1,378 research outputs found
Effects of OMMT on the aging behaviors of halogen-antimony flame-retarded LGFPA6 composites: Flammability and thermal degradation kinetics
After a long-term thermo-oxidative exposure, compared to the long-glass-fiber reinforced polyamide 6 composite containing halogen-antimony flame retardants (FR/LGFPA6), substitution of a certain content of flame retardants with organo-modified montmorillonite (OMMT) was found to positively affect the FR/LGFPA6 composite in some cases (i.e. flammability and thermal degradation kinetics). The aged OMMT/FR/LGFPA6 composite not only was less flammable but also behaved better in the formation of char residues. All the calculated apparent activation energy obtained by the methods of Friedman, Flynn-Wall-Ozawa and Coats- Redfern in a dynamic measurement showed an obvious increase for the OMMT/FR/LGFPA6 composite after aging, a theoretical evidence for its improved flame retardancy
Large-scale and controllable synthesis of metal-free nitrogen-doped carbon nanofibers and nanocoils over water-soluble Na2CO3
Prevalence and effects of emphysema in never-smokers with rheumatoid arthritis interstitial lung disease
AIMS: Autoimmune conditions such as rheumatoid arthritis-related interstitial lung disease (RA-ILD) have been linked to the existence of emphysema in never-smokers. We aimed to quantify emphysema prevalence in RA-ILD never-smokers and investigate whether combined pulmonary fibrosis and emphysema (CPFE) results in a worsened prognosis independent of baseline disease extent. METHODS: RA-ILD patients presenting to the Royal Brompton Hospital (n=90) and Asan Medical Center (n=155) had CT's evaluated for a definite usual interstitial pneumonia (UIP) pattern, and visual extents of emphysema and ILD. RESULTS: Emphysema, identified in 31/116 (27%) RA-ILD never-smokers, was associated with obstructive functional indices and conformed to a CPFE phenotype: disproportionate reduction in gas transfer (DLco), relative preservation of lung volumes. Using multivariate logistic regression, adjusted for patient age, gender and ILD extent, emphysema presence independently associated with a CT-UIP pattern in never-smokers (0.009) and smokers (0.02). On multivariate Cox analysis, following adjustment for patient age, gender, DLco, and a CT-UIP pattern, emphysema presence (representing the CPFE phenotype) independently associated with mortality in never-smokers (p=0.04) and smokers (p<0.05). CONCLUSION: 27% of RA-ILD never-smokers demonstrate emphysema on CT. Emphysema presence in never-smokers independently associates with a definite CT-UIP pattern and a worsened outcome following adjustment for baseline disease severity
Strongly Secure Authenticated Key Exchange from Supersingular Isogenies
This paper aims to address the open problem, namely, to find new techniques to design and prove security of supersingular isogeny-based authenticated key exchange (AKE) protocols against the widest possible adversarial attacks, raised by Galbraith in 2018. Concretely, we present two AKEs based on a double-key PKE in the supersingular isogeny setting secure in the sense of CK, one of the strongest security models for AKE. Our contributions are summarised as follows. Firstly, we propose a strong secure PKE,
, based on SI-DDH assumption. By applying modified Fujisaki-Okamoto transformation, we obtain a secure KEM, . Secondly, we propose a two-pass AKE, , based on SI-DDH assumption, using as a building block. Thirdly, we present a modified version of that is secure against leakage under the 1-Oracle SI-DH assumption. Using the modified as a building block, we then propose a three-pass AKE, , based on 1-Oracle SI-DH assumption. Finally, we prove that both and are CK secure in the random oracle model and supports arbitrary registration. We also provide an implementation to illustrate the efficiency of our schemes.
Our schemes compare favourably against existing isogeny-based AKEs. To the best of our knowledge, they are the first of its kind to offer security against arbitrary registration, wPFS, KCI and MEX simultaneously. Regarding efficiency, our schemes outperform existing schemes in terms of bandwidth as well as CPU cycle count
Computational Validation of Injection Molding Tooling by Additive Layer Manufacture to Produce EPDM Exterior Automotive Seals
During the design and development of ethylene propylene diene monomer (EPDM) exterior automotive seals, prototype components can only manufactured through production tooling platforms by either injection molding or extrusion. Consequently, tooling is expensive and has long lead times. This paper investigates whether additive layer manufacture is a viable method for producing tooling used in injection molding of exterior automotive seals in EPDM. Specifically, a novel rapid tooling is a method that combines additive layer manufacture (ALM) with epoxy reinforcement. Computational validation is performed whereby the mechanical properties of the tool are evaluated. The research has concluded that the novel tooling configuration would be suitable for prototyping purposes which would drastically reduce both costly and environmentally detrimental pre-manufacturing processes. This work has laid the foundations to implement rapid tooling technology to the injection molding of prototype EPDM parts
Regional disparities and productivity in China: evidence from manufacturing micro data
In this paper we first estimate firm-specific total factor productivities within 2-digit manufacturing industries using a semi-parametric algorithm and micro data for the period 2000–2007. Next, to characterize regional disparities in China we compute aggregate productivity by the categories of three regional typologies, based on population density, coastal-inland, and rural-urban criteria. We analyse the productivity differentials across the categories of the typologies by decomposing regional productivity level and growth into productivity effect and industry composition effect. We find clear evidence of regional convergence. Besides density of economic activity, recent policy and structural factors seem to affect regional productivity level and growth differentials
Reliability sensitivity analysis of geotechnical monitoring variables using Bayesian updating
A Comprehensive Survey of Data Mining-based Fraud Detection Research
This survey paper categorises, compares, and summarises from almost all
published technical and review articles in automated fraud detection within the
last 10 years. It defines the professional fraudster, formalises the main types
and subtypes of known fraud, and presents the nature of data evidence collected
within affected industries. Within the business context of mining the data to
achieve higher cost savings, this research presents methods and techniques
together with their problems. Compared to all related reviews on fraud
detection, this survey covers much more technical articles and is the only one,
to the best of our knowledge, which proposes alternative data and solutions
from related domains.Comment: 14 page
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