Reactive blending of polyamide 6,6 and Vectra A

In this paper, blends of Nylon 6,6 with the liquid crystal polymer Vectra A950 are considered; specifically we focused our attention on Nylon 6,6 modifications by interchange reactions that can occur in the melt, as a function of mixing conditions and blend compositions. Two matrix samples have been used, characterised by a slightly different relative amount of amine and carboxylic end groups, being the latter predominant in both cases. The dried polymers Nylon 6,6/Vectra, combined in weight ratios between 95/5 and 50/50, were subjected to reactive blending with different methods (single-screw extruder, Brabender, pyrex reactor). Pure Nylon samples have been also investigated as reference materials. The soluble Nylon 6,6-rich fraction of each blend was separated from the insoluble Vectra-rich one and used for molecular and spectroscopic characterisations. Thermal and morphological analyses, as well as testing of tensile properties, were carried out on the blends. Evidences of the occurrence of interchange reactions are given and the most probable ones are suggested. (C) 2001 Elsevier Science Ltd. All rights reserved.

Luminescence enhancement by blending PVK with blue PPV copolymer

The PL and EL properties of the polymer blends of PVK and blue PPV copolymer were studied. Considerable enhancement of both the photoluminescent and the electroluminescent intensity were observed by using the polymer blends as emission layer in the LED devices. The energy transfer process and the formation of exciplex in the polymer blends were also discussed.

Conductive polyaniline poly-omega-aminoundecanoyle blending fiber

Conductive fibers were obtained by blending polyaniline with poly-omega-aminoundecanoyle in-concentrated H2SO4 Micro-fiber caused by non-compatibility between the two polymers was valuable for improving conductive property of the fibers. Abnormal effect on the crystallinity of polyaniline and poly-omega-aminoundecanoyle upon drawing stress was observed.

Enhanced glass fiber-reinforced phenolphthalein poly(ether ketone) composites by blending poly(phenylene sulfide)

The mechanical properties of glass fiber-reinforced phenolphthalein poly(ether ketone)/poly(phenylene sulfide) (PEK-C/PPS) composites have been studied. The morphologies of fracture surfaces were observed by scanning electron microscope. Blending a semicrystalline component, PPS, can improve markedly the mechanical properties of glass fiber-reinforced PEK-C composites. These results can be attributed to the improvement of fiber/matrix interfacial adhesion and higher fiber aspect ratio. (C) 1996 John Wiley & Sons, Inc.

SketchIT: A Sketch Interpretation Tool for Conceptual Mechanical Design

We describe a program called SketchIT capable of producing multiple families of designs from a single sketch. The program is given a rough sketch (drawn using line segments for part faces and icons for springs and kinematic joints) and a description of the desired behavior. The sketch is "rough" in the sense that taken literally, it may not work. From this single, perhaps flawed sketch and the behavior description, the program produces an entire family of working designs. The program also produces design variants, each of which is itself a family of designs. SketchIT represents each family of designs with a "behavior ensuring parametric model" (BEP-Model), a parametric model augmented with a set of constraints that ensure the geometry provides the desired behavior. The construction of the BEP-Model from the sketch and behavior description is the primary task and source of difficulty in this undertaking. SketchIT begins by abstracting the sketch to produce a qualitative configuration space (qc-space) which it then uses as its primary representation of behavior. SketchIT modifies this initial qc-space until qualitative simulation verifies that it produces the desired behavior. SketchIT's task is then to find geometries that implement this qc-space. It does this using a library of qc-space fragments. Each fragment is a piece of parametric geometry with a set of constraints that ensure the geometry implements a specific kind of boundary (qcs-curve) in qc-space. SketchIT assembles the fragments to produce the BEP-Model. SketchIT produces design variants by mapping the qc-space to multiple implementations, and by transforming rotating parts to translating parts and vice versa.

The Sales Process Practice of Food and Drink SMEs - A Holistic Conceptual Framework: Steps, dimensions, barriers and enablers.

Purpose –The research examines the sales process practised by SMEs, and barriers and enablers that hinder and support effective selling practices from the selling organisation’s perspective in Scottish-based Food and Drink firms. Design/methodology approach - – The paper adopts an interpretivist perspective with qualitative data gathered through face-to-face semi-structured interviews. 20 people involved in selling activities were interviewed from 15 SMEs across Scotland. Thematic analysis established key findings regarding the sales process practice. Findings – Five themes emerged that affect the operationalisation of the selling process: the owner manager has considerable involvement in the sales process, SMEs with some degree of sales knowledge take a more systematic approach, SMEs lack awareness of how CRM technology can assist them, power is tipped in favour of the buyer and, the geographic location of the SME places constraints on how SMEs conduct business Research limitation/implication – Thematic analysis was chosen over other more traditional methods due to the lack of relevant quantitative data. The phenomenon of the research and research methodology means that it will not be possible to repeat this study and replicate its findings. However, the process that has been adopted does provide a basis for future research. Originality/value - The paper identifies areas where future research is required in the field alongside suggestions where policy makers and government business agencies might focus intervention to assist SMEs improve delivery of the sales process and selling effectiveness

A framework for the transformation of the creative industries in a digital age.

The creative industries sector faces a constantly changing context characterised by the speed of the development and deployment of digital information systems and Information Communications Technologies (ICT) on a global scale. This continuous digital disruption has had significant impact on the whole value chain of the sector: creation and production; discovery and distribution; and consumption of cultural goods and services. As a result, creative enterprises must evolve business and operational models and practices to be sustainable. Enterprises of all scales, type, and operational model are affected, and all sectors face ongoing digital disruption. Management consultancy practitioners and business strategy academics have called for new strategy development frameworks and toolkits, fit for a continuously changing world. This thesis investigates a novel approach to organisational change appropriate to the digital age, in the context of the creative sector in Scotland. A set of concepts, methods, tools, and processes to generate theoretical learning and practical knowing was created to support enterprises to digitally adapt through undertaking journeys of change and organisational development. The framework is called The AmbITion Approach. It was developed by blending participatory action research (PAR) methods and modern management consultancy, design, and creative practices. Empirical work also introduced to the framework Coghlan and Rashford’s change categories. These enabled the definition and description of the extent to which organisations developed: whether they experienced first order (change), second order (adaptation) or third order (transformation) change. Digital research tools for inquiry were tested by a pilot study, and then embedded in a longitudinal study over two years of twentyone participant organisations from Scotland’s creative sector. The author applied and investigated the novel approach in a national digital development programme for Scotland’s creative industries. The programme was designed and delivered by the author and ran nationally between 2012-14. Detailed grounded thematic analysis of the data corpus was undertaken, along with analysis of rich media case studies produced by the organisations about their change journeys. The results of studies on participants, and validation criteria applied to the results, demonstrated that the framework triggers second (adaptation) and third order change (transformation) in creative industry enterprises. The AmbITion Approach framework is suitable for the continuing landscape of digital disruption within the creative sector. The thesis contributes to practice the concepts, methods, tools, and processes of The AmbITion Approach, which have been empirically tested in the field, and validated as a new framework for business transformation in a digital age. The thesis contributes to knowledge a theoretical and conceptual framework with a specific set of constructs and criteria that define first, second, and third order change in creative enterprises, and a robust research and action framework for the analysis of the quality, validity and change achieved by action research based development programmes. The thesis additionally contributes to the practice of research, adding to our understanding of the value of PAR and design thinking approaches and creative practices as methods for change.

Appreciating ecological complexity: Habitat contours as a conceptual landscape model

Joern Fischer, David B. Lindermayer, and Ioan Fazey (2004). Appreciating Ecological Complexity: Habitat Contours as a Conceptual Landscape Model. Conservation Biology, 18 (5)pp.1245-1253 RAE2008

Radium and barium removal through blending hydraulic fracturing fluids with acid mine drainage.

Wastewaters generated during hydraulic fracturing of the Marcellus Shale typically contain high concentrations of salts, naturally occurring radioactive material (NORM), and metals, such as barium, that pose environmental and public health risks upon inadequate treatment and disposal. In addition, fresh water scarcity in dry regions or during periods of drought could limit shale gas development. This paper explores the possibility of using alternative water sources and their impact on NORM levels through blending acid mine drainage (AMD) effluent with recycled hydraulic fracturing flowback fluids (HFFFs). We conducted a series of laboratory experiments in which the chemistry and NORM of different mix proportions of AMD and HFFF were examined after reacting for 48 h. The experimental data combined with geochemical modeling and X-ray diffraction analysis suggest that several ions, including sulfate, iron, barium, strontium, and a large portion of radium (60-100%), precipitated into newly formed solids composed mainly of Sr barite within the first ∼ 10 h of mixing. The results imply that blending AMD and HFFF could be an effective management practice for both remediation of the high NORM in the Marcellus HFFF wastewater and beneficial utilization of AMD that is currently contaminating waterways in northeastern U.S.A.

Análisis de una propuesta de evaluación en relación con la estructura conceptual de la proporcionalidad

La presente propuesta es una aproximación reflexiva y critica de las prácticas evaluativas que se vienen desarrollando en la enseñanza básica y media en las instituciones de carácter privado de la ciudad de Cali, sustentada desde nuestra propia experiencia como docentes en ejercicio y estudiantes de último semestre en Licenciatura de Matemáticas y Física de la Universidad del Valle, y apoyada en el análisis de unas actividades piloto de intervención y evaluación matemática, en torno a diferentes nociones y conceptos relacionados con la estructura conceptual del tópico de proporción y proporcionalidad en los grados de séptimo de educación básica y décimo de educación media que se realizaron a fin de plantear una serie de interrogantes cruciales en torno a la evaluación, dado su carácter organizador, dinamizador y potencializador del currículo. Esta propuesta se apoyará en el marco metodológico de los organizadores del currículo, donde la evaluación es un eje fundamental en el análisis didáctico que permite la articulación y organización de un currículo significativo para los intereses de los educandos.

Herramientas para el fortalecimiento conceptual en el desarrollo de las competencias matemáticas (IAP)

Se presenta una propuesta desarrollada en el Departamento del Magdalena, Distrito Cultural e Histórico de Santa Marta. A finales del año 2002 se hizo un análisis de los bajos resultados presentados por los estudiantes de grado Once en las diferentes pruebas aplicadas por el ICFES, específicamente en el área de Matemática durante los años 2001 y 2002. A partir de estos resultados se organizó un equipo de trabajo donde se asumió que la evaluación es un proceso continuo e integral en la enseñanza de la matemática que no solo basta dar información a diario, sino conocer realmente si los estudiantes están aprendiendo, si verdaderamente los alumnos son competentes a la hora de evaluarlos y además si se cumplen los estándares mínimos exigidos por MEN. Para lograr tal fin se diseño un plan estratégico a mediano plazo que ayuda a fortalecer los niveles de desempeño en el desarrollo de sus competencias tanto integrales ((interpretativa, argumentativa, propositiva) como básicas (la comunicación, el razonamiento y la solución de problemas), obteniéndose a partir del año 2006 resultados satisfactorios en el área.

Desarrollo del conocimiento didáctico de los futuros profesores de matemáticas: el caso de la estructura conceptual y los sistemas de representación

Presentamos los primeros resultados de un estudio exploratorio sobre el desarrollo del conocimiento didáctico de futuros profesores de matemáticas con respecto a las nociones de estructura conceptual y sistemas de representación. Estos resultados se obtuvieron al codificar y analizar las grabaciones de clase y las producciones de estudiantes del último curso de Matemáticas en una asignatura de didáctica de las matemáticas. Se encontró que las producciones y las actuaciones de los alumnos pasan por diferentes estados que permiten identificar tanto algunas dificultades, como momentos en los que surgen reorganizaciones conceptuales.

Razonamiento covariacional aplicado a la modelación de eventos dinámicos: un marco conceptual y un estudio

Se desarrolla la noción de razonamiento covariacional y se propone un marco conceptual para describir las acciones mentales involucradas al aplicar razonamiento covariacional cuando se interpretan y representan funciones asociadas a eventos dinámicos. Se reporta la habilidad para razonar sobre cantidades covariantes en situaciones dinámicas, de estudiantes de alto desempeño en un curso de cálculo. El estudio reveló que ellos eran capaces de construir imágenes de la variable dependiente de una función que cambia simultáneamente con el cambio imaginado de la variable independiente, y en algunas ocasiones eran capaces de construir imágenes de la razón de cambio para intervalos contiguos del dominio de una función. Sin embargo, al parecer, tuvieron dificultad para formar imágenes de una razón cambiante de manera continua y no pudieron representar con exactitud o interpretar los puntos de inflexión ni la razón creciente y decreciente para funciones asociadas a situaciones dinámicas. Estos hallazgos sugieren que el currículo y la instrucción deberían aumentar el énfasis en el cambio que debe darse en los alumnos de una imagen coordinada de dos variables que cambian simultáneamente a una imagen coordinada de razón de cambio instantánea con cambios continuos en la variable independiente para funciones asociadas a situaciones dinámicas.