140 research outputs found
Effect of Rotation Speed of a Rotary Wheel on Ventilation Supply Rates of Wind Tower System
This study explores the integration of a rotary thermal wheel into a wind tower system, specifically the effect of the rotation speed on the ventilation rate and heat recovery. Wind towers are capable of supplying recommended levels of supply air under a range of external conditions, integrating a rotary thermal wheel will cause a reduction in the air supply rates due to the blockage created by the wheel. Using Computational Fluid Dynamics (CFD) analysis, the air supply rate and heat transfer of the rotary thermal wheel have been calculated for a range of rotation speeds between 0rpm – 500rpm. The recommended air supply rate of 8l/s/p is attained up to a rotation speed of 50rpm; beyond this rotation speed the air supply rate is too low. The maximum temperature recovered across the rotary thermal wheel is measured as 1.77°C at a rotation speed of 20rpm. Using the two results gained from the analysis, an optimum operating range of the rotary thermal wheel can be determined between 5rpm and 20rpm. The technology presented here is subject to an international patent application (PCT/GB2014/052513)
CFD and Wind Tunnel Study of the Performance of a Multi-Directional Wind Tower with Heat Transfer Devices
The aim of this work was to investigate the performance of a multi-directional wind tower integrated with heat transfer devices (HTD) using Computational Fluid Dynamics (CFD) and wind tunnel analysis. An experimental scale model was created using 3D printing. The scale model was tested in a closed-loop wind tunnel to validate the CFD data. Numerical results of the supply airflow were compared with experimental data. Good agreement was observed between both methods of analysis. Smoke visualisation test was conducted to analyse the air flow pattern in the test room attached underneath it. Results have indicated that the achieved indoor air speed was reduced by up to 17% following the integration of the cylindrical HTD. The effect of varying the number of HTD on the system's thermal performance were investigated. The work highlighted the potential of integrating HTD into wind towers in reducing the air temperature. The technology presented here is subject to a UK patent application (PCT/GB2014/052263)
A framework for producing gbXML building geometry from Point Clouds for accurate and efficient Building Energy Modelling
The industrial sector accounts for 17% of end-use energy in the United Kingdom, and 54% globally. Therefore, there is substantial scope to accurately simulate and efficiently assess potential energy retrofit options for industrial buildings to lower end use energy. Due to potentially years of facility renovation and expansion Building Energy Modelling, also called Building Energy Simulation, applied to industrial buildings poses a complex challenge; but it is an important opportunity for reducing global energy demand especially considering the increase of readily available computational power compared with a few years ago. Large and complex industrial buildings make modelling existing geometry for Building Energy Modelling difficult and time consuming which impacts analysis workflow and assessment options available within reasonable budgets. This research presents a potential framework for quickly capturing and processing as-built geometry of a factory, or other large scale buildings, to be utilised in Building Energy Modelling by storing the geometry in a green building eXtensible Mark-up Language (gbXML) format, which is compatible with most commercially available Building Energy Modelling tools. Laser scans were captured from the interior of an industrial facility to produce a Point Cloud. The existing capabilities of a Point Cloud processing software and previous research were assessed to identify the potential development opportunities to automate the conversion of Point Clouds to building geometry for Building Energy Modelling applications. This led to the novel identification of a framework for storing the building geometry in the gbXML format and plans for verification of a future Point Cloud processing solution. This resulted in a sample Point Cloud, of a portion of a building, being converted into a gbXML model that met the validation requirements of the gbXML definition schema. In conclusion, an opportunity exists for increasing the speed of 3D geometry creation of existing industrial buildings for application in BEM and subsequent thermal simulation
Geometry Extraction for High Resolution Building Energy Modelling Applications from Point Cloud Data: A Case Study of a Factory Facility
The industrial sector accounts for 17% of end-use energy in the UK, and 54% globally. Therefore, there is substantial scope for simulating and assessing potential energy retrofit options for industrial buildings. Building Energy Modelling (BEM) applied to industrial buildings p oses a complex but important opportunity for reducing global energy demand, due to years of renovation and expansion. Large and complex industrial buildings make modelling existing geometry for BEM difficult and time consuming. This paper presents a potential solution for quickly capturing and processing as-built geometry of a factory to be utilized in BEM. Laser scans were captured from the interior of an industrial facility to produce a Point Cloud. The existing capabilities of a Point Cloud processing software were assessed to identify the potential development opportunities to automate the conversion of Point Clouds to building geometry for BEM applications. In conclusion, scope exists for increasing the speed of 3D geometry creation of an existing industrial building for application in BEM and subsequent thermal simulation
Numerical and experimental analysis of a natural ventilation windcatcher with passive heat recovery for mild-cold climates
In this work, a novel design incorporating a passive heat recovery device into a windcatcher was proposed and investigated using numerical and experimental analysis. The proposed system incorporates a rotary thermal heat recovery in the windcatcher channel. Computational Fluid Dynamics (CFD) was used to investigate the effect of the heat recovery device on the performance of the windcatcher, highlighting the capabilities of the system to deliver the required fresh air rates. The windcatcher model was incorporated to a 5m x 5m x 3m test room model representing a small classroom. The study employed the CFD code Fluent18 with the k-epsilon model to conduct the simulations. The numerical model provided detailed analysis of the airflow and temperature distribution inside the test room. A 1:10 scale prototype of the system was created and tested experimentally in a closed-loop subsonic wind tunnel to validate the CFD investigations. Despite the blockage of the rotary t heat recovery wheel, ventilation rates were able to provide adequate ventilation. In addition to sufficient ventilation, the heat in the exhaust airstreams was captured and transferred to the incoming airstream, raising the temperature between 1-4K depending on the indoor/outdoor conditions, this passive recovery has the potential to reduce demand on space heating systems. According to WBCSD, a recovery of 3 K from the exhaust stream to the inlet stream could generate energy savings up to 20% in heating costs. This shows that the concept has significant potential to be developed further, whereby the heat transfer properties of the system can be investigated and tested on a larger scale
Pre-injury Comorbidities Are Associated With Functional Impairment and Post-concussive Symptoms at 3-and 6-Months After Mild Traumatic Brain Injury: A TRACK-TBI Study
Introduction: Over 70% of traumatic brain injuries (TBI) are classified as mild (mTBI),
which present heterogeneously. Associations between pre-injury comorbidities and
outcomes are not well-understood, and understanding their status as risk factors may
improve mTBI management and prognostication.
Methods: mTBI subjects (GCS 13–15) from TRACK-TBI Pilot completing 3- and
6-month functional [Glasgow Outcome Scale-Extended (GOSE)] and post-concussive
outcomes [Acute Concussion Evaluation (ACE) physical/cognitive/sleep/emotional
subdomains] were extracted. Pre-injury comorbidities >10% incidence were included
in regressions for functional disability (GOSE ≤ 6) and post-concussive symptoms by
subdomain. Odds ratios (OR) and mean differences (B) were reported. Significance was
assessed at p < 0.0083 (Bonferroni correction).
Results: In 260 subjects sustaining blunt mTBI, mean age was 44.0-years and 70.4%
were male. Baseline comorbidities >10% incidence included psychiatric-30.0%, cardiac
(hypertension)-23.8%, cardiac (structural/valvular/ischemic)-20.4%, gastrointestinal15.8%, pulmonary-15.0%, and headache/migraine-11.5%. At 3- and 6-months
separately, 30.8% had GOSE ≤ 6. At 3-months, psychiatric (GOSE ≤ 6: OR = 2.75,
95% CI [1.44–5.27]; ACE-physical: B = 1.06 [0.38–1.73]; ACE-cognitive: B = 0.72
[0.26–1.17]; ACE-sleep: B = 0.46 [0.17–0.75]; ACE-emotional: B = 0.64 [0.25–1.03]), headache/migraine (GOSE ≤ 6: OR = 4.10 [1.67–10.07]; ACE-sleep: B = 0.57
[0.15–1.00]; ACE-emotional: B = 0.92 [0.35–1.49]), and gastrointestinal history
(ACE-physical: B = 1.25 [0.41–2.10]) were multivariable predictors of worse outcomes.
At 6-months, psychiatric (GOSE ≤ 6: OR = 2.57 [1.38–4.77]; ACE-physical: B = 1.38
[0.68–2.09]; ACE-cognitive: B = 0.74 [0.28–1.20]; ACE-sleep: B = 0.51 [0.20–0.83];
ACE-emotional: B = 0.93 [0.53–1.33]), and headache/migraine history (ACE-physical:
B = 1.81 [0.79–2.84]) predicted worse outcomes.
Conclusions: Pre-injury psychiat
Psychology and aggression
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68264/2/10.1177_002200275900300301.pd
Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector
A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance
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