bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementation of Dahl’s dynamic friction model to contact mechanics of elastic solids
Authors: Balci Mehmet N. 
Published: January 2021

AbstractThis study presents an analytical method for the solution of dynamic frictional contact problem between a rigid punch and an isotropic elastic solid. Rigid flat punch moves over the isotropic elastic solid at a constant subsonic speed and friction force develops based on Dahl’s friction law instead of Coulomb’s dry friction law. Dahl’s dynamic friction model is adopted since this model is one of the well-known dynamic friction models in the literature. According to this model, friction force depends only on a displacement rather than the speed of the punch since viscous effects are ignored. Influences of the parameters describing Dahl’s friction model on contact stress at slow and high speed sliding cases are examined. Analytical solution is conducted by means of Galilean and Fourier transformations. Friction force is computed numerically by the use of 4th order Runge–Kutta method for various displacements of the punch. Formulation for the contact problem is reduced to a singular integral equation and normal stress over the surface of elastic half-plane is determined. Obtained contact stresses are compared with those generated through finite element method and results display a high degree of accuracy. The influences of direction of motion, Coulomb’s coefficient of friction, pre-sliding displacement, asperity stiffness and shape factor of hysteresis loop upon contact stresses and stress intensity factors are revealed.
Evaluation of furrow fertigation on nitrogen supply and losses as a function of maize growth stages
Authors: Mohseni Amir , Hosseini Hossein Mirseyed , Abbasi Fariborz 
Published: January 2021

AbstractThe purpose of this study was to evaluate the effects of furrow fertigation on nitrate deep leaching, nitrate runoff losses, and plant nitrogen supply in various growth stages of maize (Zea maysL.). Furrow fertigation experiment was conducted in 120 (W1), 100 (W2), 80 (W3), and 60% (W4) levels of required water (560 mm) and 100 (N1), 80 (N2), 60 (N3), and 0% (N4) levels of required nitrogen fertilizer (184 kg N ha−1). N-fertilizer was applied in four split applications (before planting, at the seven-leaf, shooting, and flowering). In the farmers’ conventional fertilization (FCF) method, 120% level of required water and 100% level of the required N-fertilizer were used in two split applications (before planting and at the seven-leaf stage). Results showed that the highest maize aboveground nitrogen content was 3.11% for FCF treatments at the seven-leaf stage. The maximum nitrogen content in the sensitive flowering stage and the maximum grain yield were also observed in W2N1 treatment with 2.27% and 12.93 ton ha−1, respectively. While, there were no significant differences in aboveground nitrogen content and grain yield between W2N1 and W3N1, W2N2, and W3N2. The highest amounts of nitrate leaching out of the 80-cm soil layer and nitrate runoff losses, were also recorded in FCF treatment, followed by W1N1, W2N1, and W3N1. Based on plant nitrogen content, nitrate losses and maize yield, 80% levels of the required N-fertilizer and required irrigation water could be recommended as the optimal levels to reduce nitrate losses and improve maize yield.
Co-pyrolysis of lignite and rapeseed cake: a comparative study on the thermal decomposition behavior and pyrolysis kinetics
Authors: Yaman Elif , Ulusal Aysu , Uzun Başak Burcu 
Published: January 2021

AbstractIn this study, physicochemical properties, co-pyrolysis kinetics and characteristics of lignite and rapeseed cake is investigated. While lignite has high calorific value, rapeseed cake has high volatile matter content and low moisture content that is suitable for the pyrolysis reactions. According to the thermal behavior of lignite and rapeseed cake blends, the addition of rapeseed cake into lignite provides to shift to lower initial decomposition temperature of blends compared to lignite. While rapeseed cake has a significant role in determining activation energies at the lower conversion degrees, lignite plays a vital role in specifying the activation energies at the higher conversion degrees. The char yield considerably decreases under the higher rapeseed cake ratio, while both of the bio-oil and gas yields increase. As conclusion, blending of rapeseed cake with lignite provides a positive synergy with regard to volatile yields and follows through different types of chemicals that can be valorized in various applications such as bio-chemicals and bio-fuel.
Wall reabsorption effects on heat and mass transfer of viscous fluid in a narrow leaky tube
Authors: Shahzad Aamir , Khan Waqar A. 
Published: January 2021

AbstractThe steady heat and mass transfer problem of flow of an incompressible Newtonian fluid is investigated in this study. The axisymmetric flow of a non-isothermal and highly viscous fluid is considered through a narrow leaky tube of uniform cross-section with linear reabsorption across the wall. The Navier–Stokes equations are solved for axially symmetric and slow flow in the tube. The effects of linear reabsorption parameter on the dimensionless radial and axial velocities, temperature, concentration, shear stress, leakage flux, fractional reabsorption, pressure drop across the tube as well as the Nusselt and Sherwood numbers have been investigated analytically. For 50% fractional reabsorption, inlet radial velocity is half of the reabsorption velocity along the tube. It has been shown that increase in the strength of linear reabsorption parameter considerably reduces the radial velocity, while, axial velocity shows opposite behaviour. At the exit region ($$z=0.9$$

z
=
0.9

), reverse flow phenomenon is observed for higher values of reabsorption parameter. The pressure, flow rate and wall shear stress decreases after entrance region ($$z=0.1$$

z
=
0.1

) of the tube. Nusselt number and Sherwood number show opposite behaviour inside the tube. At $$z=0.1$$

z
=
0.1

the magnitude of Nusselt number is maximum, while the Sherwood number is minimum at the exit region with higher value of reabsorption parameter.
Food forensics on gelatine source via ultra-high-performance liquid chromatography diode-array detector and principal component analysis
Authors: Ismail Azilawati Mohd , Sani Muhamad Shirwan Abdullah , Azid Azman , Zaki Nor Nadiha Mohd , Arshad Syariena , Tukiran Nur Azira , Abidin Siti Aimi Sarah Zainal , Samsudin Mohd Saiful , Ismail Amin 
Published: January 2021

AbstractThis study provided a step-by-step procedure to investigate the distribution of 17 amino acids (AAs) in 50 fish, 50 bovine and 54 porcine gelatines using Ultra-High-Performance Liquid Chromatography Diode-Array Detector (UHPLC–DAD) with the incorporation of principal component analysis (PCA). Dataset pre-processing step, including outlier removal, analysis of variance (ANOVA), dataset adequacy test, dataset transformation and correlation test was performed before the PCA. The method rendered linearity range of 37.5–1000 pmol/µL and accuracy of 85–111% recovery. The bovine and porcine gelatines showed a similar ranking while the l-Alanine (Ala), l-Arginine (Arg) and l-Glutamic acid (Glu) concentrations had differed the fish gelatine from the bovine and porcine gelatines. The PCA, which explained 77.013% cumulative variability at eigenvalue of 5.436, showed AAs with strong FL in PC1 had polar and nonpolar side chains while AAs with strong FL in PC2 had polar side chain. The AAs with moderate and weak FL in PC1 had a nonpolar side chain. The AAs with strong FL of in PC1 were also the same AAs with 7, 6 and 5 strong CMs as determined in the correlation test. The second PCA showed that the l-Serine (Ser), Arg, Glycine (Gly), l-Threonine (Thr), l-Methionine (Met), l-Histidine (His) and L-Hydroxyproline (Hyp) were significant in fish gelatine; Hyp, Met, Thr, Ser, His, Gly, and Arg in bovine gelatine; and l-Proline (Pro), l-Tyrosine (Tyr), l-Valine (Val), l-Leucine (Leu), and l-Phenylalanine (Phe) in porcine gelatine. The 100% fish, bovine and porcine gelatines accommodated grouping 1, 2 and 3, respectively, which proved that AAs with strong FL (Hyp, His, Ser, Arg, Gly, Thr, Pro, Tyr, Met, Val, Leu and Phe) were the significant AAs and becomes the biomarkers to identify the gelatine source. From this study, the PCA was a useful tool to analyse a multivariate dataset that could provide an in-depth understanding of AA distributions as compared to ANOVA and correlation test.
Study of critical failure surface influencing factors for loose rock slope
Authors: Wang Shuhong , Ahmed Zulkifl , Wang Pengyu 
Published: January 2021

AbstractIn current research, a novel geometrical technique is introduced to estimate the length (L) of sliding arc by considering slip surface entry point distance (de). Morgenstern-Price limiting equilibrium and strength reduction methods are selected within the framework of SLOPE/W and FLAC3D softwares respectively, to study the sliding mechanism and stability-effecting factor for a loose rock slope comprise of two different material. Also, the variability influence of strength parameters (cohesion force and friction angle) and the depth of pore water pressure on safety factor, failure depth (D) and distribution range of critical failure surface (CFS) are investigated through software. The results show that the shear strength parameters and the depth of pore water pressure plays a significant role in altering overall stability and the distribution range of CFS for a loose rock slope. Shallow failure with composite failure surface is much easier to occur for loose rock slope subjected to pore water pressure and material heterogeneity. These findings can be effectively used for loose rock slope reinforcement design.
Creating Immersive Virtual Environments Based on Open Geospatial Data and Game Engines
Authors: Keil Julian , Edler Dennis , Schmitt Thomas , Dickmann Frank 
Published: January 2021

AbstractModern game engines like Unity allow users to create realistic 3D environments containing terrains as well as natural and artificial objects easily and swiftly. In addition, recent advances of game engine capabilities enable effortless implementation of virtual reality (VR) compatibility. 3D environments created with VR compatibility can be experienced from an egocentric and stereoscopic perspective that surpasses the immersion of the ‘classical’ screen-based perception of 3D environments. Not only game developers benefit from the possibilities provided by game engines. The ability to use geospatial data to shape virtual 3D environments opens a multitude of possibilities for geographic applications, such as construction planning, spatial hazard simulations or representation of historical places. The multi-perspective, multimodal reconstruction of three-dimensional space based on game engine technology today supports the possibility of linking different approaches of geographic work more closely. Free geospatial data that can be used for spatial reconstructions is provided by numerous national and regional official institutions. However, the file format of these data sources is not standardized and game engines only support a limited number of file formats. Therefore, format transformation is usually required to apply geospatial data to virtual 3D environments. This paper presents several workflows to apply digital elevation data and 3D city model data from OpenStreetMap and the Open.NRW initiative to Unity-based 3D environments. Advantages and disadvantages of different sources of geospatial data are discussed. In addition, implementation of VR compatibility is described. Finally, benefits of immersive VR implementation and characteristics of current VR hardware are discussed in the context of specific geographic application scenarios.
Rapid shortening of survival duration in early fatal cases of COVID-19, Wuhan, China
Authors: Zhang Yuzhou , Bambrick Hilary , Tong Shilu , Lambert Stephen B , Hu Wenbiao 
Published: January 2021

Abstract
Severe COVID-19 cases place immediate pressure on hospital resources. To assess this, we analysed survival duration in the first 39 fatal cases in Wuhan, China. Time from onset and hospitalization to death declined rapidly, from ~40 to 7 days, and ~25 to 4 days, respectively, in the outbreak’s first month.
Subglottic suction frequency and adverse ventilator-associated events during critical illness
Authors: Abdallah Hatem O. , Weingart Melanie F. , Fuller Risa , Pegues David , Fitzpatrick Rebecca , Kelly Brendan J. 
Published: January 2021

AbstractObjective:Tracheal intubation and mechanical ventilation provide essential support for patients with respiratory failure, but the course of mechanical ventilation may be complicated by adverse ventilator-associated events (VAEs), which may or may not be associated with infection. We sought to understand how the frequency of subglottic suction, an indicator of the quantity of sputum produced by ventilated patients, relates to the onset of all VAEs and infection-associated VAEs.Design:We performed a case-crossover study including 87 patients with VAEs, and we evaluated 848 days in the pre-VAE period at risk for a VAE.Setting and participants:Critically ill patients were recruited from the medical intensive care unit of an academic medical center.Methods:We used the number of as-needed subglottic suctioning events performed per calendar day to quantify sputum production, and we compared the immediate pre-VAE period to the preceding period. We used CDC surveillance definitions for VAE and to categorize whether events were infection associated or not.Results:Sputum quantity measured by subglottic suction frequency is greater in the period immediately prior to VAE than in the preceding period. However, it does not discriminate well between infection-associated VAEs and VAEs without associated infection.Conclusions:Subglottic suction frequency may serve as a valuable marker of sputum quantity, and it is associated with risk of a VAE. However, our results require validation in a broader population of mechanically ventilated patients and intensive care settings.
LIFSCHITZ REALIZABILITY AS A TOPOLOGICAL CONSTRUCTION
Authors: RATHJEN MICHAEL , SWAN ANDREW W. 
Published: January 2021

AbstractWe develop a number of variants of Lifschitz realizability for $\mathbf {CZF}$ by building topological models internally in certain realizability models. We use this to show some interesting metamathematical results about constructive set theory with variants of the lesser limited principle of omniscience including consistency with unique Church’s thesis, consistency with some Brouwerian principles and variants of the numerical existence property.
GENERALISED WEIGHTED COMPOSITION OPERATORS ON BERGMAN SPACES INDUCED BY DOUBLING WEIGHTS
Authors: LIU BIN 
Published: January 2021

AbstractWe characterise bounded and compact generalised weighted composition operators acting from the weighted Bergman space$A^p_\omega $, where$0<p<\infty $and$\omega $belongs to the class$\mathcal {D}$of radial weights satisfying a two-sided doubling condition, to a Lebesgue space$L^q_\nu $. On the way, we establish a new embedding theorem on weighted Bergman spaces$A^p_\omega $which generalises the well-known characterisation of the boundedness of the differentiation operator$D^n(f)=f^{(n)}$from the classical weighted Bergman space$A^p_\alpha $to the Lebesgue space$L^q_\mu $, induced by a positive Borel measure$\mu $, to the setting of doubling weights.
The relationship between inflammatory dietary pattern and incidence of periodontitis
Authors: Alhassani Ahmed A. , Hu Frank B. , Rosner Bernard A. , Tabung Fred K. , Willett Walter C. , Joshipura Kaumudi J. 
Published: January 2021

AbstractThe long-term inflammatory impact of diet could potentially elevate the risk of periodontal disease through modification of systemic inflammation. The aim of the present study was to prospectively investigate the associations between a food-based, reduced rank regression (RRR)-derived, empirical dietary inflammatory pattern (EDIP) and incidence of periodontitis. The study population was composed of 34 940 men from the Health Professionals Follow-Up Study, who were free of periodontal disease and major illnesses at baseline (1986). Participants provided medical and dental history through mailed questionnaires every 2 years and dietary data through validated semi-quantitative FFQ every 4 years. We used Cox proportional hazard models to examine the associations between EDIP scores and validated self-reported incidence of periodontal disease over a 24-year follow-up period. No overall association between EDIP and the risk of periodontitis was observed; the hazard ratio comparing the highest EDIP quintile (most proinflammatory diet) with the lowest quintile was 0·99 (95 % CI 0·89, 1·10, P-value for trend = 0·97). A secondary analysis showed that among obese non-smokers (i.e. never and former smokers at baseline), the hazard ratio for periodontitis comparing the highest EDIP quintile with the lowest was 1·39 (95 % CI 0·98, 1·96, P-value for trend = 0·03). In conclusion, no overall association was detected between EDIP and incidence of self-reported periodontitis in the study population. From the subgroups evaluated, EDIP was significantly associated with increased risk of periodontitis only among non-smokers who were obese. Hence, this association must be interpreted with caution.
IDENTIFYING THE JUS COGENS NORM IN THE JUS AD BELLUM
Authors: Johnston Katie A 
Published: January 2021

AbstractThis article argues that if there is a jus cogens norm in the jus ad bellum, it must be the customary norm which prohibits non-consensual uses of force that are neither validly authorised under the UN Charter nor lawful exercises of self-defence. In doing so this article will clarify the method by which jus cogens norms should be identified, based on a correct understanding and application of what it means for a norm to be ‘accepted and recognized as a norm from which no derogation is permitted’. It is argued that all existing jus cogens norms must be norms of customary law, and that the uncertainty regarding the scope of the jus cogens norm prohibiting force results from uncertainty as to the structure of the underlying customary and treaty law norms in the jus ad bellum.
Design and Implementation of a Cable Inspection Robot for Cable-Stayed Bridges
Authors: Wang Zhipeng , He Bin , Zhou Yanmin , Liu Ke , Zhang Chenghong 
Published: January 2021

SUMMARY
Cable is the most important bearing structure of the cable-stayed bridges. Its safety has been of crucial public concern. Traditional manual cable inspection method has many defects such as low inspection efficiency, poor reliability and hazardous working environment. In this paper, a new wirelessly controlled cable-climbing robot enabling safe and convenient inspection of stay cables is proposed. The designed robot is composed of two modules, joined by four turnbuckles to form a closed structure that clasps the cable. The robot is controlled wirelessly by a ground-based station, and a DC power is supplied via an onboard lithium battery. The climbing principle and mechanical structure of this robot are introduced. The static model of the robot during obstacle negotiation is established. The relationships of the driving force and resistance with obstacle height to determine the obstacle-negotiation capability of the robot are obtained. The effects of cable diameter, cable inclination and preload force on obstacle climbing ability of the robot are also analyzed. The experiments verify that the robot could climb random inclined cables and overcome an obstacle of 2.42 mm in height with a mass of 5 kg payload.
The length of an s-increasing sequence of r-tuples
Authors: Gowers W. T. , Long J. 
Published: January 2021

AbstractWe prove a number of results related to a problem of Po-Shen Loh [9], which is equivalent to a problem in Ramsey theory. Let a = (a1, a2, a3) and b = (b1, b2, b3) be two triples of integers. Define a to be 2-less than b if ai < bi for at least two values of i, and define a sequence a1, …, am of triples to be 2-increasing if ar is 2-less than as whenever r < s. Loh asks how long a 2-increasing sequence can be if all the triples take values in {1, 2, …, n}, and gives a log* improvement over the trivial upper bound of n2 by using the triangle removal lemma. In the other direction, a simple construction gives a lower bound of n3/2. We look at this problem and a collection of generalizations, improving some of the known bounds, pointing out connections to other well-known problems in extremal combinatorics, and asking a number of further questions.
Growth and long-run sustainability
Authors: Cairns Robert D. , Martinet Vincent 
Published: January 2021

AbstractFrom any state of economic and environmental assets, the maximin value defines the highest level of utility that can be sustained forever. Along any development path, the maximin value evolves over time according to investment decisions. If the current level of utility is lower than this value, there is room for growth of both the utility level and the maximin value. For any resource allocation mechanism (ram) and economic dynamics, growth is limited by the long-run level of the maximin value, which is an endogenous dynamic sustainability constraint. If utility reaches this limit, sustainability imposes growth to stop, and the adoption of maximin decisions instead of the currentram. We illustrate this pattern in two canonical models, the simple fishery and a two-sector economy with a nonrenewable resource. We discuss what our results imply for the assessment of sustainability in the short and the long run in non-optimal economies.
Global Anglican Discourse and Women’s Ordination in Kenya: The Controversy in Kirinyaga, 1979–1992, and its Legacy
Authors: Kapinde Stephen Asol , Higgs Eleanor Tiplady 
Published: January 2021

AbstractIn the 1980s, the question of women’s ordination in the Anglican Church of Kenya (ACK) caused a controversy in Kirinyaga diocese, in which Archbishop David Gitari (1937–2013) played a critical role as an advocate for women. This controversy is just one example of how African Christian women have faced multiple material and theological obstacles to ordination, both in the Anglican Church and in other churches. Through an analysis of institutional texts we show how the issue of women’s ordination has been addressed in formal Anglican decision-making processes. We also outline the patriarchal attitudes that characterized the wider discourse of women’s ordination in Kenya and in the Anglican Communion, and discuss how this discourse informed Gitari’s intervention. Opposition to women’s ordination is only one facet of sexism in the ACK, as was implicitly recognized by Gitari in his wider project of ‘holistic development’.