Instrument monitoring, data sharing, and archiving using Common Instrument Middleware Architecture (CIMA)

The Common Instrument Middleware Architecture (CIMA) aims at Grid-enabling a wide range of scientific instruments and sensors to enable easy access to and sharing and storage of data produced by these instruments and sensors. This paper describes the implementation of CIMA applied to the field of single-crystal X-ray crystallography. To allow the researchers to easily view the current and past data streams from the instruments or sensors in a laboratory, a crystallography portal and associated portlets were developed for this application. The CIMA-based crystallography system provides an opportunity for anyone with Web access to observe and use crystallographic and other data from laboratories that previously had only limited access.     

Polytopes with centrally symmetric faces

It is shown that if, for some 2≦j≦d-2, all thej-faces of ad-polytopeP are centrally symmetric, then all the faces ofP of every dimension are centrally symmetric.     

Simplices with Equiareal Faces

If all the edges of a d -simplex T have the same length, then T is regular. However, if d geq 3 , then it is clear that the facets of T may have the same (d-1) -volume without T being regular. Here, the question of the extent to which the equality of r -volumes of the r -faces of T implies regularity of T is investigated, the case r = d-2 proving most fruitful. Received January 30, 1999. Online publication May 19, 2000.     

Realizations of regular apeirotopes

Summary In an earlier paper, a theory of realizations of (finite) regular polytopes in euclidean spaces was developed. Here, the analogous problem of realizing regular apeirotopes (infinite polytopes) is investigated. While no complete theory is expounded, several basic results are established. Among these is the curious fact that, if a regular apeirotope has a discrete realization, then it has one with no translations in its symmetry group.     

Regular polytopes of type {4,4,3} and {4,4,4}

Abstract regular polytopes generalize the classical concept of a regular polytope and regular tessellation to more complicated combinatorial structures with a distinctive geometrical and topological flavour. In this paper the authors give an almost complete classification of the (universal) locally toroidal regular 4-polytopes of Schläfli types {4,4,3} and {4,4,4}.     

Procedure for the Rapid Synthesis of the Monomer 1,4-Bis(chloromethyl)-2-(2-ethylhexyloxy)-5-methoxybenzene

The alkylation of 4-methoxyphenol with 2-ethylhexyl bromide was accelerated by using potassium tert-butoxide in dimethylformamide. Subsequent chloromethylation occurred quickly using acetic acid as a cosolvent to give the poly[(2-(2-ethylhexyloxy)-5-methoxy-p-phenylene)vinylene] (MEH-PPV) monomer in 61% overall yield on a 2-mol scale.     

Photon Equivalents as a Parameter for Scaling Photoredox Reactions in Flow: Translation of Photocatalytic C−N Cross-Coupling from Lab Scale to Multikilogram Scale

With the development of new photocatalytic methods over recent decades, the translation of these chemical reactions to industrial-production scales using continuous-flow reactors has become a topic of increasing interest. In this context, we describe our studies toward elucidating an empirically derived parameter for scaling photocatalytic reactions in flow. By evaluating the performance of a photocatalytic C−N cross-coupling reaction across multiple reactor sizes and geometries, it was demonstrated that expressing product yield as a function of the absorbed photon equivalents provides a predictive, empirical scaling parameter. Through the use of this scaling factor and characterization of the photonic flux within each reactor, the cross-coupling was scaled successfully from the milligram scale in batch to a multi-kilogram reaction in flow.