bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Peak Energy Demand for an Office Building Using Artificial Intelligence (AI) Approaches
Authors: Chen Yuxuan , Phelan Patrick 
Published: August 2021

Abstract
Due to the technological advancement in smart buildings and the smart grid, there is increasing desire of managing energy demand in buildings to achieve energy efficiency. In this context, building energy prediction has become an essential approach for measuring building energy performance, assessing energy system efficiency, and developing energy management strategies. In this study, two artificial intelligence techniques (i.e., ANN = artificial neural networks and SVR = support vector regression) are examined and used to predict the peak energy demand to estimate the energy usage for an office building on a university campus based on meteorological and historical energy data. Two-year energy and meteorological data are used, with one year for training and the following year for testing. To investigate the seasonal load trend and the prediction capabilities of the two approaches, two experiments are conducted relying on different scales of training data. In total, 10 prediction models are built, with 8 models implemented on seasonal training datasets and 2 models employed using year-round training data. It is observed that a backpropagation neural network (BPNN) performs better than SVR when dealing with more data, leading to stable generalization and low prediction error. When dealing with less data, it is found that there is no dominance of one approach over another.
Analysis of a Multigeneration Energy System for Wastewater Treatment
Authors: Erguvan Mustafa , MacPhee David W. 
Published: August 2021

Abstract
The United Nations World Water Development Report claims that more than 6 billion people will suffer from clean water shortage by 2050. This is a result of climate change, demand increase for water, increase of water pollution, increasing population, and reduction of water resources [1]. In order to delay / prevent water scarcity, humans must take action using less water or perhaps recovering wastewater. Aerobic digestion is one of the best common methods to treat wastewater; however, this technology requires heavily on the use of electric motors and is estimated to consume 2–3% of US electricity. In this paper, a multigeneration energy system is developed to treat wastewater using a net-zero energy building model. This system consists of four major sub-systems: an aerobic digester, an anaerobic digester, a Brayton cycle, and a Rankine cycle. Using anaerobic digestion to produce bio-fuels, which can then be used on-site to power aeration systems, may offer significant advantages to reduce electricity usage. This study shows that the required energy for a sample aeration case study process can be supplied by a multigeneration system. Parametric analyses are performed to show how system efficiency may be increased as well as to investigate the required oxygen and power for an activated sludge process in a wastewater treatment plant. It is found here that the proposed CHP system can produce 6 times more energy than the required energy for the aeration in the activated sludge process.
First Numerical Evaluation of the Thermal Performance of a Tubular Receiver Equipped With Raschig Rings for CSP Applications
Authors: Ebadi Hossein , Allio Andrea , Cammi Antonio , Savoldi Laura 
Published: August 2021

Abstract
Porous media are typically capable to enhance heat transfer, at the cost of an increase of the pressure drop, mainly in view of the huge increase in the surface wetted by the fluid. In this work, a tubular receiver for CSP applications, partly filled with a porous medium constituted by a packed bed of copper Raschig Rings is investigated for the first time. The analysis, carried out numerically, aims at studying in detail the mechanisms of the heat transfer from the wall to the gaseous heat transfer fluid (air) through the porous metal matrix in symmetric and asymmetric heating conditions. The computed results are compared to what occurs in a smooth tube subjected to the same heating, to check the increase in the heat transfer. The investigation carried out in this work represents the first step in the optimization of the porous medium structure inside the tubular receiver.
Adjoint Optimization of Heat Transfer Within a Stirling Engine
Authors: DiCarlo Anthony A. , Caldwell Rickey A. 
Published: August 2021

Abstract
This work aims to determine the optimal heat sink fin shape to promote the efficient rise of hot air away from the heat sink. The heat transfer and convective flow dynamics external to a commercial Stirling engine are investigated. In particular, this study employs an adjoint optimization approach based on CFD simulations to determine the sensitivity of the objective function to the shape of the heat sink and influence on the natural convection heat flow away from the external heat sink. This deterministic optimization approach increases the heat transfer rate of the heat sink by nearly 20% in this study when performing a small number of design iterations.
Generalized Reynolds Analogy: An Engineering Prospective of Thermo-Fluid Physics for Heat Exchanger Design
Authors: Som Abhijit 
Published: August 2021

Abstract
In practical interest of Reynolds analogy for power and process industries, in a unified system approach an engineering prospective of thermo-fluid physics has been proposed by developing a theory of basic heat exchanger design and analysis. Needless to mention of excellent books on heat exchangers, this paper focuses on the novelty of heat exchanger, which in author’s view depends upon the possibility of energy exchange between two fluid streams at different temperatures. Since operation cannot be random, the principal act of design is to engineer a product such that it operates in specified manner to perform its desired function of de-energizing one stream by virtue of energizing the other.
With law of the integral as the guiding principle of physics, it shall be made clear that energy exchange in the form of heat must be accompanied by energy transfer such that heat exchanger must operate due to simultaneous process of cooling and heating of the fluid streams with an intervening medium. To unlock the secret of steady operation a fundamental postulate concerning thermodynamic behavior of the system has been made by invoking zeroth law of thermodynamics. Remarkably, it lends itself a necessary and sufficient condition concerning proportionality between heat-flux and required temperature difference to yield fluids unique thermal response in relation to the heat transfer surface temperature. Consequently, far-reaching physical implications of the constant of proportionality on system design can be clearly exposed of with due consideration to Eulerian descriptions of conservation principles according to Newton’s mechanical theory. Consistently enough, because of thermal non-equilibrium, effectiveness of system design and off design performance warrants a fundamental theorem like one suggested by Reynolds concerning augmentation of thermal diffusion due to fluid motion. Accordingly, flow rates become critical operating parameters for thermal performance and pressure drop requirements.
Furthermore, and most importantly, in support of the theorem an order magnitude analysis appears to be in order, to show the dependence of flow resistance and hence, system thermal response on fluid flow behavior in terms of non-dimensional parameters. As a result, it is made clear that development of design correlations for friction factor and non-dimensional heat transfer coefficient in terms of both Reynolds number and Prandtl number is an integral part of heat exchanger design process by gathering experimental data. Finally, generalized mathematical statement of Reynolds analogy has been obtained relating Stanton number with friction factor, which reduces to our familiar expression for Prandtl number of unity.
Design Considerations of Solar-Driven Hydrogen Production Plants for Residential Applications
Authors: Berastain Arturo , Vidal Rafael , Busquets Carlos , Aguilar Gonzalo , Torres Álvaro , Lem Jorge , Antoniou Antonios , Celis Cesar 
Published: August 2021

Abstract
The objective of this work is to discuss design considerations related to the development of a stand-alone photovoltaic driven hydrogen production and consumption system. The referred system is currently on the design-phase so this work describes in particular the associated design considerations, governing equations, schematics and the expected system efficiency. The system design requirements include the production of enough energy to power an average residence located in the Ica city, Peru. The system design has been divided in four subsystems, each one having its own design considerations and limitations, (i) power, hydrogen (ii) production, (iii) storage and (iv) consumption. Regarding the power subsystem, the required considerations to generate the maximum amount of solar energy in the minimum amount of space are presented. For hydrogen production, different electrolyzer related technologies have been accounted for; including proton exchange (PEM), alkaline (AEC) and polymer (PEC). Hydrogen and oxygen storages are a critical aspect in the full hydrogen chain production. Currently no single technology satisfies all of the criteria required. As such, present technologies and selection considerations are presented. For using the produced hydrogen, fuel cell stacks including PEM and solid oxide ones are assessed. Finally, the right the combination of current, voltage (including conversion from DC to a constant AC supply) and fuel utilization maximizing efficiency and power output is determined.
Automatic Electronic Braking System for Commercial Micro Wind Turbine
Authors: Hiraldo-Martínez Gretchell M. , Santiago-Vargas Alex D. , Aponte-Roa Diego A. , Goenaga-Jiménez Miguel A. 
Published: August 2021

Abstract
The inclusion of renewable energy as wind turbines on microgrids has been increasing in popularity. However, commercial micro wind turbines lack advance electronic control systems to monitor the turbine and automatically brake for safety purposes. This paper presents the design of a modular electronic braking and monitoring system architecture with off-the-shelf electronic components and open-source software. The proposed system records the turbine operational parameters and triggers a braking system when an emergency stop button is closed or when a desired electrical parameter exceeds an established threshold. Electronic braking is a low-cost alternative that needs less maintenance, space, and mechanical complexity. We used a 400W micro wind turbine located at 17 feet high to test the proposed system architecture. Results demonstrate that this system architecture could be implemented for wind turbines in any existing polygeneration microgrid as an add-on.
Association of Physical Activity With Maximal and Submaximal Tests of Exercise Capacity in Middle- and Older-Aged Adults
Authors: Mediano Mauro F.F. , Fleg Jerome L. , Wanigatunga Amal A. , Gonçalves Tatiana R. , Martinez-Amezcua Pablo , Szklo Moyses , Simonsick Eleanor M. , Ferrucci Luigi , Schrack Jennifer A. 
Published: August 2021

Although physical activity (PA) is an important determinant of exercise capacity, the association between these constructs is modest. The authors investigated the associations of self-reported and objectively measured PA with maximal and submaximal tests of exercise capacity. Participants aged ≥40 years (N = 413; 49.6% female) completed a PA questionnaire, wore a uniaxial accelerometer (5.2 ± 1.1 days), and performed maximal (cardiopulmonary exercise test [CPET]) and submaximal (long-distance corridor walk) tests with indirect calorimetry (oxygen consumption, ). Linear regression models were fitted to assess the variation in exercise capacity explained (partial eta squared, η2) by PA variables. Accelerometer-measured vigorous (η2 = 22% female; η2 = 16% male) and total PA (η2 = 17% female; η2 = 13% male) explained the most variance in CPET (p < .001). All η2 values were lower for long-distance corridor walk (η2 ≤ 11%). Age contributed more to CPET than any PA variable in males (η2 = 32%), but not in females (η2 = 19%). Vigorous and total PA play important roles in CPET in mid to late life.
Field and petrographic reconnaissance of Franciscan complex rocks of Mount Diablo, California: Imbricated ocean floor stratigraphy with a roof exhumation fault system
Authors: Wakabayashi John 
Published: August 2021

ABSTRACT
Franciscan subduction complex rocks of Mount Diablo form a 8.5 by 4.5 km tectonic window, elongated E-W and fault-bounded to the north and south by rocks of the Coast Range ophiolite and Great Valley Group, respectively, which lack the burial metamorphism and deformation displayed by the Franciscan complex. Most of the Franciscan complex consists of a stack of lawsonite-albite–facies pillow basalt overlain successively by chert and clastic sedimentary rocks, repeated by faults at hundreds of meters to &lt;1 m spacing. Widely distributed mélange zones from 0.5 to 300 m thick containing high-grade (including amphibolite and eclogite) assemblages and other exotic blocks, up to 120 m size, form a small fraction of exposures. Nearly all clastic rocks have a foliation, parallel to faults that repeat the various lithologies, whereas chert and basalt lack foliation. Lawsonite grew parallel to foliation and as later grains across foliation. The Franciscan-bounding faults, collectively called the Coast Range fault, strike ENE to WNW and dip northward at low to moderate average angles and collectively form a south-vergent overturned anticline. Splays of the Coast Range fault also cut into the Franciscan strata and Coast Range ophiolite and locally form the Coast Range ophiolite–Great Valley Group boundary. Dip discordance between the Coast Range fault and overlying Great Valley Group strata indicates that the northern and southern Coast Range fault segments were normal faults with opposite dip directions, forming a structural dome. These relationships suggest accretion and fault stacking of the Franciscan complex, followed by exhumation along the Coast Range fault and then folding of the Coast Range fault.
Miocene stratigraphy and structure of the East Bay Hills, California
Authors: Wagner J. Ross , Deino Alan , Edwards Stephen W. , Sarna-Wojcicki Andrei M. , Wan Elmira 
Published: August 2021

ABSTRACT
The structure and stratigraphy of the Miocene formations east of San Francisco Bay have been described in multiple studies for over a century. We integrated the results of past investigations and provide new data that improve understanding of formation age, the timing of deformation, and the amount of dextral displacement on selected faults. New geologic mapping and better age control show that formations previously inferred to be separate units of different ages are correlative, and new names are proposed for these units. Miocene structures associated with the development of the San Andreas transform system exerted significant control on Miocene deposition in the East Bay area. The developing structure created five distinct stratigraphic sections that are differentiated on the basis of differences in the stratigraphic sequence, lithology, and age. The stratigraphic changes are attributed to significant dextral displacement, syndepositional faulting, and distal interfingering of sediment from tectonically elevated source areas. New stratigraphic evaluations and age control show that prior to ca. 6 Ma, the developing fault system created local tectonically induced uplift as well as spatially restricted subbasins. Regional folding did not occur until after 6 Ma. Past evaluations have inferred significant dextral displacement on some of the faults in the East Bay. The spatial relationships between unique conglomerate clasts and known source areas, as well as the distribution of well-dated and unique tuffs, suggest that dextral displacement on some faults in the East Bay is less than previously reported.
Impact of the Step-by-Step on febrile infants
Authors: Gomez Borja , Fernandez-Uria Amaia , Benito Javier , Lejarzegi Ainara , Mintegi Santiago 
Published: August 2021

ObjectiveTo evaluate the impact of introducing the Step-by-Step approach on care quality in young febrile infants.DesignObservational study including infants ≤90 days old with fever without source seen in a paediatric emergency department 5 years before (n=1222) and after (n=1151) its introduction. Quality of care was evaluated in terms of adherence to recommendations, resource use and safety.ResultsAdherence: percentages of infants undergoing both urine and blood tests and infants <15 days old receiving full sepsis evaluation increased (84.7% vs 91.0% and 23.9% vs 63.3%, respectively; p<0.01). Resource use: lumbar puncture and admission rates decreased (24.1% vs 18.7% and 43.6% vs 38.3%, respectively; p<0.01), while the rate of antibiotic therapy increased (30.2% vs 43.2%; p<0.01). Safety: the invasive bacterial infection rate among infants managed as outpatients was unchanged (0.7% vs 0.3%; p=0.24).ConclusionThe introduction of the Step-by-Step increased the quality of care provided to young febrile infants.
Joint associations of depression, genetic susceptibility and the area of residence for coronary heart disease incidence
Authors: Silventoinen Karri , Korhonen Kaarina , Lahtinen Hannu , Jelenkovic Aline , Havulinna Aki S , Ripatti Samuli , Salomaa Veikko , Davey Smith George , Martikainen Pekka 
Published: August 2021

BackgroundDepression is a risk factor for coronary heart disease (CHD), but less is known whether genetic susceptibility to CHD or regional-level social indicators modify this association.MethodsRisk factors of CHD including a Polygenic Risk Score (PRS) were measured for 19 999 individuals residing in Finland in 1997, 2002, 2007 and 2012 (response rates 60%–75%). During the register-based follow-up until 2015, there were 1381 fatal and non-fatal incident CHD events. Unemployment rate, degree of urbanisation and crime rate of the municipality of residence were used as regional level social indicators. HRs were calculated using register-based antidepressant purchases as a non-reversible time-dependent covariate.ResultsThose having depression and in the highest quartile of PRS had somewhat higher CHD risk than predicted only by the main effects of depression and PRS (HR for interaction 1.53, 95% CI 0.95 to 2.45). Depression was moderately associated with CHD in high crime (HR 1.51, 95% CI 1.20 to 1.90) and weakly in low crime regions (HR 1.07, 95% CI 0.86 to 1.33; p value of interaction=0.087). Otherwise, we did not found evidence for interactions.ConclusionsThose having both depression and high genetic susceptibility need a special attention in healthcare for CHD.
Bioenergy yield of Eucalyptus urophylla clones and its relationship with the mean annual increment of wood volume
Authors: da Silva Bruna Isabele Pinheiro , Santos Alyne Chaveiro , da Silva Macksuel Fernandes , de Moraes Mariana Dianese Alves , Sette Carlos Roberto 
Published: August 2021

This study aimed to evaluate the energy yield and wood characteristics of Eucalyptus urophylla S.T.Blake clones with different mean annual increment (MAI) of wood volume. The clones presented MAIs of 39.2, 54.1, and 70.0 m3·ha−1·year−1 in the field experiment at 6 years after planting when the trees were cut down to evaluate the wood basic density and higher heating values. The energy density, dry mass, and energy yield were estimated. The MAI of E. urophylla clones influenced the wood basic density, dry mass, and energy yield, but did not influence the higher heating value and energy density. Clone 3 had the highest MAI as well as higher energy yield and dry mass, but lower wood basic density. The difference between the most and the least productive clones was 242 648 MJ·ha−1·year−1. The results reinforce the importance of evaluating the wood quantity production (MAI) when selecting E. urophylla clones for energy purposes.
Gluon propagators in $$2+1$$ lattice QCD with nonzero isospin chemical potential
Authors: Bornyakov V. G. , Nikolaev A. A. , Rogalyov R. N. , Terentev A. S. 
Published: August 2021

AbstractThe static longitudinal and transverse gluon propagators in the Landau gauge are studied in $$2+1$$

2
+
1

lattice QCD with nonzero isospin chemical potential $$\mu _I$$

μ
I

. Parameterization of the momentum dependence of the propagators is provided for all values of the chemical potential under study. We find that the longitudinal propagator is infrared suppressed at nonzero $$\mu _I$$

μ
I

with suppression increasing with increasing $$\mu _I$$

μ
I

. It is found, respectively, that the electric screening mass is increasing with increasing $$\mu _I$$

μ
I

. Additionally, we analyze the difference between two propagators as a function of the momentum and thus compare interactions in chromoelectric and chromomagnetic sectors.
Synchronizability analysis of three kinds of dynamical weighted fractal networks
Authors: Li Jian-Hui , Liu Jin-Long , Yu Zu-Guo , Li Bao-Gen , Huang Da-Wen 
Published: August 2021

In this paper, we study the synchronizability of three kinds of dynamical weighted fractal networks (WFNs). These WFNs are weighted Cantor-dust networks, weighted Sierpinski networks and weighted Koch networks. We calculated some features of these WFNs, including average distance ([Formula: see text]), fractal dimension ([Formula: see text]), information dimension ([Formula: see text]), correlation dimension ([Formula: see text]). We analyze two representative types of synchronizable dynamical networks (the type-I and the type-II). There are two indexes ([Formula: see text] and [Formula: see text]) that can be used to characterize the synchronizability of the two types of dynamical network. Here, [Formula: see text] and [Formula: see text] are the minimum nonzero eigenvalue and the maximum eigenvalue of the Laplacian matrix of the network, respectively. We find that the larger scaling factor [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] or [Formula: see text] implies stronger synchronizability for the type-I dynamical WFNs.
Long-term landform evolution
Authors: Migoń Piotr 
Published: August 2021

Abstract
This chapter reviews major advances in studies of long-term landform evolution in the last few decades of the twentieth century. These include in particular the development of the etchplanation concept, which evolved into a dynamic approach linking inheritance, environmental change and contemporary processes, realization of the importance of weathering mantles in deciphering landscape evolution over long timescales, recognition of varying ancient landforms, especially in the Southern Hemisphere, and insights into preglacial landscapes at high latitudes that survived successive glaciations.