bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-Grade Heat Utilization Through Ultrasound-Enhanced Desorption of Activated Alumina/Water for Thermal Energy Storage
Authors: Daghooghi Mobarakeh Hooman , Bandara Keshawa , Wang Liping , Wang Robert , Phelan Patrick E. , Miner Mark 
Published: October 2020

Abstract
Sorption thermal energy storage (TES) seems to be an auspicious solution to overcome the issues of intermittent energy sources and utilization of low-grade heat. Ultrasound-assisted adsorption/desorption of water vapor on activated alumina is proposed as a means of low-grade heat utilization through TES. The effects of ultrasonic power on the storing stage (desorption of water vapor) were analyzed to optimize the desorption and overall efficiencies. To determine and justify the effectiveness of incorporating ultrasound from an energy-savings point of view, an approach of constant total (heat plus ultrasound) input power of 25 W was adopted. To measure the extent of the effectiveness of using ultrasound, ultrasonic-power-to-total power ratios of 0.2 and 0.4 were investigated and the results compared with those of no-ultrasound (heat only) at the same total power. The regeneration temperature and desorption rate were measured simultaneously to investigate the effects of ultrasonication on regeneration temperature and utilization of low-grade heat. The experimental results showed that using ultrasound facilitates the regeneration of activated alumina at both power ratios without increasing the total input power. With regard to regeneration temperature, incorporating ultrasound decreases the regeneration temperature hence justifying the utilization of low-grade heat for thermal energy purposes. In terms of overall energy recovery of the adsorption thermal storage process, a new metric is proposed to justify incorporating ultrasound and any other auxiliary energy along with low-grade heat.
Performance Analysis and Optimization of Flue Gas Waste Heat Recovery System of a 600MW Coal-Fired Power Plant
Authors: Chen Xun , Xu Shu , Yang Yi , Wang Li-min , Wang Dun-dun 
Published: October 2020

Abstract
Recovering the waste heat of the flue gas from the boilers of coal-fired units, so that part of the boiler’s flue gas waste heat can be utilized in the turbine regenerative heating system is an important way to increase efficiency and reduce emissions of coal-fired units. In this paper, a 600MW supercritical coal-fired unit is taken as an example, and the conceptual design of a flue gas waste heat cascade utilization system is carried out. Based on the first and second laws of thermodynamics, the thermodynamic perfection of the heat transfer process of the rotary regenerative air preheater, the exergy efficiency of the heat displacement process of the flue gas waste heat cascade utilization system, and the overall performance parameters of the coal-fired unit are calculated and analyzed under different parameters such as the bypass flue ratio and the inlet air temperature of the regenerative air preheater. The energy-saving effect of flue gas waste heat cascade utilization system is restricted by factors such as acid dew point temperature, ammonium bisulfate (ABS) deposition inside the air preheater, etc. Based on the performance analysis of regenerative air preheater and ABS deposition law, considering the structural characteristics and operating parameters of air preheater, this paper gives a criterion number (R-number) of ABS deposition tendency, and analyzes the actual operation performance of flue gas waste heat cascade utilization system considering the restrictions.
Data Analytics Applied to Coal Fired Boilers for Detecting Leaks
Authors: Indrawan Natarianto , Panday Rupendranath , Shadle Lawrence J. , Chitnis Umesh K. 
Published: October 2020

Abstract
Data analytics were used to detect boiler leaks from five different coal-fired boilers including both subcritical and supercritical systems. Discriminant functions were developed that detected leaks up to two weeks prior to forced plant shutdowns for repairs. The leaks were identified to occur at different sections of the boiler for each plant, including waterwalls, economizer and superheater using conventional process measurement data. Leaking conditions were detected with a high degree of confidence (≪ 1% misclassified observations) and were able to distinguish normal operations from those time periods with steam leaks even while operating the power plants in power cycling mode.
Multivariable statistical analyses, including Principal Component (PCA), cluster, and Fischer Discriminant Analysis (FDA) were used to characterize the leak occurrence. Normal and operational states with steam leaks were provided in the original process datasets. These datasets were split into two different groups for training and validation purposes. The data were sorted chronologically, and every third observation was assigned to training the Discriminant Function Model (DFM) while the rest were reserved for validation. PCA was used to reduce dimensionality of the original datasets. Canonical and FDA analyses were used to investigate the relationship between process variables. The outcome of the analyses revealed that nearly 35,000 observations were classified correctly; less than 0.05% of total observations were misclassified to be leaking, i.e. both false positives and false negatives.
Extending Life Expectancy of La Esmeralda Reservoir: A Bet to Support Colombia’s Future Energy Demand
Authors: del Río David A. , Moffett Hugo , Nieto-Londoño César , Vásquez Rafael E. , Escudero-Atehortúa Ana 
Published: October 2020

Abstract
This work addresses the strategy of AES Corporation (AES Chivor) in order to extend the life of La Esmeralda reservoir to support Colombia’s future energy demand. Chivor Hydropower Plant entered into service in 1978 and has a capacity of 1000 MW, 8 % of Colombia’s demand. It is first described how the Colombian electricity energy mix is composed. Then, La Esmeralda reservoir, which is used by Chivor for power generation, is described; sediment management plans and maintenance costs for equipment and infrastructure are addressed. Then, sediment dynamics studies that have been done in order to determine life expectancy of La Esmeralda reservoir are listed. Such studies have been used to execute the Chivor’s Life Extension Project, which considers the modification of intakes as the best option to extend the life of the reservoir for at least 50 years, among several alternatives that were evaluated by a panel of international experts. This represents a challenge from the engineering point of view, and the project will be shown as a successful example for a country with such dependence on hydropower generation. Modernizing existing infrastructure without affecting the operation, as in this case, is crucial to show how a sustainable sediment management plan and technological development are necessary to extend life of hydropower generation projects, and to help meeting energy demand in a sustainable way for countries such as Colombia with a growing economy.
A Take on Wake Modeling of Turbines Based on Deep Learning
Authors: Ziaei Dorsa , Goudarzi Navid 
Published: October 2020

Abstract
Analyzing real-world engineering problems such as wake modeling of wind/ocean current turbines are known to be complex and challenging. The multivariable nature of these problems requires either the implementation of computational analyses under certain simplifying assumptions or conducting experiments for a limited number of scenarios. Hence, there is always several fundamental features missed in understanding the key players in determining the complex turbulent velocity fields within the wake of turbines. It becomes more critical when studying the optimization of wind/ocean renewable farms with more than one turbine to determine the true power density or cost of energy.
Machine learning (ML) algorithms suggest promising complementary solutions to the existing physics-based (e.g. wind farm wake modeling) techniques. Implementation of conventional ML algorithms that require long-term historical data is either not feasible in many real-case applications or very expensive and time-consuming. Moreover, there are often infinite features in dataset with complex relation between them. It makes the tasks of feature selection and model tuning more challenging. In this work, a cross-domain study of physics and ML models is performed to show the need of integration of these domains. The key achievement of this work is two-fold: first, suggesting a group of emerging generative models (e.g. Generative Adversarial Networks) in the wake modeling domain; second, reducing the computational cost by demanding either smaller or no simulation dataset.
Analysis of Current Hybrid-Electric Automobile Drivetrains and Proposal of an Alternative Powertrain
Authors: Ahn Andrew , Welles Thomas S. , Akih-Kumgeh Benjamin 
Published: October 2020

Abstract
Byproducts of fossil fuel combustion contribute to negative changes in the global climate. Specifically, emissions from automobiles are a major source of greenhouse gas pollution. Efforts to minimize these harmful emissions have led to the development and sustained improvement of hybrid drivetrains in automobiles. Despite many advancements, however, hybrid systems still face substantial challenges which bear on their practicality, performance, and competitive disadvantage in view of the low cost of today’s traditional internal combustion engines. These imperfections notwithstanding, hybrid electric vehicles have the potential to play significant roles in the future as cleaner transportation solutions. Actualization of this potential will depend on the ability of hybrid-electric vehicles to minimize their disadvantages while increasing their positive features relative to traditional combustion engines. This research investigates current hybrid electric architectures in automobiles with the aim of suggesting an alternative, more efficient hybrid configuration that utilizes current technology. This is completed by utilizing an iterative design process to compare how various components of existing hybrids can be combined and/or improved to develop a single, efficient and cohesive system that performs comparably to or surpasses existing ones in fuel efficiency and low emissions in all driving conditions. A critical and comparative analysis is provided based on current hybrid-electric vehicle architectures as well as a plausible alternative.
Randomised controlled pilot trial comparing low dose and very low- dose microdrop administration of phenylephrine and cyclopentolate for retinopathy of prematurity eye examinations in neonates
Authors: Kremer Lisa Jean , Broadbent Roland , Medlicott Natalie , Sime Mary Jane , McCaffrey Frances , Reith David M 
Published: October 2020

AimsTo determine ifVery low dose mydriatic eye microdrop regimen sufficiently dilates the pupil (above 4.1 mm) compared with the currently used low dose mydriatic eye microdrop regimen.Cardiovascular, gastrointestinal and respiratory adverse effects occur following eye drop instillation.MethodsSeventeen premature infants were recruited into this prospective, randomised controlled pilot trial in January 2017 to November 2018. Data were collected from the single-centre Neonatal Intensive Care Unit, Dunedin Hospital, New Zealand. The inclusion criteria were birth weight less than 1500 g or gestational age less than 31 weeks, or any premature infant requiring red reflex testing. Infants were randomised to receive either phenylephrine 1% or 0.5% and cyclopentolate 0.2% or 0.1%, 1 microdrop in both eyes. Efficacy outcome measures were pupil size at retinopathy of prematurity eye examination (ROPEE) and ophthalmologist rating of ease of screen.ResultsAll participants had sufficient pupillary dilation for a successful ROPEE. Ophthalmologists rated the ROPEE as easy for 90% of all examinations. Pupil dilation measurements at the time of examination, mean±SD, 4.8±0.2 (95% CI 4.5 to 5.2) mm for treatment A and 5±0.2 (95%CI 4.6 to 5.4) mm for treatment B (p=0.61). There were no statistically significant differences between the groups for safety data.ConclusionsVery low dose microdrop administration of phenylephrine and cyclopentolate appears to be effective at sufficiently dilating the neonatal pupil for ROPEEs. Low dose and very low dose microdrop mydriatic regimens may also reduce the risk of unwanted adverse effects associated with these medicines.Trial registration numberAustralian New Zealand Clinical Trials Registry (reference ACTRN12616001266459p).
Mechanisms of acute ankle syndesmosis ligament injuries in professional male rugby union players: a systematic visual video analysis
Authors: Delahunt Eamonn , Farrell Garreth , Boylan Andrew , Kerin Fearghal , Tierney Peter , Hogan Hugh , Boreham Colin 
Published: October 2020

Background
The mechanisms of acute ankle syndesmosis ligament injuries in professional rugby union are not well understood.

Aim
To describe the mechanisms of acute ankle syndesmosis ligament injuries in male professional rugby union players using systematic visual video analysis.

Methods
All time-loss acute ankle syndesmosis ligament injuries identified via retrospective analysis of the Leinster Rugby injury surveillance database across the 2013/2014 to 2017/2018 seasons were considered as potentially eligible for inclusion. Three Chartered Physiotherapists (analysts) independently assessed all videos with a final consensus meeting convened to describe the injury mechanisms. One of the analysts developed a qualitative description of each injury mechanism.

Results
Thirteen acute ankle syndesmosis injuries were included in this study. The most common biomechanical presentation of the injured limb was characterised by hip flexion, knee flexion, knee valgus, ankle dorsiflexion, pronation and external rotation of the foot. Six of the included injuries (46%) were the result of an external load application to the injured limb (ie, direct contact injuries). In the other seven instances (54%), the injury was the result of a collapse of the injured player’s body mass over the injured ankle joint, while tackling or being tackled, without direct contact to the injured limb (ie, indirect contact injuries).

Conclusion
Injuries incurred while tackling were exclusively the result of suboptimal tackle mechanics. A majority of injuries incurred while being tackled involved a posterior tackle, which often resulted in a posterior collapse of the injured player’s centre of mass over a fixed externally rotated foot.
Village-level climate and weather variability, mediated by village-level crop yield, is associated with linear growth in children in Uganda
Authors: Ssentongo Paddy , Ba Djibril M , Fronterre Claudio , Chinchilli Vernon M 
Published: October 2020

IntroductionTo investigate total annual precipitation, precipitation anomaly and aridity index in relation to linear growth in children under 5 in Uganda and quantify the mediating role of crop yield.MethodsWe analysed data of 5219 children under 5 years of age who participated in the 2016 Uganda Demographic and Health Survey. Annual crop yield in kilograms per hectare for 42 crops at a 0.1° (~10 km at the equator) spatial resolution square grid was obtained from the International Food Policy Research Institute. Normalised rainfall anomaly and total precipitation were derived from the African Rainfall Estimation Algorithm Version 2 product. Linear regression models were used to associate total annual precipitation and anomalies with height-for-age z-scores and to explore the mediating role of crop yield qualitatively. The intervening effects were quantitatively estimated by causal mediation models.ResultsTwenty-nine per cent of children were stunted (95% CI 28% to 31%). After adjusting for major covariates, higher total annual precipitation was significantly associated with increasing height-for-age z-scores. At the mean, an increase of 1 standard deviation in local annual rainfall was associated with a 0.07-point higher z-score. Aridity index and precipitation anomaly were not associated with height-for-age z scores in altitude-adjusted models. Crop yields of nuts, seeds, cereals and pulses were significant mediating factors. For instance, 38% of the association between total annual precipitation with height-for-age z-scores can be attributed to the yield of sesame seeds.ConclusionsHigher total annual precipitation at the village-level was significantly associated with higher height-for-age z-scores among children in Uganda. This association can be partially explained by higher crop yield, especially from seeds and nuts. This study suggests that more attention should be paid to villages with lower annual rainfall amounts to improve water availability for agriculture.
Interdisciplinary development and evaluation of a novel needle guide for ultrasound-guided lumbar epidural placement
Authors: Singla Rohit , Burlinson Clare , Honigmann Simon , Abolmaesumi Purang , Chau Anthony , Rohling Robert 
Published: October 2020

Purpose
A solution for real-time, ultrasound-guided, central neuraxial blockade placement remains elusive. A device that enables single-operator neuraxial placement while simultaneously visualising the spinal anatomy and needle trajectory may improve patient safety. We engineered a novel needle guide, the EpiGuide two dimensional (2D), and compared prepuncture insertion sites as located using the guide versus standard manual palpation.

Methods
Interdisciplinary collaboration between engineers and obstetric anaesthesiologists and multiple iterative refinement led to the EpiGuide 2D, a prototype multichannel needle guide for ultrasound transducers. Following ethics committee approval, 22 healthy adult participants were recruited to undergo prepuncture lumbar epidural placement using the guide. The primary outcome was accuracy, defined as the percentage of successful placements of prepuncture needle insertion sites within the manually palpated intervertebral space. The secondary outcome was distance between the prepuncture insertion sites guided by the EpiGuide 2D versus by sites guided by manually palpation.

Results

Mean (SD) body mass index of participants was 22.6 (2.1) kg/m
2
. The success rate of selecting a prepuncture site within the manually palpated intervertebral space using EpiGuide 2D was 95.5% (42 of 44 attempts). Of the failed sites, the mean (SD) distance to the intervertebral space was 1.3 (0.3) mm in the caudal direction. The mean (SD) distance between EpiGuide 2D sites and palpated sites was 3.6 (2.0) mm.

Conclusion
The EpiGuide 2D, jointly developed between engineers and anaesthesiologists, was found to be as accurate as manual palpation in placing a prepuncture site within the intervertebral space.
Diagnostic accuracy of the magnetocardiograph for patients with suspected acute coronary syndrome
Authors: Goodacre Steve , Walters Stephen J , Qayyum Hasan , Coffey Frank , Carlton Edward , Coats Timothy , Glazebrook William , Unitt Lynda 
Published: October 2020

BackgroundWe aimed to estimate the diagnostic accuracy of the VitalScan magnetocardiograph (MCG) for suspected acute coronary syndrome (ACS).MethodsWe undertook a prospective cohort study evaluating the diagnostic accuracy of the MCG in adults with suspected ACS. The reference standard of ACS was determined by an independent adjudication committee based on 30-day investigations and events. The cohort was split into a training sample, to derive the MCG algorithm and an algorithm combining MCG with a modified Manchester Acute Coronary Syndrome (MACS) clinical probability score, and a validation sample, to estimate diagnostic accuracy.ResultsWe recruited 756 participants and analysed data from 680 (293 training, 387 validation), of whom 96 (14%) had ACS. In the training sample, the respective area under the receiver operating characteristic (AUROC) curves were the following: MCG 0.66 (95% CI 0.58 to 0.74), MACS 0.64 (95% CI 0.54 to 0.73) and MCG+MACS 0.70 (95% CI 0.63 to 0.77). MCG specificity was 0.16 (95% CI 0.12 to 0.21) at the threshold achieving acceptable sensitivity for rule-out (>0.98). In the validation sample (n=387), the respective AUROCs were the following: MCG 0.56 (95% CI 0.48 to 0.64), MACS 0.69 (95% CI 0.61 to 0.77) and MCG+MACS 0.64 (95% CI 0.56 to 0.72). MCG sensitivity was 0.89 (95% CI 0.77 to 0.95) and specificity 0.15 (95% CI 0.12 to 0.20) at the rule-out threshold. MCG+MACS sensitivity was 0.85 (95% CI 0.73 to 0.92) and specificity 0.30 (95% CI 0.25 to 0.35).ConclusionThe VitalScan MCG is currently unable to accurately rule out ACS and is not yet ready for use in clinical practice. Further developmental research is required.
A life course approach to elucidate the role of adiposity in asthma risk: evidence from a Mendelian randomisation study
Authors: Au Yeung Shiu Lun , Li Albert Martin , Schooling C Mary 
Published: October 2020

BackgroundAdiposity is associated with asthma although studies do not usually explore the inter-related role of childhood and adult adiposity in asthma risk using a life course perspective.MethodsWe conducted a Mendelian randomisation (MR) study using genetic instruments for childhood body mass index (BMI) (n=47 541), childhood obesity (n=29 822) and adult BMI (n=681 725) applied to the UK Biobank (n=401 837), with validation in a genome-wide association study of asthma (GABRIEL, n=5616). We used inverse variance weighting and other sensitivity analyses to examine the relationship between adiposity and asthma risk. We assessed mediation using multivariable Mendelian randomisation (MVMR) analysis.ResultsChildhood BMI was related to asthma in the UK Biobank (OR 1.10 per SD increase, 95% CI 0.99 to 1.22). Adult BMI was associated with asthma risk (OR 1.33 per SD increase, 95% CI 1.25 to 1.43). Analyses in GABRIEL gave directionally consistent results but with wide CI. The relationship between childhood obesity and asthma risk was less clear in both data sources. MVMR suggested the relation of childhood BMI with asthma risk was largely mediated via adult BMI.ConclusionAdiposity in childhood likely cause asthma, but the effect is primarily mediated via adult BMI.