bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Study of Enhanced Oil Recovery Using In Situ Oxy-Combustion in a Porous Combustion Tube
Authors: Hamdy Mohamed , Mahmoud Mohamed , Aladeb Olakane , Mokheimer Esmail M. A. 
Published: June 2020

AbstractIn situ combustion (ISC) in a one-dimensional combustion porous tube has been modeled numerically and presented in this article. The numerical model has been developed using the cmg stars (2017.10) software and it was used to model especial cases for validation against published experimental data. A comprehensive chemical reaction scheme has been developed and used to simulate the ISC process in the lab scale. Moreover, co-injection of oxygen with carbon dioxide (O2/CO2); and co-injection of enriched air (O2/N2) have been further investigated. In the case of using (O2/N2) as an oxidizer, increasing the oxygen ratio from 21% to 50% leads to increasing the oil recovery factor from 31.66% to 66.8%, respectively. In the case of using (O2/CO2) as an oxidizer, increasing the oxygen ratio from 21% to 50% leads to increasing the oil recovery factor from 35.77% to 70.3%, respectively. It was found that the co-injection of (O2/CO2) gives higher values of the oil recovery factor compared with that given when oxygen-enriched air (O2/N2) is injected for ISC. The change in the produced cumulative hydrogen and hydrogen sulfide is considered small whether using (O2/CO2) or (O2/N2) as an oxidizer.
Data-Driven Models to Predict Hydrocarbon Production From Unconventional Reservoirs by Thermal Recovery
Authors: Lee Kyung Jae 
Published: June 2020

AbstractIn the numerical simulations of thermal recovery for unconventional resources, reservoir models involve complex multicomponent-multiphase flow in non-isothermal conditions, where spatial heterogeneity necessitates the huge number of discretized elements. Proxy modeling approaches have been applied to efficiently approximate solutions of reservoir simulations in such complex problems. In this study, we apply machine learning technologies to the thermal recovery of unconventional resources, for the efficient computation and prediction of hydrocarbon production. We develop data-driven models applying artificial neural network (ANN) to predict hydrocarbon productions under heterogeneous and unknown properties of unconventional reservoirs. We study two different thermal recovery methods—expanding solvent steam-assisted gravity drainage for bitumen and in-situ upgrading of oil shale. We obtain training datasets by running high-fidelity simulation models for these two problems. As training datasets of ANN models, diverse input and output data of phase and component productions are generated, by considering heterogeneity and uncertainty. In the bitumen reservoirs, diverse permeability anisotropies are considered as unknown properties. Similarly, in the oil shale reservoirs, diverse kerogen decomposition kinetics are considered. The performance of data-driven models is evaluated with respect to the position of the test dataset. When the test data is inside of the boundary of training datasets, the developed data-driven models based on ANN reliably predict the cumulative productions at the end of the recovery processes. However, when the test data is at the boundary of training datasets, physical insight plays a significant role to provide a reliable performance of data-driven models.
Probing the Effects of NOx and SOx Impurities on Oxy-Fuel Combustion in Supercritical CO2: Shock Tube Experiments and Chemical Kinetic Modeling
Authors: Rahman Ramees K. , Barak Samuel , (Raghu) Manikantachari K.R.V. , Ninnemann Erik , Hosangadi Ashvin , Zambon Andrea , Vasu Subith S. 
Published: June 2020

Abstract
The direct-fired supercritical carbon dioxide cycles are one of the most promising power generation methods in terms of their efficiency and environmental friendliness. Two important challenges in implementing these cycles are the high pressure (300 bar) and high CO2 dilution (&gt;80%) in the combustor. The design and development of supercritical oxy-combustors for natural gas require accurate reaction kinetic models to predict the combustion outcomes. The presence of a small amount of impurities in natural gas and other feed streams to oxy-combustors makes these predictions even more complex. During oxy-combustion, trace amounts of nitrogen present in the oxidizer is converted to NOx and gets into the combustion chamber along with the recirculated CO2. Similarly, natural gas can contain a trace amount of ammonia and sulfurous impurities that get converted to NOx and SOx and get back into the combustion chamber with recirculated CO2. In this work, a reaction model is developed for predicting the effect of impurities such as NOx and SOx on supercritical methane combustion. The base mechanism used in this work is GRI Mech 3.0. H2S combustion chemistry is obtained from Bongartz et al. while NOx chemistry is from Konnov. The reaction model is then optimized for a pressure range of 30–300 bar using high-pressure shock tube data from the literature. It is then validated with data obtained from the literature for methane combustion, H2S oxidation, and NOx effects on ignition delay. The effect of impurities on CH4 combustion up to 16 atm is validated using NOx-doped methane studies obtained from the literature. In order to validate the model for high-pressure conditions, experiments are conducted at the UCF shock tube facility using natural gas identical mixtures with N2O as an impurity at ∼100 bar. Current results show that there is a significant change in ignition delay with the presence of impurities. A comparison is made with experimental data using the developed model and predictions are found to be in good agreement. The model developed was used to study the effect of impurities on CO formation from sCO2 combustors. It was found that NOx helps in reducing CO formation while the presence of H2S results in the formation of more CO. The reaction mechanism developed herein can also be used as a base mechanism to develop reduced mechanisms for use in CFD simulations.
Utilizing Food Waste Product (Date Tree Seeds) to Enhance the Filtration Characteristics in Water-Based Drilling Fluid System: A Comparative Study
Authors: Al-Hameedi Abo Taleb T. , Alkinani Husam H. , Alkhamis Mohammed M. , Dunn-Norman Shari 
Published: June 2020

AbstractPractically, to regulate filtration characteristics of drilling fluid, non-biodegradable materials used commonly have a high cost with side effects on personnel safety and the environment. Hence, eco-friendly additives are needed as an alternative to replace or at least support the commonly used filtration control agents. This experimental investigation examines the possibility of using date tree seeds’ powder (DTSP), as a new eco-friendly fluid loss agent. Under surface and sub-surface conditions (fresh and aged conditions), experiments were executed utilizing low-temperature and low-pressure (LTLP) and high-temperature and high-pressure (HTHP) American Petroleum Institute (API) filter press to comprehend the influence of DTSP on the seepage loss characteristics. The findings were compared with a commonly utilized chemical additive to regulate filtration characteristics of drilling fluid (low viscosity sodium carboxymethyl cellulose (CMC-LV)). Two concentrations of DTSP and CMC-LV were added separately to a reference fluid (RF) to understand the effect of concentration variations on filtration properties. The findings revealed that both DTSP and CMC-LV significantly improved the filtrate and the filter cake when comparing them with the RF under fresh and aged conditions. The findings for fresh conditions also showed that LTLP filtration measurements for CMC-LV additives had almost similar performance as DTSP additives, while HTHP filtration measurements exhibited that the two concentrations of DTSP additives were marginally better than those of CMC-LV additives. For aged conditions, CMC-LV additives were relatively more efficient than DTSP additives for LTLP filtration control experiments. However, DTSP additives were more efficient in improving the filtration characteristics as compared to CMC-LV additives for HTHP filtration control experiments. These results are in aid of shifting the oil and gas industry from using conventional harmful additives to using unconventional eco-friendly additives. This also helps in transforming unwanted food wastes into valuable commercial products, which can revolutionize the domestic and international industries and create new job opportunities, hence minimizing the total cost of drilling fluid and the wastes disposed to the environment.
Quantifying Engineering Faculty Performance Based on Expectations on Key Activities and Integration Using Flexible Weighting Factors
Authors: Han Hai-Chao , Wan Hung-da , Wang Xiaodu 
Published: June 2020

Abstract
Faculty performance evaluation is an important element of assessment for departments and universities. A quantitative score is often needed for faculty annual evaluation, but its determination is often subjective, and it is hard to incorporate the versatile contributions of individual faculty members. Here, we propose a quantitative and objective faculty performance evaluation method. We established a well-structured quantitative evaluation system which scores faculty performance in key activities using expectation-based formula on key measures and then incorporates personalized flexible weights to integrate them into three area scores in teaching, research, and service as well as an overall score. It was implemented in a programed excel form, making it convenient to both faculty and evaluators and has generated very positive outcomes such as higher faculty satisfactory and improved productivity as indicated by associated increases in publications and new research grants etc. In conclusion, the quantitative faculty evaluation system provides more objective and transparent annual evaluation and a basis for making merit raise and award decisions. In addition, it can be readily adapted to evolving goals and needs of a department as well as different needs and cultures of different departments.
Anisotropic Multicomponent Topology Optimization for Additive Manufacturing With Build Orientation Design and Stress-Constrained Interfaces
Authors: Zhou Yuqing , Nomura Tsuyoshi , Saitou Kazuhiro 
Published: June 2020

Abstract
This paper presents a multicomponent topology optimization method for designing structures assembled from additively manufactured components, considering anisotropic material behavior for each component due to its build orientation, distinct material behavior, and stress constraints at component interfaces (i.e., joints). Based upon the multicomponent topology optimization (MTO) framework, the simultaneous optimization of structural topology, its partitioning, and the build orientations of each component is achieved, which maximizes an assembly-level structural stiffness performance subject to maximum stress constraints at component interfaces. The build orientations of each component are modeled by its orientation tensor that avoids numerical instability experienced by the conventional angular representation. A new joint model is introduced at component interfaces, which enables the identification of the interface location, the specification of a distinct material tensor, and imposing maximum stress constraints during optimization. Both 2D and 3D numerical examples are presented to illustrate the effect of the build orientation anisotropy and the component interface behavior on the resulting multicomponent assemblies.
Evaluating the Performance of a Modified Solar Air Heater With Pierced Cover and Packed Mesh Layers
Authors: Nowzari Raheleh , Saygin Hasan , Aldabbagh L.B.Y. 
Published: June 2020

Abstract
An experimental study was conducted to evaluate the thermal efficiency of a modified solar air heater. In the current design, air enters the collector through holes in front glass, passes through mesh layers, and exits at the backside of the air heater. A centrifugal fan was used to circulate air through the system. The design offers low construction costs and less solar radiation reflected from the collector. The modified collector was examined with various bed heights (30, 50, and 70 mm) and different mass flowrates of air varying from 0.011 kg/(s m2) to 0.043 kg/(s m2). The results showed that a counter flow collector with pierced cover had 5.6–9.7% higher efficiency than the single-pass one. The average efficiencies of the current design collector were found to be 55.2%, 44.6%, and 39.7% for the single-pass and 60.8%, 50.9% and 45.4% for the double-pass collector at 30, 50, and 70 mm bed heights and airflow rate of 0.043 kg/(s m2), respectively. The thermohydraulic efficiency, temperature difference, and perforated cover surface temperature were analyzed at each test and their effects on the system performance were evaluated. The highest amount of pressure drop through the collector was measured in the collector with a 70-mm bed height and a maximum air flowrate.
Semisupervised Physical Exercise and Lifestyle Counseling in Cardiometabolic Risk Management in Sedentary Adults: Controlled Randomized Trial (BELLUGAT)
Authors: Ensenyat Assumpta , Espigares-Tribo Gemma , Machado-Da-Silva Leonardo , Sinfreu-Bergués Xenia , Blanco Alfonso 
Published: June 2020

Background: The purpose of this study was to evaluate the feasibility and effectiveness of a high-intensity semisupervised exercise program alongside lifestyle counseling as an intervention for managing cardiometabolic risk in sedentary adults. Methods: A 40-week 3-arm randomized controlled clinical trial (16-wk intervention and 24-wk follow-up) was used. Seventy-five sedentary adults (34–55 y) with at least 1 cardiometabolic risk factor were randomized into one of the following arms: (1) aerobic interval training (AIT) plus lifestyle counseling (n = 25), (2) low- to moderate-intensity continuous training plus lifestyle counseling (traditional continuous training, TCT) (n = 27), or (3) lifestyle counseling alone (COU) (n = 23). Metabolic syndrome severity scores, accelerometer-based physical activity, and self-reported dietary habits were assessed at baseline, after the intervention, and at follow-up. Results: AIT was well accepted with high enjoyment scores. All groups showed similar improvements in metabolic syndrome severity scores (standardized effect size = 0.46) and dietary habits (standardized effect size = 0.30). Moderate to vigorous physical activity increased in all study groups, with the number of responders higher in AIT and TCT groups (50%) than in COU group (21%). Both AIT and TCT had a greater impact on sedentary behavior than COU (63.5% vs 30.4% responders). Conclusions: AIT appears to be a feasible and effective strategy in sedentary individuals with cardiometabolic risk factors. AIT could be included in intervention programs tackling unhealthy lifestyles.
Development and Validation of a Novel Knee-Specific Patient-Reported Outcomes Measure
Authors: Farnsworth James L. , Evans Todd , Binkley Helen , Kang Minsoo 
Published: June 2020

Context: Previous research suggests that several knee-specific patient-reported outcome measures have poor measurement properties. The patient-reported outcomes knee assessment tool (PROKAT) was created to improve assessment of knee-specific function. Examination of the measurement properties of this new measure is critical to determine its clinical value. Objective: Examine the measurement properties of the PROKAT. Design: Cross-sectional study. Setting: Clinical athletic training setting. Patients or Other Participants: The pilot study included 32 student-athletes (mean age = 20.78 [1.01], males = 56.30%). The full study included 203 student-athletes (mean age = 21.46 [4.64], males = 54.70%) from 3 separate institutions. The participants were recruited for both the pilot and full study using face-to-face and electronic (eg, email and social media sites) communications. Intervention(s): Evaluation of the measurement properties of the PROKAT occurred using the Rasch partial-credit model. Main Outcome Measures: Infit and outfit statistics, item step difficulties, person ability parameters, category function, item and test information functions, and Cronbach alpha. An independent samples t test was used to evaluate the differences in injured and noninjured athletes’ scores. Results: The Rasch partial-credit model analysis of pilot test items and qualitative participant feedback were used to modify the initial PROKAT. Evaluation of the revised PROKAT (32 items) indicated 27 items had acceptable model–data fit. The injured athletes scored significantly worse than the noninjured athletes (t188 = 12.89; P < .01). The ceiling effects for the PROKAT were minimal (3.9%). Conclusions: A major advantage of this study was the use of the Rasch measurement and the targeted population. Compared with alternative knee-specific patient-reported outcome measures (eg, Knee Injury Osteoarthritis Outcome Score, International Knee Documentation Committee Subjective Knee Form), the PROKAT has low ceiling effects in athletic populations. In addition, evidence suggests the measure may be capable of distinguishing between injured and noninjured athletes.
Validity and Reliability of Hand-Held Dynamometry for Abdominal Flexion Muscular Assessment
Authors: Tarca Brett D. , Wycherley Thomas P. , Meade Anthony , Bennett Paul , Ferrar Katia E. 
Published: June 2020

Context: Abdominal musculature underpins core stability, which can allow for optimal performance in many activities of daily living (eg, walking and rising from a chair). Therefore, assessment of the abdominal muscles poses as an important consideration for clinicians in order to identify people at risk of injury or functional decline. Objective: This study aimed to build on the limited amount of knowledge surrounding abdominal muscle strength assessments by investigating the validity and reliability of hand-held dynamometry (HHD) for the assessment of isometric abdominal flexion strength. Study Design and Participants: Comparative analysis for validity and test–retest reliability was employed on a cohort of apparently healthy individuals. HHD was compared with the criterion, isokinetic dynamometry, through an isometric contraction of trunk flexion on both instruments. Hand-held dynamometry assessments only were performed on a subsequent day for reliability analysis. The peak values for all assessments were recorded. Results: A total of 35 participants were recruited from the University of South Australia and the general public. Comparative analysis between the HHD and isokinetic dynamometer showed good agreement (intraclass correlation coefficients = .82), with the Bland–Altman plots confirming no proportional bias. Reliability analysis for the HHD reported good consistency (intraclass correlation coefficients = .87). Conclusion: HHD together with the participant setup (supine, trunk flexed, and supported at 25° with the legs horizontal and remaining unfixed) is a valid and reliable tool to assess isometric abdominal flexion strength.
Protocol for the development and validation of a measure of persistent psychological and emotional distress in cardiac patients: the Cardiac Distress Inventory
Authors: Jackson Alun , Rogerson Michelle , Le Grande Michael , Thompson David , Ski Chantal , Alvarenga Marlies , Amerena John , Higgins Rosemary , Raciti Michela , Murphy Barbara M 
Published: June 2020

IntroductionDistress is experienced by the majority of cardiac patients, yet no cardiac-specific measure of distress exists. The aim of this project is to develop and validate the Cardiac Distress Inventory (CDI). Using the CDI, health professionals will be able to identify key clusters of psychological, emotional and social concern to address with patients, postcardiac event.Methods and analysisAn item pool will be generated through: identification of items by a multidisciplinary group of clinician researchers; review of generic and condition-specific distress measures; focus group testing with cardiac rehabilitation professionals; feedback from patients. The COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) criteria will be used to inform the development of the methodology for determining the CDI’s psychometric properties. The item pool will be tested with 400 cardiac patients and responses subjected to exploratory factor analysis, Rasch analysis, construct validity testing and latent class analysis. Receiver operating characteristic analysis will be used to identify the optimal CDI cut-off score for distinguishing whether a person experiences clinically significant distress.Ethics and disseminationApproved by the Monash Health Human Research Ethics Committee (approval number—RES-19-0000631L-559790). The CDI will be made available to clinicians and researchers without charge. The CDI will be translated for use internationally. Study findings will be shared with cardiac patient support groups; academic and medical communities via publications and presentations; in the training of cardiac secondary prevention professionals; and in reports to funders. Authorship for publications will follow the uniform requirements for manuscripts submitted to biomedical journals.
Understanding current practice, identifying barriers and exploring priorities for adverse event analysis in randomised controlled trials: an online, cross-sectional survey of statisticians from academia and industry
Authors: Phillips Rachel , Cornelius Victoria 
Published: June 2020

ObjectivesTo gain a better understanding of current adverse event (AE) analysis practices and the reasons for the lack of use of sophisticated statistical methods for AE data analysis in randomised controlled trials (RCTs), with the aim of identifying priorities and solutions to improve practice.DesignA cross-sectional, online survey of statisticians working in clinical trials, followed up with a workshop of senior statisticians working across the UK.ParticipantsWe aimed to recruit into the survey a minimum of one statistician from each of the 51 UK Clinical Research Collaboration registered clinical trial units (CTUs) and industry statisticians from both pharmaceuticals and clinical research organisations.OutcomesTo gain a better understanding of current AE analysis practices, measure awareness of specialist methods for AE analysis and explore priorities, concerns and barriers when analysing AEs.ResultsThirty-eight (38/51; 75%) CTUs, 5 (5/7; 71%) industry and 21 attendees at the 2019 Promoting Statistical Insights Conference participated in the survey. Of the 64 participants that took part, 46 participants were classified as public sector participants and 18 as industry participants. Participants indicated that they predominantly (80%) rely on subjective comparisons when comparing AEs between treatment groups. Thirty-eight per cent were aware of specialist methods for AE analysis, but only 13% had undertaken such analyses. All participants believed guidance on appropriate AE analysis and 97% thought training specifically for AE analysis is needed. These were both endorsed as solutions by workshop participants.ConclusionsThis research supports our earlier work that identified suboptimal AE analysis practices in RCTs and confirms the underuse of more sophisticated AE analysis approaches. Improvements are needed, and further research in this area is required to identify appropriate statistical methods. This research provides a unanimous call for the development of guidance, as well as training on suitable methods for AE analysis to support change.