bluuebunny/crossref_metadata_2025 huggingface dataset:
Embedding public health advocacy into the role of school-based nurses: addressing the health inequities confronted by vulnerable Australian children and adolescent populations
Authors: Jones Debra , Randall Sue , White Danielle , Darley Lisa-Marie , Schaefer Gabrielle , Wellington Jennifer , Thomas Anu , Lyle David
Published: December 2020

There has been a growth in Australian school-based nurses to address the inequities confronted by vulnerable students and school populations. Failure to address inequities can be evidenced in intergenerational poverty, poorer health and educational attainment and diminished life opportunities. School-based nurses are ideally located to advocate for public health policies and programs that address social determinants that detrimentally affect the health of school populations. However, school-based nurses can confront professional and speciality challenges in extending their efforts beyond individual student advocacy to effect change at the school population level. Guidance is required to redress this situation. This paper describes public health advocacy, the professional and speciality advocacy roles of school-based nurses and the barriers they confront in advocating for the health of school populations and strategies that can be used by key stakeholders to enhance school-based nursing public health advocacy efforts. School-based nurses who are competent, enabled and supported public health advocates are required if we are to achieve substantial and sustained health equity and social justice outcomes for vulnerable school populations.
Swear words for sale
Authors: Beers Fägersten Kristy , Pereira Gerardine M.
Published: December 2020

Swearing has traditionally been associated with spoken language; however, swear words are appearing more often in print
and, notably, explicitly featured in commercial products. In this paper, we consider this development an example of the commodification of
swear words, or ‘swear words for sale’. Our analyses of English-language swear word products show that the taboo nature of swear words is
exploited and capitalized upon for commercial gain. We argue that swear word commodities trade on sociolinguistically incongruous aspects of
swear word usage, increasing salability of the swear word products by targeting specific demographics. Specifically, we analyze (1) women’s
apparel and accessories, (2) domestic items and home décor, and (3) children’s products for adults or articles targeting parents of young
children. The study concludes with a discussion of whether the popularization of swearing via such commodification may ultimately result in
a loss of distinctiveness and devaluation.
Why does Lee say what he says the way he says it?
Authors: Zeng Shu
Published: December 2020

This paper employs Kecskes’ socio-cognitive approach to analyze the varied speech styles and cognitive dynamics of the Chinese character (Lee) in John Steinbeck’sEast of Eden. The discussion of the novelistic dialogue segments has shown that the Chinese interlocutor’s verbal strategies vary from pidgin to English or a combination of the two, which are predominantly hearer-centered and marked by deliberate and conscious attempts on the part of the speaker to meet the cooperation principle. Lee’s movement between different communication modes is partly predetermined by the disparate power relations between the interlocutors and partly determined by his own communicative needs, thus producing a unique pattern that governs his language use in the given intercultural communicative process. In particular, pidgin is used as a self-protection mechanism, a buffer and a way of identification by the Chinese character, which informs the wider socio-historical context of Chinese immigrants’ victimization of racial discrimination in the American society at the turn of the twentieth century. Just like his shifting verbal strategies in intercultural communication, Lee’s cultural identity is also characterized by fluidity in the in-between space of two cultures.
Physiological and thermoregulatory effects of oral taurine supplementation on exercise tolerance during forced convective cooling
Authors: Simmonds Richard , Cole James , Tallent Jamie , Jeffries Owen , Theis Nicola , Waldron Mark
Published: December 2020

We investigated the effects of taurine supplementation on cycling time to exhaustion in cold conditions. Eleven males cycled to exhaustion at a power output equivalent to the mid‐point between ventilatory threshold and maximum aerobic power following 15‐min rest in the cold (apparent temperature of ∼ 4°C; air flow of 4.17 m s−1). Two hours before, participants ingested taurine (50 mg·kg−1) or placebo beverage. Pulmonary gases, carbohydrate (CHO) and fat oxidation, body temperatures, mean local sweat rate, heart rate, rate of perceived exertion (RPE) and thermal comfort were recorded. Time to exhaustion was not different between trials (taurine = 14.6 ± 4.7 min; placebo = 13.4 ± 5.6 min, P = 0.061, d = 0.27). There were no effects (P > 0.05) of taurine on core temperature, mean skin temperature or local sweat rates. However, the placebo condition showed greater (P < 0.05) reductions in arm‐to‐finger temperature gradient (i.e. vasodilation) across pre‐exercise passive cold exposure and increased CHO oxidation (P < 0.05). Participants also reached a thermally ‘comfortable’ level quicker in the taurine condition (P < 0.05). A 50 mg·kg−1 dose of taurine did not statistically benefit endurance exercise after moderate cold exposure but conferred some potential vascular and metabolic effects.
Dynamic model for an ensemble of interacting irradiation-induced defects in a macroscopic sample
Authors: Baraglia Federico , Ma Pui-Wai
Published: December 2020

We develop a dynamic model for the evolution of an ensemble of hundreds of interacting irradiation-induced mobile nanoscale defects in a micrometre size sample. The model uses a Langevin defect dynamics approach coupled to a finite element model, treated using the superposition method. The elastic field of each defect is described by its elastic dipole tensor, and the long-range interaction between defects is treated using the elastic Green’s function formalism. The approach circumvents the need to evaluate the elastic energy by means of volume integration, and provides a simple expression for the energy of elastic image interaction between the migrating defects and surfaces of the sample. We discuss the underlying theory, and also the parallelization and coarse-graining numerical algorithms that help speed up simulations. The model addresses the issue of imbalanced forces and moments arising as an artefact of the modified boundary problem associated with the traction free boundary condition. To illustrate applications of the method, we explore the dynamic evolution of an ensemble of interacting dislocation loops of various size and with different Burgers vectors, which proves the feasibility of performing large-scale simulations using the proposed model.
Dislocation precipitate bypass through elastically mismatched precipitates
Authors: Szajewski Benjamin A , Crone Joshua C , Knap Jaroslaw
Published: December 2020

The Orowan bypass mechanism for elastically homogeneous precipitates has been thoroughly studied. In engineering materials, alternate phased precipitates exhibit elastic moduli differing from the host matrix. To further our understanding of realistic dislocation precipitate interactions, we employ a three dimensional coupled discrete dislocation dynamics and finite element computational scheme to compute the Orowan bypass stress (τ
Orowan) required for a dislocation to bypass a row of elastically stiff precipitates. Specifically, we examine the influence of elastic mismatch between precipitates and the host matrix on τ
Orowan. Unique to our computational study, our simulations span a range of precipitate diameters (D), inner precipitate spacings (L), and an order of magnitude in precipitate-matrix elastic mismatch ratio. We partition observed increases in τ
Orowan into dislocation image stress interactions and additional stress concentrations due to the interaction of the applied stress with the elastically stiff precipitates. Finally, we incorporate the dependence of τ
Orowan on precipitate-matrix elastic mismatch into our derived model for τ
Orowan by introducing an effective D which depends explicitly on the elastic mismatch. Both our simulations and analyses suggest that strengthening due to relative increases in precipitate stiffness is modest compared to strengthening with precipitate width.
Unpacking structural domain of mathematics to aid inquiry in physics: a pilot study
Authors: Sokolowski Andrzej
Published: December 2020

Analysing graphs, formulating covariational relationships, and hypothesizing systems’ behaviour have emerged as frequent objectives of contemporary research in physics education. As such, these studies aim to help students achieve these objectives. While a consensus has been reached on the cognitive benefits of emphasizing the structural domain of mathematical apparatus in physics instruction, the question remains open on how to accomplish this task in school practice. This study contributes to this discussion. It attempts to determine how high-school physics students perceive formulas as a means to understand covariational relationships of natural phenomena. It also explores the hypothesis that including more structural domains of mathematics makes physics content more attractive for students. A sample of 25 advanced high-school physics students was taught kinematics, dynamics, and energy sections considering functional representations of some laws and principles traditionally covered in those sections. At the concluding phase, these students were invited to contrast formulas and their covariational embodiments as a means of providing conceptual understanding. The analysis revealed that students considered formulas as algebraic tools to attain a specific value to a particular application or carry out algebraic algorithms to solve a physics problem. They found formulas converted to covariational relationships a better fit for the learning of general phenomenon behaviour and extracting new information, especially from a graphical representation of these relationships. These findings generated the conclusion that the structural domain of mathematics can aid physics understanding by alternatively presenting formulas as mathematical entities that are transferrable to functions. It was further concluded that such parallelism would benefit not only the depth of inquiry in physics but also a general students’ STEM disposition.
Magnetic modeling of actively shielded rotating MRI magnets in the presence of environmental steel
Authors: Whelan Brendan , Leghissa Martino , Amrein Philipp , Zaitsev Maxim , Heinrich Bernhard , Fahrig Rebecca , Rohdjess Heiko
Published: December 2020

Rotating MRI systems could enable novel integrated medical devices such as MRI-Linacs, MRI-xray-angiography systems, and MRI-proton therapy systems. This work aimed to investigate the feasibility of rotating actively shielded superconducting MRI magnets in the presence of environmental steel—in particular, construction steel in the floor of the installation site. Two magnets were investigated: a 1.0 T split bore magnet, and a 1.5 T closed bore magnet. Each magnet was scaled to emulate field strengths of 0.5, 1.0, and 1.5 T. Finite Element Modeling was used to simulate these magnets in the presence of a 3 × 4 m steel plate located 1250 mm or 1400 mm below the isocenter. There are two possible rotation directions: around the longitudinal (z) axis or around the transverse (x) axis. Each model was solved for rotation angles between 0 and 360° in 30° intervals around each of these axes. For each simulation, a 300 mm DSV was extracted and decomposed into spherical harmonics. For the closed-bore magnet, total induced perturbation for the zero degree rotation angle was 223, 432, and 562 μT peak-to-peak (pk–pk) for the 0.5, 1.0, and 1.5 T models respectively (steel at 1250 mm). For the split-bore magnet, the same numbers were 1477, 16747, and 1766 μT. The substantially higher perturbation for the split-bore magnet can be traced to its larger fringe field. For rotation around the z-axis, total perturbation does not change as a function of angle but is exchanged between different harmonics. For rotation around the x-axis, total perturbation is different at each rotation angle. For the closed bore magnet, maximum perturbations occurred for a 90° rotation around the transverse axis. For the split-bore magnet, the opposite was observed, with the same 90° rotation yielding total perturbation lower than the conventional position. In all cases, at least 95% of the total perturbation was composed of 1st and 2nd order harmonics. The presence of environmental steel poses a major challenge to the realization of an actively shielded rotating superconducting MRI system, requiring some novel form of shimming. Possible shimming strategies are discussed at length.
Dynamics of ion beam emission in a low pressure plasma focus device
Authors: Lim Lian-Kuang , Yap Seong-Ling , Nee Chen-Hon , Yap Seong-Shan
Published: December 2020

The plasma that accelerates and compresses in the formation of the pinch in dense plasma focus devices has been found to be an abundant source of multiple radiations like ion beams and x-rays. In this work, the ion beam and x-ray emissions from a 2.7 kJ (13.5 kV, 30 µF) plasma focus device operated at pressure below 1 mbar were investigated. The time profile of the ion beam emission was analysed from the simultaneously measured ion beam, soft and hard x-ray signals using biased ion collectors, BPX 65 silicon PIN diode and a scintillator-photomultiplier tube assembly. Time resolved analysis of the emissions revealed that the emission of the ion beam corresponded to several different pinching instances. Two components of the ion beam were identified. An ion beam of lower energy but higher intensity was emitted followed by an ion beam of higher energy but lower intensity in the first plasma pinch. The ion beam emitted from the first plasma pinch also has higher energy than subsequent plasma pinches. The emission was found to be associated with the amplitude of voltage spike. The results from ion beam and electron beams suggest that they were emitted by the same localized electric field induced in the pinched plasma. The strongest plasma focus discharge indicated by sharp voltage spike of high amplitude and highest ion beam energy were both observed at 0.2 mbar. The average energy of the ion beam obtained is (53 ± 13) keV. At this optimum condition, the ions beam with the highest energy also led to the highest hard x-ray emission.
Particle scattering and resonances involving avoided crossing
Authors: Yang Yu Kun , Cheng Yongjun , Wu Yong , Qu Yi Zhi , Wang Jian Guo , Zhang Song Bin
Published: December 2020

In molecules, the nonadiabatic couplings between two adiabatic potentials build the avoided crossing (AC) region. The rovibronic resonances in the AC region of two-coupled potentials are very special, since they are not in the bound state region of the adiabatic potentials, and they usually do not play important roles on the scatterings and are less discussed. Exemplified in particle scattering, resonances in the AC region are comprehensively investigated. The effects of resonances in the AC region on the scattering cross sections strongly depend on the nonadiabatic couplings of the system, it can be very significant as sharp peaks, or inconspicuous buried in the background. More importantly, it shows a simple quantity proposed by Zhu and Nakamura (1992 J. Chem. Phys.
97 8497) to classify the coupling strength of nonadiabatic interactions, can be well applied to quantitatively estimate the importance of resonances in the AC region. Example applications of the quantity for real molecules (MgH, CO and OH) can well explain the evolutions of cross sections in the AC region published in the literatures. This work provides a simple and practical way to determine the candidate molecules when studying the resonances in the AC region.
Correlated insulating phases in the twisted bilayer graphene*
Authors: Liao Yuan-Da , Xu Xiao-Yan , Meng Zi-Yang , Kang Jian
Published: December 2020

We review analytical and numerical studies of correlated insulating states in twisted bilayer graphene, focusing on real-space lattice models constructions and their unbiased quantum many-body solutions. We show that by constructing localized Wannier states for the narrow bands, the projected Coulomb interactions can be approximated by interactions of cluster charges with assisted nearest neighbor hopping terms. With the interaction part only, the Hamiltonian is SU(4) symmetric considering both spin and valley degrees of freedom. In the strong coupling limit where the kinetic terms are neglected, the ground states are found to be in the SU(4) manifold with degeneracy. The kinetic terms, treated as perturbation, break this large SU(4) symmetry and propel the appearance of intervalley coherent state, quantum topological insulators, and other symmetry-breaking insulating states. We first present the theoretical analysis of moiré lattice model construction and then show how to solve the model with large-scale quantum Monte Carlo simulations in an unbiased manner. We further provide potential directions such that from the real-space model construction and its quantum many-body solutions how the perplexing yet exciting experimental discoveries in the correlation physics of twisted bilayer graphene can be gradually understood. This review will be helpful for the readers to grasp the fast growing field of the model study of twisted bilayer graphene.
Identification of denatured and normal biological tissues based on compressed sensing and refined composite multi-scale fuzzy entropy during high intensity focused ultrasound treatment*
Authors: Yan Shang-Qu , Zhang Han , Liu Bei , Tang Hao , Qian Sheng-You
Published: December 2020

In high intensity focused ultrasound (HIFU) treatment, it is crucial to accurately identify denatured and normal biological tissues. In this paper, a novel method based on compressed sensing (CS) and refined composite multi-scale fuzzy entropy (RCMFE) is proposed. First, CS is used to denoise the HIFU echo signals. Then the multi-scale fuzzy entropy (MFE) and RCMFE of the denoised HIFU echo signals are calculated. This study analyzed 90 cases of HIFU echo signals, including 45 cases in normal status and 45 cases in denatured status, and the results show that although both MFE and RCMFE can be used to identify denatured tissues, the intra-class distance of RCMFE on each scale factor is smaller than MFE, and the inter-class distance is larger than MFE. Compared with MFE, RCMFE can calculate the complexity of the signal more accurately and improve the stability, compactness, and separability. When RCMFE is selected as the characteristic parameter, the RCMFE difference between denatured and normal biological tissues is more evident than that of MFE, which helps doctors evaluate the treatment effect more accurately. When the scale factor is selected as 16, the best distinguishing effect can be obtained.
Delayed excitatory self-feedback-induced negative responses of complex neuronal bursting patterns*
Authors: Cao Ben , Gu Huaguang , Li Yuye
Published: December 2020

In traditional viewpoint, excitatory modulation always promotes neural firing activities. On contrary, the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay are acquired in the present paper. Two representative bursting patterns which are identified respectively to be “Fold/Big Homoclinic” bursting and “Circle/Fold cycle” bursting with bifurcations are studied. For both burstings, excitatory modulation can induce less spikes per burst for suitable time delay and strength of the self-feedback/autapse, because the modulation can change the initial or termination phases of the burst. For the former bursting composed of quiescent state and burst, the mean firing frequency exhibits increase, due to that the quiescent state becomes much shorter than the burst. However, for the latter bursting pattern with more complex behavior which is depolarization block lying between burst and quiescent state, the firing frequency manifests decrease in a wide range of time delay and strength, because the duration of both depolarization block and quiescent state becomes long. Therefore, the decrease degree of spike number per burst is larger than that of the bursting period, which is the cause for the decrease of firing frequency. Such reduced bursting activity is explained with the relations between the bifurcation points of the fast subsystem and the bursting trajectory. The present paper provides novel examples of paradoxical phenomenon that the excitatory effect induces negative responses, which presents possible novel modulation measures and potential functions of excitatory self-feedback/autapse to reduce bursting activities.
X
0(2900) and its heavy quark spin partners in molecular picture *
Authors: Hu Mei-Wei , Lao Xue-Yi , Ling Pan , Wang Qian
Published: December 2020

The

, recently observed by the LHCb Collaboration in the

invariant mass of the

process, is the first exotic candidate with four different flavors, beginning a new era for the hadron community. Under the assumption that the

is a

hadronic molecule, we extracted the whole heavy-quark symmetry multiplet formed by the

doublet and the

meson. For the bound state case, there would be two additional

hadronic molecules associated with the

and

channels, as well as one additional

molecule. In the light quark limit, they are

and

below the

and

thresholds, respectively, which are unambiguously fixed by the mass position of the

. For the virtual state case, there would be one additional

hadronic molecule, strongly coupled to the

channel, and one additional

molecule. Searching for these heavy quark spin partners will help shed light on the nature of the

.
Chiral crossover characterized by Mott transition at finite temperature *
Authors: Mao Shijun
Published: December 2020

We discuss the proper definition for the chiral crossover at finite temperature, based on Goldstone's theorem. Different from the commonly used maximum change in chiral condensate, we propose defining the crossover temperature using the Mott transition of pseudo-Goldstone bosons, which, by definition, guarantees Goldstone's theorem. We analytically and numerically demonstrate this property in the frame of a Pauli-Villars regularized NJL model. In an external magnetic field, we find that the Mott transition temperature shows an inverse magnetic catalysis effect.
Compressional Alfvén eigenmodes excited by runaway electrons
Authors: Liu Chang , Brennan Dylan P. , Lvovskiy Andrey , Paz-Soldan Carlos , Fredrickson Eric D. , Bhattacharjee Amitava
Published: December 2020

Compressional Alfvén eigenmodes (CAEs) driven by energetic ions have been observed in magnetic fusion experiments. In this paper, we show that the modes can also be driven by runaway electrons formed in post-disruption plasma, which may explain kinetic instabilities observed in DIII-D disruption experiments with massive gas injection. The spatial structure is calculated, as are the frequencies which are in agreement with experimental observations. Using a runaway electron distribution function obtained from a kinetic simulation, the mode growth rates are calculated and found to exceed the collisional damping rate when the runaway electron density exceeds a threshold value. The excitation of CAEs poses a new possible approach to mitigate seed runaway electrons during the current quench and surpassing the avalanche.
Application of complex networks and indirect influences to non-forced migration
Authors: Catumba-Ruiz J , Redondo J M , Olivar G
Published: December 2020

The migration phenomena of human populations is a well-known issue in social, economic, and sociophysics studies. A common effect of non-forced migration is the fact that important cities gain population over the first years and become overpopulated. Therefore, neighboring cities receive all migration and end up geographically merging with the important ones. Several studies have addressed the social and economic reasons behind this effect, but a mathematical model has been lacking. Here, we construct a migration complex network with population and migration dynamics and carry out an indirect influences analysis of those dynamics. Using this, we can measure the effect of migration on population growth across cities. The results show that the analysis of the indirect influences reveals interesting facts about the mentioned migration effect and address the measurement of this. Given this, urban planners and city administrations can make use of these findings to improve their migratory research.
Trajectory-tracking control of a planar parallel robot using generalized predictive control with constraints
Authors: Rodelo M , Villa J L , Yime E
Published: December 2020

This paper presents the generalized predictive control with constraints, implemented to a planar parallel robot in order to calculate and track the desired trajectory of the end-effector of this robot. The manipulator is driven by three brushless direct current motors, and each one has an encoder to measure the velocity and rotation angles of the motors. Three constraints were considered to interact with the control law: control signal, terminal response and the over impulse constraints. The performance of the control law is evaluated in the simulation environment using Matlab/Simulink with the physic model developed through simscape multibody. The angular position and velocity errors for each of the three motors were calculated. Likewise, the output torques for each one were estimated. The results proved that the control law proposed with the constraints imposed for each motors has a good efficiency with a stable response time of the robot in performing the trajectory tracking, contributing to the scientific community a strategy of predictive optimization of control actions with multiple constraints applied on parallel robots.
Physical applications: fractional Brownian movement applied to the particle dispersion
Authors: Herrera Y , Prada D A , Ortega J , Sierra A , Acevedo A
Published: December 2020

Fractional Brownian motion allows you to see the correlation between past data increments in a shift with respect to future increments. Through this important physical property of fractional Brownian motion, it was possible to perform an analysis of the impact of suspended particles, also known as particulate matter, on the environment, which is a worldwide concern. The particulate matter produced in a coal mine is large and can be disastrous for neighboring communities, resulting in a decrease in their health and quality of life in general. In this work we analyze a time series of the values of total suspended particles registered by the “La Jagua” monitoring station located 5 km from the coal mine complex in the municipality of “La Jagua” de Ibrírico in Colombia, we do this by using the fractional Brownian motion calculated from Hurst’s coefficient to determine if there is persistence of the presence of this particulate material in the future. Initially a normality test is carried out, then the rescaled range and Hurst coefficient are computed with which it is possible to determine the increasing persistence and volatility of the series.
Development of a system based on aerial images for the morphological patterns classification using support vector machine
Authors: Montero D , Arenas W , Salinas S , Rueda C
Published: December 2020

Oil palm cultivation is one of the major agricultural activities in Colombia. Production performance is related to the good practices in the plantation, mainly regarding the management of phytosanitary conditions. Bud rot disease is the one with the greatest impact in Colombia. The most commonly used technique for its detection is from routine visual inspection on each palm, being costly and inefficient. For this reason, the aim of this study is the development of a classification algorithm based on binary support vector machines for the detection of Bud Rot. The model was obtained from 798 aerial images acquired by unmanned aerial vehicles. Each image was tagged by an expert palm grower based on the presence or absence of the disease. These images were described by 531 morphological features extracted using the concatenation of uniform binary local pattern vectors. Bootstrapping was used to balance the classes, obtaining 507 observations per class. To evaluate the performance metrics of the classifier, an 8-fold Monte Carlo cross-validation was implemented by randomly splitting the data set into training (80%), validation (10%), and test (10%) sets with balanced classes. Finally, the model achieved a performance greater than 96.0%. This indicates that the model developed could be a great technique to automate bud rot detection with high reliability, increasing the efficiency in the recognition. All these thanks to the fusion of Machine Learning techniques with the phenomena of optical physics.
Analysis of the atmospheric macro-physical using spatial methods
Authors: Andrades-Grassi J E , Cuesta-Herrera L , Torres-Mantilla H A , López-Hernández J Y
Published: December 2020

The central western area of Venezuela has an unequal distribution of precipitation. Due to its agricultural importance, is necessary to plan water accounting and this requires a evaluation of spatial and temporal variability of precipitation and an estimate of local geophysical effect from the relief. In this research we use an iterative computationally lattice approach to perform a confirmatory analysis of the variability and the spatial correlation structure in monthly precipitation stations. Spatial correlograms and pooled empirical semivariogram were applied to evaluate the most appropriate spatial weighting matrix to estimate the Moran’s I. The altitude effect over monthly rainfall was estimated through spatial regression algorithm which determine the predominant spatial process in each slice. A homogeneous spatial stochastic process with positive spatial autocorrelation is evidenced. There is a trend towards a higher frequency of spatial error and spatial auto-regressive processes between the months of June and August whilst there are not dominant process between October and December. This response is caused by the dynamics of the intertropical convergence zone, which generates a seasonal effect on precipitation. These estimations allows decision-making in modeling and will lead to an improvement for analysis and forecasting in areas strongly affected by climate change and water stress.
Geometry and measurement: specialized knowledge of future teachers within a pedagogical laboratory
Authors: Acevedo-Rincon J P
Published: December 2020

Based on the need to train teachers for the teaching of school mathematics, it is proposed to carry out a pedagogical laboratory, which allows monitoring successful practices of teachers within the university in order to promote teaching and research processes within the courses. This document aims to analyze the teaching and learning practices of prospective teachers in a didactic course of geometric and metric thinking. In this way, under a qualitative research perspective, the development of the laboratory is analyzed as a process developed in five stages: identification of the population, study of documents, identification of the mathematical object, planning, implementation and reflection and systematization of the experience. This article contributes mainly to the representation of phenomena and proposal of models of physics and natural sciences. One of the main conclusions proposes training for the teaching of school mathematics with real experiences given by natural contexts where pedagogical practices are carried out. From these practices, the reflections made by the students reveal the contributions of adequate planning of the classes for the success in the development of this, in addition to the security that these practices generate when taking classes from non-own courses.
Scientific competencies around the study of physics in secondary school students. A review of knowledge
Authors: Hernández-Suárez C A , Prada-Núñez R , Avendaño-Castro W R
Published: December 2020

This research seeks to analyze the degree of promotion and development of scientific competences based on the document Basic Standards of Competences in Natural Sciences proposed by the Ministerio de Educación Nacional, Colombia, specifically the competences associated with Physics. To this end, a twenty-item questionnaire is designed with a dichotomous response scale. The reliability analysis showed that the proposed scale had a good internal consistency regarding the measurement of scientific competences. The research adopts a quantitative descriptive approach based on the processing of data provided by 87 students from a private educational institution with emphasis on natural sciences in the city of San José de Cúcuta and enrolled between the ninth and eleventh grades. The results identify as a weakness in the teaching process, that teachers do not promote the use and articulation of diverse registers of semiotic representation of a set of data, a situation that limits the process of reasoning and resolution of problematic situations in everyday scenarios where the concepts of physics are present. Likewise, it was observed as a strength that teachers promote attitudinal skills in their students based on mutual respect, cooperative work and good communication. This type of research expands the knowledge that is available on the process of developing scientific competencies in the courses prior to entering higher education, so it is suggested to replicate this research process in students from different social contexts in order to improve the robustness of the questionnaire and provide valuable information to educational institutions on the design of improvement plans.
The ways to improve the interaction between executive authorities and business entities in the sphere of forestry
Authors: Kolesnichenko E , Panyavina E , Sokolinskaya Yu , Netrebskaya O
Published: December 2020

The effective development of the forestry sector mainly depends on the specifics and ways of interaction between business entities and the bodies of government, since the land resources are owned by the state. The authors analyzed the normative legal acts regulating the interaction between the state and business entities in the sphere of forestry. They also systematized and analyzed the factors that determine the effectiveness of this interaction. Taking into account the activities of the government bodies and enterprises, the authors paid special attention to differentiation and systematization of the factors. After applying the interview method, organizing a brainstorm and carrying out the hierarchy analysis, the authors concluded that the economic factor is the most important. The authors formulated a number of recommendations concerning the regulatory and legislative support as well as the infrastructure provision and the support for small and medium-sized enterprises. The authors generalized a lot of analytical, research and legislative material to give an idea of the modern forms and methods of interaction between the executive authorities and business entities in the sphere of forestry. Apart from that, the authors analyzed the interaction of the mentioned structures in the sparsely wooded areas.
Introduced poplar varieties and new hybrids for protective afforestation
Authors: Tsarev A , Tsareva R , Tsarev V , Miligula E , Lenchenkova O
Published: December 2020

The volume of actual protective forest stands in the Central Chernozem Region is presented, and the need for their additional creation is shown. It is noted that in recent years, side by side with the main forest tree species competitive cultivars of euramerican poplars varieties and some new hybrids obtained by domestic breeding have been introduced in the forest shelter belts and protective stands, which in the reclamation fund of the Voronezh region reached a height of 15 m at 20 years, 25 m at 30 years and 30 m at 42 years. After many years of testing in various soil and climatic environments of the region the selection of promising poplars varieties, hybrids and clones for protective afforestation was carried out. The following euramerican cultivars have been recommended: ‘Vernirubens’, ‘Robusta’, ‘Regenerata’, ‘Sacrau-59’ etc. From domestic hybrids ‘Pioneer’ and ‘E.s.-38’ (Elite seedling No. 38) can be recommended, which grow well in the floodplain conditions in dry steppe zone in Volgograd region. At 30 years, they reached a height of 24-25 m; and diameter – 28-31 cm. For comparison, similar growth indices (height about 20 m, diameter – 28-30 cm) oak shelter forest plantations in Kamennaya Steppe reached only by the age of 75 years.
New technology for encapsulating conditioned seeds to increase aerial seeding efficiency
Authors: Vovchenko N , Novikov A , Sokolov S , Tishchenko E
Published: December 2020

Study refers to the field of forestry, in particular, to technologies that ensure the encapsulation of seeds for aerial sowing during reforestation in areas inaccessible or ineffective for ground mechanization. The existing approaches today have a number of significant disadvantages: increased injury to seeds and the impossibility of subsequent directive sowing; insufficient density of the capsule outer shell for aerial seeding, allowing only surface aerial seeding; high complexity and laboriousness of execution, which does not allow its implementation in the field. Based on a systematic and patent search, the existing technologies for producing capsules, including freezing seeds, have been analyzed. The result is developed and patented sequence of operations, the effectiveness of using which in aerial seeding is confirmed economically. Its advantages are simplicity, increasing the accuracy of aerial seeding by ensuring the aerodynamic stability of the capsules in flight and increasing the protection of seeds in contact with the soil by placing the seeds inside the capsules. However, a number of questions remain for future research: how does the drop height and soil condition affect the strength and proportions of the capsules? How does the physical-chemical composition solution on the strength and proportions of capsules?
The influence of heavy metals in the green zone oak coppice on the fertility of Neuroterus numismalis Fourc and Diplolepis quercus folii L.
Authors: Tylek P , Kazbanova I
Published: December 2020

The problem of pollution effect on insects requires careful research. It is necessary to work out ways to reduce this impact on insects, if the pollution does not aim to destroy it. The purpose of the study was to investigate the effect of heavy metals on the species composition and population of Cynips (Neuroterus numismalis and Diplolepis quercus folii) in the overgrown oak forests of green zones. The main test - the object was a Neuroterus numismalis and Diplolepis quercus folii. The main research was carried out in coppice oak forests of the green zone of Voronezh (Russian Federation) in the Pravoberezhnoye forestry in quarters 33 and 35 along the M-4 “Don” highway. The ability of a Neuroterus numismalis to selectively populate oak leaves with an increased concentration of heavy metals puts it in the category of the most effective bio-indicators among the Cynips. The gall of the Diplolepis quercus folii is most susceptible to chemical contamination. With a low level of chemical contamination, the fecundity of the Diplolepis quercus folii and Neuroterus numismalis reaches a maximum level and decreases (in the Neuroterus numismalis one more sharply) with an average level of pollution.
Closed-loop economic model formation in the forest industry
Authors: Allegret J-P , Yakovleva E A , Titova E V
Published: December 2020

The article is devoted to solving the problems of constructing a closed-loop model in the forest industry. The transition to a circular economy requires introduction of innovations in production based on a long life cycle of goods and resources, restoration, reconstruction, the possibility of joint consumption and processing. An urgent problem is the organization of utilization and processing of waste from the forest industry, since this leads to the conservation of primary wood material and significantly reduces the amount of deforestation. The aim of the study is to assess the level of implementation of closed cycles in the forest industry to conserve natural resources, to ensure the protection of people and the environment in production and management. The key role in substantiating the results of the study was provided by the scientific methodology for studying socio-economic phenomena and processes, methods of systemic, criteria-based, institutional analysis, empirical generalization, and a normative approach. To simulate the development of cyclic development, economic opportunities are identified that allow involving additional resources in the secondary circulation, reducing the volume of burial and burning of wood waste, and reducing harmful environmental consequences. The circular forestry model requires government action to overcome institutional, economic and political barriers.
Adaptive milling of solid wood furniture workpieces: analysis of the extended approach capabilities
Authors: Starikov A , Gribanov A , Lapshina M , Mohammed H
Published: December 2020

An extended approach to improve adaptive milling of solid wood workpieces is described. It is based on the joint usage of two physically different methods: non-contact ultrasonic scanning of the workpiece body and optical recognition of the wood fibers direction on the workpiece surface. To implement the proposed approach, it is necessary to change the existing technological route of furniture workpieces processing. A stage before the milling operation should be included. This stage involves the sequential execution of ultrasonic scanning, computer processing, and optical recognition of the obtained data. It allows us to determine the wood density, the internal defects localization, and the direction of wood fibers. Computer processing involves the usage of a virtual orthogonal grid. This grid covers the workpiece surface, on which the trajectory of the milling cutter is projected. The projection of the milling path is represented by the set of cells. It defines the local processing area. The gathered information about the wood properties is suggested to use for the adaptive selection of the important equipment technological parameters, such as the feed rate and the cutter rotation frequency. Varying of these parameters values and considering the physicomechanical properties of wood at the processing area allow us to improve the milling quality.
Estimated parameters of species participation in recreation (Voronezh, Russia)
Authors: Degtyareva S , Dorofeeva V
Published: December 2020

A series of sample plots have been laid to study the influence of recreational load in general and in grassy ground cover in Central Park of Culture and Leisure of Voronezh, Arboretum of Voronezh State University of Forestry and Technologies named after G F Morozov. We used qualitative (structural biodiversity) and quantitative (relative projective cover, abundance and constancy) estimation parameters as indicators of the species’ participation in the formation of plant associations using two urban ecosystems as an example. The aforementioned arboretum and park belong to the forest-park part of the city green zone. Tracing of flora synanthropization is very important here. Species abundance is generally higher in the arboretum (226 species), but grass cover is not numerous (31 species) due to timely economic activities. By quantitative parameters, on the contrary, grasses of broad-leaved forests prevail in the grassy cover of the Park: ashweed (Aegopodium podagraria L.) with projective cover (40-44.6%) and sedge (Carex pilosa Scop.) - 19.8% -29.6 % (1-2 stages of recreation, respectively). The class of abundance of these dominant species raises to 3 (1-2 for other species). The analysis of the constancy class, on the contrary, has not revealed clear species attachment to certain test plots.
Aspects of modeling the main production processes of wood enterprises
Authors: Oleinik E B , Popov E V , Rogulin R S
Published: December 2020

This article describes the main production processes at forest industry enterprises. The container has free space for the process of goods delivery, which enables customs inspection with partial unloading of goods. This enables to have enough time to inspect the container. It is believed that the costs associated with carriers are increasing. The ratio of free and occupied space when loading a container is not obvious. Two approaches to process modeling have been considered. The methods and algorithms for transport processes simulating have been presented. A solution to the problems of optimal container loading during customs control has been proposed. A simulation model of roundwood transportation across the borders has been implemented, which enables to determine the optimal loading volume of containers in order to minimize the time for customs clearance. The proposed option of partial loading reduces the time of customs inspection, which significantly reduces the costs associated with transportation of timber products, as well as the risk of customer refusal from the products delivered out of schedule.
Histological changes in the structure of one-year sprouts of Pinus sylvestris L. as a reflection of the structural adaptation of the species during its introduction
Authors: Galdina T , Khazova E
Published: December 2020

Comparative anatomical studies of one-year sprouts Pinus sylvestris L. made it possible to obtain data on the features of vegetative organ formation, histological changes and the persistence of structural features by the influence of environmental factors. It is noted that the parameters of histological structure and cytological indexes of one-year sprouts are strongly influenced by the hydrothermal coefficient (HTC) of growing conditions. The structure of the one-year sprouts of Pinus sylvestris L., growing in sufficient humidification (HTC=1.6) conditions, is characterized by the greatest thickness of cortex, phloem and xylem, the largest radius of pith, the maximum diameter of resin canals, while having the smallest size of external protective tissues. Histological studies of the geographical cultures of Pinus sylvestris L. of the central forest-steppe revealed, that being in the same growth conditions, the anatomical structure of one-year sprouts significantly changes. Histological and cytological indexes of the anatomical structure of the one-year sprouts of Pinus sylvestris L. populations from the dry steppe increase by 33%, from the broad-leaved forest zone decrease to 30%. Thus, structural adaptation of the assimilation apparatus to new growing conditions occurs, which determines in general the productivity and stability of the woodlands of Pinus sylvestris L.