Search results for "FRAMEWORK"
showing 10 items of 942 documents
Bio-metal-organic frameworks for molecular recognition and sorbent extraction of hydrophilic vitamins followed by their determination using HPLC-UV
2020
A bio-metal-organic framework (bio-MOF) derived from the amino acid L-serine has been prepared in bulk form and evaluated as sorbent for the molecular recognition and extraction of B-vitamins. The functional pores of bio-MOF exhibit high amounts of hydroxyl groups jointly directing other supramolecular host-guest interactions thus providing the recognition of B-vitamins in fruit juices and energy drinks. Single-crystal X-ray diffraction studies reveal the specific B-vitamin binding sites and the existence of multiple hydrogen bonds between these target molecules and the framework. It offered unique snapshots to accomplish an efficient capture of these solutes in complex aqueous matrices. Fo…
Points of View and Relativism
2020
This chapter defines the central concept of this book, the point of view. The development of viewpoint relativism is largely based on this concept. A point of view is defined as choosing a certain aspect of its object to represent it. In principle, points of view are subjective and they are anchored to the internal cognitive models of a person. But points of view can also be objectified linguistically and brought out to be publicly examined. Points of view are not permanent, but can be changed and developed, and even exchanged in certain cases. Points of view are not true or untrue as such, but the maps that are acquired through their adoption are more or less true. We can compare objectifi…
River Contracts for Innovation in Territorial Governance
2016
Emerged in France in 1980s as agreements oriented to the requalification of rivers and lakes, river contracts represent an important outcome of the decentralization process, developed in Europe in reply to the growing institutional fragmentation. In this scenario, rivers have become a dialectic arena in which the exploitation and management of water resources came to terms with environmental instances, and offered the breeding ground for concerted efforts between policy makers, stakeholders and communities. In this chapter, the analysis is focused on the river contract model and the related set of instruments capable of supporting concerted and participatory management processes both with r…
Design and Style of Cultural and Media Studies Textbooks for College Students
2014
This paper uses the conceptual framework of multimodal discourse analysis in order to investigate the dominant styles and designs in selected Cultural and Media Studies (CMS) university textbooks. For many EFL students who major in philology, CMS courses are obligatory and thus constitute a type of content and language integrated learning (CLIL). The data from a description and evaluation of four popular textbooks indicate that there is a discernible move away from traditional literacy towards visuality and orality in textbook design and style. This tendency is evident in the use of segmentation and listing in composition, dialogic layouts and informal registers in exposition and visual aid…
New zeolite-like RUB-5 and its related hydrous layer silicate RUB-6 structurally characterized by electron microscopy.
2020
RUB-5 and its related hydrous layer silicate RUB-6 were synthesized in the 1990s, but so far their structures have remained unknown due to their low crystallinity and disorder. The combination of 3D electron diffraction, X-ray powder diffraction, high-resolution transmission electron microscopy, structural modelling and diffraction simulations has enabled a comprehensive description of these two nanomaterials, revealng a new framework topology and a unique silica polymorph.
A step further in the comprehension of the magnetic coupling in gadolinium(III)-based carboxylate complexes
2013
Three new gadolinium(III) complexes of formula [Gd4(bta) 3(H2O)16]n·12nH2O (1), [Gd4(bta)3(H2O)12] n·18nH2O (2) and [Gd2(H 2bta)(bta)(H2O)2]n·4nH 2O (3) (H4bta = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and their structures determined by X-ray diffraction. 1 and 3 are three-dimensional compounds whereas 2 exhibits a two-dimensional structure. The ability of the bta4- to adopt different coordination modes accounts for these high dimensionalities although it precludes a rational structural design. The structures of 1-3 have in common the double oxo-carboxylate bridge between gadolinium(III) ions (μ-O: κ2O,O′) either as a discrete units (1 and 2) or as a chain (3) and one (3)…
Linker depletion for missing cluster defects in non-UiO Metal-Organic Frameworks
2021
Defect engineering is a valuable tool to tune the properties of metal–organic frameworks. However, defect chemistry remains still predominantly limited to UiO-type MOFs. We describe the preferential formation of missing cluster defects in heterometallic titanium–organic frameworks of the MUV-10 family when synthesised in sub-stoichiometric linker conditions. Our results show the value of integrating experimental work, computational modelling and thorough characterization in rationalizing the impact of defects over the porosity and structure of this family of materials. Correlation of experiment with computational models reveals the dominance of missing cluster vacancies in the pore size dis…
Varieties of Codes and Kraft Inequality
2007
Decipherability conditions for codes are investigated by using the approach of Guzman, who introduced in [7] the notion of variety of codes and established a connection between classes of codes and varieties of monoids. The class of Uniquely Decipherable (UD) codes is a special case of variety of codes, corresponding to the variety of all monoids. It is well known that the Kraft inequality is a necessary condition for UD codes, but it is not sufficient, in the sense that there exist codes that are not UD and that satisfy the Kraft inequality. The main result of the present paper states that, given a variety V of codes, if all the elements of V satisfy the Kraft inequality, then V is the var…
Varieties of Codes and Kraft Inequality
2005
Decipherability conditions for codes are investigated by using the approach of Guzman, who introduced in [7] the notion of variety of codes and established a connection between classes of codes and varieties of monoids. The class of Uniquely Decipherable (UD) codes is a special case of variety of codes, corresponding to the variety of all monoids. It is well known that the Kraft inequality is a necessary condition for UD codes, but it is not sufficient, in the sense that there exist codes that are not UD and that satisfy the Kraft inequality. The main result of the present paper states that, given a variety $\mathcal{V}$ of codes, if all the elements of $\mathcal{V}$ satisfy the Kraft inequ…
Time-Efficient Quantum Walks for 3-Distinctness
2013
We present two quantum walk algorithms for 3-Distinctness. Both algorithms have time complexity $\tilde{O}(n^{5/7})$, improving the previous $\tilde{O}(n^{3/4})$ and matching the best known upper bound for query complexity (obtained via learning graphs) up to log factors. The first algorithm is based on a connection between quantum walks and electric networks. The second algorithm uses an extension of the quantum walk search framework that facilitates quantum walks with nested updates.