376 research outputs found

    RAPE SEED OIL TETRAHYDROFURFURYLESTERS

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    The transesterification of vegetable oil using various kinds of alcohols is a simple and efficient renewable fuel synthesis technique. Products obtained by modifying natural triglycerides in transesterification reaction substitute fossil fuels and mineral oils. Currently the most significant is the biodiesel, a mixture of fatty acid methyl esters, which is obtained in a reaction with methanol, which in turn is obtained from fossil raw materials. In biodiesel production it would be more appropriate to use alcohols which can be obtained from renewable local raw materials. Ethanol rouses interest as a possible reagent, however, its production locally is based on the use of grain and therefore competes with food production so it would implicitly cause increase in food prices. Another raw material option is alcohols that can be obtained from furfurole. Furfurole is obtained in dehydration process from pentose sugars which can be extracted from crop straw, husk and other residues of agricultural production. From furfurole the tetrahydrofurfuryl alcohol (THFA), a raw material for biodiesel, can be produced. By transesterifying rapeseed oil with THFA it would be possible to obtain completely renewable biodiesel with properties very close to diesel [2-4]. With the purpose of developing the synthesis of such fuel, in this work a three-stage synthesis of rapeseed oil tetrahydrofurfurylesters (ROTHFE) in sulphuric acid presence has been performed, achieving product with purity over 98%. The most important qualitative factors of ROTHFE have been determined - cold filter plugging point, cetane number, water content, Iodine value, phosphorus content, density, viscosity and oxidative stability

    ERPs reveal the temporal dynamics of auditory word recognition in specific language impairment.

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    We used event-related potentials (ERPs) to compare auditory word recognition in children with specific language impairment (SLI group; N=14) to a group of typically developing children (TD group; N=14). Subjects were presented with pictures of items and heard auditory words that either matched or mismatched the pictures. Mismatches overlapped expected words in word-onset (cohort mismatches; see: DOLL, hear: dog), rhyme (CONE -bone), or were unrelated (SHELL -mug). In match trials, the SLI group showed a different pattern of N100 responses to auditory stimuli compared to the TD group, indicative of early auditory processing differences in SLI. However, the phonological mapping negativity (PMN) response to mismatching items was comparable across groups, suggesting that just like TD children, children with SLI are capable of establishing phonological expectations and detecting violations of these expectations in an online fashion. Perhaps most importantly, we observed a lack of attenuation of the N400 for rhyming words in the SLI group, which suggests that either these children were not as sensitive to rhyme similarity as their typically developing peers, or did not suppress lexical alternatives to the same extent. These findings help shed light on the underlying deficits responsible for SLI

    Clinical characteristics of persistent frequent attenders in primary care: case–control study

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    Background. Most frequent attendance in primary care is temporary, but persistent frequent attendance is expensive and may be suitable for psychological intervention. To plan appropriate intervention and service delivery, there is a need for research involving standardized psychiatric interviews with assessment of physical health and health status. Objective. To compare the mental and physical health characteristics and health status of persistent frequent attenders (FAs) in primary care, currently and over the preceding 2 years, with normal attenders (NAs) matched by age, gender and general practice. Methods. Case–control study of 71 FAs (30 or more GP or practice nurse consultations in 2 years) and 71 NAs, drawn from five primary care practices, employing standardized psychiatric interview, quality of life, health anxiety and primary care electronic record review over the preceding 2 years. Results. Compared to NAs, FAs were more likely to report a lower quality of life (P < 0.001), be unmarried (P = 0.03) and have no educational qualifications (P = 0.009) but did not differ in employment status. FAs experienced greater health anxiety (P < 0.001), morbid obesity (P = 0.02), pain (P < 0.001) and long-term pathological and ill-defined physical conditions (P < 0.001). FAs had more depression including dysthymia, anxiety and somatoform disorders (all P < 0.001). Conclusions. Persistent frequent attendance in primary care was associated with poor quality of life and high clinical complexity characterized by diverse and often persistent physical and mental multimorbidity. A brokerage model with GPs working in close liaison with skilled psychological therapists is required to manage such persistent complexity

    Protocol investigating the clinical outcomes and cost-effectiveness of cognitive–behavioural therapy delivered remotely for unscheduled care users with health anxiety: randomised controlled trial

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    Background Health anxiety and medically unexplained symptoms cost the National Health Service (NHS) an estimated £3 billion per year in unnecessary costs with little evidence of patient benefit. Effective treatment is rarely taken up due to issues such as stigma or previous negative experiences with mental health services. An approach to overcome this might be to offer remotely delivered psychological therapy, which can be just as effective as face-to-face therapy and may be more accessible and suitable. Aims To investigate the clinical outcomes and cost-effectiveness of remotely delivered cognitive–behavioural therapy (CBT) to people with high health anxiety repeatedly accessing unscheduled care (trial registration: NCT02298036). Method A multicentre randomised controlled trial (RCT) will be undertaken in primary and secondary care providers of unscheduled care across the East Midlands. One hundred and forty-four eligible participants will be equally randomised to receive either remote CBT (6–12 sessions) or treatment as usual (TAU). Two doctoral research studies will investigate the barriers and facilitators to delivering the intervention and the factors contributing to the optimisation of therapeutic outcome. Results This trial will be the first to test the clinical outcomes and costeffectiveness of remotely delivered CBT for the treatment of high health anxiety. Conclusions The findings will enable an understanding as to how this intervention might fit into a wider care pathway to enhance patient experience of care

    Fluorescent carbon dioxide indicators

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    Over the last decade, fluorescence has become the dominant tool in biotechnology and medical imaging. These exciting advances have been underpinned by the advances in time-resolved techniques and instrumentation, probe design, chemical / biochemical sensing, coupled with our furthered knowledge in biology. Complementary volumes 9 and 10, Advanced Concepts of Fluorescence Sensing: Small Molecule Sensing and Advanced Concepts of Fluorescence Sensing: Macromolecular Sensing, aim to summarize the current state of the art in fluorescent sensing. For this reason, Drs. Geddes and Lakowicz have invited chapters, encompassing a broad range of fluorescence sensing techniques. Some chapters deal with small molecule sensors, such as for anions, cations, and CO2, while others summarize recent advances in protein-based and macromolecular sensors. The Editors have, however, not included DNA or RNA based sensing in this volume, as this were reviewed in Volume 7 and is to be the subject of a more detailed volume in the near future

    Assessment of the potential in vivo ecotoxicity of Double-Walled Carbon Nanotubes (DWNTs) in water, using the amphibian Ambystoma mexicanum

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    Because of their specific properties (mechanical, electrical, etc), carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to their massive production and number of potential applications, the impact of CNTs on the environment must be taken into consideration. The present investigation evaluates the ecotoxic potential of CNTs in the amphibian larvae (Ambystoma mexicanum). Acute toxicity and genotoxicity were analysed after 12 days of exposure in laboratory conditions. The genotoxic effects were analysed by scoring the micronucleated erythrocytes in the circulating blood of the larvae according to the French standard micronucleus assay. The results obtained in the present study demonstrated that CNTs are neither acutely toxic nor genotoxic to larvae whatever the CNTs concentration in the water, although black masses of CNTs were observed inside the gut. In the increasing economical context of CNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations

    Multiwavelength Observations of Supersonic Plasma Blob Triggered by Reconnection Generated Velocity Pulse in AR10808

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    Using multi-wavelength observations of Solar and Heliospheric Observatory (SoHO)/Michelson Doppler Imager (MDI), Transition Region and Coronal Explorer (TRACE) 171 \AA, and Hα\alpha from Culgoora Solar Observatory at Narrabri, Australia, we present a unique observational signature of a propagating supersonic plasma blob before an M6.2 class solar flare in AR10808 on 9th September 2005. The blob was observed between 05:27 UT to 05:32 UT with almost a constant shape for the first 2-3 minutes, and thereafter it quickly vanished in the corona. The observed lower bound speed of the blob is estimated as \sim215 km s1^{-1} in its dynamical phase. The evidence of the blob with almost similar shape and velocity concurrent in Hα\alpha and TRACE 171 \AA\ supports its formation by multi-temperature plasma. The energy release by a recurrent 3-D reconnection process via the separator dome below the magnetic null point, between the emerging flux and pre-existing field lines in the lower solar atmosphere, is found to be the driver of a radial velocity pulse outwards that accelerates this plasma blob in the solar atmosphere. In support of identification of the possible driver of the observed eruption, we solve the two-dimensional ideal magnetohydrodynamic equations numerically to simulate the observed supersonic plasma blob. The numerical modelling closely match the observed velocity, evolution of multi-temperature plasma, and quick vanishing of the blob found in the observations. Under typical coronal conditions, such blobs may also carry an energy flux of 7.0×106\times10^{6} ergs cm2^{-2} s1^{-1} to re-balance the coronal losses above active regions.Comment: Solar Physics; 22 Pages; 8 Figure

    Geometric frustration in small colloidal clusters

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    We study the structure of clusters in a model colloidal system with competing interactions using Brownian dynamics simulations. A short-ranged attraction drives clustering, while a weak, long-ranged repulsion is used to model electrostatic charging in experimental systems. The former is treated with a short-ranged Morse attractive interaction, the latter with a repulsive Yukawa interaction. We consider the yield of clusters of specific structure as a function of the strength of the interactions, for clusters with m=3,4,5,6,7,10 and 13 colloids. At sufficient strengths of the attractive interaction (around 10 kT), the average bond lifetime approaches the simulation timescale and the system becomes nonergodic. For small clusters m<=5 where geometric frustration is not relevant, despite nonergodicity, for sufficient strengths of the attractive interaction the yield of clusters which maximise the number of bonds approaches 100%. However for m=7m=7 and higher, in the nonergodic regime we find a lower yield of these structures where we argue geometric frustration plays a significant role. m=6m=6 is a special case, where two structures, of octahedral and C2v symmetry compete, with the latter being favoured by entropic contributions in the ergodic regime and by kinetic trapping in the nonergodic regime. We believe that our results should be valid as far as the one-component description of the interaction potential is valid. A system with competing electrostatic repulsions and van der Waals attractions may be such an example. However, in some cases, the one-component description of the interaction potential may not be appropriate.Comment: 21 pages, accepted for publication by J. Phys. Condens. Matte

    Oscillations and waves in solar spicules

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    Since their discovery, spicules have attracted increased attention as energy/mass bridges between the dense and dynamic photosphere and the tenuous hot solar corona. Mechanical energy of photospheric random and coherent motions can be guided by magnetic field lines, spanning from the interior to the upper parts of the solar atmosphere, in the form of waves and oscillations. Since spicules are one of the most pronounced features of the chromosphere, the energy transport they participate in can be traced by the observations of their oscillatory motions. Oscillations in spicules have been observed for a long time. However the recent high-resolutions and high-cadence space and ground based facilities with superb spatial, temporal and spectral capacities brought new aspects in the research of spicule dynamics. Here we review the progress made in imaging and spectroscopic observations of waves and oscillations in spicules. The observations are accompanied by a discussion on theoretical modelling and interpretations of these oscillations. Finally, we embark on the recent developments made on the presence and role of Alfven and kink waves in spicules. We also address the extensive debate made on the Alfven versus kink waves in the context of the explanation of the observed transverse oscillations of spicule axes
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