221 research outputs found
The fans united will always be connected: building a practical DTN in a football stadium
Football stadia present a difficult environment for the deployment of digital services, due to their architectural design and the capacity problems from the numbers of fans. We present preliminary results from deploying an Android app building an ad hoc network amongst the attendees at matches at Brighton and Hove Albion's AMEX stadium, so as to share the available capacity and supply digital services to season
ticket holders. We describe the protocol, how we engaged our users in service design so that the app was attractive to use and the problems we encountered in using Android
Poly(acrylic acid) interpolymer complexation: use of a fluorescence time resolved anisotropy as a poly(acrylamide) probe
YesA low concentration poly(acrylamide) sensor has been developed
which uses the segmental mobility of another polymer probe with a
covalently attached fluorescent marker. Interpolymer complexation
with poly(acrylic acid) leads to reduced segmental mobility which can
be used to determine the concentration of polymer in solution. This
technique could be useful in detecting the runoff of polymer dispersants
and flocculants in fresh water supplies following water purification
processes.Funding for the research was kindly provided by the Engineering and Physical Sciences Research Council (EPSRC)
Highly-branched poly(N-isopropyl acrylamide)s with core-shell morphology below the lower critical solution temperature
YesHighly-branched poly(N-isopropyl acrylamide)s in water pass through coil-to-globule transitions. Using
calorimetry and the colour change of a solvatochromic dye within the polymer, we show that some
compositions have biphasic coreâshell morphologies, with globular cores and open coil shells. The two-phase
structure is favoured by increased branching and arises because the chain ends penetrate only to
a limited degree into the polymer coil
pH Responsive Highly Branched Poly(N-isopropylacrylamide) with Trihistidine or Acid Chain Ends
YesThermally responsive highly branched poly(N-isopropyl acrylamide)s (HB-PNIPAM) were prepared and end-functionalised
to give polymers with acid or trihistidine end groups. These polymers exhibit a broad coil-to-globule transition across a
wide temperature range which can be measured using covalently attached fluorescent tags. The acid chain ends provided
a material with a distinct change in solution behaviour at pH close to the pKa of the carboxylate group. At pH 11 this
polymer did not show a cloud point up to 50 °C but fluorescence measurements on the labelled polymers showed that a
coil to glubule transition did take place. The globular state, above the LCST, appeared to be more swollen if the end group
carried charge then when it was uncharged. A polymer with trihistidine and free carboxylate chain ends, which contained
multiple charges at various pH, did show LCSTs at all pH and the polymer globule was shown to be swollen at each pH
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UK-India Centre for Advanced Technology for Minimizing Indiscriminate Use of Antibiotics:"Exploring biology of antibiotic resistance and potential targets for early diagnosis and effective management of infectious diseasesâ
YesDuring January 15th â 17th, 2017 a group of scientists met, under the auspices of the UK-India Centre for Advanced Technology for Minimizing Indiscriminate Use of Antibiotics, to discuss the further developments and potential solutions to antimicrobial resistance. This was the third work shop under this funding stream held in Hyderabad. The presentations and outcomes of the workshop are released here. Key out comes included the need to address improved treatment and detection of TB, delivery of antimicrobial peptides, potential strategies for combating beta-lactam resistance.Medical Research Counci
A self-healable fluorescence active hydrogel based on ionic block copolymers prepared via ring opening polymerization and xanthate mediated RAFT polymerization
YesIn this work we report a facile method to prepare a fluorescence active self-healable hydrogel via incorporation of fluorescence responsive ionic block copolymers (BCPs). Ionic block copolymers were prepared via a combined effect of ring opening polymerization (ROP) of Δ-caprolactone and xanthate mediated reversible additionâfragmentation chain transfer (RAFT) polymerization. Here polycaprolactone (PCL) was modified with xanthate to prepare a PCL based macro-RAFT agent and then it was utilized to prepare block copolymers with cationic poly(2-(methacryloyloxy)ethyltrimethyl ammonium chloride) (PCL-b-PMTAC) and anionic poly(sodium 4-vinylbenzenesulfonate) (PCL-b-PSS). During the block formation, the cationic segments were randomly copolymerized with a trace amount of fluorescein O-acrylate (FA) (acceptor) whereas the anionic segments were randomly copolymerized with a trace amount of 9-anthryl methylmethacrylate (AMMA) (donor) to make both the segments fluorescent. The block copolymers form micelles in a DMFâ:âwater mixture (1â:â4 volume ratio). The ionic interaction of two BCPs was monitored via Förster resonance energy transfer (FRET) and zeta potential measurements. The oppositely charged BCPs were incorporated into a polyacrylamide (PAAm) based hydrogel that demonstrated self-healing behavior and is also highly fluorescent.IIT Kharagpur and MRC (MR/N501888/2
An experimental study into the effect of the pilot injection timing on the performance and emissions of a high-speed common-rail dual-fuel engine
Dual fuel technology has the potential to offer significant improvements in emissions of carbon dioxide from light-duty compression ignition engines. In these smaller capacity high speed engines, where the combustion event can be temporally shorter, the injection timing can have an important effect on the performance and emissions characteristics of the engine. This paper discusses the use of a 0.51-litre single-cylinder high speed direct injection diesel engine modified to achieve port directed gas injection. The effect of pilot diesel injection timing on dual fuel engine performance and emissions was investigated at engine speeds of 1500 and 2500 rpm and loads equivalent to 0.15, 0.3, 0.45 and 0.6 MPa gross indicated mean effective pressure, for a fixed gas substitution ratio (on an energy basis) of 50%. Furthermore, the effect of pilot injection quantity was investigated at a constant engine speed of 1500 rpm by completing a gaseous substitution sweep at the optimised injection timing for each load condition. The results identify the limits of single injection timing during dual fuel combustion and the gains in engine performance and stability that can be achieved through optimisation of the pilot injection timing. Furthermore, pilot injection timing and quantity were shown to have fundamental effects on the formation and emission of carbon monoxide, nitrogen oxide and total hydrocarbons. The potential for dual fuel combustion to achieve significant reductions in specific CO2 was also highlighted, with reductions of up to 30% being achieved at full load compared to the baseline diesel case
Poly(acrylic acid) interpolymer complexes
YesInterpolymer complex formation of poly(acrylic acid) with other macromolecules can occur via several mechanisms that vary depending on the pH. At low pH the protonated acid functional group can form bonds with both donor and acceptor moieties, resulting in desolvated structures consisting of two polymers. Complexes were formed in dilute solutions of PAA, functionalised with acenaphthylene, with a range of other polymers including: poly(NIPAM); poly(ethylene oxide) (PEO); poly(dimethylacrylamide) (PDMA); poly(diethyl acrylamide) (PDEAM) poly(vinyl alcohol) (PVA) and poly(vinyl pyrolidinone) (PVP). Fluorescence anisotropy was used to demonstrate complex formation in each case by monitoring the reductions in segmental motion of the chain as the complexes formed. Considerations of the molecular structures of the complexing moieties suggest that solvation energies and pKas play an important role in complex formation
Core (Polystyrene)âShell [Poly(glycerol monomethacrylate)] Particles
YesA set of water-swollen coreâshell particles was
synthesized by emulsion polymerization of a 1,3-dioxolane
functional monomer in water. After removal of the 1,3-
dioxolane group, the particlesâ shells were shown to swell in
aqueous media. Upon hydrolysis, the particles increased in size
from around 70 to 100â130 nm. A bicinchoninic acid assay
and ζ-potential measurements were used to investigate the
adsorption of lysozyme, albumin, or fibrinogen. Each of the
coreâshell particles adsorbed significantly less protein than the
noncoated core (polystyrene) particles. Differences were
observed as both the amount of difunctional, cross-linking
monomer and the amount of shell monomer in the feed were changed. The coreâshell particles were shown to be resistant to
protein adsorption, and the degree to which the three proteins adsorbed was dependent on the formulation of the shell.EPSRC and MR
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Highly-branched poly(N-isopropyl acrylamide) functionalised with pendant Nile red and chain end vancomycin for the detection of Gram-positive bacteria
YesThis study shows how highly branched poly(N-isopropyl acrylamide) (HB-PNIPAM) with a chain pendant solvatochromic dye (Nile red) could provide a fluorescence signal, as end groups bind to bacteria and chain segments become desolvated, indicating the presence of bacteria. Vancomycin was attached to chain ends of HB-PNIPAM or as pendant groups on linear polymers each containing Nile red. Location of the dye was varied between placement in the core of the branched polymer coil or the outer domains. Both calorimetric and fluorescence data showed that branched polymers responded to binding of both the peptide target (D-Ala-D-Aa) and bacteria in a different manner than analogous linear polymers; binding and response was more extensive in the branched variant. The fluorescence data showed that only segments located in the outer domains of branched polymers responded to binding of Gram-positive bacteria with little response when linear analogous polymer or branched polymer with the dye in the inner core was exposed to Staphylococcus aureus.Innovate UK/Smith and Nephew Ltd. (UK) (TSB 103988) and by MRC (MR/N501888/2)
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