24,422 research outputs found
Analytical development of the planetary disturbing function on a digital computer
Fortran II IBM 7094 computer program for analytical development of planetary disturbing functio
Transverse microcracking in Celion 6000/PMR-15 graphite-polyimide
The effects of room temperature tensile loading and five thermal loadings, in the range -320 F (-196C) to 625F (330CC), upon the development of transverse microcracks (TVM) in Celion 6000/PMR-15 graphite-polyimide laminates were investigated. Microcracks were observed using a replicating technique, microscopy and X-ray. The mechanical or thermal load at which microcracking initiates and the ply residual stresses were predicted using laminate analysis with stress- and temperature-dependent material properties
Absolute electrical impedance tomography (aEIT) guided ventilation therapy in critical care patients: simulations and future trends
Thoracic electrical impedance tomography (EIT) is a noninvasive, radiation-free monitoring technique whose aim is to reconstruct a cross-sectional image of the internal spatial distribution of conductivity from electrical measurements made by injecting small alternating currents via an electrode array placed on the surface of the thorax. The purpose of this paper is to discuss the fundamentals of EIT and demonstrate the principles of mechanical ventilation, lung recruitment, and EIT imaging on a comprehensive physiological model, which combines a model of respiratory mechanics, a model of the human lung absolute resistivity as a function of air content, and a 2-D finite-element mesh of the thorax to simulate EIT image reconstruction during mechanical ventilation. The overall model gives a good understanding of respiratory physiology and EIT monitoring techniques in mechanically ventilated patients. The model proposed here was able to reproduce consistent images of ventilation distribution in simulated acutely injured and collapsed lung conditions. A new advisory system architecture integrating a previously developed data-driven physiological model for continuous and noninvasive predictions of blood gas parameters with the regional lung function data/information generated from absolute EIT (aEIT) is proposed for monitoring and ventilator therapy management of critical care patients
An investigation into the effect of thickness of titanium dioxide and gold-silver nanoparticle titanium dioxide composite thin-films on photocatalytic activity and photo-induced oxygen production in a sacrificial system
Thin films of titanium dioxide and titanium dioxide with incorporated gold and silver nanoparticles were deposited onto glass microscope slides, steel and titanium foil coupons by two solâgel dip-coating methods. The film's photocatalytic activity and ability to evolve oxygen in a sacrificial solution were assessed. It was found that photocatalytic activity increased with film thickness (from 50 to 500 nm thick samples) for the photocatalytic degradation of methylene blue in solution and resazurin redox dye in an intelligent ink dye deposited on the surface. Contrastingly, an optimum film thickness of [similar]200 nm for both composite and pure films of titanium dioxide was found for water oxidation, using persulfate (S2O82â) as a sacrificial electron acceptor. The nanoparticle composite films showed significantly higher activity in oxygen evolution studies compared with plain TiO2 films
Do earplugs stop noise from driving critical care patients into delirium?
Quality sleep is a problem for the critically ill who are cared for in an environment where interventions night and day are common, staff members are constantly present in relatively high numbers, and treatment is accompanied by a range of changing warning tones and alarms and lights. These critical care units are generally designed without a focus on patient comfort, sleep, and rest and often lack access to appropriate natural daylight. To add to this problem, critical illness, particularly sepsis, disrupts circadian rhythms and sleep patterns, and disruption of circadian rhythms, in turn, impairs immunity and contributes to delirium. In a randomized controlled trial in the previous issue of Critical Care, Van Rompaey and colleagues have intervened to reduce noise, which is a key factor in this disruption, by having patients use earplugs at night. Delirium was assessed by using the NEECHAM (Neelon and Champagne) confusion scale, and sleep perception was assessed by patients' responses to a set of five questions. After the first night, patients reported a better sleep perception and the occurrence of delirium was reduced (hazard ratio of 0.47 for the development of delirium) or was delayed. The study did not quantify adequacy of pain control in post-surgical patients and used patient reporting to assess sleep. Whether patients were receiving respiratory or other organ support was not reported. The potential benefit of earplugs is an important practical finding that could be implemented in most intensive care units
Enumeration of quarter-turn symmetric alternating-sign matrices of odd order
It was shown by Kuperberg that the partition function of the square-ice model
related to the quarter-turn symmetric alternating-sign matrices of even order
is the product of two similar factors. We propose a square-ice model whose
states are in bijection with the quarter-turn symmetric alternating-sign
matrices of odd order, and show that the partition function of this model can
be also written in a similar way. This allows to prove, in particular, the
conjectures by Robbins related to the enumeration of the quarter-turn symmetric
alternating-sign matrices.Comment: 11 pages, 13 figures; minor correction
Cluster Dynamical Mean Field Theories
Cluster Dynamical Mean Field Theories are analyzed in terms of their
semiclassical limit and their causality properties, and a translation invariant
formulation of the cellular dynamical mean field theory, PCDMFT, is presented.
The semiclassical limit of the cluster methods is analyzed by applying them to
the Falikov-Kimball model in the limit of infinite Hubbard interaction U where
they map to different classical cluster schemes for the Ising model.
Furthermore the Cutkosky-t'Hooft-Veltman cutting equations are generalized and
derived for non translation invariant systems using the Schwinger-Keldysh
formalism. This provides a general setting to discuss causality properties of
cluster methods. To illustrate the method, we prove that PCDMFT is causal while
the nested cluster schemes (NCS) in general and the pair scheme in particular
are not. Constraints on further extension of these schemes are discussed.Comment: 26 page
Precautionary labelling of foods for allergen content: are we ready for a global framework?
© 2014 Allen et al.; licensee BioMed Central Ltd.Food allergy appears to be on the rise with the current mainstay of treatment centred on allergen avoidance. Mandatory allergen labelling has improved the safety of food for allergic consumers. However an additional form of voluntary labelling (termed precautionary allergen labelling) has evolved on a wide range of packaged goods, in a bid by manufacturers to minimise risk to customers, and the negative impact on business that might result from exposure to trace amounts of food allergen present during cross-contamination during production. This has resulted in near ubiquitous utilisation of a multitude of different precautionary allergen labels with subsequent confusion amongst many consumers as to their significance. The global nature of food production and manufacturing makes harmonisation of allergen labelling regulations across the world a matter of increasing importance. Addressing inconsistencies across countries with regards to labelling legislation, as well as improvement or even banning of precautionary allergy labelling are both likely to be significant steps forward in improved food safety for allergic families. This article outlines the current status of allergen labelling legislation around the world and reviews the value of current existing precautionary allergen labelling for the allergic consumer. We strongly urge for an international framework to be considered to help roadmap a solution to the weaknesses of the current systems, and discuss the role of legislation in facilitating this
Don't make value co-creation ambiguous, social networks simplify it
Purpose: Value co-creation is often necessary for situation where expertise and resources are beyond a single actor. Despite the vast study of value co-creation in service system by both academics and practitioners as an overarching theory, that describes collaboration between consumer and provider. More importantly, little is known about how value co-creation is established in social network analysis and there is little agreement on what depicts value co-creation. These missing concerns included; vast studies of value co-creation in dyadic relationships and sparingly in multi-actors, lack of study on theoretical and empirical features of value co-creation, lack of empirical investigation of strength of interactive relationships in networks for co-creation of specific value-in-use. These thought-provoking missing concerns necessitated this research by forwarding the question; âWhat are the features of social value co-creation in service system and how can it be established in social networksâ?
Methodology: A case study approach is employed using the exploratory sequential mixed methods. The contextual investigation was carried out in water supply system called KAMOMI. The KAMOMI water scheme provides water supply facility and has in place a service system consisting both the provider, consumers and different stakeholders. The case represents a service system where value co-creation occurs within actor-to-actor interactive relationships to benefit the community.
Findings: The paper argued that the examination of value co-creation among multi-actors in social networks analysis is highly significant to its cogency and generalisation. The qualitative analysis provided evident features of value co-creation, which transforms value co-creation from dyadic to multi-actors interpersonal interactive relationships in social network analysis. The value co-creation features included resource integrating networks, defined value-in-use, actorsâ empowerment, perceived ownership and knowledge sharing. Meanwhile, the quantitative analysis discovered that closeness of both formal and informal relationships; including frequency of informal interactions enable access to integration of resources of multi-actors for value co-creation.
Contribution: The study of value co-creation in social network analysis represents an interesting gap and is highly essential for designing effective service system to enhance the goal of value co-creation. The paper contributes by illustrating (a) features of value co-creation in networks (b) empirical evidence of how strength of relationships of actors enhance resource integration in networks
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