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Optimization of Dividing Wall Distillation Columns
The dividing wall distillation column (DWC) is an energy efficient configuration, capable of a high purity tertiary separation within a single column.1 DWCâs are an alternative to the standard two distillation column configuration. A DWC includes additional degrees of freedom, making modeling and optimization more complex than standard distillation columns.1 This study compiles results from previous DWC pilot columns into a process simulation to validate the method. Three pilot DWC columns were studied - the results of the three DWC column configurations (one four-product DWC and two three-product DWCs) were reconstructed using Aspen PlusTM and the product streams from the resulting simulations were compared to those provided in the authorsâ papers.10-12 Each model is optimized using HEEDSÂź, a multidisciplinary optimization software that tests hundreds of design cases and analyze their results. From a base case simulation, the optimization software varied the DWC design parameters (number of stages, feed location, reboiler duty, etc.) across a specified range. Using the SHERPA optimization method, the objective function of HEEDSÂź was set to minimize/maximize the key process parameters used to design a DWC. From the simulations, the âbestâ design is determined, heat transfer is implemented, and a scale-up for each optimized design is conducted. HEEDSÂź in combination with Aspen PlusTM forms a powerful and efficient tool for the optimization of DWC simulations and designs and the reduction in time and simple user interface allows for many opportunities to test the various complicated design characteristics of the DWC.Chemical Engineerin
A Preliminary Model of the Hydrologic-Sociologic Flow System of an Urban Area
This report describes the first phase of a larger study which is directed toward the development of a general technique for analyzing and solving urban metropolitan hydrologic problems through a joint consideration of both the physical and social dimensions. This report is limited to the preliminary work of identification of social variables, the first steps in assigning mathematical values to them, and developing a mathematical format for these variables. In addition, the physical-hydrologic system is identified for purposes of clarifying the elements in that system. The ultimate objective of the entire study is directed toward discovering a theoretical and generally applicable mathematical model of both the physical and social dimensions involved in metropolitan flooding problems
Computing in Additive Networks with Bounded-Information Codes
This paper studies the theory of the additive wireless network model, in
which the received signal is abstracted as an addition of the transmitted
signals. Our central observation is that the crucial challenge for computing in
this model is not high contention, as assumed previously, but rather
guaranteeing a bounded amount of \emph{information} in each neighborhood per
round, a property that we show is achievable using a new random coding
technique.
Technically, we provide efficient algorithms for fundamental distributed
tasks in additive networks, such as solving various symmetry breaking problems,
approximating network parameters, and solving an \emph{asymmetry revealing}
problem such as computing a maximal input.
The key method used is a novel random coding technique that allows a node to
successfully decode the received information, as long as it does not contain
too many distinct values. We then design our algorithms to produce a limited
amount of information in each neighborhood in order to leverage our enriched
toolbox for computing in additive networks
Mucosal injury following short term tracheal intubation: a novel animal model and composite injury score
Objectives: Postintubation laryngotracheal injury is common. Assessment of histopathological changes currently requires animal models. We set about developing a viable, resource effective animal model to study these effects and to develop a detailed tissue injury score.
Methods: Six pigs were anaesthetised using a standard regimen. We intubated the tracheas using a standard endotracheal tube modified to include optical sensors. Animals were anaesthetised for a duration of two to four hours, and their lungs were ventilated using a normoxic gas mixture. Following euthanasia, the tracheas were removed and underwent histological assessment by two independent veterinary pathologists. The histological lesions, including controls, were described and quantified, and two pathologists classified tissues according to a novel injury score.
Results: Mean duration of tracheal intubation was 191 minutes (SD±41.6). In all except one animal, cuff pressures were maintained in the range of 25 â 45 cmH20. Histopathological findings in all study animals showed more extensive changes than previously described with short-term intubation. Changes were seen in all mucosal layers consistent with acute, suppurative and ulcerative tracheitis. The range of scores of the developed composite scoring system among the animals was wider than in earlier descriptions. There was a high percentage of agreement between both pathologists.
Conclusions: We have described a novel tissue injury score to assess pathological changes following short term intubation in a viable animal model. The scoring system distinguished between the test animals as well as controls and may be appropriate for continuing study of intubation injury
Olanzapine-Induced Hyperphagia and Weight Gain Associate with Orexigenic Hypothalamic Neuropeptide Signaling without Concomitant AMPK Phosphorylation
The success of antipsychotic drug treatment in patients with schizophrenia is limited by the propensity of these drugs to induce hyperphagia, weight gain and other metabolic disturbances, particularly evident for olanzapine and clozapine. However, the molecular mechanisms involved in antipsychotic-induced hyperphagia remain unclear. Here, we investigate the effect of olanzapine administration on the regulation of hypothalamic mechanisms controlling food intake, namely neuropeptide expression and AMP-activated protein kinase (AMPK) phosphorylation in rats. Our results show that subchronic exposure to olanzapine upregulates neuropeptide Y (NPY) and agouti related protein (AgRP) and downregulates proopiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC). This effect was evident both in rats fed ad libitum and in pair-fed rats. Of note, despite weight gain and increased expression of orexigenic neuropeptides, subchronic administration of olanzapine decreased AMPK phosphorylation levels. This reduction in AMPK was not observed after acute administration of either olanzapine or clozapine. Overall, our data suggest that olanzapine-induced hyperphagia is mediated through appropriate changes in hypothalamic neuropeptides, and that this effect does not require concomitant AMPK activation. Our data shed new light on the hypothalamic mechanism underlying antipsychotic-induced hyperphagia and weight gain, and provide the basis for alternative targets to control energy balance
Heterogeneity of Microglial Activation in the Innate Immune Response in the Brain
The immune response in the brain has been widely investigated and while many studies have focused on the proinflammatory cytotoxic response, the brainâs innate immune system demonstrates significant heterogeneity. Microglia, like other tissue macrophages, participate in repair and resolution processes after infection or injury to restore normal tissue homeostasis. This review examines the mechanisms that lead to reduction of self-toxicity and to repair and restructuring of the damaged extracellular matrix in the brain. Part of the resolution process involves switching macrophage functional activation to include reduction of proinflammatory mediators, increased production and release of anti-inflammatory cytokines, and production of cytoactive factors involved in repair and reconstruction of the damaged brain. Two partially overlapping and complimentary functional macrophage states have been identified and are called alternative activation and acquired deactivation. The immunosuppressive and repair processes of each of these states and how alternative activation and acquired deactivation participate in chronic neuroinflammation in the brain are discussed
Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment
The Deep Underground Neutrino Experiment (DUNE) will produce world-leading
neutrino oscillation measurements over the lifetime of the experiment. In this
work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in
the neutrino sector, and to resolve the mass ordering, for exposures of up to
100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed
uncertainties on the flux prediction, the neutrino interaction model, and
detector effects. We demonstrate that DUNE will be able to unambiguously
resolve the neutrino mass ordering at a 3 (5) level, with a 66
(100) kt-MW-yr far detector exposure, and has the ability to make strong
statements at significantly shorter exposures depending on the true value of
other oscillation parameters. We also show that DUNE has the potential to make
a robust measurement of CPV at a 3 level with a 100 kt-MW-yr exposure
for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2.
Additionally, the dependence of DUNE's sensitivity on the exposure taken in
neutrino-enhanced and antineutrino-enhanced running is discussed. An equal
fraction of exposure taken in each beam mode is found to be close to optimal
when considered over the entire space of interest
A Gaseous Argon-Based Near Detector to Enhance the Physics Capabilities of DUNE
This document presents the concept and physics case for a magnetized gaseous argon-based detector system (ND-GAr) for the Deep Underground Neutrino Experiment (DUNE) Near Detector. This detector system is required in order for DUNE to reach its full physics potential in the measurement of CP violation and in delivering precision measurements of oscillation parameters. In addition to its critical role in the long-baseline oscillation program, ND-GAr will extend the overall physics program of DUNE. The LBNF high-intensity proton beam will provide a large flux of neutrinos that is sampled by ND-GAr, enabling DUNE to discover new particles and search for new interactions and symmetries beyond those predicted in the Standard Model
Snowmass Neutrino Frontier: DUNE Physics Summary
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment with a primary physics goal of observing neutrino and antineutrino oscillation patterns to precisely measure the parameters governing long-baseline neutrino oscillation in a single experiment, and to test the three-flavor paradigm. DUNE's design has been developed by a large, international collaboration of scientists and engineers to have unique capability to measure neutrino oscillation as a function of energy in a broadband beam, to resolve degeneracy among oscillation parameters, and to control systematic uncertainty using the exquisite imaging capability of massive LArTPC far detector modules and an argon-based near detector. DUNE's neutrino oscillation measurements will unambiguously resolve the neutrino mass ordering and provide the sensitivity to discover CP violation in neutrinos for a wide range of possible values of ÎŽCP. DUNE is also uniquely sensitive to electron neutrinos from a galactic supernova burst, and to a broad range of physics beyond the Standard Model (BSM), including nucleon decays. DUNE is anticipated to begin collecting physics data with Phase I, an initial experiment configuration consisting of two far detector modules and a minimal suite of near detector components, with a 1.2 MW proton beam. To realize its extensive, world-leading physics potential requires the full scope of DUNE be completed in Phase II. The three Phase II upgrades are all necessary to achieve DUNE's physics goals: (1) addition of far detector modules three and four for a total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary muon spectrometer with a magnetized, high-pressure gaseous argon TPC and calorimeter
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