bluuebunny/crossref_metadata_2025_split huggingface dataset:
Practitioner observations of oral nicotine use in elite sport: You snus you lose
Authors: Kasper Andreas M. , Close Graeme L. 
Published: December 2020

AbstractThe elite sport environment is one where athletes strive to find a competitive edge, through improved recovery modalities, cognitive performance or physical capacity. Due to this, non‐scientifically evidenced and/or pseudo‐scientific alternative remedies are ever popular. Snus (an oral tobacco based product containing the highly addictive compound nicotine) is one alternative ‘physical and psychological performance enhancer’, purported to act as a ‘mental and physical booster’, ‘relaxative’ and even as an ‘appetite suppressor’. Despite snus having serious adverse health effects, along with no proven benefit to physical or mental performance, observations by the authors working in professional sport, along with several reports in the mainstream media, would suggest that the use of snus in elite sport appears to be increasing. Perhaps most worrying, the use of snus has been reported to be prevalent within younger athletes. It is crucial that athletes are fully educated with regards to the health implications of snus and other oral tobacco‐based products, whilst practitioners should be aware of its growing prevalence in sport with strategies in place to discourage its use.
More of the bulk from extremal area variations
Authors: Bao Ning , Cao ChunJun , Fischetti Sebastian , Pollack Jason , Zhong Yibo 
Published: December 2020

Abstract
It was shown recently in (Bao N et al 2019 Class. Quantum Grav.
36 185002), building on work of Alexakis, Balehowksy, and Nachman (Alexakis S et al 2017 arXiv:1711.09379), that the geometry of (some portion of) a manifold with boundary is uniquely fixed by the areas of a foliation of two-dimensional disk-shaped surfaces anchored to the boundary. In the context of AdS/CFT, this implies that (a portion of) a four-dimensional bulk geometry can be fixed uniquely from the entanglement entropies of disk-shaped boundary regions, subject to several constraints. In this note, we loosen some of these constraints, in particular allowing for the bulk foliation of extremal surfaces to be local and removing the constraint of disk topology; these generalizations ensure uniqueness of more of the deep bulk geometry by allowing for e.g. surfaces anchored on disconnected asymptotic boundaries, or HRT surfaces past a phase transition. We also explore in more depth the generality of the local foliation requirement, showing that even in a highly dynamical geometry like AdS-Vaidya it is satisfied.
The effect of Cu additions in FePt–BN–SiO2 heat-assisted magnetic recording media
Authors: Streubel Robert , N’Diaye Alpha T , Srinivasan Kumar , Kalitsov Alan , Jain Shikha , Ajan Antony , Fischer Peter 
Published: December 2020

Abstract
Structural and chemical order impact magnetic properties of solids, which are governed by spin–orbit coupling and exchange interaction. The ordered L10 phase of FePt is a key material to heat-assisted magnetic recording; to enable high storage density, a solid understanding is needed of structural and chemical disorder at small length scales, as well as associated modifications of the electronic band structure. Here, we investigate the effect of boron and copper additions (≲6 mol% Cu) on structural and magnetic properties of L10 FePt granular media. Two copper-driven mechanisms, although competing, can lead to improvements in both structural and magnetic properties. In particular, the Cu substitution on the Fe-site leads to a degradation of magnetic properties due to the delocalized electron orbitals originating from a larger Cu d-orbital occupancy. At the same time, Cu substitution leads to an enhanced crystallographic order and consequently magneto-crystalline anisotropy, which offsets the former effect to a large extent. Our study is based on magnetometry, x-ray absorption spectroscopy, ab-initio calculations and a phenomenological theory of disordered FePt granular media. We do not observe a sizable modification to Fe moments and electronic configuration; Cu reveals two different resonances associated with the presence and absence of Cu–B bonds that vary with total Cu concentration.
Quantum numbers of the pentaquark states

Pc+

via symmetry analysis
Authors: Chen Chong-yao , Chen Muyang , Liu Yu-Xin 
Published: December 2020

Abstract
We investigate the quantum numbers of the pentaquark states

P

c

+

, which are composed of 4 (three flavors) quarks and an antiquark, by analyzing their inherent nodal structure in this paper. Assuming that the four quarks form a tetrahedron or a square, and the antiquark is at the ground state, we determine the nodeless structure of the states with orbital angular moment L ≤ 3, and in turn, the accessible low-lying states. Since the inherent nodal structure depends only on the inherent geometric symmetry, we propose the quantum numbers J

P
of the low-lying pentaquark states

P

c

+

may be

3

2

−

,

5

2

−

,

3

2

+

and

5

2

+

, independent of dynamical models.
Phase tracking with Hilbert transform and nonlinear wave-wave coupling analysis on the HL-2A tokamak
Authors: Zang L.G. , Ohshima S. , Qu Y.F. , Shi P.W. , Zhong W.L. , Hou Y.M. , Yan L.W. , Ji X.Q. , Li J.Q. , Yu D.L. , Shi Z.B. , Liu Yi , Yang Q.W. , Xu M. 
Published: December 2020

Abstract
A phase tracking method based on Hilbert transform algorithm is applied to the nonlinear wave-wave coupling analysis on HL-2A tokamak. Synthetic signal analysis is given to show the principle of phase analysis for the detection of nonlinear coupling. If the phase difference between two coherent modes is synchronized with the phase of a third mode, these three modes are nonlinearly coupled, vice versa. The time evolution of the phase of a coherent mode could be computed with Hilbert transform for experimental data, and a phase tracking flowchart is summarized. On HL-2A tokamak, the nonlinear coupling among two Alfvén modes (AMs) and a tearing mode (TM) has been confirmed with bicoherence analysis (Shi et al 2017 Phys. Plasmas
24 042509). With Hilbert transform, it is clearly observed that the phase difference between two AMs Δθ
12 is synchronized with the phase of the TM θ
TM. The synchronization is confirmed with normalized cross-correlation. An alternative to check this synchronization is to observe the histogram of the phase difference Δθ
12 − θ
TM.
Thinking styles and engineering: proposals for strengthening the professional training of engineers through physics courses
Authors: Gaete-Peralta C , Huincahue J 
Published: December 2020

AbstractOne way to contribute to the strengthening of professional training processes in Engineering is through teaching and evaluation methods physics courses that promote those thinking styles that should be preferred by an engineer to solve tasks of their profession. Based on the above, the objective of this research was to identify those thinking styles that ideally a graduate of industrial civil engineering from a certain Chilean university should prefer to perform their profession tasks. Responding to this objective, it will be possible to generate educational proposals in physics courses for that career. For this, a qualitative methodology called thematic analysis was used. The data sources were semi-structured interviews with academics with enough experience in the career, besides the analysis of the institutional graduation profile. From a deductive perspective, according to the thinking styles, the ideal preferences for the egislative, judicial, global, hierarchical, liberal and external styles emerged as a result. Finally, a discussion was held on some teaching and evaluation methods that can be carried out in the physics courses of this career in order to promote these thinking styles.
Phenomenology and scaling of optimal flapping wing kinematics
Authors: Gehrke Alexander , Mulleners Karen 
Published: December 2020

Abstract
Biological flapping wing fliers operate efficiently and robustly in a wide range of flight conditions and are a great source of inspiration to engineers. The unsteady aerodynamics of flapping wing flight are dominated by large-scale vortical structures that augment the aerodynamic performance but are sensitive to minor changes in the wing actuation. We experimentally optimise the pitch angle kinematics of a flapping wing system in hover to maximise the stroke average lift and hovering efficiency with the help of an evolutionary algorithm and in situ force and torque measurements at the wing root. Additional flow field measurements are conducted to link the vortical flow structures to the aerodynamic performance for the Pareto-optimal kinematics. The optimised pitch angle profiles yielding maximum stroke-average lift coefficients have trapezoidal shapes and high average angles of attack. These kinematics create strong leading-edge vortices early in the cycle which enhance the force production on the wing. The most efficient pitch angle kinematics resemble sinusoidal evolutions and have lower average angles of attack. The leading-edge vortex grows slower and stays close-bound to the wing throughout the majority of the stroke-cycle. This requires less aerodynamic power and increases the hovering efficiency by 93% but sacrifices 43% of the maximum lift in the process. In all cases, a leading-edge vortex is fed by vorticity through the leading edge shear layer which makes the shear layer velocity a good indicator for the growth of the vortex and its impact on the aerodynamic forces. We estimate the shear layer velocity at the leading edge solely from the input kinematics and use it to scale the average and the time-resolved evolution of the circulation and the aerodynamic forces. The experimental data agree well with the shear layer velocity prediction, making it a promising metric to quantify and predict the aerodynamic performance of the flapping wing hovering motion.
Fish-like three-dimensional swimming with an autonomous, multi-fin, and biomimetic robot
Authors: Berlinger F , Saadat M , Haj-Hariri H , Lauder G V , Nagpal R 
Published: December 2020

Abstract
Fish migrate across considerable distances and exhibit remarkable agility to avoid predators and feed. Fish swimming performance and maneuverability remain unparalleled when compared to robotic systems, partly because previous work has focused on robots and flapping foil systems that are either big and complex, or tethered to external actuators and power sources. By contrast, we present a robot—the Finbot—that combines high degrees of autonomy, maneuverability, and biomimicry with miniature size (160 cm3). Thus, it is well-suited for controlled three-dimensional experiments on fish swimming in confined laboratory test beds. Finbot uses four independently controllable fins and sensory feedback for precise closed-loop underwater locomotion. Different caudal fins can be attached magnetically to reconfigure Finbot for swimming at top speed (122 mm s−1 ≡ 1 BL s−1) or minimal cost of transport (CoT = 8.2) at Strouhal numbers as low as 0.53. We conducted more than 150 experiments with 12 different caudal fins to measure three key characteristics of swimming fish: (i) linear speed-frequency relationships, (ii) U-shaped CoT, and (iii) reverse Kármán wakes (visualized with particle image velocimetry). More fish-like wakes appeared where the CoT was low. By replicating autonomous multi-fin fish-like swimming, Finbot narrows the gap between fish and fish-like robots and can address open questions in aquatic locomotion, such as optimized propulsion for new fish robots, or the hydrodynamic principles governing the energy savings in fish schools.
Aspects of CFTs on real projective space
Authors: Giombi Simone , Khanchandani Himanshu , Zhou Xinan 
Published: December 2020

Abstract
We present an analytic study of conformal field theories on the real projective space

R

P

d

, focusing on the two-point functions of scalar operators. Due to the partially broken conformal symmetry, these are non-trivial functions of a conformal cross ratio and are constrained to obey a crossing equation. After reviewing basic facts about the structure of correlators on

R

P

d

, we study a simple holographic setup which captures the essential features of boundary correlators on

R

P

d

. The analysis is based on calculations of Witten diagrams on the quotient space

A
d
S

d
+
1

/

Z

2

, and leads to an analytic approach to two-point functions. In particular, we argue that the structure of the conformal block decomposition of the exchange Witten diagrams suggests a natural basis of analytic functionals, whose action on the conformal blocks turns the crossing equation into certain sum rules. We test this approach in the canonical example of ϕ
4 theory in dimension d = 4 − ϵ, extracting the CFT data to order ϵ
2. We also check our results by standard field theory methods, both in the large N and ϵ expansions. Finally, we briefly discuss the relation of our analysis to the problem of construction of local bulk operators in AdS/CFT.
Technocenosis paradigm sustainability management of a forest enterprise
Authors: Ansary M , Kuzminov A , Ternovsky O , Medvedskaya T , Panyavina E 
Published: December 2020

Abstract
The relevance of the study is associated with the need to provide an effective methodology for the implementation of information technologies in forestry management. The article substantiates for the first time the application of a technocenological approach to enterprise sustainability management in the forest industry. This approach is effective in a variety of products and equipment, provides an account of the important laws of their optimal construction and operation. The technocenological approach allows us to design the structural architecture of the main subsystems of the enterprise, describing it as a certain standard form of the statistical distribution of elements within the boundaries of mathematical stability. This allows using the model as a guide for various management decisions. It is assumed that the proposed formal model will not only increase the manageability of individual enterprises, but also accelerate the digitalization of the entire industry.
Microwave modification of wood: determination of mechanical properties of softwood
Authors: Aksenov A A , Malyukov S V 
Published: December 2020

Abstract
Studies of aspen and birch wood interaction with pulsed exposure to microwave energy have been carried out. A method for determining the effect of microwave energy on the temperature inside the test specimen has been developed. It includes experimental setup for studying heat and mass transfer during drying and heat treatment of wood with microwave energy. Moisture content inside wood specimens has been determined by a new method using a laboratory installation for studying the mechanical properties of wood under the influence of microwave energy. This energy influences on the drying speed of the tested wood specimens. The research enables to select the optimal mode of wood heating by pulsed exposure to microwave energy. The results of wood tests for strength and hardness, obtained under the influence of microwave energy, have revealed the effect of wood hardening. The research has shown that microwave treatment of specimens reduces drying time of aspen and birch wood by five times in comparison with convective treatment.
Forest fire extinguishing: theoretical study of the screw drum parameter influence on the efficiency of a forest fire soil-sweeping machine
Authors: Bartenev I M , Malyukov S V , Malyukova M A 
Published: December 2020

Abstract
Forest fires are studied and developed in all countries with forest resources. However, despite large number of studies, the problem is still far from being resolved and fires still cause great damage to forests. The article deals with research on the influence of the screw drum parameters on the quality of removing the surface soil layer from combustible materials and on the performance of the forest fires soil-sweeping machine. The geometric parameters of the screw drum of the forest fires soil-sweeping machine were optimized. As a result of optimization, the optimal values of the screw channel depth in the range of 7.5-8.7 cm and the screw pitch of 23-40 cm were obtained. At these optimal values, the ground cover content in the thrown soil stream will be less than 15 %, the productivity of the forest fires soil-sweeping machine will be more than 40 kg/s, and the power consumption will be less than 12 kW.
Current issues of the regional forestry planning on the example of the Sverdlovsk region (Russian Federation)
Authors: Theriou N , Pryadilina N , Zinovyeva I 
Published: December 2020

Abstract
The publication addresses the problematic issues of the regional forestry planning. The object of research is the forest sector of the Sverdlovsk region. The subject of research is the mechanism of regional forestry planning. The purpose of the work is to describe the current mechanism of regional forest planning and make individual proposals to improve its functioning. One decade of experience in applying the first forestry plans of the subjects of the Russian Federation have shown their failure. The new forestry plans, developed in the subjects of the Russian Federation using a unified methodology for the period from 2018 to 2029, do not inspire optimism either. The main reasons for the failure of forestry plans are the lack of a scientific concept and the usage of a forest management approach in their development. The conclusions are drawn on a number of organizational and methodological problems associated with the development and implementation of the existing regional forestry planning mechanism, as well as on the need to develop an up-to-date scientifically proven methodological basis for planning in the forest sector at the regional level.
Economic advantages of innovative technologies for accelerated forest regeneration in Russia
Authors: Sijacic-Nikolic M , Ivanova A , Sirotkina N 
Published: December 2020

Abstract
The article discusses the economic benefits of using new technologies for the production of planting material for creating forest plantations. The production costs of creating 1ha forest plantations are identified. A model of the technology of the process of creating forest plantations of fast-growing species, planting material obtained using innovative approaches in the form of contextual diagrams of the main processes is presented. The model organization of the process of creating forest plantations of fast-growing species was created in order to most efficiently use equipment and increase labour productivity. It is proved that the use of planting material obtained using nanotechnological approaches at the stage of microcloning can reduce production costs for creating forest plantations and thus significantly reduce the cost of planting material for plantation cultivation. It has been established that the developed innovative technology for obtaining planting material for creating forest plantations of fast-growing species has economic advantages over the traditional one.
The features designed of mechatronic system of adaptive hopper’s feeder: case study for Scots pine seeds morphometry
Authors: Tylek P , Demidov D N , Lysych M N , Petrishchev E P , Maklakova E A 
Published: December 2020

AbstractThis article will be of interest to engineers involved in designing devices for improving the quality of forest seeds. From the point of view of automated processing, in order to obtain a quality seedling, the seed of the Scots pine must be conditioned, that is, properly graded, and have sufficient ability to germinate in the field, that is, properly sown. It is based on studies of the movement of a single pine seed in the mechanical system of an optoelectronic separator. The experiment was established by measuring the geometric dimensions of samples (n = 500) from a representative sample of a seedlot. ThePinus sylvestrisL. seeds were collected in the Pavlovsky district of the Voronezh region in autumn 2019. Seed samples were measured using a microscope in three mutually perpendicular directions. Seed samples asymmetric shape and an adaptive hopper’s feeder were modeled using SolidWorks software. Our results point to an important feature in the design of loading bins-the need to approximate the complex shape of a single seed of Scots pine with an asymmetric ellipsoid. The need for discrete seed feeding with a frequency no faster than 10−3-10−2s is established to improve both the separation process.
Computer simulation results of modular hydropneumatic suspension of a logging vehicle
Authors: Nikonov V O , Posmetev V I , Posmetev V V 
Published: December 2020

Abstract
The necessity of increasing the efficiency of timber transportation to consumers by timber trucks equipped with traditional dependent suspensions has been substantiated. The analysis of articles made by foreign scientists in the field of research of characteristics of hydropneumatic suspensions of vehicles is presented. A promising design of a modular-type hydropneumatic suspension is proposed. The goal of the work is formulated to develop mathematical and simulation models for the functioning of the proposed construction of a hydropneumatic suspension of a modular type to assess the influence of the main dependences of the nature of oscillations of a timber truck in time on the values of volume, pressure and temperature of air in the cavity of the pneumatic cylinder of the suspension structure. Developed and investigated mathematical and on its basis simulation models of the functioning of the hydropneumatic suspension. The dependences of the vibration frequencies of the body of a timber truck equipped with a hydropneumatic suspension on the vibration spectrum, as well as the time dependence of the volume, pressure and temperature of the air in the pneumatic cylinder when driving over a random uneven surface and single irregularities, are obtained.
Association of complex genotypes of kappa-casein and diacylglycerol O-acyltransferase from milk production in different lines cows
Authors: Efimova I O , Zagidullin L R , Shaidullin R R , Akhmetov T M , Tyulkin S V , Moskvicheva A B 
Published: December 2020

Abstract
The aim of the investigation was to observe the frequency of complex genotypes CSN3/DGAT1 occurrence and their effect on the milk production of different lines cows. It was found that in the herd of cows 4 genotypes CSN3 AA / DGAT1 AK and CSN3 AB / DGAT1 AA, CSN3 AA / DGAT1 AA, CSN3 AB / DGAT1 AK predominate with a frequency of occurrence of more than 7.3%, notably that the greatest number of combinations are found in the lines of M. Chiftein and R. Sowering. The best indices of milk yield (5736 and 5401 kg), milk fat (208 and 201 kg), milk protein (179 and 170 kg) in the lines of V.B. Aydial and R. Sowering were noted in first-calf heifers with the AB/AK genotype. A significant difference (P < 0.05-0.01) in milk yield, fat and protein in the Sowering line was found between the combinations AB/AK and AA/AA, and AB/AK and AB/KK. In M. Chiftein’s line, the highest milk yield (5045 kg), milk fat (182 kg) and protein (163 kg) were detected in the CSN3 BB / DGAT1 AA genotype, when exceeding the combination of AA/AA and AA/AK (P < 0.05-0.01). In high-producing cows V.B. Aydial’s line has the highest milk productivity in cows with the genotype CSN3 AA / DGAT1 AA, when animals with the genotypes AB/AK and AB/KK are exceeded (P < 0.05-0.01).