Cadmium(II)‐Catalyzed C?N Cross‐Coupling of Amines with Aryl Iodides

Cadmium diacetate dihydrate [Cd(OAc)₂⋅2 H₂O] in combination with ethylene glycol catalyzes efficiently the C N cross‐coupling of amines with aryl iodides by a benzyne mechanism. Alkyl, aryl and heterocyclic amines are compatible with this system affording the aminated products in high to excellent yield.     

Materials selection using complex proportional assessment and evaluation of mixed data methods

Material selection is a very fast growing multi-criteria decision-making (MCDM) problem involving a large number of factors influencing the selection process. Proper choice of material is a critical issue for the success and competitiveness of the manufacturing organizations in the global market. Selection of the most appropriate material for a particular engineering application is a time consuming and expensive process where several candidate materials available in the market are taken into consideration as the tentative alternatives. Although a large number of mathematical approaches is now available to evaluate, select and rank the alternative materials for a given engineering application, this paper explores the applicability and capability of two almost new MCDM methods, i.e. complex proportional assessment (COPRAS) and evaluation of mixed data (EVAMIX) methods for materials selection. These two methods are used to rank the alternative materials, for which several requirements are considered simultaneously. Two illustrative examples are cited which prove that these two MCDM methods can be effectively applied to solve the real time material selection problems. In each example, a list of all the possible choices from the best to the worst suitable materials is obtained which almost match with the rankings as derived by the past researchers.     

Adapting the Network Interface for High-Performance Computing: The CNI Approach

As the prices of commodity workstations go down, clusters of workstations have started to emerge as a viable economic solution for scalable computing. Recent advances in networking technology have made it possible to obtain high-bandwidth connections between applications. However, the interconnect latency between workstation nodes in a cluster remains a serious concern and can prove to be the limiting factor in workstation performance. In this paper, we present the CNI orcluster network interface that achieves the twin goals of low latency and high bandwidth. In addition, CNI efficiently supports multiple programming paradigms for programming generality. This is done by functionally coupling the network interface more closely to the CPU without violating the constraints of a standard workstation architecture, CNI results in performance gains for applications, substantially reducing communication overhead and delay.     

Phenyliodine Diacetate‐Mediated Intramolecular C(sp2)?H Amidation for 1,2‐Disubstituted Benzimidazole Synthesis under Metal‐Free Conditions

A transition metal‐free, hypervalent iodine(III) reagent [phenyliodine diacetate (PIDA)]‐mediated C(sp²) H amidation in trifluoroethanol (TFE) has been developed. The intramolecular coupling methodology presented here provides a direct access to 1,2‐disubstituted multifunctional benzimidazoles in good to excellent yields. The reactions were performed in the open air and at ambient temperature, and were found to be eco‐friendly and atom‐economical.

     

Localized Surface Modification of Low-Thermal-Conductivity Brittle Solids

A new method utilizing temporal and spatial control of a CO₂ laser beam to generate temperatures sufficient to melt and fuse a vitreous material without concomitant development of crack-inducing thermal gradients has been developed for the localized surface modification and repair of small manufacturing defects in brittle and low-thermal-conductivity solids. Heat transfer and mechanical modeling of the process have allowed development of specialized heating algorithms. Low-positive-expansion frits with low glass transition temperature also have been developed that enable rapid treatment of small areas without the generation of parasitic critical stresses.     

Stabilized gold clusters: from isolation toward controlled synthesis

Bare metal clusters with fewer than ～100 atoms exhibit intrinsically unique and size-specific properties, making them promising functional units or building blocks for novel materials. To utilize such clusters in functional materials, they need to be stabilized against coalescence by employing organic ligands, polymers, and solid materials. To realize rational development of cluster-based materials, it is essential to clarify how the stability and nature of clusters are modified by interactions with stabilizers by characterizing isolated clusters. The next stage is to design on-demand function by intentionally controlling the structural parameters of cluster-based materials; such parameters include the size, composition, and atomic arrangement of clusters and the interfacial structure between clusters and stabilizers. This review summarizes the current state of the art of isolation of gold clusters stabilized in various environments and surveys ongoing efforts to precisely control the structural parameters with atomic level accuracy.     

A supervised learning algorithm for hierarchical classification of fuzzy patterns

The notion of “fuzzy separability” is introduced for fuzzy sets of patterns. A supervised learning algorithm is proposed for estimation of membership functions that yield hierarchical partitioning of the feature space for fuzzy separable pattern classes under confusion. Finally we present a methodology for the design of a classifier composed of hierarchical binary decision trees.     

Alpha-quartz 1. Crystallography and crystal defects

Crystallography of alpha-quartz is discussed with special reference to the existing ambiguities regarding handedness of its enantiomorphic forms and a mnemonic has been suggested. Previous x-ray diffraction topographic studies of synthetic quartz are critically reviewed and analysed to understand the origin, nature and location of dislocations. It is suggested that dislocations associated with cell boundaries, characteristic of the Z-zone grown portions of synthetic quartz, are pure a-type edge dislocations but possibly with an alternating non-conservative climb component associated with the predominating glide component.     

Surfactant controlled synthesis of crystalline phosphovanadate nanorods

Phosphovanadate nanorods were obtained in a reaction of vanadium (V) oxide as a precursor and a cationic surfactant, dodecylpyridinium chloride, as structure directing template at pH ∼3 at room temperature. The composition and morphology of the nanorods was established by powder X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), fourier transform infra-red spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The obtained nanorods have diameters of 40-60 nm with lengths up to 1 μm. The effect of reaction parameters such as concentration of surfactant and pH of the solution on the growth of nanorods has been investigated. A plausible mechanism involving the coalescence of nanoparticle ‘seeds’ leading to one-dimensional nanorods is also discussed. The same reaction when performed under hydrothermal condition, keeping other reaction parameters unchanged, resulted in the formation of phosphovanadate nanospheres of diameter 10-15 nm.