bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method using 4D dose accumulation to quantify the interplay effect in lung stereotactic body radiation therapy
Authors: Huesa-Berral Carlos , Burguete Javier , Moreno-Jiménez Marta , Diego Azcona Juan 
Published: December 2020

Abstract
The purpose of this study was to devise and evaluate a method to quantify the dosimetric uncertainty produced by the interplay between the movement of multileaf collimator and respiratory motion in lung stereotactic body radiation therapy. The method calculates the dose distribution for all control points from a dynamic treatment in all respiratory phases. The methodology includes some characteristics of a patient’s irregular breathing patterns. It selects, for each control point, the phases with maximum and minimum mean dose over the tumor and their corresponding adjacent phases, whenever necessary. According to this selection, the dose matrices from each control point are summed up to obtain two dose distributions in each phase, which are accumulated in the reference phase subsequently by deformable image registration (DIR). D
95 and

D

min
,
0.035
cc

were calculated over those accumulated dose distributions for Gross Tumor Volume (GTV), Planning Target Volume—based on Internal Target Volume approach—and Evaluation Target Volume (ETV), a novel concept that applies to 4D dose accumulation. With the ETV, DIR and interplay uncertainties are separated. The methodology also evaluated how variations in the breathing rate and field size affects the mean dose received by the GTV. The method was applied retrospectively in five patients treated with intensity modulated radiotherapy—minimum area defined by the leaves configuration at any control point was at least 4 cm2. Uncertainties in tumor coverage were small (in most patients, changes on D
95 and

D

min
,
0.035
cc

were below 2% for GTV and ETV) but significant over- and under-dosages near ETV, which can be accentuated by highly irregular breathing. Uncertainties in mean dose for GTV tended to decrease exponentially with increasing field size and were reduced by an increase of breathing rate. The implementation of this method would be helpful to assess treatment quality in patients with irregular breathing. Furthermore, it could be used to study interplay uncertainties when small field sizes are used.
Principles and impacts of dynamic threshold voltage in a p-GaN gate high-electron-mobility transistor
Authors: Wei Jin , Xu Han , Xie Ruiliang , Chen Kevin J 
Published: December 2020

Abstract
GaN power transistors are attracting increasing attention for next-generation power switching applications. However, GaN power transistors should not be regarded as a direct replacement for silicon power metal–oxide–semiconductor field-effect transistors, since the unique properties of GaN power transistors require special treatment. In this work we review a unique and critical property of GaN power transistors, the dynamic threshold voltage (V
th). GaN power transistors feature a p-GaN gate structure, while the gate metal contacts the p-GaN layer through a Schottky junction. This unique p-GaN gate structure is distinctively different from the silicon metal–oxide–semiconductor gate structure in that the p-GaN layer is actually a floating region without direct electrical contact to the external electrodes of the device. The floating p-GaN layer enables a charge storage process during the switching operation of a p-GaN gate high-electron-mobility transistor. Through carefully designed experiments, the strong correlation between charge storage and the dynamic V
th shift has been revealed; this also serves as an approach to accurately predict the dynamic V
th during switching operation. The influence of the dynamic V
th on power switching applications is discussed. For example, with a positive dynamic V
th shift, the reverse conduction voltage of a GaN power transistor is significantly increased, adding to the power loss. This positive V
th shift also demands a sufficiently high gate drive voltage to ensure that the GaN power transistor can be fully turned on, which reduces the safety margin for the gate reliability of the device. To design a GaN based power switching circuit, accurate simulation of the device/circuit characteristics is necessary. Circuit simulations that do not consider the dynamic V
th lead to a large deviation from the measurement circuit characteristics. We demonstrate that by incorporating the dynamic V
th into the circuit model this deviation can be effectively eliminated.
Programmable self-foldable films for origami-based manufacturing
Authors: George Derosh , Madou Marc J , Peraza Hernandez Edwin A 
Published: December 2020

Abstract
Manufacturing of three-dimensional structures of millimeter and sub-millimeter sizes is required in emerging applications in microelectronics, packaging, and particle entrapment. This paper presents a manufacturing method for three-dimensional polyhedral structures at such scales enabled by programmable, self-foldable polymer films. The manufacturing method starts with a three-dimensional target shape and uses origami design to generate the outline and fold pattern of a planar film that can be folded towards the target shape. Double-exposure photolithography is employed to pattern a polymer film based on the generated geometry along with stiff faces of high crosslinking density and flexible folds of low crosslinking density. During the development step of the photolithography process, the folds absorb the developer solution from one side, creating a concentration gradient across their thickness. The non-uniformly absorbed developer in the folds is evaporated when the film is heated, causing non-uniform strains across their thickness and enabling self-folding. It is experimentally determined that the fold angles exhibited by the folds are directly proportional to the ratio between their width along the folding direction and the film thickness, which enables programming of the folding response through modulation of the fold dimensions. Different structures are fabricated to demonstrate the effectiveness of the developed manufacturing method.
Failure analysis of self-healing epoxy resins using microencapsulated 5E2N and carbon nanotubes
Authors: Zamal Hasna Hena , Barba David , Aïssa Brahim , Haddad Emile , Rosei Federico 
Published: December 2020

Abstract
Investigation on self-healing properties of epoxy containing microcapsules of pure 5-ethylidene-2-norbornene (5E2N) and mixed multi-walled carbon nanotube (MWCNT) suspension is presented in this work using lap shear and mode I fracture tests. While both systems show significant self-healing functionalities between 39% and 97%, those repaired with MWCNT/5E2N microcapsules are found to have mechanical recovery efficiencies two times higher than those containing 5E2N alone, under different types of loading. MWCNT/5E2N microcapsules are also found to improve the physical strength of the epoxy matrix much higher than microcapsules containing only 5E2N. Compared to self-healing epoxy systems made of 5E2N microvessels, the dispersion of 0.10 wt.% of only MWCNTs inside the encapsulated monomer increases the lap shear strengths of the pristine materials and the self-healing materials tested after one fracture/curing cycle, by about 50% and 250%, respectively. Using fractographic observations, Raman spectroscopy and scanning electron microscopy, we observe the occurrence of a ring opening metathesis polymerization reaction and the contribution of MWCNTs to strengthening the material. The present work indicates that the MWCNT/5E2N microcapsule when incorporated into an appropriate epoxy formulation can serve as efficient self-healing matrix material for laminated composites, as well as self-healing structural adhesives for composite bonded joints, two features that make this system highly relevant for applications in aerospace engineering.
Hybridized nanofluid with stagnation point past a rotating disk
Authors: Ahmad Shafiq , Nadeem Sohail 
Published: December 2020

Abstract
Hybrid nanofluid is a mixture of two different nanoparticles that offer better heat transfer performance and thermophysical properties than traditional heat transfer fluids (water, oil, and refrigerant-134A) and nanofluid with single nanoparticles. Here, a type of hybrid nanofluid containing single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs) nano-sized particles with water and refrigerant-134A as base fluid is analytically modeled to establish the problem of the steady laminar MHD stagnation-point flow of a SWCNT–MWCNT/water-refrigerant-134A hybrid nanofluid through a rotating disk. Further, the influence of partial slip, viscous dissipation, and thermal slip are examined. Variables of von Karman are being used to transform partial differential equations in ordinary differential equations, which are solved numerically applying boundary value problem solver (bvp4c) in the MATLAB software. A comparison table for specific cases is provided to see the accuracy of our numerical results with recent data. The velocity and temperature behavior are plotted for various parameters. It is perceived that the fluid temperature is higher for hybrid nanofluid as compared to simple nanofluid and reverse behavior is observed for radial velocity. Further, the azimuthal velocity diminishes with the increasing value of magnetic and velocity slip parameters.
CuO nanoparticles effects on poplar×aspen hybrid clones at various stages of microclonal propagation
Authors: Zakharova O , Kolesnikova E , Kolesnikov E , Yevtushenko N , Morkovin V , Gusev A 
Published: December 2020

Abstract
We have studied the effects of CuO nanoparticles with the mean lateral dimension 300×500 nm and thickness about 50 nm on hybrid poplar×aspen clones at various stages of micropropagation. It has been established that CuO nanoparticles display a strong sterilizing activity and enhance rhizogenesis in microplants. At the culture establishment stage exposure to 1.5 - 3 μg/L CuO increased the number of leaves and roots, and stimulated the root system development. At 15 μg/L had an inhibiting effect on the studied parameters. At the multiplication stage we observed a considerable decrease in the height of shoots, and thickness of leaf lamina and stem diameter. At the same time a significant increase in the regenerants survival rate was observed (+20%), together with improved rhizogenesis. During the rooting stage, a 30% increase in the number of microclones with roots was detected, as well as a twofold increase in the number of roots on each plant. Besides, the nanomaterial had a stimulating effect on the shoots growth, increasing their height by 25%.Thus, it has been established that CuO nanoparticles produce differently directed effects on the growth and development of poplar×aspen hybrid microclones, depending on the micropropagation stage.
Survival rate of the Crimean pine forest cultures (Pinus pallasiana D. Don) created by non-standard seedlings on Don hilly sands
Authors: Turchina T A , Bannikova O A 
Published: December 2020

Abstract
Experimental forest cultivations of Crimean pine were produced on cohesive-sandy soils with hilly terrain to show the possibility of using non-standard seedlings. The minimum height of the seedlings was 10 cm (a standard indicator) compared to 2.0…2.9 cm – the stem diameter at the root collar (a non-standard indicator). In an experiment the agronomic technique of preplant treatment of the seedlings’ root systems with a solution of Kornevin (a biostimulant, Agrosintez, Russia) was used. When creating forest cultures by hand planting, the differences between the experimental options in terms of the survival rate and the nature of variation depending on the quality of the seedlings used were not significant (actual Student’s and Fisher’s coefficients is less than tabular). Treatment of root systems with Kornevin solution contributed to a more even distribution of the plants in the area. Mechanized planting did not provide for a high survival rate of forest cultures (the rate was 58.4% in the 1st year and 37.3% in the 3rd year), while the surviving plants did not form a homogeneous population (variation factor 30.5…71.0). The results indicated that it was possible to use seedlings of non-standard sizes in renewal after treating root systems with solutions of root stimulants.
Modeling of light propagation in a wood polymer-sand composite
Authors: Storodubtseva T , Bondarev B , Sadrtdinov A 
Published: December 2020

Abstract
The subject of the research is wood polymer-sand composite (WPSC) and study of its physical and mechanical properties. In this case it is propagation of light in the material using simulation and development of a computer program to simulate the propagation of UV radiation in WPSC block. A separate computer program in the Object Pascal language was compiled to study the model. The program is designed to simulate two-dimensional approximation of infrared, visible, ultraviolet radiation propagation in wood polymer-sand composite. The program is applicable in a wide range of concentrations of the composite components, for different optical absorption coefficients of the components, depending on the wavelength of the radiation. Concentrations, optical properties of the components, and lighting conditions can be specified in the text of the program. The results of the program are the structure of the composite as a random uniform distribution of wood and sand fragments in a polymer matrix, a cartogram and a graph of the intensity distribution in the composite specimen. The result has been obtained: penetration depth of destructive UV radiation is about 1.5 mm at an optimal concentration of the components CW=45%, CPI=35%, CSa = 20%.
Theoretical research of the work of technological equipment for lifting large planting material with a soil clod
Authors: Drapalyuk M V , Druchinin D Yu , Pozdnyakov E V 
Published: December 2020

Abstract
Large woody plants are a promising type of planting material for use in landscaping and forestry. The most labor-intensive technological operation in the process of growing them is lifting. To increase efficiency, this type of work must be performed using special equipment. The aim of the study is to study the process of plantlets lifting with a soil clod based on mathematical modeling methods to determine the optimal design parameters of lifting equipment developed by the authors. For a theoretical study of the equipment working process, a mathematical description of the interaction of the digging working tool with the soil-plant environment is carried out. The research work with the model consisted in the implementation of computer experiments to solve the compiled differential equation of the working tool motion around a fixed axis. Moreover, within the framework of changing the parameters of the working tool and the medium being processed, the dependences of the moments created by the driving forces and resistance forces are recorded. According to the results of the study, patterns of changes in the power characteristics of the digging process were established depending on the parameters of the working tool and the soil-plant environment.
Analysis of the information content of tenders for the removal of unwanted vegetation
Authors: Ersson B T , Platonov A , Zimarin S 
Published: December 2020

Abstract
To ensure the safe functioning of transport infrastructure facilities on their territory a set of works is carried out to remove unwanted trees and shrubs. The aim of the study is the formation of objective information about the most popular technological operations during the performance of these works and the development of recommendations on its basis for production. The methodological basis of our research was a complex of methods of logical, statistical and comparative analysis. Researchers analyzed more than 8,100 competitive bids for the removal of unwanted vegetation, according to a number of criteria. It was revealed that in 18.8% of the competitive bids, the technical task was completely absent, in 40.8% there was no mention of the necessary machines / mechanisms, in 66.4% there was no information about the necessary technological process for influencing unwanted vegetation, while the minimum 30% of the work involves only a manual way to remove it. The analysis of the distribution of the names of works by the relative demand coefficient is carried out, the expediency of reducing their nomenclature is established. The results of the work can be used by manufacturing enterprises engaged in the maintenance and operation of transport infrastructure facilities.
Reduction of dynamic loads on the hydraulic drive of forest boom lifter
Authors: Glushkov S , Popikov P , Chetverikova I , Druchinin D 
Published: December 2020

Abstract
The article is devoted to the reduction of dynamic loads on hydraulic drive by optimization of hydraulic cylinder for boom lifting and parameters of new damping device. A mathematical model of the working process of the boom lifting mechanism of serial hydraulic manipulator LV-184A has been solved. The optimal position of the hydraulic cylinder, in which the fluid pressure is reduced from 12.4 MPa to 11.3 MPa, has been found. It takes into account the forces of inertia and compliance of hydraulic drive. Connecting a new damper reduces the maximum pressure in the piston cavity of the hydraulic cylinder by 47%. The minimum of maximum values of the working fluid pressure is achieved when the damper throttle channel diameters are in the range of 4.0–4.5 mm. The aim (reduction of dynamic loads) is achieved by optimizing the configuration of the boom lift cylinders and the parameters of new damper. It significantly increases reliability of hydraulic drive elements and efficiency of manipulator-type machines in forestry complex.
Condition assessment of species of the genus Pseudotsuga Carr in Voronezh in order to predict seed productivity in the urban environment
Authors: Chekmeneva Yu V , Dorofeeva V D 
Published: December 2020

Abstract
In the conditions of the Central Black Earth region, in the park plantations of the city of Voronezh, the categories of tree conditions and seed productivity of the genus Pseudotsuga Carr were compared. Estimated yield, linear parameters of cones and seeds. The average values and the amplitude of the variability of the morphometric parameters of cones and seeds are determined. It was shown that in urban conditions at different objects the variability of attributes increases and the category of condition worsens for trees that grow in close proximity to roads, and are also in a depressed state due to shadowing by neighboring trees. The possibility of phenotypic selection of trees for stability in an urban environment by the level of variability of the parameters of the generative sphere is considered. It was revealed that variability at the level of cultivated phytocenoses is weakly expressed than that of individual trees at the endogenous level. In this regard, selection requires a more in-depth study of the polymorphism of cones and seeds to identify correlative traits associated with tree productivity indices.
Heavy metals in soils under various tree species
Authors: Kramareva T N , Gorbunova N S , Tikhonova E N , Gromovik A I 
Published: December 2020

Abstract
The issues of mutual influence of forest and soil attract the attention of researchers not only in theory, but also in practice, especially in the forest-steppe and steppe regions of the country. The researchers drew attention to the rapid changes in soil properties associated with forest planting. In addition, the composition and properties of soils are affected by the rock composition of forest belts. The main chemical, physical, and physical-chemical properties of ordinary chernozems under forest stands, of different rock composition, were studied. The same indicators were investigated in the chernozems occupied by arable land. It is shown that protective forest strips do not significantly affect the physical properties of soils. Chemical and physical-chemical properties change under the influence of wood crops. The gross content and mobile compounds of heavy metals in chernozems occupied by tree species were studied. It is shown that various HM and their compounds have their own characteristics of content and intra-profile distribution. The content and distribution of heavy metals is determined by the pH value, the content and distribution of silty particles, and humus (Corg). In addition, the nature of vegetation and various types of wood species have a significant impact on the content and profile distribution of heavy metals.
Post-fire successions in protected mountain forests of Crimea
Authors: Levchenko K , Matveev S , Konstantinov A 
Published: December 2020

Abstract
Forest fires are one of the most powerful factors, not only in Russia, but all over the world. It affects the structure of ecosystems and causes the landscape transformations in it. In Crimea, the ‘Krymskiy’ National Park, where research was conducted, is a major keeper of population natural forests. Post-pyrogenic changes in vegetation cover were studied in pine phytocenoses (Pinus sylvestris L., Pinus pallasiana D. Don.) and juniper phytocenoses (Juniperus communis subsp. hemisphaerica C. Presl., Juniperus sabina L.). The investigated areas were covered by fire different intensivity 2-37 years ago. It was found that the surface fires damages all elements of the forest phytocenosis. The juniper forests burn down completely and have not recovered in a period of up to 20 years. Forest fires cause secondary post-fire (pyrogenic) regressive succession in the mountain forests of Crimea. Herbaceous plants appear on the investigated sample areas where the forest is burnt: violent competitor plants (K-plants); stress-resistant plants (C-plants) and ruderal plants (P-plants), as well as – plants-pyrophytes. In the first years after a forest fire, the herbaceous plant community is more diverse and aligned. In subsequent years, the number of species decreases, and the index alpha plant diversity value also decreases.
Change of Quercus robur L. acorns seedlings cytogenetic parameters under anthropogenic impact
Authors: Popova A , Popova V 
Published: December 2020

Abstract
Long-term dynamic of cytogenetic parameters of the seedlings apical root meristem was analyzed for the Quercus robur for Central Black-Soil region. Central Black-Soil region located in the European part of Russia (geographical coordinates for Voronezh city: 51.660781; 39.200269) in the temperate climate zone. Annual climate indicators were analyzed to determine the possible influence of precipitation amount and temperature fluctuations during pollination and seed formation in the parent trees. Seed progeny cytogenetic parameters of trees growing in urban and suburban conditions were characterized by an increase in mitotic activity and the proportion of cells with mitotic pathologies, the appearance of micronucleus and residual nucleoli in mitosis. There was possible consequence of the complex technosphere negative factors impact on populations. The mitotic index for urban populations (from 6.8% to 9.5 %) was approximately at the same level for all years in long-term dynamics. There was a sharp decrease in mitotic activity (4.6 %) for the control area in 2019 compared with the data for 2008 (10.5%). The proportion of cells with mitosis pathologies in the meristems of urban seedlings was increased. There was a significant prophase-cells proportion increase among the seedlings. The reduction of number of pathologies may indicate the check-point repair system operation.