bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic obstructive pulmonary disease exacerbation fundamentals: Diagnosis, treatment, prevention and disease impact
Authors: MacLeod Mairi , Papi Alberto , Contoli Marco , Beghé Bianca , Celli Bartolome R. , Wedzicha Jadwiga A. , Fabbri Leonardo M. 
Published: April 2021

AbstractIn chronic obstructive pulmonary disease (COPD), exacerbations (ECOPD), characterized by an acute deterioration in respiratory symptoms, are fundamental events impacting negatively upon disease progression, comorbidities, wellbeing and mortality. ECOPD also represent the largest component of the socioeconomic burden of COPD. ECOPDs are currently defined as acute worsening of respiratory symptoms that require additional therapy. Definitions that require worsening of dyspnoea and sputum volume/purulence assume that acute infections, especially respiratory viral infections, and/or exposure to pollutants are the main cause of ECOPD. But other factors may contribute to ECOPD, such as the exacerbation of other respiratory diseases and non‐respiratory diseases (e.g., heart failure, thromboembolism). The complexity of worsening dyspnoea has suggested a need to improve the definition of ECOPD using objective measurements such as blood counts and C‐reactive protein to improve accuracy of diagnosis and a personalized approach to management. There are three time points when we can intervene to improve outcomes: acutely, to attenuate the length and severity of an established exacerbation; in the aftermath, to prevent early recurrence and readmission, which are common, and in the long‐term, establishing preventative measures that reduce the risk of future events. Acute management includes interventions such as corticosteroids or antibiotics and measures to support the respiratory system, including non‐invasive ventilation (NIV). Current therapies are broad and better understanding of clinical phenotypes and biomarkers may help to establish a more tailored approach, for example in relation to antibiotic prescription. Other unmet needs include effective treatment for viruses, which commonly cause exacerbations. Preventing early recurrence and readmission to hospital is important and the benefits of interventions such as antibiotics or anti‐inflammatories in this period are not established. Domiciliary NIV in those patients who are persistently hypercapnic following discharge and pulmonary rehabilitation can have a positive impact. For long‐term prevention, inhaled therapy is key. Dual bronchodilators reduce exacerbation frequency but in patients with continuing exacerbations, triple therapy should be considered, especially if blood eosinophils are elevated. Other options include phosphodiesterase inhibitors and macrolide antibiotics. ECOPD are a key component of the assessment of COPD severity and future outcomes (quality of life, hospitalisations, health care resource utilization, mortality) and are a central component in pharmacological management decisions. Targeted therapies directed towards specific pathways of inflammation are being explored in exacerbation prevention, and this is a promising avenue for future research.
Acupuncture as a tool to reduce nausea in terminally ill patients
Authors: Brøndum Lotte , Markfoged Birte , Finderup Jeanette 
Published: April 2021

AbstractAimTo investigate if acupuncture reduces nausea and vomiting in terminally ill patients.DesignA comparative effectiveness research design was used to generate evidence‐based knowledge close to practice for the use of clinicians. The sample size was calculated to 136 patients randomised into an intervention and a control group, respectively. Nausea and vomiting were measured using the EORTC QLQ‐c15‐PAL (European Organisation for Research and Treatment of Cancer, Quality of Life Questionnaire, core 15, Palliation).LocationThe trial was conducted among terminally ill patients admitted to three in‐bed hospices in Demark.ParticipantsTerminally ill patients suffering from nausea and/or vomiting; 95% of patients had cancer.InterventionThe intervention group received acupuncture in addition to usual care for three days. We used the acupuncture spots: Pericardium‐6, Stomach‐36, Liver‐3 and Yin Tang. The control group received usual care only.ResultsIn total, 136 patients were randomised, 24 patients withdrew resulting in a total sample of 112 patients: 52 patients in the intervention group and 60 patients in the control group. In the intervention group, 75% of the patients experienced a reduction of their nausea score after the intervention compared to 55% in the control group. The statistical difference was p = 0.028. In the intervention group, 52% of the patients did not experience nausea at all after the intervention compared to 30% in the control group. In the intervention group, 31% of the patients were still vomiting after the intervention compared to 34% in the control group; no statistically significant difference was found.ConclusionAcupuncture reduced the experience of nausea among terminally ill patients but did not reduce vomiting. Thus, acupuncture is recommended to reduce nausea among terminally ill patients.
Detecting initial aragonite and calcite variations in limestone–marl alternations
Authors: Nohl Theresa , Steinbauer Manuel J. , Sinnesael Matthias , Jarochowska Emilia 
Published: April 2021

AbstractLimestone–marl alternations are commonly used for high‐resolution cyclostratigraphic studies and palaeoenvironmental reconstructions, but diagenetic studies indicate that not all limestone–marl alternations reflect genuine differences in the initial sediment composition driven by environmental changes. Differences in the ratios of diagenetically inert trace elements between limestones and marls indicate changes affecting the terrigenous fraction of the precursor sediment. Contrarily, limestone–marl alternations without these differences can be the product of: (i) variations in CaCO3 input (aragonite, calcite); (ii) distortion of the latter by diagenetic CaCO3 redistribution; or (iii) diagenetic CaCO3 redistribution in a homogeneous precursor sediment. The aim of this study is to provide a method to differentiate these cases and to identify variations in the proportion of calcite and aragonite in the precursor sediment composition. The model of differential diagenesis assumes that the concentration of diagenetically inert elements is inversely proportional to the amount of redistributed CaCO3. Consequently, the difference between ratios of diagenetically inert elements from two adjacent beds is a measure for CaCO3 redistribution. This is quantifiable by the vector length between ratios from two adjacent beds. The approach is illustrated here by evaluation of a case study from the Silurian of Gotland, Sweden. Trace elements were compared according to their solubility during diagenesis. All elements bound to clay minerals or calcite show similar patterns of vector length, while vector length of elements which fit into the aragonite lattice, and are diagenetically mobile, differ. The vector length approach provides a tool to test the diagenetic origin of limestone–marl alternations, to identify initial variations in CaCO3 input and to test a limestone–marl alternation’s suitability for cyclostratigraphic analyses.
Multi-Objective Surrogate-Assisted Stochastic Optimization for Engine Calibration
Authors: Pal Anuj , Wang Yan , Zhu Ling , Zhu Guoming G. 
Published: April 2021

Abstract
A surrogate-assisted optimization approach is an attractive way to reduce the total computational budget for obtaining optimal solutions. This makes it special for its application to practical optimization problems requiring a large number of expensive evaluations. Unfortunately, all practical applications are affected by measurement noises, and not much work has been done to address the issue of handling stochastic problems with multiple objectives and constraints. This work tries to bridge the gap by demonstrating three different frameworks for performing surrogate-assisted optimization on multi-objective constrained problems with stochastic measurements. To make the algorithms applicable to real-world problems, heteroscedastic (nonuniform) noise is considered for all frameworks. The proposed algorithms are first validated on several multi-objective numerical problems (unconstrained and constrained) to verify their effectiveness and then applied to the diesel engine calibration problem, which is expensive to perform and has measurement noises. A gt-suite model is used to perform the engine calibration study. Three control parameters, namely, variable geometry turbocharger (VGT) vane position, exhaust-gas-recirculating (EGR) valve position, and the start of injection (SOI), are calibrated to obtain the tradeoff between engine fuel efficiency performance (brake specific fuel consumption (BSFC)) and NOx emissions within the constrained design space. The results show that all three proposed extensions can handle the problems well with different measurement noise levels at a reduced evaluation budget. For the engine calibration problem, a good approximation of the optimal region is observed with more than 80% reduction in the evaluation budget for all the proposed methodologies.
Optimized Economic Operation of Microgrid: Combined Cooling and Heating Power and Hybrid Energy Storage Systems
Authors: Abdalla Ahmad N. , Nazir Muhammad Shahzad , Tiezhu Zhu , Bajaj Mohit , Sanjeevikumar P. , Yao Liu 
Published: April 2021

Abstract
With the rapid development of clean energy, the combined cooling and heating power (CCHP) and hybrid energy storage system (HESS) have become matured significantly. However, further optimizing the configuration of the energy supply system and adjusting the output of distributed micro-sources and energy storage units are still attractive issues. This paper focuses on the two-stage optimization strategy of the microgrid system, including CCHP and HESS. The details of the operating characteristics and mathematical models of distributed micro-sources in the system are presented. The energy storage architecture is used for mathematical modeling, and the optimization model is analyzed from the two perspectives of energy supply and demand, which explores the feasibility of improving the economic operation of the micro-energy system. The two-stage optimization model in which the first stage is to determine the optimal installation capacity of various equipment and the second stage determines the optimal operation plan of the system by obtaining the system’s capacity configuration. The simulation results show that the CCHP system can reduce the operation cost by 4.61% and 6.48% for winter and summer, respectively, also reduce fuel cost consumption by 3.01% and 3.68% for winter and summer, respectively.
Design Equations for Mixed-Mode Fracture of Dental Ceramic–Cement Interfaces Using the Brazil-Nut-Sandwich Test
Authors: Manan David Tamim , Kim Jeongho , de Melo Renata Marques , Zhang Yu 
Published: April 2021

AbstractDental interfaces are subject to mixed-mode loading. This study provides practical guidance for determining interfacial fracture toughness of dental ceramic systems. We address interfacial fracture of a composite resin cement sandwiched between two dental ceramic materials. Emphasis is placed on sandwich disc specimens with cracks originating from elliptical-shaped flaws near the center, for which analytical fracture mechanics methods fail to predict. The interaction integral method is used to provide accurate finite element solutions for cracks with elliptical-shaped flaws in a Brazil-nut-sandwich specimen. The developed model was first validated with existing experimental data and then used to evaluate the three most widely used dental ceramic systems: polycrystalline ceramics (zirconia), glass-ceramics (lithium disilicate), and feldspathic ceramics (porcelain). Contrary to disc specimens with ideal cracks, those with cracks emanating from elliptical-shaped flaws do not exhibit a monotonic increase in interfacial toughness. Also, interfacial fracture toughness is seen to have a direct relationship with the aspect ratio of elliptical-shaped flaws and an inverse relationship with the modulus ratio of the constituents. The presence of an elliptical-shaped flaw significantly changes the interfacial fracture behavior of sandwich structures. Semi-empirical design equations are provided for fracture toughness and stress intensity factors for interfacial cracks. The developed design equations provide practical guidance for determining interfacial fracture toughness of selected dental ceramic material systems. Those equations take into account four critical factors: size of the elliptical flaw, modulus ratio of constituent materials, loading angle, and applied load.
X-Ray Characterization of Real Fuel Sprays for Gasoline Direct Injection
Authors: Sforzo Brandon A. , Tekawade Aniket , Kastengren Alan L. , Fezzaa Kamel , Ilavsky Jan , Powell Christopher F. , Pei Yuanjiang , Zhang Anqi , Levy Robert 
Published: April 2021

Abstract
The effects of fuel blend properties on spray and injector performance has been investigated in a side-mount injector for gasoline direct injection (GDI) using two certification fuel blends: Euro 5 and Euro 6. Several X-ray diagnostic techniques were conducted to characterize the injector and spray morphology. Detailed internal geometry of the GDI injector was resolved to 1.8 μm, through the use of hard X-ray tomography. The geometry characterization of this six-hole GDI, side mount injector, quantifies relevant hole and counterbore dimensions and reveals the intricate details within the flow passages, including surface roughness and micron-sized features. Internal valve motion was measured with a temporal resolution of 20 μs and a spatial resolution of 2.0 μs, for three injection pressures and several injector energizing strategies. The needle motion for both fuels exhibits similar lift profiles for common energizing commands. A combination of X-ray radiography and ultra-small-angle X-ray scattering (USAXS) was used to characterize the fuel mass distribution and the droplet sizing, respectively. Tomographic spray radiography revealed the near-nozzle distribution of fuel mass for each of the fuels and the asymmetry produced by the angled nozzles. Under evaporative conditions, the two fuels show minor differences in peak fuel mass distribution during steady injection, though both exhibit fluctuations in injection during the early, transient phase. USAXS measurements of the path-specific surface area of the spray indicated lower peak values for the more evaporative conditions in the near nozzle region.
Numerical Modeling of the Wave Soldering Process and Experimental Validation
Authors: Carvalho Violeta , Arcipreste Bruno , Soares Delfim , Ribas Luís , Rodrigues Nelson , Teixeira Senhorinha F. C. F. , Teixeira José Carlos 
Published: April 2021

Abstract
One of the most important procedures in the electronics industry is the assembly of electronic components onto printed circuit boards (PCBs) through the soldering process. Among the various soldering methods available, wave soldering is a very effective technique. In this process, the components are placed onto the PCB, which, subsequently, is coated with a flux and then passed across a preheat zone. In the end, the assembly is moved by the conveyor and passed over the surface of the molten solder wave in order to create a reliable connection both mechanically and electrically. Although this process has been frequently used, there are soldering defects that remain unsolved and continue to emerge, such as the missing of surface-mount components in the PCB after the soldering process. Aiming to understand if such defects are related to the force exerted by the solder wave in the PCB, a numerical and experimental study was performed in this article. For this purpose, a computational fluid dynamic model was developed by using the fluent software to describe the interaction between the solder jet and the PCB with the integrated circuits, and the multiphase method, volume of fluid, was also applied to track the solder–air interface boundary. The results obtained were numerically validated by using an experimental setup designed and built to this end. In general, the data obtained showed to be in good agreement and it was concluded that the force exerted by the solder wave is approximately 0.02 N.
Analytical Determination of the Optimal Clearance for the Fatigue Life of Ball Bearing Under Different Load Conditions
Authors: Fang Bin , Zhang Jinhua 
Published: April 2021

Abstract
In this paper, a comprehensive analytical model for the fatigue life prediction of ball bearing in various operating conditions is presented. Not only the internal clearance variations induced by the centrifugal expansion and assembly interference but also ball inertia forces and ball–raceway separations are fully considered in theoretical modeling to achieve accurate life prediction of the ball bearing. The model has been validated by comparison with the static results in previous literature. Based on this, the results of the load distribution and fatigue life versus the internal clearance of ball bearing under various operating conditions are studied. The results show that there is always an optimal clearance to maximize bearing fatigue life for the radial load or the combined load conditions, and the size of the optimal clearance for bearing life is determined by both the load conditions and rotating speeds to ensure the uniformity of the internal load distribution of the ball bearing. Therefore, the above-mentioned theoretical and conclusions can be used in structural design optimization and assembly parameters selection of ball bearing to maximize the life characteristic.
The Effects of Gravity on the Response of Centrifugal Pendulum Vibration Absorbers
Authors: Tchokogoué Darryl , Mu Ming , Feeny Brian F. , Geist Bruce K. , Shaw Steven W. 
Published: April 2021

Abstract
This article describes the effects of gravity on the response of systems of identical, cyclically arranged, centrifugal pendulum vibration absorbers (CPVAs) fitted to a rotor spinning about a vertical axis. CPVAs are passive devices composed of movable masses suspended on a rotor, suspended such that they reduce torsional vibrations at a given engine order. Gravitational effects acting on the absorbers can be important for systems spinning at relatively low rotation speeds, for example, during engine idle conditions. The main goal of this study is to predict the response of a CPVA/rotor system in the presence of gravity. A linearized model that includes the effects of gravity and an order n torque acting on the rotor is analyzed by exploiting the cyclic symmetry of the system. The results show that a system of N absorbers responds in one or more groups, where the absorbers in each group have identical waveforms but shifted phases. The nature of the waveforms can have a limiting effect on the absorber operating envelope. The number of groups is shown to depend on the engine order n and the ratio N/n. It is also shown that there are special resonant effects if the engine order is n = 1 or n = 2, the latter of which is particularly important in applications. In these cases, the response of the absorbers has a complicated dependence on the relative levels of the applied torque and gravity. In addition, it is shown that for N &gt; 1, the rotor response is not affected by gravity, at least to leading order, due to the cyclic symmetry of the gravity effects. The linear model and the attendant analytical predictions are verified by numerical simulations of the full nonlinear equations of motion.
Effects of 8-Week FIFA 11+ for Kids Intervention on Physical Fitness and Attention in Elementary School Children
Authors: Tseng Wen-Yen , Rekik Ghazi , Chen Chia-Hui , Clemente Filipe M. , Bezerra Pedro , Crowley-McHattan Zachary J. , Chen Yung-Sheng 
Published: April 2021

Background: The psychological and physiological adaptations in response to the FIFA 11+ for kids (FIFA11+kid) program has not been examined in school children. This study aimed to investigate the effects of 8-week FIFA11+kid intervention on physical fitness and attentional capacity in elementary school children. Methods: A total of 55 elementary school students voluntarily participated in the study. Participants were assigned to either the FIFA11+kid (n = 28, 5 times per week) or the control (n = 27) group. At baseline and after 8 weeks, all participants were asked to perform a battery of physical fitness tests (sit-and-reach, broad jump, sit-up test, and 800-m run) and the Attention Scale for Elementary School Children, including 5 subscales: focused, sustained, selective, alternating, and divided attentions. Results: The FIFA11+kid group demonstrated larger pre–post change in sit-and-reach (P < .001) and sit-up test (P < .001) than that of control group. Moreover, the FIFA11+kid group demonstrated large improvements pre–post change in Attention Scale for Elementary School Children scores of total score (P < .001), focused (P < .001), sustained (P < .001), and selective attentions (P < .001) compared with the control group. Conclusion: A total of 8 weeks of FIFA11+kid exercise intervention can improve general physical fitness and attentional capacities in elementary school children.
Trait Perfectionism and Dance Goals Among Young Female Dancers: An Application of the 2 × 2 Model of Perfectionism
Authors: Molnar Danielle S. , Blackburn Melissa , Zinga Dawn , Spadafora Natalie , Methot-Jones Tabitha , Connolly Maureen 
Published: April 2021

This study provided the first test of the 2 × 2 model of perfectionism with respect to dancers’ goals for dancing in competitive dance. Four hundred twenty-five young female North American competitive dancers (M = 11.33 years;SD = 2.14) completed questionnaires assessing multidimensional perfectionism and goals for participation in dance. The latent moderated structural equations approach along with procedures outlined by Gaudreau indicated partial support for the 2 × 2 model of perfectionism. Pure Evaluative Concerns Perfectionism was associated with fewer intrinsic goals for dance and greater extrinsic goals for dance relative to nonperfectionism. Pure Personal Standards Perfectionism was related to less endorsement of extrinsic goals relative to nonperfectionism. Findings were complex with respect to mixed perfectionism, with this form of perfectionism being related to greater endorsement of both intrinsic and extrinsic goals for dance. Results provide partial support for the 2 × 2 model in youth dance.