994 research outputs found
Hybrid mimetic finite-difference and virtual element formulation for coupled poromechanics
We present a hybrid mimetic finite-difference and virtual element formulation
for coupled single-phase poromechanics on unstructured meshes. The key
advantage of the scheme is that it is convergent on complex meshes containing
highly distorted cells with arbitrary shapes. We use a local pressure-jump
stabilization method based on unstructured macro-elements to prevent the
development of spurious pressure modes in incompressible problems approaching
undrained conditions. A scalable linear solution strategy is obtained using a
block-triangular preconditioner designed specifically for the saddle-point
systems arising from the proposed discretization. The accuracy and efficiency
of our approach are demonstrated numerically on two-dimensional benchmark
problems.Comment: 25 pages, 17 figure
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Advancements in low NOx tangential firing systems
The most cost effective method of reducing nitrogen oxide emissions when burning fossil fuels, such as coal, is through in-furnace NOx reduction processes. ABB Combustion Engineering, Inc. (ABB CE), through its ABB Power Plant Laboratories has been involved in the development of such low NOx pulverized coal firing systems for many years. This development effort is most recently demonstrated through ABB CE`s involvement with the U.S. Department of Energy`s (DOE) {open_quotes}Engineering Development of Advanced Coal Fired Low-Emission Boiler Systems{close_quotes} (LEBS) project. The goal of the DOE LEBS project is to use {open_quotes}near term{close_quotes} technologies to produce a commercially viable, low emissions boiler. This paper addresses one of the key technologies within this project, the NOx control subsystem. The foundation for the work undertaken at ABB CE is the TFS 2000{trademark} firing system, which is currently offered on a commercial basis. This system encompasses sub-stoichiometric combustion in the main firing zone for reduced NOx formation. Potential enhancements to this firing system focus on optimizing the introduction of the air and fuel within the primary windbox to provide additional horizontal and vertical staging. As is the case with all in-furnace NOx control processes, it is necessary to operate the system in a manner which does not decrease NOx at the expense of reduced combustion efficiency
Modelling Opportunity Cost Effects in Money Demand due to Openness
We apply a novel model-based approach to constructing composite international financial indices (CIFIs) as measures of opportunity cost effects that arise due to openness in money demand models. These indices are tested on the People’s Republic of China (PRC) and Taiwan Province of China (TPC), two economies which differ substantially in size and degree of financial openness. Results show that (a) stable money demand equations can be identified if accounting for foreign opportunity costs through CIFIs, (b) the monetary policy intervention in the PRC over the global financial crisis period temporarily mitigated disequilibrating foreign shocks to money demand, (c) CIFIs capture opportunity costs due to openness more adequately than commonly used US interest rates and (d) CIFI construction provides valuable insights into the channels through which foreign financial markets affect domestic money demand
Modelling Opportunity Cost Effects in Money Demand due to Openness
We apply a novel model-based approach to constructing composite international financial indices (CIFIs) as measures of opportunity cost effects that arise due to openness in money demand models. These indices are tested on the People’s Republic of China (PRC) and Taiwan Province of China (TPC), two economies which differ substantially in size and degree of financial openness. Results show that (a) stable money demand equations can be identified if accounting for foreign opportunity costs through CIFIs, (b) the monetary policy intervention in the PRC over the global financial crisis period temporarily mitigated disequilibrating foreign shocks to money demand, (c) CIFIs capture opportunity costs due to openness more adequately than commonly used US interest rates and (d) CIFI construction provides valuable insights into the channels through which foreign financial markets affect domestic money demand
Expression and Purification of Z Protein from Junín Virus
Arenaviridae comprises 23 recognized virus species with a bipartite ssRNA genome and an ambisense coding strategy. The virions are enveloped and include nonequimolar amounts of each genomic RNA species, designated L and S, coding for four ORFs (N, GPC, L, and Z). The arenavirus Junín (JUNV) is the etiological agent of Argentine Hemorrhagic Fever, an acute disease with high mortality rate. It has been proposed that Z is the functional counterpart of the matrix proteins found in other negative-stranded enveloped RNA viruses. Here we report the optimized expression of a synthetic gene of Z protein, using three expression systems (two bacterial and a baculoviral one). One of these recombinant proteins was used to generate antibodies. A bioinformatic analysis was made where Z was subdivided into three domains. The data presented contributes methodologies for Z recombinant production and provides the basis for the development of new experiments to test its function
A new, very massive modular Liquid Argon Imaging Chamber to detect low energy off-axis neutrinos from the CNGS beam. (Project MODULAr)
The paper is considering an opportunity for the CERN/GranSasso (CNGS)
neutrino complex, concurrent time-wise with T2K and NOvA, to search for
theta_13 oscillations and CP violation. Compared with large water Cherenkov
(T2K) and fine grained scintillators (NOvA), the LAr-TPC offers a higher
detection efficiency and a lower backgrounds, since virtually all channels may
be unambiguously recognized. The present proposal, called MODULAr, describes a
20 kt fiducial volume LAr-TPC, following very closely the technology developed
for the ICARUS-T60o, and is focused on the following activities, for which we
seek an extended international collaboration:
(1) the neutrino beam from the CERN 400 GeV proton beam and an optimised horn
focussing, eventually with an increased intensity in the framework of the LHC
accelerator improvement program;
(2) A new experimental area LNGS-B, of at least 50000 m3 at 10 km off-axis
from the main Laboratory, eventually upgradable to larger sizes. A location is
under consideration at about 1.2 km equivalent water depth;
(3) A new LAr Imaging detector of at least 20 kt fiducial mass. Such an
increase in the volume over the current ICARUS T600 needs to be carefully
considered. It is concluded that a very large mass is best realised with a set
of many identical, independent units, each of 5 kt, "cloning" the technology of
the T600. Further phases may foresee extensions of MODULAr to meet future
physics goals.
The experiment might reasonably be operational in about 4/5 years, provided a
new hall is excavated in the vicinity of the Gran Sasso Laboratory and adequate
funding and participation are made available.Comment: Correspondig Author: C. Rubbia (E-mail: [email protected]), 33
pages, 11 figure
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