2,197 research outputs found
Recent Techniques in Design and Implementation of Microwave Planar Filters
This paper details the techniques and initiatives made recently for improved response and simultaneous development of microwave planar filters. Although the objective of all the techniques is to design low cost filters with reduced dimensions, compact size with better frequency response, the methodological approaches are quite variant. The paper has gone through extensive analysis of all these techniques, their concept and design procedures
Improved impact performance of marine sandwich panels using through-thickness reinforcement: Experimental results
This paper presents results from a test developed to simulate the water impact
(slamming) loading of sandwich boat structures. A weighted elastomer ball is
dropped from increasing heights onto rigidly supported panels until damage is
detected. Results from this test indicate that honeycomb core sandwich panels,
the most widely used material for racing yacht hulls, start to damage due to
core crushing at impact energies around 550 J. Sandwich panels of the same areal
weight and with the same carbon/epoxy facings but using a novel foam core
reinforced in the thickness direction with pultruded carbon fibre pins, do not
show signs of damage until above 1200 J impact energy. This suggests that these
will offer significantly improved resistance to wave impact. Quasi-static test
results cannot be used to predict impact resistance here as the crush strength
of the pinned foam is more sensitive to loading rate than that of the honeycomb
core
Magnetic order in the two-dimensional metal-organic framework manganese pyrazinecarboxylate with Mn-Mn dimers
The magnetic properties of [Mn(pyrazinecarboxylate)2]n (Mn-pyrazine),
empirical formula C10H6MnN4O4, are investigated through susceptibility, heat
capacity and neutron scattering measurements. The structure of Mn-pyrazine
consists of Mn-Mn dimers linked on a distorted 2D hexagonal structure. The weak
out of plane interactions create a quasi-2D magnetic material within the larger
three dimensional metal organic framework (MOF) structure. We show that this
material undergoes a two stage magnetic transition, related to the low
dimensionality of the Mn lattice. First at 5 K, which is assigned to the
initial development of short range order in the 2D layers. This is followed by
long range order at 3.3 K. Applied field measurements reveal the potential to
induce magnetic transitions in moderately small fields of 2 T. Neutron powder
diffraction enabled the determination of a unique magnetic space group P21'/c
(#14.77) at 1.5 K. This magnetic structure consists of antiferromagnetically
coupled Mn-Mn dimers with spins principally along the out of plane a-axis
Creep strength behavior of boron added P91 steel and its weld in the temperature range of 600–650 degree C
One of the promising ways for mitigation of Type IV cracking – a failure by cracking at the
intercritical /fine grained heat affected zone, a life limiting problem in advanced 9–12 Cr ferritic
steel weld like that of P91 is through modification of alloy composition by addition of boron.
Addition of boron was observed to improve the microstructure at the weld zone and hence the
creep strength. In the present work, boron (100 ppm with controlled nitrogen) added P91 steel
after normalizing at 1050C and 1150C and tempered at 760C were studied for the creep
behavior in the base metal and welded condition in the temperature range of 600–650C. Creep
strength was characterized in terms of stress and temperature dependence of creep rate and
rupture time. Weld creep life was reduced compared to the base metal with rupture occurring at
the ICHAZ (Type IV crack). However at longer time (at lower stress levels) exposure creep
crack moves from weld metal to HAZ (Type II crack). Rupture life was found to superior for the
base and weld in the boron containing steel when higher normalizing temperature is used.
Estimation of 10 5 h was attempted based on short term rupture data available and weld strength
factors were calculated. Observed values are better for P91BH condition than the values for
P91BL condition as well as those available for P91 in open literatur
The values and principles underpinning community engagement approaches to tackling antimicrobial resistance (AMR)
This paper presents seven values underpinning the application of Community Engagement (CE) approaches to the One Health challenge of antimicrobial resistance (AMR) developed during an international workshop in June 2019. We define a value as a quality or standard which a CE project is aiming for, whilst a principle is an objective which underpins the value and facilitates its achievement. The values of Clarity, Creativity, (being) Evidence-led, Equity, Interdisciplinarity, Sustainability and Flexibility were identified by a network of 40 researchers and practitioners who utilise CE approaches to tackle complex One Health challenges including, but not limited to, AMR. We present our understanding of these seven values and their underlying principles as a flexible tool designed to support stakeholders within CE for AMR projects. We include practical guidance on working toward each value, plus case studies of the values in action within existing AMR interventions. Finally, we consider the extent to which CE approaches are appropriate to tackle AMR challenges. We reflect on these in relation to the tool, and current literature for both CE and AMR research. Authors and co-producers anticipate this tool being used to scene-set, road map and trouble shoot the development, implementation, and evaluation of CE projects to address AMR and other One Health challenges. However, the tool is not prescriptive but responsive to the context and needs of the community, opening opportunity to build a truly collaborative and community-centred approach to AMR research
A Taxonomy of Causality-Based Biological Properties
We formally characterize a set of causality-based properties of metabolic
networks. This set of properties aims at making precise several notions on the
production of metabolites, which are familiar in the biologists' terminology.
From a theoretical point of view, biochemical reactions are abstractly
represented as causal implications and the produced metabolites as causal
consequences of the implication representing the corresponding reaction. The
fact that a reactant is produced is represented by means of the chain of
reactions that have made it exist. Such representation abstracts away from
quantities, stoichiometric and thermodynamic parameters and constitutes the
basis for the characterization of our properties. Moreover, we propose an
effective method for verifying our properties based on an abstract model of
system dynamics. This consists of a new abstract semantics for the system seen
as a concurrent network and expressed using the Chemical Ground Form calculus.
We illustrate an application of this framework to a portion of a real
metabolic pathway
The importance of providing counselling and financial support to patients receiving treatment for multi-drug resistant TB: Mixed method qualitative and pilot intervention studies
Background: People with multi-drug resistant tuberculosis (MDR-TB) in low-income countries face many problems during treatment, and cure rates are low. The purpose of the study was (a) to identify and document the problems experienced by people receiving care for MDR-TB, and how they cope when support is not provided, to inform development of strategies; (b) to estimate the effectiveness of two resultant strategies, counselling alone, and joint counselling and financial support, of increasing DOTS-plus treatment success under routine programme conditions. Methods. A mixed-method study comprising a formative qualitative study, pilot intervention study and explanatory qualitative study to better understand barriers to completion of treatment for MDR-TB. Participants were all people starting MDR-TB treatment in seven DOTS-plus centres in the Kathmandu Valley, Nepal during January to December 2008. The primary outcome measure was cure, as internationally defined. Results: MDR-TB treatment caused extreme social, financial and employment hardship. Most patients had to move house and leave their job, and reported major stigmatisation. They were concerned about the long-term effects of their disease, and feared infecting others. In the resultant pilot intervention study, the two strategies appeared to improve treatment outcomes: cure rates for those receiving counselling, combined support and no support were 85%, 76% and 67% respectively. Compared with no support, the (adjusted) risk ratios of cure for those receiving counselling and receiving combined support were 1.2 (95% CI 1.0 to 1.6) and 1.2 (95% CI 0.9 to 1.6) respectively. The explanatory study demonstrated that patients valued both forms of support. Conclusions: MDR-TB patients are extremely vulnerable to stigma and extreme financial hardship. Provision of counselling and financial support may not only reduce their vulnerability, but also increase cure rates. National Tuberculosis Programmes should consider incorporating financial support and counselling into MDR-TB care: costs are low, and benefits high, especially since costs to society of incomplete treatment and potential for incurable TB are extremely high
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Measurement of charged jet cross section in pp collisions at s =5.02 TeV
The cross section of jets reconstructed from charged particles is measured in the transverse momentum range of
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