425 research outputs found
Capacitive Deionization for Selective Extraction of Lithium from Aqueous Solutions
The paper deals with extraction of lithium by means of two capacitive deionization systems: one composed of lithium selective electrode and second with electrode wrapped with Li-selective membrane. In the case of the first system, hybrid electrodes where obtained by mixing λ-MnO2sorbent with activated carbon .The best Li-capacity was determined for electrode with 20 wt.-% of manganese oxide. For larger amounts of λ-MnO2 the electrode capacity decreased significantly. The second system was composed of carbon electrodes wrapped with ion-exchange membranes. The lithium selective membranes were synthesized by plasma induced interpolymerization of (meth)acrylic monomersinpores of Celgard 2400 support. Two functional monomers, poly(di(ethylene glycol)methyl ether methacrylate) and poly(glycidylmethacylate modified with hydroxymethyl-12-crown-4) were copolymerized with acrylic acid. It was found that the extraction of lithium chloride was the best for membrane caring copolymers of acrylic acid and glycidyl methacrylate modified with crown ether, andit was better than for membranes with sole poly(acrylic acid)
Quantitative Risk-Based Analysis for Military Counterterrorism Systems
The article of record as published may be found at http://dx.doi.org/10.1002/sysThis paper presents a realistic and practical approach to quantitatively assess the risk-reduction
capabilities of military counterterrorism systems in terms of damage cost and casualty
figures. The comparison of alternatives is thereby based on absolute quantities rather than
an aggregated utility or value provided by multicriteria decision analysis methods. The key
elements of the approach are (1) the use of decision-attack event trees for modeling and
analyzing scenarios, (2) a portfolio model approach for analyzing multiple threats, and (3) the
quantitative probabilistic risk assessment matrix for communicating the results. Decision-attack
event trees are especially appropriate for modeling and analyzing terrorist attacks where
the sequence of events and outcomes are time-sensitive. The actions of the attackers and the
defenders are modeled as decisions and the outcomes are modeled as probabilistic events.
The quantitative probabilistic risk assessment matrix provides information about the range
of the possible outcomes while retaining the simplicity of the classic safety risk assessment
matrix based on Mil-Std-882D. It therefore provides a simple and reliable tool for comparing
alternatives on the basis of risk including confidence levels rather than single point estimates.
This additional valuable information requires minimal additional effort. The proposed approach
is illustrated using a simplified but realistic model of a destroyer operating in inland
restricted waters. The complex problem of choosing a robust counterterrorism protection
system against multiple terrorist threats is analyzed by introducing a surrogate multi-threat
portfolio. The associated risk profile provides a practical approach for assessing the robustness
of different counterterrorism systems against plausible terrorist threats. The paper documents the analysis for a hypothetical case of three potential threats.This work was performed as part of the Naval Postgraduate School institutionally funded research
Electro-driven materials and processes for lithium recovery—A review
The mass production of lithium-ion batteries and lithium-rich e-products that are required for electric vehicles, energy storage devices, and cloud-connected electronics is driving an unprecedented demand for lithium resources. Current lithium production technologies, in which extraction and purification are typically achieved by hydrometallurgical routes, possess strong environmental impact but are also energy-intensive and require extensive operational capabilities. The emergence of selective membrane materials and associated electro-processes offers an avenue to reduce these energy and cost penalties and create more sustainable lithium production approaches. In this review, lithium recovery technologies are discussed considering the origin of the lithium, which can be primary sources such as minerals and brines or e-waste sources generated from recycling of batteries and other e-products. The relevance of electro-membrane processes for selective lithium recovery is discussed as well as the potential and shortfalls of current electro-membrane methods
Negative emotions boost users activity at BBC Forum
We present an empirical study of user activity in online BBC discussion
forums, measured by the number of posts written by individual debaters and the
average sentiment of these posts. Nearly 2.5 million posts from over 18
thousand users were investigated. Scale free distributions were observed for
activity in individual discussion threads as well as for overall activity. The
number of unique users in a thread normalized by the thread length decays with
thread length, suggesting that thread life is sustained by mutual discussions
rather than by independent comments. Automatic sentiment analysis shows that
most posts contain negative emotions and the most active users in individual
threads express predominantly negative sentiments. It follows that the average
emotion of longer threads is more negative and that threads can be sustained by
negative comments. An agent based computer simulation model has been used to
reproduce several essential characteristics of the analyzed system. The model
stresses the role of discussions between users, especially emotionally laden
quarrels between supporters of opposite opinions, and represents many observed
statistics of the forum.Comment: 29 pages, 6 figure
Bloggers Behavior and Emergent Communities in Blog Space
Interactions between users in cyberspace may lead to phenomena different from
those observed in common social networks. Here we analyse large data sets about
users and Blogs which they write and comment, mapped onto a bipartite graph. In
such enlarged Blog space we trace user activity over time, which results in
robust temporal patterns of user--Blog behavior and the emergence of
communities. With the spectral methods applied to the projection on weighted
user network we detect clusters of users related to their common interests and
habits. Our results suggest that different mechanisms may play the role in the
case of very popular Blogs. Our analysis makes a suitable basis for theoretical
modeling of the evolution of cyber communities and for practical study of the
data, in particular for an efficient search of interesting Blog clusters and
further retrieval of their contents by text analysis
Collective emotions online and their influence on community life
E-communities, social groups interacting online, have recently become an
object of interdisciplinary research. As with face-to-face meetings, Internet
exchanges may not only include factual information but also emotional
information - how participants feel about the subject discussed or other group
members. Emotions are known to be important in affecting interaction partners
in offline communication in many ways. Could emotions in Internet exchanges
affect others and systematically influence quantitative and qualitative aspects
of the trajectory of e-communities? The development of automatic sentiment
analysis has made large scale emotion detection and analysis possible using
text messages collected from the web. It is not clear if emotions in
e-communities primarily derive from individual group members' personalities or
if they result from intra-group interactions, and whether they influence group
activities. We show the collective character of affective phenomena on a large
scale as observed in 4 million posts downloaded from Blogs, Digg and BBC
forums. To test whether the emotions of a community member may influence the
emotions of others, posts were grouped into clusters of messages with similar
emotional valences. The frequency of long clusters was much higher than it
would be if emotions occurred at random. Distributions for cluster lengths can
be explained by preferential processes because conditional probabilities for
consecutive messages grow as a power law with cluster length. For BBC forum
threads, average discussion lengths were higher for larger values of absolute
average emotional valence in the first ten comments and the average amount of
emotion in messages fell during discussions. Our results prove that collective
emotional states can be created and modulated via Internet communication and
that emotional expressiveness is the fuel that sustains some e-communities.Comment: 23 pages including Supporting Information, accepted to PLoS ON
Reasons for low utilisation of public facilities among households with hypertension: analysis of a population-based survey in India.
INTRODUCTION: In India, for most patients, primary healthcare remains the intended entry point for the management of non-communicable disease risk factors. The extent and determinants of non-utilisation of public primary care among households with hypertension are not well examined. We explored health facility utilisation patterns and reasons for non-utilisation of public facilities in 21 states and union territories in India, with a focus on hypertension. METHODS: We used data from the 2012-2013 District Level Household and Facility Survey. We examined the self-reported usual source of care for all households, households with hypertension and─to understand multimorbidity for those with hypertension─households with hypertension and diabetes. Hypertension was defined by self-reported diagnosis or measurement of systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg. Diabetes was defined by self-reported diagnosis or fasting blood glucose level ≥ 7.0 mmol/L or non-fasting blood glucose level ≥ 11.1 mmol/L. We assessed facility utilisation choice and reasons for non-utilisation of public facilities by household with the presence of hypertension alone and hypertension with diabetes. RESULTS: In 336 305 households, 37.6% (N=126 597) had at least one household member with hypertension, while 15.9% (N=53 385) had members with hypertension and diabetes. 20.0% of households sought care at public primary clinics, 29.9% at public hospitals and 48.3% at private facilities. Choice of private facilities increased with the burden of disease. Households with hypertension only and hypertension and diabetes cited quality reasons for non-utilisation of public facilities more than households without hypertension. CONCLUSION: Households, particularly those with hypertension, chose private over public primary facilities for usual care. Quality of care was an important determinant of facility choice in households with hypertension and diabetes. With the increase in hypertension and cardiovascular disease in India, quality of public primary healthcare must be addressed for current policy to become reality
A phase 1 clinical trial of vorinostat in combination with decitabine in patients with acute myeloid leukaemia or myelodysplastic syndrome
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108599/1/bjh13016.pd
Completely integrable models of non-linear optics
The models of the non-linear optics in which solitons were appeared are
considered. These models are of paramount importance in studies of non-linear
wave phenomena. The classical examples of phenomena of this kind are the
self-focusing, self-induced transparency, and parametric interaction of three
waves. At the present time there are a number of the theories based on
completely integrable systems of equations, which are both generations of the
original known models and new ones. The modified Korteweg-de Vries equation,
the non- linear Schrodinger equation, the derivative non-linear Schrodinger
equation, Sine-Gordon equation, the reduced Maxwell-Bloch equation, Hirota
equation, the principal chiral field equations, and the equations of massive
Thirring model are gradually putting together a list of soliton equations,
which are usually to be found in non-linear optics theory.Comment: Latex, 17 pages, no figures, submitted to Pramana
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The Clinical and Economic Burden of Antibiotic Use in Pediatric Patients with Varicella Infection: a Retrospective Cohort Analysis of Real-World Data in England.
BACKGROUND: Varicella is a highly infectious disease, particularly affecting children, that can lead to complications requiring antibiotics or hospitalization. Antibiotic use for varicella management is poorly documented. This study assessed antibiotic use for varicella and its complications in a pediatric population in England. METHODS: Data were drawn from medical records in the Clinical Practice Research Datalink and Hospital Episode Statistics datasets. Patients <18 years old diagnosed with varicella during 2014-2018 with 3-month follow-up available were included. We described varicella-related complications, medication use, healthcare resource utilization, and costs from diagnosis until 3-month post-diagnosis. RESULTS: We identified 114,578 children with a primary varicella diagnosis. 7.7% (n = 8,814) had a varicella-related complication, the most common being ear, nose, and throat related (37.1%, n = 3,271). In all, 25.9% (n = 29,706/114,578) were prescribed antibiotics. A higher proportion of patients with complications than those without complications were prescribed antibiotics (64.3%, n = 5,668/8,814 vs. 22.7%, n = 24,038/105,764). Mean annualized varicella-related costs were £2,231,481 for the study cohort. Overall, antibiotic prescriptions cost ∼£262,007. CONCLUSIONS: This study highlights high antibiotic use and healthcare resource utilization associated with varicella management, particularly in patients with complications. A national varicella vaccination program in England may reduce varicella burden and related complications, medication use, and costs
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