1,156 research outputs found
Self-Organized Ni Nanocrystal Embedded in BaTiO3 Epitaxial Film
Ni nanocrystals (NCs) were embedded in BaTiO3 epitaxial films using the laser molecular beam epitaxy. The processes involving the self-organization of Ni NCs and the epitaxial growth of BaTiO3 were discussed. With the in situ monitoring of reflection high-energy electron diffraction, the nanocomposite films were engineered controllably by the fine alternation of the self-organization of Ni NCs and the epitaxial growth of BaTiO3. The transmission electron microscopy and the X-ray diffraction characterization confirmed that the composite film consists of the Ni NCs layers alternating with the (001)/(100)-oriented epitaxial BaTiO3 separation layers
A knowledge-based design advisory system for collaborative design for micromanufacturing
The manufacture of microproducts differs from that of conventional products in many ways, not only in the sizes, but also in issues concerning the effects of material properties, tools, and manufacturing equipment. There was a need for a new design methodology and associated design tools to aid designers in assessing the design of their microproducts by considering new micromanufacturing capabilities and constraints. A knowledge-based design advisory system (DAS) was, therefore, developed in MASMICRO in which the knowledge-based system with dedicated assessment modules and knowledge representatives based on the ontology was created to implement the distributed design and manufacturing assessment for micromanufacturing. The modules address the assessment on geometrical features relating to manufacturability, manufacturing processes, selection of materials, tools, and machines, as well as manufacturing cost. The Microsoft C# programming language, ASP.NET web technology, Prolog, and Microsoft Access database were used to develop the DAS. The test on the DAS prototype system was found to provide an increase of design efficiency due to more efficient use of design and manufacturing knowledge and afforded a web-based collaborative design environment
Resonances in and
A partial wave analysis is presented of and
from a sample of 58M events in the BES II detector. The
is observed clearly in both sets of data, and parameters of the
Flatt\' e formula are determined accurately: (stat)
(syst) MeV/c, MeV/c, . The data also exhibit a strong peak
centred at MeV/c. It may be fitted with and a
dominant signal made from interfering with a smaller
component. There is evidence that the signal is
resonant, from interference with . There is also a state in with MeV/c and
MeV/c; spin 0 is preferred over spin 2. This state, , is
distinct from . The data contain a strong peak due to
. A shoulder on its upper side may be fitted by interference
between and .Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.
First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)
The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the
first time using a sample of 5.8X10^7 J/\psi events collected by the BESII
detector. The product branching fractions are determined to be B(J/\psi-->gamma
eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+-
0.23)X10^{-4}, and (J/\psi-->gamma eta_c)*
B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper
limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma
eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence
level.Comment: 11 pages, 4 figure
Quantitative analysis of lung elastic fibers in idiopathic pleuroparenchymal fibroelastosis (IPPFE): comparison of clinical, radiological, and pathological findings with those of idiopathic pulmonary fibrosis (IPF)
Comparison of a new transcutaneous bilirubinometer (Bilimed®) with serum bilirubin measurements in preterm and full-term infants
<p>Abstract</p> <p>Background</p> <p>The gold standard to assess hyperbilirubinemia in neonates remains the serum bilirubin measurement. Unfortunately, this is invasive, painful, and costly. Bilimed<sup>®</sup>, a new transcutaneous bilirubinometer, suggests more accuracy compared to the existing non-invasive bilirubinometers because of its new technology. It furthermore takes into account different skin colours. No contact with the skin is needed during measurement, no additional material costs occur. Our aim was to assess the agreement between the Bilimed<sup>® </sup>and serum bilirubin in preterm and term infants of different skin colours.</p> <p>Methods</p> <p>The transcutaneous bilirubin measurements were performed on the infant's sternum and serum bilirubin was determined simultaneously. The agreement between both methods was assessed by Pearson's correlation and by Bland-Altman analysis.</p> <p>Results</p> <p>A total of 117 measurement cycles were performed in 99 term infants (group1), further 47 measurements in 38 preterm infants born between 34 - 36 6/7 gestational weeks (group 2), and finally 21 measurements in 13 preterm infants born between 28 - 33 6/7 gestational weeks (group 3). The mean deviation and variability (+/- 2SD) of the transcutaneous from serum bilirubin were: -14 (+/- 144) μmol/l; -0.82 (+/- 8.4) mg/dl in group 1, +16 (+/- 91) μmol/l;+0.93(+/- 5.3) mg/dl in group 2 and -8 (+/- 76) μmol/l; -0.47 (+/- 4.4) mg/dl in group 3. These limits of agreement are too wide to be acceptable in a clinical setting. Moreover, there was to be a trend towards less good agreement with increasing bilirubin values.</p> <p>Conclusion</p> <p>Despite its new technology the Bilimed<sup>® </sup>has no advantages, and more specifically no better agreement not only in term and near-term Caucasian infants, but also in non-Caucasian and more premature infants.</p
A novel investigation into the application of non-destructive evaluation for vibration assessment and analysis of in-service pipes
Flow induced vibrations that are close to resonance frequencies are a major
problem in all oil and gas processing industries, so all piping systems require
regular condition monitoring and inspection to assess changes in their dynamic
characteristics and structural integrity in order to prevent catastrophic failures.
One of the main causes of pipe failure is weak support causing low frequency
high amplitude flow-induced vibration. This causes wear and tear, especially
near joints due to their dissimilar stiffness resulting in fatigue failure of joints
caused by vibration-induced high cyclic stress. Other contributing factors in pipe
failure are poor or inadequate design, poor workmanship during installation or
maintenance and inadequate or weak and flexible support. These pipes are
usually required to work non-stop for 24 hours a day 7 days a week for weeks,
months or years at a time. Regular monitoring and in-service dynamic analysis
should ensure continuous and safe operation. A novel method of non-destructive
testing and evaluation of these pipes, while in service, is proposed in this paper.
This technique will enable early detection and identification of the root causes of
any impending failure due to excess vibration as a result of cyclic force induced
by the flow. The method pinpoints the location of the impending failure prior to
condition-based maintenance procedures. The technique relies on the combined
application of Operating Deflection Shapes (ODS) analysis and computational
mechanics utilizing Finite Element Analysis (FEA), i.e. linear elastic stress
analysis. Any structural modification to the pipes and their supports can then be
applied virtually and their effects on the system can be analysed. The effect on
vibration levels is assessed and verified. The effect of any change in the forces
corresponding to changes in the Differential Pressure (DP) at constant flow rate
through the pipes can then be estimated. It was concluded that maintaining the
differential pressure above some “critical” threshold ensures the pipe operates
under the allowable dynamic stress for a theoretically “indefinite” life cycle
Membranes by the Numbers
Many of the most important processes in cells take place on and across
membranes. With the rise of an impressive array of powerful quantitative
methods for characterizing these membranes, it is an opportune time to reflect
on the structure and function of membranes from the point of view of biological
numeracy. To that end, in this article, I review the quantitative parameters
that characterize the mechanical, electrical and transport properties of
membranes and carry out a number of corresponding order of magnitude estimates
that help us understand the values of those parameters.Comment: 27 pages, 12 figure
Improved representation of the diurnal variation of warm season precipitation by an atmospheric general circulation model at a 10 km horizontal resolution
This study investigates the diurnal variation of the warm season precipitation simulated by the Goddard Earth Observing System version 5 atmospheric general circulation model for 2??years (2005???2006) at a horizontal resolution of 10??km. The simulation was validated with the satellite-derived Tropical Rainfall Measuring Mission (TRMM) 3B42 precipitation data and the Modern-Era Retrospective analysis for Research and Applications atmospheric reanalysis for atmospheric winds and moisture. The simulation is compared with the coarse-resolution run in 50??km to examine the impacts driven by resolution change. Overall, the 10??km model tends to reproduce the important features of the observed diurnal variation, such as the amplitude and phase at which precipitation peaks in the evening on land and in the morning over the ocean, despite an excessive amplitude bias over land. The model also reproduces the realistic propagation patterns of precipitation in the vicinity of ocean coasts and major mountains. The regional characteristics of the diurnal precipitation over two regions, the Bay of Bengal and the Great Plains in North America, are examined in detail, where the observed diurnal cycle exhibits a systematic transition in the peak phase due to the development and propagation of regional-scale convective systems. The model is able to reproduce this pattern as well as the diurnal variation of low-level wind and moisture convergence; however, it is less effective at representing the nocturnal peak of precipitation over the Great Plains. The model results suggest that increasing the horizontal resolution of the model to 10??km substantially improves the representation of the diurnal precipitation cycle. However, intrinsic model deficiencies in topographical precipitation and the accurate representation of mesoscale convective systems remain a challenge
Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.
BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721
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