Frameworks

Distribution by Scientific Domains
Distribution within Humanities and Social Sciences

Kinds of Frameworks

  • analytical frameworks
  • conceptual frameworks
  • coordination frameworks
  • different frameworks
  • explanatory frameworks
  • host frameworks
  • institutional frameworks
  • legal frameworks
  • metal-organic frameworks
  • national qualification frameworks
  • national service frameworks
  • organic frameworks
  • policy frameworks
  • qualification frameworks
  • regulatory frameworks
  • service frameworks
  • supramolecular frameworks
  • temporal frameworks
  • theoretical frameworks
  • three-dimensional frameworks
  • various frameworks


  • Selected Abstracts


    Influence of Semi-Rigid Connections and Local Joint Damage on Progressive Collapse of Steel Frameworks

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2010
    Yuxin Liu
    This article extends the threat-independent method for progressive-failure analysis of rigid frames to analysis accounting for semi-rigid connections. The influence of joint damage caused by disengagement of member(s) is also considered in the analysis, and the degree of damage is modeled by a health index. A compound element model is employed to include the contributions of nonlinear behavior of beam-to-column connections, connection and member-end damage, member inelasticity, member shear deformation, and geometrical nonlinearity to structural response. Four beam collapse modes are illustrated for the progressive collapse analysis associated with debris loading generated when disengaged structural components fall onto lower parts of the structure. The impact effect is taken into account for the quasi-static nonlinear analysis by utilizing an impact amplification factor according to GSA and DoD guidelines. Any progressive collapse occurring thereafter involves a series of collapse events associated with topological changes of the frame. The analysis procedure is illustrated for the progressive collapse behavior of two planar steel frames. The results demonstrate that the proposed method is potentially an effective tool for the progressive collapse analysis of semi-rigid steel frames under abnormal loading events. [source]


    The Cartagena Protocol: Implications for Regional Trade and Technology Development in Africa

    DEVELOPMENT POLICY REVIEW, Issue 1 2008
    E. Jane Morris
    The majority of African countries have ratified or acceded to the Cartagena Protocol on Biosafety, and many have received support through the Global Environment Facility and the UN Environment Programme for development of their National Biosafety Frameworks. This article examines the extent to which these frameworks are aligned with the goals of the Regional Economic and Regional Research Communities of which they are members. Many national approaches lack alignment with regional trade, economic, science and technology policies. The strict application of the precautionary principle and the imposition of costly administrative hurdles are likely to hinder intra-regional trade and technology development. [source]


    The implementation of nutritional advice for people with diabetes

    DIABETIC MEDICINE, Issue 10 2003
    Nutrition Subcommittee of the Diabetes Care Advisory Committee of Diabetes UK
    Abstract These consensus-based recommendations emphasize the practical implementation of nutritional advice for people with diabetes, and describe the provision of services required to provide the information. Important changes from previous recommendations include greater flexibility in the proportions of energy derived from carbohydrate and monounsaturated fat, further liberalization in the consumption of sucrose, more active promotion of foods with a low glycaemic index, and greater emphasis on the provision of nutritional advice in the context of wider lifestyle changes, particularly physical activity. Monounsaturated fats are now promoted as the main source of dietary fat because of their lower susceptibility to lipid peroxidation and consequent lower atherogenic potential. Consumption of sucrose for patients who are not overweight can be increased up to 10% of daily energy derived from carbohydrate provided that this is eaten in the context of a healthy diet and distributed throughout the day. Evidence is presented for the effectiveness of advice provided by trained dieticians. The increasing evidence for the importance of good metabolic control and the growing requirement for measures to prevent Type 2 diabetes in an increasingly obese population will require major expansion of dietetic services if the standards in National Service Frameworks are to be successfully implemented. [source]


    Food Security in Protracted Crises: Building More Effective Policy Frameworks

    DISASTERS, Issue 2005
    Margarita Flores
    This paper considers the principal elements that underpin policy frameworks for supporting food security in protracted crisis contexts. It argues that maintaining the food entitlements of crisis-affected populations must extend beyond interventions to ensure immediate human survival. A ,policy gap' exists in that capacities for formulating policy responses to tackle the different dimensions of food insecurity in complex, fluid crisis situations tend to be weak. As a result, standardised, short-term intervention designs are created that fall short of meeting the priority needs of affected populations in the short and long term and only partially exploit the range of policy options available. The paper discusses key attributes of agency frameworks that could support more effective policy processes to address longer term as well as immediate food security needs. Additionally, it points to some main challenges likely to be encountered in developing such frameworks and, with the participation of beneficiaries, translating them into effective action. [source]


    Frameworks for Language Study at A Level

    ENGLISH IN EDUCATION, Issue 2 2000
    John Keen
    Abstract This article argues that students of language study at A level need opportunities to build a broad foundation for exploring language experience, familiar issues and accessible concepts using practical activities and informal discussion if they are to develop their understanding of the more formal and systematic aspects of language theory. Teachers need familiarity with the staging points which correspond to different levels of students' understanding, and access to frameworks for language study which are sufficiently detailed to enable them to recognise growth points and build on students' achievements. [source]


    Recent developments in frameworks to consider human relevance of hypothesized modes of action for tumours in animals,

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2008
    M.E. Bette Meek
    Abstract This paper summarizes recent developments in the continuing evolution of Human Relevance Frameworks to systematically consider the weight of evidence of hypothesized modes of action in animals and their potential human relevance for both cancer and non-cancer effects. These frameworks have been developed in initiatives of the International Life Sciences Institute Risk Sciences Institute and the International Programme on Chemical Safety engaging large numbers of scientists internationally. They are analytical tools designed to organize information in hazard characterization as a basis to clarify the extent of the weight of evidence for mode of action in animals and human relevance and subsequent implications for dose-response. They are also extremely helpful in identifying critical data gaps. These frameworks which are illustrated by an increasing number of case studies, have been widely adopted into international and national guidance and assessments and continue to evolve, as experience increases in their application. Environ. Mol. Mutagen., 2008. Published 2008 Wiley-Liss, Inc. [source]


    National Qualification Frameworks: from policy borrowing to policy learning

    EUROPEAN JOURNAL OF EDUCATION, Issue 2 2010
    BORHENE CHAKROUN
    This article takes up the issue of the internationalisation of Vocational Education and Training (VET) reforms, expressed in the way policy instruments such as National Qualifications Frameworks (NQF) are introduced in the European Training Foundation's (ETF) partner countries. There is an international debate and different perspectives regarding NQFs. These perspectives have largely talked past each other. The article brings together these perspectives and highlights the issues at stake in this field. Through the analysis of ETF interventions in different regions, the article makes a case for new approaches of intervention, namely policy learning, that aim at enabling national stakeholders and that are conducive for home-grown VET policies. The discussion is broad in scope, not only because the article reviews developments in qualifications frameworks across-regions, but also because it highlights the complex interaction of the global and local development when introducing NQFs and the impact of such reforms on VET systems. [source]


    Qualifications Frameworks: some conceptual issues

    EUROPEAN JOURNAL OF EDUCATION, Issue 4 2007
    MICHAEL YOUNG
    The aim of this article is to contribute to realising the progressive and democratic opportunities that National Qualifications Frameworks (NQFs) can offer. In doing so it will be critical of many of the ways that NQFs have been interpreted to date and the claims that have been made for them. The article has six sections. Section 1 considers some of the reasons for the recent growth of interest in NQFs. Section 2 is concerned with the widely shared goals of NQFs and some of the contradictions and problems that they involve. Section 3 discusses the very different forms that NQFs can take. Section 4 examines a number of issues that underlie all approaches to qualifications but are made more explicit by qualification frameworks and concludes by questioning the much lauded claim that NQFs can promote and accredit informal learning. The concluding section considers the longer term implications for the future of NQFs of the earlier analysis. [source]


    Frameworks by Solvent-Free Synthesis of Rare Earth Chlorides with Molten 1,3-Benzodinitrile and Tailoring of the Particle Size: ,3[LnCl3{1,3-C6H4(CN)2}], Ln = Y, Dy, Ho, Er, Yb

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2010
    Christoph J. Hller
    Abstract The solvent-free melt reactions of anhydrous rare earth trichlorides with molten 1,3-benzodinitrile [1,3-C6H4(CN)2, C8H4N2] result in isophthalonitrile frameworks of the rare earth elements. The particle size of the products can bevaried from the millimeter to the nanometer scale (down to 50,400 nm) depending on the synthesis conditions. Thus, these network structures are among the very few coordination polymers that can be synthesized as nanoparticles. A constitution of 1:1 concerning LnCl3/1,3-C6H4(CN)2 is found for Y (1), Dy (2), Ho (3), Er (4), and Yb (5) in isotypic,3[LnCl3{1,3-C6H4(CN)2}]. The ligand 1,3-C6H4(CN)2 functions both as chemical scissors and replaces chloride linkages by degrading the rare earth chloride structures, and subsequently forms new 3D-framework structures. They consist of strands of chlorido-coordinated lanthanide atoms, which are linked in two dimensions by 1,3-C6H4(CN)2 molecules. Compounds 1,5 were obtained as single crystals from the melt reaction, and their crystal structures were determined by single-crystal X-ray analysis. They can also be obtained as nanocrystalline materials from a ball mill treatment, identified by electron microscopy (REM) and EDX analysis. [source]


    Synthesis and Structure Characterization of Copper Terephthalate Metal,Organic Frameworks

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2009
    Cantwell G. Carson
    Abstract In this paper, we report on a high-throughput (gram quantities) solvothermal method for the synthesis of copper terephthalate metal,organic frameworks in dmf. While the structure of MOF-2 and some of the associated polymorphs are well known, we know of no equivalent structural studies for the isostructural copper terephthalate (Cu,tpa). The material we have made crystallizes in the C2/m space group. Cu,tpa also exhibits reversible solvent-exchange properties. These properties make this material useful for potential applications in gas storage and catalysis applications. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Novel (3,4)- and (4,5)-Connected Lanthanide Metal,Organic Frameworks

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2008
    Xian-Wen Wang
    Abstract The three-dimensional lanthanide noninterpenetrating metal,organic frameworks formulated as [Ln(3,5-pdc)(C2O4)0.5(H2O)2]H2O (Ln = LuIII, GdIII, TmIII and YbIII for complex 1,4, respectively; 3,5-pdc = 3,5-pyridinedicarboxylate) were synthesized by hydrothermal reactions of 3,5-H2pdc with lanthanide oxide and perchloric acid. Compound 1 shows (3,4)-connected (4.82)(4.85) dmc-type topological network, and complexes 2,4 display the novel (4,5)-connected (44.6.8)(44.62.84) xww-type topology. The lanthanide-mediated transformation of CO2 to oxalate under hydrothermal conditions was observed. The fluorescence properties of complexes 1,4 were investigated. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


    Rarely Decorated Rutile Frameworks Built from Triangular Organic Spacers and Distorted Octahedral Co3 Building Blocks

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 24 2007
    Feng Luo
    Abstract Under mild temperatures, the self-assembly of CoCl2 and H3BTC in a solution of dmso generates a guest-free metal,organic polymer, namely Co3(BTC)2(,1 -dmso)2(,2 -dmso)2(1: dmso = dimethylsulfoxide, H3BTC = 1,3,5-benzenetricarboxylic acid). In 1, the CoII ions show the six-coordinate octahedral geometry completed by the BTC3, ions and the dmso oxygen atoms; remarkably, the coordinated dmso ligands not only act as terminal ligands to complete the octahedral geometry of the CoII ions, but also play an important role in bridging CoII ions together to give the Co3 secondary building units (SBUs). From a topological viewpoint, this novel polymer is classified to be the decorated (3,6)-connected rutile net with the (4.62)2(42.610.83) topology, where BTC3, ligands and Co3 SBUs are viewed to be the 3- and 6-connected nodes, respectively. In addition, the magnetic properties of 1 are explored by using a linear trinuclear cobalt mode, thusleading to g = 2.41, J = ,34.92 cm,1, TIP = 340,,10,6 cm3,mol,1,, = ,6 K (a , parameter was included to take into account intertrinuclear interactions).( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    Synthesis, Upconversion Luminescence and Magnetic Properties of New Lanthanide,Organic Frameworks with (43)2(46,66,83) Topology

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2007
    Danfeng Weng
    Abstract The synthesis and crystal structures of three new lanthanide,organic frameworks [Ln(pza)(OH)(H2O)]n (Ln = Y(1), Er(2), Yb(3); H2pza = 2,3-pyrazinedicarboxylic acid) with helical chains and novel 2D (43)2(46,66,83) topology are reported. The topology is obtained by simplifying the dinuclear metal core as a six-connected node and the ligand as a three-connected linker. The upconversion property measurement gives green and red emissions coming from two-photon excitation of Y: Er, Yb codoped coordination polymer and arising from ErIII transitions of 4S3/2/2H11/2,4I15/2 and 4F9/2,4I15/2. The magnetic properties of complexes 2 and 3 are also studied.( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    A Novel Copper(I) Halide Framework Templated by Organic,Inorganic Hybrid Polyoxometalate Chains Formed In Situ: A New Route for the Design and Synthesis of Porous Frameworks

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2006
    Hua Jin
    Abstract A 1D organic,inorganic hybrid polyoxometalate chain has been used as a non-coordinating anionic template for the construction of a novel 3D copper halide 4,4,-bipy framework, namely [Cu3ICl(4,4,-bipy)4][CuII(1,10-phen)2Mo8O26]. X-ray diffraction experiments revealed that the title compound consists of chloride-bridged trinuclear CuI units linked by neutral organic 4,4,-bipy groups into a 3D framework with hexagon-like channels in which 1D organic,inorganic hybrid polyoxometalate chains reside. This is the first example of a 1D organic,inorganic hybrid polyoxometalate chain functioning as a novel anionic template for the construction of a 3D framework. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    Hybrid 2D and 3D Frameworks Based on ,-Keggin Polyoxometallates: Experiment and Simulation

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2005
    Anne Dolbecq
    Abstract The ,-Keggin polyoxomolybdate {,-PMoV8MoVI4O40,x(OH)xM4} is a versatile building unit, with M being either a ZnII or a LaIII capping ion located at the vertices of a slightly distorted tetrahedron. The charge of the Keggin unit depends on the number of protonated oxo bridging ligands, which has been shown to vary from 0 to 5. The Keggin entity can thus be either an anion (M = Zn, x = 0) or a cation (M = La, x = 3,5). The Zn derivative has been generated in situ by hydrothermal synthesis and forms a 2D material built from the connection of the cations by 4,4'-bipyridine ligands linked to the capping ZnII ions. The reaction of the chloride salt of the La derivative with di-, tri- and tetrasubstituted benzenecarboxylate ligands has allowed us to isolate 2D and 3D materials. The 3D materials seem to be the first examples of hybrid open frameworks based on Keggin building blocks. The 3D framework built from the connection of ,-Keggin units by trimesate ions exhibits tunnels filled only by water molecules, which can be partly removed and reintroduced at room temperature. Besides these experimental results, simulation has allowed us to generate two virtual hybrid structures derived from those of known silicates by replacing the Si ions by hypothetical ,-Keggin cations and the O -bridging ligands by terephthalate ions, thus showing that 3D frameworks with large pores can be envisioned in the chemistry of hybrid organic,inorganic materials based on ,-Keggin units and motivating further experimental investigations. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]


    Three-Dimensional Lanthanoid-Containing Coordination Frameworks: Structure, Magnetic and Fluorescent Properties

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2005
    Hong-Tao Zhang
    Abstract Two lanthanoid-containing 3D coordination polymers, [Gd2L3(H2O)2]n (1) and {[TbL1.5(H2O)]0.5H2O}n (2) (L = succinate), have been prepared by hydrothermal reaction. The difference in structure between the two 3D coordination polymers is a result of the flexibility of the ligand conformation. The magnetic properties of 1 and 2 have been investigated in the 1.8,300 K range. Both complexes exhibit ferromagnetic interaction between lanthanoid ions. AC magnetic measurements revealed long-range magnetic order in complex 2. Especially 2 integrates the ferromagnetic, fluorescent and porous properties into a single entity. This motif may be developed to achieve new multifunctional molecular-based materials. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]


    Mechanism of Selective and Unselective Enclathration by a Host Compound Possessing Open, Flexible Host Frameworks

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2003
    Kazunori Nakano
    Abstract Molecular recognition of o -, m -, and p -xylenes (oX, mX, and pX) through enclathration of cholic acid (CA) is described. All of the xylenes give lattice inclusion crystals with CA, and crystallographic studies reveal that they are included in different open host frameworks. In particular, oX has two polymorphs, depending on the recrystallization temperatures. Competitive recrystallization from mixtures of xylenes resulted in selective enclathrations and the formation of racemic mixed crystals. In the presence of an equimolar amount of oX, CA selectively includes mX or pX in the host frameworks, which are identical to those obtained from the pure mX or pX, respectively. The low affinity of oX is explained in terms of a lower stability of CAoX than of the other two complexes, as judged from the low PCcavity, the volume ratio of the guest compound to the host cavity. Meanwhile, mixtures of mX and pX yield inclusion crystals that accommodate both of the guests. These have the same open host framework as obtained from pure mX, and the guest components are disordered statically in the host cavity. The ratios of the xylene mixtures in the single crystals are similar to those in the original recrystallization mixtures, and also in the bulk crystals, indicating that CA forms mixed crystals of mX and pX. This non-selectivity is attributed to the similar stabilities of CAmX and CApX, according to the moderate PCcavity. The inclusion behavior of CA from mixtures of xylenes is quite similar to chiral recognition by diastereomer-salt methods. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


    Houses, Flowers, and Frameworks: Cavell and Mulhall on the Moral of Skepticism

    EUROPEAN JOURNAL OF PHILOSOPHY, Issue 2 2002
    Edward Witherspoon
    First page of article [source]


    Highly Fluorescent Mesostructured Films that consist of Oligo(phenylenevinylene),Silica Hybrid Frameworks,

    ADVANCED FUNCTIONAL MATERIALS, Issue 22 2008
    Norihiro Mizoshita
    Abstract Highly fluorescent and visible-light-responsive mesostructured organosilica films are successfully obtained by acidic sol,gel polycondensation of oligo(phenylenevinylene) (OPV)-bridged organosilane and tetraethoxysilane precursors in the presence of a template surfactant. The OPV-bridged organosilane precursors with different lateral alkoxy substituents, hexyloxy and 2-ethylhexyloxy, and no substituent, are synthesized by Rh-catalyzed silylation of corresponding aromatic iodides. From the organosilane precursors, three kinds of mesostructured OPV,silica hybrid films are prepared by spin-casting using evaporation-induced self-assembly. UV-vis absorption and fluorescence behavior of the OPV,silica hybrid films show that the optical properties and intermolecular interactions of the OPV moieties embedded within the organosilica frameworks strongly depend on the lateral alkoxy substituents in the precursors. The hexyloxy and 2-ethylhexyloxy substituents prevent aggregation of the OPV units in the organosilica frameworks; this result leads to high fluorescence quantum yields of 0.48,0.61 and 0.63,0.66, respectively, while non-substitution leads to lower fluorescence quantum yields of 0.25,0.34. Fluorescence decay profiles of the organosilica hybrid films also confirm a suppression of the aggregation of OPV moieties by the lateral substituents. These mesostructured organosilica films with significant optical properties in the visible-light region are promising as a new class of phosphor materials. [source]


    Microporous Metal,Organic Frameworks with High Gas Sorption and Separation Capacity,

    ADVANCED FUNCTIONAL MATERIALS, Issue 8 2007
    Y. Lee
    Abstract The design, synthesis, and structural characterization of two microporous metal,organic framework structures, [M(bdc)(ted)0.5]2,DMF0.2,H2O (M,=,Zn (1), Cu (2); H2bdc,=,1,4-benzenedicarboxylic acid; ted,=,triethylenediamine; DMF: N,N -dimethylformamide) is reported. The pore characteristics and gas sorption properties of these compounds are investigated at cryogenic temperatures, room temperature, and higher temperatures by experimentally measuring argon, hydrogen, and selected hydrocarbon adsorption/desorption isotherms. These studies show that both compounds are highly porous with a pore volume of 0.65 (1) and 0.52,cm3,g,,1 (2). The amount of the hydrogen uptake, 2.1,wt,% (1) and 1.8,wt,% (2) at 77,K (1,atm; 1,atm,=,101,325,Pa), places them among the group of metal,organic frameworks (MOFs) having the highest H2 sorption capacity. [Zn(bdc)(ted)0.5]2,DMF0.2,H2O adsorbs a very large amount of hydrocarbons, including methanol, ethanol, dimethylether (DME), n -hexane, cyclohexane, and benzene, giving the highest sorption values among all metal,organic based porous materials reported to date. In addition, these materials hold great promise for gas separation. [source]


    Research and development at the health and social care interface in primary care: a scoping exercise in one National Health Service region

    HEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 6 2002
    Jo Cooke MA
    Abstract The present project aimed to identify research activity at the health and social care interface in primary care within one National Health Service region, and to determine levels of research capacity and support within social services. The study was commissioned by a primary care research network (PCRN) in order to assess opportunities to increase research capacity within social services. Data were collected in two phases from 61 managers, team leaders and senior practitioners in social care, and six public health representatives in health authorities, using telephone interviews and focus groups. The findings highlighted a lack of infrastructure and support for research and development in social care. However, many social care respondents wanted opportunities to develop research skills with healthcare colleagues. Despite poor support, many small-scale projects were described, and many respondents showed an enthusiasm for engaging with research. Methods in use included surveys, action research, needs analysis and evaluation of service developments. Many examples of user involvement were given. Interface projects were usually instigated by interagency forums and funded from multiple sources. Most project work was motivated by service improvement or development, rather than aiming to produce generalisable knowledge. Barriers to conducting research included lack of confidence, research skills and time, as well as workload demands, lack of cover to release staff for research and lack of supervision. Research was not seen as legitimate work in some social care environments or as part of a career path. Existing joint working initiatives (such as the National Service Frameworks) were highlighted as flashpoints for potential research and evaluation activity. The findings suggest clear opportunities for PCRNs to develop research capacity at the interface with social care; for example, by signposting available resources, providing training grants and secondments for social care staff, and supporting interagency networks with a focus on evaluation. In turn, experience in promoting user involvement in social services could add value to research expertise at the primary care,social care interface. [source]


    Assembly of Pure Silver-Tungsten-Oxide Frameworks from Nanostructured Solution Processable Clusters and Their Evolution into Materials with a Metallic Component

    ADVANCED MATERIALS, Issue 38 2010
    Thomas McGlone
    Silver-Tungsten-Oxide Frameworks: Isomerically pure forms of the unique isopolyoxotungstate system are incorporated into highly connected framework materials using Ag(I) as a linking unit. Thermal treatment of the materials leads to the formation of silver microparticles embedded in a tungsten oxide matrix. This novel synthetic approach promises to create a new class of nanostructured tungsten-silver-oxides with exciting physical properties, as well as exemplifies the potential for new frameworks based upon solution processable POM clusters. [source]


    Engineering Homochiral Metal-Organic Frameworks for Heterogeneous Asymmetric Catalysis and Enantioselective Separation

    ADVANCED MATERIALS, Issue 37 2010
    Yan Liu
    Abstract Owing to the potential applications in technological areas such as gas storage, catalysis, separation, sensing and nonlinear optics, tremendous efforts have been devoted to the development of porous metal-organic frameworks (MOFs) over the past ten years. Homochiral porous MOFs are particularly attractive candidates as heterogeneous asymmetric catalysts and enantioselective adsorbents and separators for production of optically active organic compounds due to the lack of homochiral inorganic porous materials such as zeolites. In this review, we summarize the recent research progress in homochiral MOF materials, including their synthetic strategy, distinctive structural features and latest advances in asymmetric heterogeneous catalysis and enantioselective separation. [source]


    Coordination Modulation Induced Synthesis of Nanoscale Eu1- xTbx -Metal-Organic Frameworks for Luminescent Thin Films

    ADVANCED MATERIALS, Issue 37 2010
    Hailing Guo
    Strategies for synthesizing of nanoscale single or bimetallic lanthanide metal-organic framework (MOF) materials and their transformation into Eu1- xTbx -MOF thin films are reported. The thin films prepared via spin coating deposition method are smooth, dense and mechanically stable. They also exhibit marked luminescent properties and efficient Tb3+ -to-Eu3+ energy transferability. [source]


    Hydrogen Storage in Metal,Organic Frameworks

    ADVANCED MATERIALS, Issue 20 2010
    Yun Hang Hu
    Abstract Metal,organic frameworks (MOFs) are highly attractive materials because of their ultra-high surface areas, simple preparation approaches, designable structures, and potential applications. In the past several years, MOFs have attracted worldwide attention in the area of hydrogen energy, particularly for hydrogen storage. In this review, the recent progress of hydrogen storage in MOFs is presented. The relationships between hydrogen capacities and structures of MOFs are evaluated, with emphasis on the roles of surface area and pore size. The interaction mechanism between H2 and MOFs is discussed. The challenges to obtain a high hydrogen capacity at ambient temperature are explored. [source]


    The Construction of Qualification Levels and Frameworks: Issues from Three UK Projects

    HIGHER EDUCATION QUARTERLY, Issue 4 2001
    Stan Lester
    The United Kingdom is gradually moving to develop national frameworks of qualifications, with the aim of identifying all publicly-funded qualifications according to level, focus and, where appropriate, size or credit volume. Existing frameworks designed for use in higher education and occupational contexts reflect assumptions concerning things such as the nature of knowledge, the academic or occupational context of the learner, and the nature of access and progression within education and training. These assumptions do not hold for the full spectrum of qualifications, and need to be challenged if a fully inclusive framework is to emerge that is coherent while supporting requisite variety. [source]


    Lost Opportunity: What a Credit Framework Would Have Added to the National Qualification Frameworks

    HIGHER EDUCATION QUARTERLY, Issue 3 2001
    David Gosling
    This paper outlines the recent work of the Southern England Consortium, SEEC, and the principles to which it is committed. It is argued that the failure of the Quality Assurance Agency (QAA) to grasp the nettle of credit in the recently published National Qualification Framework (NQF) is a blow, although not a fatal one, to the achievement of the objectives which SEEC is attempting to achieve on behalf of its member institutions. In particular, the opportunity to improve access, increase flexibility and support lifelong learning through the use of credit in the NQF has been lost. The value of the concept of level in a credit framework is defended and contrasted with the use of ,qualification level' in the NQF. [source]


    MOF,Graphite Oxide Composites: Combining the Uniqueness of Graphene Layers and Metal,Organic Frameworks

    ADVANCED MATERIALS, Issue 46 2009
    Camille Petit
    Nanocomposites containing graphite oxide (GO) and metal,organic frameworks (MOFs) are prepared. They have a well-defined structure, in which graphene layers from GO alternate with layers of MOF via linkages between epoxy groups from GO and zinc oxide from the MOF (see image). The enhanced porosity and dispersive forces of the composites compared to the precursors provide views for applications in gas adsorption. [source]


    Colloidal Route for Preparing Optical Thin Films of Nanoporous Metal,Organic Frameworks

    ADVANCED MATERIALS, Issue 19 2009
    Patricia Horcajada
    Colloids of a highly flexible porous metal-organic framework (MOF) have been prepared using nontoxic and easily removable solvents. Furthermore, a simple dip-coating method for the preparation of optical-quality thin films of the MOF has been developed. The homogeneous thin film exhibits reversible flexibility, as has been proven by environmental ellipsometry. [source]


    Designing Macroeconomic Frameworks: A Positive Analysis of Monetary and Fiscal Delegation,

    INTERNATIONAL FINANCE, Issue 1 2005
    Francesca Castellani
    This paper proposes a simple model illustrating the potential benefits of approaching the design of a macroeconomic framework conducive to low inflation in both its monetary and fiscal dimensions rather than relying exclusively on the merits of central bank independence and other monetary commitment devices such as currency boards or dollarization. The reason is that monetary delegation alone merely ,relocates' the time-inconsistency problem stemming from the government's incentive to address structural output shortfall with a macroeconomic stimulus. This paper also provides a new argument explaining why fiscal deficit rules may be less effective than instrument-specific rules. [source]