bluuebunny/crossref_metadata_2025 huggingface dataset:
TAMIḺMOḺI ILAKKAṆAC CIṞAPPUKAḶ ŌR ĀYVU [NUANCES OF GRAMMAR IN TAMIL LANGUAGE]
Authors: BALAKRISHNAN LEKHAADEVI
Published: October 2021

There is no book that states the grammatical attribute of tamizh literature more elegantly than Tolkāppiyam. Tolkāppiyam is one of the oldest Tamil literature which was written in the third century by Tolkāppiyar. Tolkāppiyar divided Tolkāppiyam into three chapters: letters (Eḻuttu), word (Col), and meaning (Poruḷ). The first chapter is letters (Eḻuttu). The noun (Eḻuttu) is made out of the verb (ezhu). Even though the word ezhu can come with various meanings, in this case it indicates something that has taken shape. Tolkāppiyar has divided the grammar of letters into two different types: The First (Muthal) and The Dependant (Charpu). The First type letters can be divided into two more types which are vowels (Uyir) and consonants (Mei). The vowels (Uyir eḻuttu) also can be divided into two types called (kuril) which produce short sounds and (nedil) which produce long sounds. The consonants have their own types, which are (Valliṉam), (Melliṉam) and (Iṭaiyiṉam). Valliṉam letters produce hard sound while melliṉam consonants produce soft sound and iṭaiyiṉam consonants produce medium sound. Moving on from the The First letters type, The Dependant type letters can be divided in three types: (Kuṟṟiyalukaram), (Kuṟṟiyalikaram), (Āyutam). Besides Tolkāppiyar, Agathiyar also have described the grammar of tamizh literature very precisely. Agathiyam which written by Agathiyar describes grammatical features of letters (Eḻuttu), word (Col), meaning (Poruḷ), consecration (Yaappu), team (Ani).
TAMIḺMOḺIK KAṞṞAL KAṞPITTAL [TEACHING TAMIL LANGUAGE LEARNING]
Authors: P. BHAKKIALAKSHMI
Published: October 2021

This study shows that in this prevailing lifestyle and system of education, our younger generations of elementary students are far behind in reading and loving their mother tongue. Therefore, the need for new approaches in the teaching of Tamil language learning to change this situation, the qualifications of language teachers, and the role of language teachers in developing the ability of students is highlighted in this research. This topic initially deals with the characteristics of a good teacher, which should be based on languages, new ways to recall the learned content to the students, methods that a teacher should improve themselves, and some new approaches to teaching lessons. This study is based on the texts. The primary texts of this study are Language Teacher Characteristics and Language Training, New Approaches in Teaching Tamil Way Part-1, Tamil Teaching. The role of language teachers in improving the skills of students and in simplifying the understanding of the difficult nature of education is also evident. It is expected to be very helpful to language teachers in teaching Tamil language learning. The teaching techniques used by the ancestors and the teaching techniques relevant to the contemporary context are mentioned. We must properly teach our students the pride and usage of the language.
TIRUMANTIRATTIL UPATĒCAM [PREACHINGS IN THIRUMANDIRAM]
Authors: R.VALLI
Published: October 2021

Thirumoolar has written Thirumandiram under 9 Tantras based on 9 agamas. (It is said that there were originally 28 agamas and only 9 were taught to Tirumular by his Guru) First 4 tantrams of Tirumandiram explains Aram, Porul, Inbham and Veedu (together known as Nan-marai - Tamil vedam) The other portion describe the way of worship, based on the agamas. It is enough if we remember that Agamas and Tamil vedas are known as Arumarai explaining the philosophy. Those explaining the way of worship and also praising that Supreme Power are Tirumurai. Tirumandiram is both Arumarai and Tirumurai. Herein an attempt has been made to understand the contents of a few of the verses of that great work: Pathy-Pasu-Pasam is the crux of Saivite philosophy. Pathy represents the Supreme, Pasu represents the Jeeva and Pasam represents ego, karmam and maya. Pathy is anadhy i.e. beginingless and also eternal. Pasu and Pasam have also no beginning but they have an end in the sense that ultimately, they become one with Pathy. Ego is the cause of birth. This study tries to attempt the Preaching of Thirumantra. Library research was done and explanatory method was adopted for this study. Findings of this study was having taken birth one should meditate Panchaksharam thereby he attains the stage of Sivayogi. "Chetthiruppar Sivayogiargal" - they are with the physical body, apparently dead. They (Sivayogiargal) outlive non-understanding and mis-understanding (avaranam and vikshepam) and ego (sense of I and mine) They are awake in the apparent sleep.
La Calzada México-Tacuba: retos en la regeneración y reactivación de un camino histórico
Authors: Hernández Septién Gerardo A.
Published: October 2021

La antigua Calzada México-Tacuba se encuentra en la Ciudad de México, capital del país al que dio nombre. Creada en un entorno lacustre en el siglo XIV, esta avenida de casi 10 km de longitud es considerada la vía más antigua del continente americano. Por ella han desfilado importantes acontecimientos de la historia nacional, de los cuales aún hay algunos testimonios tangibles. El presente artículo pretende hablar de la importancia histórica y urbana de la Calzada México-Tacuba, como una vía viva con un gran potencial como detonador del desarrollo urbano, cultural y turístico, pero que por desgracia ha visto mermada sus cualidades espaciales y valores tangibles e intangibles, a manos de la falta de regulación, y un entorno conflictivo y hostil en casi toda su trayectoria. El paisaje urbano histórico de la Calzada, unida a la dinámica de sus barrios aledaños, debe contar el día de hoy con políticas públicas y privadas que permeen a la sociedad en conjunto para que se de, de manera continuada y sostenible, su rescate y puesta en valor. Estos temas también se analizan en el presente artículo.
La Red Andaluza de Semillas, buenas prácticas en el mantenimiento sostenible del ecosistema agrario
Authors: Soriano Niebla Juan José
Published: October 2021

En sus más de 18 años de recorrido, la Red de Andaluza de semillas ha venido desarrollando y documentando una importante experiencia en la defensa, recuperación y utilización de la biodiversidad cultivada. Esta experiencia ha servido de base para reflexionar sobre la complejidad de este legado rural y las diferentes formas de nombrarlo y entenderlo: recursos genéticos, variedades tradicionales y locales, conocimiento campesino, memoria biocultural… En este extenso patrimonio, de naturaleza tanto cultural como natural, se encuentran claves para conciliar los objetivos de desarrollo con el uso sostenible de los recursos a escala local. Las visiones desarrolladas en los ámbitos de la agroecología y la soberanía alimentaria permiten interpretar esta sabiduría y contextualizarla para dar respuesta a retos actuales. Así han surgido estas buenas prácticas para el cultivo y la elaboración de alimentos, respetuosas con la protección del medio natural y basadas en la valorización del patrimonio genético agrícola.
Conocimientos locales y desarrollo sostenible en Perú. El proyecto SIPAM Agrosistemas de alta montaña
Authors: Pérez Galán Beatriz
Published: October 2021

En esta contribución se reflexiona sobre las bases sociales y culturales de los sistemas agrícolas tradicionales en el caso de los pueblos indígenas al sur de los andes peruanos. El ejemplo se extrae del proyecto piloto “agroecosistemas de alta montaña, de Machupicchu al lago Titicaca” integrado al programa SIPAM (FAO-GEF).

Desde una perspectiva antropológica crítica y con el énfasis puesto en la matriz cultural de las prácticas agrícolas tradicionales indígenas en este texto se analiza la concepción estática, reificada, homogénea, y esencialista que es atribuida en la práctica por el discurso conservacionista y del desarrollo sostenible a los conocimientos locales indígenas en este proyecto, lo que dificultaría en la práctica su conservación.
Valero Matas, J.A. Patrimonio cultural, sostenibilidad y desarrollo humano en lo rural
Authors: Quinto Fernández Silvia Isabel
Published: October 2021

Resumen del libro Patrimonio cultural, sostenibilidad y desarrollo humano en lo rural, de J.A. Valero Matas, editado por Tirant Lo Blanch.
Orthoptic Sets and Quadric Hypersurfaces
Authors: DUBEAU François
Published: October 2021

Orthoptic curves for the conics are well known.
It is the Monge's circle for ellipse and hyperbola, and for parabola it is its directrix.
These conics are level sets of quadratic functions in the plane.
We consider level sets of quadratic functions in higher dimension, known as quadric hypersurfaces.
For these hypersurfaces we present and study their orthoptic sets, which extend the idea of orthoptic curves for conics.
Phytoplankton of cold-water lake ecosystems under the influence of natural and anthropogenic factors
Authors: Sharov Andrey N.
Published: October 2021

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.
Global forestry: international and national strategic directions for sustainable spatial development
Authors: Mishenin Ye. , Yarova I. , Mishenina H. , Dutchenko O.
Published: October 2021

The article outlines the main strategic guidelines for sustainable spatial development of forest management at different hierarchical levels of forest management (global, national, regional and local), which are related to the formation of a sustainable forest management system on an ecosystem basis in accordance with international principles and agreements on sustainable forest development. Emphasis is placed on the formation of the system of international ecological management of forestry for the implementation of the ecosystem approach in the system of spatial forest management. The necessity of forming a fundamentally new state ecologically oriented forest policy of Ukraine, based on the reassessment of human views on the role of forests in the global environment, was stated. The basic requirements for ecologically oriented national forest policy in the field of rational use and reproduction and protection of forest resources are formed. The main ways of solving environmental problems in the system of sustainable forestry are also outlined. The main directions of long-term development of global forestry are determined. The main directions of long-term development of global forestry are determined. The main components of international regulation of relations between states in the field of compliance with environmental requirements in the field of forestry have been formed.
Influence of plant exometabolites of different soybean varieties on aggressiveness and intensity of sporulation of Fusarium graminearum Schwabe
Authors: Parfenuk A. , Havryliuk L. , Kosovska N. , Beznosko I. , Draga M.
Published: October 2021

The article presents the results of studies of the influence of exometabolites in plants of different soybean varieties and technologies of their cultivation on the aggressiveness and intensity of sporulation of fungi isolates Fusarium graminearum Schwabe.
The object of the study were plant exometabolites of soybean varieties: Suzirya of selection of National Research Center of the Institute of Agriculture of NAAS of Ukraine and Kent of selection of Saatbau Linz in Austria. Since organic production denies the use of mineral fertilizers and chemical plant protection products, an alternative to them is the use of technologies with biological products of different action. Therefore, of these varieties of soybean plants were grown according to the technologies developed in the companies: Filazonit Ukraine LLC, Modern Agricultural Technologies LLC, A-Rice LLC, as well as in the company BTU-Center, PE.
Found that exometabolites of studied soybean varieties, grown on listed technologies, lead to increased aggressiveness of isolates of the fungus F. graminearum. Thus, against the background of exometabolites of soybean plants of the Suzirya variety, the index of seedling damage ranged from 21.3% to 29.8%, and against the background of exometabolites of soybean plants of the Kent variety — from 21.14% to 25.46%. This indicates their medium aggressiveness and stabilizing selection in the fungus population.
It is established that the exometabolites of the studied soybean cultivars grown by the listed technologies lead to a decrease in the intensity of sporulation of fungus isolates F. graminearum compared to control. Thus, against the background of exometabolites of soybean plants of the Suzirya variety, the index of seedling damage ranged from 5,7·106 cells/ml to 12,11·106 cells/ml, and against the background of exometabolites of soybean plants of the Kent variety — from 4,25·106 cells/ml to 10,2·106 cells/ml. This indicates their average aggressiveness and stabilizing selection in the population of the fungus on this basis.
Thus, the obtained results of studies point to a significant influence of metabolic products of plants of different varieties of soybean and their cultivation technology on physiological and biochemical properties of pathogenic fungi F. graminearum.
Raspberry plant mycobiom under the influence of complex organic-mineral fertilizer viteri in the Central Forest Steppe of Ukraine
Authors: Mineralova V. , Parfenuk A. , Beznosko I.
Published: October 2021

The results of research on the influence of foliar treatment of raspberry plants with organic fertilizer VITERI on the population size and species composition of micromycetes in the mycobiome of the rhizosphere and vegetative organs of raspberry plants of Joan J in the Central Forest-Steppe of Ukraine are presented. Microbiological, phytopathological, mycological methods and methods of sampling of raspberry plants during the growing season were used for the study. To determine the effect of VITERI fertilizer on the mycobiota of the rhizosphere and vegetative organs of raspberry plants during plant ontogeny, additional foliar treatment was performed with 1% aqueous solution of VITERI fertilizer. It was found that the population is dominated by fungi of following species: Septoria rubi, West, Aspergillus niger,  V. Tiegh, Alternaria alternata, (Fr.) Keissl, Fusarium spp. These micromycetes are producers of mycotoxins and can cause disease in animals and humans, as well as contribute to biological contamination of agroecosystems. During foliar treatment of raspberry plants with VITERI fertilizer, a significant decrease in phytopathogenic load was observed in the phase of intensive fruiting compared to other phases of ontogenesis of raspberry plants.
USING MINI-PROJECTS IN THE STUDY OF MATHEMATICAL ANALYSIS
Authors: Zakharova Tatyana E.
Published: October 2021

The article considers such type of independent work of students as mini-projects. This activity, due to an active and creative approach, allows students to get interested in studying the material. As a result, the understanding of topics increases, and the training becomes more efficient. Examples of tasks for mini-projects on some topics of mathematical analysis are given.
USING OF I-EXAM.RU INFORMATION PORTAL FOR TEACHING MATHEMATICAL DISCIPLINES
Authors: Krylova Elena M. , Neklyudova Vera L.
Published: October 2021

The paper considers the possibilities of the information portal i-exam.ru, used to organize teaching Mathematics and other disciplines, including activities that can be carried out with computer testing.
FORMATIVE ASSESSMENT OF STUDENTS IN CONDITIONS OF DISTANCE LEARNING
Authors: Shmigirilova Irina B. , Kopnova Oskana L.
Published: October 2021

The article actualizes the importance of formative assessment in professional training of future mathematics teachers in context of distance learning. Experience of distance learning technology to improve assessment interaction efficiency is summarized.
IMPLEMENTATION ASPECTS OF THE PROJECT-BASED METHOD IN THE PROCESS OF TEACHING FOREIGN LANGUAGES AT A TECHNICAL UNIVERSITY
Authors: Zhdanov Sergey S.
Published: October 2021

The paper deals with tasks and features of using the project-based method in the educational process at the university in general as well as in the frameworks of teaching foreign languages. The author points out advantages of this method and certain challenges that a teacher may face while implementing it. Some practical variants of using the project-based method are also analyzed in application to teaching foreign languages.
A STRUCTURAL MODEL DESCRIBING THE PROJECT PROBLEM: INTRODUCTION EXPERIENCE
Authors: Nizovkina Natalia G.
Published: October 2021

The annual experience of using the McKinsey model is given. Students selected business cases or virtual projects in the "Project Management" course. They used the structural description of the problem. In this paper, the main theme of cases and projects are presented. The depths of problems study as the average number of levels of the Minto pyramid are assessed. The main issue we study is the feedback of students about the approach of the consulting firm McKinsey.
MODERN TECHNOLOGIES FOR TEACHING GEOMETRY IN CONDITIONS OF DISTANCE LEARNING
Authors: Abramova Olesya M.
Published: October 2021

The article is devoted to the use of web quests in geometry lessons, the possibilities of introducing this educational technology into educational process are revealed in order to improve quality of educational services. The advantages of using web quests in educational process are considered. An example of a geometry web quest for grade 7 students is provided.
SEACHER AND ANALYSIS IN OLYMPIAD PROBLEMS. EVALUATION CRITERIA
Authors: Vakhromeev Yury M. , Vakhromeeva Tatyana V.
Published: October 2021

Olympiad problems that can be solved both by long monotonous calculations, following a given algorithm, and analytically are analyzed. The possibility of using such tasks in intra-university Olympiads of technical universities is justified.
DEVICE FOR CREATING SLOTS-VOLTAGE CONCENTRATORS IN THE BOUNDARY AREA OF WELLS IN FINE ROCKS
Authors: Leont’ev Arkady V. , Rubtsova Ekaterina V.
Published: October 2021

It is shown that in order to expand the field of practical application of directional measuring hydraulic fracturing, it is necessary to create technical means that provide cutting of initiating slots on the walls of boreholes in rock masses of different strength. A new slotter design is proposed, the distinctive feature of which is using carbide cutters that are extended during cutting slots along the normal to the device axis. The device is brought into operation due to its normalized movement tagging the bottom. The slotter dimensions allow using it in diamond drill holes of 76 mm diameter. The device is designed to create stress concentrator slots in adjoining zones of boreholes in hard rocks with a coefficient of 5-8 according to M. M. Protodyakonov’s scale.
WAYS TO INCREASE THE EFFICIENCY OF ENGINEERING PROCESSES WHEN FORMING HIGH-DENSITY ARRAYS OF DISPERSE MATERIALS
Authors: Morozov Alexey V. , Levenson Samuil Y.
Published: October 2021

One of the most important production operations in open pit mining is dumping. The depth of open pit mines increases constantly and the volume of overburden rocks also grows. Overburden is truck-delivered to the dumps. Fractional composition of overburden is diverse. In the early years, loose rocks were transported to the dumps from the upper horizons to the lower levels of the dumps, and in subsequent years - hard rocks. In this view, due to the low strength and stability of the dump mass, it is usually not possible to provide safe working conditions. The mining safety can be increased due to the compaction of rocks composing the dump mass. Based on the analysis of technologies for compaction of dispersed materials using known equipment, a self-propelled vibration device is proposed for the formation of a stable dump mass. The use of a vibrating function element in the design, which implements a polyharmonic vibration mode, will expand the scope of its application during the open pit mining.
EXPERIMENTAL DETERMINATION OF STRESS PARAMETERS IN THE MINING FIELD
Authors: Skulkin Alexander A.
Published: October 2021

The experience of measuring the stress state of the rock mass at the Tashtagol iron ore deposit and the result of stresses acting in the induced field in the vicinity of 10 orts at a depth of 800 m from the daily surface (horizon -350) is presented using the method of measuring hydraulic fracturing. Stress concentration zones around the mine are determined at the measuring station.
NUMERICAL SIMULATION OF THE BROKEN ROCK MASS TRANSPORTATION IN A ROTATING PIPELINE
Authors: Khan Guil Nam , Rusin Evgeny P.
Published: October 2021

The impact of the angular velocity of a horizontal pipe rotating around its longitudinal axis and the shape of its cross-section on the efficiency of pneumatic conveying of bulk material in it has been numerically investigated by the discrete elements method. The maximum number of non-contact particles, that is, particles being not in contact with other material particles and with the pipe, in the cross section of the pipe during one its revolution, is assumed the condition for effective pneumatic conveying. A method for searching for non-contact particles is proposed, which makes it possible to calculate their number at fixed pipe position angles during its rotation. For various cross-sectional shapes, the optimal angular velocities are determined at which the average number of non-contact particles in the cross-section is maximum. The results of the study can be used to increase the productivity of the removal of products of destruction when drilling horizontal boreholes in rocks and soils.
EXPERIENCE OF STEEL PILE DRIVING BY PNEUMATIC HAMMERS IN UNDERGROUND CONSTRUCTION BY THE CUT-AND-COVER METHOD
Authors: Chervov Vladimir V.
Published: October 2021

The timeliness of application of pneumatic hammers in the deep bore tunneling in underground construction is justified. The penetration resistance forces in steel pipe driving in soil are determined. The analysis of long-term operation of adjustable capacity pneumatic hammers shows the conformity of the blow energy and the driven pipe diameter. The relationship between the unit blow energy and the open-ended pipe diameter is proposed. The main pneumatic hammer parameter to govern the machine performance is substantiated. The standard pneumatic hammers of adjustable capacity are characterized. The cases of vertical pipe driving at construction sites in Russia are described. The technological capability of construction of retention wall in soil using rolled steel, namely, I-beams, U-sections, piling bars, etc. is illustrated. The production tooling arrangements to ensure secure mounting of the hammer on the axial element driven in soil are described.
EXTRACTION OF OPEN PIT BOTTOM RESERVES BY ROOM-AND-PILLAR METHOD USING HYBRID BACKFILL
Authors: Shchukin Sergei A. , Neverov Aleksandr A. , Neverov Sergei A.
Published: October 2021

For the transition from open pit to underground mining in thin and steeply dipping ore bodies, it is proposed to use the room-and-pillar method with hybrid backfill. The geotechnology assumes bottom-up mining within levels which are generally sequenced top downward. The hybrid backfill is waste rock and rubble concrete. The authors discuss the multivariate problem on the stability of structural elements of the geotechnology with ranking of basic parameters in the field of natural tectonic stresses. The geotechnology safety is proved by the 3D FEM-based stress-strain analysis of the limiting case of mine roof spans. The stress patterns in the structural elements of the technology are determined, and the areas of instability are identified. The rubble concrete pillars effectively ensure mining safety with the discussed technology. The hybrid backfill as against rock fill is a more reliable method of ground control, especially in case of increasing thickness of ore bodies.
COMPARISON OF THE EFFICIENCY OF OIL AND GAS COMPANIES USING THE DEA METHOD
Authors: Ade Elizaveta V. , Filimonova Irina V.
Published: October 2021

The article presents the DEA method. This method is used to assess the efficiency of socio-economic systems. The features of its application for oil and gas companies are considered. The advantages and disadvantages of this method are described. The features of selecting the model parameters are described.
INNOVATIVE AND RESOURCE FACTORS OF DEVELOPMENT IN RUSSIAN REGIONS
Authors: Novikov Alexander Yu.
Published: October 2021

The innovation and resource factor of economic development has been studied actively, since the middle of the 20th century. The problem of taking into account the innovative factor in regression analysis is urgent now. Several empirical indicators correspond to the innovation factor, but they cannot fully reflect the meaning of innovation used in theoretical models. There is a need to choose the indicator that would least distort the essence of the scientific and technical progress. We use panel regressions and data about Russian regions for 2014-2018. . It was shown, that that the resource factor has a positive effect on economic growth, and the innovation factor is insignificant.
RESEARCH OF TARIFF FORMATION FOR PIPELINE DELIVERIES OF RUSSIAN OIL
Authors: Pershina Alina Ol. , Zemnukhova Ekaterina А.
Published: October 2021

An adequate and balanced choice of a model for regulating tariffs for the supply of hydrocarbons through pipelines has a decisive impact on the level of costs of participants in the transportation process, and the profits of economic entities. The classification of methods for determining tariffs for oil transportation, the specifics of the formation of tariffs in the United States and Russia, as well as a comparative analysis of the cost of transportation by various modes of transport for these countries are presented. The choice in the work of the American and Russian markets is due to the fact that the US oil transportation infrastructure is the closest in terms of the scale of development of the oil industry, as well as the degree of development of the pipeline system to the Russian Federation.
MECHANISMS AND DIRECTIONS FOR INCREASING THE LEVEL OF INNOVATIVE DEVELOPMENT OF THE OIL AND GAS COMPLEX OF RUSSIA
Authors: Filimonova Irina V.
Published: October 2021

The article describes one of the important directions of increasing the level of innovative development of the oil and gas complex of Russia - the development of hard-to-recover hydrocarbon reserves (HTR). The search, exploration and development of hard-to-recover reserves can bring the domestic oil and gas and related industries to a new level of technological development, provide a significant multiplier effect for related industries, and create new jobs and infrastructure. The authors estimated the share of HTR in modern oil production, analyzed the dynamics and structure of hydrocarbons of special quality and conditions.
NUMERICAL AND EXPERIMENTAL MODELING OF PROPAGATION OF LONGITUDINAL FRACTURES IN MULTI-STAGE HYDRAULIC FRACTURING WITH VISCOUS FLUID
Authors: Panov Anton V. , Kolykhalov Igor V.
Published: October 2021

The experimental and numerical modeling of curvilinear propagation of hydraulic fractures driven by viscous fluid is implemented. The trajectories of simultaneous growth of 2-5 fractures from the boundary of a circular opening are presented in plane elasticity. The influence of the fluid viscosity on the fracture trajectory is analyzes. The causes of initiation of main fracture and shut-down of other fractures are revealed. The attempts are made to find such conditions that simultaneous growth of a few main fractures is possible by varying lengths and orientation angles of initiation fractures in the external nonuniform field of compression. The experimental modeling of hydraulic fractures was carried out using blocks made of concrete and organic glass. There were 3 to 5 initiation fractures. The influence of the breakdown fluid viscosity on the number of the main fractures is illustrated. Hydraulic fracturing with a plastic material allowed simultaneous growth of 3 and 4 fractures within a block. The experimental modeling data and the calculation results are compared.
REDUCTION IN WEIGHT OF HOUSING OF AXIAL MINE FAN IMPELLER WITH ROTATING BLADES
Authors: Panova Nadezhda V.
Published: October 2021

The study uses topological optimization techniques in design of the housing of an impeller meant for the increased rotational speeds in ANSYS. The objective function of the impeller optimization is the minimum yield, and the optimization parameter is assumed as the change in the interior volume of the structure under certain constraints imposed on the external geometry of the impeller. The optimization of the impeller housing shows that it is possible to reduce the weight of the power belt, and to make one web to be load-bearing and the other web to be thinner, or to switch to the impeller with one web. Moreover, the design can use some elements of a lattice structure.
DEVELOPMENT OF A TEST BENCH FOR SIMULATION OF ELEMENTS OF GRANULAR MATERIAL PROCESSING SYSTEMS
Authors: Rusin Evgeny P.
Published: October 2021

The paper deals with the development of an original laboratory test bench for modeling elements of granular material processing systems. The core of the test bench is a modified abrasive blasting machine. In this version of the test bench, a changeable module in the form of a flat curved channel imitates an elbow of a pneumatic conveying system. The test bench will allow studying the erosive wear of such elbows.
Cascades of Periodic Solutions in a Neural Circuit With Delays and Slow-Fast Dynamics
Authors: Ferrario Andrea , Rankin James
Published: October 2021

We analyse periodic solutions in a system of four delayed differential equations forced by periodic inputs representing two competing neural populations connected with fast mutual excitation and slow delayed inhibition. The combination of mechanisms generates a rich dynamical structure that we are able to characterize using slow-fast dissection and a binary classification of states. We previously proved the existence conditions of all possible states 1:1 locked to the inputs and applied this analysis to the tracking of the rhythms perceived when listening to alternating sequences of low and high tones. Here we extend this analysis using analytical and computational tools by proving the existence a set of n:1 periodically locked states and their location in parameter space. Firstly we examine cycle skipping states and find that they accumulate in an infinite cascade of period-incrementing bifurcations with increasing periods for decreasing values of the local input strength. Secondly we analyse periodic solutions that alternate between 1:1 locked states that repeat after an integer multiple of the input period (swapping states). We show that such states accumulate in similar bifurcation cascades with decreasing values of the lateral input strength. We report a parameter-dependent scaling constant for the ratio of widths of successive regions in the cascades, which generalises across cycle skipping and swapping states. The periodic states reported here - emergent behaviours in the model - can be linked to known phenomena in auditory perception that are beyond the original scope of the model’s design.
Coaxially Bioprinted Cell-Laden Tubular-Like Structure for Studying Glioma Angiogenesis
Authors: Wang Xuanzhi , Li Xinda , Zhang Yi , Long Xiaoyan , Zhang Haitao , Xu Tao , Niu Chaoshi
Published: October 2021

Glioblastomas are the most frequently diagnosed and one of the most lethal primary brain tumors, and one of their key features is a dysplastic vascular network. However, because the origin of the tumor blood vessels remains controversial, an optimal preclinical tumor model must be established to elucidate the tumor angiogenesis mechanism, especially the role of tumor cells themselves in angiogenesis. Therefore, shell-glioma cell (U118)-red fluorescent protein (RFP)/core-human umbilical vein endothelial cell (HUVEC)-green fluorescent protein (GFP) hydrogel microfibers were coaxially bioprinted. U118–RFP and HUVEC–GFP cells both exhibited good proliferation in a three-dimensional (3D) microenvironment. The secretability of both vascular endothelial growth factor A and basic fibroblast growth factor was remarkably enhanced when both types of cells were cocultured in 3D models. Moreover, U118 cells promoted the vascularization of the surrounding HUVECs by secreting vascular growth factors. More importantly, U118–HUVEC-fused cells were found in U118–RFP/HUVEC–GFP hydrogel microfibers. Most importantly, our results indicated that U118 cells can not only recruit the blood vessels of the surrounding host but also directly transdifferentiate into or fuse with endothelial cells to participate in tumor angiogenesis in vivo. The coaxially bioprinted U118–RFP/HUVEC–GFP hydrogel microfiber is a model suitable for mimicking the glioma microenvironment and for investigating tumor angiogenesis.
Regulating Water Reduction Kinetics on MoP Electrocatalysts Through Se Doping for Accelerated Alkaline Hydrogen Production
Authors: Liu Zhenpeng , Bu Jun , Ma Wenxiu , Yang Bin , Zhang Lei , Zhong Hong , Li Shuangming , Zhang Jian
Published: October 2021

Owing to its low cost, high conductivity, and chemical stability, Molybdenum phosphide (MoP) has great potential for electrochemically catalyzing the hydrogen evolution reaction (HER). Unfortunately, the development of high-activity MoP still remains a grand challenge in alkali-electrolyzers due to its sluggish water reduction kinetics. Here, we demonstrate a novel strategy for regulating the HER kinetics of the MoP nanowire cathode through partially substituting P atoms with Se dopants. In alkaline solutions, the Se-doped MoP (Se-MoP) nanowire cathode exhibits excellent HER performance with a greatly-decreased overpotential of ∼61 mV at 10 mA cm−2 and a Tafel slope of ∼63 mV dec−1, outperforming currently reported MoP-based electrocatalysts. Experimental and theoretical investigations reveal that Se doping not only facilitates the water dissociation on MoP, but also optimize the hydrogen adsorption free energy, eventually speeding up the sluggish alkaline HER kinetics. Therefore, this work paves a new path for designing MoP-based electrocatalyst with high HER performance in alkaline electrolyzers.
Machine Learning of Serum Metabolic Patterns Encodes Asymptomatic SARS-CoV-2 Infection
Authors: Wan Qiongqiong , Chen Moran , Zhang Zheng , Yuan Yu , Wang Hao , Hao Yanhong , Nie Wenjing , Wu Liang , Chen Suming
Published: October 2021

Asymptomatic COVID-19 has become one of the biggest challenges for controlling the spread of the SARS-CoV-2. Diagnosis of asymptomatic COVID-19 mainly depends on quantitative reverse transcription PCR (qRT-PCR), which is typically time-consuming and requires expensive reagents. The application is limited in countries that lack sufficient resources to handle large-scale assay during the COVID-19 outbreak. Here, we demonstrated a new approach to detect the asymptomatic SARS-CoV-2 infection using serum metabolic patterns combined with ensemble learning. The direct patterns of metabolites and lipids were extracted by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) within 1 s with simple sample preparation. A new ensemble learning model was developed using stacking strategy with a new voting algorithm. This approach was validated in a large cohort of 274 samples (92 asymptomatic COVID-19 and 182 healthy control), and provided the high accuracy of 93.4%, with only 5% false negative and 7% false positive rates. We also identified a biomarker panel of ten metabolites and lipids, as well as the altered metabolic pathways during asymptomatic SARS-CoV-2 Infection. The proposed rapid and low-cost approach holds promise to apply in the large-scale asymptomatic COVID-19 screening.
Association Between Subconjunctival Hemorrhage and Acute Coronary Syndrome: A 14-Year Nationwide Population-Based Cohort Study
Authors: Chiang Ping-Hao , Lai Jung-Nien , Chiang Yun-Chi , Hu Kai-Chieh , Hsu Min-Yen , Wei James Cheng-Chung
Published: October 2021

Purpose: Subconjunctival hemorrhage (SCH) is usually a benign ocular disorder that causes painless, redness under the conjunctiva. However, since SCH and acute coronary syndrome (ACS) share many vascular risk factors, studies have suggested that these two disorders may be significantly associated with each other, and evaluate the concomitance of ACS in patients with SCH.

Methods: This population-based cohort study, enrolled 35,260 Taiwanese patients, and used the Taiwan National Health Insurance Research Database to identify patients with ACS and SCH. Outcomes were compared between the with and without SCH groups. The study population was followed until the date of ACS onset, the date of withdrawal, death, or December 31st 2013, whichever came first.

Results: Of the 85,925 patients identified with SCH between 1996 and 2013, 68,295 were excluded based on the study's exclusion criteria, and a total of 17,630 patients with SCH who were diagnosed by ophthalmologists between 2000 and 2012 were eligible for analysis. After 1:1 propensity score matching for 5-year age groups, gender, and the index year, the results showed that SCH was more common in the 40–59 age group (53.82%) and females (58.66%). As for the ACS-related risk factors, patients with diabetes mellitus (aHR = 1.58, 95% CI = [1.38, 1.81]), hypertension (aHR = 1.71, 95% CI = [1.49, 1.96]) and patients taking aspirin (aHR = 1.67, 95% CI = [1.47, 1.90]) had a notably higher risk of ACS. However, it was found that there were no significant differences in the occurrence of ACS between the non-SCH and SCH patients.

Conclusion: This results of this study regarding the risk factors and epidemiology of SCH and ACS were in keeping with previously reported findings. However, the results revealed no significant association between SCH and ACS.
Organ Culture Model of Aortic Valve Calcification
Authors: Chester Adrian H. , Sarathchandra Padmini , McCormack Ann , Yacoub Magdi H.
Published: October 2021

A significant amount of knowledge has been gained with the use of cell-based assays to elucidate the mechanisms that mediate heart valve calcification. However, cells used in these studies lack their association with the extra-cellular matrix or the influence of other cellular components of valve leaflets. We have developed a model of calcification using intact porcine valve leaflets, that relies upon a biological stimulus to drive the formation of calcified nodules within the valve leaflets. Alizarin Red positive regions were formed in response to lipopolysaccharide and inorganic phosphate, which could be quantified when viewed under polarized light. Point analysis and elemental mapping analysis of electron microscope images confirmed the presence of nodules containing calcium and phosphorus. Immunohistochemical staining showed that the development of these calcified regions corresponded with the expression of RUNX2, osteocalcin, NF-kB and the apoptosis marker caspase 3. The formation of calcified nodules and the expression of bone markers were both inhibited by adenosine in a concentration-dependent manner, illustrating that the model is amenable to pharmacological manipulation. This organ culture model offers an increased level of tissue complexity in which to study the mechanisms that are involved in heart valve calcification.
Collecting Microplastics in Gardens: Case Study (i) of Soil
Authors: Sobhani Zahra , Luo Yunlong , Gibson Christopher T. , Tang Youhong , Naidu Ravi , Megharaj Mallavarapu , Fang Cheng
Published: October 2021

As an emerging contaminant, microplastic is receiving increasing attention. However, the contamination source is not fully known, and new sources are still being identified. Herewith, we report that microplastics can be found in our gardens, either due to the wrongdoing of leaving plastic bubble wraps to be mixed with mulches or due to the use of plastic landscape fabrics in the mulch bed. In the beginning, they were of large sizes, such as > 5 mm. However, after 7 years in the garden, owing to natural degradation, weathering, or abrasion, microplastics are released. We categorize the plastic fragments into different groups, 5 mm–0.75 mm, 0.75 mm–100 μm, and 100–0.8 μm, using filters such as kitchenware, meaning we can collect microplastics in our gardens by ourselves. We then characterized the plastics using Raman image mapping and a logic-based algorithm to increase the signal-to-noise ratio and the image certainty. This is because the signal-to-noise ratio from a single Raman spectrum, or even from an individual peak, is significantly less than that from a spectrum matrix of Raman mapping (such as 1 vs. 50 × 50) that contains 2,500 spectra, from the statistical point of view. From the 10 g soil we sampled, we could detect the microplastics, including large (5 mm–100 μm) fragments and small (<100 μm) ones, suggesting the degradation fate of plastics in the gardens. Overall, these results warn us that we must be careful when we do gardening, including selection of plastic items for gardens.
Insect and Disease Disturbances Correlate With Reduced Carbon Sequestration in Forests of the Contiguous United States
Authors: Quirion Brendan R. , Domke Grant M. , Walters Brian F. , Lovett Gary M. , Fargione Joseph E. , Greenwood Leigh , Serbesoff-King Kristina , Randall John M. , Fei Songlin
Published: October 2021

Major efforts are underway to harness the carbon sequestration capacity of forests to combat global climate change. However, tree damage and death associated with insect and disease disturbance can reduce this carbon sequestration capacity. We quantified average annual changes in live tree carbon accumulation associated with insect and disease disturbances utilizing the most recent (2001 – 2019) remeasurement data from National Forest Inventory plots in the contiguous United States. Forest plots recently impacted by insect disturbance sequestered on average 69% less carbon in live trees than plots with no recent disturbance, and plots recently impacted by disease disturbance sequestered on average 28% less carbon in live trees than plots with no recent disturbance. Nationally, we estimate that carbon sequestration by live trees, defined as the estimated average annual rate of above- and belowground carbon accumulation in live trees (diameter at breast height ≥ 2.54 cm) on forest land, has been reduced by 9.33 teragrams carbon per year (95% confidence interval: 7.11 to 11.58) in forests that have experienced recent insect disturbance and 3.49 teragrams carbon per year (95% confidence interval: 1.30 to 5.70) in forests that have experienced recent disease disturbance, for a total reduction of 12.83 teragrams carbon per year (95% confidence interval: 8.41 to 17.28). Strengthened international trade policies and phytosanitary standards as well as improved forest management have the potential to protect forests and their natural capacity to contribute to climate change mitigation.
Integrating Sexual and Reproductive Health Services Within HIV Services: WHO Guidance
Authors: Ford Nathan , Newman Morkor , Malumo Sarai , Chitembo Lastone , Gaffield Mary E.
Published: October 2021

Among the 1.9 billion women of reproductive age worldwide in 2019, 1.1 billion need family planning and 270 million have an unmet need for contraception. For women and adolescent girls living with human immunodeficiency virus (HIV), using effective contraception reduces the mother-to-child transmission of HIV by preventing unintended pregnancies and enabling the planning and safer conception of desired pregnancies with optimal maternal and child health outcomes. The World Health Organization (WHO) recommends that sexual and reproductive health services, including contraception, may be integrated within HIV services. Integration is associated with increased offers and uptake of sexual and reproductive health services, including contraception, which is likely to result in improved downstream clinical outcomes. Integrating HIV and sexual and reproductive health services has been found to improve access, the quality of antenatal care and nurse productivity while reducing stigma and without compromising uptake of care. Research is encouraged to identify approaches to integration that lead to better uptake of sexual and reproductive health services, including contraception. Implementation research is encouraged to evaluate different strategies of integration in different health systems and social contexts; such research should include providing contraception, including long-acting contraception, in the context of less frequent clinical and ART refill visits.
Development and Validation of a Combined Glycolysis and Immune Prognostic Model for Melanoma
Authors: Yang Yang , Li Yaling , Qi Ruiqun , Zhang Lan
Published: October 2021

Background

Glycolytic effects and immune microenvironments play important roles in the development of melanoma. However, reliable biomarkers for prognostic prediction of melanoma as based on glycolysis and immune status remain to be identified.

Methods

Glycolysis-related genes (GRGs) were obtained from the Molecular Signatures database and immune-related genes (IRGs) were downloaded from the ImmPort dataset. Prognostic GRGs and IRGs in the TCGA (The Cancer Genome Atlas) and GSE65904 datasets were identified. Least absolute shrinkage and selection operator (LASSO) Cox regression and multivariate Cox regression were used for model construction. Glycolysis expression profiles and the infiltration of immune cells were analyzed and compared. Finally, in vitro experiments were performed to assess the expression and function of these CIGI genes.

Results

Four prognostic glycolysis- and immune-related signatures (SEMA4D, IFITM1, KIF20A and GPR87) were identified for use in constructing a comprehensive glycolysis and immune (CIGI) model. CIGI proved to be a stable, predictive method as determined from different datasets and subgroups of patients and served as an independent prognostic factor for melanoma patients. In addition, patients in the high-CIGI group showed increased levels of glycolytic gene expressions and exhibited immune-suppressive features. Finally, SEMA4D and IFITM1 may function as tumor suppressor genes, while KIF20A and GPR87 may function as oncogenes in melanoma as revealed from results of in vitro experiments.

Conclusion

In this report we present our findings on the development and validation of a novel prognostic classifier for use in patients with melanoma as based on glycolysis and immune expression profiles.