Differential non-destructive image current detection in a fourier transform quadrupole ion trap

Dual-detector differential non-destructive Fourier transform detection in a quadrupole ion trap is shown to improve signal intensity and reduce noise compared with spectra recorded using a single detector. A larger area detector in each end-cap electrode is machined to fit its hyperbolic shape and so minimize field imperfections on the z-axis. Argon, acetophenone and bromobenzene spectra were recorded to allow a comparison between single- and dual-detector (differential) modes of detection and to demonstrate the improvement achieved with differential detection. Copyright 1999 John Wiley & Sons, Ltd.     

Pseudo-steady-state solutions for solidification in a wedge

Polubarinova-Kochina's analytical differential equation methodis used to determine the pseudo-steady-state solution to problemsinvolving the freezing (solidification) of wedges of liquidwhich are initially at their fusion temperature. In particular,we consider four distinct problems for wedges which are: freezingwith the same constant boundary temperature, freezing with thesame constant boundary heat fluxes, freezing with distinct constantboundary temperatures and freezing with distinct constant fluxesat the boundaries. For the last two problems, a Heun's differentialequation with an unknown singularity is derived, which in bothcases admits a particularly elegant simple solution for thespecial case when the wedge angle is . The moving boundariesobtained are shown pictorially.     

Secondary Metabolites Found among the Species Trattinnickia rhoifolia Willd

Plant-derived products may represent promising strategies in the treatment of Neglected Tropical Diseases (NTDs). From this perspective, it is observed that the Amazon phytogeographic region contains the tribe Canarieae of the Burseraceae family, composed of trees and shrubs supplied with resin channels. Its uses in folk medicine are related to aromatic properties, which have numerous medicinal applications and are present in reports from traditional peoples, sometimes as the only therapeutic resource. Despite its economic and pharmacological importance in the region, and although the family is distributed in all tropical and subtropical regions of the world, most of the scientific information available is limited to Asian and African species. Therefore, the present work aimed to review the secondary metabolites with possible pharmacological potential of the species Trattinnickia rhoifolia Willd, popularly known as “Breu sucuruba”. To this end, an identification key was created for chemical compounds with greater occurrence in the literature of the genus Trattinnickia. The most evident therapeutic activities in the consulted studies were antimicrobial, antioxidant, anti-inflammatory, antiviral, antifungal, anesthetic and antiparasitic. An expressive chemical and pharmacological relevance of the species was identified, although its potential is insufficiently explored, mainly in the face of the NTDs present in the Brazilian Amazon.     

Conformal foliations and constraint quantization

We show that the Classical Constraint Algebra of a Parametrized Relativistic Gauge System induces a natural structure of Conformal Foliation on a Transversal Gauge. Using the theory of conformal foliations, we provide a natural Factor Ordering for the quantum operators associated to the canonical quantization of such gauge system.