bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the Case: Managing Carrying Capacity at Arches National Park
Authors: Ward-Perkins David 
Published: February 2021

Introduction
The question of carrying capacity is one faced by many protected natural areas. It might appear simple: if the number of visitors is such that it risks damaging the environment or biodiversity, then that number should be restricted or the visitor flow modified. On closer examination, the issues raised are complex. How do you define ‘damage’? How do you establish that a number is too high? Is it too high only at certain moments or in certain places? Can visitor behaviour be influenced? If one imposes restrictions, should all visitors be treated alike, or should some have priority?
The more we consider carrying capacity, the more we realize that it is connected to many other issues. The case of Arches gives us an insight, therefore, on how a National Park Authority approaches visitor management as a whole.
Elastic electron collisions with trimethyl phosphate
Authors: Bardela F P , da Silva A J , da Mata V A S , Homem M G P , Iga I , Sugohara R T , Fujimoto M M 
Published: February 2021

Abstract
An experimental investigation of elastic electron scattering by trimethyl phosphate (C3H9PO4) is presented. Differential cross sections were measured in the 5–800 eV and 10°–130° and from these data momentum-transfer cross sections were derived. Calculations of the scattering cross sections in the intermediate energy range were performed within the independent atom model framework at static-exchange-polarization plus absorption level of approximation. The comparison between our measured and calculated results presents, in general, a good agreement.
Impact of angular irradiance distributions on coupling gains and energy yield of cell interconnection designs in silicon solar modules in tracking and fixed systems
Authors: Haedrich Ingrid , Ernst Marco 
Published: February 2021

Abstract
Cell interconnector designs such as light redirecting films (LRFs) and various geometric ribbon layouts are all aimed at improving the performance of crystalline silicon solar modules. However, due to the usually specular reflecting surface, the angular-dependent module performance, which is typically quantified with an incidence angle modifier, depends on the rotation of the module. We find that typical power measurements under standard test conditions at 1000 W m−2 and 25 °C cell temperature are not suited to identify the best performing design in real-world conditions. In this work, we therefore determine the optimum ribbon geometry based on its simulated energy yield in common installation configurations for solar modules based on industry-standard full and half-cut solar cells. We compare the effects of planar, triangular, LRFs, pentagonal and wire ribbon geometries, as well as fixed optimal inclination, building-integrated (façade), and single-axis tracking installation scenarios of modules in portrait and landscape orientation. Energy yield gains of 1.8% can be achieved for full cell modules with LRFs or pentagonal ribbons in single-axis tracking installation compared to a reference module with five planar ribbons. Critically, we find that changing the module orientation to landscape reduces this energy yield gain by nearly 50% for the modules with LRFs. This directional dependence is significantly reduced with the pentagonal ribbon structure. The installation scenario can have a similarly dramatic impact. The expectation of power gains for certain designs inferred from standard test conditions may not only show significantly lower gains in annual energy yield, but may even lead to yield losses, especially for building-integrated photovoltaic systems. For a typical full-cell module, for example, we have found that LRFs perform 2.5% better than standard planar ribbons under standard test conditions but can result in a 0.2% lower annual yield in a façade installation. Therefore, to fully evaluate the effectiveness of a specific ribbon design, the annual energy yield must consider the angular irradiance distribution and weather conditions at a specific location, the installation scenario, and the module orientation.
SiC siligraphene: a novel SiC allotrope with wide tunable direct band gap and strong anisotropy
Authors: Long Hui , Hu Jianwei , Xie Xing , Hu Peiju , Wang Shaoxiong , Wen Minru , Zhang Xin , Wu Fugen , Dong Huafeng 
Published: February 2021

Abstract
By employing an ab initio evolutionary algorithm, we predict two novel metastable structures whose energies are just higher than g-SiC but lower than other two-dimensional (2D) SiC siligraphenes reported so far. One is composed of 4-6-8 C–Si rings named tho-SiC siligraphene and the other one is composed of 5-6-8 rings named pho-SiC siligraphene. They are almost equal in energy, but interestingly, our calculations demonstrate that tho-SiC siligraphene is a semiconductor like g-SiC, while pho-SiC siligraphene is a 2D metal. Additionally, unlike g-SiC which is very easy to switch from a direct band gap to indirect band gap semiconductor and exhibits homogenous isotropy characteristic under biaxial strains, tho-SiC siligraphene keeps a consistently direct band gap from 1.02 eV to 1.98 eV as the uniaxial strain increases from −9% to 9% and it shows strong anisotropic electronic structures. The obtained calculation results indicate that tho-SiC siligraphene may be a better candidate than g-SiC in the application of light-emitting devices in the future.
Encoded injection of microbubbles to improve flow velocity measurements using cross-correlation technique
Authors: Desmond Kenneth W , Hunter Gary L 
Published: February 2021

Abstract
We present techniques to measure fluid flow rates in single- and multi-phase fluid flows by detecting the motion of injected tracers. Our methods exploit acoustic impedance differences between liquids and gases to allow one to sense the presence of micron-sized gas bubbles in a liquid when it is irradiated with ultrasonic energy. By cross-correlating signals at multiple locations along the path of flow, the velocity of the moving fluid can be accurately estimated. We report experimental results in single- and two-phase fluid flows and describe the methodologies used in each case that are necessary to enable accurate measurements. In cases of single- and two- phase flows, respectively, flow rates can be measured to less than 5% and less than 10%–15% of known flow rates. While our experiments leveraged differences in acoustic properties, the methods may be generalized to other means of measurement.
Large magnetic anisotropy in an OsIr dimer anchored in defective graphene
Authors: Navrátil Jan , Błoński Piotr , Otyepka Michal 
Published: February 2021

Abstract
Single-atom magnets represent the ultimate limit of magnetic data storage. The identification of substrates that anchor atom-sized magnets firmly and, thus, prevent their diffusion and large magnetic anisotropy has been at the centre of intense research efforts for a long time. Using density functional theory we show the binding of transition metal (TM) atoms in defect sites in the graphene lattice: single vacancy and double vacancy, both pristine and decorated by pyridinic nitrogen atoms, are energetically more favourable than away from the centre of defects, which could be used for engineering the position of TMs with atomic precision. Relativistic calculations revealed magnetic anisotropy energy (MAE) of ∼10 meV for Ir@NSV with an easy axis parallel to the graphene plane. MAE can be remarkably boosted to 50 meV for OsIr@NSV with the easy axis perpendicular to the graphene plane, which paves the way to the storage density of ∼490 Tb/inch2 with the blocking temperature of 14 K assuming the relaxation time of 10 years. Magnetic anisotropy is discussed based on the relativistic electronic structures. The influence of an orbital-dependent on-site Coulomb repulsion U and a non-local correlation functional optB86b-vdW on MAE is also discussed.
Calibrated uncertainty estimation for interpretable proton computed tomography image correction using Bayesian deep learning
Authors: Nomura Yusuke , Tanaka Sodai , Wang Jeff , Shirato Hiroki , Shimizu Shinichi , Xing Lei 
Published: February 2021

Abstract
Integrated-type proton computed tomography (pCT) measures proton stopping power ratio (SPR) images for proton therapy treatment planning, but its image quality is degraded due to noise and scatter. Although several correction methods have been proposed, techniques that include estimation of uncertainty are limited. This study proposes a novel uncertainty-aware pCT image correction method using a Bayesian convolutional neural network (BCNN). A DenseNet-based BCNN was constructed to predict both a corrected SPR image and its uncertainty from a noisy SPR image. A total 432 noisy SPR images of 6 non-anthropomorphic and 3 head phantoms were collected with Monte Carlo simulations, while true noise-free images were calculated with known geometric and chemical components. Heteroscedastic loss and deep ensemble techniques were performed to estimate aleatoric and epistemic uncertainties by training 25 unique BCNN models. 200-epoch end-to-end training was performed for each model independently. Feasibility of the predicted uncertainty was demonstrated after applying two post-hoc calibrations and calculating spot-specific path length uncertainty distribution. For evaluation, accuracy of head SPR images and water-equivalent thickness (WET) corrected by the trained BCNN models was compared with a conventional method and non-Bayesian CNN model. BCNN-corrected SPR images represent noise-free images with high accuracy. Mean absolute error in test data was improved from 0.263 for uncorrected images to 0.0538 for BCNN-corrected images. Moreover, the calibrated uncertainty represents accurate confidence levels, and the BCNN-corrected calibrated WET was more accurate than non-Bayesian CNN with high statistical significance. Computation time for calculating one image and its uncertainties with 25 BCNN models is 0.7 s with a consumer grade GPU. Our model is able to predict accurate pCT images as well as two types of uncertainty. These uncertainties will be useful to identify potential cause of SPR errors and develop a spot-specific range margin criterion, toward elaboration of uncertainty-guided proton therapy.
Synthesizing optical spectra using computer-generated holography techniques
Authors: Holland Connor M , Lu Yukai , Cheuk Lawrence W 
Published: February 2021

Abstract
Experimental control and detection of atoms and molecules often rely on optical transitions between different electronic states. In many cases, substructure such as hyperfine or spin-rotation structure leads to the need for multiple optical frequencies spaced by MHz to GHz. The task of creating multiple optical frequencies—optical spectral engineering—becomes challenging when the number of frequencies becomes large, a situation that one could encounter in complex molecules and atoms in large magnetic fields. In this work, we point out a novel mapping between computer-generated holography (CGH) and spectrum generation via phase modulation, which is an established technique. Using this mapping, we synthesize arbitrary optical spectra by modulating a monochromatic light field with a time-dependent phase generated through CGH techniques. Our method is compatible with non-linear optical processes such as sum frequency generation and second harmonic generation. Additional requirements that arise from the finite lifetimes of excited states can also be satisfied in our approach. As a proof-of-principle demonstration, we generate spectra suitable for cycling photons on the X–B transition in CaF, and verify via optical Bloch equation simulations that one can achieve high photon scattering rates, which are important for fluorescent detection and laser cooling. Our method could offer significant simplifications in future experiments that would otherwise be prohibitively complex.
Non-similar mixed convection analysis for magnetic flow of second-grade nanofluid over a vertically stretching sheet
Authors: Raees Ammarah , Farooq Umer , Hussain Muzamil , Khan Waseem Asghar , Farooq Fozia Bashir 
Published: February 2021

Abstract
The aspiration of this research is to explore the impact of non-similar modeling for mixed convection in magnetized second-grade nanofluid flow. The flow is initiated by the stretching of a sheet at an exponential rate in the upward vertical direction. The buoyancy effects in terms of temperature and concentration differences are inserted in the

x

-momentum equation. The aspects of heat and mass transfer are studied using dimensionless thermophoresis, Schmidt and Brownian motion parameters. The governing coupled partial differential system (PDEs) is remodeled into coupled non-similar nonlinear PDEs by introducing non-similar transformations. The numerical analysis for the dimensionless non-similar partial differential system is performed using a local non-similarity method via bvp4c. Finally, the quantitative effects of emerging dimensionless quantities on the non-dimensional velocity, temperature and mass concentration in the boundary layer are conferred graphically, and inferences are drawn that important quantities of interest are substantially affected by these parameters. It is concluded that non-similar modeling, in contrast to similar models, is more general and more accurate in convection studies in the presence of buoyancy effects for second-grade non-Newtonian fluids.
CO2emissions from karst cascade hydropower reservoirs: mechanisms and reservoir effect
Authors: Wang Wanfa , Li Si-Liang , Zhong Jun , Wang Lichun , Yang Hong , Xiao Huayun , Liu Cong-Qiang 
Published: February 2021

AbstractCarbon dioxide (CO2) emissions from aquatic surface to the atmosphere has been recognized as a significant factor contributing to the global carbon budget and environmental change. The influence of river damming on the CO2emissions from reservoirs remains poorly constrained. This is hypothetically due to the change of hydraulic retention time (HRT) and thermal stratification intensity of reservoirs (related to the normal water level, NWL). To test this hypothesis, we quantified CO2fluxes and related parameters in eight karst reservoirs on the Wujiang River, Southwest China. Our results showed that there was a significant difference in the values ofpCO2(mean = 3205.7μatm, SD = 2183.4μatm) andδ13CCO2(mean = −18.9‰, SD = 1.6‰) in the cascade reservoirs, suggesting that multiple processes regulate CO2production. Moreover, the calculated CO2fluxes showed obvious spatiotemporal variations, ranging from −9.0 to 2269.3 mmol m−2d−1, with an average of 260.1 mmol m−2d−1. Interestingly, the CO2flux andδ13CCO2from reservoirs of this study and other reservoirs around the world had an exponential function with the reservoir effect index (Ri, HRT/NWL), suggesting the viability of our hypothesis on reservoir CO2emission. This empirical function will help to estimate CO2emissions from global reservoirs and provide theoretical support for reservoir regulation to mitigate carbon emission.
Second-order Markov chain models of rainfall in Ibadan, Southwest Nigeria
Authors: Ogunjo S. T. , Fuwape I. A. , Oluyamo S. S. , Rabiu A. B. 
Published: February 2021

Abstract
Understanding the dynamics of rainfall is important for maximizing the agricultural potential, environmental planning, as well as policy development. In this study, a two-state second-order Markov chain model was developed for the annual and daily occurrence of different rainfall sequences in Ibadan, southwestern Nigeria. The annual variation was adapted to a sine series model. The model was able to account for more than 30% of the observed variation. Markov chain approach to modelling rainfall in tropical region is unique because it considers the “memory” – previous rainfall events, which is lacking in other methods. The daily occurrences showed patterns consistent with tropical regions. Results from this study is significant for economic, health and environmental planning in the location.
Trends in extreme temperature indices over Lagos, Nigeria
Authors: Ogunjo S. T. , Akinsusi J. O. , Fuwape I. A. 
Published: February 2021

Abstract
There is the need to understand the trend and impact of extreme temperature on coastal cities because they are generally susceptible to extreme precipitation events. This study explores the trend in extreme temperature for Lagos State, Nigeria. The indices for daily minimum and maximum temperature data was calculated for the period 1991–2015 using the RClimDex software. The result showed that both minimum value of daily minimum temperature (TNn) and cool days (TX10p) showed negative trends among the indices considered. Significant trends were observed in warm nights (TN90p), warm days (TX90p) and mean of maximum temperature (Tmax-mean). Warm nights were found to be increasing while cold nights are either unchanged or decreasing. This study reveals that there are evidences of increase in warming of Lagos State.
Towards Improving Artisan and Craftsmen Productivity
Authors: Amusan L.M. , Oluwatobi O. , Dalshe C. , Ezenduka J. , Emetere M. , Owolabi J.D. , Tunji-Olayeni P.F. 
Published: February 2021

Abstract
The construction industry plays a noteworthy part in contribution to the gross domestic product of developing countries. Nigeria being a developing country, the construction industry is highly labour intensive labour intensive. For the purpose of this study, the data collection instrument used was structured questionnaire making use of the 5-point Likert scale. Sample size of 52 was chosen from population frame of 60 construction firms was adopted for the study. The study found out among other things that there should be periodic increase in wages of artisans and craftsmen, schedule should be mad flexible, provision of incentives and motivation, strategies such as periodic assessment of artisans skill should be implemented, stakeholders to have a say in artisan training and organizing training programs by construction firms. To this end the need for highly performing craftsmen construction industry is not debatable, Craftsmen are the major employee of the construction industry, since most of the work in the construction industry has to be done manually by hand, therefore they deserve to be well equipped and given the best of the training on account of their contributions.
Determination of volume of wastewater generated in a university campus
Authors: Omole D.O. , Chichezie T.E. , Akpan V.E. 
Published: February 2021

Abstract
The development of wastewater reuse schemes has been greatly slowed down by the lack of adequate wastewater generation data. Most data sources on wastewater generation provided by international organizations are mere estimates ofa nation’swastewater generation pattern and can only go a long way in explaining the wastewater situation of that nation. Intensive wastewater reuse schemes for futuristic purposes would require collection and storage of wastewater data for effective planning. This study identifies and closes that gap in a University campus where there is a high demand of water for daily use. Flowrates of wastewater being discharged into the environment was determined over a period of time using a standard weir and a level measuring tool. From this, the volume of wastewater generated was calculated. The results show that about 1,529,288 liters of wastewater was generated daily in the University campus. From this value, the water consumption rate of the university community was estimated to be 1,911,610 liters of water daily. From these findings, the wastewater generated within the Covenant University campus could be sufficient for agricultural, urban and other municipal reuse schemes. The environmental, economic and public health benefits from wastewater recycling are enormous and thus more attention must be given to its generation, treatment, disposal and reuse.
Enhancing catalytic epoxide ring-opening selectivity using surface-modified Ti3C2T
x
MXenes
Authors: Slot Thierry K , Natu Varun , Ramos-Fernandez Enrique V , Sepúlveda-Escribano Antonio , Barsoum Michel , Rothenberg Gadi , Shiju N Raveendran 
Published: February 2021

Abstract
MXenes are a new family of two-dimensional carbides and/or nitrides. Their 2D surfaces are typically terminated by O, OH and/or F atoms. Here we show that Ti3C2T
x
—the most studied compound of the MXene family—is a good acid catalyst, thanks to the surface acid functionalities. We demonstrate this by applying Ti3C2T
x
in the epoxide ring-opening reaction of styrene oxide (SO) and its isomerization in the liquid phase. Modifying the MXene surface changes the catalytic activity and selectivity. By oxidizing the surface, we succeeded in controlling the type and number of acid sites and thereby improving the yield of the mono-alkylated product to >80%. Characterisation studies show that a thin oxide layer, which forms directly on the Ti3C2T
x
surface, is essential for catalysing the SO ring-opening. We hypothesize that two kinds of acid sites are responsible for this catalysis: In the MXene, strong acid sites (both Lewis and Brønsted) catalyse both the ring-opening and the isomerization reactions, while in the Mxene–TiO2 composite weaker acid sites catalyse only the ring-opening reaction, increasing the selectivity to the mono-alkylated product.
Intersections and unions of a general family of function spaces
Authors: Bao Guanlong , Wulan Hasi , Ye Fangqin 
Published: February 2021

In this paper, we investigate the strict inclusion relation associated with intersections and unions of a general family of function spaces. We answer partially a question left open in Korhonen and Rättyä [Comput. Methods Funct. Theory 5 (2005), pp. 459–469].
Wild dynamics and asymptotically separated sets
Authors: Tapia-García Sebastián 
Published: February 2021

Let

X
X

be a separable infinite dimensional (real or complex) Banach space. Hájek and Smith, in 2010, constructed a linear bounded operator

T
T

on

X
X

such that

A
T

≔
{
x
∈
X
:

‖

T
n

x
‖
→
∞
}

A_T≔\{x\in X:~ \|T^nx\|\to \infty \}

is not dense and has nonempty interior, whenever

X
X

admits a symmetric basis. Augé, in 2012, extended the previous construction to each separable Banach space, introducing the notion of wild operators. This work is divided in two parts. In the first part we define and explore the notion of asymptotically separated sets on Banach spaces, giving several examples whenever the ambient space has either finite or infinite dimension. We show how these sets can be used to construct operators with non-intuitive dynamics. Specifically, operators

T
:
X
→
X

T:X\rightarrow X

for which the set

A
T

A_T

and the set of recurrent points form a partition of the space. Secondly, we investigate geometric and spectral properties of operators with wild dynamic and we provide a wild operator whose spectrum is equal to the closed unit disk. We end this paper giving some comments about the norm closure of the set of wild operators.