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

    OpenAIRE

    Bauerová, Andrea

    2013-01-01

    This thesis is focused on a new approach of education called blended learning. The history and developement of Blended Learning is described in the first part. Then the methods and tools of Blended Learning are evaluated and compared to the traditional methods of education. At the final part an efficient developement of the educational programs is emphasized.

  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

    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......) 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. 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...

  9. Stockyard blending

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, C.; Grattarola, G.C. (Italimpianti S.p.A., Genoa (Italy). Bulk Materials Handling Division)

    1991-03-01

    Six computer calculation programs have been developed to simulate the blending process. The integrated system, known as ASPO, has been implemented by Italimpianti for statistical analysis of the blending processes in stockyards. Programs are written in FORTRAN 77 and require a short processing time. The OLOMON program analyzes the content percentages; RAILON analyses the ratio indices; the TRAGEO and TRAMIX programs allow the building of the transverse section of the pipe and create data for subsequent analysis of reclaiming the front; TRATAM and TRARUA enable analysis of the reclaiming of the pile with a barrel and a wheel reclaimer respectively. Results of the application of the blending technique in the iron and steel industry in an iron ore plant and in a coal blending plant in the USSR are given. 1 ref., 25 figs., 1 tab.

  10. Blended learning

    OpenAIRE

    Басава, Ганна Іванаўна; Салаўёў, Павел Леанідавіч

    2015-01-01

    In recent years, the training initiatives in blended learning increased enormously as a result of the different demands to integrate the Information and Communication Technologies (ICT) in educational systems. In Higher Education, the blend approach is highly pursued because of its unique flexibility that allows the teacher to propose, in every situation, more advantageous train- ing solutions for their students, contrary to mandatory classroom in Basic and Secondary schools. It seems that th...

  11. Effective Blended Learning Techniques

    Science.gov (United States)

    Gill, Deborah

    2009-01-01

    Blended learning is becoming more prevalent in higher education courses. Reasons for blending range from accommodating more students to improving the quality of courses offered. The purpose of this paper is twofold: (1) to discuss student attitudes towards blended courses versus face-to-face versus completely online courses, and (2) to consider…

  12. Blended learning

    OpenAIRE

    Rubens, Wilfred

    2011-01-01

    `Blended learning` во изучувањето на странските јазици нуди голема предност во споредба со другите методи и пристапи. Како концепт тој вклучува обработка на оригинален текст и негова актуeлизација во процесот на учење во комбинација со интернет или напредната технологија во наставата, но користи и аудио и видео снимки од изворни говорници. Во својата наставна дејност анализирам и обработувам видео и аудио текстови од германски изворни говорители преземени од различни веб страници. На овој нач...

  13. 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…

  14. Blended Learning Design

    DEFF Research Database (Denmark)

    Pedersen, Lise

    2015-01-01

    and Learning Resources (EILR) was asked to develop and support the blended learning implementation strategy. EILR is an inter-faculty unit in UCL, which develops and supports digitization and learning approaches in the professional bachelor programme. The paper addresses the potentials and the pitfalls...... in the blended learning implementation strategy. The blended learning implementation strategy contains phases for preparation, development, implementation and evaluation. The preparation phase addresses the importance of goal-setting and includes the winnings and the purpose. The developmental phase looks......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...

  15. Blended Learning Environments and Suggesstions for Blended Learning Design

    OpenAIRE

    Dağ, Funda

    2011-01-01

    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 b...

  16. 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.

  17. 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...

  18. Theory of polymer blends

    International Nuclear Information System (INIS)

    We have recently developed a new theoretical approach to the study of polymer liquids. The theory is based on the ''reference interaction site model'' (RISM theory) of Chandler and Andersen, which has been successful in describing the structure of small molecule liquids. We have recently extended our polymer RISM theory to the case of polymer blends. In the present investigation we have applied this theory to two special binary blends: (1) the athermal mixture where we isolate structural effects, and (2) the isotopic mixture in which structurally identical polymer chains interact with dissimilar attractive interactions. By studying these two special cases we are able to obtain insights into the molecular factors which control the miscibility in polymer mixtures. 18 refs., 2 figs

  19. Multi-model blending

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. 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.

  1. 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 ...

  2. 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.

  3. 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....

  4. 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. PMID:26317458

  5. 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…

  6. 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…

  7. 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…

  8. Viscoelastic Properties of Polymer Blends

    Science.gov (United States)

    Hong, S. D.; Moacanin, J.; Soong, D.

    1982-01-01

    Viscosity, shear modulus and other viscoelastic properties of multicomponent polymer blends are predicted from behavior of individual components, using a mathematical model. Model is extension of two-component-blend model based on Rouse-Bueche-Zimm theory of polymer viscoelasticity. Extension assumes that probabilities of forming various possible intracomponent and intercomponent entanglements among polymer molecules are proportional to relative abundances of components.

  9. Challenges of blended-learning

    OpenAIRE

    Lugovtsova, Y. D.; Mylnikova, Tatyana Stepanovna

    2014-01-01

    Creation of the virtual environment as an educational resource to increase motivation and inquisition of the students is a great challenge for Russian educational system. The paper considers some issues of blended-learning. Some elements of blended-learning are analyzed through the ways they are implemented in Tomsk Polytechnic University.

  10. 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

  11. 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.

  12. 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.

  13. 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...

  14. 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.

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

    OpenAIRE

    Mehmet A Ocak

    2010-01-01

    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, ...

  16. 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.

  17. 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.

  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. 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...

  20. 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.

  1. Radiation effect on PVC/ENR blends

    International Nuclear Information System (INIS)

    The effect of irradiation on the physical properties of Polyvinyl Chloride / Epoxidised Natural Rubber Blends (PVC/ENR blends) were investigated. The enhancement in tensile strength, elongation at break, hardness and aging properties of the blends have confirmed the positive effect of irradiation on the blends. It is evident from gel fraction and infra red spectroscopic studies that the blends of PVC and ENR cross-linked upon irradiation. The results also revealed that at any blend composition, the enhancement in properties depend on irradiation dose which controls the degree of radiation induced cross-linking. In an attempt to maximize the constructive effect of irradiation, the influence of various additives such as stabilizers, radiation sensitizers, fillers and processing aids on the blend properties were studied. The changes in blend properties upon irradiation with the presents of above additives were also presented in this paper

  2. 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…

  3. Laboratory optimization of continuous blend asphalt rubber

    OpenAIRE

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Trichês, Glicério; Pais, Jorge C.; Luzia, Rosa

    2008-01-01

    Asphalt rubber from wet process requires batching blending and reaction time associated to blending rubber and conventional asphalt to produce asphalt rubber. The ideal blending of these materials depends on the combination of very important variables, such as the amount of rubber, reaction time and temperature reaction. This paper intends to optimize the laboratory production of asphalt rubber using the continuous blend process. The rubber from waste tyres was reduced by ambient grinding and...

  4. Binary blend nanoparticles with defined morphology

    OpenAIRE

    Ghazy, Omayma

    2008-01-01

    In this study polymer blends of polystyrene and poly(propylene carbonate) were prepared using the miniemulsion process as model systems for the nanoparticles consisting of semiconducting polymers for optical applications. The blends were prepared by mixing nanoparticles of pure polymers or by fabricating blend nanoparticles including both the two polymers in each particle. The development of controlled hemispherical phase separated morphology (Janus morphology) within the blend nanoparticles ...

  5. Performance of Blended Learning in University Teaching:

    OpenAIRE

    Michael Reiss; Dirk Steffens

    2010-01-01

    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 perf...

  6. 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....

  7. Towards generating novel games using conceptual blending

    OpenAIRE

    Gow, Jeremy; Corneli, Joseph

    2015-01-01

    We sketch the process of creating a novel video game by blending two video games specified in the Video Game Description Language (VGDL), following the COINVENT computational model of conceptual blending. We highlight the choices that need to be made in this process, and discuss the prospects for a computational game designer based on blending.

  8. 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...

  9. 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…

  10. 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.

  11. Confined flow of polymer blends.

    Science.gov (United States)

    Tufano, C; Peters, G W M; Meijer, H E H

    2008-05-01

    The influence of confinement on the steady-state morphology of two different emulsions is investigated. The blends, made from polybutene (PB) in polydimethylsiloxane (PDMS) and polybutadiene (PBD) in PDMS, are sheared between two parallel plates, mostly with a standard gap spacing of 40 microm, in the range of shear rates at which the transition from "bulk" behavior toward "confined" behavior is observed. For both cases, the influence of the concentration was systematically investigated, as well as the shear rate effects on the final steady-state morphology. By decreasing the shear rate, for each blend, the increasing droplets, i.e., increasing confinement for a fixed gap spacing, arrange themselves first into two layers, and when the degree of confinement reaches an even higher value, a single layer of droplets is formed. The ratio between the drop diameters and the gap spacing at which this transition occurs is always lower than 0.5. While decreasing the shear rate, the degree of confinement increases due to drop coalescence. Droplets arrange themselves in superstructures like ordered pearl necklaces and, at the lower shear rates, strings. The aspect ratio and the width of the droplet obtained from optical micrographs are compared to predictions of the single droplet Maffettone-Minale model (MM model(1)). It is found that the theory, meant for unconfined shear flow, is not able to predict the drop deformation when the degree of confinement is above a critical value that depends on the blends considered and the shear rate applied. A recently developed extension of the MM model is reported by Minale (M model(2)) where the effect of the confinement is included by using the Shapira-Haber correction.3 Further extending this M model, by incorporating an effective viscosity as originally proposed by Choi and Showalter,4 we arrive at the mM model that accurately describes the experiments of blends in confined flow. PMID:18348582

  12. 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......  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.......,  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....

  13. 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.

  14. Miscibility evolution of polycarbonate/polystyrene blends during compounding

    DEFF Research Database (Denmark)

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

    2002-01-01

    The miscibility evolution of polycarbonate/polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, remelt blending in a twin-screw extruder and third melt blending in an injection molding machine, was investigated by...

  15. Rheological properties of olefinic thermoplastic elastomer blends

    OpenAIRE

    Sengers, W.G.F.

    2005-01-01

    Thermoplastic Elastomers (TPE) are a class of materials that have rubber-like properties and can be processed like thermoplastic polymers. In this thesis, the rheological properties of two TPE blends are correlated to their morphology. The thermoplastic vulcanisates (TPV) consist of micron-sized, cured elastomer particles while the blends of PP and the triblock copolymer SEBS show co-continuous structures. Both blends also contain considerable amount of paraffinic oil. The difference between ...

  16. A Time Based Blended Learning Model

    OpenAIRE

    Norberg, Anders; Dziuban, Charles D; Moskal, Patsy M

    2011-01-01

    Purpose – This paper seeks to outline a time-based strategy for blended learning that illustrates course design and delivery by framing students' learning opportunities in synchronous and asynchronous modalities. Design/methodology/approach – This paper deconstructs the evolving components of blended learning in order to identify changes induced by digital technologies for enhancing teaching and learning environments. Findings – This paper hypothesizes that blended learning may be traced back...

  17. Constructivism Based Blended Learning in Higher Education

    OpenAIRE

    Ahmad Mhammad Al-Huneidi; Jeanne Schreurs

    2012-01-01

    This paper explain how to apply Constructivism and Conversation theories in Blended Learning environment in order to increase learning outcomes and quality. Some scenarios of Constructivism based blended learning activities are presented in this paper. In addition, a Constructivism Based Blended Learning model for “ICT Management†course, a compulsory course in Master of Management Information Systems program at Hasselt University, is proposed. The proposed model applies and combines Const...

  18. ASP, Amalgamation and the Conceptual Blending Workflow

    OpenAIRE

    Eppe, Manfred; Maclean, Ewen; Confalonieri, Roberto; Kutz, Oliver; Schorlemmer, Marco; Plaza, Enric

    2015-01-01

    We present an amalgamation technique used for conceptual blending – a concept invention method that is advocated in cognitive science as a fundamental, and uniquely human engine for creative thinking. Herein, we employ the search capabilities of ASP to find commonalities among input concepts as part of the blending process, and we show how our approach fits within a generalised conceptual blending workflow. Specifically, we orchestrate ASP with imperative programming languages like Python, to...

  19. 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.

  20. Sludge Stabilization Campaign blend plan

    Energy Technology Data Exchange (ETDEWEB)

    De Vries, M.L.

    1994-10-04

    This sludge stabilization blend plan documents the material to be processed and the order of processing for the FY95 Sludge Stabilization Campaign. The primary mission of this process is to reduce the inventory of unstable plutonium bearing sludge. The source of the sludge is residual and glovebox floor sweepings from the production of material at the Plutonium Finishing Plant (PFP). The reactive sludge is currently being stored in various gloveboxes at PFP. There are two types of the plutonium bearing material that will be thermally stabilized in the muffle furnace: Plutonium Reclamation Facility (PRF) sludge and Remote Mechanical C (RMC) Line material.

  1. STUDENTS’ OPINIONS ON BLENDED LEARNING

    OpenAIRE

    BALCI, Meric; SORAN, HALUK

    2009-01-01

    E-learning was acknowledged by most educators and researchers as a savior, even an only alternative in education field, especially in the following years of its emergence. However, with the rise of its limitations, the idea of bringing face-to-face learning and e-learning together to complete each other has occured. Blended learning is a method emerged as a result of this sentiment. The new education alternatives which have been discovered as a consequence of the researches and the studies ma...

  2. Custom blending of lamp phosphors

    Science.gov (United States)

    Klemm, R. E.

    1978-01-01

    Spectral output of fluorescent lamps can be precisely adjusted by using computer-assisted analysis for custom blending lamp phosphors. With technique, spectrum of main bank of lamps is measured and stored in computer memory along with emission characteristics of commonly available phosphors. Computer then calculates ratio of green and blue intensities for each phosphor according to manufacturer's specifications and plots them as coordinates on graph. Same ratios are calculated for measured spectrum. Once proper mix is determined, it is applied as coating to fluorescent tubing.

  3. 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.

  4. 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...

  5. PAIRWISE BLENDING OF HIGH LEVEL WASTE

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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…

  8. 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.

  9. 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…

  10. Perspectives on Blended Learning in Higher Education

    Science.gov (United States)

    Vaughan, N.

    2007-01-01

    This article explores the benefits and challenges of blended learning in higher education from the perspective of students, faculty, and administration that have had direct experience with this form of course delivery. Students indicate that a blended learning model provides them with greater time flexibility and improved learning outcomes but…

  11. Dynamic Heterogeneity in Interacting Miscible Polymer Blends

    Science.gov (United States)

    Gaikwad, Ashish; Lodge, Timothy

    2008-03-01

    Dynamic heterogeneity leading to time-temperature superposition (tTS) failure has been widely reported in non-interacting/weakly interacting miscible polymer blends. However, coupling of the component dynamic response in blends, even with a huge dynamic asymmetry in the pure components, is possible with H-bonding interactions. This study is focused on finding the minimum level of interaction necessary for thermo-rheological simplicity in blends. Blends of styrene-co-vinylphenol (PSVPh) and poly(vinyl methyl ether) (PVME) were chosen. Incorporation of styrene provides an effective way to modulate H-bonding interactions in the system. Linear viscoelastic data indicate that tTS fails for PS/PVME blends, whereas data obtained for different PVPh/PVME blends showed that tTS was obeyed a over wide temperature range. For PSVPh/PVME blends with low PSVPh content, tTS was successful. This suggests that the presence of alternating styrene and vinyl phenol units was insufficient for dynamic response decoupling. Further studies are in progress, with varying vinyl phenol content in PSVPh, to explore the influence of H-bonding on dynamic heterogeneity and blend dynamics.

  12. 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...

  13. Green emitting phosphors and blends thereof

    Science.gov (United States)

    Setlur, Anant Achyut; Siclovan, Oltea Puica; Nammalwar, Prasanth Kumar; Sathyanarayan, Ramesh Rao; Porob, Digamber G.; Chandran, Ramachandran Gopi; Heward, William Jordan; Radkov, Emil Vergilov; Briel, Linda Jane Valyou

    2010-12-28

    Phosphor compositions, blends thereof and light emitting devices including white light emitting LED based devices, and backlights, based on such phosphor compositions. The devices include a light source and a phosphor material as described. Also disclosed are phosphor blends including such a phosphor and devices made therefrom.

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

    DEFF Research Database (Denmark)

    Yunus, Nor Alafiza Binti

    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...... 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...... library. Thirdly, a mixture/blend design algorithm is applied to obtain the mixtures/blends that match the design targets. The result is a set of blends that match the constraints, the composition of the chemicals present in the blend, and the values of the target properties. Finally, the mixture target...

  15. 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.

  16. 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.

  17. 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.

  18. Segmentation and Representation of Consonant Blends in Kindergarten Children's Spellings

    Science.gov (United States)

    Werfel, Krystal L.; Schuele, C. Melanie

    2012-01-01

    Purpose: The purpose of this study was to describe the growth of children's segmentation and representation of consonant blends in the kindergarten year and to evaluate the extent to which linguistic features influence segmentation and representation of consonant blends. Specifically, the roles of word position (initial blends, final blends),…

  19. 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..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit...

  20. 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...

  1. 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.

  2. 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...

  3. Hyperspectral imaging of polymer/fullerene blends

    Science.gov (United States)

    Torreggiani, Armida; Tinti, Francesca; Savoini, Alberto; Melchiorre, Michele; Po, Riccardo; Camaioni, Nadia

    2014-10-01

    The effectiveness of a hyperspectral imaging system integrated on an enhanced dark-field microscope for probing the microscale morphology of model poly(3- hexylthiopene): [6,6]-phenyl-C61- butyric acid methyl ester (P3HT:PCBM) blends is demonstrated. This non-contact technique provides both spectral and spatial information in one measurement, providing an effective mapping of the presence and location of the component materials in the investigated P3HT:PCBM blends spincoated over different substrates (zinc oxide, poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate). The hyperspectral analysis accounts for the micro-scale morphology of P3HT:PCBM blends, even in case of high film roughness, and the quantitative determination of blend components reveals a preferential accumulation of the lowenergy material (P3HT) at the interface with air, confirming the findings reported with other mapping techniques

  4. Enzymatic degradation of polycaprolactone-gelatin blend

    Science.gov (United States)

    Banerjee, Aditi; Chatterjee, Kaushik; Madras, Giridhar

    2015-04-01

    Blends of polycaprolactone (PCL), a synthetic polymer and gelatin, natural polymer offer a optimal combination of strength, water wettability and cytocompatibility for use as a resorbable biomaterial. The enzymatic degradation of PCL, gelatin and PCL-gelatin blended films was studied in the presence of lipase (Novozym 435, immobilized) and lysozyme. Novozym 435 degraded the PCL films whereas lysozyme degraded the gelatin. Though Novozym 435 and lysozyme individually could degrade PCL-gelatin blended films, the combination of these enzymes showed the highest degradation of these blended films. Moreover, the enzymatic degradation was much faster when fresh enzymes were added at regular intervals. The changes in physico-chemical properties of polymer films due to degradation were studied by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. These results have important implications for designing resorbable biomedical implants.

  5. 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...

  6. Prospects of Blended Learning Implementation at Technical University

    OpenAIRE

    Buran, Anna Leonidovna; Evseeva, Arina Mikhailovna

    2015-01-01

    The present paper explores the integration of a blended learning course in the process of learning English as a second language at the technical university. We overview the difference between traditional, web facilitated, blended learning and online course; the implementation of the blended learning course in the process of learning English at the technical university. The article also investigates the benefits and drawbacks of blended learning and the possibilities of a blended learning cour...

  7. Blended Learning-A Focus Study on Asia

    OpenAIRE

    Kwong Onn Tham; ChoiKit Tham

    2011-01-01

    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 ...

  8. Film formation from latex blends

    Science.gov (United States)

    Tang, Jiansheng

    2000-10-01

    Film formation from hard/soft (i.e., high Tg/low Tg) latex blends consisting of hard polystyrene (PS) and soft poly(n-butyl methacrylate-co-n-butyl acrylate) [P(BMA/BA)] latex particles were studied with an emphasis on the influence of the carboxyl groups present on the latex particles. A theoretical model was developed to calculate the optimal surfactant and monomer feed rates for a semicontinuous polymerization process to synthesize monodisperse carboxylated latex particles and independently control the particle size and degree of carboxylation. An important finding obtained from the drying studies is that the drying rate from the edge zone is much faster than the rate obtained from the latex pool. It was also found that the presence of carboxyl groups on the latex particles retarded the drying rate. Utilizing PS particles with a low density of carboxyl groups present on the particle surfaces (e.g., 10% surface coverage) resulted in an even distribution of these particles in the soft copolymer matrix, and thus, good film gloss was achieved. However, the use of hard particles with a high density of carboxyl groups present (e.g., 65% coverage) resulted in a less even distribution of PS particles and poor gloss. A cluster model and a hydrogen bonding mechanism were proposed to explain these phenomena. The presence of the carboxyl groups on the PS particles significantly enhanced the Young's modulus and the yield strength, but did not influence the ultimate mechanical properties. A quantitative model was proposed to predict the Young's modus of the latex blend films as a function of the carboxyl group coverage on the hard particles. There was a good fit between model and the experimental data. The stability of the precipitated calcium carbonate (PCC) particles in the P(BMA/BA) latexes was determined by the charge on pigment surface which, in turn, was influenced by the presence of sodium polyacrylate stabilizer. It was found that the wetting ability of the soft

  9. Blended Learning in International Nuclear Education

    International Nuclear Information System (INIS)

    The spread of nuclear power ambitions beyond the few early-adopter nations requires more globalized education. Two of the learning problems specific to international education are the need for a common instructional language and different cultural styles of learning. Blended learning, a mix of personal interaction between teacher and impersonal computer-based learning, can solve these problems. The new KEPCO International Nuclear Graduate School outside Ulsan, Korea is investing heavily in blended learning

  10. Constructivism Based Blended Learning in Higher Education

    OpenAIRE

    Al-Huneidi, Ahmad

    2011-01-01

    Blended Learning, which is a mix of online and face-to-face learning, can combine the benefits of both, traditional classroom learning and e-learning environments.3 The aim of this thesis is to explore how to design and implement Blended Learning environment based on Constructivism theory, which focuses on students’ experience to construct the knowledge, in order to increase learning outcomes, performance, and quality in academic institutions. An affective and successful learni...

  11. Blending of polyethylene materials for pipe applications

    OpenAIRE

    Wright, Wayne Clifton Augustus

    1989-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Melt blending of polyethylene, in particularly HDPE and LLDPE, have been shown to be a major success, especially in the film markets. In this thesis studies are reported on the stress rupture performance of pipes produced from selected polyethylene materials blended to a chosen MDPE pipe grade. The pipes were tested, notched or unnotched, at a single temperature of 80oC and at internal pressu...

  12. Surface segregation of conformationally asymmetric polymer blends

    OpenAIRE

    Stepanow, Semjon; Fedorenko, Andrei A.

    2005-01-01

    We have generalized the Edwards' method of collective description of dense polymer systems in terms of effective potentials to polymer blends in the presence of a surface. With this method we have studied conformationally asymmetric athermic polymer blends in the presence of a hard wall to the first order in effective potentials. For polymers with the same gyration radius $R_g$ but different statistical segment lengths $l_{A}$ and $l_{B}$ the excess concentration of stiffer polymers at the su...

  13. Physical Aging of Miscible Polymer Blends

    OpenAIRE

    Robertson, Christopher

    1999-01-01

    Physical aging measurements were performed on various polymeric glasses with the overriding goal of developing a better molecular picture of the nonequilibrium glassy state. To this end, aging-induced changes in mechanical properties and in the thermodynamic state (volume and enthalpy) were assessed for two different miscible polymer blends as a function of both composition and aging temperature. This investigation considered the physical aging behavior of blends containing atactic polystyr...

  14. Interfacial Slip in Sheared Polymer Blends

    OpenAIRE

    Lo, Tak Shing; Mihajlovic, Maja; Shnidman, Yitzhak; Li, Wentao; Gersappe, Dilip

    2004-01-01

    We have developed a dynamic self-consistent field theory, without any adjustable parameters, for unentangled polymer blends under shear. Our model accounts for the interaction between polymers, and enables one to compute the evolution of the local rheology, microstructure and the conformations of the polymer chains under shear self-consistently. We use this model to study the interfacial dynamics in sheared polymer blends and make a quantitative comparison between this model and Molecular Dyn...

  15. 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 o...... and ongoing research in developing Blended Interaction spaces for collaborative design. We then identify key themes and challenges pertinent for the workshop....

  16. Blended learning approaches enhance student academic performance

    OpenAIRE

    Morris, NP

    2010-01-01

    Blended learning, or technology enhanced learning, is increasingly becoming an expectation for higher education students. Blended learning allows for the enhancement of face-to-face interaction between tutors and students, using internet or computer based tools. In this paper, a range of case studies are described which illustrate methods to engage students with technology enhanced learning and improve academic performance and student satisfaction. In the first case study, first year undergra...

  17. Redesigning A Course For Blended Learning Environment

    OpenAIRE

    Orhan, Feza

    2008-01-01

    ABSTRACT This article describes a collaborative study of the blended learning approach, designed to pave the way for higher education students to integrate online and face-to-face learning environments in an “Instructional Technology and Material Development” course at the University of Yildiz Technic in Turkey. The purpose of this study is to investigate the students’ perceptions of the blended learning environment and to trace the integration between online and face-to-face learning environ...

  18. 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.

  19. Microstructural blending of coal to enhance flowability

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Chakra, H.; Tuezuen, U. [Surrey Univ., Guildford (United Kingdom). Dept. of Chemical and Process Engineering

    2000-09-11

    Coal-fired power stations for electricity generation are well known to suffer from chronic problems in coal handling and flow affecting the operation of pulverisation mills and combustors. The economic impact of coal handling facilities can be significant, resulting in total shutdown of the power generating plant in some extreme cases. In coal-fired power generation, optimal operation of the combustors requires the ash content of pulverised coal not exceed 20%. Excessive ash content would result in lower calorific value. Therefore, the overall profitability of the market coal tends to be strongly effected by the ash content of the raw coal. However, the flowability of coal tends to be strongly affected by the moisture content of the constituent particles, as well as the presence of high fines fraction. The experimental work described in this paper aims to illustrate how flowability can be enhanced by optimising particle size distribution and particle surface moisture in blends of raw and washed coals. The results of the flowability tests obtained with ''microstructurally'' blended samples indicate that to ensure flowability in process vessels, it is necessary to blend according to important microstructural criteria as well as minimising ash content. Microstructural blending is not included in current industrial practice, which only blends washed and raw coals to produce high calorific value and low ash content. The work presented here establishes methodology for microstructural blending to enhance bulk flowability. (orig.)

  20. Sulfur meter speeds coal blending

    International Nuclear Information System (INIS)

    The sulfur content has become the most important criterion that industry looks at when purchasing coal. The exact amount of sulfur in coal being processed by a preparation plant must be known and, if possible, controlled by blending coal streams of various sulfur contents. Present techniques, however, of measuring the sulfur in coal involve laborious and time-consuming sampling and chemical analysis (12 to 24 hr), and the results usually are not available until the following day. By then, the coal barges or trains are already on the way to their destinations. A new nuclear sulfur meter is expected to overcome these difficulties and help lead to true automation in coal preparation plants. Initially developed by the Bureau of Mines' Morgantown Energy Research Center (MERC) at Morgantown, W. Va., and completed after reorganization of the center by the US Energy Research and Development Administration (ERDA), the meter can scan coal to produce a reading within 2 min to an accuracy of 0.04 percent sulfur. The meter is expected to soon result in an element-ash-moisture-Btu meter that would rapidly detect the sulfur, sodium, potassium, and overall mineral content of the coal, as well as its ash and Btu content

  1. 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,…

  2. 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.

  3. 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.

  4. Designed blending for near infrared calibration.

    Science.gov (United States)

    Scheibelhofer, Otto; Grabner, Bianca; Bondi, Robert W; Igne, Benoît; Sacher, Stephan; Khinast, Johannes G

    2015-07-01

    Spectroscopic methods are increasingly used for monitoring pharmaceutical manufacturing unit operations that involve powder handling and processing. With that regard, chemometric models are required to interpret the obtained spectra. There are many ways to prepare artificial powder blend samples used in a chemometric model for predicting the chemical content. Basically, an infinite number of possible concentration levels exist in terms of the individual components. In our study, design of experiments for ternary mixtures was used to establish a suitable number of blend compositions that represents the entire mixture region of interest for a three component blend. Various experimental designs and their effect on the predictive power of a chemometric model for near infrared spectra were investigated. It was determined that a particular choice of experimental design could change the predictive power of a model, even with the same number of calibration experiments. PMID:25980978

  5. 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 also...... compared. The van der Waals equation of state was recently shown to accurately correlate and predict vapor-liquid and liquid-liquid equilibria for binary polymer/solvent solutions. In this work, it is demonstrated that it correlates the upper critical solution behavior of polymer blends with excellent......, the upper critical solution temperature can be predicted with an average error of less than 45 degrees C. The van der Waals equation of state can correlate the lower critical solution behavior of polymer blends, using an interaction parameter that is a linear function of temperature. The UNIFAC and Entropic...

  6. 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.

  7. Learning Design Development for Blended Learning

    DEFF Research Database (Denmark)

    Hansen, Janne Saltoft

    Learning design development for blended learning We started implementing Blackboard at Aarhus University in 2013. At the Health Faculty Blackboard replaced AULA which was a LMS with functionality for file distribution and only a vague focus on learning tools. Most teachers therefore had...... no experiences with blended leaning and technology supported out-of-class activities. At the pedagogical unit at the Health faculty we wanted to follow the Blackboard implementation with pedagogical tools for learning design to evolve the pedagogical use of the system. We needed to make development of blended...... learning courses easier for the teachers and also ensure quality in the courses. This poster describes the process from development of the learning design to implementation of the learning design at the faculty: 1. How to place demands on a learning design-model and how to develop and use such a model. 2...

  8. 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.

  9. 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

  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......, it is shown how to set up parametric acceptance criteria for the batch that gives a high confidence that future samples with a probability larger than a specified value will pass the USP threeclass criteria. Properties and robustness of proposed changes to the USP test for content uniformity are investigated...

  11. 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.

  12. Blended Learning or E-learning?

    OpenAIRE

    Tayebinik, Maryam; Puteh, Marlia

    2013-01-01

    ICT or Information and Communication Technology has pervaded the fields of education.In recent years the term e-learning has emerged as a result of the integration of ICT in the education fields. Following the application this technology into teaching, some pitfalls have been identified and this have led to the Blended learning phenomenon.However the preference on this new method has been debated quite extensively.The aim of this paper is to investigate the advantages of blended learning over...

  13. 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.

  14. 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...

  15. 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...

  16. To blend or not to blend?! That’s the e-learning question!

    OpenAIRE

    Gil, Henrique

    2009-01-01

    This paper aims to discuss and reflect about the importance of blended learning. Today blended learning became very popular but it is important find the best ways and the best types to deliver and ”consume ”it. It is common recognize blended learning as a mix of media and delivery. However there is very important to find out the “right mix” because it is known that different problems need different solutions. When we talk about higher education we deal with adults and we assume that students ...

  17. 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.

  18. 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.

  19. 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.

  20. Blended learning in Saudi universities: challenges and perspectives

    OpenAIRE

    Alebaikan, Reem; Troudi, Salah

    2011-01-01

    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 learning in Saudi higher education are addressed. One major challenge to be considered in the implementation of blended learning in Saudi universitie...

  1. 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…

  2. 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…

  3. Blended Course Design: A Synthesis of Best Practices

    Science.gov (United States)

    McGee, Patricia; Reis, Abby

    2012-01-01

    Blended or hybrid course offerings in higher education are commonplace and much has been written about how to design a blended course effectively. This study examines publically available guides, documents, and books that espouse best or effective practices in blended course design to determine commonalities among such practices. A qualitative…

  4. 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.

  5. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    International Nuclear Information System (INIS)

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation

  6. From E-learning to Blended Learning

    DEFF Research Database (Denmark)

    Hansen, Line Skov; Hansen, Ole

    2013-01-01

    . The project uses a ?capacity building strategy where new practice and skills are built through pedagogical interventions mostly designed as courses based on blended learning with a dialogue oriented and practice related team-work as an important part. Through this work the team learns how to use a specific...

  7. 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

  8. 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.

  9. 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.…

  10. 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…

  11. 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,…

  12. 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.

  13. Rheological properties of olefinic thermoplastic elastomer blends

    NARCIS (Netherlands)

    Sengers, W.G.F.

    2005-01-01

    Thermoplastic Elastomers (TPE) are a class of materials that have rubber-like properties and can be processed like thermoplastic polymers. In this thesis, the rheological properties of two TPE blends are correlated to their morphology. The thermoplastic vulcanisates (TPV) consist of micron-sized, cu

  14. Comparative Blended Learning Practices and Environments

    Science.gov (United States)

    Ng, Eugenia M. W., Ed.

    2010-01-01

    With the advent of new technologies, more convenient and effective ways of learning are being adopted. However, despite the growing advancements there remains a lack of literature in applications of using these technology teaching approaches. This book offers in-depth analysis of new technologies in blended learning that promote creativity,…

  15. Evaluating What Works in Blended Learning

    Science.gov (United States)

    Education Week, 2012

    2012-01-01

    Blended learning--the mix of virtual education and face-to-face instruction--is evolving quickly in schools across the country, generating a variety of different models. This special report, the second in a three-part 2012-13 series on virtual education, examines several of those approaches and aims to identify what is working and where…

  16. Scientific Writing: A Blended Instructional Model

    Science.gov (United States)

    Clark, MaryAnn; Olson, Valerie

    2010-01-01

    Scientific writing is composed of a unique skill set and corresponding instructional strategies are critical to foster learning. In an age of technology, the blended instructional model provides the instrumental format for student mastery of the scientific writing competencies. In addition, the course management program affords opportunities for…

  17. 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.

  18. 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

  19. 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

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

    OpenAIRE

    Nuray Gedik; Ercan Kiraz; M.Yaşar ÖZDEN

    2012-01-01

    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 textural...

  1. 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.

  2. Style: A Computational and Conceptual Blending-Based Approach

    Science.gov (United States)

    Goguen, Joseph A.; Harrell, D. Fox

    This chapter proposes a new approach to style, arising from our work on computational media using structural blending, which enriches the conceptual blending of cognitive linguistics with structure building operations in order to encompass syntax and narrative as well as metaphor. We have implemented both conceptual and structural blending, and conducted initial experiments with poetry, including interactive multimedia poetry, although the approach generalizes to other media. The central idea is to generate multimedia content and analyze style in terms of blending principles, based on our finding that different principles from those of common sense blending are often needed for some contemporary poetic metaphors.

  3. 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.

  4. 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.

  5. TIME-DEPENDENT MORPHOLOGY OF POLYETHYLENE-POLYPROPYLENE BLENDS

    Institute of Scientific and Technical Information of China (English)

    Jun Li; Robert A.Shanks; Long Yu

    2002-01-01

    The effect of time-temperature treatment on morphology of polyethylene-polypropylene (PE-PP) blends wasstudied to establish a relationship between thermal history, morphology and mechanical properties. Polypropylene (PP)homopolymers were used to blend with various polyethylenes (PE), including high density polyethylene (HDPE), lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE), and very and ultra low density polyethylene(VLDPE and ULDPE). The majority of the blends were prepared at a ratio ofPE:PP = 80:20, while blends of PP and LLDPEwere prepared at various compositions. Thermal treatment was carried out at temperatures between the crystallizationtemperatures of PP and PEs to allow PP to crystallize first from the blends. On cooling further, PE crystallized too. A verydiffuse PP spherulite morphology in the PE matrix was formed in some partially miscible blends when PP was less than 20%by mass. Droplet-matrix structures were developed in other blends with either PP or PE as dispersed domains in a continuousmatrix, depending on the composition ratio. The scanning electron microscopy (SEM) images displayed a fibrillar structureof PP spherulite in the LLDPE-PP (80:20) and large droplets of PP in the HDPE-PP (80:20) blend, providing larger surfacearea and better bonding in the LLDPE-PP (80:20) blends. This explains why the blends with diffuse spherulite morphologyshowed greater improvement in tensile properties than droplet-matrix morphology blends after time-temperature treatment.

  6. 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.

  7. Engaging with blended learning to improve students' learning outcomes

    Science.gov (United States)

    Francis, Rebecca; Shannon, Susan J.

    2013-08-01

    When blended learning is embraced to enhance learning in engineering (architectural), design and architecture, we argue it is a best-practice instructional mode. Blended learning is the seamless amalgamation of carefully selected online modules with face-to-face instruction. This paper evaluates case studies of the introduction of blended learning in these disciplines. It demonstrates that students who do not engage with blended learning are academically disadvantaged. Alignment of the blended mode of delivery and the mode of assessment is next considered. Two case studies of the introduction of blended modes of assessment, for improved student satisfaction with feedback, are evaluated. Finally, the reliance upon non-faculty to provide both blended learning and assessment is evaluated using qualitative research methods to establish the barriers to adoption of what is now considered best educational practice.

  8. 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.

  9. Methanol gasoline blend from petroleum coke sources

    Energy Technology Data Exchange (ETDEWEB)

    Netzer, David [Consulting Chemical Engineer (United States); Wallsgrove, Chris [Process Engineering Manager (United States)

    2011-07-01

    In Alberta, a large amount of petroleum coke is produced as a byproduct from processes relating to bitumen upgrading and refining. Unfortunately, there is little to no market for this product in the province. This presentation addresses concerns relating to the concept of converting the otherwise wasted petcoke into methanol and using it as a blending component in gasoline. The presentation tackles issues relating to environmental impact, economics, renewability, toxicity, safety, and vehicle design by analyzing and comparing the proposed methanol/gasoline (M-10) to that of an ethanol/gasoline (E-10). The presentation covers analysis of the CO2 emissions, an analysis of the finances, and a number of scenarios involving the improper use or accidental spillage of M-10. Through the comparison of methanol/gasoline and ethanol/gasoline, the presentation demonstrated that converting the petcoke byproduct into methanol for use as a gasoline blend is a viable option.

  10. Guidelines for handling and blending FAME

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-11-15

    This report provides guidance on the handling and blending of Fatty Acid Methyl Esters (FAME), as a neat product and at concentrations up to 10% v/v in diesel fuel. The major challenges associated with diesel fuels containing FAME are discussed as they relate to the conformity of the finished fuel to typical specifications, especially those in the European standard for automotive diesel (EN 590). This report focuses on the production, blending, distribution, and supply of diesel containing up to 10% v/v FAME as well as the storage and handling of neat FAME but does not address vehicle-related issues with the use of diesel fuels containing FAME. The potential future production and use of Fatty Acid Ethyl Esters (FAEE) in diesel fuel is also discussed.

  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. Polymer blend compositions and methods of preparation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. A Multimodal Interaction Framework for Blended Learning

    DEFF Research Database (Denmark)

    Vidakis, Nikolaos; Kalafatis, Konstantinos; Triantafyllidis, Georgios

    2016-01-01

    of communication with an application, which will be more natural than the traditional “windows, icons, menus, pointer” (WIMP) style. Despite the great amount of devices in existence, most applications make use of a very limited set of modalities, most notably speech and touch. This paper describes a multimodal...... framework enabling deployment of a vast variety of modalities, tailored appropriately for use in blended learning environment....

  14. 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.

  15. Characterization of polymer-liquid crystal blends

    OpenAIRE

    DOINA MACOCINSCHI; CRISTOFOR I. SIMIONESCU; DANIELA FILIP

    2001-01-01

    Blends of semi-crystalline polymers (polyethylene adipate and two poly(ester-urethane) s) with liquid crystal cholesteryl palmitate with different compositions were prepared by solution casting. One of the poly(ester-urethane)s was based on 2,4-tolylene diisocyanate (TDI) and the other one on 4,4-diphenylmethane diisocyanate (MDI). The miscibility and phase transition were investigated over the whole range of concentration by differential scanning calorimetry and polarizing optical microscopy.

  16. Phase Segregation in Polystyrene?Polylactide Blends

    OpenAIRE

    Leung, Bonnie

    2011-01-01

    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 vac...

  17. Accommodating and promoting multilingualism through blended learning

    OpenAIRE

    Olivier, Jak

    2011-01-01

    Multilingualism is a reality in South African classrooms. The Constitution of South Africa (Act 108 of 1996) and the national language policy recognize language rights and aims at supporting, promoting and developing the official languages. However, despite the advantages of mother tongue education, English is often chosen as language of learning and teaching at the cost of the African official languages. This study proposes the accommodation and promotion of multilingualism through blended l...

  18. DISCOURSE OF EDUCATION: ONLINE AND BLENDED LEARNING

    OpenAIRE

    PENKOV B.V.

    2015-01-01

    The study examines some features of educational discourse, including the concepts of online and blended learning within the context of high school. The object of research is high school, especially senior high school. The author looks into discourse markers for the use of concepts in the discourse of education. The features differentiate texts, which belong to the educational discourse and its genres as well as show the markers of contemporary discourse within the context. They study analyzes...

  19. Blended learning course to teach word processing

    OpenAIRE

    HAVELKA, Zbyněk

    2011-01-01

    This bachelor thesis deals with the problem of teaching computer science and various approaches to the teaching of the application environment. The work provides a comparison of available textbooks on the issue. Furthermore, in the theoretical part of the bachelor work is design a modern approach to teaching of the application environment. As a practical output of this work is, as its name suggests, the blended learning course to teach word processing, which is designed as a modern approach p...

  20. Facebook: A Versatile Platform for Blended Learning

    OpenAIRE

    Wong Ling Shing; Betty Voon Wan Niu

    2013-01-01

    Facebook is a popular networking tool among the young learners. This paper reports a practical usage of Facebook to engage learners in blended learning. The practical usage of Facebook in hosting online forums, sharing media files in vodcast, building collaborative content through Facebook Doc, and using Facebook as repository for articles and lecture notes has been described. Recent survey on 55 students revealed that a strong majority of the students agreed that Facebook has positive impact...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  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. 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 ...

  14. 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.

  15. 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.

  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

    Diacylglycerol (DAG) oils produced from sunflower oil and traditional sunflower oil were stored for 20 wk at 38 degrees C, and their oxidative stability was measured. Moreover, two butter blends were produced containing 40 wt-% DAG oil made from sunflower oil or rapeseed oil, respectively, as well...... as two control butter blends with sunflower oil or rapeseed oil. Their oxidative stability during storage at 5 degrees C for up to 12 wk was examined by similar means as for the pure oils. The storage study of the oils indicated that the DAG oil was oxidatively less stable as compared to sunflower oil......, but that they had similar sensory quality. Storage of the butter blends revealed that blends with the two types of rapeseed oil (triacylglycerol (TAG) or DAG oil) were oxidatively more stable than the blends containing oils from sunflower. There was no unambiguous indication of DAG butter blends having a different...

  17. 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.

  18. Structuring polymer blends with bicontinuous phase morphology. Part II. Tailoring blends with ultralow critical volume fraction

    DEFF Research Database (Denmark)

    Lyngaae-Jørgensen, Jørgen; Utracki, Leszek

    2003-01-01

    A hypothesis providing a guideline for the development of immiscible polymer blends with co-continuous phase structure at very low critical volume fraction of one component is. postulated and experimentally verified. Based on a number of simplifying assumptions the following relation was derived......: phi(cr) = k(lambdagamma)(1-z)/(theta(b)(*))(z) where lambdagamma is a Deborah number and theta(b)(*) is a dimensionless break-up time. The equation parameters, k and z are constant that depend on the flow field hence on the blending equipment. For the studies an internal mixer with Walzenkneter...

  19. 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.

  20. Performance of wet process method alternatives : terminal or continuous blend

    OpenAIRE

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Pais, Jorge C.; Trichês, Glicério

    2006-01-01

    This study presents the results of the research to investigate asphalt rubber mixtures produced with asphalt rubber binder obtained from two different processes; (i) terminal blend (produced in refinery); (ii) continuous blend (produced in laboratory). The experiment included the evaluation of fatigue and permanent deformation resistance of two gap graded mixtures (Caltrans ARHM -GG; ADOT AR-A C) and a dense gradation Asphalt Institute (AI) mix type IV) Two asphalt rubbers from terminal blend...

  1. Miscibility Phase Diagram of Ring Polymer Blends: A Topological Effect

    OpenAIRE

    Sakaue, Takahiro; Nakajima, Chihiro H.

    2016-01-01

    The miscibility of polymer blends, a classical problem in polymer science, may be altered, if one or both of the component do not have chain ends. Based on the idea of {\\it topological volume}, we propose a mean-field theory to clarify how the topological constraints in ring polymers affect the phase behavior of the blends. While the large enhancement of the miscibility is expected for ring-linear polymer blends, the opposite trend toward demixing, albeit comparatively weak, is predicted for ...

  2. Comparison of Hybrid Blends for Solar Cell Application

    OpenAIRE

    Maria C. Lechmann; Dominik Koll; Daniel Kessler; Patrick Theato; Wolfgang Tremel; Gutmann, Jochen S.

    2010-01-01

    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 2 rods. In this manner, we compare two different hole conducting polymers in t...

  3. Miscibility and Dynamic Mechanical Behavior of Blends with LCP'S

    OpenAIRE

    Gabellini, G.; Suman Bretas, R.

    1996-01-01

    The main advantage of the "in situ" production of blends of thermoplastics with liquid crystalline polymers (LCP's) is viscosity reduction. In this work the phase behavior of blends of poly p-phenylene sulphide (PPS) with two different LCP's is presented. The LCP's are HX1000 (amorphous) and HX4000, crystalline, both from DuPont. The samples were prepared by injection molding and its dynamic mechanical properties were tested after annealing. It was observed that before annealing the blends we...

  4. Enhancing the blended learning experience of Calculus I students

    OpenAIRE

    Al-Ghassani, A; H. Al Shamsi; Islam, M.; N. Al-Salti; I. Al-Hasni

    2015-01-01

    Blended Learning showed in the last two decades to be one of the effective ways in education and training. We illustrate our initiative experience with blended learning in the course Calculus I. The main goals we want to achieve are improving students understanding of the course concepts, increasing the level of uniformity in this multi-sections course and enhancing students blended learning experience online and offline. Consequently, this affects positively students' academic performance. W...

  5. Design and evaluation of two blended learning approaches: Lessons learned

    OpenAIRE

    Cheung, WS; Hew, KF

    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 face tutorials, classroom discussions, and a reflection session. For the second blended learning approach, we integrated two asynchronous tools with fa...

  6. Blended learning as an effective pedagogical paradigm for biomedical science

    OpenAIRE

    Hartfield, Perry

    2013-01-01

    Blended learning combines face-to-face class based and online teaching and learning delivery in order to increase flexibility in how, when, and where students study and learn. The development, integration, and promotion of blended learning in frameworks of curriculum design can optimize the opportunities afforded by information and communication technologies and, concomitantly, accommodate a broad range of student learning styles. This study critically reviews the potential benefits of blende...

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

    OpenAIRE

    Chun Meng Tang; Lee Yen Chaw

    2013-01-01

    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 o...

  8. COMBLE: European Community of Integrative Blended Learning Experts

    OpenAIRE

    Niemczik, Christian; Brenstein, Elke; Scholl, Margit

    2008-01-01

    The COMBLE project defines new and innovative models for the use of Blended learning in different educational backgrounds (vocational training, enterprises, universities, public bodies). To use the potentials of Blended learning a European wiki-based community called Methopedia will be established. By contributing to the development of Blended learning COMBLE supports ICT relevant methods that are indispensable for lifelong learning in Europe. Moreover, COMBLE will address to management-level...

  9. Blended learning in health education: three case studies

    OpenAIRE

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

  10. 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.

  11. 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.

  12. Blended working: for whom it may (not) work.

    Science.gov (United States)

    Van Yperen, Nico W; Rietzschel, Eric F; De Jonge, Kiki M M

    2014-01-01

    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. PMID:25033202

  13. 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.

  14. REVIEW: The Handbook Of Blended Learning: Global Perspectives, Local Designs

    OpenAIRE

    ATES, Reviewed By Alev

    2009-01-01

    Blended learning or blended e-learning sounds like a confusing term at first since it is relatively a new term for today’s instructors. However, Moore reports that it can be traced as far back as the 1920s which was called “supervised correspondence study”. For clarification of the term “blended learning” and informing the instructors about its common practices worldwide, the book provides readers a comprehensive resource about blended learning. It aims to raise awareness of adopting BL from ...

  15. 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.

  16. Self-Determined Blended Learning: A Case Study of Blended Learning Design

    Science.gov (United States)

    De George-Walker, Linda; Keeffe, Mary

    2010-01-01

    Higher education has been actively encouraged to find more effective and flexible delivery models to provide all students with access to quality learning experiences yet also meet institutional imperatives for efficiency and accountability. Blended learning, commonly defined as an integration of traditional face-to-face and online approaches to…

  17. 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…

  18. Line of sight stabilization - Sensor blending

    Science.gov (United States)

    Pettit, Christopher

    1991-10-01

    The paper examines a concept of blending inertial measuring sensors (IMS) which operate in different frequency ranges to produce an IMS sensor system that can measure base disturbances from dc to over 1000 Hz with minimum distortion. This information is them employed to point the line-of-sight (LOS) at a target with minimum jitter effects. Attention is given to a set of experimental results from this method involving the isolation of the LOS from the base motion of a space platform over a wide frequency range. The results reported, obtained from implementing the method on a two-body spacecraft simulator, include pointing stability and retargeting results. Results were encouraging.

  19. An Open Portal for Blended Learning

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Bouvin, Niels Olof; Petersen, Marianne Graves;

    2004-01-01

    The combination of traditional teaching and Web-based teaching, so called blended learning, is a challenge to the teachers as well as to the students. This shift in teaching demands an openness and flexibility from the technical platform which has not been found in the existing tools. Therefore....... This paper reflects on how the challenges with the creation of flexible Web-supported teaching are handled in two courses and how CourseWeb in the present and in the future is able to support this kind of teaching....

  20. Electrospun cellulose nitrate and polycaprolactone blended nanofibers

    Science.gov (United States)

    Nartker, Steven; Hassan, Mohamed; Stogsdill, Michael

    2015-03-01

    Pure cellulose nitrate (CN) and blends of CN and polycaprolactone were electrospun to form nonwoven mats. Polymers were dissolved in a mixed solvent system of tetrahydrofuran and N,N-dimethylformamide. The concentrations were varied to obtain sub-micron and nanoscale fiber mats. Fiber mats were analyzed using scanning electron microscopy, contact angle analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. The fiber morphology, surface chemistry and contact angle data show that these electrospun materials are suitable for applications including biosensing, biomedical and tissue engineering.

  1. 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

  2. Blended e-learning en universidades andaluzas

    OpenAIRE

    Tirado Morueta, Ramón; Pérez Rodríguez, María Amor; Aguaded Gómez, José Ignacio

    2011-01-01

    Conocer la implantación de la enseñanza virtual en el sistema universitario es hoy una prioridad básica en la investigación educativa para evaluar los nuevos procesos de enseñanza y aprendizaje que esta modalidad didáctica está generando. El ya llamado «blended e-learning» se ha ido implantando en las distintas universidades de todo el mundo con resultados muy variables. En este trabajo se presentan los resultados de un Proyecto de Investigación de Excelencia desarrollado en la...

  3. 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.

  4. 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.

  5. Blended learning specialists in radiation protection

    International Nuclear Information System (INIS)

    In this paper, we present a blended learning Radiation Protection Technician through an approved degree from the Polytechnic University of Valencia, which covers the knowledge and skills of functions relating to operators and supervisors in various areas and skilled workers to be to perform their work in technical units or Radiation Protection Radiation Protection Services. The benefits of this work are those related to achieving quality training flexible and adapted to follow the check off the person conducting the course, adapted to internal and external training of the applicant companies.

  6. 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

  7. 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.

  8. 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

  9. [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.

  10. 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 < 0.01) and a greater percentage of students agreed that 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 < 0.01). Blended exercise physiology laboratories provided an alternative method for delivering content that was favorably perceived by students and did not compromise student performance. PMID:26847259

  11. [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. PMID:24790050

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. A Blended Learning Approach to Course Design and Implementation

    Science.gov (United States)

    Hoic-Bozic, N.; Mornar, V.; Boticki, I.

    2009-01-01

    Blended learning has become an increasingly popular form of e-learning, and is particularly suitable to the process of transitioning towards e-learning from traditional forms of learning and teaching. This paper describes the use of the blended e-learning model, which is based on a mixture of collaborative learning, problem-based learning (PBL)…

  17. 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.

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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.…

  3. 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…

  4. 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…

  5. 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

  6. 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…

  7. 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…

  8. 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 ble...

  9. Access Patterns of Online Materials in a Blended Course

    Science.gov (United States)

    Asarta, Carlos J.; Schmidt, James R.

    2013-01-01

    Patterns in student accesses of online materials and their effects upon student performance in a blended course are examined. Our blended course is an introductory business and economic statistics course where lectures are only available online while the traditional class period is used for complementary learning activities. Timing, volumes,…

  10. Pareto optimality and robustness in bi-blending problems

    NARCIS (Netherlands)

    Herrera, J.F.; Casado, L.G.; Hendrix, E.M.T.; García, I.

    2014-01-01

    The mixture design problem for two products concerns finding simultaneously two recipes of a blending problem with linear, quadratic and semi-continuity constraints. A solution of the blending problem minimizes a linear cost objective and an integer valued objective that keeps track of the number of

  11. 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.

  12. 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

  13. Thermal and X-ray characterization of polymer blends

    NARCIS (Netherlands)

    Oudhuis, Alida Anna Catherina Maria; Pennings, A.J

    1995-01-01

    In the last decade many studies have focused on phase behaviour of polymer blends. It determines the morphology and therefore to a large extend the mechanical properties. The most simple, well known and often used property to determine phase behaviour in polymer blends is the glass transition temper

  14. 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

  15. Encouraging User Participation in Blended Learning: Course Reorientation

    Science.gov (United States)

    Fairchild, Alea M.

    2015-01-01

    Blended learning, structured as a combination of traditional course instruction and additional supporting multimedia course content, can be used in higher education for a variety of reasons. In the case study that we examine, the introduction of blended learning was initiated three years ago with the purpose of creating more resources for…

  16. Student Outcomes and Design Elements in Blended Learning Courses

    Science.gov (United States)

    Newbury, Robert

    2013-01-01

    The concept of "blended learning" appears with increasing frequency in academic literature, published research and general discussion as the latest trend in pedagogy. Known also as "hybrid education" and "web-enhanced instruction", blended learning courses have been reported as the method of delivery for 80 to 90…

  17. 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…

  18. 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...

  19. 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

  20. 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…

  1. Morphology and enzymatic degradation of thermoplastic starch-polycaprolactone blends

    NARCIS (Netherlands)

    Vikman, M.; Hulleman, S.H.D.; Zee, van der M.; Myllarinen, P.; Feil, H.

    1999-01-01

    This study's aim was to evaluate the effect of processing conditions on the morphology and enzymatic degradation of 50/50 (w/w) thermoplastic starch-polycaprolactone blends. The blends, produced from native potato starch, glycerol, and polycaprolactone in a melt mixer using different mixing speeds a

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

    OpenAIRE

    Norman Vaughan

    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 and external experts, leading to increased student success and satisfaction.

  3. 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... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.214 Spanish..., produced under this section, is designated “Spanish Type Blending Sherry.” Upon removal, the...

  4. 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. PMID:24507374

  5. Aging and mechanical properties of NR/BR blends

    Science.gov (United States)

    Chiu, Hsien-Tang; Tsai, Peir-An

    2006-02-01

    The mechanical properties and post-thermal aging properties of natural rubber (NR) and polybutadiene rubber (BR) blends at different blending ratios are investigated herein. The experimental results show that both tensile and tear strengths of NR/BR blends increase with increasing NR content. BR has a higher compression stiffness than NR. The deformation of BR is less than that of NR under the same load conditions. With regard to aging properties, both tensile stress and strain of NR/BR blends decrease after prolonged aging. In addition, the stress loss of BR is lower than that of NR, meaning that the aging resistance property of BR is superior to that of NR. Furthermore, accumulated thermal history has shifted the glass transition temperature (T g) of NR/BR blends toward lower temperatures while the loss tangent (tan δ) value increases with prolonged thermal aging.

  6. Mechanical and thermal properties of physically-blended-plastic films

    International Nuclear Information System (INIS)

    Low density polyethylene (LDPE) and isotactic polypropylene (PP) blend were produced in film form and were characterized by a number of techniques such as wide-angle x-ray diffraction (WAXD), differential thermal analysis (DTA), scanning electron microscopy (SEM), and instron tensile testing. Results of WAXD and DTA showed conclusively that the two components in the blend are incompatible. SEM micrographs indicated that the 60/40 and 40/60 PP/PE blends show approximately fine homogeneous dispersion of the minor component into the matrix of the major component. The mechanical properties of the blend films improved with respect to the PE homo polymer. The improvement was more remarkable with the increase of the PP component in the blend. Results obtained in this work were explained in terms of crystallinity and the crystallite orientation. 28 refs., 29 figs., 5 tabs. (A.M.H.)

  7. Morphology and Mechanical Properties of (Epoxy/PVC Blend

    Directory of Open Access Journals (Sweden)

    Awham M. Hameed

    2015-09-01

    Full Text Available In this research, the morphology and mechanical properties of (Epoxy/PVC blend were investigated. (EP/PVC blend was prepared by manual mixing of epoxy resin with different weight ratios of (Poly vinyl chloride (PVC after dissolving it in cyclohexanon. Five sheets of polymer blends in wt% included (0%, 5%, 10%, 15% and 20% of PVC were prepared at room temperature. Tests were carried out to study some mechanical properties for these blends and compared with the properties of pure epoxy. The morphology of the prepared materials was examined to study the compatibility nature between the two polymers under work. It was found that the best ratio of addition is (20% of PVC. This percentage gave the highest value of tensile strength compared with other percentages of mixing for (EP/PVC blends.

  8. Positron annihilation lifetime study of interfaces in ternary polymer blends

    Science.gov (United States)

    Meghala, D.; Ramya, P.; Pasang, T.; Raj, J. M.; Ranganathaiah, C.; Williams, J. F.

    2013-06-01

    A new method based on positron lifetime spectroscopy is developed to characterize individual interfaces in ternary polymer blends and hence determine the composition dependent miscibility level. The method owes its origin to the Kirkwood-Risemann-Zimm (KRZ) model for the evaluation of the hydrodynamic interaction parameters (αij) which was used successfully for a binary blend with a single interface. The model was revised for the present work for ternary polymer blends to account for three interfaces. The efficacy of this method is shown for two ternary blends namely poly(styrene-co-acrylonitrile)/poly (ethylene-co-vinylacetate)/poly(vinyl chloride) (SAN/EVA/PVC) and polycaprolactone /poly(styrene-co-acrylonitrile)/poly(vinyl chloride) (PCL/SAN/PVC) at different compositions. An effective hydrodynamic interaction parameter, αeff, was introduced to predict the overall miscibility of ternary blends.

  9. A blend of Sodium Humate/SLES/Herbal Oils

    Directory of Open Access Journals (Sweden)

    Yeliz Akyiğit

    2013-08-01

    Full Text Available A blend of sodium humate (SH with anionic surfactants such as sodium lauryl ether sulfate (SLES was prepared by solution mixing at medium of herbal oils at 25, 50 and 75°C. Its miscibility studies were carried out by using physical techniques over an extended range of concentration and composition in buffer solution. In addition, to ascertain the state of miscibility of the blends, they were investigated by using UV-visible spectrophotometer and Fourier transform infrared (FTIR. These values revealed that the blend is miscible when the sodium humate content is more than %60 in the blend at all temperatures. There were no important differences in the characteristics of the blends at different temperatures.It was thought that the mechanism ofthe complex formation is realized by making strong intermolecular interaction like hydrogen bonds between the carbonyl groups in humic acid and hydroxyl groups in fatty acids.

  10. 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.

  11. 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.

  12. Extending the Semiotics of Embodied Interaction to Blended Spaces

    Directory of Open Access Journals (Sweden)

    Shaleph J. O'Neill

    2015-01-01

    Full Text Available In this paper, we develop a new way of understanding interactions in blended spaces. We do this by developing ideas about embodied semiotics and then apply these ideas to the analysis of interaction in mixed-reality blended spaces (where the physical world and digital world are blended deliberately to provide new forms of interaction. We discuss how blended spaces provide a new medium within which people have experiences. The semiotic analysis reveals how blended spaces are constructed across the physical and the digital, highlighting the ontology, topology, volatility, and agency present within them. It shows how people move between the physical and digital spaces through the objects and places that anchor them together. Our approach reveals more about the way bodily and higher cognitive functions are brought into play within a holistic interactive experience in which people move physically and conceptually through the layers of experience that make up the interaction.

  13. A novel blending method for dispensing powdered medicine.

    Science.gov (United States)

    Miyazaki, Yasunori; Miyawaki, Kaoru; Uchino, Tomonobu; Kagawa, Yoshiyuki

    2014-01-01

    We introduced the application of a planetary centrifugal mixer to dispensing powdered medicines to prevent from individual variation in the skills of pharmacists with a manual blending. The blending performance of the mixer was explored in terms of four operational variables, namely, operation speed (400-1000 rpm), operation time (10-60 s), charging rate in vessel (20-50%), and size of vessel (35, 58, 125, 550 mL), using colored lactose and crystalline lactose as the principle model medicine and diluent, respectively. The blending degree was assessed by image analysis, so the extent of uniformity was expressed as the relative standard deviation of the color difference signal Cb value of YCrCb color space. Application of the mixer to blending three commercial medicines with diluents was carried out. Sufficient blending was achieved at 10 s using a 20% charging rate and 35 mL vessel irrespective of operation speed. As the charging rate was increased, a higher operation speed was needed to obtain uniform blending. A larger sized vessel also required a higher operation speed. Uniform blending was achieved in all of the mixtures of colored lactose and crystalline lactose at the weight ratio of 1 : 9-9 : 1. In the application studies using Adona®, Anginal® and Neophylline® powder, the blending performance of the mixer was equivalent to that of the manual blending method, showing relative standard deviations of 2.2-3.3% and 1.8-3.8%, respectively. These results revealed that the planetary centrifugal mixer was suitable for blending powdered medicine. PMID:24390492

  14. 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…

  15. 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…

  16. Rheology of miscible polymer blends with hydrogen bonding

    Science.gov (United States)

    Yang, Zhiyi

    Poly(4-vinylphenol) (PVPh) was blended with four different polymers: poly(vinyl methyl ether) (PVME), poly(vinyl acetate) (PVAc), poly(2-vinylpyridine) (P2VP), and poly(4-vinylpyridine) (P4VP) by solvent casting. The miscibility of these four PVPh-based blend systems was investigated using differential scanning calorimetry (DSC) and the composition-dependent glass transition temperature (Tg) was predicted by a thermodynamic theory. The hydrogen bonds between phenolic group in PVPh and ether group, carbonyl group or pyridine group was confirmed by Fourier transform infrared (FTIR) spectroscopy. The fraction of hydrogen bonds was calculated by the Coleman-Graf-Painter association model. Linear dynamic viscoelasticity of four PVPh-based miscible polymer blends with hydrogen bonding was investigated. Emphasis was placed on investigating how the linear dynamic viscoelasticity of miscible polymer blends with specific interaction might be different from that of miscible polymer blends without specific interaction. We have found that an application of time-temperature superposition (TTS) to the PVPh-based miscible blends with intermolecular hydrogen bonding is warranted even when the difference in the component glass transition temperatures is as large as about 200°C, while TTS fails for miscible polymer blends without specific interactions. On the basis of such an observation, we have concluded that hydrogen bonding suppressed concentration fluctuations in PVPh-based miscible blends. It has been found that both the intra-association (self-association) of the phenoxy hydroxyl groups in PVPh and inter-association (intermolecular interactions) between the constituent components have a profound influence on the frequency dependence of dynamic moduli in the terminal region of the PVPh-based miscible blend systems investigated. Hydrogenated functional polynorbornenes (HFPNBs) were synthesized and they were used to investigate the miscibility and rheology of HFPNB

  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. 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.

  19. Blending in Nuclear Waste Tanks (Salt Disposition Initiative/Tank 50: Blending and Sludge Disturbance Study)

    International Nuclear Information System (INIS)

    The conclusions of this presentation are: (1) Designed, built, and fabricated the test equipment in 16 work days - (a) Six weeks to completion of initial 38 tests, (b) Total of 120 pilot scale tests, 30 CFD models, and 240 material property tests are complete, or in process. (2) 95% blending can be achieved in less than 12 hours - (a) Estimate from in-process test results, (b) Blending time at full scale will be checked from calculations in process, (c) Three to four days typically required to blend tank contents; (3) Recommendation to use one, non-rotating, pump instead of two for each of three tanks. (Pump cost per tank > 1 million dollars) - (a) Pump design parameters provided to SRR: nozzle velocity, nozzle diameter, nozzle angle from horizontal, and pump orientation with respect to the tank wall; and (4) Sludge disturbance was controlled at pilot scale - (a) Numerous models investigated, (b) Sludge disturbance at full scale will be established using CFD modeling and pilot scale test results.

  20. Blending biodiesel in fishing boat fuels for improved fuel characteristics

    Directory of Open Access Journals (Sweden)

    Cherng-Yuan eLin

    2014-02-01

    Full Text Available Biodiesel is a renewable, clean, alternative energy source with advantages such as excellent lubricity, superior biodegradability and high combustion efficiency. Biodiesel is considered for mixing with fishing boat fuels to adjust their fuel characteristics so that toxic pollutants and greenhouse-effect gas emissions from such shipping might be reduced. The effects of blending fishing boat fuels A and B with various weight proportions of biodiesel are experimentally investigated in this study. The results show that biodiesel blending can significantly improve the inferior fuel properties of both fishing boat fuels and particularly fuel B. The flash points of both of these fuels increases significantly with the addition of biodiesel and thus enhances the safety of transporting and storing these blended fuels. The flash point of fishing boat fuel B even increases by 16% with 25 wt% biodiesel blending. The blending of biodiesel with no sulfur content is found to be one of the most effective ways to reduce the high sulfur content of fishing boat fuel, resulting in a reduction in the emission of sulfur oxides. The addition of only 25 wt% biodiesel decreased the sulfur content of the fishing boat fuel by 37%. The high kinematic viscosity of fishing boat fuel B was also observed to be reduced by 63% with the blending of just 25 wt% biodiesel. However, biodiesel blending caused a slight decrease in heating value around 1% to 4.5%.

  1. Production of silk sericin/silk fibroin blend nanofibers

    Directory of Open Access Journals (Sweden)

    Zhang Xianhua

    2011-01-01

    Full Text Available Abstract Silk sericin (SS/silk fibroin (SF blend nanofibers have been produced by electrospinning in a binary SS/SF trifluoroacetic acid (TFA solution system, which was prepared by mixing 20 wt.% SS TFA solution and 10 wt.% SF TFA solution to give different compositions. The diameters of the SS/SF nanofibers ranged from 33 to 837 nm, and they showed a round cross section. The surface of the SS/SF nanofibers was smooth, and the fibers possessed a bead-free structure. The average diameters of the SS/SF (75/25, 50/50, and 25/75 blend nanofibers were much thicker than that of SS and SF nanofibers. The SS/SF (100/0, 75/25, and 50/50 blend nanofibers were easily dissolved in water, while the SS/SF (25/75 and 0/100 blend nanofibers could not be completely dissolved in water. The SS/SF blend nanofibers could not be completely dissolved in methanol. The SS/SF blend nanofibers were characterized by Fourier transform infrared (FTIR spectroscopy, differential scanning calorimetry, and differential thermal analysis. FTIR showed that the SS/SF blend nanofibers possessed a random coil conformation and ß-sheet structure.

  2. Production of silk sericin/silk fibroin blend nanofibers

    Science.gov (United States)

    Zhang, Xianhua; Tsukada, Masuhiro; Morikawa, Hideaki; Aojima, Kazuki; Zhang, Guangyu; Miura, Mikihiko

    2011-08-01

    Silk sericin (SS)/silk fibroin (SF) blend nanofibers have been produced by electrospinning in a binary SS/SF trifluoroacetic acid (TFA) solution system, which was prepared by mixing 20 wt.% SS TFA solution and 10 wt.% SF TFA solution to give different compositions. The diameters of the SS/SF nanofibers ranged from 33 to 837 nm, and they showed a round cross section. The surface of the SS/SF nanofibers was smooth, and the fibers possessed a bead-free structure. The average diameters of the SS/SF (75/25, 50/50, and 25/75) blend nanofibers were much thicker than that of SS and SF nanofibers. The SS/SF (100/0, 75/25, and 50/50) blend nanofibers were easily dissolved in water, while the SS/SF (25/75 and 0/100) blend nanofibers could not be completely dissolved in water. The SS/SF blend nanofibers could not be completely dissolved in methanol. The SS/SF blend nanofibers were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and differential thermal analysis. FTIR showed that the SS/SF blend nanofibers possessed a random coil conformation and ß-sheet structure.

  3. A Study on Students’ Views On Blended Learning Environment

    Directory of Open Access Journals (Sweden)

    Meryem YILMAZ SOYLU

    2006-07-01

    Full Text Available In the 21st century, information and communication technologies (ICT have developed rapidly and influenced most of the fields and education as well. Then, ICT have offered a favorable environment for the development and use of various methods and tools. With the developments in technology, blended learning has gained considerable popularity in recent years. Together with the developments it brought along the description of particular forms of teaching with technology. Blended learning is defined simply as a learning environment that combines technology with face-to-face learning. In other words blended learning means using a variety of delivery methods to best meet the course objectives by combining face-to-face teaching in a traditional classroom with teaching online. This article examines students’ views on blended learning environment. The study was conducted on 64 students from Department of Computer Education and Instructional Technologies in 2005–2006 fall semester in Instructional Design and Authoring Languages in PC Environment at Hacettepe University. The results showed that the students enjoyed taking part in the blended learning environment. Students’ achievement levels and their frequency of participation to forum affected their views about blended learning environment. Face-to-face interaction in blended learning application had the highest score. This result demonstrated the importance of interaction and communication for the success of on-line learning.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Imaging blended VSP data using full wavefield migration

    OpenAIRE

    Soni, A.K.; Verschuur, D.J.

    2013-01-01

    Blended source and/or simultaneous source acquisition for multi-offset and multi-azimuth VSP measurements can prove significantly beneficial in saving expensive borehole down-time. In the last few years, for the case of surface seismic data, it was proposed to redefine imaging and inversion of the blended data to handle the data directly without any need to separate the blended sources. Recently, we proposed the concept of full wavefield migration (FWM) to image VSP data, where using all the ...

  13. 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.

  14. Isothermal Melt Crystallization Kinetics of PP/organoclay Blends

    Directory of Open Access Journals (Sweden)

    Wang Kunyan

    2016-01-01

    Full Text Available Polystyrene (PP/organoclay (OMMT blends were prepared by co-rotating twin-screw extruder. The effects of OMMT on isothermal crystallization behaviors of blends was studied by differential scanning calorimetry (DSC. Using Avrami equation analysis the crystallization kinetics of materials. The analysis result shows that the OMMT act as effective nucleating agents, accelerating the crystallization of PP, then lead the rate of crystallization increased. Avrami exponent n is between 2.04~3.57, which indicating that PP/OMMT blends crystallization process might correspond to a two-dimensional or three-dimensional growth process. The activation enerigies for isotheraml crystallization were determined by the Arrhenius equation.

  15. Pivalolactone, 3. Reactive blending of polypivalolactone with polycarbonate

    OpenAIRE

    Tijsma, Edze Jan; Does, van der, A.J.W.; Bantjes, Adriaan; Vulic, Ivan; Werumeus Buning, Gerard Hidde

    1994-01-01

    The occurrence of interchange reactions during heating of polypivalolactone (PPVL) with three polymers and their influence on the blend properties were studied. Physical blends of PPVL and bisphenol-A polycarbonate (PC) were found to be immiscible. By heating of PPVL/PC blends in the melt at 280°C, in diphenyl ether at 260°C and in a twin-screw extruder (TSE) at 280°C partial formation of copolymers was observed, provided that tetrabutyl orthotitanate (TnBT) was added. After heating of equimo...

  16. Viscometric and Rheological Behaviour of Chitosan-Hydrophilic Polymer Blends

    OpenAIRE

    R. K. Wanchoo; Thakur, Anupama; Sweta, A.

    2008-01-01

    Blends of chitosan with hydrophilic polymers were investigated for miscibility. Chitosan/poly (vinyl alcohol) (CS/PVA), chitosan/poly vinylpyrollidone (CS/PVP) and chitosan/poly (ethylene oxide) (CS/PEO) blends were prepared in dilute aqueous acetic acid ( = 1 %) and found to be miscible over the entire composition range by dilute solution viscosity and rheological measurements. The miscibility of blends by viscosity measurements at 25 ± 0.1 C was estimated on the basis of experimental and ...

  17. 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.

  18. 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.

  19. 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

  20. TRANSESTERIFICATION IN POLYPHENYLSILSISQUIOXANE (PPSQ)/POLY ETHYLENE TEREPHTHALATE (PET) BLENDS

    Institute of Scientific and Technical Information of China (English)

    LI Guizhi; SHI Lianghe; YE Meiling; ZHAO Chuntian; XU Mao

    1995-01-01

    The chemical structure of copolymer formed in the transesterification of PPSQ/PET blends during melt-processing is deduced from the 1H-NMR spectra. The transesterification extent of this blend is interpreted by the changes of crystalline melting peak in DSC thermograms of the insoluble products containing unreacted PET and some block PPSQ segments. Effects of composition of blend ladderlike regularity of PPSQ on the reaction extent have also been discussed.Inclusion of some block PPSQ segments in PET has no influence on the crystalline morphology of PET.

  1. Phosphor blends for high-CRI fluorescent lamps

    Science.gov (United States)

    Setlur, Anant Achyut; Srivastava, Alok Mani; Comanzo, Holly Ann; Manivannan, Venkatesan; Beers, William Winder; Toth, Katalin; Balazs, Laszlo D.

    2008-06-24

    A phosphor blend comprises at least two phosphors each selected from one of the groups of phosphors that absorb UV electromagnetic radiation and emit in a region of visible light. The phosphor blend can be applied to a discharge gas radiation source to produce light sources having high color rendering index. A phosphor blend is advantageously includes the phosphor (Tb,Y,LuLa,Gd).sub.x(Al,Ga).sub.yO.sub.12:Ce.sup.3+, wherein x is in the range from about 2.8 to and including 3 and y is in the range from about 4 to and including 5.

  2. Design of Sustainable Blended Products using an Integrated Methodology

    DEFF Research Database (Denmark)

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

    2013-01-01

    to be used as building blocks in the mixture design, and then to propose the blend formulations that fulfill the desired product attributes. The result is a set of blends that match the constraints, the compositions, values of the target properties and information about their miscibility. The methodology has......This paper presents a systematic methodology for designing blended products consisting of three stages; product design, process identification and experimental verification. The product design stage is considered in this paper. The objective of this stage is to screen and select suitable chemicals...

  3. 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.

  4. 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.

  5. 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...

  6. 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: the pro...... methodology is highlighted through two case studies involving gasoline blends and lubricant base oils....

  7. 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.

  8. 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.

  9. Modeling terminal ballistics using blending-type spline surfaces

    Science.gov (United States)

    Pedersen, Aleksander; Bratlie, Jostein; Dalmo, Rune

    2014-12-01

    We explore using GERBS, a blending-type spline construction, to represent deform able thin-plates and model terminal ballistics. Strategies to construct geometry for different scenarios of terminal ballistics are proposed.

  10. 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.

  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. 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

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

    DEFF Research Database (Denmark)

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

    Topic: 02 Scholarship of teaching and learning Abstract id: 140608-E-1270 Title: PERCEPTION OF BLENDED LEARNING INVENTORY (POBLI) – DEVELOPMENT AND VALIDATION Berit Lassesen 1,*Dorte S. Rossen 1Maria Hvid Stenalt 1,* Aarhus University, Aarhus, Denmark Background: Aarhus University (DK) has chosen...... a new strategic focus on 'Educational IT’ with the purpose of strengthening teaching and learning through use of online interactions. Some of the major challenges in the development of this strategy include how to, identify rationales for using blended learning, stimulate pedagogical reflections...... 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...

  14. 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.

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

    Science.gov (United States)

    Gil, M V; Oulego, P; Casal, M D; Pevida, C; Pis, J J; Rubiera, F

    2010-11-01

    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 (raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends. PMID:20605093

  16. Chemical interesterification of blends with palm stearin and patawa oil.

    Science.gov (United States)

    Oliveira, Pedro D; Rodrigues, Antonio M C; Bezerra, Carolina V; Silva, Luiza H M

    2017-01-15

    The present study sought to develop lipid bases from blends between patawa oil and palm stearin. These blends were analyzed before and after the chemical interesterification process for their fatty acid and triacylglycerol composition, free fatty acid (FFA) content, peroxide index, thermal properties, melting point, consistency, and solid fat content (SFC). Blends with unsaturated fatty acid contents between 60 and 70% were obtained, with a good ratio between saturated and unsaturated fatty acids, which indicates a healthy content of fatty acids. Variations in the triacylglycerol contents and melting and crystallization thermograms evidenced the reaction. The blend with 50% stearin and 50% patawa oil showed the best results after the chemical interesterification reaction regarding the possible application in fatty products for its appropriate melting point, SFC similar to that of soft table margarines, plastic and spreadable consistency at refrigeration temperature, thus combining physical and nutritional properties desirable for the food industry. PMID:27542488

  17. Enhancing the blended learning experience of Calculus I students

    Directory of Open Access Journals (Sweden)

    A. Al-Ghassani

    2015-08-01

    Full Text Available Blended Learning showed in the last two decades to be one of the effective ways in education and training. We illustrate our initiative experience with blended learning in the course Calculus I. The main goals we want to achieve are improving students understanding of the course concepts, increasing the level of uniformity in this multi-sections course and enhancing students blended learning experience online and offline. Consequently, this affects positively students' academic performance. We describe and discuss the results that we achieved and the challenges we encountered in view of the initiative aims and goals. The blended learning delivery methods were through Learning Management System (LMS as the online medium and through new offline activities inside and outside the classroom. The LMS we used is Moodle. We designed the resources and activities to cater for the learners different needs. The offline activities were chosen and designed to strengthen the weakness in students study skills based in our experience.

  18. 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.

  19. A Study on Students’ Views On Blended Learning Environment

    OpenAIRE

    Meryem YILMAZ SOYLU; AKKOYUNLU, BUKET

    2006-01-01

    In the 21st century, information and communication technologies (ICT) have developed rapidly and influenced most of the fields and education as well. Then, ICT have offered a favorable environment for the development and use of various methods and tools. With the developments in technology, blended learning has gained considerable popularity in recent years. Together with the developments it brought along the description of particular forms of teaching with technology. Blended learning is def...

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

    OpenAIRE

    Hasmukh S. Patel; Panchal, Kumar K.

    2004-01-01

    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 ...

  1. General Blending Models for Mixture Experiments: Design and Analysis

    OpenAIRE

    Brown, Liam John

    2014-01-01

    It is felt the position of the Scheffé polynomials as the primary, or sometimes sole recourse for practitioners of mixture experiments leads to a lack of enquiry regarding the type of blending behaviour that is used to describe the response and that this could be detrimental to achieving experimental objectives. Consequently, a new class of models and new experimental designs are proposed allowing a more thorough exploration of the experimental region with respect to different blending behavi...

  2. 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 ...

  3. Photophysical studies of poly-isocyanopeptide based photovoltaic blends

    OpenAIRE

    Finlayson, C E; Whitney, A D

    2010-01-01

    Abstract We report a photophysical study of photovoltaic blends containing perylene-substituted polyisocyanide (pery-PIC) materials, using time-correlated single photon counting (TCSPC) and photo-induced absorption spectroscopy, and compare the key characteristics to analogous perylene-diimide (PDI) monomer blends with polythiophene- and polyfluorene-based conjugated polymers. Pery-PIC consists of semiconducting perylene units, which self-stack in a regular fashion around a rigid helical p...

  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. 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.

  6. Preparation and characterization of thermoplastic starch/zein blends

    OpenAIRE

    Elisângela Corradini; Antonio José Felix de Carvalho; Antonio Aprigio da Silva Curvelo; José Augusto Marcondes Agnelli; Luiz Henrique Capparelli Mattoso

    2007-01-01

    Blends of starch and zein plasticized with glycerol were prepared by melting processing in an intensive batch mixer connected to a torque rheometer at 160 °C. The resulting mixtures were compression molded and then characterized by scanning electron microscopy, differential scanning calorimetry, wide-angle X ray diffraction and water-absorption experiments. The blends were immiscible, showing two distinct phases of starch and zein. The water uptake at equilibrium and its diffusion coeffic...

  7. Investigation into the Possibilities of Using Fuel Blends in Locomotives

    Directory of Open Access Journals (Sweden)

    Dmitrij Kolesnikov

    2012-11-01

    Full Text Available The paper examines the structural features and properties of fuel blends and fuel emulsions, presents an overview of formulas obtained getting stable emulsions and analyses the results of experimental studies on preparing mixtures made of different quantities of diesel and various additives considering certain parameters. The article discusses the dependence of the size of resulting particles of water in the emulsion and describes an impact of various additives on the size of particles and time for blend delamination.

  8. Teacher Adoption of Web-based Learning in Blended Environment

    OpenAIRE

    Fung, HNH; Yuen, AHK

    2006-01-01

    Because of the significant benefits to be gained from Internet technology, many educational institutions have brought in online learning management systems to their traditional classroom courses. The emergence of blended instruction allows teachers to integrate the advantages of face-to-face classroom interactions with positive attributes of distance learning. Nevertheless, the value of the blended approach relies heavily on the teachers’ adoption of the add-on platform. In view of the fact t...

  9. THE SUCCESSFUL INCORPORATION OF BLENDED LEARNING INTO THE LANGUAGE CURRICULUM

    OpenAIRE

    Simpson, Adam J.

    2016-01-01

    A phenomenon attracting increasing attention in language curricula is the infusion of technology into traditional, face-to-face (FTF) language instruction. Nevertheless, computer-assisted language learning (CALL) still lacks a body of qualitative research on the notion of blended learning (BL). Particularly, what is lacking is information regarding teachers' perceptions of blended learning, or the roles they are expected to play in such mixed environments; without an understanding of these is...

  10. The characterization of novel biodegradable blends based on polyhydroxybutyrate

    OpenAIRE

    Pankova, Yulia; Shchegolikhin, Alexandr; lordanskii, Alexey; Zhulkina, Anna; Ol'khov, Anatoliy; Zaikov, Gennady

    2011-01-01

    The present paper focuses on the study of novel blends based on poly(3-hydroxybutyrate) (PHB) and polymers with different hydrophilicity (LDPE and PA). Polymer blends were produced from five ratios of PHB/LDPE in order to regulate the resistance to hydrolysis or (bio)degradation through the control of water permeability. The relation between the water transport and morphology (TEM data) shows the impact of polymer component ratio on the regulating water flux in a hydrophobic matrix. To elucid...

  11. Chemical and Enzymatic Hydrolysis of Polyurethane/Polylactide Blends

    OpenAIRE

    Joanna Brzeska; Aleksandra Heimowska; Wanda Sikorska; Lidia Jasińska-Walc; Marek Kowalczuk; Maria Rutkowska

    2015-01-01

    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 ...

  12. Preparation and characterization of Polyhydroxyalkanoates (PHA) and Polylactide (PLA) blends

    OpenAIRE

    Gérard, Thibaut; Budtova, Tatiana

    2011-01-01

    International audience Polylactide (PLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) blends were prepared in different compositions by melt mixing. The miscibility of the two components was first characterized by differential scanning calorimetry (DSC) experiments, which showed the immiscibility of the components for all blend compositions. The morphology was studied using scanning electron microscope (SEM) and optical microscopy in reflection. Nodular and co-continuous morphologie...

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

    OpenAIRE

    Gabriella Dodero; Rosella Gennari

    2015-01-01

    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.

  14. A blended learning concept for guided self-instruction

    OpenAIRE

    Schreurs, Jeanne; Al-Zoubi, A.Y.

    2007-01-01

    Learning models are evolving from instructor centred, over learner centred to learning team-centred approach. learning is evolving to guide individual and collaborative self-paced web-based learning. In this paper, a supervised and guided individual self-paced web-based learning concept including collaborative learning in a virtual class is adapted. Blended learning is set forward as the solution. We focus on the requirements of the blended learning concept to be a good solution for this lear...

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

    OpenAIRE

    Chew, Charles; Wee, Loo Kang

    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 appr...

  16. 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.

  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. Implementing Blended Learning Technology in Higher Professional Education

    OpenAIRE

    Matukhin, Dmitriy Leonidovich; Zhitkova, Elena

    2015-01-01

    The paper dwells on the learning outcomes of experimental implementing of blended learning technology in the English language teaching to engineering students of the Tomsk Polytechnic University. The aim of blended learning application is to enhance efficiency of the learning process by means of up-to-date highly-technological means of instruction. The author identified the level of information competency of engineering students, analyzed psychological readiness of engineering students to han...

  19. Study of Blended Learning Process in Education Context

    OpenAIRE

    Asif Irshad Khan; Noor-ul-Qayyum; Mahaboob Sharief Shaik; Abdullah Maresh Ali; Ch.Vijaya Bebi

    2012-01-01

    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 b...

  20. A Blended Learning Model For Teaching Practice Course

    OpenAIRE

    Mustafa CANER

    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 growth of pre-service teachers. Since it will increase the contact hours among students and university supervisors and facilitate peer feedback amon...

  1. Assessing the impact of blended learning on student performance

    OpenAIRE

    Do Won Kwak; Flavio Menezes; Carl Sherwood

    2013-01-01

    This paper assesses quantitatively the impact on student performance of a blended learning experiment within a large undergraduate first year course in statistics for business and economics students. We employ a differences- in-difference econometric approach, which controls for differences in student characteristics and course delivery method, to evaluate the impact of blended learning on student performance. Although students in the course manifest a preference for live lectures over online...

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

    OpenAIRE

    ATES, Reviewed By Alev

    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...

  3. 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.

  4. Enzymatic removal of cellulose from cotton/polyester fabric blends

    OpenAIRE

    Vasconcelos, Andreia; Paulo, Artur Cavaco

    2006-01-01

    The production of light-weight polyester fabrics from a polyester/cotton blended fabric, by means of the enzymatic removal of the cellulosic part of the material, was investigated. The removal of cotton from the blended fabric yielded more than 80% of insoluble microfibrillar material by the combined action of high beating effects and cellulase hydrolysis.Other major features of this enzymatic process for converting cotton fibers into microfibrillar material are bath ratio, enzyme dosage a...

  5. Study of the Blending Efficiency of Pitched Blade Impellers

    OpenAIRE

    I. Fořt; T. Jirout; Rieger, F.; Allner, R.; R. Sperling

    2001-01-01

    This paper presents an analysis of the blending efficiency of pitched blade impellers under a turbulent regime of flow of an agitated low viscous liquid. The conductivity method is used to determine of the blending (homogenization) time of miscible liquids in pilot plant mixing equipment with standard radial baffles. For the given homogeneity degree (98 %) a three-blade pitched blade impeller is tested with various off-bottom clearances, vessel/ impeller diameter ratios and various impeller p...

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. TIME-TEMPERATURE-MISCIBILITY AND MORPHOLOGY OF POLYOLEFIN BLENDS

    Institute of Scientific and Technical Information of China (English)

    Robert A.Shanks; Jun Li; Fei Chen; Gandara Amarasinghe

    2000-01-01

    Miscibility and crystallization have been studied for polypropylene-polyethylene and polyethylene-polyethylene blends. In the case of the polypropylene blends the composition of interest is 20% polypropylene. At this composition the polypropylene has been found to be soluble in linear low density polyethylene but insoluble in high, low and very low density polyethylenes. The miscibility has been concluded from the crystallization kinetics and polarised optical microscopy with a hot stage. Polyethylene-polyethylene blends have been formed from polymers with similar average branching content but where they have different melting temperatures. Important consequences are to introduce long branches into a polyethylene that only has short branches, and to modify the morphology of a polyethylenes so that haze, gloss and strain hardening are improved. Polyethylene blends must be developed after careful consideration of the branch content and distribution within each of the constituents. It is not sufficient to simply blend polyethylenes, with the desired range of properties, without regard to the miscibility of the blend composition.

  12. Morphological studies on block copolymer modified PA 6 blends

    Energy Technology Data Exchange (ETDEWEB)

    Poindl, M., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de [Institut für Kunststofftechnik, University of Stuttgart (Germany)

    2014-05-15

    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. 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.

  14. GAS PERMEATION OF SEGMENTED POLYURETHANES AND THEIR BLENDS WITH PVC

    Institute of Scientific and Technical Information of China (English)

    TIAN Minmin; ZHANG Xian; LIU Shangqi; XIAO Fengfei; HU Shiru; XU Mao

    1989-01-01

    Film specimens of four segmented polyurethanes with different soft segments, namely polycaprolactone,polytetramethylene adipate,polytetramethylene oxide and polypropylene oxide,and their blends with PVC of different compositions were obtained by solution cast. The permeability of these films to O2,N2 and H2 and their density were measured by using gas chromatography and technique of density gradient column. The polyether polyurethanes were found to have higher permeability than the polyester ones due to their low glass transition temperature and /6r the low density value.The blends of PVC and polyether polyurethanes, especially the PPO-based polyurethane, are incompatible, and their permeability coefficient-composition dependence has the typical S-shaped curves. PVC is well compatible with the soft segments in its blends with polyester polyurethanes. For these blends the composition dependence of permeability is characterized by a negative deviation from the semilogarithmic additivity rule,and it is possible to prepare blends having Tg 20 ℃ lower than that of PVC, but retaining its low permeability almost unchanged. results were discussed in according with the different approaches for the permeation behavior of compatible and incompatible blends.

  15. 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.

  16. Blends of Poly (lactic acid) with Thermoplastic Acetylated Starch

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kun-yu; RAN Xiang-hai; ZHUANG Yu-gang; YAO Bin; DONG Li-song

    2009-01-01

    Blends of poly(lactic acid)(PLA) and thermoplastic acetylated starch(ATPS) were prepared by means of the melt mixing method. The results show that PLA and ATPS were partially miscible, which was confirmed with the measurement of T_g by dynamic mechanical analysis(DMA) and differrential scanning calorimetry(DSC). The mechanical and thermal properties of the blends were improved. With increasing the ATPS content, the elongation at break and impact strength were increased. The elongation at break increased from 5% of neat PLA to 25% of the blend PLA/ATPS40. It was found that the cold crystallization behavior of PLA changed evidently by addition of ATPS. The cold crystallization temperature(T_(cc)) of each of PLA/ATPS blends was found to shift to a lower temperature and the width of exothermic peak became narrow compared with that of neat PLA. The thermogravimetry analy-sis(TGA) results showed that the peak of derivative weight for ATPS moved to higher temperature with increasing PLA content in PLA/ATPS blends. It can be concluded that PLA could increase the thermal stability of ATPS. The rheological measurement reveals the melt elasticity and viscosity of the blends decreased with the increased concentration of ATPS, which was favorable to the processing properties of PLA.

  17. Non-isothermal crystallization of PET/PLA blends

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huipeng [Department of Physics and Astronomy, Tufts University, 4 Colby Street, Medford, MA 02155 (United States); Pyda, Marek [Department of Chemistry, The University of Technology, Rzeszow, 35959 Rzeszow (Poland); Cebe, Peggy, E-mail: peggy.cebe@tufts.edu [Department of Physics and Astronomy, Tufts University, 4 Colby Street, Medford, MA 02155 (United States)

    2009-08-10

    Binary blends of poly(ethylene terephthalate) with poly(lactic acid), PET/PLA, were studied by differential scanning calorimetry and X-ray scattering. The PET/PLA blends, prepared by solution casting, were found to be miscible in the melt over the entire composition range. Both quenched amorphous and semicrystalline blends exhibit a single, composition dependent glass transition temperature. We report the non-isothermal crystallization of (a) PET, with and without the presence of PLA crystals and (b) PLA, with and without the presence of PET crystals. PET can crystallize in all blends, regardless of whether PLA is amorphous or crystalline, and degree of crystallinity of PET decreases as PLA content increases. In contrast, PLA crystallization is strongly affected by the mobility of the PET fraction. When PET is wholly amorphous, PLA can crystallize even in 70/30 blends, albeit weakly. But when PET is crystalline, PLA cannot crystallize when its own content drops below 0.90. These different behaviors may possibly be related to the tendency of each polymer to form constrained chains, i.e., to form the rigid amorphous fraction, or RAF. PET is capable of forming a large amount of RAF, whereas relatively smaller amount of RAF forms in PLA. Like the crystals, the rigid amorphous fraction of one polymer component may inhibit the growth of crystals of the other blend partner.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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. PMID:26686863

  5. On unfamiliar Italian lexical blends from names and nouns

    Directory of Open Access Journals (Sweden)

    Silvia Cacchiani

    2011-05-01

    Full Text Available Italian has recently witnessed a steady increase in the use of unfamiliar lexical blends from names and nouns. While they serve an identificatory and descriptive function (in the sense of Anderson 2007, blends are created in extragrammatical morphology with careful attention to the semantic concepts encoded by the individual SWs, understanding blends from names and nouns depends on the decoder's direct or surrogate experience of the related reference. Significantly, blends are coined out of the need to be relevant (Sperber/Wilson 1990 and show various degrees of morphotactic and morphosemantic transparency (Thornton 1986; Dressler 1987, 1999, which makes them memorable (Lehrer 2003. In this paper we therefore address blends from names and nouns within the framework of the Naturalness Theory (Thornton 1986; Dressler et al. 1987; Dressler 1999. As will be seen, although blends are not created in rule-based grammars, some overall preferences and regularities can be observed for more core items (cf. Bat-El/Cohen, in press, within the framework of Optimality Theory under the principle of saliency (Dressler 1987. Focusing on their morphosyntactic transparency, we provide a typology of Italian unfamiliar blends from names and nouns functioning as naming units in order to delimit the category and reassess current typologies. While we allow for a continuum of morphotactic transparency within the prototypical category of extragrammatcial subtractive word-formations, we slightly adapt Ronneberger-Sibold (2006 and suggest we distinguish between blends on the one hand and the neighbouring category of clipped compounds on the other. Moving on to morphosemantic transparency and conceptual motivation, we use concepts from Cognitive Grammar, Cognitive Metaphor Theory and theories of Conceptual Blending (cf. Lakoff/Johnson 1980; Langacker 1987; Ruiz de Mendoza 1998, 2000; Kemmer 2003 to provide some preliminary remarks on specific subtypes, and blends from

  6. Preparation of Biodegradable Silk Fibroin/Alginate Blend Films for Controlled Release of Antimicrobial Drugs

    Directory of Open Access Journals (Sweden)

    Yaowalak Srisuwan

    2013-01-01

    Full Text Available Silk fibroin (SF/alginate blend films have been prepared for controlled release of tetracycline hydrochloride, an antimicrobial model drug. The blend films were analysed by Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, and UV-vis spectroscopy. The functional groups of the SF/alginate blends were monitored from their FTIR spectra. The homogeneity of the blend films was observed from SEM images. The dissolution and film transparency of the blend films depended on the SF/alginate blend ratio. The in vitro drug release profile of the blend films was determined by plotting the cumulative drug release versus time. It was found that the drug release significantly decreased as the SF/alginate blend ratio increased. The results demonstrated that the SF/alginate blend films should be a useful controlled-release delivery system for water-soluble drugs.

  7. 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.

  8. 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

  9. 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

  10. 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....

  11. Morphology and properties of PBT/SEBS and PBT/SEBS-G-MAH blends

    Science.gov (United States)

    Lu, Xiang; Qu, Jinping

    2016-03-01

    A series of poly (butylene terephthlate) (PBT)/ styrene-ethylene/butylene-styrene (SEBS) and PBT/ (styrene-ethylene/butylene-styrene)-G-(Maleic anhydride) (SEBS-G-MAH) blends were prepared by melt blending method. And the morphology, mechanical properties were studied to identify the effect of SEBS or SEBS-G-MAH weight fraction on the properties of blends. SEM show that the minor phase was hardly distinguishable in the blend of PBT/SEBS-G-MAH as the result of the improvement in dispersibility, compared with PBT/SEBS blends. These results lead to the different mechanical properties between PBT/SEBS and PBT/SEBS-G-MAH blends.

  12. 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.

  13. Influence of biodiesel blending on physicochemical properties and importance of mathematical model for predicting the properties of biodiesel blend

    International Nuclear Information System (INIS)

    Highlights: • Short identification of selected biodiesel feedstock. • Review of physicochemical properties for blended biodiesel. • Mathematical model for predicting properties of various biodiesel blends. - Abstract: The growing demand for green world serves as one of the most significant challenges of modernization. Requirements like largest usage of energy for modern society as well as demand for friendly milieu create a deep concern in field of research. Biofuels are placed at the peak of the research arena for their underlying benefits as mentioned by multiple researches. Out of a number of vegetable oils, only a few are used commercially for biodiesel production. Due to various limitations of edible oil, non-edible oils are becoming a profitable choice. Till today, very little percentage of biodiesel is used successfully in engine. The research is still continuing for improving the biodiesel usage level. Recently, it is found that the blended biodiesel from more than one feedstock provides better performance in engine. This paper reviews the physicochemical properties of different biodiesel blends obtained from various feedstocks with a view to properly understand the fuel quality. Moreover, a short description of each feedstock is given along with graphical presentation of important properties for various blend percentages from B0 to B100. Finally, mathematical model is formed for predicting various properties of biodiesel blend with the help of different research data by using polynomial curve fitting method. The results obtained from a number of literature based on this work shows that the heating value of biodiesel is about 11% lower than diesel except coconut (14.5% lower) whereas kinematic viscosity is in the range of 4–5.4 mm2/s. Flash point of all biodiesels are more than 150 °C, except neem and coconut. Cold flow properties of calophyllum, palm, jatropha, moringa are inferior to others. This would help to determine important properties of

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Acceptor blending ratio dependence of bulk heterojunction organic photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Haebong; Im, Chan; An, Jongdeok; Lee, Sunae; Park, Hoon [Konkuk University, Seoul (Korea, Republic of)

    2014-03-15

    Bulk heterojunction (BHJ) organic photovoltaic (OPV) devices are generally composed of a blend film of a π-conjugated polymeric electron donor and a C{sub 60} derivative electron acceptor intercalated between an anode and a cathode, typical of a two-dimensional device structure. Often, a regioregular poly(3-hexylthiophene) (rr-P3HT) and indene-C{sub 60} bisadduct (ICBA) blend film is used as the BHJ active layer instead of the conventional P3HT and phenyl-C{sub 61}-butyric acid methyl ester (PCBM) blend film due to the ICBA device's higher power conversion efficiency (PCE), which is correlated with its higher open-circuit voltage (V{sub OC} ). To determine the quantitative influences of those electron acceptors in the BHJ OPV devices, we prepared various devices of acceptors, either PCBM or ICBA, with a wide range of blending ratios (from 0 to 100%) for estimating their typical optoelectronic properties, e.g., UV-visible absorption spectra, photoluminescence intensity, surface morphology, and photovoltaic device parameters. Obtained data were compared to each other and were analyzed as a function of their acceptor blending ratio.

  20. Non-Isothermal Crystallization of PET/PLA Blends

    Science.gov (United States)

    Chen, Huipeng; Pyda, Marek; Cebe, Peggy

    2011-03-01

    Binary blends of poly(ethylene terephthalate) with poly(lactic acid), PET/PLA, were studied by differential scanning calorimetry. The solution cast blends were miscible in the melt over the entire composition range. We report the non-isothermal crystallization of: a.) PET, with and without presence of PLA crystals, and b.) PLA, with and without presence of PET crystals. PET can crystallize in all blends, regardless of whether PLA is amorphous or crystalline, and crystallinity of PET decreases as PLA content increases. PLA crystallization is strongly affected by the mobility of the PET. When PET is wholly amorphous, PLA can crystallize weakly even in 70/30 blends. When PET is crystalline, PLA cannot crystallize when its own content is below 0.90. The different behaviors may be related to the tendency of each polymer to form constrained chains, i.e., to form rigid amorphous fraction, RAF. PET is capable of forming a large amount of RAF, whereas relatively smaller amount of RAF forms in PLA. Like the crystals, rigid amorphous fraction of one component may inhibit growth of crystals of the other blend partner. Supported by the National Science Foundation, Polymers Program of the Division of Materials Research under DMR-0602473 and the MRI Program under DMR-0520655.

  1. The Viscoelastic Behavior of Polymer/Oligomer Blends

    Science.gov (United States)

    Zheng, Wei; McKenna, Gregory; Simon, Sindee

    2009-03-01

    The dynamics in athermal blends of poly(α-methyl styrene) (PaMS) and its short chain oligomer are investigated using rheometry and differential scanning calorimetry (DSC). Master curves for the dynamic shear responses, G' and G", are successfully constructed for both the pure materials and the blends, indicating the validity of the time-temperature superposition principle. The temperature dependence of the shift factor follows the WLF (Williams-Landel-Ferry) behavior over the temperature range studied, and for the blends, the dependence is dominated by the high mobility oligomer. The discrete relaxation spectra of the materials are calculated and are found to be broader for the blends than for the pure materials. A similar domination of the dynamics by the oligomer is observed in DSC enthalpy recovery studies and in the broadened glass transition from DSC. The ability to predict the dynamic responses of the blends from the responses of the neat materials is examined, and whether this prediction needs to incorporate the self-concentration idea as described in Colmenero's model will be discussed.

  2. Electrospun gelatin/polyurethane blended nanofibers for wound healing.

    Science.gov (United States)

    Kim, Sung Eun; Heo, Dong Nyoung; Lee, Jung Bok; Kim, Jong Ryul; Park, Sang Hyuk; Jeon, Seong Ho; Kwon, Il Keun

    2009-08-01

    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 microm. 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. PMID:19671952

  3. Electrospun gelatin/polyurethane blended nanofibers for wound healing

    International Nuclear Information System (INIS)

    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 μm. 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.

  4. 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.

  5. Blended implicit methods for the numerical solution of DAE problems

    Science.gov (United States)

    Brugnano, Luigi; Magherini, Cecilia; Mugnai, Filippo

    2006-05-01

    Recently, a new approach for solving the discrete problems, generated by the application of block implicit methods for the numerical solution of initial value problems for ODEs, has been devised [L. Brugnano, Blended block BVMs (B3VMs): a family of economical implicit methods for ODEs, J. Comput. Appl. Math. 116 (2000) 41-62; L. Brugnano, C. Magherini, Blended implementation of block implicit methods for ODEs, Appl. Numer. Math. 42 (2002) 29-45; L. Brugnano, D. Trigiante, Block implicit methods for ODEs, in: D. Trigiante (Ed.), Recent Trends in Numerical Analysis, Nova Science Publishers, New York, 2001, pp. 81-105]. This approach is based on the so-called blended implementation of the methods, giving corresponding blended implicit methods. The latter have been implemented in the computational code BiM [L. Brugnano, C. Magherini, The BiM code for the numerical solution of ODEs, J. Comput. Appl. Math. 164-165 (2004) 145-158]. Blended implicit methods are here extended to handle the numerical solution of DAE problems, resulting in a straightforward generalization of the basic approach.

  6. Techno- teaching convergence of blended learning: transitions and prospects

    Directory of Open Access Journals (Sweden)

    Osbaldo Turpo Gebera

    2013-12-01

    Full Text Available Since its emergence in the educational context, the Blended Learning emerges as 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, then advanced to integration, which resulted in the dilution of 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. The pedagogical and technological convergence of media and resources is a more consistent way to understand the mode, while providing a framework for interpreting the transition and development prospects of the Blended Learning, confluence and continuity and potential scenarios facing the same end: the training.

  7. Tests of blending and correlation of distillate fuel properties

    Science.gov (United States)

    Erwin, J.; Bowden, J. N.

    1982-01-01

    The development of a fuel test matrix, results from tests of several blends of distillate aircraft fuels, and the use of correlations in formulation determination during a NASA-sponsored program to identify new aircraft fuels are described. The program was initiated in order to characterize fuel blends which are appropriate for different types of combustors in use and under development. The fuels were required to feature a specified range of properties. Attention is given to fuel volatility, hydrogen content, aromatic content, freezing point, kinematic viscosity, and naphthalene content. Paraffinic and naphtenic base stocks were employed, using alkyl benzene, naphthene benzenes, and naphthalenes to adjust the blend properties. Categories for the test fuels comprised source-controlled and composition controlled fuels. Test results and compositions of various fuels are provided.

  8. 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.

  9. 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.

  10. 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.

  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. 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 .

  13. Photothermal and morphological characterization of PLA/PCL polymer blends

    Science.gov (United States)

    Correa-Pacheco, Z. N.; Jiménez-Pérez, J. L.; Sabino, M. A.; Cruz-Orea, A.; Loaiza, M.

    2015-09-01

    Nowadays, some synthetic polymers have been replaced by biodegradable polymers in order to avoid environmental contamination. Among these biodegradables polymers, aliphatic polyesters such as polylactic acid (PLA) and polycaprolactone (PCL) have been widely used. In the present study, solvent-casting films of PLA, PCL and polymer blends with and without compatibilizer (PLA grafted with maleic anhydride) were prepared. The thermal diffusivity ( α) of each sample was obtained by using the open photoacoustic cell technique. Morphology and thermal properties were determined by using scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry (DSC), respectively. The blends showed lower thermal diffusivity compared to pure polymers. However, when the compatibilizer was used, the highest value of thermal diffusivity was obtained. Also, cold crystallization with the highest value of enthalpy of fusion was observed for the compatibilized sample, which was revealed by DSC. To our knowledge, this is the first time that the thermal diffusivity of these biodegradable polymer blends is reported.

  14. 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.

  15. Certification of alternative aviation fuels and blend components

    Energy Technology Data Exchange (ETDEWEB)

    Wilson III, George R. (Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States)); Edwards, Tim; Corporan, Edwin (United States Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States)); Freerks, Robert L. (Rentech, Incorporated, 1331 17th Street, Denver, Colorado 80202 (United States))

    2013-01-15

    Aviation turbine engine fuel specifications are governed by ASTM International, formerly known as the American Society for Testing and Materials (ASTM) International, and the British Ministry of Defence (MOD). ASTM D1655 Standard Specification for Aviation Turbine Fuels and MOD Defence Standard 91-91 are the guiding specifications for this fuel throughout most of the world. Both of these documents rely heavily on the vast amount of experience in production and use of turbine engine fuels from conventional sources, such as crude oil, natural gas condensates, heavy oil, shale oil, and oil sands. Turbine engine fuel derived from these resources and meeting the above specifications has properties that are generally considered acceptable for fuels to be used in turbine engines. Alternative and synthetic fuel components are approved for use to blend with conventional turbine engine fuels after considerable testing. ASTM has established a specification for fuels containing synthesized hydrocarbons under D7566, and the MOD has included additional requirements for fuels containing synthetic components under Annex D of DS91-91. New turbine engine fuel additives and blend components need to be evaluated using ASTM D4054, Standard Practice for Qualification and Approval of New Aviation Turbine Fuels and Fuel Additives. This paper discusses these specifications and testing requirements in light of recent literature claiming that some biomass-derived blend components, which have been used to blend in conventional aviation fuel, meet the requirements for aviation turbine fuels as specified by ASTM and the MOD. The 'Table 1' requirements listed in both D1655 and DS91-91 are predicated on the assumption that the feedstocks used to make fuels meeting these requirements are from approved sources. Recent papers have implied that commercial jet fuel can be blended with renewable components that are not hydrocarbons (such as fatty acid methyl esters). These are not allowed blend

  16. 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.

  17. 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.

  18. Optimal control of blending and melting of copper concentrates

    Science.gov (United States)

    Imanbekova, Ulzhan; Hotra, Oleksandra; Koshimbayev, Shamil; Popiel, Piotr; Tanaś, Jacek

    2015-09-01

    The mathematical models of the melting process, the optimization criterion and constraints on the input and controlling variables and the values of the conductivities of the melt under the electrodes and the phase voltages are used to solve the optimization problem of the electrical regime of the electric furnace. In this paper the optimal variant of the electrical regime of the furnace for the electromelting and blending processing of copper concentrates is considered, which can be provided by the optimal immersion of electrodes. The optimal parameters of the technological process of electromelting and blending are calculated. The proposed mathematical model could be applied for melting process optimization.

  19. 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.

  20. 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...

  1. Polypropylene-polyethylene blends modified by gamma radiation

    International Nuclear Information System (INIS)

    One way to obtain a better mechanical property of polypropylene and polyethylene is to increasing the number of polymer chains cross-linked by gamma radiation. After irradiation a network is formed as a result of various chemical reactions and the radicals formed are concentrated in the amorphous phase. With the objective to improve the mechanical properties of PP, blends with PE were prepared and irradiated in doses up to 500 kGy, in atmospheric ambient. The molecular characterization of the blends was made by infrared spectroscopy and the data showed an increase in rigidity and a unique behaviour in Izod impact resistance. (author)

  2. 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...

  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...... of biodiesel, regardless of the concentration used. This observation leads to the conclusion that blending with biodiesel does not impact the long-term biodegradation of specific diesel oil fractions. © 2013 Elsevier Ltd. All rights reserved....

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

    OpenAIRE

    Robert L. Shambaugh, Ph.D; Diana L. Ortiz

    2007-01-01

    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 t...

  5. Polymer blends for LDB applications. [Long Duration Ballooning

    Science.gov (United States)

    Lichkus, Andrew M.; Harrison, Ian R.

    1991-01-01

    A series of LCP/PE blends have been studied to determine the potential of such systems to produce a high modulus balloon film material which retains the balloon fabrication and low temperature flight advantages of the current PE films. Blown films of blends of 5 and 15 percent LCP in PE have been produced which show a 28 percent enhancement in modulus over the neat PE matrix. These results are substantially lower than anticipated and are explained in terms of the LCP reinforcement aspect ratio and fibril diameter.

  6. Pore structure and carbonation in blended lime-cement pastes

    OpenAIRE

    Álvarez, J. I.; Arandigoyen, M.

    2006-01-01

    The present study aims to gain a fuller understandingof the curing process in lime pastes (100, 90, 80, 70,60, 50 and 40% lime) blended with cement by analyzingcarbonation in these materials. A hydrated, airslaked lime powder and CEM II A/L 32.5 Portlandcement were used for the blends. These materialswere singled out for research primarily because theymay be used in the restoration of heritage monuments.Variation in weight was used as an indicator for carbonation.A new parameter, A, was found...

  7. Blended Learning in Real Estate Education: A Survey

    OpenAIRE

    Thomson, B; Martens, B.

    2015-01-01

    Blended learning is to regarded a didactical meaningful combination of traditional face-to-face instruction and state-of-the-art e-learning formats. The efficiency and flexibility of computer-mediated forms of learning are combined with the social aspects of face-to-face communication. In other words a useful learning arrangement which combines modern-day means of networking through the internet and ‘classical’ learning methods and media. At the time of writing, blended learning has been oper...

  8. 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...

  9. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Science.gov (United States)

    2010-01-01

    ... maintained in a clean condition and free of flies, insects, and rodents. The drying, blending, and packaging... and accessories. (b) Dry blending of edible egg products, including adding edible dry ingredients,...

  10. 76 FR 78290 - Cooperative Research and Development Agreement: Usage of Biodiesel Fuel Blends Within Marine...

    Science.gov (United States)

    2011-12-16

    ... Register (73 FR 3316). Cooperative Research and Development Agreements Cooperative Research and Development... 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...

  11. 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.

  12. Preparation and Characterization of Chitosan/Agar Blended Films: Part 2. Thermal, Mechanical, and Surface Properties

    OpenAIRE

    Elhefian, Esam. A.; Mohamed Mahmoud NASEF; Yahaya, Abdul Hamid

    2012-01-01

    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...

  13. Anomalous Molecular Weight Dependence of Chain Dynamics in Unentangled Polymer Blends with Strong Dynamic Asymmetry

    OpenAIRE

    Arrese-Igor, Silvia; Alegría, Ángel; Moreno Segurado, Ángel J.; Colmenero de León, Juan

    2011-01-01

    We address the general question of how the molecular weight dependence of chain dynamics in unentangled polymers is modified by blending. By dielectric spectroscopy we measure the normal mode relaxation of polyisoprene in blends with a slower component of poly(ter-butylstyrene). Unentangled polyisoprene in the blend exhibits strong deviations from Rouse scaling, approaching 'entangled-like' behavior at low temperatures in concomitance with the increase of the dynamic asymmetry in the blend. T...

  14. Towards a Blended Learning Model for Teaching and Learning Computer Programming: A Case Study

    OpenAIRE

    Said HADJERROUIT

    2008-01-01

    Blended learning is becoming an attractive model in higher education as new innovative information technologies are becoming increasingly available. However, just blending face-to-face learning with information technologies cannot provide effective teaching and efficient solutions for learning. To be successful, blended learning must rely on solid learning theory and pedagogical strategies. In addition, there is a need for a design-based research approach to explore blending learning through ...

  15. What Is The Hoopla About Blended Learning: Something Old Is New Again

    OpenAIRE

    Hassan Rastegarpour

    2011-01-01

    The recent focus on blended learning has led so many educationalists in corporate training and academia to believe that a new educational phenomenon has been discovered. In reality, the blending of face-to-face instruction with various types of non-classroom technology mediated delivery has been practiced within the academic and non academic environments for more than four decades. Who does really want to know the real story of blended learning? Blended learning sounds like a nice idea- mixi...

  16. Blended learning experience in teacher education: the trainees´ perspective

    OpenAIRE

    Monika Černá

    2009-01-01

    The article deals with blended learning in the context of pre-graduate English language teacher education. Firstly, the concept of blended learning is defined, then, the attention is focused on the online component of a blend, namely on the issue of interpersonal interaction including the challenges, which learning through online networking poses. Finally, results of a small–scale research are provided to offer insights into teacher trainees´ perspective of the blended learning experience at ...

  17. Literature Review in Conceptions and Approaches to Teaching using Blended Learning

    OpenAIRE

    Vicki Caravias

    2015-01-01

    This paper presents a critical review and synthesis of research literature in higher education exploring teachers' conceptions of blended learning and their approaches to both design and teaching. Definitions of blended learning and conceptual frameworks are considered first. Attention is given to Picciano's Blending with Purpose Multimodal framework. This paper builds upon previous research on blended learning and conceptual framework by Picciano (A. Picciano, 2009) by exploring how objectiv...

  18. Significant Enhancement of Mechanical and Thermal Properties of Thermoplastic Polyester Elastomer by Polymer Blending and Nanoinclusion

    OpenAIRE

    Manwar Hussain; Young Hui Ko; Yong Ho Choa

    2016-01-01

    Thermoplastic elastomer composites and nanocomposites were fabricated via melt processing technique by blending thermoplastic elastomer (TPEE) with poly(butylene terephthalate) (PBT) thermoplastic and also by adding small amount of organo modified nanoclay and/or polytetrafluoroethylene (PTFE). We study the effect of polymer blending on the mechanical and thermal properties of TPEE blends with and without nanoparticle additions. Significant improvement was observed by blending only TPEE and v...

  19. Evaluation of non-linear blending in dual-energy computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, David R. [Biomedical Imaging Resource, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905 (United States)], E-mail: holmes.david3@mayo.edu; Fletcher, Joel G. [Department of Radiology, Mayo Clinic College of Medicine (United States); Apel, Anja [Siemens Medical Solutions USA, Inc. (United States); Huprich, James E.; Siddiki, Hassan; Hough, David M. [Department of Radiology, Mayo Clinic College of Medicine (United States); Schmidt, Bernhard [Siemens Medical Solutions USA, Inc. (United States); Flohr, Thomas G. [Department of Radiology, Mayo Clinic College of Medicine (United States); Robb, Richard [Biomedical Imaging Resource, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905 (United States); McCollough, Cynthia; Wittmer, Michael [Department of Radiology, Mayo Clinic College of Medicine (United States); Eusemann, Christian [Siemens Medical Solutions USA, Inc. (United States)

    2008-12-15

    Dual-energy CT scanning has significant potential for disease identification and classification. However, it dramatically increases the amount of data collected and therefore impacts the clinical workflow. One way to simplify image review is to fuse CT datasets of different tube energies into a unique blended dataset with desirable properties. A non-linear blending method based on a modified sigmoid function was compared to a standard 0.3 linear blending method. The methods were evaluated in both a liver phantom and patient study. The liver phantom contained six syringes of known CT contrast which were placed in a bovine liver. After scanning at multiple tube currents (45, 55, 65, 75, 85, 95, 105, and 115 mAs for the 140-kV tube), the datasets were blended using both methods. A contrast-to-noise (CNR) measure was calculated for each syringe. In addition, all eight scans were normalized using the effective dose and statistically compared. In the patient study, 45 dual-energy CT scans were retrospectively mixed using the 0.3 linear blending and modified sigmoid blending functions. The scans were compared visually by two radiologists. For the 15, 45, and 64 HU syringes, the non-linear blended images exhibited similar CNR to the linear blended images; however, for the 79, 116, and 145 HU syringes, the non-linear blended images consistently had a higher CNR across dose settings. The radiologists qualitatively preferred the non-linear blended images of the phantom. In the patient study, the radiologists preferred non-linear blending in 31 of 45 cases with a strong preference in bowel and liver cases. Non-linear blending of dual energy data can provide an improvement in CNR over linear blending and is accompanied by a visual preference for non-linear blended images. Further study on selection of blending parameters and lesion conspicuity in non-linear blended images is being pursued.

  20. Development And Testing Of Biogas-Petrol Blend As An Alternative Fuel For Spark Ignition Engine

    OpenAIRE

    Awogbemi; Omojola; Adeyemo,, Adebowale; Sunday Babatunde

    2015-01-01

    Abstract This research is on the development and testing of a biogas-petrol blend to run a spark ignition engine. A2080 ratio biogaspetrol blend was developed as an alternative fuel for spark ignition engine test bed. Petrol and biogas-petrol blend were comparatively tested on the test bed to determine the effectiveness of the fuels. The results of the tests showed that biogas petrol blend generated higher torque brake power indicated power brake thermal efficiency and brake mean effective p...

  1. 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 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.

  2. 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.

  3. 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...

  4. 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…

  5. 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,…

  6. 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…

  7. 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,…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  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. 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…

  16. 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...

  17. Transitioning an Adult-Serving University to a Blended Learning Model

    Science.gov (United States)

    Korr, Jeremy; Derwin, Ellen Baker; Greene, Kimberly; Sokoloff, William

    2012-01-01

    While many institutions deliver some classes in blended format, Brandman University transitioned all of its face-to-face classes to blended delivery, using a model tailored to the needs of adult learners. This article provides research supporting the ways that blended learning principles align with key principles of andragogy. The article provides…

  18. Blended Learning: Investigating Its Potential in an English Language Teacher Training Program

    Science.gov (United States)

    Kocoglu, Zeynep; Ozek, Yesim; Kesli, Yesim

    2011-01-01

    Although the benefits of blended learning have been well documented in educational research, relatively few studies have examined blended learning in language teacher education. This study discusses a blended learning approach for a teacher training program designed for in-service English language teachers, and investigates its effectiveness by…

  19. Blended Learning Experience in Teacher Education: The Trainees' Perspective

    Science.gov (United States)

    Cerná, Monika

    2009-01-01

    The article deals with blended learning in the context of pre-graduate English language teacher education. Firstly, the concept of blended learning is defined, then, the attention is focused on the online component of a blend, namely on the issue of interpersonal interaction including the challenges, which learning through online networking poses.…

  20. Effective Blended Learning Practices: Evidence-Based Perspectives in ICT-Facilitated Education

    Science.gov (United States)

    Stacey, Elizabeth, Ed.; Gerbic, Philippa, Ed.

    2009-01-01

    New innovations of online learning within blended environments create a need within academia for research on best practices in teaching. This book provides insight into the practice of blended learning in higher education. This unique book collects new international research into many aspects of blended learning from the perspectives of learners,…

  1. Applying TSOI Hybrid Learning Model to Enhance Blended Learning Experience in Science Education

    Science.gov (United States)

    Tsoi, Mun Fie

    2009-01-01

    Purpose: Research on the nature of blended learning and its features has led to a variety of approaches to the practice of blended learning. The purpose of this paper is to provide an alternative practice model, the TSOI hybrid learning model (HLM) to enhance the blended learning experiences in science education. Design/methodology/approach: The…

  2. Film-forming properties of castor oil polyol ester blends in elastohydrodynamic conditions

    Science.gov (United States)

    The viscosities and elastohydrodynamic (EHD) film thickness properties of binary blends of castor oil with polyol esters were determined experimentally. Predicted blend viscosity was calculated from the viscosity of the pure blend components. Measured viscosity values were closer to the values pre...

  3. 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…

  4. 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…

  5. 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…

  6. 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.

  7. 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…

  8. Optical and thermal studies of starch/methylcellulose blends

    Science.gov (United States)

    Ragab, H. S.; Abd El-Kader, M. F. H.

    2013-02-01

    Starch and methylcellulose (MC) homopolymers and their blends were prepared using a casting technique. The samples were investigated by infrared (Fourier transform infrared (IR)), ultraviolet/visible (UV/VIS), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Significant changes in IR spectra of blend samples were observed, which indicated the occurrence of an intermolecular interactions between starch and MC. UV/VIS analyses revealed that the values of the optical band gap decreased with increasing MC content in blend samples. The positions of the investigated samples on the chromaticity diagram and the color parameters, such as L*, U*, V*, C*, hue and Ye, reflected the presence of a high color gradient and were composition dependent. A single glass transition temperature for each poly-blend sample was observed, which supported the existence of compatibility in such a system. The kinetic thermodynamic parameters, such as activation energy, enthalpy, entropy and Gibbs free energy, were evaluated from thermogravimetric analysis data using the Coats-Redfern relation.

  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. 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…

  11. 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…

  12. 40 CFR 80.69 - Requirements for downstream oxygenate blending.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Requirements for downstream oxygenate... downstream oxygenate blending. The requirements of this section apply to all reformulated gasoline blendstock... annual compliance period; (D) A process for notifying oxygenate blenders and other downstream parties...

  13. 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.

  14. Blended Learning: The Perceptions of First-Year Geography Students

    Science.gov (United States)

    Mitchell, Phillipa; Forer, Pip

    2010-01-01

    Focusing on "Digital Worlds", a first-year geography blended learning course at the University of Auckland, this paper gives voice to the students, examining how they perceived e-learning versus traditional learning mechanisms; how e-learning mechanisms have affected their learning behaviour; and why certain e-learning mechanisms offered in the…

  15. 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

  16. 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.

  17. Biodiesel/ULSD blend ratios by analysis of fuel properties

    Science.gov (United States)

    Biodiesel is an alternative fuel that is made from vegetable oil or animal fat. Biodiesel is often blended with ultra low sulfur diesel (ULSD; 15 mg/kg maximum sulfur content) in volumetric ratios (VBD) of up to 20 vol% (B20). Government tax credits and other regulatory requirements may depend on ac...

  18. Chitosan/Poly(ɛ-caprolactone) blend scaffolds for cartilage repair

    NARCIS (Netherlands)

    Neves, Sara C.; Moreira Teixeira, Liliana S.; Moroni, Lorenzo; Reis, Rui L.; Blitterswijk, van Clemens A.; Alves, Natália M.; Karperien, Marcel; Mano, João F.

    2011-01-01

    Chitosan (CHT)/poly(ɛ-caprolactone) (PCL) blend 3D fiber-mesh scaffolds were studied as possible support structures for articular cartilage tissue (ACT) repair. Micro-fibers were obtained by wet-spinning of three different polymeric solutions: 100:0 (100CHT), 75:25 (75CHT) and 50:50 (50CHT) wt.% CHT

  19. 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…

  20. 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…

  1. 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…

  2. 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

  3. 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.

  4. 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"…

  5. 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…

  6. 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…

  7. 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…

  8. 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.

  9. Mapping Cultural Frame Shifting in Interaction Design with Blending Theory

    DEFF Research Database (Denmark)

    Markussen, Thomas; Krogh, Peter Gall

    2008-01-01

    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...

  10. 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...

  11. 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…

  12. 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…

  13. Blended Learning: Communication, Locations and Work-Life Practices

    Science.gov (United States)

    Moe, Carl Erik; Rye, Stale Angen

    2011-01-01

    The article discusses blended learning and how various delivery formats affect the way learning is situated in work-life practices. The authors approached this issue through an empirical study of an in-service training programme for middle-level managers in a number of case organisations. The programme used a combination of e-learning, textbooks…

  14. 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.

  15. Alternative Assessment Techniques for Blended and Online Courses

    Science.gov (United States)

    Litchfield, Brenda C.; Dempsey, John V.

    2013-01-01

    Alternative assessment techniques are essential for increasing student learning in blended and online courses. Rather than simply answer multiple-choice questions, students can choose activities in an academic contract. By using a contract, students will be active participants in their own learning. Contracts add a dimension of authenticity to…

  16. 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

  17. 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…

  18. 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.

  19. Blends of caprolactam/caprolactone copolymers and chlorinated polymers

    NARCIS (Netherlands)

    Alberda van Ekenstein, G.O.R.; Deuring, H.; ten Brinke, G.; Ellis, T.S.

    1997-01-01

    The phase behaviour of blends of chlorinated polyethylene, polyvinyl chloride (PVC) and chlorinated PVC with random copolymers of caprolactone and caprolactam has been investigated and the results correlated with a binary interaction model. The known miscibility of polycaprolactone in the chlorinate

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    Thermal composition fluctuations in homopolymer mer blends and diblock copolymers were studied with SANS in varying pressure and temperature fields. For homopolymers we find a quite consistent behavior: The dominating effect of compressibility or packing leads to a reduction of the entropic...

  1. 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.

  2. 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

  3. THERMOPLASTIC STARCH-KRAFT LIGNIN-GLYCEROL BLENDS

    Science.gov (United States)

    Starch-kraft lignin-glycerol blends were extruded in a twin-screw extruder to produce non-brittle films. One week after extrusion, films with a mid-range composition of 52% starch, 20% lignin, and 28% glycerol showed a tensile strength at break of 2.8 MPa, Young's modulus of 48 MPa, and elongation ...

  4. Conditioning Factors for Group Management in Blended Learning Scenarios

    OpenAIRE

    Pérez-Sanagustín, Mar; Hernández-Leo, Davinia; Blat, Josep

    2009-01-01

    Pérez-Sanagustín, M., Hernández-Leo D., & Blat, J. (accepted). Conditioning Factors for Group Management in Blended Learning Scenarios. The 9th IEEE International Conference on Advanced Learning Technologies. July, 14-18, 2009, Riga, Latvia.

  5. Team Learning and Collaboration between Online and Blended Learner Groups

    Science.gov (United States)

    Lim, Doo Hun; Yoon, Seung Won

    2008-01-01

    In an effort to compare team-level learning performance resulting from different instructional variables and settings, this study examined how online and blended delivery learner groups compared in terms of learning outcomes, collaboration, and perceived quality of instructional variables. Results indicated that the two teams were not different in…

  6. Role Taking and Knowledge Building in a Blended University Course

    Science.gov (United States)

    Cesareni, Donatella; Cacciamani, Stefano; Fujita, Nobuko

    2016-01-01

    Role taking is an established approach for promoting social cognition. Playing a specific role within a group could lead students to exercise collective cognitive responsibility for collaborative knowledge building. Two studies explored the relationship of role taking to participation in a blended university course. Students participated in the…

  7. Performance Test of Engine Fuelled With Diesel and Ethanol Blends.

    Directory of Open Access Journals (Sweden)

    B.K.L.Murthy

    2015-04-01

    Full Text Available Environmental concerns and limited amount of petroleum fuels have caused interests in the development of alternative fuels for internal combustion (ICengines. As an alternative, biodegradable and renewable fuel, ethanol is receiving increasing attention. An experimental investigation on the application of the blends of ethanol with diesel to a diesel engine was carried out. First the solubility of ethanol and diesel was conducted with and without the additive of normal butanol (n-butanol. The purpose of this project is to find the optimum percentage of ethanol that gives simultaneously better performance and lower emissions. The experiments were conducted on a water-cooled single-cylinder Direct Injection (DI diesel engine using 0% (neat diesel fuel, 10% (E10-D, 15%(E15–D, 20% (E20–D, and 25%(E25–D ethanol–diesel blended fuels. Experimental tests were carried out to study the performance of the engine fuelled with the blends compared with those fuelled by diesel. The test results show that it is feasible and applicable for the blends with n-butanol to replace pure diesel as the fuel for diesel engine.

  8. 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...

  9. 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…

  10. 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.

  11. 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. PMID:27482842

  12. Constructs Related to Community College Student Satisfaction in Blended Learning

    Science.gov (United States)

    Sorden, Stephen D.; Munene, Ishmael I.

    2013-01-01

    This paper discusses the constructs of social presence, collaborative learning, computer-supported collaborative learning, and satisfaction in blended learning environments. It presents the results of a study that used the Collaborative Learning, Social Presence, and Satisfaction (CLSS) questionnaire, which was conducted on one campus in a…

  13. Design of a Blended Learning Environment: Considerations and Implementation Issues

    Science.gov (United States)

    Gedik, Nuray; Kiraz, Ercan; Ozden, M. Yasar

    2013-01-01

    This study identified critical issues in the design of a blended learning environment by examining basic design considerations and implementation issues. Following a design-based research approach with the phenomenological tradition of qualitative research, the study investigated instructor experiences relating to the design, development, and…

  14. Biodiesel/Petrodiesel blends: analytical determination of biodiesel percentage

    International Nuclear Information System (INIS)

    Analysis of biodiesel/petrodiesel blends is of interest both for technical and fiscal reasons. Several methods have been developed to carried out this kind of analysis, most of team based on chromatographic and spectroscopic techniques. Recently, a new method based on natural abundance radiocarbon analysis has been proposed and validated and could be extended for more complex samples

  15. Study of the Blending Efficiency of Pitched Blade Impellers

    Directory of Open Access Journals (Sweden)

    I. Fořt

    2001-01-01

    Full Text Available This paper presents an analysis of the blending efficiency of pitched blade impellers under a turbulent regime of flow of an agitated low viscous liquid. The conductivity method is used to determine of the blending (homogenization time of miscible liquids in pilot plant mixing equipment with standard radial baffles. For the given homogeneity degree (98 % a three-blade pitched blade impeller is tested with various off-bottom clearances, vessel/ impeller diameter ratios and various impeller pitch angles. The experimental results show in accordance with theoretical data from the literature, that the greatest effect on the dimensionless blending time is exhibited by the vessel/ impeller diameter ratio and the impeller pitch angle. The number of total circulations necessary for reaching the chosen homogeneity degree depends on the impeller pitch angle and amounts more than three. Finally, the energetic efficiency of the blending process is calculated. The results of this study show, that the highest energetic efficiency of the three-blade pitched blade impeller appears for the pitch angle a = 24°, the impeller/vessel diameter ratio T/D = 2 and the impeller off-bottom clearance h/D = 1.

  16. 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...

  17. An on-line gasoline blending system put into production

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Anew system for online gasoline blending, which was developed by researchers from the CAS Institute of Automation (CASIA), has been put into production at China Petrochemical Corporation (SINOPEC) and PetroChina Corporation. It is expected to thoroughly renovate the technology in this regard and achieve maximal economic benefits in oil production stage.

  18. 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...

  19. 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

  20. 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…

  1. 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. PMID:21117636

  2. 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. PMID:25051621

  3. 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

  4. 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…

  5. A spatial-temporal-spectral blending model using satellite images

    Science.gov (United States)

    Zhang, L.; Fu, D.; Sun, X.; Chen, H.; She, X.

    2016-04-01

    Due to the budget and technical limitations, remote sensing sensor designs trade spatial resolution, swath width and spectral resolution. Consequently, no sensor can provide high spatial resolution, high temporal resolution and high spectral resolution simultaneously. However, the ability of Earth observation at fine resolution is urgently needed for global change science. One possible solution is to “blend” the reflectance from a variety of satellite data sources, including those providing high spatial resolution and less frequent coverage (e.g., Landsat Thematic Mapper, TM), daily global data (e.g., Moderate Resolution Imaging Spectroradiometer, MODIS), and high spectral resolution and infrequent revisit cycle (e.g., Hyperion). However, the previous algorithms for blending multi-source remotely sensed data have some shortcomings, especially with regard to hyperspectral information. This study has developed a SPAtial-Temporal-Spectral blending model (SPATS) that can simulate surface reflectance with high spatial-temporal-spectral resolution. SPATS is based on an existing spatial-temporal image blending model and a spatial-spectral image blending model. The performance of SPATS was tested with both simulated and observed satellite data, using Landsat TM, Hyperion and MODIS data, as well as heterogeneous landscapes as examples. The results show that the high spatial-temporal-spectral resolution reflectance data can be applied to investigations of global landscapes that are changing at different temporal scales.

  6. 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…

  7. Identification of Telomerase-activating Blends From Naturally Occurring Compounds.

    Science.gov (United States)

    Ait-Ghezala, Ghania; Hassan, Samira; Tweed, Miles; Paris, Daniel; Crynen, Gogce; Zakirova, Zuchra; Crynen, Stefan; Crawford, Fiona

    2016-06-01

    Context • Telomeres are repeated deoxyribonucleic acid (DNA) sequences (TTAGGG) that are located on the 5' ends of chromosomes, and they control the life span of eukaryotic cells. Compelling evidence has shown that the length of a person's life is dictated by the limited number of times that a human cell can divide. The enzyme telomerase has been shown to bind to and extend the length of telomeres. Thus, strategies for activating telomerase may help maintain telomere length and, thus, may lead to improved health during aging. Objective • The current study intended to investigate the effects of several natural compounds on telomerase activity in an established cell model of telomere shortening (ie, IMR90 cells). Design • The research team designed an in vitro study. Setting • The study was conducted at Roskamp Institute in Sarasota, FL, USA. Intervention • The tested single compounds were (1) α-lipoic acid, (1) green tea extract, (2) dimethylaminoethanol L-bitartrate (DMAE L-bitartrate), (3) N-acetyl-L-cysteine hydrochloride (HCL), (4) chlorella powder, (5) L-carnosine, (6) vitamin D3, (7) rhodiola PE 3%/1%, (8) glycine, (9) French red wine extract, (10) chia seed extract, (11) broccoli seed extract, and (12) Astragalus (TA-65). The compounds were tested singly and as blends. Outcome Measures • Telomerase activity for single compounds and blends of compounds was measured by the TeloTAGGG telomerase polymerase chain reaction (PCR) enzyme-linked immunosorbent assay (ELISA). The 4 most potent blends were investigated for their effects on cancer-cell proliferation and for their potential effects on the cytotoxicity and antiproliferative activity of a chemotherapeutic agent, the topoisomerase I inhibitor topotecan. The benefits of 6 population doublings (PDs) were measured for the single compounds, and the 4 blends were compared to 3 concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Results • Certain of the compounds increased

  8. Performance of jatropha oil blends in a diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Forson, F.K.; Oduro, E.K.; Hammond-Donkoh, E. [Kwame Nkrumah University of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

    2004-06-01

    Results are presented on tests on a single-cylinder direct-injection engine operating on diesel fuel, jatropha oil, and blends of diesel and jatropha oil in proportions of 97.4%/2.6%; 80%120%; and 50%150% by volume. The results covered a range of operating loads on the engine. Values are given for the chemical and physical properties of the fuels, brake specific fuel consumption, brake power, brake thermal efficiency, engine torque, and the concentrations of carbon monoxide, carbon dioxide and oxygen in the exhaust gases. Carbon dioxide emissions were similar for all fuels, the 97.4% diesel/2.6% jatropha fuel blend was observed to be the lower net contributor to the atmospheric level. The trend of carbon monoxide emissions was similar for the fuels but diesel fuel showed slightly lower emissions to the atmosphere. The test showed that jatropha oil could be conveniently used as a diesel substitute in a diesel engine. The test further showed increases in brake thermal efficiency, brake power and reduction of specific fuel consumption for jatropha oil and its blends with diesel generally, but the most significant conclusion from the study is that the 97.4% diesel/2.6% jatropha fuel blend produced maximum values of the brake power and brake thermal efficiency as well as minimum values of the specific fuel consumption. The 97.4%12.6% fuel blend yielded the highest cetane number and even better engine performance than the diesel fuel suggesting that jatropha oil can be used as an ignition- accelerator additive for diesel fuel. (author)

  9. Miscibility and Morphology of Poly(lactic ACID)/POLY(Β-HYDROXYBUTYRATE) Blends

    Science.gov (United States)

    Tri Phuong, Nguyen; Guinault, Alain; Sollogoub, Cyrille

    2011-01-01

    The miscibility and morphology of poly(lactic)acid (PLA)/polyβ-hydroxybutyrate (PHB) prepared by melt blending method were investigated by Fourier transform infrared (FTIR), Differential scanning calorimetry (DSC), melt rheology and scanning electron microscopy (SEM) observations. FTIR and DSC methods present some limits to examine the miscibility state of PLA/PHB blends. This drawback can be overcome with the Cole-Cole method by observing the η" = f(η') curves to confirm the miscibility of semicrystalline PLA/ semicrystalline PHB blends. MEB micrographs of fractured surface of blends were also used to investigate the miscibility of these blends.

  10. 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.

  11. Translating Knowledge through Blended Learning: A Comparative Analysis of Face-to-Face and Blended Learning Methods

    Science.gov (United States)

    Golden, Thomas P.; Karpur, Arun

    2012-01-01

    This study is a comparative analysis of the impact of traditional face-to-face training contrasted with a blended learning approach, as it relates to improving skills, knowledge and attitudes for enhancing practices for achieving improved employment outcomes for individuals with disabilities. The study included two intervention groups: one…

  12. 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.

  13. 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.

  14. 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.

  15. Comparison of Model Reliabilities from Single-Step and Bivariate Blending Methods

    DEFF Research Database (Denmark)

    Taskinen, Matti; Mäntysaari, Esa; Lidauer, Martin;

    2013-01-01

    Model based reliabilities in genetic evaluation are compared between three methods: animal model BLUP, single-step BLUP, and bivariate blending after genomic BLUP. The original bivariate blending is revised in this work to better account animal models. The study data is extracted from the product......Model based reliabilities in genetic evaluation are compared between three methods: animal model BLUP, single-step BLUP, and bivariate blending after genomic BLUP. The original bivariate blending is revised in this work to better account animal models. The study data is extracted from...... be calculated. Model reliabilities by the single-step and the bivariate blending methods were higher than by animal model due to genomic information. Compared to the single-step method, the bivariate blending method reliability estimates were, in general, lower. Computationally bivariate blending method was......, on the other hand, lighter than the single-step method....

  16. 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

  17. 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.

  18. Mit Blended Learning zur effizienten Literatursuche / Blended Learning: a way to efficient literature search

    Directory of Open Access Journals (Sweden)

    Schubnell, Brigitte

    2007-12-01

    Full Text Available Since 2004 Information Literacy has been part of medical studies at the University of Zurich. The practical course “transfer of knowledge” takes place in the 2nd semester and is mandatory. In 2004 and 2005 the Main Library University of Zurich introduced the medical students, roughly 300, into the topic using a classic approach, i.e. by presentations and exercises. 32 double lessons were given by five employees of the Main Library. Evaluations showed that the students had only little interest in the topic and rated the course poorly. Among others, the following reasons were considered to explain the students’ weak motivation:lack of stimulation such as relevance for exams or other controls of performance limited possibilities to apply the gained knowledge in the 1st year of medical studies; thus students considered some contents irrelevant some exercises were not designed optimally, thereby challenging the students too little In the summer semester 2006 the course was given for the first time using blended learning. The goal was to increase the activity of the students and to make the contents available in the long term. The new form of teaching and learning has been a success and in 2007 the second round took place in the new mode. In the new course, students acquire the theory by self-study using an e-learning module. The period of self-study, which is finished by an online-test, is followed by a double lesson. This double lesson has the character of an exercise and is used to discuss problems and to consolidate the learnt contents using a given question. The e-learning module is freely accessible on the Virtual Education Platform Medicine (VAM.

  19. 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

  20. Investigations on the effects of ethanol–methanol–gasoline blends in a spark-ignition engine: Performance and emissions analysis

    OpenAIRE

    Ashraf Elfasakhany

    2015-01-01

    This study discusses performance and exhaust emissions from spark-ignition engine fueled with ethanol–methanol–gasoline blends. The test results obtained with the use of low content rates of ethanol–methanol blends (3–10 vol.%) in gasoline were compared to ethanol–gasoline blends, methanol–gasoline blends and pure gasoline test results. Combustion and emission characteristics of ethanol, methanol and gasoline and their blends were evaluated. Results showed that when the vehicle was fueled wit...