Glafka 2004: Spacetime Topology from the Tomographic Histories Approach I: Non-Relativistic Case

The tomographic histories approach is presented. As an inverse problem, we recover in an operational way the effective topology of the extended configuration space of a system. This means that from a series of experiments we get a set of points corresponding to events. The difference between effective and actual topology is drawn. We deduce the topology of the extended configuration space of a non-relativistic system, using certain concepts from the consistent histories approach to Quantum Mechanics, such as the notion of a record. A few remarks about the case of a relativistic system, preparing the ground for a forthcoming paper sequel to this, are made in the end.     

Metal-organotetraphosphonate inorganic-organic hybrids: crystal structure and anticorrosion effects of zinc hexamethylenediaminetetrakis(methylenephosphonate) on carbon steels

The synthesis and structural characterization of the first polymeric M-HDTMP organic-inorganic hybrids are described [M = Zn2+, Ca2+; HDTMP = hexamethylenediaminetetrakis(methylenephosphonate)]. The 3D crystal structure of the Zn2+ analogue [Zn(HDTMP) x H2O] is described. The Zn center is found in a distorted octahedral environment of phosphonate oxygens. There is a long Zn...O interaction (2.622 A) originating from a protonated -P-OH group. Synergistic combinations of Zn2+ and the tetraphosphonate are found to form films that protect against the corrosion of carbon steels.     

Total synthesis of psammaplysenes A and B, naturally occurring inhibitors of FOXO1a nuclear export

[reaction: see text] Two inhibitors of FOXO1a-mediated nuclear export, psammaplysenes A and B, have been synthesized by a flexible and efficient route. A common starting material, 4-iodophenol, was used to prepare both halves of these pseudosymmetric dibromotyrosine-derived metabolites.     

Hydromagnetic free convection flow through a porous medium between two parallel plates

Steady hydromagnetic free convective flow of a conducting fluid through a porous medium bounded by two parallel plates is considered and effects of G (Grashof number) and the K (permeability parameter) on the velocity field are discussed.     

Stepwise,ring-closure synthesis and characterization of a homoleptic palladium(II)-pyrazolato cyclic trimer

A triangular homoleptic complex, [Pd(mu-3-Ph-pz)2]3, is prepared by the stepwise formation of an open-chain trimer and subsequent ring-closure; D3 molecular symmetry results from the one-directional arrangement of the unsymmetrically substituted pyrazolato ligands; the palladium atoms are held in close proximity, with Pd-Pd distances of 2.997(1)-3.087(1) A.     

A note on K-theory and triangulated derivators

In this paper we show an example of two differential graded algebras that have the same derivator K-theory but non-isomorphic Waldhausen K-theory. We also prove that Maltsiniotis?s comparison and localization conjectures for derivator K-theory cannot be simultaneously true.     

Quiescent crystallization of polypropylene: Experiments and modeling

The quiescent crystallization of several polypropylenes (PPs) was examined using Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy (POM). The half‐times of crystallization were obtained from the DSC thermographs employing the Avrami/Nakamura equation to fit and predict crystallization kinetics under isothermal and nonisothermal conditions. The induction times under nonisothermal conditions were estimated from isothermal crystallization data and used in conjunction with the Nakamura model in order to capture the crystallization behavior of the studied PPs. The Avrami/Nakamura model is found to fit and predict the nonisothermal crystallization data of the various PPs well over a range of cooling rates supporting its use in the simulation of polymer processes of industrial relevance. POM was used in line with parallel plate rheometry (Anton Paar, MCR 502) under no flow conditions to study the shape and growth rate of crystals of various PP resins at different temperatures or cooling rates. The growth rate of crystals is impeded exponentially with increase of temperature. The various PP resins of different molecular architecture have shown different nucleation and growth rate characteristics behavior under similar processing conditions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1259–1275     

Rheological characterization of polyethylene terephthalate resins using a multimode Phan-Tien-Tanner constitutive relation

Linear viscoelastic, shear, and extensional rheological characterization of linear and branched Poly(Ethylene Terephthalate) resins (PET) was carried out by means of both a parallel-plate and capillary rheometers. Before loading into the rheometers, the polymer pellets were thoroughly dried at well-characterized conditions long enough to obtain consistent and reproducible results. Continuing polymer degradation and poly-condensation reactions in the relatively open environment of the parallel-plate rheometer were accounted for by correcting the data using material-time super-position. The rheological data obtained were used to fit by nonlinear optimization, the linear relaxation spectrum and nonlinear parameters of a multi-mode Phan-Thien and Tanner (PTT) constitutive relation. It was found that this model can represent rheological data for PET resins very well and as a result may be used in relevant processing flow simulations, i.e. film casting.