Directory of Open Access Journals (Sweden)

    Osbaldo Turpo Gebera

    2014-04-01

    Full Text Available Since its emergence in the educational context, the blended learning insurgentas a modality with its own identity. According to its evolution, runs through presentiality configured contexts and virtuality. In a first stage, stood as a mixed or combined mode, and then advanced to integration, which resulted in the dilutionof its components. The progressive social changes, technological and cultural towards convergence, today brings a new north-mode, given the confluence of pedagogical and technological mediations in the training process. This position places him in a new trend that more than a possibility, actually represents a more explicable on the future of Blended Learning.

  13. The Blended Finite Element Method for Multi-fluid Plasma Modeling

    Science.gov (United States)

    2016-07-01

    Briefing Charts 3. DATES COVERED (From - To) 07 June 2016 - 01 July 2016 4. TITLE AND SUBTITLE The Blended Finite Element Method for Multi-fluid Plasma ...BLENDED FINITE ELEMENT METHOD FOR MULTI-FLUID PLASMA MODELING Éder M. Sousa1, Uri Shumlak2 1ERC INC., IN-SPACE PROPULSION BRANCH (RQRS) AIR FORCE RESEARCH...MULTI-FLUID PLASMA MODEL 2 BLENDED FINITE ELEMENT METHOD Blended Finite Element Method Nodal Continuous Galerkin Modal Discontinuous Galerkin Model

  14. STUDY ON THE MISCIBILITY OF DYNAMICALLY VULCANIZED EPDM/PP BLEND BY POSITRON ANNIHILATION SPECTROSCOPY

    Institute of Scientific and Technical Information of China (English)

    Tao Jiang; Xue-liang Jiang; Shi-yuan Cheng; Yi-qun Dai; Shao-jie Wang; Bo Wang

    2000-01-01

    Positron annihilation spectroscopy (PAS) was utilized to investigate the relationship between the free-volume hole properties and miscibility of dynamically vulcanized EPDM/PP blend. The results showed that the noncrystalline region of PP and EPDM in the blend was partially miscible and the miscibility of the blend became worse when the weight percent of EPDM was <50%. This was also demonstrated by DMTA and mechanical properties of the blends with various compositions.

  15. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid)

    OpenAIRE

    Guoquan Zhu; Fagang Wang; Qiaochun Gao; Yuying Liu

    2013-01-01

    In this study, a series of poly(γ-benzyl L-glutamate)/poly(acrylic acid) (PBLG/PAA) polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO). The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC), Thermogra...

  16. Blending Learning和信息技术与课程整合%Blending learning and information technology curriculum integration

    Institute of Scientific and Technical Information of China (English)

    董文君

    2006-01-01

    随着对E-learning的研究转入低潮,人们开始冷静思考总结经验教训,于是将传统课堂教育和E-learning的优势相结合,产生了Blending Learning的概念.而现今学校教育中最红火的莫过于信息技术与课程整合,这符合素质教育以及21世纪人才培养目标的要求.本文拟从Blending Learning为信息技术与课程整合带来的新启示这个角度着手,探讨如何将Blending Learning的思想融入课程整合中,以期为整合带来新思路、扩展新道路.

  17. Characterization of particle size distribution from diesel engines fueled with palm-biodiesel blends and paraffinic fuel blends

    Science.gov (United States)

    Lin, Yuan-Chung; Lee, Chia-Fon; Fang, Tiegang

    Biodiesels are promoted as alternative fuels and their applications in diesel engines have been investigated by many researchers. However, the particle size distribution emitted from heavy-duty diesel engines fueled with palm-biodiesel blended with premium diesel fuel and paraffinic fuel blended with palm-biodiesel has seldom been addressed. Thus, five test fuels were used in this work to study the particle size distribution: D100 (premium diesel fuel), B100 (100% palm-biodiesel), B20 (20 vol% palm-biodiesel+80 vol% D100), BP9505 (95 vol% paraffinic fuel+5 vol% palm-biodiesel) and BP8020 (80 vol% paraffinic fuel+20 vol% palm-biodiesel). A Micro-Orifice Uniform Deposit Impactor (MOUDI) equipped with aluminum filters was used to collect size-resolved samples. Experimental results indicated that palm-biodiesel blends and paraffinic fuel blends could improve combustion efficiency in diesel engines, but pure palm-biodiesel could cause incomplete combustion. Adding palm-biodiesel to diesel fuel would slightly increase particles with diameter matter of BP9505 and BP8020 existed in coarse particles (diameter: 2.5-10 μm). Energy efficiency also increases significantly by 12.3-15.1% with the introduction of paraffinic fuel blends into the engine. Nevertheless, paraffinic fuel blends also reduce the emission of particulate matters by 36.0-38.4%. Carbon monoxide was decreased by 36.8-48.5%. Total hydrocarbon is 39.6-41.7% less than diesel fuel combustion. Nitrogen oxides emission is about 5% lower for paraffinic fuel. These results show that paraffinic fuel can be very competitive and replaced diesel fuels in the future.

  18. Educators' Perceptions, Attitudes and Practices: Blended Learning in Business and Management Education

    Science.gov (United States)

    Benson, Vladlena; Anderson, Deborah; Ooms, Ann

    2011-01-01

    Adoption of blended learning is a complex process for higher education institutions and academic staff. Although the move towards blended learning is generally instigated at institutional level, factors determining its success and minimising resistance of faculty often emerge at delivery level. This paper explores adoption of blended learning…

  19. Evaluating Student Satisfaction with Blended Learning in a Gender-Segregated Environment

    Science.gov (United States)

    Naaj, Mahmoud Abou; Nachouki, Mirna; Ankit, Ahmed

    2012-01-01

    Blended learning combines multiple delivery media that are designed to complement each other and promote learning and application-learned behavior (Smith & Dillon, 1999). This article reports on a study conducted in the College of Information Technology to evaluate levels of student' satisfaction with blended learning. The particular blend of…

  20. Influence of diblock copolymer on the morphology and properties of polystyrene/poly(dimethylsiloxane) blends

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Li, Shu; Almdal, Kristoffer;

    2004-01-01

    Blends of polystyrene (PS) and poly(dimethylsiloxane) (PDMS), with and without diblock copolymers (PS-b-PDMS), were prepared by melt mixing. The melt rheology behavior of the blends was studied with a capillary rheometer. The morphology of the blends was examined with scanning electron microscopy...

  1. Sociotechnical Systems Approach: An Internal Assessment of a Blended Doctoral Program

    Science.gov (United States)

    Erichsen, Elizabeth Anne; DeLorme, Lyn; Connelley, Rosalinda; Okurut-Ibore, Christine; McNamara, Lisa; Aljohani, Obaidalah

    2013-01-01

    An internal assessment was conducted utilizing a sociotechnical systems approach and cultural lens as a means of exploring the dynamics of a blended doctoral program. Blended learning environments were conceived of as sociotechnical systems, and blended programs were defined as programs that utilize multimodal means for the mediation of…

  2. 76 FR 78290 - Cooperative Research and Development Agreement: Usage of Biodiesel Fuel Blends Within Marine...

    Science.gov (United States)

    2011-12-16

    ... SECURITY Coast Guard Cooperative Research and Development Agreement: Usage of Biodiesel Fuel Blends Within... technology enhancements, performance, costs, and other issues associated with using biodiesel fuel blends in... notice (investigating the use of biodiesel fuel blends in marine inboard engines) must reach the...

  3. Enacting Conceptual Metaphor through Blending: Learning Activities Embodying the Substance Metaphor for Energy

    Science.gov (United States)

    Close, Hunter G.; Scherr, Rachel E.

    2015-01-01

    We demonstrate that a particular blended learning space is especially productive in developing understanding of energy transfers and transformations. In this blended space, naturally occurring learner interactions like body movement, gesture, and metaphorical speech are blended with a conceptual metaphor of energy as a substance in a class of…

  4. Computer-aided approach for design of tailor-made blended products

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza; Gernaey, Krist; Woodley, John;

    2012-01-01

    A computer-aided methodology has been developed for the design of blended (mixture) products. Through this methodology, it is possible to identify the most suitable chemicals for blending, and “tailor” the blend according to specified product needs (usually product attributes, e.g. performance as...

  5. A systematic methodology for design of tailor-made blended products

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza Binti; Gernaey, Krist; Woodley, John;

    2014-01-01

    A systematic methodology for design of tailor-made blended products has been developed. In tailor-made blended products, one identifies the product needs and matches them by blending different chemicals. The systematic methodology has four main tasks. First, the design problem is defined...

  6. Partially fluorinated arylene polyethers and their ternary blend membranes with PBI and H3PO4

    DEFF Research Database (Denmark)

    Kerres, J.; Schonberger, F.; Chromik, A;

    2008-01-01

    ionomer has been blended with poly(2,2'-mphenylene-5,5'-bibenzimidazole) (PBI), yielding base-acid blends with PBI in excess. The base-acid blend membranes have been characterised in terms of solubility in DMAc, water uptake and oxidative stability by immersion in aqueous 5 wt.-% H2O2 solutions and Fenton...

  7. Blended Learning Environments in Higher Education: A Case Study of How Professors Make It Happen

    Science.gov (United States)

    King, Sarah E.; Arnold, Katie Cerrone

    2012-01-01

    Blended learning has become a prominent method of course content delivery in higher education. Researchers have found that motivation, communication, and course design are three factors that contribute to the overall success of blended learning courses and students' satisfaction with blended learning courses. This qualitative study also found that…

  8. Revisiting the Blended Learning Literature: Using a Complex Adaptive Systems Framework

    Science.gov (United States)

    Wang, Yuping; Han, Xibin; Yang, Juan

    2015-01-01

    This research has two aims: (1) to bridge a gap in blended learning research--the lack of a systems approach to the understanding of blended learning research and practice, and (2) to promote a more comprehensive understanding of what has been achieved and what needs to be achieved in blended learning research and practice. To achieve these aims,…

  9. Global Blended Learning Practices for Teaching and Learning, Leadership and Professional Development

    Science.gov (United States)

    Hilliard, Ann Toler

    2015-01-01

    Blended learning is a combination of online and face-to-face activities for classroom instruction or other training modalities to help develop new knowledge and skills that can be transferred to the workplace environment. The use of blended learning is expanding globally (Vaughn, 2007). Blended learning is evident in professional development…

  10. An Analysis of High Impact Scholarship and Publication Trends in Blended Learning

    Science.gov (United States)

    Halverson, Lisa R.; Graham, Charles R.; Spring, Kristian J.; Drysdale, Jeffery S.

    2012-01-01

    Blended learning is a diverse and expanding area of design and inquiry that combines face-to-face and online modalities. As blended learning research matures, numerous voices enter the conversation. This study begins the search for the center of this emerging area of study by finding the most cited scholarship on blended learning. Using Harzing's…

  11. Development and Validation of the Blended Learning Environment Instrument (BLEI) in Higher Education

    Science.gov (United States)

    Aljahni, Areej; Al-Begain, Khalid; Skinner, Heather

    2014-01-01

    Part of ongoing research into the efficacy of blended learning in higher education within the Kingdom of Saudi Arabia (KSA). The need for, and development of, a Blended Learning Environment Instrument (BLEI) are explained. This new instrument assesses student perceptions across five core aspects of blended learning environments: Infrastructure,…

  12. EFL Secondary School Teachers' Views on Blended Learning in Tabuk City

    Science.gov (United States)

    Alfahadi, Abdulrahman M.; Alsalhi, Abdulrhman A.; Alshammari, Abdullah S.

    2015-01-01

    The aim of this study is to investigate EFL Secondary School Teachers' Views on Blended Learning. It also aims to investigate (a) the teachers' views on blended learning content and process, and (b) how blended learning is effective in developing teachers' performance. The study sample included 35 EFL Saudi teachers in Tabuk City, KSA. In order to…

  13. The Impact of Leadership Support for Blended Learning on Teachers and Students

    Science.gov (United States)

    Bodden-White, Michelle Marie

    2015-01-01

    This quantitative study examined the relationship between teachers' perceptions of leadership support for their use of a blended learning approach to teach math in fourth or fifth grade and their use of blended learning. The study also examined teachers' perceptions of leadership support for incorporating blended learning and student engagement.…

  14. A Case Study of the Introductory Psychology Blended Learning Model at McMaster University

    Science.gov (United States)

    Sana, Faria; Fenesi, Barbara; Kim, Joseph A.

    2011-01-01

    This paper provides a brief review of blended learning as a didactic method, and discusses the issues and challenges of using blended learning models in post-secondary education. Blended learning refers to mixed modes of instruction that combine traditional face-to-face classroom teaching methods and online learning materials. The paper will…

  15. An Empirical Evaluation of Critical Factors Influencing Learner Satisfaction in Blended Learning: A Pilot Study

    Science.gov (United States)

    Chen, Won Sun; Yao, Adrian Yong Tat

    2016-01-01

    Blended learning, a convergence of e-learning approach and face-to-face learning, has been regarded as a new paradigm in modern education. The degree of learners' satisfaction with blended learning played a crucial role in evaluating the effectiveness of blended learning adoption. Therefore, this study examined the primary factors affecting…

  16. Presence and Perceived Learning in Different Higher Education Blended Learning Environments

    Science.gov (United States)

    Khodabandelou, Rouhollah; Jalil, Habibah Ab; Ali, Wan Zah Wan; Daud, Shaffe Mohd

    2015-01-01

    Blended learning as "third generation" of distance learning has the potential to offer multimethod instruction through the blend, to leverage the strengths of current online and traditional instructions. Therefore, higher education institutions having recognized the fact that blended learning is beneficial, adopted this alternative…

  17. A View of Blended Learning in ELT Perspective%从大学英语教学透视Blended Learning

    Institute of Scientific and Technical Information of China (English)

    赵丽娟

    2004-01-01

    本文从大学英语教学和Blended Learning的产生、发展等多视角透视其概念内涵;在计算机及网络技术已经全面且实质性地应用于我国英语教学的今天,正确地把握Blended Learning的本质将有助于教育技术在英语教学改革中发挥越来越重要的作用.

  18. Parasitic wasp females are attracted to blends of host-induced plant volatiles: do qualitative and quantitative differences in the blend matter? [v1; ref status: indexed, http://f1000r.es/y3

    Directory of Open Access Journals (Sweden)

    Masayoshi Uefune

    2013-02-01

    Full Text Available Naïve Cotesia vestalis wasps, parasitoids of diamondback moth (DBM larvae, are attracted to a synthetic blend (Blend A of host-induced plant volatiles composed of sabinene, n-heptanal, α-pinene, and (Z-3-hexenyl acetate, in a ratio of 1.8:1.3:2.0:3.0. We studied whether qualitative (adding (R-limonene: Blend B or quantitative changes (changing ratios: Blend C to Blend A affected the olfactory response of C. vestalis in the background of intact komatsuna plant volatiles. Naïve wasps showed equal preference to Blends A and B and Blends A and C in two-choice tests. Wasps with oviposition experience in the presence of Blend B preferred Blend B over Blend A, while wasps that had oviposited without a volatile blend showed no preference between the two. Likewise, wasps that had starvation experience in the presence of Blend B preferred Blend A over Blend B, while wasps that had starved without a volatile blend showed no preference between the two. Wasps that had oviposition experience either with or without Blend A showed equal preferences between Blends C and A. However, wasps that had starvation experience in the presence of Blend A preferred Blend C over Blend A, while those that starved without a volatile blend showed equal preferences between the two. By manipulating quality and quantity of the synthetic attractants, we showed to what extent C. vestalis could discriminate/learn slight differences between blends that were all, in principle, attractive.

  19. Fuel and fuel blending components from biomass derived pyrolysis oil

    Science.gov (United States)

    McCall, Michael J.; Brandvold, Timothy A.; Elliott, Douglas C.

    2012-12-11

    A process for the conversion of biomass derived pyrolysis oil to liquid fuel components is presented. The process includes the production of diesel, aviation, and naphtha boiling point range fuels or fuel blending components by two-stage deoxygenation of the pyrolysis oil and separation of the products.

  20. Blending Classroom Teaching and Learning with QR Codes

    Science.gov (United States)

    Rikala, Jenni; Kankaanranta, Marja

    2014-01-01

    The aim of this case study was to explore the feasibility of the Quick Response (QR) codes and mobile devices in the context of Finnish basic education. The interest was especially to explore how mobile devices and QR codes can enhance and blend teaching and learning. The data were collected with a teacher interview and pupil surveys. The learning…

  1. A Blended Learning Scenario to Enhance Learners' Oral Production Skills

    Science.gov (United States)

    Kim, Hee-Kyung

    2015-01-01

    This paper examines the effectiveness of a mobile assisted blended learning scenario for pronunciation in Korean language. In particular, we analyze how asynchronous oral communication between learners of Korean and native speakers via "kakaotalk" (an open source mobile phone application) may be beneficial to the learner in terms of…

  2. Compatibilization of All-Conjugated Polymer Blends for Organic Photovoltaics.

    Science.gov (United States)

    Lombeck, Florian; Sepe, Alessandro; Thomann, Ralf; Friend, Richard H; Sommer, Michael

    2016-08-23

    Compatibilization of an immiscible binary blend comprising a conjugated electron donor and a conjugated electron acceptor polymer with suitable electronic properties upon addition of a block copolymer (BCP) composed of the same building blocks is demonstrated. Efficient compatibilization during melt-annealing is feasible when the two polymers are immiscible in the melt, i.e. above the melting point of ∼250 °C of the semicrystalline donor polymer P3HT. To generate immiscibility at these high temperatures, the acceptor polymer PCDTBT is equipped with fluorinated side chains leading to an increased Flory-Huggins interaction parameter. Compatibilization in bulk and thin films is demonstrated, showing that the photovoltaic performance of pristine microphase separated and nanostructured BCPs can also be obtained for compatibilized blend films containing low contents of 10-20 wt % BCP. Thermodynamically stable domain sizes range between several tens of microns for pure blends and ∼10 nm for pure block copolymers. In addition to controlling domain size, the amount of block copolymer added dictates the ratio of edge-on and face-on P3HT crystals, with compatibilized films showing an increasing amount of face-on P3HT crystals with increasing amount of compatibilizer. This study demonstrates the prerequisites and benefits of compatibilizing all-conjugated semicrystalline polymer blends for organic photovoltaics.

  3. A New Structural Design Concept for Blended Wing Body Cabins

    NARCIS (Netherlands)

    Vos, R.; Geuskens, F.J.J.M.M.; Hoogreef, M.F.M.

    2012-01-01

    This paper outlines a new concept for a pressure cabin design for blended-wing-body aircraft. An overview is presented of the wide oval cabin and why it is believed to be a possible alternative to existing designs of non-circular pressurized cabins. The perimeter of the oval cross section is formed

  4. Lecturer-Student Communication in Blended Learning Environments

    Science.gov (United States)

    Gecer, Aynur

    2013-01-01

    Blended learning is a flexible approach, which with developing technology, assists in the maintenance of education applications both in the face-to-face environment and on the web. The present study was conducted to determine the perceptions of students who took the Computer-Assisted Mathematics Instruction course about the roles and…

  5. Blended University Teaching Using Virtual Learning Environments: Conceptions and Approaches

    Science.gov (United States)

    Lameras, Petros; Levy, Philippa; Paraskakis, Iraklis; Webber, Sheila

    2012-01-01

    This paper reports findings from a phenomenographic investigation into blended university teaching using virtual learning environments (VLEs). Interviews with 25 Computer Science teachers in Greek universities illuminated a spectrum of teachers' conceptions and approaches from "teacher-focused and content-oriented", through "student-focused and…

  6. Pressure and temperature effects in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Schwahn, D.; Mortensen, K.;

    1997-01-01

    fluctuations. Phase boundaries, the Flory-Huggins interaction parameter and the Ginzburg number were obtained. The packing of the molecules changes with pressure. Therefore, the degree of thermal fluctuation as a function of packing and temperature was studied. While in polymer blends packing leads, in some...... of the entropic and of the enthalpic parts, respectively, of the Flory-Huggins interaction parameter....

  7. Blended Learning in Biochemistry Education: Analysis of Medical Students' Perceptions

    Science.gov (United States)

    Wardenski, Rosilaine de Fatima; de Espindola, Marina Bazzo; Struchiner, Miriam; Giannella, Tais Rabetti

    2012-01-01

    The objective of this study was to analyze first-year UFRJ medical students' perceptions about the implementation of a blended learning (BL) experience in their Biochemistry I course. During the first semester of 2009, three Biochemistry professors used the Constructore course management system to develop virtual learning environments (VLEs) for…

  8. Grindability and combustion behavior of coal and torrefied biomass blends.

    Science.gov (United States)

    Gil, M V; García, R; Pevida, C; Rubiera, F

    2015-09-01

    Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5-55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased.

  9. Encapsulated Presentation: A New Paradigm of Blended Learning

    Science.gov (United States)

    Rose, Richard; Ray, Jan

    2011-01-01

    This article is a presentation of a new mode of blended learning whose only goal is to enrich the quality of instruction in the face-to-face classroom through the simultaneous delivery of online and face-to-face components. Encapsulated presentation is the delivery of the entire presentation phase of a lesson in the classroom by electronic methods…

  10. Predicting morphologies of solution processed polymer:fullerene blends.

    Science.gov (United States)

    Kouijzer, Sandra; Michels, Jasper J; van den Berg, Mauricio; Gevaerts, Veronique S; Turbiez, Mathieu; Wienk, Martijn M; Janssen, René A J

    2013-08-14

    The performance of solution processed polymer:fullerene thin film photovoltaic cells is largely determined by the nanoscopic and mesoscopic morphology of these blends that is formed during the drying of the layer. Although blend morphologies have been studied in detail using a variety of microscopic, spectroscopic, and scattering techniques and a large degree of control has been obtained, the current understanding of the processes involved is limited. Hence, predicting the optimized processing conditions and the corresponding device performance remains a challenge. We present an experimental and modeling study on blends of a small band gap diketopyrrolopyrrole-quinquethiophene alternating copolymer (PDPP5T) and [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM) cast from chloroform solution. The model uses the homogeneous Flory-Huggins free energy of the multicomponent blend and accounts for interfacial interactions between (locally) separated phases, based on physical properties of the polymer, fullerene, and solvent. We show that the spinodal liquid-liquid demixing that occurs during drying is responsible for the observed morphologies. The model predicts an increasing feature size and decreasing fullerene concentration in the polymer matrix with increasing drying time in accordance with experimental observations and device performance. The results represent a first step toward a predictive model for morphology formation.

  11. Interactive point cloud blending by drag-and-drop

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With the rapid development of 3D digital photography and 3D digital scanning devices, massive amount of point samples can be generated in acquisition of complex, real-world objects, and thus create an urgent need for advanced point-based processing and editing. In this paper, we present an interactive method for blending point-based geometries by dragging-anddropping one point-based model onto another model's surface metaphor. We first calculate a blending region based on the polygon of interest when the user drags-and-drops the model. Radial basis function is used to construct an implicit surface which smoothly interpolates with the transition regions. Continuing the drag-and-drop operation will make the system recalculate the blending regions and reconstruct the transition regions. The drag-and-drop operation can be compound in a constructive solid geometry (CSG) manner to interactively construct a complex point-based model from multiple simple ones. Experimental results showed that our method generates good quality transition regions between two raw point clouds and can effectively reduce the rate of overlapping during the blending.

  12. Developing ICT Competency for Thai Teachers through Blended Training

    Science.gov (United States)

    Akarawang, Chaiya; Kidrakran, Pachoen; Nuangchalerm, Prasart

    2016-01-01

    The purpose of this study aims to enhance teachers' ICT competency. Three hundred and thirty seven teachers are surveyed through a questionnaire to identify training problems and training needs. Then the blended training model is implemented with teachers. The result showed that it can increase score in cognitive and attitude tests. The post-test…

  13. Funtionality of Sucralose/Maltodextrin: Isomalt blends in Oatmeal Cookies

    Science.gov (United States)

    Functionality of Sucralose/Maltodextrin:Isomalt blends in Oatmeal Cookies Ruthann B. Swanson1, Rebecca McKemie1, Elizabeth M. Savage2 and Hong Zhuang2 1University of Georgia, Athens, GA 30605; 2ARS-USDA, Athens, GA 30605 Availability of reduced-in-sugar baked products with quality characteristics...

  14. Exploring Intensive Longitudinal Measures of Student Engagement in Blended Learning

    Science.gov (United States)

    Henrie, Curtis R.; Bodily, Robert; Manwaring, Kristine C.; Graham, Charles R.

    2015-01-01

    In this exploratory study we used an intensive longitudinal approach to measure student engagement in a blended educational technology course, collecting both self-report and observational data. The self-report measure included a simple survey of Likert-scale and open-ended questions given repeatedly during the semester. Observational data were…

  15. Course Management Systems and Blended Learning: An Innovative Learning Approach

    Science.gov (United States)

    Chou, Amy Y.; Chou, David C.

    2011-01-01

    This article utilizes Rogers' innovation-decision process model (2003) and Beckman and Berry's innovation process model (2007) to create an innovative learning map that illustrates three learning methods (i.e., face-to-face learning, online learning, and blended learning) in two types of innovation (i.e., incremental innovation and radical…

  16. Intermediate product selection and blending in the food processing industry

    DEFF Research Database (Denmark)

    Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter

    2013-01-01

    This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates...

  17. Training Phoneme Blending Skills in Children with Down Syndrome

    Science.gov (United States)

    Burgoyne, Kelly; Duff, Fiona; Snowling, Maggie; Buckley, Sue; Hulme, Charles

    2013-01-01

    This article reports the evaluation of a 6-week programme of teaching designed to support the development of phoneme blending skills in children with Down syndrome (DS). Teaching assistants (TAs) were trained to deliver the intervention to individual children in daily 10-15-minute sessions, within a broader context of reading and language…

  18. PREPARATION OF CARBON NANOFIBERS BY POLYMER BLEND TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.

  19. Using Blended Learning in Developing Student Teachers Teaching Skills

    Science.gov (United States)

    Isman, Aytekin; Abanmy, Fahad AbdulAziz; Hussein, Hisham Barakat; Al Saadany, Mohammed Abdelrahman

    2012-01-01

    The research aims to determine the effectiveness of using blended learning Approach in developing student teachers teaching skills, and defining teaching skills that confront students of teachers college at King Saud University need it. The research uses the Quasi- Experimental approach, with four experimental groups (Mathematics (21)--Science…

  20. Investigation on Water Jet Treated Polyester/cotton Blended Cambric

    Institute of Scientific and Technical Information of China (English)

    黄故

    2004-01-01

    Analytical examination was made to ascertain the effect of the high pressure water flow on the fabric properties.Polyester/cotton blended cambric was spurted by high pressure water flow. Fabric properties such as handle,thickness, tensile strength , stiffness and air permeability after the water treatment were investigated.

  1. A Blended Approach to Canadian First Nations Education

    Science.gov (United States)

    Sacher, Martin; Sacher, Mavis; Vaughan, Norman

    2014-01-01

    The purpose of this research study was to investigate if and how a blended approach to Canadian First Nations education could be used to foster student engagement and success. The study examined the SCcyber E-Learning Community program (2012) through the lens of the "Seven Principles of Effective Teaching" (Chickering & Gamson,…

  2. Long fiber reinforcement of polypropylene/polystyrene blends

    NARCIS (Netherlands)

    Inberg, J.P.F.; Hunse, P.H.; Gaymans, R.J.

    1999-01-01

    The recycling of inseparable polymer mixtures usually results in blends with poor mechanical properties. A mixture of PP and PS was taken as a model compound for a recyclate. The effect of adding glass fibers to a mixture of PP/PS (70/30) was studied, with special attention to long glass fiber reinf

  3. Biodegradation of diesel/biodiesel blends in saturated sand microcosms

    DEFF Research Database (Denmark)

    Lisiecki, Piotr; Chrzanowski, Łukasz; Szulc, Alicja

    2014-01-01

    The aim of the study was to evaluate the biodegradation extent of both aromatic and aliphatic hydrocarbon fractions in saturated sandy microcosm spiked with diesel/biodiesel blends (D, B10, B20, B30, B40, B50, B60, B70, B80, B90 and B100, where D is commercial petroleum diesel fuel and B is comme......The aim of the study was to evaluate the biodegradation extent of both aromatic and aliphatic hydrocarbon fractions in saturated sandy microcosm spiked with diesel/biodiesel blends (D, B10, B20, B30, B40, B50, B60, B70, B80, B90 and B100, where D is commercial petroleum diesel fuel and B...... is commercial biodiesel blend) augmented with a bacterial consortium of petroleum degraders. The biodegradation kinetics for blends were evaluated based on measuring the amount of emitted CO2 after 578 days. Subsequently, the residual aromatic and aliphatic fractions were separated and determined by employing...... GC-FID and GC _ GC–TOF-MS. Additionally, the influence of biodiesel-amendment on the community dynamics was assessed based on the results of real-time PCR analyzes. Our results suggest that the biodegradation extents of both aliphatic and aromatic hydrocarbon were uninfluenced by the addition...

  4. A Pedagogical Model for Science Education through Blended Learning

    NARCIS (Netherlands)

    Bidarra, José; Rusman, Ellen

    2015-01-01

    This paper proposes a framework to support science education through blended learning, based on a participatory and interactive approach supported by ICT-based tools, called Science Learning Activities Model (SLAM). The study constitutes a work in progress and started as a response to complex societ

  5. Blended Learning in Distance Education: Sri Lankan Perspective

    Science.gov (United States)

    Liyanagunawardena, T. R.; Adams, A. A.; Rassool, N.; Williams, S. A.

    2014-01-01

    The purpose of this paper is to explore the implementation of online learning in distance educational delivery at Yellow Fields University (pseudonymous) in Sri Lanka. The implementation of online distance education at the University included the use of blended learning. The policy initiative to introduce online for distance education in Sri Lanka…

  6. Mechanisms of Morphology Development and Control in Polymer- Polymer Blends

    Science.gov (United States)

    Macosko, Christopher W.

    1998-03-01

    Polymer-polymer blends continue to be the most important method for achieving optimization of properties in plastics products. Over 30 percent of all plastics are blends. While miscible blends generally give average properties between the components, immiscible blends offer synergistic possibilities such as high modulus with high toughness; high flow with high impact strength or diffusion barriers with good mechanical properties and low cost. The key to performance of these immiscible blends is their morphology. There are several important types of morphology which can lead to valuable property improvement: emulsion - small polymer spheres well dispersed in a polymer matrix. double emulsion - spheres inside spheres which are dispersed in another matrix. microlayer - thin, parallel layers of one polymer in a matrix. cocontinuous - two (or more) continuous, interpenetrating polymer phases. To be economical it is desirable to create these morphologies via melt mixing of powder or pellets in conventional compounding equipment. The melting stage during compounding is very important for morphology development. This presentation will demonstrate the role of melting or softening of each phase as well as their viscosity, elasticity and interfacial tension in morphology development. Interfacial modification with premade block copolymers or reactively formed copolymers can greatly alter morphology formation and stability. Experimental results will be presented which quantify the role of these additives. References to recent work in this area by our group are listed below: DeBrule, M. B., L. Levitt and C.W. Macosko, "The Rheology and Morphology of Layered Polymer Melts in Shear," Soc. Plastics Eng. Tech Papers (ANTEC), 84-89 (1996). Guegan, P., C. W. Macosko, T. Ishizone, A. Hirao and S. Nakahama, "Kinetics of Chain Coupling at Melt Interfaces, Macromol. 27, 4993-4997 (1994). Lee, M. S., T.P. Lodge, and C. W. Macosko, "Can Random Copolymers Serve as Effective Polymeric

  7. Norwegian Nurses’ Experiences with Blended Learning: An Evaluation Study

    Directory of Open Access Journals (Sweden)

    Edda Johansen

    2012-04-01

    Full Text Available An increasing number of nurses undertake continuing education via information and communication technologies. Development of best practice, based on students’ own experiences, is vital in order to create the most effective learning environment. This paper describes the challenges to and facilitators of learning for a group of Norwegian nurses enrolled in a postgraduate course in wound management delivered by blended learning, which combines face-to-face and online components. Data was gathered through a focus group interview and inductive content analysis was used to identify themes emerging from the data. A number of both personal and academic facilitators, and challenges impacted on these adult learners. Technical and academic problems combined with a lack of time created a steep learning curve for these adult students. Valuable feedback, IT support at home and an increased competence eventually gave them a foundation for lifelong learning. Blended learning is an important way to offer postgraduate courses to give adults access to continuing educational programmes independent of geographical location. Both academic and personal challenges and facilitators should be taken into account when educators design blended learning courses in order to facilitate an effective learning environment for adults through the best blend of face-to-face and online learning.

  8. Physicochemical, microbiological and sensory evaluation of a bioactive food blend

    Directory of Open Access Journals (Sweden)

    Rosângela dos Santos Ferreira

    2014-09-01

    Full Text Available The potential of functional foods to decrease the risks of chronic non-communicable diseases has motivated the development of products with beneficial effects on fat and carbohydrate metabolism. The present study aimed at analyzing the physicochemical, microbiological, and sensory properties of a bioactive food blend developed to help the nutritional therapy provided to hypolipidemic and hyperglycemic patients with HIV/AIDS treated with antiretroviral therapy. The food blend was evaluated for moisture, protein, carbohydrate, fats, fixed mineral residue, total fiber content, and fatty acid composition, according to the standards established by the Instituto Adolfo Lutz. Food safety was assessed by microbiological analyses for Bacillus cereus, Salmonella spp, and coliforms. Sensory acceptance and intention to purchase were also evaluated. The food blend showed good nutritional potential, with low atherogenicity and thrombogenicity indexes, good macronutrient balance, and high energy value. The adoption of Good Manufacturing Practices (GMP resulted in a product suitable for consumption. With respect to sensory aspects, the food blend showed satisfactory indexes of acceptability and promising marketing potential.

  9. Process improvement for regulatory analyses of custom-blend fertilizers.

    Science.gov (United States)

    Wegner, Keith A

    2014-01-01

    Chemical testing of custom-blend fertilizers is essential to ensure that the products meet the formulation requirements. For purposes of proper crop nutrition and consumer protection, regulatory oversight promotes compliance and particular attention to blending and formulation specifications. Analyses of custom-blend fertilizer products must be performed and reported within a very narrow window in order to be effective. The Colorado Department of Agriculture's Biochemistry Laboratory is an ISO 17025 accredited facility and conducts analyses of custom-blend fertilizer products primarily during the spring planting season. Using the Lean Six Sigma (LSS) process, the Biochemistry Laboratory has reduced turnaround times from as much as 45 days to as little as 3 days. The LSS methodology focuses on waste reduction through identifying: non-value-added steps, unneeded process reviews, optimization of screening and confirmatory analyses, equipment utilization, nonessential reporting requirements, and inefficient personnel deployment. Eliminating these non-value-added activities helped the laboratory significantly shorten turnaround time and reduce costs. Key improvement elements discovered during the LSS process included: focused sample tracking, equipment redundancy, strategic supply stocking, batch size optimization, critical sample paths, elimination of nonessential QC reviews, and more efficient personnel deployment.

  10. Successively refined models for crack tip plasticity in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, KGW; Seelig, T; van der Giessen, E

    2005-01-01

    This paper is concerned with a comparative study of different, partly complementary micromechanical models for crack tip plasticity in polymer-rubber blends. It is experimentally well established that interspersion of micron-scale rubber particles into a polymer matrix can lead to a significantly en

  11. Photoluminescence of conjugated polymer blends at the nanoscale

    NARCIS (Netherlands)

    Jarzab, D.; Lu, M.; Nicolai, H.T.; Blom, P.W.M.; Loi, M.A.

    2011-01-01

    Here we report on a combined photoluminescence and morphological study of a polymer-polymer blend composed of a copolymer of derivatives of polyspirobifluorene and polyfluorene (PBFF) and a derivative of polyphenylene vinylene (MDMO-PPV). Evidence of partial Förster energy transfer from PBFF to MDMO

  12. Preparing Language Teachers for Blended Teaching of Summary Writing

    Science.gov (United States)

    Yang, Yu-Fen

    2014-01-01

    Research on preparing language teachers for blended teaching of summary writing, a mix of on-site and online instruction for college students to grasp the gist of the texts, is scarce in higher education. This study examined the problems encountered and solutions proposed by six language teachers, who altogether instructed 214 college students on…

  13. Blended Instruction: The Roaring Twenties Meets Coursesites.com

    Science.gov (United States)

    Waldron, Diane L.

    2014-01-01

    The action research study described in this report outlines the design and implementation of a unit of blended instruction in a traditional high school English classroom. Twenty technical high school students in an 11th grade Honors English class engaged in a variety of internet-based activities in conjunction with traditional learning activities…

  14. Techno-Instruction or Primitivism: Blended Instruction in Algebra I

    Science.gov (United States)

    McNeely, Silvia Ann

    2014-01-01

    Integrated technology within a learning environment has become a common instructional expectation in public schools. Many school officials are embracing constructivist views that students learn best within a blended learning environment that promotes active learning by anchoring skills and concepts affiliated to real-world activities. This…

  15. COPOLYMER BLENDS OF STYRENE AND ORTHO-FLUOROSTYRENE

    NARCIS (Netherlands)

    TENBRINKE, G; KARASZ, FE

    1991-01-01

    The traditional method, using differential scanning calorimetry, to study phase behaviour in blends containing styrene and fluorinated styrene is hampered by the fact that the glass transition temperatures of fluorinated polystyrenes are almost independent of the degree of fluorination. To deal with

  16. Partitioning Behavior of Petrodiesel/Biodiesel Blends in Water

    Science.gov (United States)

    The partitioning behavior of six petrodiesel/soybean-biodiesel blends (B0, B20, B40, B60, B80, and B100, where B100 is 100% unblended biodiesel) in water was investigated at various oil loads by the 10-fold dilution method. Five fatty acid methyl esters (FAMEs), C10 - C20 n

  17. Blending Student Technology Experiences in Formal and Informal Learning

    Science.gov (United States)

    Lai, K.-W.; Khaddage, F.; Knezek, Gerald

    2013-01-01

    In this article, we discuss the importance of recognizing students' technology-enhanced informal learning experiences and develop pedagogies to connect students' formal and informal learning experiences, in order to meet the demands of the knowledge society. The Mobile-Blended Collaborative Learning model is proposed as a framework to…

  18. Teachers' experiences of teaching in a blended learning environment.

    Science.gov (United States)

    Jokinen, Pirkko; Mikkonen, Irma

    2013-11-01

    This paper considers teachers' experiences of teaching undergraduate nursing students in a blended learning environment. The basic idea of the study programme was to support students to reflect on theory and practice, and provide with access to expert and professional knowledge in real-life problem-solving and decision making. Learning was organised to support learning in and about work: students worked full-time and this provided excellent opportunities for learning both in practice, online and face-to-face sessions. The aim of the study was to describe teachers' experiences of planning and implementing teaching and learning in a blended-learning-based adult nursing programme. The research method was qualitative, and the data were collected by three focus group interviews, each with four to six participants. The data were analysed using qualitative content analysis. The results show that the blended learning environment constructed by the combination of face-to-face learning and learning in practice with technology-mediated learning creates challenges that must be taken into consideration when planning and implementing blended teaching and learning. However, it provides good opportunities to enhance students' learning in and about work. This is because such programmes support student motivation through the presence of "real-life" and their relevance to the students' own places of work. Nevertheless, teachers require knowledge of different pedagogical approaches; they need professional development support in redesigning teaching and learning.

  19. Clay platelet partition within polymer blend nanocomposite films by EFTEM.

    Science.gov (United States)

    Linares, Elisângela M; Rippel, Márcia M; Galembeck, Fernando

    2010-12-01

    Transmission electron microscopy (TEM) is the main technique used to investigate the spatial distribution of clay platelets in polymer nanocomposites, but it has not often been successfully used in polymer blend nanocomposites because the high contrast between polymer phases impairs the observation of clay platelets. This work shows that electron spectral imaging in energy-filtered TEM (EFTEM) in the low-energy-loss spectral crossover region allows the observation of platelets on a clear background. Separate polymer domains are discerned by imaging at different energy losses, above and below the crossover energy, revealing the material morphology. Three blends (natural rubber [NR]/poly(styrene-butyl acrylate) [P(S-BA)], P(S-BA)/poly(vinyl chloride) [PVC], and NR/starch) were studied in this work, showing low contrast between the polymer phases in the 40-60 eV range. In the NR/P(S-BA) and P(S-BA)/PVC blend nanocomposites, the clay platelets accumulate in the P(S-BA) phase, while in the P(S-BA)/PVC nanocomposites, clay is also found at the interfaces. In the NR/starch blend, clay concentrates at the interface, but it also penetrates the two polymer phases. These observations reveal that nanostructured soft materials can display complex morphochemical patterns that are discerned thanks to the ability of EFTEM to produce many contrast patterns for the same sample.

  20. Design Framework for an Adaptive MOOC Enhanced by Blended Learning

    DEFF Research Database (Denmark)

    Gynther, Karsten

    2016-01-01

    The research project has developed a design framework for an adaptive MOOC that complements the MOOC format with blended learning. The design framework consists of a design model and a series of learning design principles which can be used to design in-service courses for teacher professional...

  1. Transforming K-12 Rural Education through Blended Learning: Teacher Perspectives

    Science.gov (United States)

    Kellerer, Paula; Kellerer, Eric; Werth, Eric; Werth, Lori; Montgomery, Danielle; Clyde, Rozella; Cozart, Joe; Creach, Laura; Hibbard, Laura; LaFrance, Jason; Rupp, Nadine; Walker, Niki; Carter, Theresa; Kennedy, Kathryn

    2014-01-01

    A qualitative study exploring rural teacher perspectives on the impact of blended learning on students and teachers was conducted in Idaho during the Fall of 2013. Researchers from Northwest Nazarene University's DOCEO Center in partnership with Idaho Digital Learning Academy (IDLA) and the International Association for K-12 Online Learning…

  2. Blended Learning: Instructional Design Strategies for Maximizing Impact

    Science.gov (United States)

    Adams, Jean

    2013-01-01

    Although e-learning has improved in quality, reach and learning impact over the past decade, it can be argued that it has not yet lived up to its potential to transform workplace learning. In the drive to increase effectiveness, interest has grown in blended learning, an instructional strategy that combines the use of web-technologies with more…

  3. Practical Applications and Experiences in K-20 Blended Learning Environments

    Science.gov (United States)

    Kyei-Blankson, Lydia, Ed.; Ntuli, Esther, Ed.

    2014-01-01

    Learning environments continue to change considerably and is no longer confined to the face-to-face classroom setting. As learning options have evolved, educators must adopt a variety of pedagogical strategies and innovative technologies to enable learning. "Practical Applications and Experiences in K-20 Blended Learning Environments"…

  4. iNACOL Blended Learning Teacher Competency Framework

    Science.gov (United States)

    Powell, Allison; Rabbitt, Beth; Kennedy, Kathryn

    2014-01-01

    In recent years there has been a dramatic rise in interest and early adoption of blended learning to improve the educational experiences of students. A great amount of work has been done to codify approaches, with tools and resources emphasizing the structural components of new models, such as the configuration of physical learning space, use of…

  5. Blended Learning in Higher Education: Three Different Design Approaches

    Science.gov (United States)

    Alammary, Ali; Sheard, Judy; Carbone, Angela

    2014-01-01

    Blended learning has been growing in popularity as it has proved to be an effective approach for accommodating an increasingly diverse student population whilst adding value to the learning environment through incorporation of online teaching resources. Despite this growing interest, there is ongoing debate about the definition of the concept of…

  6. 27 CFR 24.213 - Heavy bodied blending wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Heavy bodied blending wine. 24.213 Section 24.213 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... fruit or for removal upon payment of tax, not for sale or consumption as beverage wine. Upon...

  7. 27 CFR 24.214 - Spanish type blending sherry.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Spanish type blending sherry. 24.214 Section 24.214 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... tax, not for sale or consumption as beverage wine. Wine of a high solids content and dark in...

  8. A Pedagogical Model for Science Education through Blended Learning

    NARCIS (Netherlands)

    Bidarra, Jose; Rusman, Ellen

    2015-01-01

    This presentation proposes a framework to support science education through blended learning, based on a participatory and interactive approach supported by ICT-­‐based tools, called Science Learning Activities Model (SLAM). The study constitutes a work in progress and started as a response to compl

  9. Blended Families in Conflict: Essentials a Pastor Must Know

    Science.gov (United States)

    Perry, William J.

    2013-01-01

    The rise of blended families is becoming a prevalent dynamic in our society. According to the United States Census Bureau: American Community Survey, 2009 report, the U.S. is approaching a fifty percent divorce rate. Fifty percent will remarry within three and half years of their divorce. Of these, sixty-five percent will have children from their…

  10. Supporting Blended-Learning: Tool Requirements and Solutions with OWLish

    Science.gov (United States)

    Álvarez, Ainhoa; Martín, Maite; Fernández-Castro, Isabel; Urretavizcaya, Maite

    2016-01-01

    Currently, most of the educational approaches applied to higher education combine face-to-face (F2F) and computer-mediated instruction in a Blended-Learning (B-Learning) approach. One of the main challenges of these approaches is fully integrating the traditional brick-and-mortar classes with online learning environments in an efficient and…

  11. Coal blend combustion: fusibility ranking from mineral matter composition

    Energy Technology Data Exchange (ETDEWEB)

    C. Goni; S. Helle; X. Garcia; A. Gordon; R. Parra; U. Kelm; R. Jimenez; G. Alfaro [Universidad de Concepcion, Concepcion (Chile). Departamento de Ingenieria Metalurgica, Instituto de Geologia Economica Aplicada (GEA)

    2003-10-01

    Although coal blends are increasingly utilized at power plants, ash slagging propensity is a non-additive property of the pure coals and hence difficult to predict. Coal ash tendency to slag is related to its bulk chemistry and ash fusion temperatures, and the present study aims to compare the results obtained from thermodynamic simulation with characterization of samples obtained as outcomes of plant-based coal-blend combustion trials at three utilities located in the Centre and North of Chile. Pulverized coal and plant residues samples from five families of binary blends tested in an experimental program were characterized for chemistry, mineralogy and maceral composition. The slagging was evaluated by determination of fusion curves using the MTDATA software and NPLOX3 database for the main coal ash oxides. The ranking obtained was approximately the same as obtained from carbon in the fly ashes and from plant residues observations. The thermodynamic modeling was a valid option to predict the fusibility during the combustion of blends. 16 refs., 7 figs., 1 tab.

  12. A family of quasi-cubic blended splines and applications

    Institute of Scientific and Technical Information of China (English)

    SU Ben-yue; TAN Jie-qing

    2006-01-01

    A class of quasi-cubic B-spline base functions by trigonometric polynomials are established which inherit properties similar to those of cubic B-spline bases. The corresponding curves with a shape parameter α, defined by the introduced base functions, include the B-spline curves and can approximate the B-spline curves from both sides. The curves can be adjusted easily by using the shape parameter α, where dpi(α,t) is linear with respect to dα for the fixed t. With the shape parameter chosen properly,the defined curves can be used to precisely represent straight line segments, parabola segments, circular arcs and some transcendental curves, and the corresponding tensor product surfaces can also represent spherical surfaces, cylindrical surfaces and some transcendental surfaces exactly. By abandoning positive property, this paper proposes a new C2 continuous blended interpolation spline based on piecewise trigonometric polynomials associated with a sequence of local parameters. Illustration showed that the curves and surfaces constructed by the blended spline can be adjusted easily and freely. The blended interpolation spline curves can be shape-preserving with proper local parameters since these local parameters can be considered to be the magnification ratio to the length of tangent vectors at the interpolating points. The idea is extended to produce blended spline surfaces.

  13. BLOCK BASED NEWTON-LIKE BLENDING OSCULATORY RATIONAL INTERPOLATION

    Institute of Scientific and Technical Information of China (English)

    Shuo Tang; Le Zou; Chensheng Li

    2010-01-01

    With Newton's interpolating formula,we construct a kind of block based Newton-like blending osculatory interpolation.The interpolation provides us many flexible interpolation schemes for choices which include the expansive Newton's polynomial interpolation as its special case.A bivariate analogy is also discussed and numerical examples are given to show the effectiveness of the interpolation.

  14. Bivariate Blending Thiele-Werner's Osculatory Rational Interpolation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Both the expansive Newton's interpolating polynomial and the Thiele-Werner's interpolation are used to construct a kind of bivariate blending Thiele-Werner's osculatory rational interpolation. A recursive algorithm and its characteristic properties are given. An error estimation is obtained and a numerical example is illustrated.

  15. Charge generation and recombination in PCDTBT:PCBM photovoltaic blends

    Energy Technology Data Exchange (ETDEWEB)

    Etzold, Fabian; Howard, Ian; Mauer, Ralf; Meister, Michael; Laquai, Frederic [Max-Planck-Institute for Polymer Research, Mainz (Germany)

    2011-07-01

    Low-bandgap donor-acceptor copolymers have recently demonstrated their potential in bulk heterojunction organic solar cells. Among them, poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) blended with fullerene derivatives proved to be very efficient, yielding power conversion efficiencies in excess of 3 % even without postproduction annealing, which is typically applied to polythiophene:fullerene blends. We investigate exciton dynamics in pristine PCDTBT and charge carrier dynamics in as-cast and annealed blends with [6,6]-phenyl C{sub 61} butyric acid methyl ester (PCBM) by transient absorption and time-resolved photoluminescence spectroscopy. We find that in PCDTBT:PCBM blends a large fraction of excitons undergoes ultrafast generation of free charge carriers as previously observed for other material systems including P3HT:PCBM. However, a fraction of interfacial charge transfer states is also created, which recombine geminately with a lifetime of 2.5 ns. By monitoring the recombination dynamics over the previously unobserved time range from 1 ns to 1 ms, we conclude that the device efficiency must be limited by geminate recombination and charge extraction.

  16. Virtual reality training versus blended learning of laparoscopic cholecystectomy

    DEFF Research Database (Denmark)

    Nickel, Felix; Brzoska, Julia Anja; Gondan, Matthias;

    2015-01-01

    Objective: This study compared virtual reality (VR) training with low cost blended learning (BL) in a structured training program. Background: Training of laparoscopic skills outside the operating room is mandatory to reduce operative times and risks. Methods: Laparoscopy-naïve medical students...

  17. Effects of Blended Instructional Models on Math Performance

    Science.gov (United States)

    Bottge, Brian A.; Ma, Xin; Gassaway, Linda; Toland, Michael D.; Butler, Mark; Cho, Sun-Joo

    2014-01-01

    A pretest-posttest cluster-randomized trial involving 31 middle schools and 335 students with disabilities tested the effects of combining explicit and anchored instruction on fraction computation and problem solving. Results of standardized and researcher-developed tests showed that students who were taught with the blended units outscored…

  18. Blended Learning and Teaching Writing: A Teacher Action Research Project

    Science.gov (United States)

    Camahalan, Faye Marsha G.; Ruley, Andrea G.

    2014-01-01

    This teacher research project focused on utilizing blended learning to teach writing to middle school students. The intervention was designed to fit into individual lessons needed to improve students' writing skills with the main focus on sentence structure. Sixteen (16) 7th grade students were assessed with a writing sample applying the new…

  19. From Blended to Online Learning: Components of the Gap

    Science.gov (United States)

    Santally, Mohammad Issack

    2005-01-01

    At the University of Mauritius, blended learning is defined as the application of technology to support a range of teaching and learning activities in courses that are mainly given to full-time undergraduate students on campus and part-time mature students on postgraduate programmes. This article reports the observations of two studies that were…

  20. STUDY ON THE BLENDS OF NYLON 66 AND LIQUID CRYSTALLINE POLYESTERS

    Institute of Scientific and Technical Information of China (English)

    Zhang Shufan; Ren Jinghong

    1991-01-01

    Blends of polyamide (Nylon 66 ) with two different kinds of liquid crystalline polyesters were studied in all the composition range. Homogeneous samples were obtained by coprecipitation from 2wt%. solution of blends. The thermal properties, crystallinity and morphology of these blends were studied by using DSC, polarizing microscopy, and scanning electron microscopy. The phase transition and morphology of the blends are markedlyinfluenced by the composition of liquid crystalline polyesters. The mechanical behaviour of PHB/HNA-Nylon 66 blend was improved .although polyamide (Nylon 66)with the liquid crystalline polyesters were incompatible, but a rather strong interaction between the polymers did exist.

  1. Quantification of Coffea arabica and Coffea canephora var. robusta in roasted and ground coffee blends.

    Science.gov (United States)

    Cagliani, Laura Ruth; Pellegrino, Gloria; Giugno, Graziella; Consonni, Roberto

    2013-03-15

    This study reports direct quantification of arabica in roasted and ground coffee blends of Coffea arabica and Coffea canephora var. robusta. (1)H-NMR analysis of water extracts of coffee blends were combined with multivariate statistical analysis to obtain an OPLS model with high predictive capability. This approach allowed to evaluate the composition of coffee blends of unknown arabica and robusta content, on the basis of multiple chemical components. Differences in geographical origin of the analyzed samples did not affected the compositional determination of coffee blends. This approach represents a valid tool in authentication procedures of arabica and robusta blends of roasted and ground coffee.

  2. Morphology Formation in PC/ABS Blends during Thermal Processing and the Effect of the Viscosity Ratio of Blend Partners

    Directory of Open Access Journals (Sweden)

    Stefanie Bärwinkel

    2016-08-01

    Full Text Available Morphology formation during compounding, as well as injection molding of blends containing 60 wt % polycarbonate (PC and 40 wt % polybutadiene rubber-modified styrene-acrylonitrile copolymers (ABS, has been investigated by transmission electron microscopy (TEM. Profiles of the blend morphology have been recorded in injection-molded specimens and significant morphology gradients observed between their skin and core. A <10 µm thick surface layer with strongly dispersed and elongated nano-scale (streak-like styrene acrylonitrile (SAN phases and well-dispersed, isolated SAN-grafted polybutadiene rubber particles is followed by a 50–150 µm thick skin layer in which polymer morphology is characterized by lamellar SAN/ABS phases. Thickness of these lamellae increases with the distance from the specimen’s surface. In the core of the specimens the SAN-grafted polybutadiene rubber particles are exclusively present within the SAN phases, which exhibit a much coarser and less oriented, dispersed morphology compared to the skin. The effects of the viscosity of the SAN in the PC/ABS blends on phase morphologies and correlations with fracture mechanics in tensile and impact tests were investigated, including scanning electron microscopy (SEM assessment of the fracture surfaces. A model explaining the mechanisms of morphology formation during injection molding of PC/ABS blends is discussed.

  3. Rheological Behavior of Immiscible PS/LDPE Blends: A Comparative Study of the Palierne Emulsion Model

    Directory of Open Access Journals (Sweden)

    Chatchai KUNYAWUT

    2015-02-01

    Full Text Available The rheological behavior of polystyrene (PS/low density polyethylene (LDPE blends have been investigated. Blends with 10, 20 and 30 wt% LDPE were prepared using a co-rotating twin-screw extruder at a melt mixing temperature of 180°C. SEM micrographs revealed that all blends exhibited droplet-type dispersion morphology. Rheological measurements were performed at the same temperature as the mixing temperature. The complex viscosity of the blends laid between those of the PS and the LDPE and decreased with increasing LDPE concentration. The plots of tand of blends with 10 and 20 wt% LDPE suggested that the elasticity of these blends was comparable to that of the pure PS. By contrast, the elasticity behavior of the blend with 30 wt% LDPE was shown to be similar to that of LDPE. Palierne model predictions were in very good agreement with the experimental data for the blends having 10 and 20 wt% LDPE. For the 30 wt% LDPE blend, agreement with the prediction and the experimental data was not as good. Within the frequency range of the rheological measurements, the second plateau at low frequency which results from an increase of the elasticity was not observed in any of the blends studied. This is expected to be due to the long relaxation times of the relatively large LDPE droplets of these blends.

  4. Characterization of banana, potato, and rice starch blends for their physicochemical and pasting properties

    Directory of Open Access Journals (Sweden)

    Ritika B. Yadav

    2016-12-01

    Full Text Available The properties of blends of banana, potato, and rice starches were studied to assess their suitability as an alternate for chemically modified starches. The blends of banana, potato, and rice starches were prepared in the respective ratio of 1:3:2, 3:2:1, and 2:1:3. The blend with higher proportion of banana and rice starches (BPR-213 showed highest water absorption capacity and oil absorption capacity. The blend with higher proportion of banana starch (BPR-321 showed highest swelling power at 95°C but lowest water solubility at 95°C among other starch blends. The blend made with higher amount of potato starch (BPR-132 had significantly higher paste clarity than other blends (p < 0.05. The potato starch had significantly higher least gelation concentration than all other starches and their blends (p < 0.05. The banana starch and blend with highest proportion of banana starch (BPR-321 showed significantly lesser percent syneresis and thus highest freeze–thaw stability. Potato starch as well as it blends with greater amount of potato starch (BPR-132 showed highest value for peak viscosity, hot paste viscosity, and final viscosity than other blends.

  5. Degradation assessment of natural weathering on low density polyethylene/thermoplastic soya spent powder blends

    Science.gov (United States)

    Nuradibah, M. A.; Sam, S. T.; Noriman, N. Z.; Ragunathan, S.; Ismail, H.

    2015-07-01

    Soya spent powder was blended with low density polyethylene (LDPE) ranging from 5-25 wt%. Glycerol was added to soya spent powder (SSP) for preparation of thermoplastic soya spent powder (TSSP). Then, the blends were exposed to natural weathering for 6 months. The susceptibility of the LDPE/soya spent powder blends based on its tensile, morphological properties and structural changes was measured every three months. The tensile strength of LDPE/TSSP blends after 6 months of weathering was the lowest compared to the other blends whereas LDPE/SSP blends after 6 months of weathering demonstrated the lowest elongation at break (Eb). Large pore can be seen on the surface of 25 wt% of LDPE/SSP blends.

  6. Design of tailor-made chemical blend using a decomposition-based computer-aided approach

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza; Gernaey, Krist; Manan, Z.A.;

    2011-01-01

    Computer aided techniques form an efficient approach to solve chemical product design problems such as the design of blended liquid products (chemical blending). In chemical blending, one tries to find the best candidate, which satisfies the product targets defined in terms of desired product...... the desired product attributes. Alternatively, rigorous modeling could also be used in this final step. In other words, the candidates are quickly generated and screened until a small number is left for final selection and evaluation by experiments and/or rigorous modeling. This paper presents a design...... methodology for blended liquid products that identifies a set of feasible chemical blends. The blend design problem is formulated as a Mixed Integer Nonlinear Programming (MINLP) model where the objective is to find the optimal blended gasoline or diesel product subject to types of chemicals...

  7. Phase Behavior, Thermal Stability and Rheological Properties of PPEK/PC Blends

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Phase behavior, thermal stability and rheological properties of the blends of poly(phthalazinone ether ketone) (PPEK)with bisphenol-A polycarbonate (PC) prepared by solution coprecipitation were studied using differential scanning calorimetry (DSC), Frourier-Transform IR spectroscopy (FT-IR), thermogravimetric analysis (TGA) and capillary rheometer. The DSC results indicated that PPEK/PC blends are almost immiscible in full compositions. FT-IR investigation showed that there were no apparent specific interactions between the constituent polymers. The blends keep excellent thermal stability and the addition of PC degrades the thermal stability of blends to some degree. The thermal degradation processes of the blends are much similar to that of PC. The studies on rheological properties of blends show that blending PPEK with PC is beneficial to reducing the melt viscosity and improving the appearance of PPEK.

  8. Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

    Science.gov (United States)

    Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

    2016-11-01

    Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

  9. Review Of Rheology Models For Hanford Waste Blending

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.; Stone, M.

    2013-09-26

    The area of rheological property prediction was identified as a technology need in the Hanford Tank Waste - waste feed acceptance initiative area during a series of technical meetings among the national laboratories, Department of Energy-Office of River Protection, and Hanford site contractors. Meacham et al. delivered a technical report in June 2012, RPP-RPT-51652 ''One System Evaluation of Waste Transferred to the Waste Treatment Plant'' that included estimating of single shell tank waste Bingham plastic rheological model constants along with a discussion of the issues inherent in predicting the rheological properties of blended wastes. This report was selected as the basis for moving forward during the technical meetings. The report does not provide an equation for predicting rheological properties of blended waste slurries. The attached technical report gives an independent review of the provided Hanford rheological data, Hanford rheological models for single tank wastes, and Hanford rheology after blending provided in the Meacham report. The attached report also compares Hanford to SRS waste rheology and discusses some SRS rheological model equations for single tank wastes, as well as discussing SRS experience with the blending of waste sludges with aqueous material, other waste sludges, and frit slurries. Some observations of note: Savannah River Site (SRS) waste samples from slurried tanks typically have yield stress >1 Pa at 10 wt.% undissolved solids (UDS), while core samples largely have little or no yield stress at 10 wt.% UDS. This could be due to how the waste has been processed, stored, retrieved, and sampled or simply in the differences in the speciation of the wastes. The equations described in Meacham's report are not recommended for extrapolation to wt.% UDS beyond the available data for several reasons; weak technical basis, insufficient data, and large data scatter. When limited data are available, for example two to

  10. Effect of Blending Ratio on Modal Fiber Cotton Blended Yarn Quality%混纺比对Modal纤维棉混纺纱性能的影响

    Institute of Scientific and Technical Information of China (English)

    严瑛

    2012-01-01

    探讨混纺比对Modal纤维棉混纺纱性能的影响.选取Modal纤维与棉为原料,分别纺制14.5 tex的纯棉精梳纱、纯Modal纱以及Modal与棉混纺比分别为20/80、30/70、40/60、50/50的混纺精梳纱,并通过对比试验,分析了混纺比对成纱强伸性能、条干、毛羽的影响.结果表明:从提高混纺纱断裂强度考虑,混纺比选择50/50比较适宜;Modal纤维的含量在40%左右时,成纱条干较好;混纺比为40/60或50/50左右时,成纱毛羽数较低.%Effect of blending ratio on Modal fiber cotton blended yarn quality was discussed. Modal fiber and cotton were selected as raw material,pure cotton 14. 5 tex combed yarn was spun,pure Modal 14. 5 tex yarn was spun,Modal cotton blended yarns were spun as well,the blending ratio was 20/80,30/70,40/60 and 50/50- Through contrast and test,effect of blending ratio on yarn strength and elongation,evenness and hairiness were analyzed. The result shows when adopting the blending ratio of 50/50 breaking intensity of the blended yarn is better,when adopt the blending ratio of 40/60 evenness of the blended yarn is better, when adopt the blending ratio of 50/50 or 40/60 hairiness of the blended yarns are better.

  11. Molecular composites and polymer blends containing ionic polymers

    Science.gov (United States)

    Tsou, Li-Chun

    1997-11-01

    Polymer blends are generally immiscible due to the unfavorable thermodynamics of mixing. By the introduction of ion-dipole interaction, mechanical properties of the PPTA anion/polar polymers (such as PVP, PEO and PPrO) molecular composites have been investigated in relation to their miscibility and microstructural morphology. Optical clarity observed in the glassy PPTA anion/PVP system suggest the presence of miscibility, since the refractive indices between the two components are quite different, nsb{PVP} = 1.509 and nsb{PPTA} = 1.644. In general, the difference greater than 0.01 is sufficient to make blends opaque. DSC measurements, showing a composition dependent Tsb{g} and a melting temperature depression, also indicate the miscibility achieved at the molecular level, about 50-100 A. By using the Hoffman-Weeks plot, a negative Flory-Huggins interaction parameter, chi = -1.10, is obtained for the PPTA anion/PEO molecular composites. An irregular spherulitic pattern and a reduced crystal size suggest that PPTA anion is intimately mixed with the amorphous PEO, both inter- and intra-spherulitically. Molecular composites exhibit not only an enhanced tensile strength and modulus, but also a greater fracture toughness, Ksb{IC}, e.g., an 80% increase at a 2 wt% PPTA anion addition. An enhanced tensile strength associated with a reduced crystallinity suggests that PPTA anion is the major contributor to the superior tensile properties instead of the crystalline phase. Upon addition of PPTA anion to PPrO, a slower relaxation rate and a better thermal stability are observed. Significant enhancement is found when the monovalent K salt is replaced with a divalent Ca salt. The molecular reinforcement achieved via ion-dipole interactions is more effective than the rigid filler effect obtained in the non-ionic PPTA/PPrO blend: e.g., a modulus enhancement of 814% vs. 286%, as compared with the value for PPrO. Two phase systems with microphase separation are developed since many

  12. THE HANDBOOK OF BLENDED LEARNING:Global Perspectives, Local Designs

    Directory of Open Access Journals (Sweden)

    Reviewed by Alev ATES

    2009-10-01

    Full Text Available THE HANDBOOK OF BLENDED LEARNING:Global Perspectives, Local Designs Curtis J. Bonk (ed. and Charles R. Graham (ed., Jay Cross (Foreword,Micheal G. Moore Foreword ISBN: 978-0-7879-7758-0 Publisher: John Wiley & Sons, Inc. Pfeiffer Pages: 624 March 2006.Reviewed by Alev ATESPhD Student at Curriculum and Instruction,Lecturer at Computer Education and Instructional Technologies,Faculty of Education, Ege University, Izmir, TURKEYBlended learning or blended e-learning sounds like aconfusing term at first since it is relatively a new term fortoday‘s instructors. However, Moore reports that it can betraced as far back as the 1920s which was called ―supervisedcorrespondence study‖. For clarification of the term ―blendedlearning‖ and informing the instructors about its commonpractices worldwide, the book provides readers a comprehensive resource about blended learning. It aims to raise awareness of adopting BL from institutional perspectives of many chapter authors from Australia, Korea, Malaysia, the UK, Canada and South Africa who are distinguished people mostly in instructional technology era. With this book, I guess the editors aim at both showing the big picture at macro level and present micro level examples which provide details of blended learning applications among their strengths and weaknesses. As introduced in the book, one ofthe editors Curtis J. Bonk, a former corporate controller and CPA, is now professor of educational psychology as well as instructional systems technology at Indiana University; the other editor Charles R. Graham is an assistant professor of instructionalpsychology and technology at Brigham Young University with a focus on technologymediated teaching and learning.The book is of eight parts including 39 chapters besides two forewords. Therefore, theorganization of this review is considered to take a holistic view for each parts while emphasizing the original and/or impressive aspects that chapter authors provided

  13. A Comparative Characteristic Study of Jatropha and Cardanol Biodiesel Blends

    Science.gov (United States)

    Pugazhenthi, R.; Chandrasekaran, M.; Muthuraman, R. K.; Vivek, P.; Parthiban, A.

    2017-03-01

    The demand in fuel needs and the depleting fossil fuels raised the need towards bio-fuels. The emerging trend in research field is highly focused on biodiesel production and their characteristic analysis. Since pollution is a major threat to the environment, emission parameter analyses are much important to be concentrated. As the entire world contains plenty of biofuels, it is necessary to explore them for its efficiency and analyze their parameters. In this experimental work jatropha and cashew nut shell biodiesel (Cardanol) was extracted and they were blended with diesel. The characteristics of jatropha and cardanol biodiesel were studied in the DI diesel engine by varying the load at the same speed. In brief, this experimental analysis is carried out to compare the emission characteristics between Jatropha biodiesel at 20% (B20) and 40% (B40) and Cardanol biodiesel blends at 20% (C20) and 40% (C40).

  14. Shaking and Blending Effect on Microalgae Concentrates Size

    Directory of Open Access Journals (Sweden)

    LUDI PARWADANI AJI

    2012-03-01

    Full Text Available Microalgae concentrates (paste can be used as an alternative feed to replace live microalgae for aquaculture due to its nutritional value and convenience. However, the clumping of cells and negative buoyancy of algae concentrate can affect bivalve culture as bivalves only capture particles in suspension and ingest a certain size range of particles. This study investigated the effect of shaking and blending treatments on the preparation of food suspensions prepared from algae concentrates (Isochrysis and Pavlova. The results indicated that the higher the shaking time (5, 10, and 15 times or blending time (10, 30, and 60 seconds, the smaller was the diameter of the resulting algae particles. Moreover, the greater the volume of algae concentrate used in preparation, the larger the diameter of algae particles produced. Shaking may be the best option because it is cheaper and simpler. However, all the treatments provided a suitable particle size range for ingestion by bivalves.

  15. Modeling and Optimization of Cement Raw Materials Blending Process

    Directory of Open Access Journals (Sweden)

    Xianhong Li

    2012-01-01

    Full Text Available This paper focuses on modelling and solving the ingredient ratio optimization problem in cement raw material blending process. A general nonlinear time-varying (G-NLTV model is established for cement raw material blending process via considering chemical composition, feed flow fluctuation, and various craft and production constraints. Different objective functions are presented to acquire optimal ingredient ratios under various production requirements. The ingredient ratio optimization problem is transformed into discrete-time single objective or multiple objectives rolling nonlinear constraint optimization problem. A framework of grid interior point method is presented to solve the rolling nonlinear constraint optimization problem. Based on MATLAB-GUI platform, the corresponding ingredient ratio software is devised to obtain optimal ingredient ratio. Finally, several numerical examples are presented to study and solve ingredient ratio optimization problems.

  16. On the Factors Influencing New Ventures’ Blended Values

    DEFF Research Database (Denmark)

    Giones, Ferran; Ungerer, Christina; Baltes, Guido

    Mullen 2007). These so-called hybrid organizations try to be congruent with their blended values, despite being under external pressure in the process of maturing the new venture (Mcmullen & Warnick 2016). This research explores not only the initial motivations of the entrepreneur as potential influence...... on the ventures’ blended values, but also the source of finance. A dataset of 4,125 early-stage ventures (Entrepreneurship Database Program; Emory University) has been explored to gain insights into how entrepreneurs' motives and external financing sources could influence on the impact dimensions being addressed....... Social motives were found to go along with social impact targets. The results seem to support a resource dependence perspective (Drees & Heugens 2013): the more early-stage ventures rely on philanthropic support as an external funding source, the stronger they appear oriented towards social...

  17. Thermal analytical study of polyamide copolymer/Surlyn Ionomers Blends

    Energy Technology Data Exchange (ETDEWEB)

    Qin, C.; Ding, Y.P. [Baxter Healthcare Corp., Round Lake, IL (United States)

    1993-12-31

    Thermal analytical technique was used as a screening method to study polyamide(Nylon)/ethylene-co-methacrylic acid copolymer-based ionomer(Surlyn)blends. The retardation of crystallization process from molten state of Nylon-12 by the existence of the ionomer was observed, but the crystallization of Nylon-12 can not be thwarted even at high concentration of ionomers. Zinc ionomers shows stronger effect than sodium ionomers. A Nylon copolymer, polyamide-6,6-co-polyamide-6,10, was used to blend with different ionomers and the crystallization process from molten state of Nylon copolymer could be thwarted at high concentration of zinc ionomer even at very cooling rate. Interesting cold crystallization behavior of polyamide copolymer was observed during second DSC heating cycle in the temperature range of the melting process of ionomer.

  18. Structure-Properties of PPE Alloy by Reactive Blending

    Science.gov (United States)

    Furuta, Motonobu; Koyama, Yoshio; Inoue, Takashi

    Poly(phenylene ether) (PPE) is a high temperature polymer (Tg=210°C). Neat PPE is hardly melt-processed below its thermal decomposition temperature. It is believed that the melt-processability is only achieved by blending with polystyrene as a polymeric plasticizer. The polymeric plasticizer sacrifices the heat resistance; the Tg decreases almost linearly with polystyrene content. We found that PPE can react with poly(ethylene-co-glycidylmethacrylate) (EGMA) by melt mixing. Reactive blending of PPE with EGMA yielded an excellent engineering plastic with nice melt-processability, even when a small amount of EGMA (e.g., 5 wt%) was incorporated. The injection molded parts showed high impact strength, high temperature resistance, high tensile strength, and low dielectric loss. It can be classified as a super-engineering plastics. The computer simulation based on a particle-slip model revealed why the melt-processability is attained by the incorporation of polyolefin in pure PPE matrix.

  19. Dual Quaternion Blending Algorithm and Its Application in Character Animation

    Directory of Open Access Journals (Sweden)

    Xiang Feng

    2013-10-01

    Full Text Available In this paper we generalize established techniques and blending algorithm for quaternions to dual quaternions to include all rigid transformations, and implement real-time character animation with dual quaternions under the platform of OpenGL. Classical quaternions are restricted to the representation of rotations although combination of matrix calculation and quaternions operator has been a popular tool in character animation since 1990s. In character animation and some other applications of 3D computer graphics, we are actually faced with rigid transformation which just includes translation and rotation. Similar to the way quaternions represent rotations, dual quaternions represent rigid transformations. Algorithms based on dual quaternions own better properties than those based on quaternions in practical applications, which include reduced overhead, increased computational efficiency and coordinate invariance.. Finally we demonstrate the effectiveness and superiority of dual quaternions blending algorithm by cartoon male and female mesh models with the animation of walking and waving.  

  20. Molecular Dynamics Simulation of Miscibility in Several Polymer Blends

    CERN Document Server

    Ahmadi, Amirhossein

    2009-01-01

    The miscibility in several polymer blend mixtures (polymethylmethacrylate/polystyrene, (1,4-cis) polyisoprene/polystyrene, and polymethylmethacrylate/polyoxyethylene) has been investigated using Molecular Dynamics simulations for atomistic representations of the polymer chains. The trajectories obtained from simulation boxes representing the mixtures have been analyzed in terms of the collective scattering structure function. The Flory-Huggins parameter is determined from fits of the simulation results for this function to the random phase approximation expression. The numerical values of this parameter and its variation with temperature obtained with this procedure show a general qualitative and quantitative agreement with existing experimental data for the different systems. These results together with those previously obtained for the polyvylmethylether/polystyrene blends with the same method are compared with data yielded by other computational simpler approaches.

  1. Gelatin blends with alginate: gels for lipase immobilization and purification.

    Science.gov (United States)

    Fadnavis, Nitin W; Sheelu, Gurrala; Kumar, Bezavada Mani; Bhalerao, Mahendra U; Deshpande, Ashlesha A

    2003-01-01

    Blends of natural polysaccharide sodium alginate (5%) with gelatin (3%) cross-linked with glutaraldehyde provide beads with excellent compressive strength (8 x 10(4) Pa) and regular structure on treatment with calcium chloride. Lipases from porcine pancreas, Pseudomonas cepacia, and Candida rugosa were immobilized in such a blend with excellent efficiency. The immobilized enzymes were stable and were reused several times without significant loss of enzyme activity both in aqueous and reverse micellar media. The beads were functionalized with succinic anhydride to obtain beads with extra carboxylic acid groups. These functionalized beads were then successfully used for 7.4-fold purification of crude porcine pancreatic lipase in a simple operation of protein binding at pH 5 and release at pH 8.5.

  2. Instant blend from cassava derivatives produced by extrusion

    Directory of Open Access Journals (Sweden)

    Fernanda Rossi Moretti Trombini

    2016-03-01

    Full Text Available ABSTRACT: The current research aimed to evaluate the effects of extrusion parameters on the physical characteristics of extruded blends of cassava leaf flour and starch. A factorial central composite design with four independent variables and the response surface methodology were used to evaluate the results of color parameters (L*, a*, b*, water absorption index, water solubility index and paste properties, according to the variations in the leaf flour percentage (1.5 to 7.5%, extrusion temperature (60 to 100ºC, screw speed (175 to 231rpm and moisture (20 to 30%. Extrusion conditions affect color, water absorption and water solubility indexes and paste properties of blends. The intermediate tested conditions of variable parameters lead to obtain extruded products with higher cold viscosity and water absorption index and light color, desirable qualities for rapid preparation products.

  3. Multifilament cellulose/chitin blend yarn spun from ionic liquids.

    Science.gov (United States)

    Mundsinger, Kai; Müller, Alexander; Beyer, Ronald; Hermanutz, Frank; Buchmeiser, Michael R

    2015-10-20

    Cellulose and chitin, both biopolymers, decompose before reaching their melting points. Therefore, processing these unmodified biopolymers into multifilament yarns is limited to solution chemistry. Especially the processing of chitin into fibers is rather limited to distinctive, often toxic or badly removable solvents often accompanied by chemical de-functionalization to chitosan (degree of acetylation, DA, cellulose/chitin blend fibers using ionic liquids (ILs) as gentle, removable, recyclable and non-deacetylating solvents. Chitin and cellulose are dissolved in ethylmethylimidazolium propionate ([C2mim](+)[OPr](-)) and the obtained one-pot spinning dope is used to produce multifilament fibers by a continuous wet-spinning process. Both the rheology of the corresponding spinning dopes and the structural and physical properties of the obtained fibers have been determined for different biopolymer ratios. With respect to medical or hygienic application, the cellulose/chitin blend fiber show enhanced water retention capacity compared to pure cellulose fibers.

  4. Tunable Surface Properties of a Conductive PEDOT/EVAL blend

    DEFF Research Database (Denmark)

    Pizzi, Elisa; Martinelli, Andrea; D'Ilario, Lucio;

    Conductive polymers have been studied extensively during recent years. Especially,poly(3,4-ethylenedioxythiophene) (PEDOT) have found many application areas and arebroadly considered one of the most promising conductive polymers. In order to broadenthe application field of PEDOT we have developed...... an azide functional poly(3,4-ethylenedioxythiophene) (PEDOT-N3)1. The azide functional conductive polymer canbe postpolymerization functionalized to introduce a large range of molecules onto theconductive backbone through click chemistry2.Here we present a study of the incorporation of poly......(ethylene-co-vinyl alcohol) (EVAL)into a copolymer of EDOT and EDOT-N3 (poly(EDOT-co-EDOT-N3)). Poly(ethyleneco-vinyl alcohol) (EVAL) is known to swell in polar solvents, which was exploited inthis study to permit a good blending of the two polymers. Since both polymers haveresidual functional groups the polymer blend...

  5. X-ray photoelectron spectroscopic investigation of conducting polymer blends.

    Science.gov (United States)

    Süzer, S; Toppare, L; Hallam, K R; Allen, G C

    1996-06-01

    Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.

  6. AstroBlend: An Astrophysical Visualization Package for Blender

    CERN Document Server

    Naiman, J P

    2016-01-01

    The rapid growth in scale and complexity of both computational and observational astrophysics over the past decade necessitates efficient and intuitive methods for examining and visualizing large datasets. Here, I present {\\it AstroBlend}, an open-source Python library for use within the three dimensional modeling software, {\\it Blender}. While {\\it Blender} has been a popular open-source software among animators and visual effects artists, in recent years it has also become a tool for visualizing astrophysical datasets. {\\it AstroBlend} combines the three dimensional capabilities of {\\it Blender} with the analysis tools of the widely used astrophysical toolset, {\\it yt}, to afford both computational and observational astrophysicists the ability to simultaneously analyze their data and create informative and appealing visualizations. The introduction of this package includes a description of features, work flow, and various example visualizations. A website - www.astroblend.com - has been developed which incl...

  7. Blended learning:把教学要素融合

    Institute of Scientific and Technical Information of China (English)

    周华杰; 陈静姆; 阳燚; 张仙

    2004-01-01

    Blended learning是教育领域出现的一个新名词,但它的理念和思想却已经存在了多年。从本质上来讲,Blended learning是一种新型的学习方式或学习理念,它是指在E-learning中,按照系统论的观点和绩效方法,恰当结合传统学习手段和在线学习手段的学习方式。它的目标是使学习更容易、更便利,从而实现最好的学习效果。

  8. Mapping Cultural Frame Shifting in Interaction Design with Blending Theory

    DEFF Research Database (Denmark)

    Markussen, Thomas; Krogh, Peter Gall

    2008-01-01

    In this paper, we introduce Gilles Fauconnier & Mark Turner's blending theory as a new conceptual framework for explaining ‘cultural frame shifting' in interaction design. Cultural frame shifting is when people, through their explorative use of technology, are required imaginatively to reorganize...... their cultural background knowledge and expectations. In current HCI research it has occasionally been pointed out that a proper understanding of this phenomenon hinges on addressing the relationship between embodied interaction and cultural meaning construction as part of a larger interactive system. However...... the network model of mental spaces from Fauconnier & Turner's blending theory onto video material and interviews from initial qualitative use studies of a design case. In so doing we explore and argue for how meaning formation and embodied cognition coalesce in cultural frame shifting and provide a tool...

  9. Electrospinning polymer blends for biomimetic scaffolds for ACL tissue engineering

    Science.gov (United States)

    Garcia, Vanessa Lizeth

    The anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. Current ACL reconstructive strategies consist of using an autograft or an allograft to replace the ligament. However, limitations have led researchers to create tissue engineered grafts, known as scaffolds, through electrospinning. Scaffolds made of natural and synthetic polymer blends have the potential to promote cell adhesion while having strong mechanical properties. However, enzymes found in the knee are known to degrade tissues and affect the healing of intra-articular injuries. Results suggest that the natural polymers used in this study modify the thermal properties and tensile strength of the synthetic polymers when blended. Scanning electron microscopy display bead-free and enzyme biodegradability of the fibers. Raman spectroscopy confirms the presence of the natural and synthetic polymers in the scaffolds while, amino acid analysis present the types of amino acids and their concentrations found in the natural polymers.

  10. [Evaluating a blended-learning program on developing teamwork competence].

    Science.gov (United States)

    Aguado, David; Arranz, Virginia; Valera-Rubio, Ana; Marín-Torres, Susana

    2011-08-01

    The knowledge, skills and abilities that are required to work optimally in teams are critical for many types of work. Organizations can provide access to these skills by means of training programs. Diverse studies show how traditional in-site training methodologies can improve teamwork knowledge, skills and abilities. Nevertheless, in-site methods can be complemented with on-line strategies that result in blended-learning programs. The aim of this work is to analyze, following Kirkpatrick's assessment levels, the effectiveness of a blended-learning program of teamwork training in an organizational context. Carried out with 102 professionals, the results show participants' satisfaction with the program, high level of learning (of both declarative and procedural knowledge), and a moderate level of transfer of learning to the job.

  11. Rheological behavior of acrylic paint blends based on polyaniline

    Directory of Open Access Journals (Sweden)

    Alex da Silva Sirqueira

    Full Text Available Abstract The rheological properties of acrylic paints and polyaniline (PAni blends, with different contents of PAni doped by dodecyl benzene sulphonic acid (DBSA and, dispersed by mechanical stirrer and ultrasonic, were investigated by controlled shear rate testing ramps. The results showed that the commercial acrylic paint had tended to deliver the required stability on the blends, in order to avoid sedimentation process. All samples exhibited non-Newtonian flow behavior (shear thinning, increasing PAni content the flow behavior index (n decreased (0.41 to 0.11 and power law model were used to fitted the experimental curves. The results showed that the addition of PAni-DBSA affects the viscoelastic behavior of the mixtures due to the interactions between the components in the mixture. The best properties were obtained for samples 90/10 wt % dispersed by ultrasonic, indicating the feasibility of the usage as a conducting paint.

  12. Phase diagrams of binary crystalline-crystalline polymer blends.

    Science.gov (United States)

    Matkar, Rushikesh A; Kyu, Thein

    2006-08-17

    A thermodynamically self-consistent theory has been developed to establish binary phase diagrams for two-crystalline polymer blends by taking into consideration all interactions including amorphous-amorphous, crystal-amorphous, amorphous-crystal, and crystal-crystal interactions. The present theory basically involves combination of the Flory-Huggins free energy for amorphous-amorphous isotropic mixing and the Landau free energy of polymer solidification (e.g., crystallization) of the crystalline constituents. The self-consistent solution via minimization of the free energy of the mixture affords determination of eutectic, peritectic, and azeotrope phase diagrams involving various coexistence regions such as liquid-liquid, liquid-solid, and solid-solid coexistence regions bound by liquidus and solidus lines. To validate the present theory, the predicted eutectic phase diagrams have been compared with the reported experimental binary phase diagrams of blends such as polyethylene fractions as well as polycaprolactone/trioxane mixtures.

  13. Polymeric endoaortic paving: Mechanical, thermoforming, and degradation properties of polycaprolactone/polyurethane blends for cardiovascular applications.

    Science.gov (United States)

    Ashton, J H; Mertz, J A M; Harper, J L; Slepian, M J; Mills, J L; McGrath, D V; Vande Geest, J P

    2011-01-01

    Polymeric endoaortic paving (PEAP) is a process by which a polymer is endovascularly delivered and thermoformed to coat or "pave" the lumen of the aorta. This method may offer an improvement to conventional endoaortic therapy in allowing conformal graft application with reduced risk of endoleak and customization to complex patient geometries. Polycaprolactone (PCL)/polyurethane (PU) blends of various blend ratios were assessed as a potential material for PEAP by characterizing their mechanical, thermoforming and degradation properties. Biaxial tension testing revealed that the blends' stiffness is similar to that of aortic tissue, is higher for blends with more PCL content, and may be affected by thermoforming and degradation. Tubes of blends were able to maintain a higher diameter increase after thermoforming at higher PCL content and higher heating temperatures; 50/50 blend tubes heated to 55 °C were able to maintain 90% of the diameter increase applied. Delamination forces of the blends ranged from 41 to 235 N m⁻². In a Pseudomonas lipase solution, the 50/50 blend had a 94% lower degradation rate than pure PCL, and the 10/90 blend exhibited no degradation. These results indicate that PEAP, consisting of a PCL/PU blend, may be useful in developing the next generation of endoaortic therapy.

  14. Frying Stability Evaluation of Rice Bran Oil Blended with Soybean, Mustard and Palm Olein Oils

    Directory of Open Access Journals (Sweden)

    Prachi Srivastava

    2015-09-01

    Full Text Available Refined rice bran oil (RBO was blended with PUFA rich Soybean oil (SBO, MUFA rich Mustard oil (MO and SFA rich Palm Olein oil (POO to make a blend that had sufficient amount of Omega-3 fatty acid by mixing two or more oils in the ratio of 60:40 and 60:20:20 respectively. RBO and its blends were subjected to deep fat frying of potato chips at 180±10C for 24h. Oil samples were withdrawn after every four hours of frying and evaluated for peroxide value (PV, p-Anisidine value (p-AV, Total polar component (TPC and oil stability index (OSI for the RBO and its blends. In general, frying stability of RBO was improved by the blending, the Omega-6/Omega-3 ratio of the blend of RPM and RSM was in the recommended range (1:5-10, and in both cases it was observed to be 1:6. The OSI of RBO deteriorates 66% and it improved by blending with POO and it decline only 53% and 54% for the blend RP and RPM respectively. It was concluded that the blend having more than two oils (RBO+PO+MO was better in oxidative stability, nutritional value and also contain sufficient amount of Omega-3 fatty acid than that of the RBO and its other blends.

  15. Synthesis and characterization of soluble polypyrrole-poly({epsilon}-caprolactone) polymer blends with improved electrical conductivities

    Energy Technology Data Exchange (ETDEWEB)

    Basavaraja, C.; Kim, Won Jung; Kim, Dae Gun [Department of Chemistry and Institute of Basic Science, Inje University, Obang 607, Gimhae, Kyungnam 621-749 (Korea, Republic of); Huh, Do Sung, E-mail: chemhds@inje.ac.kr [Department of Chemistry and Institute of Basic Science, Inje University, Obang 607, Gimhae, Kyungnam 621-749 (Korea, Republic of)

    2011-10-03

    Highlights: {yields} Facile synthesis of a new polypyrrole (PPy) blend with biodegradable poly(e-caprolactone) (PCL) to form PPy - PCL. {yields} PPy - PCL blend is soluble in organic solvent in spite that the pure PPy is nearly insoluble in general organic solvents. {yields} Improvement in DC conductivity was observed in the PPy - PCL blend although the PCL is an insulator. {yields} Temperature-dependent DC conductivity for the blend has been explained by suitable mode. - Abstract: Polypyrrole-poly({epsilon}-caprolactone) (PPy-PCL) blends were prepared through an in situ deposition technique wherein different amounts of poly({epsilon}-caprolactone) were added during the polymerization of pyrrole. Ammonium persulfate was used as an oxidant in the polymerization of polypyrrole (PPy). Compared with pure PPy, the blends showed higher solubility in many organic solvents. The composition and structural characteristics of PPy-PCL were determined by Fourier transform infrared, ultraviolet-visible, and X-ray photoelectron spectroscopic methods. Scanning electron and transmission electron microscopic methods were performed to observe the morphology of the PPy-PCL blends. The temperature-dependent conductivity of the PPy-PCL blends was measured at 300-500 K. The conductivity increased with increasing PCL concentration in the blends, which can be explained by the increased mobility of charge carriers at high PCL concentrations. Based on the temperature dependence of the electrical conductivity, hopping may be the conduction mechanism involved in the PPy-PCL blending process.

  16. Property Analysis of Ethanol--Natural Gasoline--BOB Blends to Make Flex Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Alleman, Teresa L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yanowitz, Janet [Ecoengineering, Inc., Sharonville, OH (United States)

    2016-11-01

    Ten natural gasolines were analyzed for a wide range of properties, including Reid vapor pressure (RVP), benzene, sulfur, distillation, stability, metals, and aromatic content, to determine their quality. Benzene and sulfur content were sufficiently low in all but one of the samples that they could be blended without further upgrading. Four of these samples were selected to blend with blendstock for oxygenate blending (BOB) and ethanol to produce E51, E70, and E83 blends, targeting 7.8 and 9.0-psi finished fuels. The volume of each component in the blend was estimated using the Reddy model, with the assumption that the BOB and natural gasoline blend linearly and behave as a single component in the model calculations. Results show that the Reddy model adequately predicts the RVP of the finished blend for E51 and E70, but significantly underpredicts the RVP of E83 blends by nearly 2 psi. It is hypothesized that the underprediction is a function of the very low aromatic content of the E83 blends, even compared to the E51 and E70 blends.

  17. Supertoughened renewable PLA reactive multiphase blends system: phase morphology and performance.

    Science.gov (United States)

    Zhang, Kunyu; Nagarajan, Vidhya; Misra, Manjusri; Mohanty, Amar K

    2014-08-13

    Multiphase blends of poly(lactic acid) (PLA), ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) terpolymer, and a series of renewable poly(ether-b-amide) elastomeric copolymer (PEBA) were fabricated through reactive melt blending in an effort to improve the toughness of the PLA. Supertoughened PLA blend showing impact strength of ∼500 J/m with partial break impact behavior was achieved at an optimized blending ratio of 70 wt % PLA, 20 wt % EMA-GMA, and 10 wt % PEBA. Miscibility and thermal behavior of the binary blends PLA/PEBA and PLA/EMA-GMA, and the multiphase blends were also investigated through differential scanning calorimetric (DSC) and dynamic mechanical analysis (DMA). Phase morphology and fracture surface morphology of the blends were studied through scanning electron microscopy (SEM) and atomic force microscopy (AFM) to understand the strong corelation between the morphology and its significant effect on imparting tremendous improvement in toughness. A unique "multiple stacked structure" with partial encapsulation of EMA-GMA and PEBA minor phases was observed for the PLA/EMA-GMA/PEBA (70/20/10) revealing the importance of particular blend composition in enhancing the toughness. Toughening mechanism behind the supertoughened PLA blends have been established by studying the impact fractured surface morphology at different zones of fracture. Synergistic effect of good interfacial adhesion and interfacial cavitations followed by massive shear yielding of the matrix was believed to contribute to the enormous toughening effect observed in these multiphase blends.

  18. Effects of mixing temperature on mechanical properties of TPU/NR blends

    Science.gov (United States)

    Ahad, Nor Azwin; Ahmad, Sahrim Hj

    2013-05-01

    Blending method of two or more polymer is a well-established strategy to modify the physical properties without synthesizing the new polymer system. However, it is difficult to obtain homogeneous polymer blends because blending polymer requires suitable processing parameters. In this study, the effect of mixing temperature on tensile properties of the thermoplastic polyurethane (TPU) with natural rubber (NR) blends was investigated as the one of processing parameters in obtaining homogeneous polymer blends. The blends were prepared via melt blending technique with the different TPU wt% of 85, 65, 45 and 25 at four different mixing temperature; 180 °C, 190 °C, 200 °C and 210 7°C. The blend with 85% TPU shows the maximum tensile strength and elongation at breaks value at 180 %C mixing temperature. The viscosity of the polymer reduced at higher temperature. Also, the movements of molecules are more worthy because of poor molecule interaction. This will affect to mechanical properties of the blends. In general, it was observed that the mixing temperature is one of the important parameter in acquiring blends having optimum mechanical properties.

  19. Recycling Waste Natural Rubber Latex by Blending with Polystyrene - Characterization of Mechanical Properties

    Science.gov (United States)

    Boondamnoen, O.; Ohshima, M.; Azura, A. R.; Chuayjuljit, S.; Ariffin, A.

    Waste natural rubber latex was blended with polystyrene (WNRL/PS) for recycling. A mixture with a 50/50 ratio of rubber to PS was blended by an internal mixer (Haake) at 140 °C and 60 rpm. The PS became the matrix, and the WNRL was dispersed within the matrix. Dynamically vulcanized natural rubber/PS (NRv/PS) blends and natural rubber/PS (NR/PS) blends without vulcanization were also prepared in the same way for comparison. The tensile properties and morphologies of all blends were investigated. The crosslinking density was determined by using the Flory-Rehner equation. The experiments showed that the WNRL/PS blend exhibited a higher tensile strength, Young's modulus and crosslinking density, but a lower elongation at break, than the NRv/PS and NR/PS blends. SEM observations of the tensile fracture surface and TEM observations of the blend morphology indicated that the WNRL/PS blend needed a higher energy to break than the NRv/PS and NR/PS blends.

  20. Water resistance and thermal properties of polyvinyl alcohol-starch fiber blend film

    Science.gov (United States)

    Salleh, M. S. N.; Nor, N. N. Mohamed; Mohd, N.; Draman, S. F. Syed

    2017-02-01

    The growing attention of starch fiber (SF) has led to the innovation of Polyvinyl Alcohol-SF (PVA-SF) blends. This blend is regarded as the biodegradable material which aims to reduce the accumulation of synthetic polymer solid waste derived from petroleum. In this study, the thermal blending characterizations of PVA-SF were investigated by differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The water resistance of the blend was also evaluated to study the polarity of the blends. The blend was prepared by plasticizing the polyvinyl alcohol with glycerol and distilled water with the addition of starch fiber. The incorporation of SF to the blends was at 10 wt% to 50 wt% composition. Based on the thermal analysis, PVA-SF blends were suitable for processing at high temperatures, which can be seen by the shifted onset degradation temperature to a higher temperature. This is because cyclic hemiacetals which were provided by SF can act to prevent the thermal attacks. Conversely, increasing the starch fiber proportion to the film blend reduce the endothermic peak amplitude in the DSC thermogram. It was found that PVA-SF blend at the higher composition of SF had the highest water resistance. This may be attributed to the content of fibre in SF which is hydrophilic.

  1. Spanwise transition section for blended wing-body aircraft

    Science.gov (United States)

    Hawley, Arthur V. (Inventor)

    1999-01-01

    A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.

  2. Towards MOOC for Technical Courses: A Blended Learning Empirical Analysis

    OpenAIRE

    Siti Feirusz Ahmad Fesol

    2016-01-01

    Massive Open Online Learning (MOOC) is one of the rapidly growing and the most trending online learning platform throughout the world. As reported by Class Central up until December 2015, there are more than a total of 4200 courses, which enrolled more than 35 million students and adopted by more than 500 universities all over the world. Thus, the objective of this study is to identify the students’ readiness towards MOOC technical courses based on blended learning approach. This study adapte...

  3. The evolution of eLearning background, blends and blackboard....

    Science.gov (United States)

    Sleator, Roy D

    2010-01-01

    This review of eLearning is divided into three sections: the first charts the evolution of eLearning from early correspondence courses to the current computer mediated approaches to distributed learning. The second section deals with the concept of blended learning; combining best practice in face-to-face and online learning. The final section focuses on current platform technologies in eLearning and outlines the strengths and weaknesses of learning management systems such as Blackboard.

  4. INVESTIGATION OF LAMINAR FLAME SPEED OF ALTERNATIVE LIQUID FUEL BLENDS

    OpenAIRE

    2016-01-01

    The rapid fluctuation in oil prices and increased demand of clean fuels to reduce emissions has forced the researchers to find alternative fuels that can give the same or better overall fuel characteristics. This thesis aims at looking into the prospects of Gas to Liquid (GTL) fuel as an alternative fuel for Internal Combustion Engines (ICEs), by investigating the flame speed of GTL fuel and its 50/50 (by volume) blend with conventional diesel. The tests were conducted in a new...

  5. COINTEGRATION IN THE OIL MARKET AMONG REGIONAL BLENDS

    OpenAIRE

    Neil A. Wilmot

    2013-01-01

    The integration of crude oil spot prices, from different geographic regions is examined using the residual-based cointegration test of Gregory and Hansen (1996), which allows for endogenously determined structural breaks. While traditionally, the focus has been on three global benchmark crudes (WTI, Brent and Dubai Fateh), herein the relationship among secondary, regional blends (Edmonton Par, Western Canadian Select, Bonny Light and Mexican Maya) is examined with implications for the ‘global...

  6. Blending Audience Response Systems into an Information Systems Professional Course

    Directory of Open Access Journals (Sweden)

    Stephen Burgess

    2016-05-01

    The paper reports the findings of a pilot scheme designed to explore the efficacy of the technology. Use of a blended learning framework to frame the discussion allowed the authors to consider the readiness of institution, lecturers, and students to use ARS. From a usage viewpoint, multiple choice questions lead to further discussion of student responses related to important issues in the unit. From an impact viewpoint the use of ARS in the class appeared to be successful, but some limitations were reported.

  7. Controlled release implants based on cast lipid blends.

    Science.gov (United States)

    Kreye, F; Siepmann, F; Zimmer, A; Willart, J F; Descamps, M; Siepmann, J

    2011-05-18

    The aim of this study was to use lipid:lipid blends as matrix formers in controlled release implants. The systems were prepared by melting and casting and thoroughly characterized before and after exposure to the release medium. Based on the experimental results, a mechanistic realistic mathematical model was used to get further insight into the underlying drug release mechanisms. Importantly, broad spectra of drug release patterns could be obtained by simply varying the lipid:lipid blend ratio in implants based on Precirol ATO 5 (glyceryl palmitostearate):Dynasan 120 (hardened soybean oil) mixtures loaded with propranolol hydrochloride. Release periods ranging from a few days up to several months could be provided. Interestingly, the drug release rate monotonically decreased with increasing Dynasan 120 content, except for implants containing about 20-25% Precirol, which exhibited surprisingly high release rates. This could be attributed to the incomplete miscibility of the two lipids at these blend ratios: DSC thermograms showed phase separation in these systems. This is likely to cause differences in the implants' microstructure, which determines the mobility of water and dissolved drug as well as the mechanical stability of the systems. Purely diffusion controlled drug release was only observed at Precirol ATO 5 contents around 5-10%. In all other cases, limited drug solubility effects or matrix former erosion are also expected to play a major role. Thus, lipid:lipid blends are very interesting matrix formers in controlled release implants. However, care must be taken with respect to the mutual miscibility of the compounds: in case of phase separation, surprisingly high drug release rates might be observed.

  8. STUDY ON HIGH CONTENT OF BLENDS IN CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The technology of activation by a]dding few activators(<1%) to increase the amount of blends in cement was investigated.The results show that outer activation has a remarkable effect on improving the physical properties of slag cement,flyash cement and volcanic cement.For example,the compressive strength was increased by 5-10 MPa.Morever,the application of activation is beneficial to grind-aiding,early strength and water-reducing etc.

  9. Towards MOOC for Technical Courses: A Blended Learning Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Siti Feirusz Ahmad Fesol

    2016-12-01

    Full Text Available Massive Open Online Learning (MOOC is one of the rapidly growing and the most trending online learning platform throughout the world. As reported by Class Central up until December 2015, there are more than a total of 4200 courses, which enrolled more than 35 million students and adopted by more than 500 universities all over the world. Thus, the objective of this study is to identify the students’ readiness towards MOOC technical courses based on blended learning approach. This study adapted quantitative based approach to analyse the data gathered.  Descriptive analysis and factor analysis are used to empirically analyse a total of 39 items on student attitude towards blended learning. This study successfully in developing six dimensions of student attitude towards the implementation of MOOC learning. The attributes namely are attitude towards learning flexibility, online learning, study management, technology, online interaction, and classroom learning. The findings summarized that, when students had a positive attitude towards learning flexibility, online learning, study management, technology, and online interaction, the students were more likely to adapt to blended learning and highly ready towards MOOC learning. On the other hand, when students had a positive attitude towards classroom learning, they were less likely ready towards MOOC learning, as they would prefer to meet their lecturers and friends in a physical lecture class compared to on the web-based. Understanding of student’s readiness towards MOOC learning based on blended learning approach is one of the critical success factors for implementing successful MOOC by higher learning institutions.

  10. Teaching English Medical Writing in a Blended Setting

    Directory of Open Access Journals (Sweden)

    Jafar Asgari Arani

    2012-12-01

    Full Text Available Medical writing activities which may have a context and seem to be engaging may be perceived as demotivating by the students of medicine. This opinion was confirmed by the learners' responses to the open-ended question given to them prior to this study. In their responses students evaluated the writing section of English course negatively. The negative views about the writing course posed a problem to the class teacher. The computer technology and the Internet can easily be integrated into language classroom if activities are designed carefully, and carried out systematically. These attempts brought about a new understanding to teaching and learning: blended learning (BL. The purpose of this research was to investigate students of medicine attitude to blended writing classes. It was conducted with second year learners in the Faculty of Medicine at Kashan University of Medical Sciences. The first reflection aimed at finding out medical students' attitude toward blended writing lessons. Although learners' attitude to writing lessons was negative in the first reflections, they changed into positive in the latter ones. The findings indicated that blended writing class had changed students' perception of writing lessons positively. Therefore, this kind of classes may help students develop a positive attitude towards writing by providing meaningful writing opportunities. Like the student portfolio before it, the weblog faces challenges with practicality and security, but ultimately provides an alternative way to teach and assess authentic writing and reading skills. Blog Assisted Language Learning not only provides teachers with an exciting new way to approach communicative language learning, it also gives the students a new reason to enjoy writing! The paper concludes that Internet tools have the potential to be a transformational technology for teaching and learning writing, and teachers ought to give strong consideration to the setting up their

  11. MALDI-ToF Analysis of Model Copolymer Blends

    Science.gov (United States)

    Pan, David; Arnould, Mark

    2008-03-01

    MALDI-ToF mass spectrometry was used to determine the composition of a low MW styrene (S) / n-butyl acrylate (nBA) copolymer. Bernoullian chain statistics were used to predict the copolymer distribution and confirm that MALDI-ToF detects the correct composition. The copolymer was blended with a low MW polystyrene homopolymer having the same end group as the copolymer at several levels to determine if MALDI-ToF could be used to calculate the amount of homopolymer by subtracting homopolymer peak areas. It is found that, while MALDI-ToF can be used to monitor the amount of homopolymer blended into the copolymer, the observed increase is always greater than the actual amount added, e.g. up to 13% error. This could be due to the fact that the homopolymer ionizes more efficiently than the low MW copolymer. A model to improve the accuracy of the calculated amount of homopolymer in the blend is discussed.

  12. The production of stable bitumen-polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, J.; Sokic, M. (Faculty of Technology and Metallurgy, Univ. Belgrade (Yugoslavia)); Smiljanic, M.; Pab, I. (Highway Inst., Belgrade (Yugoslavia)); Neumann, H.J.; Rahimian, I. (German Inst. for Petroleum Research, Clausthal-Zellerfeld (Germany))

    1993-01-01

    If either blown bitumen or bitumens of inadequate origin and type are used for the production of bitumen-polymer blends containing SBS- and/or SBR-elastomers, it is often not possible to obtain stable homogeneous bitumen-polymer blends. In that case pretreatment of the elastomer component is necessary. The production of stable bitumen-polymer blends from SBS- and SBR-elastomers and blown bitumens from Yugoslav refineries in Novi Sad and Pancevo were studied in this paper. Pretreatment of the elastomer components was performed with a residue of the distillation of fatty acids and/or with pyrolysis oil from a naphtha steam pyrolysis unit. Infrared spectroscopy was used to determine the kinetics of the dissolution of the elastomers in the bitumen. The rate of dissolution of SBR-elastomer was practically independent of the bitumen type. In the case of SBS-elastomer, however, the kinetics of the dissolving process was strongly influenced by the bitumen type. The origin of bitumen influenced the dissolution kinetics too. (orig.).

  13. Utilization of Renewable Oxygenates as Gasoline Blending Components

    Energy Technology Data Exchange (ETDEWEB)

    Yanowitz, J.; Christensen, E.; McCormick, R. L.

    2011-08-01

    This report reviews the use of higher alcohols and several cellulose-derived oxygenates as blend components in gasoline. Material compatibility issues are expected to be less severe for neat higher alcohols than for fuel-grade ethanol. Very little data exist on how blending higher alcohols or other oxygenates with gasoline affects ASTM Standard D4814 properties. Under the Clean Air Act, fuels used in the United States must be 'substantially similar' to fuels used in certification of cars for emission compliance. Waivers for the addition of higher alcohols at concentrations up to 3.7 wt% oxygen have been granted. Limited emission testing on pre-Tier 1 vehicles and research engines suggests that higher alcohols will reduce emissions of CO and organics, while NOx emissions will stay the same or increase. Most oxygenates can be used as octane improvers for standard gasoline stocks. The properties of 2-methyltetrahydrofuran, dimethylfuran, 2-methylfuran, methyl pentanoate and ethyl pentanoate suggest that they may function well as low-concentration blends with gasoline in standard vehicles and in higher concentrations in flex fuel vehicles.

  14. Review Of Rheology Models For Hanford Waste Blending

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.; Stone, M.

    2013-09-26

    The area of rheological property prediction was identified as a technology need in the Hanford Tank Waste - waste feed acceptance initiative area during a series of technical meetings among the national laboratories, Department of Energy-Office of River Protection, and Hanford site contractors. Meacham et al. delivered a technical report in June 2012, RPP-RPT-51652 ''One System Evaluation of Waste Transferred to the Waste Treatment Plant'' that included estimating of single shell tank waste Bingham plastic rheological model constants along with a discussion of the issues inherent in predicting the rheological properties of blended wastes. This report was selected as the basis for moving forward during the technical meetings. The report does not provide an equation for predicting rheological properties of blended waste slurries. The attached technical report gives an independent review of the provided Hanford rheological data, Hanford rheological models for single tank wastes, and Hanford rheology after blending provided in the Meacham report. The attached report also compares Hanford to SRS waste rheology and discusses some SRS rheological model equations for single tank wastes, as well as discussing SRS experience with the blending of waste sludges with aqueous material, other waste sludges, and frit slurries. Some observations of note: Savannah River Site (SRS) waste samples from slurried tanks typically have yield stress >1 Pa at 10 wt.% undissolved solids (UDS), while core samples largely have little or no yield stress at 10 wt.% UDS. This could be due to how the waste has been processed, stored, retrieved, and sampled or simply in the differences in the speciation of the wastes. The equations described in Meacham's report are not recommended for extrapolation to wt.% UDS beyond the available data for several reasons; weak technical basis, insufficient data, and large data scatter. When limited data are available, for example two to

  15. Compatibility Studies on Elastomers and Polymers with Ethanol Blended Gasoline

    Directory of Open Access Journals (Sweden)

    J. S. Dhaliwal

    2014-01-01

    Full Text Available This paper reports the compatibility studies of 10% ethanol blended gasoline (E10 with four types of elastomer materials, namely, Neoprene rubber, Nitrile rubber, hydrogenated Nitrile butadiene rubber (HNBR, and Polyvinyl chloride/Nitrile butadiene rubber blend (PVC/NBR, and two types of plastic materials, namely, Nylon-66 and Polyoxymethylene (Delrin. These materials have applications in automotives as engine seals, gaskets, fuel system seals and hoses, and so forth. Two types of the ethanol blended gasoline mixtures were used: (a gasoline containing 5% ethanol (E5, which is commercial form of gasoline available in India, and (b gasoline containing 10% ethanol (E10. The above materials were immersed in E5 and E10 for 500 hrs at 55°C. A set of eight different properties in E5 and E10 (visual inspection, weight change, volume change, tensile strength, percent elongation, flexural strength, impact strength, and hardness were measured after completion of 500 hrs and compared with reference specimens (specimens at 55°C without fuel and specimens at ambient conditions. Variation observed in different materials with respect to the above eight properties has been used to draw inference about the compatibility of these elastomeric/polymer materials with E10 fuel vis-à-vis E5 fuels. The data presented in this study is comparative in nature between the results of E10 and E5.

  16. Compatibility of novel blends from polyolefin and coal

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F.; Zhou, A. [Xi' an Jiaotong University, Xi' an (China). School of Material Science and Engineering

    2004-06-01

    Melt blends of low-density polyethylene (LDPE), ethylene vinyl acetate (EVA) and coal with various compositions were prepared through reactive extrusion. The rheological behaviour was studied with respect to the effect of blend ratio, shear rate using a rheometer to gain an understanding of processing parameters controlling industrial application. Compatibility was also evaluated by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results revealed that LDPE/EVA/coal is a partly compatible system showing pseudo-plastic behaviour, increase in viscosity with increased coal content appears evident only at low shear rate, viscosity tends to keep consistent approximately but varies with coal content at higher shear rate. Viscosity and compatibility of blends are attributed to changes in LDPE crystalline structure and entanglement, together with interaction between macromolecular aliphatic chains in coal and amorphous phase in LDPE and EVA at the boundaries of phases, which appears during the re-arrangement process of the crystalline structure. 8 refs., 5 figs., 3 tabs.

  17. Miscibility of Polystyrene and Lighted Sulfonated Polystyrene Blends

    Science.gov (United States)

    Zhou, N. C.; Burghardt, W. R.; Composto, R. J.

    2005-03-01

    The blend miscibility of deuterated polystyrene (dPS) and lighted sulfonated poly(styrene-ran-sulfonated polystyrene) (P (S-SS)) has been examined by forward recoil spectrometry (FRES). Equilibrium coexistence compositions were determined for dPS:P(S-SSx) blends where x is the mole percent of sulfonation.At x = 0.2%, the blends are fully miscible at 150°C to 190°C, while at x = 2.6% the system fully immiscible at the same temperatures. Intermediate levels of sulfonation (0.7, 1.0 and 1.2%) are partially miscible and exhibit an upper critical solution temperature (UCST). This behavior is attributed to the dilution of repulsive intra-molecular interaction between the ionic and non-ionic groups in the copolymer due to favorable interactions with the non-ionic group of the homopolymer PS. Estimates using the Flory-Huggins and the copolymer effect theories found a large ( 20) positive monomer-monomer interaction parameter between styrene and styrene sulfonate. This large interaction parameter might drive phase separation within a compositionally disperse random copolymers sample.

  18. Sintering Properties and Optimal Blending Schemes of Iron Ores

    Institute of Scientific and Technical Information of China (English)

    Dauter0liveira; WUSheng—li; DAIYu—ming; XUJian; CHEN Hong

    2012-01-01

    In order to obtain good sintering performance, it is important to understand sintering properties of iron ores. Sintering properties including chemical composition, granulation and high-temperature behaviors of ores from China, Brazil and Australia. Furthermore, several indices were defined to evaluate sintering properties of iron ores. The results show that: for chemical composition, Brazilian ores present high TFe, low SiOz, and low Alz03 con- tent. For granulation, particle diameter ratio of Brazilian ores are high; particle intermediate fraction of Chinese con- centrates are low; and average particle size and clay type index of Australian ores are high. For high-temperature properties, ores from China, Brazil and Australia present different characteristics. Ores from different origins should be mixed together to obtain good high-temperature properties. According to the analysis of each ore's sintering prop- erties, an ore blending scheme (Chinese concentrates 20 ~-1- Brazilian ores 400//oo -k Australian ores 40 ~) was sugges- ted. Moreover, sinter pot test using blending mix was performed, and the results indicated that the ore blending scheme led to good sintering performance and sinter quality.

  19. Blended Simulation Progress Testing for Assessment of Practice Readiness

    Science.gov (United States)

    Smithburger, Pamela; Donihi, Amy Calabrese; Empey, Philip; Kobulinsky, Lawrence; Seybert, Amy; Waters, Thomas; Drab, Scott; Lutz, John; Farkas, Deborah; Meyer, Susan

    2017-01-01

    Objective. To design an assessment of practice readiness using blended-simulation progress testing. Design. A five-station, blended simulation assessment was developed to evaluate patient care outcomes in first- and third-year pharmacy (P1 and P3) students, as well as first-year postgraduate (PGY1) pharmacy residents. This assessment of practice readiness included knowledge and performance evaluations administered as a progress test. Assessment. Eighteen PGY1 residents, 108 P3 students, and 106 P1 students completed the assessment. P3 students scored significantly higher than P1 students across all evaluations. Third-year pharmacy students scored significantly lower than PGY1 residents in interprofessional communications and attitudes of ownership in a standardized colleague/mannequin model station, and in patient communication in a standardized patient station. Conclusion. Learners demonstrated evolving skills as they progressed through the curriculum. A blended simulation integrated progress test provides data for improvement of individual student clinical skills, informs curricular advancement, and aligns curricular content, process, and outcomes with accreditation standards.

  20. Acute aqueous toxicities of diesel-biodiesel blends

    Energy Technology Data Exchange (ETDEWEB)

    Hollebone, B.P.; Ho, N.; Landriault, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Science and Technology Branch, Environmental Science and Technology Centre; Harrison, S. [Science Applications International Corp., SAIC Canada, Ottawa, ON (Canada); Doe, K.; Jackman, P. [Environment Canada, Moncton, NB (Canada). Toxicology Laboratory, Environmental Science Centre

    2008-07-01

    The renewed interest in biodiesels as a new transportation fuel was discussed. Although there are several advantages to using biodiesels, their environmental behaviours and effects need to be evaluated along with the risks associated with their use, such as accidental releases of these biodiesels to the environment. The wide variability of biodiesels may result in different toxicological impacts, depending on the fuel feedstock. This study evaluated the aqueous effects of biodiesels from several commonly available feedstocks and their blends with petroleum diesel. Since most of the commercial uses of these products are currently focused on road-use, this study focused on the effects of these fuels in fresh-water. Biodiesels derived from soy, canola and waste restaurant oil feedstocks were used in the study. The acute toxicities of these biodiesels and biodiesel/petroleum diesel fuel blends were reported for 3 test species used by Environment Canada for toxicological evaluation, notably rainbow trout, the water flea, and a luminescent bacterium. The correlations between acute toxicity, water accommodated fractions (WAF) concentrations and fuel property data were examined. The study revealed that biodiesel is significantly less acutely toxic than petroleum diesels in potential ecological impacts. However, the biodiesel-diesel blends were found to be more acutely toxic than a linear dilution model predicts. 11 refs., 6 tabs., 3 figs.

  1. Polyaniline synthesized with functionalized sulfonic acids for blends manufacture

    Directory of Open Access Journals (Sweden)

    Mara Joelma Raupp Cardoso

    2007-12-01

    Full Text Available Polyaniline (PAni, an electronic conductive polymer, has poor mechanical properties, such as low tensile, compressive and flexural strength that render PAni a non-ideal material to be processed for practical applications. Desired properties of polyaniline can be enhanced by mixing it with a polymer that has good mechanical properties. In this work, PAni was synthesised using functionalized sulfonic acids like camphorsulfonic acid (CSA and dodecilbenzene sulfonic acid (DBSA in order to promote PAni doping and improve its solubility, making possible conductive blends manufacture. The different forms of PAni were characterized by infra-red spectroscopy, thermal analysis, scanning electron microscopy and conductivity measurements. A conductive blend composed of PAni/DBSA and lower density polyethylene (LDPE was obtained via solubilization method and its thermal, morphological and electrical properties were investigated. Concentrations as low as 5 wt. (% of PAni was able to lead to electrical conductivities of PAni/LDPE blends in the range of 10-3 S.cm-1, showing great potential to be used in antistatic packing, electromagnetic shielding, anti-corrosion shielding or as a semiconductor.

  2. Are we ready for blended learning in medical education?

    Directory of Open Access Journals (Sweden)

    Aneesh Basheer

    2016-10-01

    Full Text Available Blended learning has other indirect positive effects as well. One innovative byproduct of blended learning is the flipped classroom; the sequence of events customary to the traditional classroom teaching are reversed.2 Traditional learning starts with the teacher providing a predominant cognitive (knowledge component and requires the students to follow it up with self-study and expansion of knowledge leading to higher levels of learning. The teacher plays the role of subject expert in general. In contrast, the learning material or at least a major part of it is provided to students before the scheduled class. The teacher uses the face to face session to engage students in interactive discussions, group tasks and other activities. This also has the advantage of making the learning process active, learner-centered and more retentive, reducing distraction and promoting higher levels of learning.3,4 Moreover, there is enough data to indicate that students are highly satisfied with the blended learning experience, particularly flipped classrooms.

  3. MOTIVATING ADULT LEARNERS USING BLENDED LEARNING IN HIGHER EDUCATION INSTITUTION

    Directory of Open Access Journals (Sweden)

    Liyana Binti Ahmad Afip

    2014-07-01

    Full Text Available The process of teaching and learning is one of the most common issues discusses by educators and students regardless of in primary, secondary or even in tertiary level of education. It is important for the educators to ensure that learners especially those in tertiary education are motivated in learning thus promoting life-long learning. In line with the MyBrain15‟s programme launched by the Government of Malaysia which targeted 60,000 PhD holders among Malaysian by the year 2023, it is important to ensure that the learners are motivated to learn. Therefore, ARCS Model of Motivational Design need to be implemented in the curriculum in order to motivate the students as well as promoting autonomy in learning. The integration of technology in curriculum will also helps to provide a new dimension of learning experience for both the educators and learners. This paper proposes the integration of blended learning and ARCS model to be implemented in higher education institution to improve the quality of teaching and learning process. The focus of this paper is on knowing the adult learners, understanding the implementation of ARCS motivational model in teaching and learning process, understanding the precise definition of blended learning, the approaches in the implementation, the advantages and disadvantages of blended learning and finally the implication in the teaching and learning experience.

  4. Contrasting performance of donor-acceptor copolymer pairs in ternary blend solar cells and two-acceptor copolymers in binary blend solar cells.

    Science.gov (United States)

    Khlyabich, Petr P; Rudenko, Andrey E; Burkhart, Beate; Thompson, Barry C

    2015-02-04

    Here two contrasting approaches to polymer-fullerene solar cells are compared. In the first approach, two distinct semi-random donor-acceptor copolymers are blended with phenyl-C61-butyric acid methyl ester (PC61BM) to form ternary blend solar cells. The two poly(3-hexylthiophene)-based polymers contain either the acceptor thienopyrroledione (TPD) or diketopyrrolopyrrole (DPP). In the second approach, semi-random donor-acceptor copolymers containing both TPD and DPP acceptors in the same polymer backbone, termed two-acceptor polymers, are blended with PC61BM to give binary blend solar cells. The two approaches result in bulk heterojunction solar cells that have the same molecular active-layer components but differ in the manner in which these molecular components are mixed, either by physical mixing (ternary blend) or chemical "mixing" in the two-acceptor (binary blend) case. Optical properties and photon-to-electron conversion efficiencies of the binary and ternary blends were found to have similar features and were described as a linear combination of the individual components. At the same time, significant differences were observed in the open-circuit voltage (Voc) behaviors of binary and ternary blend solar cells. While in case of two-acceptor polymers, the Voc was found to be in the range of 0.495-0.552 V, ternary blend solar cells showed behavior inherent to organic alloy formation, displaying an intermediate, composition-dependent and tunable Voc in the range from 0.582 to 0.684 V, significantly exceeding the values achieved in the two-acceptor containing binary blend solar cells. Despite the differences between the physical and chemical mixing approaches, both pathways provided solar cells with similar power conversion efficiencies, highlighting the advantages of both pathways toward highly efficient organic solar cells.

  5. LDPE/PHB blends filled with castor oil cake

    Science.gov (United States)

    Burlein, Gustavo A.; Rocha, Marisa C. G.

    2015-05-01

    The response surface methodology (RSM) is a collection of mathematical techniques useful for developing, improving and optimizing process. In this study, RSM technique was applied to evaluate the effect of the components proportion on the mechanical properties of low density polyethylene (LDPE)/ poly (3-hydroxy-butyrate) (PHB) blends filled with castor oil cake (CC). The blends were prepared by melt mixing in a twin screw extruder. Low density polyethylene, poly (3-hydroxy-butyrate) and castor oil pressed cake were represented by the input variables designated as LDPE, PHB and CC, respectively. As it was desirable to consider the largest LDPE content in the ternary system, the components of the mixture were subjected to the following constraints: 0.7 ≤ LDPE ≤ 1.0, 0≤ PHB≤0.3 e 0 ≤ CC ≤0.3. The mechanical properties of the different mixtures were determined by conventional ASTM tests and were evaluated through analysis of variance performed by the Minitab software. Some polynomial equations were tested in order to describe the mechanical behavior of the samples. The quadratic model in pseudo components was selected for describing the tensile behavior because it was the most efficient from a statistical point of view (p-value ≤ 0.05; coefficient of determination (r2) close to 1 and variation inflation factor (VIF) values castor oil cake to LDPE. The morphological study of the materials obtained showed that LDPE/PHB blends are immiscible and form morphological structures with well distinguished phase boundaries between dispersed phase and matrix. Biodegradation was evaluated burying the samples in simulated soil for different periods of time. The LDPE/PHB/CC mixtures with higher content of PHB showed more pronounced degradation. Under the experimental conditions studied the LDPE/CC compositions presented no degradation. However, the loss of mass of the LDPE/PHB/CC mixtures was higher than the loss of mass of the corresponding LDPE/PHB binary blend. This

  6. Performance characteristics of mix oil biodiesel blends with smoke emissions

    Directory of Open Access Journals (Sweden)

    Sanjay Mohite

    2016-08-01

    Full Text Available Fossil fuel resources are being depleted day by day and its use affects the environment adversely. Renewable energy is one of the alternate for sustainable development and biodiesel is one of the suitable alternate which can replace the diesel. The major hurdles in the successful commercialization of biodiesel are high feedstock cost and conversion technology to reduce viscosity. The choice of raw material and biodiesel production method must depend upon techno-economical view. There are some specific regions for different types of oil availability. It is therefore required to produce biodiesel from the mixture of oils to fulfill the requirements of energy demand in a particular country according to its suitability and availability of feedstock. Karanja and Linseed crops  are abundantly available in India. Biodiesel was produced from a mixture of Karanja and Linseed oils by alkaline transesterification. In this experimental study, biodiesel blends of 10%, 20% and 30% were used with diesel in a diesel engine at a constant speed of 1500 rpm with varying brake powers (loads from 0.5 kW to 3.5kW to evaluate brake thermal efficiency, brake specific fuel consumption,  brake specific energy consumption, exhaust gas temperature, mechanical efficiency, volumetric efficiency, air fuel ratio and smoke opacity. They were compared with diesel and found satisfactory. BTE was found to be  28.76% for B10 at 3.5kW load.  Smoke opacity was also found to be reduced with all blends. Smoke opacity was found to be reduced up to 10.23% for B10 biodiesel blend as compared to that of diesel at 3.5kW. Experimental investigation  has revealed that  biodiesel produced from a mixture of Karanja and Linseed oils can be successfully used in diesel engines without any engine modification  and B10 was found to be an optimum biodiesel blend in terms of brake thermal efficiency. Article History: Received April 14th 2016; Received in revised form June 25th 2016; Accepted

  7. Preparation and Characterization of Keratin Blended Films using Biopolymers for Drug Controlled Release Application

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    2016-08-01

    Full Text Available Keratin solution was separately blended with collagen, gelatin, sericin and starch for films preparation. All the blended films had smooth surfaces without phase separation, except the keratin/starch blend film. The native keratin film showed small particles embedded in all the film surfaces that resulted in them being rough. The structure of the native keratin film changed from beta-sheet to random coil at high blend ratio of other substances. This result increased the dissolution of the films especially the keratin/starch blend. The results relate directly to the decreased thermal stability of this film. However, the changes in structure did not affect the chlorhexidine release pattern. It is possible that the interaction between the drug and blending substances, and the substances to water molecules are the main factor influencing the drug release pattern from the films.

  8. Thermal decomposition analysis of coal-waste sludge and coal-sunflower seed husk blends

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-yan; LI Xiao-qi; LIU Wen-tie; SONG Cheng-yi; WANG Chun-sheng; DONG Qun

    2010-01-01

    The thermal decomposition analysis of coal-pharmaceutical waste sludge,coal-sewage waste sludge blends and coal-sunflower seed husk blends are studied by TG dynamic runs at the heating rate of 20 ℃/min within the temperature range of 25 ℃-900℃.The effect of different kinetic models on the determination of kinetic parameters of thermal decompesition has been investigated.Results show that for coal-pharmaceutical sludge blend,coal-sewage sludge blend and coal-sunflower seed husk blend the optimal model functions are the three-dimensional diffusion reaction,2-dimensional and 3-diemensional nucleation and growth reactions,respectively.The Arrhenius kinetic parameters of the pre-exponential factor and activation energy of blends,as well waste sludge and sunflower seed husk only are proposed.

  9. Effect of Organoclay on Compatibilization, Thermal and Mechanical Properties of Polycarbonate/Polystyrene Blends

    CERN Document Server

    Singh, A K

    2014-01-01

    Pristine and organoclay modified polycarbonate/polystyrene (PC/PS) blends are prepared using melt-mixing technique. These blends are characterized for their morphology, structural, thermal and mechanical properties. Though our FTIR and XRD results show weak interactions between PC and PS phases, however, DSC and morphological study reveals that pristine PC/PS blends are immiscible. On other hand, introduction of organoclay results compatibilization of two polymer phases which is supported by significant shift in glass transition temperatures of the component phases and a distinct morphology having no phase segregation on sub-micron scale. Intercalation of polymers inside the clay gallery is achieved and is supported by XRD studies. A better thermal stability and higher value of modulus of the compatibilized blends compared to pristine PC/PS blends also support the reinforcement effect of organoclay to the PC/PS blend matrix.

  10. Fabrication and Characterization of Electrospun Wool Keratin/Poly(vinyl alcohol Blend Nanofibers

    Directory of Open Access Journals (Sweden)

    Shuai Li

    2014-01-01

    Full Text Available Wool keratin/poly(vinyl alcohol (PVA blend nanofibers were fabricated using the electrospinning method in formic acid solutions with different weight ratios of keratin to PVA. The resultant blend nanofibers were characterized by scanning electron microscopy (SEM, Fourier transform infrared (FTIR, X-ray diffraction (XRD, thermal gravimetric analysis (TGA, and tensile test. SEM images showed that the diameter of the blend nanofibers was affected by the content of keratin in blend solution. FTIR and XRD analyses data demonstrated that there were good interactions between keratin and PVA in the blended nanofibers caused by possibly hydrogen bonds. The TGA study revealed that the thermal stability of the blend nanofibers was between those of keratin and PVA. Tensile test indicated that the addition of PVA was able to improve the mechanical properties of the electrospun nanofibers.

  11. Properties of baked foams from citric acid modified cassava starch and native cassava starch blends.

    Science.gov (United States)

    Pornsuksomboon, Kanlaya; Holló, Berta Barta; Szécsényi, Katalin Mészáros; Kaewtatip, Kaewta

    2016-01-20

    Starch foams from native cassava starch (NS) and citric acid modified cassava starch (CNS) were prepared using baking processes with blend ratios of 80/20, 60/40, 50/50, 40/60 and 20/80. The density, thickness, morphology, thermal stability and water absorption of the NS, CNS and blended starch foams were determined. The ratio of the two starch components had a significant influence on the density and thickness of the blended starch foams. All blended starch foams showed good water resistance. Moreover, the morphology of the blended starch foam with the NS/CNS ratio of 50/50 showed a more ordered distribution of cell sizes with thicker cell walls than for the NS and CNS foams. The thermal stability of the blended starch foams was somewhat lower than the stability of the NS foam but not to the extent that it affected any potential practical applications.

  12. EFFECTS OF BLENDING CHITOSAN WITH PEG ON SURFACE MORPHOLOGY,CRYSTALLIZATION AND THERMAL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Ling-hao He; Rui Xue; De-bin Yang; Ying Liu; Rui Song

    2009-01-01

    Biodegradable blend films composed of chitosan and PEG with various composition ratios were prepared. The chemical structure of the blend films was characterized with FTIR and X-ray, which showed no chemical bond formations but certain interactions probably coming from the hydrogen bonds. Morphologies of these blend films were viewed using AFM and SEM, suggesting that pure chitosan film had a smooth surface structure and the blend films surface showed a plenty of holes with varying size. Through the DMA measurement, it was found that there existed differences in the peak area and position of the blend films, and the peak at the glass transition temperature became significantly weaker and was markedly wider with the increasing content of PEG. The obtained results showed that the crystallinity of chitosan was suppressed and partially destroyed; and this should have an influence on the thermal behaviors and dynamic mechanical properties of the blend films.

  13. An Integrated Methodology for Design of Tailor-Made Blended Products

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza; Gernaey, Krist; Woodley, John

    2012-01-01

    design, 2) process identification, and 3) experimental verification. The principle problem, which is the product design stage is divided into four sub-problems and solved with a decomposition-based approach. In stage two, the ability to produce the chemicals used as building blocks in the blends......A computer-aided methodology has been developed for the design of blended (mixture) products. Through this methodology, it is possible to identify the most suitable chemicals for blending, and “tailor” the blend according to specified product needs. The methodology has three stages: 1) product...... is analyzed. Finally, experimental work (or detailed model-based verification) is conducted in stage three to validate the selected blend candidates. In this study, the product design stage is highlighted through a case study of gasoline blends with bio-based chemicals. The objective of this study...

  14. Physicochemical characterization of chitosan/nylon6/polyurethane foam chemically cross-linked ternary blends.

    Science.gov (United States)

    Jayakumar, S; Sudha, P N

    2013-03-15

    Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components.

  15. Preparation and Characterization of Chitosan/Agar Blended Films: Part 2. Thermal, Mechanical, and Surface Properties

    Directory of Open Access Journals (Sweden)

    Esam A. Elhefian

    2012-01-01

    Full Text Available Chitosan/agar (CS/AG films were prepared by blending different proportions of chitosan and agar (considering chitosan as the major component in solution forms. The thermal stability of the blended films was studied using thermal gravimetric analysis (TGA. It was revealed that chitosan and agar form a compatible blend. Studying the mechanical properties of the films showed a decrease in the tensile strength and elongation at break with increasing agar content. Blending of agar with chitosan at all proportions was found to form hydrogel films with enhanced swelling compared to the pure chitosan one. Static water contact angle measurements confirmed the increasing affinity of the blended films towards water suggesting that blending of agar with chitosan improves the wettability of the obtained films.

  16. Studies on alpha-amylase induced degradation of binary polymeric blends of crosslinked starch and pectin.

    Science.gov (United States)

    Bajpai, A K; Shrivastava, Jyoti

    2007-05-01

    A blend matrix of crosslinked starch and pectin was prepared and characterized by infra-red (IR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The prepared blends were investigated kinetically for water sorption studies and alpha-amylase induced degradation adopting a gravimetric procedure. Based on the experimental findings, a plausible mechanism including both diffusion and surface enhanced degradation was suggested and degradation profiles were interpreted. The influence of various factors such as chemical architecture of the blend, pH and temperature of alpha-amylase solution were examined for the swelling and degradation kinetics of crosslinked starch-pectin blends. The effect of concentration of enzyme solution was also studied on the degradation profile of the blends. A correlation was established between the extent of degradation and water imbibing capacity of the degrading blends.

  17. STUDIES ON SELF-VULCANIZING FLUOROELASTOMER/PHENOL HYDROXY SILICONE RUBBER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Ya-ming Wang; Lan Liu; Yuan-fang Luo; De-min Jia

    2009-01-01

    Self-vulcanizing blends of phenol hydroxy silicone rubber (PHSR) and fluoroelastomer (FPM) were prepared. Vulcanized rubbers with lower glass transition temperature (Tg) were successfully obtained. The results of dynamic mechanical analysis (DMA) show that the vulcanized FPM/PHSR (10 phr) blend has only one Tg temperature, demonstrating the well compatibility between FPM and PHSR. The thermogravimetric analysis (TGA) demonstrates that the PHSR do little damage to the thermal stability of FPM. The vulcanization characteristics of the FPM/PHSR blends were analyzed by using oscillating disc rheometer (ODR). The results show that FPM/PHSR blends have smaller Smin values and longer scorch time than that of FPM with the same level of bisphenol AF curing agent. It means that FPM/PHSR blends have better processability and curing security. Better mechanical properties can be gained for FPM/PHSR blends at appropriate level of PHSR.

  18. A study on the char burnout characteristics of coal and biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Behdad Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, School of Engineering, Faculty of Engineering and Built Environment

    2007-10-15

    The char burnout characteristics of coal/biomass blends under conditions pertinent to pulverised fuel combustors were investigated by a combined modelling and experimental approach. Results indicate that blending of coal with biomass increases the likelihood of char extinction (i.e. extinction potential of the char particle in the blend), in turn, decreasing the char burnout level. Our modelling results attribute this to a reduction in the char particle size to levels below a critical dimension which appears to be a strong function of the fuel blending ratio (the weight percentage of biomass in the blend), fuel reactivity, char cloud shape and particle density number. It is demonstrated here that the drop in the char burnout level during co-firing can be effectively resolved when a more reactive secondary coal is added to the blend to minimise its extinction potential. 22 refs., 8 figs., 2 tabs.

  19. Blended Learning在独立学院教学中的应用研究

    Institute of Scientific and Technical Information of China (English)

    石黎; 杨珂玲; 孙志梅

    2013-01-01

      Blended Learning是人们对传统课堂教学和远程在线学习进行深刻反思后形成的一种学习方式,独立学院教学中可以用Blended Learning来更新计算机辅助教学的运用观念,而优秀的网络教学平台对开展Blended Learning至关重要。本文简要介绍了Moodle网络教学平台以及Blended Learning模式,在此基础上,研究了基于moodle的Blended Learning模式,探讨了在moodle平台上开展Blended Learning的模式构建及实施过程。

  20. Preparation and Characterization of HPMC/PVP Blend Films Plasticized with Sorbitol

    Directory of Open Access Journals (Sweden)

    H. Somashekarappa

    2013-01-01

    Full Text Available The aim of this present work is to investigate the effect of plasticizers like Sorbitol on microstructural and mechanical properties of hydroxypropyl methylcellulose (HPMC and Polyvinylpyrrolidone (PVP blend films. The pure blend and plasticized blend films were prepared by solution casting method and investigated using wide angle X-ray scattering (WAXS method. WAXS analysis confirms that the plasticizers can enter into macromolecular blend structure and destroy the crystallinity of the films. FTIR spectra show that there are a shift and decrease in the intensity of the peaks confirming the interaction of plasticizer with the blend. Mechanical properties like tensile strength and Young’s Modulus decrease up to 0.6% of Sorbitol content in the films. Percentage of elongation at break increases suggesting that the plasticized films are more flexible than pure blend films. These films are suitable to be used as environmental friendly and biodegradable packaging films.