3,186 research outputs found
Boron Nitride Nanosheets for Metal Protection
Although the high impermeability of graphene makes it an excellent barrier to
inhibit metal oxidation and corrosion, graphene can form a galvanic cell with
the underlying metal that promotes corrosion of the metal in the long term.
Boron nitride (BN) nanosheets which have a similar impermeability could be a
better choice as protective barrier, because they are more thermally and
chemically stable than graphene and, more importantly, do not cause galvanic
corrosion due to their electrical insulation. In this study, the performance of
commercially available BN nanosheets grown by chemical vapor deposition as a
protective coating on metal has been investigated. The heating of the copper
foil covered with the BN nanosheet at 250 {\deg}C in air over 100 h results in
dramatically less oxidation than the bare copper foil heated for 2 h under the
same conditions. The electrochemical analyses reveal that the BN nanosheet
coating can increase open circuit potential and possibly reduce oxidation of
the underlying copper foil in sodium chloride solution. These results indicate
that BN nanosheets are a good candidate for oxidation and corrosion protection,
although conductive atomic force microscopy analyses show that the
effectiveness of the protection relies on the quality of BN nanosheets.Comment: With Supporting Informatio
Implications of the Method of Construction of UK Number Plates for Infrared Reflectance and Camera Settings on ANPR System
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper considers the implications of two aspects of number plates firstly the varied manufacturing process in the physical construction of vehicle number plates that might affect the reflectance characteristics and secondly the ANPR camera settings that affect the night time capture performance. These parameters have an effect on the overall performance of an Automatic Number Plate Recognition system. A set of controlled experiments on number plates is carried out to establish variation in the retroreflective response to illumination as well as field analysis on real world number plates
A win-win for legume mixtures
The inter-relationship between food production and biodiversity is now well established. The ecosystem services provided by the organisms within the environment include, for example, nutrient cycling, pest regulation and pollination, to name but a few. However, perhaps the greatest challenge now facing agricultural production is to find ways of enhancing these ecosystem services, while at the same time increasing food production – particularly in light of food security issues. A range of farm and landscape management options include ‘setting aside’ land for wildlife. However, some proponents argue that such land should be used for food production. While the debate continues, there is no doubt that a large body of scientific evidence from the last three decades highlights the wildlife benefits of organic farming. This article will describe how the Legume LINK project has identified a win-win system for biodiversity conservation and increased productivity through legume-base fertility building. Although this project has focused on organic farming systems, it is of direct relevance to non-organic production, particularly with the increasing interest in legumes across the industry
e-EVN radio detection of Aql X-1 in outburst
The neutron star X-ray binary Aql X-1 is currently in outburst. Using the European VLBI Network (e-EVN) we observed Aql X-1 at 5 GHz in two time-slots: 2013 June 18 between 19:48 - 20:36 UT (MJD 56461.825 - 56461.858), and 2013 June 19 between 02:53 - 05:54 UT (MJD 56462.120 - 56462.246). The two datasets were combined together and then calibrated
Decision-analytic cost-effectiveness model to compare prostate cryotherapy to androgen deprivation therapy for treatment of radiation recurrent prostate cancer
Objective: To determine the cost-effectiveness of salvage cryotherapy (SC) in men with radiation recurrent prostate cancer (RRPC).
Design: Cost-utility analysis using decision analytic modelling by a Markov model.
Setting and methods: Compared SC and androgen deprivation therapy (ADT) in a cohort of patients with RRPC (biopsy proven local recurrence, no evidence of metastatic disease). A literature review captured published data to inform the decision model, and resource use data were from the Scottish Prostate Cryotherapy Service. The model was run in monthly cycles for RRPC men, mean age of 70 years. The model was run over the patient lifetime, to assess changes in patient health states and the associated quality of life, survival and cost impacts. Results are reported in terms of the discounted incremental costs and discounted incremental quality-adjusted life years (QALYs) gained between the 2 alternative interventions. Probabilistic sensitivity analysis used a 10 000 iteration Monte Carlo simulation.
Results: SC has a high upfront treatment cost, but delays the ongoing monthly cost of ADT. SC is the dominant strategy over the patient lifetime; it is more effective with an incremental 0.56 QALY gain (95% CI 0.28 to 0.87), and less costly with a reduced lifetime cost of £29 719 (€37 619) (95% CI −51 985 to −9243). For a ceiling ratio of £30 000, SC has a 100% probability to be cost-effective. The cost neutral point was at 3.5 years, when the upfront cost of SC (plus any subsequent cumulative cost of side effects and ADT) equates the cumulative cost in the ADT arm. Limitations of our model may arise from its insensitivity to parameter or structural uncertainty.
Conclusions: The platform for SC versus ADT cost-effective analysis can be employed to evaluate other treatment modalities or strategies in RRPC. SC is the dominant strategy, costing less over a patient's lifetime with improvements in QALYs
Universal Reconfigurable Translator Module (URTM) Final Report
This report describes the Universal Reconfigurable Translation Module, or URTM. The URTM was developed by Sigma Space Corporation for NASA in order to translate specific serial protocols, both logically and physically. At present, the prototype configuration has targeted MIL-STD-1553B (RT and BC), IEEE 1394b (Firewire), and ECSS-E-50-12A (SpaceWire). The objectives of this program were to study the feasibility of a configurable URTM to translate serial link data as might be used in a space-flight mission and to design, develop, document, and deliver an engineering prototype model of the URTM with a path to spaceflight. By simply connecting two of the three Physical Interface Modules (PIM) on either end of the RPTM (Reconfigurable Protocol Translator Module), the URTM then self configures via a library of interface translation functions, thereby allowing the two data links to communicate seamlessly
Tuning Promoter Strength through RNA Polymerase Binding Site Design in Escherichia coli
One of the paramount goals of synthetic biology is to have the ability to tune transcriptional networks to targeted levels of expression at will. As a step in that direction, we have constructed a set of 18 unique binding sites for E. coli RNA Polymerase (RNAP) σ^(70) holoenzyme, designed using a model of sequence-dependent binding energy combined with a thermodynamic model of transcription to produce a targeted level of gene expression. This promoter set allows us to determine the correspondence between the absolute numbers of mRNA molecules or protein products and the predicted promoter binding energies measured in K_(B)T energy units. These binding sites adhere on average to the predicted level of gene expression over orders of magnitude in constitutive gene expression, to within a factor of in both protein and mRNA copy number. With these promoters in hand, we then place them under the regulatory control of a bacterial repressor and show that again there is a strict correspondence between the measured and predicted levels of expression, demonstrating the transferability of the promoters to an alternate regulatory context. In particular, our thermodynamic model predicts the expression from our promoters under a range of repressor concentrations between several per cell up to over 100 per cell. After correcting the predicted polymerase binding strength using the data from the unregulated promoter, the thermodynamic model accurately predicts the expression for the simple repression strains to within 30%. Demonstration of modular promoter design, where parts of the circuit (such as RNAP/TF binding strength and transcription factor copy number) can be independently chosen from a stock list and combined to give a predictable result, has important implications as an engineering tool for use in synthetic biology
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