894 resultados para Process of conversion


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This work reports the energy transfer mechanism process of [Eu(TTA)(2)(NO(3))(TPPO)(2)] (bis-TTA complex) and [Eu(TTA)(3)(TPPO)(2)] (tris-TTA complex) based on experimental and theoretical spectroscopic properties, where TTA = 2-thienoyltrifluoroacetone and TPPO = triphenylphosphine oxide. These complexes were synthesized and characterized by elemental analyses, infrared spectroscopy and thermogavimetric analysis. The theoretical complexes geometry data by using Sparkle model for the calculation of lanthanide complexes (SMLC) is in agreement with the crystalline structure determined by single-crystal X-ray diffraction analysis. The emission spectra for [Gd(TTA)(3)(TPPO)(2)] and [Gd(TTA)(2) (NO(3))(TPPO)(2)] complexes are associated to T -> S(0) transitions centered on coordinated TTA ligands. Experimental luminescent properties of the bis-TTA complex have been quantified through emission intensity parameters Omega(lambda)(lambda = 2 and 4), spontaneous emission rates (A(rad)), luminescence lifetime (tau), emission quantum efficiency (eta) and emission quantum yield (q), which were compared with those for tris-TTA complex. The experimental data showed that the intensity parameter value for bis-TTA complex is twice smaller than the one for tris-TTA complex, indicating the less polarizable chemical environment in the system containing nitrate ion. A good agreement between the theoretical and experimental quantum yields for both Eu(Ill) complexes was obtained. The triboluminescence (TL) of the [Eu(TTA)(2)(NO(3))(TPPO)(2)] complexes are discussed in terms of ligand-to-metal energy transfer. (c) 2007 Elsevier B.V. All fights reserved.

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'Building bridges' is a metaphor we have used to describe a collaborative research process involving social work academic and senior practitioners from government and non-government child protection and family service organizations in Victoria, Australia. The purpose of the research was to develop a 'practice-generated approach to policy implementation' in child protection practice. The research sought to explore the appropriateness of social constructionist approaches for child protection practice that might enhance the existing risk paradigm. This article aims to critically evaluate the process of 'building bridges' and its outcomes, by focusing on how potential and actual differences between organizational contexts, namely universities and various serviceproviding organizations, may influence relationships between theory and practice. We critically reflect on our research process comparing it with idealized forms of collaborative research discussed in the literature.

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Thermosetting polymer blends of poly(ethylene oxide) (PEO) and bisphenol-A-type epoxy resin (ER) were prepared using 4,4′-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA) as curing agent. The miscibility and crystallization behavior of MCDEA-cured ER/PEO blends were investigated by differential scanning calorimetry (DSC). The existence of a single composition-dependent glass transition temperature (Tg) indicates that PEO is completely miscible with MCDEA-cured ER in the melt and in the amorphous state over the entire composition range. Fourier-transform infrared (FTIR) investigations indicated hydrogen-bonding interaction between the hydroxyl groups of MCDEA-cured ER and the ether oxygens of PEO in the blends, which is an important driving force for the miscibility of the blends. The average strength of the hydrogen bond in the cured ER/PEO blends is higher than in the pure MCDEA-cured ER. Crystallization kinetics of PEO from the melt is strongly influenced by the blend composition and the crystallization temperature. At high conversion, the time dependence of the relative degree of crystallinity deviated from the Avrami equation. The addition of a non-crystallizable ER component into PEO causes a depression of both the overall crystallization rate and the melting temperature. The surface free energy of folding σe displays a minimum with variation of composition. The spherulitic morphology of PEO in the ER/PEO blends exhibits typical characteristics of miscible crystalline/amorphous blends, and the PEO spherulites in the blends are always completely volume-filling. Real-time small-angle X-ray scattering (SAXS) experiments reveal that the long period L increases drastically with increasing ER content at the same temperatures. The amorphous cured ER component segregates interlamellarly during the crystallization process of PEO because of the low chain mobility of the cured ER. A model describing the semicrystalline morphology of MCDEA-cured ER/PEO blends is proposed based on the SAXS results. The semicrystalline morphology is a stack of crystalline lamellae; the amorphous fraction of PEO, the branched ER chains and imperfect ER network are located between PEO lamellae.

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We have combined high-performance liquid chromatography (HPLC) separations using a monolithic column with acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence detection in a rapid and highly sensitive method to monitor the process of extracting opiate alkaloids from Papaver somniferum. Due to the high flow rates allowed with the monolithic column and the inherent selectivity of the chemiluminescence reactions, the four predominant alkaloids – morphine, codeine, oripavine and thebaine – were determined in less than 2 min. The results obtained with numerous process samples compared favourable with those of the standard HPLC methodology. Limits of detection were 1 × 10−10 M, 5 × 10−10 M, 5 × 10−10 M and 1 × 10−9 M, for morphine, codeine, oripavine and thebaine, respectively.

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This article reviews the precautionary principle as an approach in addressing decisions with far reaching environmental consequences under scientific uncertainty. The precautionary principle is intended to assist with structuring environmentally risky decisions toward sustainable development. It responds to the lack of scientific evidence of a potential environmental problem. There is currently no framework to assist with the process indicating the areas of importance and stages of decisionmaking. This paper suggests a framework to assist with the process of decision-making for complex environmental problems. The main areas of concern are the issues relating to the costs, risks, and benefits assessments. The main stages of the framework includes; definition of the problem, analysis of the potential environmental risks, assessments of specific anticipated legal, social, economic, political, and technological impacts, review of the key players (social, organisation and government) obligations, comparison of alternatives available, determination of accountability, implementation, decision making, monitoring and control processes.

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This paper is concerned with how employees talk about their experiences of organizational change and focuses specifically on the construction of conversion stories. These are particularly positive narratives that consider change as a turning point in which individuals depart from an old way of life pre-change to embrace a post-change organization. In this study, employees seek conversion into management groups and report the values and philosophies of management in their narratives, thus highlighting the benefits of change while suppressing any negative aspects. This paper draws attention to the dramatic nature of the conversion story and explores the sharp distinction between the reporting of experiences prior to and after change. We also investigate the relationship between constructing conversion stories and gaining personal and career advancement at work and suggest that beneath the positive exterior of the conversion narratives lies a theme of silence, which may be related to career advancement. Our findings suggest that such stories of silence complicate the conversion story as an example of positive organizational change and discuss implications for both the theory and practice of narrative change research.

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This paper presents the results of a qualitative study conducted in Quebec, Canada, with occupational therapists working in mental health. Data were gathered through self-reported narratives of four occupational therapists over the 2 years it took to implement the Remotivation Process (de las Heras, Llerena, & Kielhofner, 2003) and develop a research protocol. Through the descriptive analysis of their narratives, the positive changes this intervention approach had on clients and on occupational therapy practice are highlighted. The experience of the therapists in developing a research protocol is addressed. Finally, the research protocol evaluating the effect of the Remotivation Process on the recovery process of people with depression is presented.

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A process for the production of ultrafine powders consisting of individual particles with sizes in the range of 1 nm to 200 nm, which is based on the mechanical milling of two or more non-reacting powders. The process includes subjecting a suitable precursor metal compound and a non-reactant diluent phased to mechanical milling which through the process of mechanical activation reduces the microstructure of the mixture of the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. Heat treating the milled powder converts the nano-sized grains of the precursor metal compound into a desired metal oxide phase. Alternatively, the precursor metal compound may itself be an oxide phase which has the requisite milling properties to form nanograins when milled with a diluent. An ultrafine powder is produced by removing the diluent phase such that nano-sized grains of the desired metal oxide phase are left behind. The process facilitates a significant degree of control over the particle size and size distribution of the particles in the ultrafine powder by controlling the parameters of mechanical activation and heat treatment.

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In this paper, we discuss a special case of knowledge creation via pattern mining that was studied using a hermeneutic approach. The reported study explores the nature of knowledge creation by domain practitioners who do not communicate directly. The focus of this paper extends the traditional view of a knowledge creation process beyond organisational boundaries. The proposed knowledge creation framework explains the facilitated process of knowledge creation by its qualification, combination, socialisation, externalisation, internalisation and introspection, thus allowing the transformation of individual experience and knowledge into formalised shareable domain knowledge.

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This research investigates effectiveness of real site visits within an undergraduate course. Experiential learning is a process of providing education, based on the experiences and observations of real-world examples. Some of the theory of experiential learning has been used to examine whether site visits assist the students learning experience.

The results of the research show that students generally have a positive attitude towards site visits and see them as beneficial. Although the study identified that some aspects of construction technology could be easily replaced by computer simulations and the like, other aspects of the curriculum are more effectively taught by retaining real site visits. The research was intended to provide a more structured approach to determining the value of site-based learning in construction-related courses.

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In 1860 Florence Nightingale conducted a study on the mortality rates of indigenous children attending native colonial schools across the British Empire. Her study was driven by the question: ‘Can we civilise the natives without killing them?’ One colonial school that participated in the survey was New Norcia Benedictine mission in Western Australia. When Rosendo Salvado, the mission’s superintendent, responded, he drew on his daily encounters with the Yuat people, his statistics on the mission residents and his Benedictine philosophy of civilisation and conversion of colonised peoples. The correspondence between Salvado and Nightingale took place in the climate of intense debates about Aboriginal health, colonisation and extinction in Britain and the colonies. While many settlers and colonial observers understood Aboriginal depopulation to be the result of either the vices and diseases of unprincipled Europeans or an unstoppable destiny, whether Divine Providence or natural selection, Nightingale and Salvado shared a belief in practical solutions to what they understood to be a practical problem. Their collaboration is an example of the humanitarian opposition to the racial pessimism of Social Darwinism. They both sought to use the recently influential intellectual discipline of social statistics to support their conviction that Aborigines, if patiently and carefully handled, would survive the admittedly risky process of civilisation.

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Shape conversions of silver nanoplates were realized by heating and subsequent light irradiation. The initial silver nanoprisms were transformed into silver nanodisks gradually in the process of heating, which was possibly achieved through dissolving and readsorption of silver atoms on the surface of silver nanoplates. Subsequently, under light irradiation, the heating induced silver nanodisks were reversed to silver nanoprisms in the same solution. The dissolved oxygen was found to play a pivotal role in the shape conversion from nanoprism to nanodisk. In addition to heating, deionized water could induce the shape conversion of silver nanoplates when it was added to precipitate of the initial silver nanoprisms after centrifugation. Citrate in solution is essential to the photoinduced shape conversion process. Transmission electron microscopy (TEM) and extinction spectroscopy results demonstrated that localized surface plasmon resonance (LSPR) properties of silver nanoplates were effectively tuned through shape conversion.

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Service companies possess different characteristics from non-service-based companies, affecting their process of internationalization. This article examines the internationalization of service organizations using case studies of 23 Australian service organizations internationalizing to China. It finds that the internationalization process is influenced by the type of service the organization produces. The Uppsala internationalization model partially explains internationalization for companies producing exportable services but did not explain internationalization for companies, which produce nonexportable services (services that must be located within the market). International experience, government regulations and capital intensity were influential for internationalization. The findings develop a model for service organization internationalization.

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The present work aims at finding a relationship between kinetic models of thermal degradation process with the physiochemical structure of epoxy-clay nanocomposites in order to understand its service temperature. In this work, two different types of modified clays, including clay modified with (3-aminopropyl)triethoxysilane (APTES) and a commercial organoclay, were covalently and non-covalently incorporated into epoxy matrix, respectively. The effect of different concentrations of silanized clay on thermal behaviour of epoxy nanocomposites were first investigated in order to choose the optimum clay concentration. Afterwards, thermal characteristics of the degradation process of epoxy nanocomposites were obtained by TGA analysis and the results were employed to determine the kinetic parameters using model-free isoconversional and model-fitting methods. The obtained kinetic parameters were used to model the entire degradation process. The results showed that the incorporation of the different modified clay into epoxy matrix change the mathematical model of the degradation process, associating with different orientations of clay into epoxy matrix confirming by XRD results. The obtained models for each epoxy nanocomposite systems were used to investigate the dependence of degradation rate and degradation time on temperature and conversion degree. Our results provide an explanation as to how the life time of epoxy and its nanocomposites change in a wide range of operating temperatures as a result of their structural changes.

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Purpose – This paper aims to examine the elements of the main process of pilgrimage tourism (PT), occurring between pilgrims, hikers and tourists along a trail towards a holy site. PT is defined as a process consisting of three sub-processes over time and across contexts: pre-process, main process and post-process. Design/methodology/approach – Explores the core reasons for PT through active participation and observation. Findings – This study reveals different layers, levels, views, approaches and perspectives involved in people-based processes. The study attempts to conceptualize the elements involved between people committed and dedicated to PT. Research limitations/implications – The introduced model of PT stresses the processes and interfaces involved over time and across contexts between people, with the same or different sequences. There is, to the best of the authors’ knowledge, no previous research that explores and describes the processes and interaction between pilgrims, hikers and tourists. Practical implications – The ultimate experience at an individual level differs, depending upon the outcome of the PT-elements of the model of PT (i.e. processes, interfaces, people and sequences). Social implications – From a social science perspective, the research examines the motives of different traveller types and looks at their different perspectives of being involved with the same physical activity of travel. The study emphasises that we can be involved in the same physical activity, but embrace it with different levels of personal and emotional engagement. Originality/value – A conceptualized model of PT containing four elements (process, interface, people and sequence) – all of which offer a foundation for structuring and assessing empirical research, and provide additional insights and knowledge into the dynamics and complexity involved specifically in a people-based process consisting of interfaces and sequences when travelling.