Synthesis, structure, transformation studies and catalytic properties of open-framework cadmium thiosulfate compounds

Five new thiosulfate based inorganic-organic hybrid open-framework compounds have been synthesized employing mild reaction conditions. Of the five compounds, [Na-2(H2O)(8)][Cd(C10H8N2)( S2O3)(2)]center dot 2H(2)O, I and [Cd-2(C10H8N2)(2)(HS2O3)(2)(S2O3)(2)][(C10H9N2)(2)(C10H8N2)(2)]center dot 8H(2)O, II have one-dimensional (1D) structures and [Cd(C10H8N2)(H2O)(2)(S2O3)]center dot 2H(2)O, III, [Cd-2(C10H8N2)(3)(S2O3)(2)], IV and [Cd-2(C10H8N2)(2.5)(S2O3)(2)], V have three- dimensional (3D) structures. The 1D structures are somewhat related, formed by the bonding between tetrahedral Cd centers (CdN2S2) and 4,4'-bipyridine (bpy) units. The inter-chain spaces are occupied by the hanging thiosulfate units in both the cases along with Na(H2O)(6) chains in I and free bpy units in II. The three 3D structures have one-dimensional cadmium thiosulfate chains linked by bpy units. Interpenetration has been observed in all the 3D structures. The 3D structures appear to be related and can be derived from fgs net. Transformation studies on the 1D compound, [Na-2(H2O)(8)][Cd(C10H8N2)(S2O3)(2)]center dot 2H(2)O, I, indicated a facile formation of [Cd(C10H8N2)(H2O)(2)(S2O3)]center dot 2H(2)O, III. Prolonged heating of I gave rise to a 3D cadmium sulfate phase, [Cd-2(C10H8N2)(2)(H2O)(3)(SO4)(2)]center dot 2H(2)O, VI. Compound VI has one-dimensional cadmium sulfate chains formed by six-membered rings connected by bpy units to form a 3D structure, which appears to resemble the topological arrangement of III. Transformation studies of III indicates the formation of IV and V, and at a higher temperature a new 3D cadmium sulfate, [Cd(C10H8N2)(SO4)], VII. Compound VII has a 4 x 4 grid cadmium sulfate layers pillared by bpy units. All the compounds were characterized by PXRD, TGA, IR and UV-visible studies. Preliminary studies on the possible use of the 3D compounds (III-VII) in heterogeneous cyanosilylation of imines appear to be promising.

On the use of a coordinate transformation for analysis of axisymmetric vibration of polar orthotropic annular plates

Estimates of natural frequencies corresponding to axisymmetric modes of flexural vibration of polar orthotropic annular plates have been obtained for various combinations of clamped, simply supported and free edge conditions. A coordinate transformation in the radial direction has been used to obtain effective solutions by the classical Rayleigh-Ritz method. The analysis with this transformation has been found to be advantageous in computations, particularly for large hole sizes, over direct analysis. Numerical results have been obtained for various values of hole sizes and rigidity ratio. The eigenvalue parameter has been found to vary more or less linearly with the rigidity ratio. A comparison with the results for isotropic plates has brought out some interesting features.

Service Productivity: Toward a Conceptualisation of the Transformation of inputs

The productivity of a process is related to how effectively input resources are transformed into value for customers. For the needs of manufacturers of physical products there are widely used productivity concepts and measurements instruments. However, in service processes the underlying assumptions of these concepts and models do not hold. For example, manufacturing-based productivity models assume that an altered configuration of input resources in the production process does not lead to quality changes in outputs (the constant-quality assumption). However, in a service context changes in the production resources and productions systems do affect the perceived quality of services. Therefore, using manufacturing-oriented productivity models in service contexts are likely to give managers wrong directions for action. Research into the productivity of services is still scarce, because of the lack of viable models. The purpose of the present article is to analyse the requirements for the development of a productivity concept for service operations. Based on the analysis, a service productivity model is developed. According to this model, service productivity is a function of 1) how effectively input resources into the service (production) process are transformed to outputs in the form of services (internal or cost efficiency), 2) how well the quality of the service process and its outcome is perceived (external or revenue efficiency), and 3) how effectively the capacity of the service process is utilised (capacity efficiency). In addition, directions for developing measurement models for service productivity are discussed.

Narratives of Travel and the Travelling Concept of Narrative: Genre Blending and the Art of Transformation

In this article I shall argue that understandings of what constitutes narrative, how it functions, and the contexts in which it applies have broadened in line with cultural, social and intellectual trends which have seen a blurring, if not the dissolution, of boundaries between ‘fact’ and ‘fiction’; ‘literary’ and ‘non-literary’ narrative spaces; history and story; concepts of time and space, text and image, teller and tale, representation and reality.To illustrate some of the ways in which the concept of narrative has travelled across disciplinary and generic boundaries, I shall look at The Art of Travel (de Botton 2003), with a view to demonstrating how the blending of genres works to produce a narrative that is at once personal and philosophical; visual and verbal; didactic and poetic. I shall show that such a text constitutes a site of interrogation of concepts of narrative, even as it depends on the reader’s ability to narrativize experience.

Synthesis, Structure, and Solid-State Transformation Studies of Phosphonoacetate Based Hybrid Compounds of Uranium and Thorium

Three new phosphonoacetate hybrid frameworks based on the actinide elements uranium and thorium have been synthesized. The compounds [C4N2H14][(UO2)(2)(O3PCH2COO)(2)]center dot H2O, I,[C4N2H14][(UO2)(2)(C2O4)(O3PCH2COOH)(2)], II, and Th(H2O)(2)(O3PCH2COO)(C2O4)(0.5). H2O, III, are built up from the connectivity between the metal polyhedra and the phosphonoacetate/oxalate units. Compound II has been prepared using a solvent-free approach, by a solid state reaction at 150 degrees C. It has been shown that II can also be prepared through a room temperature mechanochemical (grinding) route. The layer arrangement in III closely resembles to that observed in I. The compounds have been characterized by powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and fluorescence studies.

A generalised cole-hopf transformation for nonlinear parabolic and hyperbolic equations

The Cole-Hopf transformation has been generalized to generate a large class of nonlinear parabolic and hyperbolic equations which are exactly linearizable. These include model equations of exchange processes and turbulence. The methods to solve the corresponding linear equations have also been indicated.La transformation de Cole et de Hopf a été généralisée en vue d'engendrer une classe d'équations nonlinéaires paraboliques et hyperboliques qui peuvent être rendues linéaires de façon exacte. Elles comprennent des équations modèles de procédés d'échange et de turbulence. Les méthodes pour résoudre les équations linéaires correspondantes ont également été indiquées.

Anatase-rutile transformation in Fe/TiO2, Th/TiO2 and Cu/TiO2 catalysts and its possible role in metal-support interaction

Based on in-situ Mossbauer and X-ray diffraction studies, it is shown that in the Fe/TiO2 catalyst, the anatase-rutile transformation of the TiO2 support is facilitated by the Fe2+ ions formed during the reduction. The transformation occurs at lower temperatures in Th/TiO2 and Cu/TiO2 compared to pure TiO2. In general, the transformation of anatase to rutile seems to occur at or below the temperature (approximately 770 K) at which strong-metal-support-interaction manifests itself.

Structural synthesis by transformation of binary chains Strukturelle synthese durch umwandlung binaerer ketten

The paper presents a general method of structural synthesis which can be used to derive all possible simple- and multiple-jointed chains of positive, zero or negative degree-of-freedom. In this method all possible chains with N links and F degrees-of-freedom are derived by the transformation of the corresponding “binary chains” with N binary links and F degrees-of-freedom. The method is illustrated by applying to the case of chains with degrees-of-freedom 1,2,0 and −1.

A real transformation for modal analysis of flexible damped spacecraft

Modal approach is widely used for the analysis of dynamics of flexible structures. However, space analysts yet lack an intimate modal analysis of current spacecraft which are rich with flexibility and possess both structural and discrete damping. Mathematical modeling of such spacecraft incapacitates the existing real transformation procedure, for it cannot include discrete damping, demands uncomputable inversion of a modal matrix inaccessible due to its overwhelming size and does not permit truncation. On the other hand, complex transformation techniques entail more computational time and cannot handle structural damping. This paper presents a real transformation strategy which averts inversion of the associated real transformation matrix, allows truncation and accommodates both forms of damping simultaneously. This is accomplished by establishing a key relation between the real transformation matrix and its adjoint. The relation permits truncation of the matrices and leads to uncoupled pairs of coupled first order equations which contain a number of adjoint eigenvectors. Finally these pairs are solved to obtain a literal modal response of forced gyroscopic damped flexibile systems at arbitrary initial conditions.

Cox-2, tenascin, CRP, and ingraft chimerism in a model of post-transplant obliterative bronchiolitis

Chronic rejection in the form of obliterative bronchiolitis (OB) is the major cause of death 5 years after lung transplantation. The exact mechanism of OB remains unclear. This study focused on the role of cyclo-oxygenase (COX) -2, tenascin, and C-reactive protein (CRP) expression, and the occurrence of ingraft chimerism (= cells from two genetically distinct individuals in a same individual) in post-transplant OB development. In our porcine model, OB developed invariably in allografts, while autografts stayed patent. The histological changes were similar to those seen in human OB. In order to delay or prevent obliteration, animals were medicated according to certain protocol. In the beginning of the bronchial allograft reaction, COX-2 induction occurred in airway epithelial cells prior to luminal obliteration. COX-2 expression in macrophages and fibroblasts paralleled the onset of inflammation and fibroblast proliferation. This study demonstrated for the first time, that COX-2 expression is associated with the early stage of post- transplant obliterative airway disease. Tenascin expression in the respiratory epithelium appeared to be predictive of histologic features observed in human OB, and influx of immune cells. Expression in the bronchial wall and in the early obliterative lesions coincided with the onset of onset of fibroblast and inflammatory cell proliferation in the early stage of OB and was predictive of further influx of inflammatory and immune cells. CRP expression in the bronchial wall coincided with the remodelling process. High grade of bronchial wall CRP staining intensity predicted inflammation, accelerated fibroproliferation, and luminal obliteration, which are all features of OB. In the early obliterative plaque, majority of cells expressed CRP, but in mature, collagen-rich plaque, expression declined. Local CRP expression might be a response to inflammation and it might promote the development of OB. Early appearance of chimeric (= recipient-derived) cells in the graft airway epithelium predicted epithelial cell injury and obliteration of the bronchial lumen, which both are features of OB. Chimeric cells appeared in the airway epithelium after repair following transplantation-induced ischemic injury. Ingraft chimerism might be a mechanism to repair alloimmune-mediated tissue injury and to protect allografts from rejection after transplantation. The results of this study indicate, that COX-2, tenascin, CRP, and ingraft chimerism have a role in OB development. These findings increase the understanding of the mechanisms of OB, which may be beneficial in further development of diagnostic options.

A Vicarious One-Pot Transformation of a Fluorocyclitol to a Polycyclitol: Observation of a Formal 4-Fold Axial-Equatorial Epimerization on a Conformationally Locked Scaffold

A conformationally locked fluoropentol undergoes an interesting transformation to (trans,anti,trans,anti,trans)-perhydro-2,3,4a,6,7,8a-naphthalenehexol essentially under conditions of base-induced transesterification. The proposed rationale for the observed metamorphosis involves a nucleophilic displacement of fluoride, and subsequent stereo- and regioselective anti-Furst-Plattner-type ring-opening of the epoxide thus formed.