57 research outputs found

    Development of Cosmic Ray Simulation Program -- Earth Cosmic Ray Shower (ECRS)

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    ECRS is a program for the detailed simulation of extensive air shower initiated by high energy cosmic ray particles. In this dissertation work, a Geant4 based ECRS simulation was designed and developed to study secondary cosmic ray particle showers in the full range of Earth\u27s atmosphere. A proper atmospheric air density and geomagnetic field are implemented in order to correctly simulate the charged particles interactions in the Earth\u27s atmosphere. The initial simulation was done for the Atlanta (33.460 N , 84.250 W) region. Four different types of primary proton energies (109, 1010, 1011 and 1012 eV) were considered to determine the secondary particle distribution at the Earth\u27s surface. The geomagnetic field and atmospheric air density have considerable effects on the muon particle distribution at the Earth\u27s surface. The muon charge ratio at the Earth\u27s surface was studied with ECRS simulation for two different geomagnetic locations: Atlanta, Georgia, USA and Lynn Lake, Manitoba, Canada. The simulation results are shown in excellent agreement with the data from NMSU-WIZARD/CAPRICE and BESS experiments at Lynn Lake. At low momentum, ground level muon charge ratios show latitude dependent geomagnetic effects for both Atlanta and Lynn Lake from the simulation. The simulated charge ratio is 1.20 ± 0.05 (without geomagnetic field), 1.12 ± 0.05 (with geomagnetic field) for Atlanta and 1.22 ± 0.04 (with geomagnetic field) for Lynn Lake. These types of studies are very important for analyzing secondary cosmic ray muon flux distribution at the Earth\u27s surface and can be used to study the atmospheric neutrino oscillations

    Prehabilitation in elective patients undergoing cardiac surgery: a randomised control trial (THE PrEPS TRIAL) – a study protocol

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    Introduction: Prehabilitation prior to surgery has been shown to reduce postoperative complications, reduce length of hospital stay and improve quality of life after cancer and limb reconstruction surgery. However, there are minimal data on the impact of prehabilitation in patients undergoing cardiac surgery, despite the fact these patients are generally older and have more comorbidities and frailty. This trial will assess the feasibility and impact of a prehabilitation intervention consisting of exercise and inspiratory muscle training on preoperative functional exercise capacity in adult patients awaiting elective cardiac surgery, and determine any impact on clinical outcomes after surgery. Methods and analysis: PrEPS is a randomised controlled single-centre trial recruiting 180 participants undergoing elective cardiac surgery. Participants will be randomised in a 1:1 ratio to standard presurgical care or standard care plus a prehabilitation intervention. The primary outcome will be change in functional exercise capacity measured as change in the 6 min walk test distance from baseline. Secondary outcomes will evaluate the impact of prehabilitation on preoperative and postoperative outcomes including; respiratory function, health-related quality of life, anxiety and depression, frailty, and postoperative complications and resource use. This trial will evaluate if a prehabilitation intervention can improve preoperative physical function, inspiratory muscle function, frailty and quality of life prior to surgery in elective patients awaiting cardiac surgery, and impact postoperative outcomes. Ethics and dissemination: A favourable opinion was given by the Sheffield Research Ethics Committee in 2019. Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer-reviewed publication

    High-affinity RNA binding by a hyperthermophilic single-stranded DNA-binding protein

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    Single-stranded DNA-binding proteins (SSBs), including replication protein A (RPA) in eukaryotes, play a central role in DNA replication, recombination, and repair. SSBs utilise an oligonucleotide/oligosaccharide-binding (OB) fold domain to bind DNA, and typically oligomerise in solution to bring multiple OB fold domains together in the functional SSB. SSBs from hyperthermophilic crenarchaea, such as Sulfolobus solfataricus, have an unusual structure with a single OB fold coupled to a flexible C-terminal tail. The OB fold resembles those in RPA, whilst the tail is reminiscent of bacterial SSBs and mediates interaction with other proteins. One paradigm in the field is that SSBs bind specifically to ssDNA and much less strongly to RNA, ensuring that their functions are restricted to DNA metabolism. Here, we use a combination of biochemical and biophysical approaches to demonstrate that the binding properties of S. solfataricus SSB are essentially identical for ssDNA and ssRNA. These features may represent an adaptation to a hyperthermophilic lifestyle, where DNA and RNA damage is a more frequent event.Publisher PDFPeer reviewe

    A review on boiling heat transfer enhancement with nanofluids

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    There has been increasing interest of late in nanofluid boiling and its use in heat transfer enhancement. This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid. The available data in the literature is reviewed in terms of enhancements, and degradations in the nucleate boiling heat transfer and critical heat flux. Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling. Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement

    Supervised methods of image segmentation accuracy assessment in land cover mapping

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    Land cover mapping via image classification is sometimes realized through object-based image analysis. Objects are typically constructed by partitioning imagery into spatially contiguous groups of pixels through image segmentation and used as the basic spatial unit of analysis. As it is typically desirable to know the accuracy with which the objects have been delimited prior to undertaking the classification, numerous methods have been used for accuracy assessment. This paper reviews the state-of-the-art of image segmentation accuracy assessment in land cover mapping applications. First the literature published in three major remote sensing journals during 2014–2015 is reviewed to provide an overview of the field. This revealed that qualitative assessment based on visual interpretation was a widely-used method, but a range of quantitative approaches is available. In particular, the empirical discrepancy or supervised methods that use reference data for assessment are thoroughly reviewed as they were the most frequently used approach in the literature surveyed. Supervised methods are grouped into two main categories, geometric and non-geometric, and are translated here to a common notation which enables them to be coherently and unambiguously described. Some key considerations on method selection for land cover mapping applications are provided, and some research needs are discussed

    Microscopic characteristics of biodiesel – Graphene oxide nanoparticle blends and their Utilisation in a compression ignition engine

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    Use of nano-additives in biofuels is an important research and development topic for achieving optimum engine performance with reduced emissions. In this study, rice bran oil was converted into biodiesel and graphene oxide (GO) nanoparticles were infused into biodiesel-diesel blends. Two blends containing (i) 5% biodiesel, 95% diesel and 30 ppm GO (B5D95GO30) and (ii) 15% biodiesel, 85% diesel and 30 ppm GO (B15D85GO30) were prepared. The fuel properties like heating value, kinematic viscosity, cetane number, etc. of the nanoadditives–biodiesel-diesel blends (NBDB) were measured. Effects of injection timing (IT) on the performance, combustion and emission characteristics were studied. It was observed that both B15D85GO30 and B5D95GO30 blends at IT23° gave up to 13.5% reduction in specific fuel consumption. Compared to diesel, the brake thermal efficiency was increased by 7.62% for B15D85GO30 at IT23° and IT25°. An increase in IT from 23° to 25° deteriorated the indicated thermal efficiency by 6.68% for B15D85GO30. At maximum load condition, the peak heat release rates of NBDB were found to be lower than the pure diesel at both IT. The CO, CO2 & NOx emissions were reduced by 2–8%. The study concluded that B15D85GO30 at IT23° gave optimum results in terms of performance, combustion and emission characteristics

    Analysis of sensory information for efficient operation of energy management systems in commercial hotels

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    Due to fluctuating energy prices and ever-increasing uncertainties in supply, the industrial and commercial sectors are poised to speed up introduction of energy saving mechanisms. Having badly hit by re-cent economic recession, the hotel industry has ever more reasons to save energy. A typical star-class hotel was chosen to conduct the energy usage optimization study presented in this paper. The hotel’s energy con-sumption pattern data was collected and analysed. Based on sensor information and manage information sys-tem data, cooling load requirement is correlated with the number of occupied rooms. It is shown that substan-tial savings can be achieved by introduction of wing operation to the hotel room allocation system. Moreover, the findings from the present study can be incorporated into a building management system (BMS) when it comes to automating the wing operations
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