1,796 research outputs found
Liquid chromatography-tandem mass spectrometry - Application in the clinical laboratory
This review provides a concise survey of liquid chromatography tandem mass spectrometry (LCTMS) as an emerging technology in clinical chemistry. The combination of two mass spectrometers with an interposed collision cell characterizes LCTMS as an analytical technology on its own and not just as a more specific detector for HPLC compared with conventional techniques. In LCTMS, liquid chromatography is rather used for sample preparation but not for complete resolution of compounds of interest. The instrument technology of LCTMS is complex and comparatively expensive; however, in routine use, methods are far more rugged compared to conventional chromatographic techniques and enable highthroughput analyses with very limited manual handling steps. Moreover, compared to both gas chromatographymass spectrometry (GCMS) and conventional HPLC techniques, LCTMS is substantially more versatile with respect to the spectrum of analyzable compounds. For these reasons it is likely that LCTMS will gain far more widespread use in the clinical laboratory than HPLC and GCMS ever did. In this article, the key features of LCTMS are described, method development is explained, typical fields of application are discussed, and personal experiences are related
Resíduos Plásticos: capacitando a comunidade sobre reciclagem
Anais do 35º Seminário de Extensão Universitária da Região Sul - Área temática: Meio AmbienteA reciclagem, se conduzida de forma correta, traz inúmeros
benefícios ambientais, sociais e econômicos. Nesse aspecto foi desenvolvido um
projeto de pesquisa pelo LAPAM para a reciclagem de resíduos plásticos. Este
projeto contou com atividades de extensão de forma a capacitar selecionadores de
materiais recicláveis, comunidade acadêmica e setor empresarial através de
treinamento teórico-prático e workshop. As capacitações permitiram o intercâmbio de
experiências e conhecimentos, resultando na boa aceitação do público-alv
A critical analysis of The Moslem world, 1911-1947
The Moslem World was founded in 1911 by Dr. Samuel M. Zwemer with the dual mandate of providing information to the Christian West on the religion of Islam and aiding missionaries in their work of winning Muslims to Christ. Prior to the Journal's establishment little accurate information was available in the West on Islam's history, its creeds, beliefs and practices, and the lives of its adherents. This study has attempted to identify, categorize and analyze the manner and method by which the many facets of Islam were depicted in the pages of The Moslem World under Samuel Zwemer's editorship, 1911-1947. The conclusion drawn is that the Quarterly Review, rather than providing an objective account of Islam, thereby correcting historical inaccuracies, actually furthered negative stereotypes and popular misconceptions through a subjective misrepresentation of the faith. As Christianity was esteemed in the Journal as the pre-eminent faith and the only true religion, it was used as the model by which Islam was to be measured and subsequently judged to be in error. (Abstract shortened by UMI.
A Farewell to Liouvillians
We examine the Liouvillian approach to the quantum Hall plateau transition,
as introduced recently by Sinova, Meden, and Girvin [Phys. Rev. B {\bf 62},
2008 (2000)] and developed by Moore, Sinova and Zee [Phys. Rev. Lett. {\bf 87},
046801 (2001)]. We show that, despite appearances to the contrary, the
Liouvillian approach is not specific to the quantum mechanics of particles
moving in a single Landau level: we formulate it for a general disordered
single-particle Hamiltonian. We next examine the relationship between
Liouvillian perturbation theory and conventional calculations of
disorder-averaged products of Green functions and show that each term in
Liouvillian perturbation theory corresponds to a specific contribution to the
two-particle Green function. As a consequence, any Liouvillian approximation
scheme may be re-expressed in the language of Green functions. We illustrate
these ideas by applying Liouvillian methods, including their extension to Liouvillian flavors, to random matrix ensembles, using numerical
calculations for small integer and an analytic analysis for large .
We find that behavior at is different in qualitative ways from that
at . In particular, the limit expressed using Green
functions generates a pathological approximation, in which two-particle
correlation functions fail to factorize correctly at large separations of their
energy, and exhibit spurious singularities inside the band of random matrix
energy levels. We also consider the large treatment of the quantum Hall
plateau transition, showing that the same undesirable features are present
there, too
Thermal Grease Evaluation for ATLAS Upgrade Micro-Strip Detector.
The ATLAS upgrade detector foreseen at the phase 2 upgrade of LHC requires a complete new inner detector using silicon pixel and strip detectors. For both technologies, a specific mechanical and thermal design is required. Such a design may use soft thermal interfaces such as grease between the various parts. One foreseeable use would be between the cooling pipe and the thermal block allowing the strip modules to be decoupled from the mechanical and cooling structure. This note describes the technique used and the results obtained when characterizing a few grease samples. The results have been compared with thermal FEA simulations. A thermal conductivity measurement for each sample could be extracted from the measurements, with a systematic uncertainty of less than 6%. Some samples were irradiated to the expected fluence at sLHC and their resulting thermal conductivity compared with the non-irradiated samples
Studying functions on coral reefs : past perspectives, current conundrums, and future potential
This work was funded by the Australian Research Council (DRB; grant number FL190100062).Function-based studies have opened a new chapter in our understanding of coral reefs. Unfortunately, we are opening this chapter as the world’s reefs rapidly transform. In this context, one of the most important roles of function-based studies is to inform coral reef conservation. At this critical juncture, we have a chance to reflect on where we have come from, and where we are going, in coral reef functional ecology, with specific consideration of what this means for our approaches to conserving reefs. As focal examples, we examine the role of corals on reefs, and the practice of culling crown-of-thorns starfish, from a functional perspective. We also consider how the papers in this special issue build on our current understanding. Ultimately, we highlight how robust scientific investigation, based on an understanding of ecosystem functions, will be key in helping us navigate reefs through the current coral reef crisis.Peer reviewe
- …