bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro-Computed Tomography Pore-Scale Study on Natural Convection in a Cubic Cavity Filled With Complex Porous Medium
Authors: Wang Xu , Li Peng , Xu Anyi , Liu Zhenyu 
Published: September 2020

Abstract
A pore-scale numerical simulation was carried out in this study to predict the natural convection in a cubic cavity filled with reconstructed porous medium using lattice Boltzmann Method (LBM). The computational porous domain was established with the micro-computed tomography technique. The natural convection phenomena were predicted with the pore-scale simulation for different thermal boundary conditions and fluid thermal properties. The results show that the natural convection in the present porous domain is more obvious as the side wall is heated compared to that as the bottom wall is heated. The existence of porous structure suppresses the natural convection in the cubic cavity. As Rayleigh number increases, the natural convection in the porous domain is enhanced accordingly. The heat flux distribution on the porous structure surface varies intensively due to the complex flow characteristic in the small pore spaces. The numerical approach presented in this study is to provide a promising solution that can simulate pore-scale natural convection in porous medium and can be further extended for the development of field-scale model for transport processes in porous medium.
Thermally Developing Laminar Liquid Flow and Heat Transfer in Microtubes at Slip Regime
Authors: Gong Wenchi , Shen Jun , Dai Wei 
Published: September 2020

Abstract
Heat transfer enhancement is usually accompanied by an increase in pressure drop. With the implementation of the various drag reduction methods, the researches and applications of DR methods in heat transfer enhancement have attracted more and more attention. The research on drag reduction by introducing superhydrophobic surface shows that the slip regime plays an important role in drag reduction. This study numerically investigated thermally developing laminar liquid flow and heat transfer in microtubes at slip regime, with a hydraulic diameter of 200 μm, a constant heat flux of 105 W/m2, a Re of 100 and a slip length ls ranging from 2 μm to 20 μm. The dimensionless thermal entrance length increases with the increased slip length. The results show that microtube with slip boundary has the larger local Nusselt number and a longer thermal entrance length compared with available experimental data of non-slip boundary. Local and average Nusselt numbers are obtained, and start high and rapidly decrease with the increased dimensionless axial distance. Meanwhile, Nusselt number increases with the increased slip length. The correlations of the dimensionless thermal entrance length and local Nusselt number have mean absolute relative deviation of no more than 0.12% and 1.53% respectively, which can be used to optimize microchannel heat sinks.
Transient Performance of Fixed-Bed Regenerators for Energy Recovery in Building Applications
Authors: Ramin Hadi , Krishnan Easwaran N. , Annadurai Gurubalan , Simonson Carey J. 
Published: September 2020

Abstract
A small-scale test facility is developed to determine the sensible effectiveness of a Fixed-Bed Regenerator (FBR) and the results are used to validate a numerical model. The numerical and experimental results for quasi-steady-state conditions are in a good agreement within the experimental uncertainty bounds. At quasi-steady-state condition, the outlet temperature of FBR varies with time but cyclically repeats itself; this is an important difference between FBR (regenerator) and recuperator heat exchangers. The outlet temperature of recuperator heat exchangers reaches a constant value during the steady-state operation. The quasi-steady-state temperature profile is used to determine the sensible effectiveness of FBRs.
However, FBRs undergo several cycles to reach the quasi-steady-state condition. The prediction of the duration of the transient duration of FBR is important for performance testing that could save money and time. CSA (Canadian Standards Association) recommends operating FBR for at least one hour to achieve a quasi-steady-state condition. This paper addresses the heat transfer behavior of FBRs during their transient operation. The initial transient cycles depend on the cycle period of FBR, air flow rate and the thermal condition of the exchanger at the beginning of the test. The small-scale FBR test facility is used to study the transient behavior of FBRs and this is the main focus of this paper.
The temperature profile during the transient condition of FBR is obtained and the results are compared with the numerical model. The effects of the mass flow rate of air and the cycle duration on the transient period of FBR are studied. The results show that FBR reaches a quasi-steady state operation in less than 30 minutes. The results will be useful for understanding the time required for performance testing, which will reduce the cost and time of each test.
Furnace Design for Improved Exhaust Gas Circulation and Heat Transfer Efficiency
Authors: Brimmo Ayoola T. , Ali Mohamed I. Hassan 
Published: September 2020

Abstract
In the aluminum production industry, metal furnaces are operated by diffusion flame over the metal surface to maintain the aluminum metal at the set point temperature for alloying and casting. Heat is transferred from the flame and its exhaust gases to the metal surface via radiation and convection. The exhaust gases leaves through the furnace’s chimney carrying a significant amount of waste heat to the atmosphere. Furnace efficiency could be improved by enhancing the heat transfer inside the furnace. In this study, a validated full-scale 3-D CFD model of a natural gas fired aluminum furnace is developed to investigate the effect of flue gas ventilation configurations and burner operating conditions on the heat transfer inside the furnace. Onsite measurements are carried out for the fuel and airflow rates as well as flue gas temperature. Four flue ventilation configurations are considered with eight furnace’s operation modes. The flue-gas’s waste-heat varies from 49–58%, with the highest value occurring at the high-fire operating mode. This indicates a significant room for improvement in the furnace performance. Results suggest that a symmetrical positioning of the exhaust duct favors effective exhaust gas circulation within the furnace and hence, increases hot-gases’ heat-transfer effectiveness inside the furnace. These results provide some guidelines for optimal aluminum reverberatory furnace designs and operation.
On Classification and Quantification of Sensory Parameters in Judging Mirror Surface: Appearance of a Turned Aluminum Alloy Surface
Authors: Ihara Motohiro , Yamaji Iwao , Matsubara Atsushi 
Published: September 2020

Abstract
Machined surfaces are judged to determine machining conditions. Quantitative parameters like surface roughness and sensory parameters, such as glossiness, cloudiness, sense of discomfort and so on, of the tester, are used as the criteria. Sensory parameters can be dominant especially in judging mirror surfaces with low surface roughness. Such parameters and their representations, however, depend on each tester’s experience. Consequently, we cannot quantitatively evaluate mirror surfaces considering human sensory parameters. In this research, we aim to classify and quantify sensory parameters, and evaluate mirror surfaces quantitatively. In this report, We analyzed the appearance of the turned surface of an aluminum alloy (A2017) under different cutting conditions, focusing on ‘glossy’ and ‘cloudy’ surfaces. Two testers visually inspected the surfaces. The surface shape was measured with a surface roughness measuring device. Additionally, images of the surfaces were obtained with two different illumination configurations. Consequently, it was expected that fine irregularities on the surface influenced the surface appearance and images. Furthermore, the distribution of the light reflection coefficient was calculated from the measured shape data, based on the Beckmann’s theory on the scattering of electromagnetic waves. Consequently, the sensory evaluation, the surface images and the calculation of the light reflection coefficient provided the same trends and conclusions.
Behavior Modeling for Product Design Support Focusing on Topological Information of Components
Authors: Hatano Itsuki , Wakamatsu Hidefumi , Morinaga Eiji 
Published: September 2020

Abstract
In recent years, with globalization in industry, there is a concern about increase of defects caused by using products in unexpected ways. To solve this problem, a method to predict such defects in a product in advance in the design stage has been proposed, in which behavior of a product and physical phenomena caused by a way of usage are represented by Petri net. However, in order to achieve a more accurate prediction, it is necessary to consider topological information about components of a product. In this research, we aim to represent topological information about elements of an electric circuit, and to make it possible to detect failures in cooperation with the method of the previous research. By modeling each element of an electrical circuit by Petri net and connecting them each other, it is possible to build a model that represents topological information about the circuit, and it can be checked whether there is a closed circuit and which element the current flows through. In addition, by reflecting the information about the circuit to the conventional model, more accurate failure detection can be performed. The fundamental effectiveness of the method was shown by case studies using an example circuit.
Application of MOSA Algorithm in Gleeble Testing Model Updating
Authors: Xu Dong , Zhou Kai , Tang J. 
Published: September 2020

Abstract
This research concerns the parametric identification of Johnson-Cook constitutive model which is frequently used to describe the mechanical behavior of metal material at high temperature. An improved multi-objective simulated annealing (MOSA) algorithm is introduced to update Johnson-Cook model based on Gleeble testing data for Steel T24. Our case study produces Pareto solutions ranked by the error corresponding to each parameter to be optimized. This algorithm improves the previous methods and yields a more suitable solution corresponding to the actual situation.
Test–Retest Reliability of activPAL in Measuring Sedentary Behavior and Physical Activity in People With Type 2 Diabetes
Authors: Alothman Shaima , Hoover Jeffrey C. , Alshehri Mohammed M. , Alenazi Aqeel M. , Wick Jo , LeMaster Joseph , Rucker Jason , Kluding Patricia M. 
Published: September 2020

Background: To investigate how changes in sedentary behavior relate to health outcomes, it is important to establish the test–retest reliability of activity monitors in measuring habitual sedentary behavior in people with type 2 diabetes (T2D) as a prerequisite for interpreting this information. Thus, the authors’ objective was to examine the test–retest reliability of a common activity monitor (activPAL™) in measuring sedentary behavior and physical activity in people with T2D. Methods: Sedentary-time, standing-time, stepping-time, step-count, and sit-to-stand transitions were obtained from two 7-day assessment periods separated by at least 1 week. Test–retest reliability was determined with the intraclass correlation coefficient (ICC) to compare sedentary and activity measures between the 2 time points. Results: A total of 30 participants with self-reported T2D completed the study (age 65 [6] y, 63% women, body mass index 33.3 [5] kg/m2). High test–retest reliability was found for sedentary-time (ICC = .79; 95% confidence interval [CI], .61–.89) and standing-time (ICC = .74; 95% CI, .53–.87). Very high test–retest reliability was found for stepping-time (ICC = .90; 95% CI, .81–.95), step-count (ICC = .91; 95% CI, .83–.96), and sit-to-stand transitions (ICC = .90; 95% CI, .79–.95). Conclusion: The activPAL™ device showed high to very high test–retest reliability in measuring all tested activity categories in people with T2D.
Modeling glacier extents and equilibrium line altitudes in the Rwenzori Mountains, Uganda, over the last 31,000 yr
Authors: Doughty* Alice M. , Kelly Meredith A. , Russell James M. , Jackson Margaret S. , Anderson Brian M. , Chipman Jonathan , Nakileza Bob , Dee Sylvia G. 
Published: September 2020

ABSTRACT
Mountain glacier moraine sequences and their chronologies allow us to evaluate the timing and climate conditions that underpin changes in the equilibrium line altitudes (ELAs), which can provide valuable information on the paleoclimatology of understudied regions such as tropical East Africa. However, moraine sequences are inherently discontinuous, and the precise climate conditions that they represent can be ambiguous due to the sensitivity of mountain glaciers to temperature, precipitation, and other environmental variables. Here, we used a two-dimensional (2-D) ice-flow and mass-balance model to simulate glacier extents and ELAs in the Rwenzori Mountains in East Africa over the past 31,000 yr (31 k.y.), including the Last Glacial Maximum (LGM), late glacial period, and the Holocene Epoch. We drove the glacier model with two independent, continuous temperature reconstructions to simulate possible glacier length changes through time. Model input paleoclimate values came from branched glycerol dialkyl glycerol tetraether (brGDGT) temperature reconstructions from alpine lakes on Mount Kenya for the last ~31 k.y., and precipitation reconstructions for the LGM came from various East African locations. We then compared the simulated fluctuations with the positions and ages (where known) of the Rwenzori moraines. The simulated glacier extents reached within 1.1 km of the dated LGM moraines in one valley (93% of the full LGM extent) when forced by the brGDGT temperature reconstructions (maximum cooling of 6.1 °C) and a decrease in precipitation (−10% than modern amounts). These simulations suggest that the Rwenzori glaciers required a cooling of at least 6.1 °C to reach the dated LGM moraines. Based on the model output, we predict an age of 12–11 ka for moraines located halfway between the LGM and modern glacier extents. We also predict ice-free conditions in the Rwenzori Mountains for most of the early to middle Holocene, followed by a late Holocene glacier readvance within the last 2000 yr.
BCG skin reactions by 2 months of age are associated with better survival in infancy: a prospective observational study from Guinea-Bissau
Authors: Schaltz-Buchholzer Frederik , Berendsen Mike , Roth Adam , Jensen Kristoffer Jarlov , Bjerregaard-Andersen Morten , Kjær Sørensen Marcus , Monteiro Ivan , Aaby Peter , Stabell Benn Christine 
Published: September 2020

IntroductionReceiving Bacille Calmette-Guérin (BCG)-Denmark vaccine at birth has been associated with ~40% reductions in all-cause neonatal mortality. We evaluated determinants of BCG skin reaction characteristics by age 2 months and tested the association with subsequent mortality.MethodsProspective observational study amalgamating five trials providing BCG-at-birth that were conducted between 2002 and 2018 in Guinea-Bissau. The reaction status and size were evaluated at home-visits by 2 months of age among 6012 neonates; mortality from 2 to 12 months was assessed at subsequent visits. Reaction determinants were evaluated by binomial regression providing risk ratios (RRs). In Cox-models providing adjusted mortality rate ratios (aMRRs), we assessed the association between (1) having a 2-month reaction (yes/no) and (2) reaction size tertiles and subsequent all-cause mortality risk. A subgroup had their BCG reaction evaluated and were bled at age 4 weeks; their samples underwent in vitro analysis for specific and non-specific cytokine responses.ResultsThe BCG strain was the main determinant for developing a 2-month reaction and the reaction size: the BCG-Russia/BCG-Denmark RR for large-reaction was 0.38 (0.30–0.47) and the BCG-Russia/BCG-Japan RR was 0.61 (0.51–0.72). 5804 infants (96.5%) were reactors by age 2 months; 208 (3.5%) were non-reactors. The 2–12 months mortality risk was 4.8% (10/208) for non-reactors, 2.9% (64/2213) for small reactors, 1.8% (30/1710) for medium reactors and 0.8% (15/1881) for large reactors. The reactor/non-reactor aMRR was 0.49 (0.26–0.95) and there was a linear trend of decreasing mortality with increasing reaction size (p for trend <0.001). BCG reactors had higher 4-week specific and non-specific cytokine responses, responses that were highest among those with large reactions.ConclusionAmong BCG-vaccinated infants, having a BCG skin reaction by age 2 months was associated with markedly better survival, as was the reaction size. Our findings thus support that BCG has substantial effects on all-cause mortality. Emphasising at-birth vaccination with immunogenic BCG strains and revaccinating non-reactors and small reactors could have major public health benefits.Trial registration numbersNCT00146302,NCT00168610,NCT00625482,NCT01989026andNCT02447536.
PP11  Defining major trauma in the hyper acute setting
Authors: Thompson Lee , Hill Michael , McMeekin Peter , Shaw Gary 
Published: September 2020

BackgroundPre-hospital trauma is complex and challenging, with limited clinical exposure for clinicians. In addition, there is no standardised definition for major trauma, and retrospective scores commonly quantify injury severity, such as the injury severity score. This qualitative study aimed to explore the pre-hospital perspectives of major trauma and how pre-hospital trauma care providers define major trauma.MethodThree focus groups of 40–60 minutes duration were conducted with paramedics, ambulance technicians, police, firefighters and emergency dispatchers. Digital recordings were transcribed verbatim, coded and reviewed to identify emerging themes. Constant comparison was undertaken throughout and codes identified for qualitative thematic analysis.ResultsThree overarching themes emerged: clinician factors, patient factors and situational factors. Clinician factors highlighted issues of experience and exposure (or lack of) to major trauma and its relationship to clinical concern, communication issues and the complex nature of pre-hospital trauma. Patient factors identified deranged physiology, actual injuries, life changing trauma, potential need for surgical intervention and rehabilitation as defining major trauma. These variables are often complicated by the extremities of age as well as previous medical history and medications. The situational factors identified that every traumatic encounter is unique, requiring bespoke management where high and low energy mechanisms of injury should be considered.ConclusionBased on the analysis of the focus groups, a working pre-hospital definition is: Any injury (or injuries) that have the potential to be life-threatening or life-changing, including those sustained from low energy mechanisms in people rendered vulnerable by extremes of age, comorbidities or frailty, resulting in significant physiological compromise (haemodynamic instability, reduced consciousness, respiratory compromise) and/or significant anatomical abnormality that may require immediate intervention.
PP12  A survey-based evaluation of the impact of menopause transition on female ambulance staff in one UK ambulance service
Authors: Foster Theresa , Prothero Larissa S , Winterson Debra 
Published: September 2020

BackgroundMenopausal symptoms can have a significant impact on workplace attendance and performance, yet limited evidence regarding the menopause transition in the emergency services exists. The aim of this study was to explore work and personal impacts of the menopause on female staff in the ambulance setting.MethodsA purpose-designed, online 20-question survey, based on the British Menopause Society Survey (2016), was developed to understand menopausal symptoms and their impact on female staff in one UK ambulance service. Disseminated during July 2019, it resulted in a convenience sample of 522 responses (22% of female workforce), which were analysed using quantitative (descriptive) and qualitative (thematic) approaches.ResultsTypically, respondents were either pre-menopausal (33%; n=171) or peri-menopausal (24%; n=126). Approximately one third (31%; n=161) were menopausal or post-menopausal. Over half worked in operational emergency service delivery (58%; n=301), and typically worked shifts/unsocial hours (75%; n=391). For those who had experienced menopause symptoms (64%; n=336), wide-ranging symptoms were reported: tiredness/low energy levels, difficulty sleeping/insomnia, mood changes (including anxiety and depression), musculoskeletal problems, and hot flushes and/or night sweats were most common. The majority (61%; n=205) stated they had not expected the symptoms they experienced, which had impacted on their well-being (51%; n=171); work life (45%; n=151), some requiring time off work (21%; n=71); and home life (44%; n=148). Only 12% (n=40) of respondents felt supported at work. Of most concern to respondents was lack of awareness of menopause symptoms, and their impact throughout the service, in particular those in managerial roles and male staff.ConclusionsAll women will experience the menopause and will work through and beyond this life phase. For those who experience menopausal symptoms, the impact can be significant. Yet menopause awareness in the ambulance service is limited and there is clear scope for initiatives for improved staff support and well-being.
03  What factors affect paramedics’ involvement of people with dementia in decisions affecting their care? A qualitative study
Authors: Choonara Esme 
Published: September 2020

BackgroundParamedics are frequently called to people with dementia due to high rates of co-morbidities and complex needs, but decision making can be challenging due to lack of information or difficulties in assessment. Best-practice dementia care should be holistic and involve people with dementia in decisions as far as possible. A small number of qualitative studies have looked at paramedics’ decision-making in relation to dementia, but these studies have not specifically investigated the involvement of people with dementia in decisions. This study aimed to explore how paramedics make decisions when attending people with dementia, with a particular focus on understanding the factors that impact on whether, how, and to what degree paramedics involve people with dementia in decisions about their care.MethodsA generic qualitative research approach was used, informed by social constructivism and by the researcher’s commitment to the concept of ‘personhood’ in dementia care. Data were collected through semi-structured individual interviews with seven paramedics, each lasting between 40 and 80 minutes. The interviews were recorded and transcribed verbatim and subsequently analysed using thematic analysis.ResultsFour themes were identified that all touched on challenges to delivering person-centred care for people with dementia. Themes identified were: 1. Paramedics’ differing approaches to assessing capacity and making best interest decisions. 2. Communication and developing a rapport. 3. Interconnections with others important to the person with dementia. 4. The impact of paramedics’ values and attitudes.ConclusionThe involvement of people with dementia is sometimes limited by medical, social or clinician-dependent factors. This study highlights how paramedics’ values and communication skills influence their interactions with people with dementia. As the paramedic role evolves, there is an opportunity to embed person-centred care in practice and to ensure that education equips paramedics with the skills and ethical frameworks needed to deliver high quality dementia care.