3,773 research outputs found

    Three-Dimensional High-Resolution Urban Thermal & Mechanical Large Eddy Simulation Interactive Physics Between Buildings, Land Cover And Trees

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    This paper describes the development of a 3D model of the non-domestic building stock of England and Wales. The model’s purpose is to assess energy use in the stock, and study conservation options. Previous stock models have used data on floor area by activities, and have not represented building geometry. The present model by contrast combines digital maps and property taxation data to build a 3D representation in which separate premises are located within buildings, with floor areas on each level. Sub-activities per floor are also represented in 2D. A case study of the London Borough of Camden is presented

    Examining The Physical Demands of Elite Rugby League Match-Play

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    The work undertaken from the studies in this thesis provides novel information in relation to the physical match demands of the European Super League (ESL) competition, focusing on a newly promoted ESL franchise. Specifically, this is the first work to examine the physical demands of competition for an entire squad of players across an entire competitive season in the ESL, the first to examine the physical demands of match-play over multiple longitudinal seasons, and the first to examine the effects of different between match recovery periods on the running demands for a large sample of ESL teams. Methodological work in this thesis has also highlighted the importance of quantifying and interpreting errors associated with GPS devices to quantify player movements and collisions. Chapter 4 examined the physical match demands for the newly promoted team over the entirety of a competitive season. Significant positional differences were evident, with Outside Backs (OB, 421 ± 89 m) and Pivots (PIV, 306 ± 108 m) performing more sprinting than Middle Unit Forwards (MUF, 185 ± 58 m) and Wide Running Forwards (296 ± 82 m). Conversely, MUF (35 ± 6) and WRF (36 ± 5) performed more collisions than PIV (23 ± 3) and OB (20 ± 3). Practitioners need to be aware of these differences when designing training and conditioning programmes for players. The high speed running (HSR) and number of collisions were greater for the newly promoted team than previously reported for higher ranked ESL teams, but are still lower than those experienced in the southern hemisphere National Rugby League (NRL). Chapter 5 examined the level of agreement between two different models of GPS device in measuring the total distance, and distance covered at high speed (> 5.0 m.s-1) in order that these could be examined in following chapters where two different models of device were used. The two devices showed acceptable levels of agreement in relation to specific analytical goals using positional data from Chapter 4 (total distance CV 0.8%, HSR CV 2.2%) and in relation to the differences between games won and lost at the elite level (mean bias [95% LoA] -0.29 m.min-1 [-1.6 m to 1.01 m.min-1] for total distance per minute, and 0.01 m.min-1 [-0.27 to 0.29 m.min-1] for HSR distance per minute)concluding the two devices could be used interchangeably to measure these parameters. Chapter 6 examined the physical demands of match-play for the newly promoted franchise over a three season period (2012-2014). There was an increase in the physical demands of competition in terms of the total distance coverer per minute (87.0 ± 2.4 m.min-1 – 96.6 ± 2.4 m.min-1), HSR distance covered per minute (6.3 ± 1.3 m.min-1 – 8.1 ± 0.5 m.min-1), and number of collisions per minute (0.43 ± 0.05 no.min-1 – 0.53 ± 0.04 m.min-1). These findings highlight that newly promoted teams need time to develop and adapt to the increasing demands of competition, which is a pertinent issue given the re-introduction of promotion and relegation from 2015. With the current structure, newly promoted teams will not have the chance to plan and develop over the long term, which could leads to teams spending over their means to attract the players required to keep them in the competition rather than focussing on long term player development. Chapter 7 examined the effectiveness of a wearable GPS device to automatically detect collision events during elite Rugby League match-play. The overall error of the device (19%) was associated with not correctly identifying a collision has occurred. Ball carries (97%) were more accurately detected than when compared to tackles (73%). First man tackles (83%) were more accurately detected than second man tackles (72%), and third man tackles (51%). This data suggests the microsensor device has the ability to automatically detect the majority of collision events in Rugby League match-play. However given the collision detection algorithm was originally developed for use in Rugby Union; this may need refinement for use in Rugby League, especially for detecting tackle events. Chapter 8 examined the effect of different between match recovery cycles (short, medium, and long) on the movement demands in subsequent matches on a larger sample of six elite ESL teams. Matches after a short turnaround were associated with greater HSR distance covered per minute of play (13.2 ± 6.9 m.min-1) than when compared to medium (11.6 ± 5.8 m.min-1) and long turnarounds (10.6 ± 5.6 m.min-1). Matches with long turnarounds were associated with increased low speed distance (< 3.8 m.s-1) covered per minute of play (84.8 ± 18.2 m.min-1) than both medium (79.3 ± 19.6 m.min-1) and short turnarounds (80.3 ± 17.7 m.min-1). The total distance covered per minute was only greater on a long turnaround (96.1 ± 16.9 m.min-1) when compared to a medium turnaround(72.9 ± 21.8 m.min-1). These data demonstrate that running performance is affected by the length of the between match recovery cycle, and coaches and conditioning staff working within the ESL should be mindful of these demands when developing recovery and training strategies for their players

    Kinetically controlled fabrication of gold nanorods and investigation of their thermal stability via in-situ TEM heating

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    Size controlled CTAB-capped AuNRs with various aspect ratios (ARs) ranging from 1.63±0.13 to 4.12±0.25 were synthesized following a modified seed-mediated method. Their thermal stability was examined by in-situ TEM heating. The results revealed a structural change from rods to spheres with increasing temperature. At lower temperatures 600ºC, particles became increasingly spherical. This behaviour occurred at temperatures lower than the melting point of bulk gold supporting a surface diffusion mechanism with material diffusing from the tips and redepositing at the middle of the rods. The rate of change in AR appeared to increase for thinner AuNRs

    Reversible metallisation of soft UV patterned substrates

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    Soft UV (365 nm) patterning of ortho-nitrobenzyl functionalized thiol-on-gold self-assembled monolayers (SAMs) using acid catalysis, produces surfaces which can be used for the selective electro-deposition of copper. Exploiting the difference in the reduction peak potential between the photolysed and the masked regions of the SAM allows copper to be deposited selectively on those areas that have been exposed to the light. The copper can be removed by raising the electrode potential. The process is fully reversible so that depositing a pattern of copper, and removing it again is something that can be repeated many times. The copper deposited on the photolysed regions, like copper deposited on bare gold, forms a film of copper oxide, and so it is presumably formed on top of the SAM. Preliminary results for two-photon photocleavage show that it is also possible to implement patterning with sub-wavelength features

    ent-Clerodane Diterpenes from the Bark of Croton oligandrus Pierre ex. Hutch. and Assessment of their Cytotoxicity Against Human Cancer Cell Lines

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    New clerodane diterpenes, 12-epi-megalocarpodolide D (2) and an epimeric mixture of crotonolins A (3) and B (4), were isolated from the bark of Croton oligandrus following a bioassay-guided isolation protocol. Known compounds, megalocarpodolide D (1), 12-epi-crotocorylifuran (5), cluytyl-ferulate (6), hexacosanoyl- ferulate (7), vanillin (8), acetyl-aleuritolic acid (9) and lupeol (10), were also isolated. The structures of the isolated compounds (1-10) were elucidated by spectroscopic means. The cytotoxicity of compounds 1-10 was assessed against A549, MCF7, PC3 and PNT2 cell lines using the MTT assay. Compounds 1 and 2 showed moderate level of activity against both A549 and MCF7 cells with 1 being the most active with IC50 values of 63.8±13.8 and 136.2±22.7 µM against A549 and MCF7 cells, respectively. The epimeric mixture of 3 and 4 was moderately active against A549 and PC3 cells (IC50 = 128.6±31.0 and 111.2±2.9 µM, respectively)

    On-chip production of nanometer sized 'Ultra fine' bubble populations

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    Microbubble (MB) contrast agents have been used for many years as image enhancers for medical Ultrasound (US). Ultra-Fine bubble (UFB) populations of bubbles <1 µm in diameter are a relatively new technology that has found use as highly effective ‘eco’ cleaning agents. High-resolution US imaging is another potentially exciting area for UFB. This paper reports the on-chip production of UFB populations with a diameter of ~ 500 – 700 nm at a concentration of 10¹⁰ bub / mL. These UFB showed US scattering at higher frequency fields and enhanced contrast when imaging in in vivo mouse models

    Optimization of Brownian ratchets for the manipulation of charged components within supported lipid bilayers

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    In probability theory, there is a counter-intuitive result that it is possible to construct a winning strategy from two individually losing (or at most breaking-even) "games" by alternating between them. The work presented here demonstrates the application of this principle to supported lipid bilayers (SLBs) in order to create directed motion of charged lipid components in the membrane, which was achieved through the use of "Brownian ratchets" in patterned SLBs. Both a finite element analysis model and an experimental setup have been used to investigate the role of key parameters for the operation of these ratchets: (1) the asymmetry of the ratchet teeth and (2) the relation of the ratchet height to the period of the applied electric field. Importantly, we find that the efficiency of the ratchet for a given charged species is dependent on the diffusion coefficient. This opens the possibility for separation of membrane species according to their size or viscous drag coefficient within the membrane

    A comparison between direct and pan-derived measurements of the isotopic composition of atmospheric waters

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    The stable isotopes of water can be used to examine and quantify the contribution to atmospheric moisture from evaporation, transpiration and surface-waters. However, obtaining extensive and ongoing time series data of the isotopic composition of atmospheric moisture has been difficult. Presented here is an alternate method using an isotope mass balance approach to estimate the isotopic composition of atmospheric moisture using water samples collected from class A evaporation pans. While this evaporation pan method does not provide the high-resolution time series data that can be obtained from an isotope analyser taking in-situ measurements of atmospheric moisture, the method is relatively simple and inexpensive to set-up and maintain. In this preliminary investigation, a comparison between the isotopic composition of atmospheric moisture estimated from the evaporation pan method and in-situ measurements of the isotopic composition of water vapour using a Fourier Transform Infrared (FTIR) spectrometer deployed at the Lucas Heights weather station in New South Wales is undertaken. Through comparison of the two series of hydrogen isotope data, an assessment of the evaporation pan method can be made. Although there was some agreement between the isotopic composition of vapour measured by the FTIR spectrometer and the estimation for the atmospheric moisture (R2 = 0.49), the comparison is sensitive to climatic parameters that vary significantly within a 24-hour period such as the relative humidity of air and the air and pan temperatures. Inverting the model to use the FTIR spectrometer measurements at an hourly resolution improved the performance of the model (R2 =0.57). However, this also revealed that the model produced more depleted values of the evaporation pan water isotopes than those observed. In contrast, there was a variable relationship between the modelled and observed isotope values of atmospheric moisture. These conflicting results will need to be resolved before the evaporation pan method is broadly applied in isotope hydrology. © 2011 The Modelling and Simulation Society of Australia and New Zealand Inc
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