1,060 research outputs found
Coal desulfurization by low temperature chlorinolysis, phase 2
An engineering scale reactor system was constructed and operated for the evaluation of five high sulfur bituminous coals obtained from Kentucky, Ohio, and Illinois. Forty-four test runs were conducted under conditions of 100 by 200 mesh coal,solvents - methlychloroform and water, 60 to 130 C, 0 to 60 psig, 45 to 90 minutes, and gaseous chlorine flow rate of up to 24 SCFH. Sulfur removals demonstrated for the five coals were: maximum total sulfur removal of 46 to 89% (4 of 5 coals with methylchloroform) and 0 to 24% with water. In addition, an integrated continuous flow mini-pilot plant was designed and constructed for a nominal coal rate of 2 kilograms/hour which will be operated as part of the follow-on program. Equipment flow sheets and design drawings are included for both the batch and continuous flow mini-pilot plants
Making connections—strategies for single molecule fluorescence biophysics
Fluorescence spectroscopy and fluorescence microscopy
carried out on the single molecule level are elegant methods to
decipher complex biological systems; it can provide a wealth of
information that frequently is obscured in the averaging of
ensemble measurements. Fluorescence can be used to
localise a molecule, study its binding with interaction partners
and ligands, or to follow conformational changes in large
multicomponent systems. Efficient labelling of proteins and
nucleic acids is very important for any fluorescence method,
and equally the development of novel fluorophores has been
crucial in making biomolecules amenable to single molecule
fluorescence methods. In this paper we review novel coupling
strategies that permit site-specific and efficient labelling of proteins. Furthermore, we will discuss progressive single molecule approaches that allow the detection of individual molecules and biomolecular complexes even directly isolated from cellular extracts at much higher and much lower concentrations than has been possible so far
Thermal comfort optimisation of vernacular rural buildings::passive solutions to retrofit a typical farmhouse in central Italy
An adequate retrofitting of traditional rural buildings requires to preserve their formal characteristics and to understand the constructive elements that compose them and which are different in different geographical areas. This paper analyses the typical farmhouses in central Italy. Starting from the definition of a vernacular building model, the paper analyses its performance in terms of thermal comfort and energy efficiency. The methodology involves the use of energy dynamic simulations coupled with optimisation techniques aimed to identify the best combinations of insulating materials in terms of choice of material and its optimal location in the envelope. The paper demonstrates the good thermal and energy performance of farmhouses in central Italy. The results of the optimisation process showed that in these buildings, with the addition of insulation materials with low conductivity the perceived discomfort in the inhabited areas of the building can be reduced by 79% and the energy consumption related to heating can be reduced by 77%. The level of insulation of the pavement that separates the ground and first floor needs to be more moderate to promote the heat flow between floors during summer. The sensitivity analysis shows that the most influential component for thermal comfort is the roof insulation.</p
Same same but different: the evolution of TBP in archaea and their eukaryotic offspring
Transcription factors TBP and TF(II)B assemble with RNA polymerase and the promoter DNA forming the initiation complex. Despite a high degree of conservation, the molecular binding mechanisms of archaeal and eukaryotic TBP and TF(II)B differ significantly. Based on recent biophysical data, we speculate how the mechanisms co-evolved with transcription regulation and TBP multiplicity
Heat transfer and pressure drop in the main heat exchanger of a cryogenic mixed refrigerant cycle
Mixed refrigerant cycles (MRCs) offer a cost- and energy-efficient cooling method for the temperature range between 80 and 200 K. The performance of MRCs is substantially influenced by entropy production in the main heat exchanger. Due to the wide-boiling refrigerant mixtures applied in MRCs, a reliable design of the heat exchangers is challenging as two-phase heat transfer and pressure drop in both fluid streams must be considered simultaneously.
This contribution presents a literature review on the boiling/condensation heat transfer and pressure drop of zeotropic mixtures at low temperatures. Based on this survey, suitable correlations for the design of MRC heat exchangers are identified
History-sensitive versus future-sensitive approaches to security in distributed systems
We consider the use of aspect-oriented techniques as a flexible way to deal
with security policies in distributed systems. Recent work suggests to use
aspects for analysing the future behaviour of programs and to make access
control decisions based on this; this gives the flavour of dealing with
information flow rather than mere access control. We show in this paper that it
is beneficial to augment this approach with history-based components as is the
traditional approach in reference monitor-based approaches to mandatory access
control. Our developments are performed in an aspect-oriented coordination
language aiming to describe the Bell-LaPadula policy as elegantly as possible.
Furthermore, the resulting language has the capability of combining both
history- and future-sensitive policies, providing even more flexibility and
power.Comment: In Proceedings ICE 2010, arXiv:1010.530
Histaminylation of glutamine residues is a novel posttranslational modification implicated in G-protein signaling
Posttranslational modifications (PTM) have been shown to be essential for protein function and signaling. Here we report the identification of a novel modification, protein transfer of histamine, and provide evidence for its function in G protein signaling. Histamine, known as neurotransmitter and mediator of the inflammatory response, was found incorporated into mastocytoma proteins. Histaminylation was dependent on transglutaminase II. Mass spectrometry confirmed histamine modification of the small and heterotrimeric G proteins Cdc42, Galphao1 and Galphaq. The modification was specific for glutamine residues in the catalytic core, and triggered their constitutive activation. TGM2-mediated histaminylation is thus a novel PTM that functions in G protein signaling. Protein alphamonoaminylations, thus including histaminylation, serotonylation, dopaminylation and norepinephrinylation, hence emerge as a novel class of regulatory PTMs
A non-interleaving process calculus for multi-party synchronisation
We introduce the wire calculus. Its dynamic features are inspired by Milner's
CCS: a unary prefix operation, binary choice and a standard recursion
construct. Instead of an interleaving parallel composition operator there are
operators for synchronisation along a common boundary and non-communicating
parallel composition. The (operational) semantics is a labelled transition
system obtained with SOS rules. Bisimilarity is a congruence with respect to
the operators of the language. Quotienting terms by bisimilarity results in a
compact closed category
Integrated Structure and Semantics for Reo Connectors and Petri Nets
In this paper, we present an integrated structural and behavioral model of
Reo connectors and Petri nets, allowing a direct comparison of the two
concurrency models. For this purpose, we introduce a notion of connectors which
consist of a number of interconnected, user-defined primitives with fixed
behavior. While the structure of connectors resembles hypergraphs, their
semantics is given in terms of so-called port automata. We define both models
in a categorical setting where composition operations can be elegantly defined
and integrated. Specifically, we formalize structural gluings of connectors as
pushouts, and joins of port automata as pullbacks. We then define a semantical
functor from the connector to the port automata category which preserves this
composition. We further show how to encode Reo connectors and Petri nets into
this model and indicate applications to dynamic reconfigurations modeled using
double pushout graph transformation
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