bluuebunny/crossref_metadata_2025 huggingface dataset:
Arcobriga, Segontia Lanca, Ocilis y Cortona. En torno a los nombres indígenas de tres oppida celtibéricos
Authors: Bartolomé Bellón Gabriel
Published: July 2021

La identificación de los nombres de los oppida del final de la Edad del Hierro ha despertado el interés de los historiadores y arqueólogos desde la Plena Edad Media. A lo largo de los siglos, especialmente en los últimos doscientos años, han sido numerosas las propuestas por ubicar en localidades y yacimientos concretos los topónimos de ciudades prerromanas y romanas citadas por las fuentes griegas y romanas y por los documentos epigráficos. En este artículo abordamos los casos de tres yacimientos de la provincia de Soria que se han vinculado con diferentes oppida celtibéricos y ciudades romanas, sin tener, en ocasiones, los suficientes argumentos para ello: Medinaceli, identificado tradicionalmente con Ocilis y, en las últimas décadas, también con Cortona y Segontia; las Ruinas Ciclópeas de Santa María de Huerta y Granja de San Pedro, donde se ha situado la Arcobriga prerromana; Las Quintanas-La Cuesta del Moro de Langa de Duero vinculado, desde su descubrimiento y excavación por Blas de Taracena, con Segontia Lanca.
Análisis morfológico y contextual de las pinturas rupestres antropomorfas de la isla de Gran Canaria
Authors: Sosa-Alonso Pedro J.
Published: July 2021

En el presente trabajo mostramos una reflexión y análisis de las pinturas rupestres de figuras antropomorfas realizadas en las estaciones rupestres de Gran Canaria. Estos motivos representados en la roca se distribuyen en tres yacimientos arqueológicos de la isla: Majada Alta, Cuevas de Cubas y Cueva del Moro; espacios en los que hemos trabajado con técnicas de documentación no invasivas que nos han ayudado a conseguir los primeros calcos digitales de los pigmentos que se conservan en sus soportes. Este estudio ha sido necesario para conocer la verdadera morfología de los pigmentos conservados, lo que nos ha ayudado a comprender que los antropomorfos de cada yacimiento son diferentes entre sí, que no existe un estilo y que cada estación de pinturas se encuentra en un contexto diferente. Se trata de datos interesantes, pues reflejan la complejidad a la que nos enfrentamos a la hora de realizar vínculos entre las diferentes figuras humanas representadas, cuyo significado, cronologías y motivaciones no tienen por qué ser las mismas.
El singular conjunto de tituli picti del pecio de Ses Fontanelles (Mallorca, islas Baleares) y su contribución a la epigrafía anfórica tardorromana hispánica
Authors: Soler i Nicolau Antònia , Font Jaume Alexandre , Berni Millet Piero , García Riaza Enrique , Bernal-Casasola Darío , Cau Ontiveros Miguel Ángel , Cardell Perelló Jaume , Munar Llabrés Sebastià
Published: July 2021

En verano de 2019 fue descubierto en Ses Fontanelles (suroeste de Mallorca) un pecio romano con un cargamento de ánforas. Una excavación de urgencia ha sacado a la luz aproximadamente un tercio de los materiales, que están siendo estudiados. Este artículo se centra en las inscripciones (tituli picti) que presentan las ánforas (mayoritariamente Almagro 51C), un hallazgo excepcional dado su elevado número, además de por el tipo de escritura. Analizamos y relacionamos la paleografía con otros rótulos anfóricos en particular y documentos epigráficos en general; asimismo asociamos los tituli con el contenido de los envases a nivel arqueológico y aproximamos un estudio prosopográfico de los antropónimos que aparecen en dichos tituli. Finalmente, ponemos en relación los datos del cargamento con los de otros pecios imperiales. Al ser cuantitativamente el corpus de epigrafía anfórica pintada más importante de Hispania, el pecio se revela como una pieza clave para poder comprender con mayor nitidez la historia socioeconómica del siglo iv d. C.
Bamboo hybrid laminate board (Gigantochloa apus) strip with falcata veneer (Paraserianthes falcataria) in selected fiber directions
Authors: Sumardi Ihak , Dungani Rudi , Sulastiningsih Ignasia Maria , Aulia Deaul
Published: July 2021

This study investigated the physical and mechanical properties of bamboo hybrid laminate boards (BHLB) in various fiber directions as a potential wood-replacement structural material. This study used dry bamboo (Gigantochloa apus) processed into thin strips with a thickness of 4 mm and falcata veneer (Paraserianthes falcataria). The BHLB were arranged based on different fiber directions (i.e., perpendicular and parallel) in cold pressing (30 min; 22.2 kgf/cm2) and hot pressing (6 min; 15 kg/cm2). The adhesive used was urea-formaldehyde (UF) resin (glue spread rate of 250 g/m2 and inter veneer 170 g/m2). Physical and mechanical properties were observed to validate the feasibility of preparing BHLB from bamboo strips and falcata veneers. The results showed that the arrangement of the fiber direction affects dimensional stability, MOE (modulus of elasticity), MOR (modulus of rupture), shear strength, and screw withdrawal strength. Falcata veneer as the board core material resulted in lower density, low dimensional stability, and higher water absorption. However, the mechanical properties were not much different and fulfilled the standard for structural use. This study concludes that bamboo can be used for making composite BHLB as an alternative to wood-based composites for structural use.
Thickness accuracy of sash gang sawing
Authors: Orlowski Kazimierz A. , Sandak Jakub , Chuchala Daniel
Published: July 2021

Thin lamellae, corresponding to the layer components of structural glued members, i.e. 2-ply or 3-ply glued parquet, can be manufactured in re-sawing operations of kiln-dried wood blocks. These must be prepared with high dimensional accuracy and adequate surface quality following specific technical requirements for lamellae thickness variations, especially in the upper layers of the glued composite parquet. The accuracy of oak lamellae thickness was examined here for a re-sawing process performed on the sash gang saw. A series of cutting tests were carried out in sawmill production conditions. The overall objective for these observations was to determine an effect of both the cumulative time of sawing (progress of the tool wear) and the lamella position (distribution of lateral forces) on the dimensional accuracy of production. Lamellae size control was conducted following the Brown methodology. Detailed within-board, between-board, and total sawing standard deviations for the examined lamellae positions in the gang were determined. The obtained results revealed that outermost lamellae are more subjected to dimensional inaccuracy than lamellae from the centre of the sawn block or frieze.
Viršutinės virškinimo trakto dalies poepitelinių darinių endoskopinių, endoskopinių ultragarsinių ir giliosios biopsijos diagnostinių kriterijų nustatymo tyrimas
Authors:   , Vaicekauskas Rolandas
Published: July 2021

Evaluation of upper endoscopy, endoscopic ultrasound and deep biopsy diagnostic criteria of subepithelial upper gastrointestinal tract lesions
Lecturas intervalares de los términos numéricos en distintos contextos lingüísticos: un estudio experimental
Authors: Villaseñor García Gala , Curcó Carmen , Peralta Estrada María Teresa
Published: July 2021

Los términos numéricos en el uso lingüístico no siempre reciben una interpretación exacta. A veces los hablantes de la lengua hacen lecturas intervalares como al menos o cuando mucho. Por ello este fenómeno ha capturado la atención de diversos estudiosos y ha generado un gran debate tanto a nivel teórico como empírico (Horn, 1972, Geurts, 2006; Carston, 2004). La investigación que aquí se presenta tuvo como objetivo estudiar experimentalmente el nivel de aceptación de lecturas intervalares cuando el término numérico es antecedido por un artículo definido, cuando tiene función semántica de predicado o cuantificador, y cuando se encuentra bajo el alcance de algún operador modal epistémico o deóntico. Los resultados sugieren que en ausencia de un contexto pragmático que sesgue hacia las interpretaciones intervalares, éstas tienen un bajo nivel de aceptación. Sin embargo, en contextos modales epistémicos y deónticos débiles sí existe una aceptación de las lecturas acotadas superiormente.
Las limitaciones de Scopus como fuente de indicadores: Buscando una visibilidad integral para revistas argentinas en ciencias sociales
Authors: Rozemblum Cecilia , Alperin Juan Pablo , Unzurrunzaga Carolina
Published: July 2021

En este trabajo se avanza en la definición de un conjunto de indicadores para medir la visibilidad de las revistas científicas de ciencias sociales de manera integral. Para esto, se considera el uso de fuentes diversas que permitan conocer la citación, la accesibilidad y los alcances de las publicaciones. Se toman como muestra 11 revistas de ciencias sociales editadas en Argentina incluidas en el SCImago Journal & Country Rank. Se analizan sus posiciones en el ranking y el número de citas de esta base y se lo compara con datos recogidos en Google Scholar utilizando la herramienta Publish or Perish. Además, se sistematiza información acerca de su accesibilidad e indicadores de uso y métricas alternativas de sus propios portales, de SciELO, Redalyc y de la base de datos Dimensions. Se pone en evidencia la parcialidad del impacto medido desde Scopus para este grupo de revistas y se demuestra que, al combinar las fuentes, se amplían y diversifican los datos de visibilidad. Para finalizar, se proponen una serie de indicadores básicos de visibilidad integral a partir de las fuentes disponibles que permiten a los gestores de revistas ofrecer datos más certeros de la citación y usos de las revistas y sus artículos.
Tecnología Educativa para el Docente Bibliotecario
Authors: Tourn Luciana Rita
Published: July 2021

La identidad del docente bibliotecario en el contexto de la Sociedad del Conocimiento se configura a través de nuevos sentidos, dado el desarrollo de las Tecnologías de la Información y Comunicación. En este marco, resulta necesario reconstruir el quehacer de su oficio, frente a los múltiples escenarios digitales, las formas de búsqueda, selección y socialización de la información, a partir del uso de internet. Este análisis se articula a los planteos del campo de la Tecnología Educativa, desde donde se comprenden los procesos de enseñanza y aprendizaje y la transmisión de la cultura mediada por tecnologías, fundamentalmente en los ámbitos educativos, entre ellos, la biblioteca escolar. En tal sentido, las transformaciones culturales no sólo resignifican los espacios escolares, sino también las prácticas de lectoescritura y las posiciones pedagógicas del profesional de la bibliotecología.
Homicidios de niñas, niños y adolescentes en el sureste de México, entre 2000 y 2017
Authors: Miranda Juarez Sarai , Evangelista García Angélica Aremy
Published: July 2021

Introducción: México atraviesa por un contexto de violencia creciente que incluye el aumento de homicidios y feminicidios a lo largo del territorio nacional. Los estudios existentes presentan vacíos de corte regional y de grupos de edad, en particular, el de 0 a 17 años. El objetivo de este artículo es describir el impacto de la mortalidad por homicidios sobre la población de 0 a 17 años en el sureste mexicano, una de las regiones más sacrificadas en materia de derechos humanos y bienestar social. Metodología: mediante las estadísticas de mortalidad general del Instituto Nacional de Estadística y Geografía, se calcularon las tasas brutas de mortalidad y las tasas específicas por sexo y grupos de edad correspondientes al período 2000-2017. Se estimó el promedio de Años de Vida Perdidos. El tipo de estudio es descriptivo y analiza el efecto de los homicidios en la tendencia de la mortalidad y la esperanza de vida. Resultados: los resultados mostraron que el más alto porcentaje de homicidios lo obtuvieron los hombres de todos los grupos etarios. En términos del promedio de AVP, las mujeres adolescentes del conjunto de 12 a 17 años evidenciaron los mayores incrementos. Conclusiones: las tasas de mortalidad por homicidio se comportaron heterogéneamente; resalta la vigencia y aumento de ataques letales contra niñas, niños y, especialmente, adolescentes.
Old proverbs for a future sustainable development: An environmental management perspective
Authors: Scarlat Cezar , Petrişor Alexandru-Ionuţ
Published: July 2021

Although the concept of “sustainability” is attributed to Dr. Gro Harlem Brundtland, the principle of inter-generational equity substantiating it is older, at least in the Romanian tradition. This article attempts to take the first steps in looking for the roots of environmental sustainability starting from the traditional wisdom synthesized in proverbs, focusing on the sustainable environmental management. For this purpose, the universal and international principles of environmental law, which are interconnected to the concepts of environmental management (responsibility for protecting the environment) and scientific management in general (functions of the management, decision theory) are used as the backbone of a taxonomic approach. The concept of managerial responsibility takes in ecology the form of individual, group and collective responsibility for the decisions and actions related to the protection of the environment, and also the form of social responsibility. This study continues previous researches of the authors, opening the way to other trans- and interdisciplinary studies. Its main limitation (to Romanian proverbs) gives a possible direction for further research.
Surface water pollution risk assessment of wadis, Mekerra and Saïda, in the North-Western of Algeria
Authors: Guenfoud Ahmed , Benyahia Mohamed , Bouderbala Abdelkader
Published: July 2021

Considered as the main stream of hydrographic network of Mactaa’s basin, in the west highlands of Algeria, both wadis, Mekerra and Saïda, are affected by pollution which is generated by anthropogenic activities. Makara and Saïda wadis cross the urban areas of Sidi-Bel-Abbes and Saïda respectively, in the west of Algeria, which constitute a real problem of human safety. In order to identify the pollution state on these wadis, samples have been collected during three periods of time (June 2011, July 2012 and April 2013) in the goal to characterize the physico-chemical and bacteriological quality of surface water.Results obtained describe clearly the existence of chemical and organic pollution in both wadis at high levels of calcium, magnesium, chlorides, nitrates, nitrites, phosphate, DBO5 and dissolved oxygen. The evaluation of organic pollution index (OPI) confirmed that there is a high organic pollution, upstream, which increases with high water passage towards urban areas of both cities (OPI).The bacteriological analysis results obtained show presence of high contents of faecal bacteria contamination (total coliforms (TC), faecal coliforms (TC) and faecal streptococci(FS))principally in wadi Saïda. The relationship between FC/FS justifies the predominance of human origin than of animal as source of contamination. While, the determination of microbiological quality index (MQI), for each wadi, confirms degradation of microbiological quality by the faecal pollution, mainly in Saïda urban area.
Comprehensive Study on Old Uighur and Chinese Wall Inscriptions in Room B of Newly Excavated Cave 26 in Tuyuq Grottoes, Turfan
Authors: Ma Fu , Lidong Xia
Published: July 2021

The excavation in Tuyuq Grottoes initiated in 2010 has brought about numerous archaeological ﬁnds. In particular, those discovered in Cave 26 on the high platform in the middle of the Western Section are noteworthy. Many wall inscriptions in Old Uighur, as well as Brahmi and Chinese are preserved in the side rooms, releasing important information on the dating and the nature of this cave. They also contribute new data to the ﬁelds of history and linguistics. This paper presents an edition and study of all the 29 inscriptions preserved in Room B, most of which are written in Old Uighur, while others in Chinese.
Green branding as a tool and future potential for destination marketing: Implications from a case study in Veszprém, Hungary
Authors: Lőrincz Katalin , Kruppa-Jakab Éva , Szabó Renáta , Csapó János
Published: July 2021

In recent years, the city of Veszprém was able to obtain several significant achievements concerning its green branding: it was awarded the “Hungary in Bloom” and the “Climate Star” titles together with the “Gold” prize of the Entente Florale Europe award and the special “President’s Award for the Restoration of a Public Open Space”. This case study examines the impact and results of the preparation work and participation in national and an international green branding contests on destination marketing and city image through the analysis of the literature and structured interviews with the theme specialists of the contests. The implications of the research, based on the result of displaying the future vision of Veszprém, offer best practice advice for communities that are considering using green branding tools such as entering a horticultural contest. The results of the research confirm that a potential winning entry, apart from having an attractive cityscape, needs to meet the more novel assessment criteria of these contests as well, i.e. the development of family friendly and accessible infrastructure, multilingual tourist information and digital accessibility.
Resist or perish!
Authors: Rahadianto Sutopo Oki , Ragil Wibawanto Gregorius , Aryo Lukisworo Agustinus
Published: July 2021

This article examines the practice of resistance among young DIY musicians in Yogyakarta, Indonesia in the context of the post-reform era. DIY young musicians negotiate how to provide for their everyday economic needs while also upholding their music genre’s spirit of resistance against market commodification. Lately, commodification not only comes from the music industry but also from the state through neoliberal-oriented creative economy policies. Music falls into the category of a creative sector and is seen as a product to boost economic growth. Based on our empirical data, young musicians resist this through DIY practices in their music scene. We show the struggle of young musicians to sustain their musical values of authenticity (otentisitas) and autonomy (kemandirian). Instead of viewing resistance as homogenous, we observed three modes of resistance: the rookie, the in-between, and the afficionado, based on their level of commitment to being a DIY careerist. Our research offers a real-world example of theories around popular music and youth studies based on the experiences of young Indonesian musicians.
Analysis of the effect of ionic conductivity of electrolyte materials on the solid oxide fuel cell performance
Authors: Sasongko Mega Nur , Perdana Fahrizal , Wijayanti Widya
Published: July 2021

SOFC solid electrolytes are known for their ionic conductivity characteristics, which increase with increasing SOFC operating temperature. Using COMSOL Multiphysics numerical simulation, analysis of SOFC power performance with yttria-stabilized zirconia (YSZ) and lithium sodium carbonate – gadolinium-doped ceria ({LiNa}2CO3-GDC) electrolytes was conducted to determine the potential of these electrolytes in their application in SOFC. The ionic conductivity of YSZ was differentiated based on the mole value of the yttria content, namely 8, 8.95, 10 and 11.54 mol. Meanwhile, GDC varied based on the (LiNa)2CO3 content such as 7.8, 10, 16.8 and 30 %. With the numerical model, the calculation error is an average of 7.32 % and 6.89 % for the experimental power and voltage values. In SOFC with the YSZ electrolyte, it was found that the power output can increase 26.4–35 times with an increase in operating temperature from 500 °C to 750 °C. SOFC with 8YSZ can produce the highest power compared to other YSZ, which is 123 A/m2 at a current of 198 A/m2 with an operating temperature of 500 °C and 3,440 A/m2 at a current of 5,549 A/m2 with an operating temperature of 750 °C. Whereas in SOFC with the GDC electrolyte, it was found that the power output can increase 18.6–22.6 times with an increase in operating temperature from 500 °C to 750 °C. SOFC with 30 % (LiNa)2CO3-GDC produced the highest power compared to other GDC, which is 231 A/m2 at a current of 444 A/m2 with an operating temperature of 500 °C and 5,240 A/m2 at a current of 10,077 A/m2 with an operating temperature of 750 °C. YSZ also showed the potential for an increase in power output as the SOFC temperature increases above 750 °C, while the 30 % variation (LiNa)2CO3-GDC shows a limited increase in ionic conductivity at 750 °C
Development of product complexity index in 3D models using a hybrid feature recognition method with rule-based and graph-based methods
Authors: Budiono Hendri Dwi Saptioratri , Hadiwardoyo Finno Ariandiyudha
Published: July 2021

A machining process is very dependent on the model created. The more complicated the model, the greater the design difficulty and the greater the machining process. Reduced production costs can help a company increase profits. A focus on production cost can be achieved in a number of ways, the first of which is by replacing materials or changing the design. It is better to reduce product costs during the design stage than during the manufacturing stage. The main objective of this research is to develop an application that can recognize features in a CAD program and calculate the complexity index of shapes in real time. In this study, the prismatic features and slab features classified by Jong-Yun Jung were used. The feature recognition method applied in this study is a hybrid of the rule-based and graph-based methods, which uses the STL file developed by Sunil and Pande to obtain all the information needed. Then, the results are extracted from feature recognition data and are used to calculate the product complexity index of the model being studied. This study applied the product complexity index, following the model developed earlier by El Maraghy. Validation is performed by comparing the software count with the complexity index calculated with the STEP method by Hendri and Sholeh et al. This research develops a program that recognizes features in CAD software and calculates the index complexity of shapes in real time. This will allow designers to calculate the expected complexity value during the design process. As a result, the estimated production cost can be seen early on. Finally, this software is tested for calculating the index values for the complexity of a combined features model. The use of eight slots and eight pockets as a benchmark scoring for shape produces a more accurate product complexity index
Determining the effect of dispersed aluminum particles on the functional properties of polymeric composites based on polyvinylidene fluoride
Authors: Lysenkov Eduard , Klymenko Leonid
Published: July 2021

Polymeric materials that contain inorganic fillers demonstrate a unique set of physical properties due to the combination of matrix elasticity and filler strength. This paper reports determining the effect of dispersed aluminum particles on the properties of polyvinylidene fluoride-based materials. This study result is the fabrication of a series of composite materials using a piston extruder. Their functional characteristics have been explored using the methods of thermophysical and mechanical analysis, dilatometry, and acoustic spectroscopy. It was established that the introduction of dispersed aluminum particles leads to the loosening of the matrix, which may indicate the transition of macro macromolecules from the crystalline phase to the boundary layer around the filler. This feature of structure formation and the uniform distribution of filler particles ensured the improvement of the functional characteristics of the materials obtained. It has been shown that with an increase in the content of filler in the system to 5 % the thermal conductivity increases from 0.17 W/(m·K) to 1.55 W/(m·K). The introduction of the filler leads to an improvement in the heat resistance of the materials obtained, by 17 K. The increase in both melting point and destructiveness is explained by the formation of a more perfect polymer structure with a higher degree of crystallinity. An increase in the speed of ultrasound propagation was identified, by 67 %, as well as in the tensile strength, by 36 %, in the materials obtained, which can be explained by contributions from the filler, which has greater sound conductivity and mechanical strength than the polymer matrix. Such systems show the reinforcing effect of aluminum particles on the polymer matrix, so they could be used as structural materials with improved functional characteristics
Determination of the electrical power increase at the generator terminals of a nuclear power plant unit at different condenser states
Authors: Bratkovska Kateryna , Liush Yuliya
Published: July 2021

It is shown that the technical condition of condensing devices of steam turbines largely determines the amount of electricity losses, reliable and economical operation of NPP units. Analysis of the heat transfer process in the condenser showed that the main causes of load reduction are determined by rising cooling water temperature and deviation of steam pressure from normal value. It is shown that among diagnostic parameters except leakage volumes there must be an assessment of contamination of the heat transfer surface which significantly affects the reduction of electricity generation.
The modernization main points of the condenser of the Zaporizhzhya NPP power unit No. 3 on the principle of "block-modular" design developed by PJSC "Turboatom" and the characteristics of the condenser provided by the new design are considered.
To reflect the real mode of operation of the condensing unit, it is proposed to model the contamination of the heat exchange surface and the presence of leakages in the condenser space using the method of thermal calculation of the condenser by iterative methods. It was found that reducing the increase in electricity generation as a result of the effects of the study factors can partially or even completely absorb the effect of upgrading the condenser plant. It will provide a significant increase in electricity generation with relatively low capital investment compared to construction of new NPP power units and improve the accuracy of power generation forecasts.
Operational algorithm for a heat detector used in motor vehicles
Authors: Kushnir Andrii , Kopchak Bohdan , Gavryliuk Andrii
Published: July 2021

In most cases, fixed temperature heat detectors are used to detect fire in vehicles. The response parameter of such detectors is constant. The time of fire detection by a fire detector, as well as the probability of its false operation, are affected by heat flux from an internal combustion engine. This paper reports the development and investigation of an operational algorithm of the fixed-dynamic heat detectors with variable response parameters. Depending on the temperature influence exerted by engine operation modes, a given algorithm automatically changes a value of the minimal static response temperature of a detector, as well as value of the rate of rise in the temperature of its response. The experimental results showed that in the initial period of engine operation, the temperature change rate in the engine compartment fluctuates and is the largest. It can exceed 290 °С/min. However, regardless of the type of vehicle and the type of engine, when the temperature reaches technological, the temperature change rate would vary within small limits, approximately 30÷50 °С/min. The study results from the Simulink software package (USA) in the MATLAB programming environment (USA) confirm the effectiveness of the programmed operational algorithm of a thermal fire detector. The developed algorithm of a fire detector's operation makes it possible to detect the fire at an early stage and reduce the cases of the device's false response. The fire detector responded to both the maximal and dynamic components. As regards the maximal component, the proposed detector is triggered about 2.3 times faster than the classic maximal thermal fire detector. Detection of fire at an early stage makes it possible to quickly use the fire extinguishing system
The possibility to apply the Frenet trihedron and formulas for the complex movement of a point on a plane with the predefined plane displacement
Authors: Volina Tatiana , Pylypaka Serhii , Nesvidomin Victor , Pavlov Aleksandr , Dranovska Svitlana
Published: July 2021

Material particles interact with the working moving surfaces of machines in various technological processes. Mechanics considers a technique to describe the movement of a point and decompose the speed and acceleration into single unit vectors of the accompanying trajectory trihedron for simple movement. The shape of the spatial curve uniquely sets the movement of the accompanying Frenet trihedral as a solid body. This paper has considered the relative movement of a material particle in the static plane of the accompanying Frenet trihedron, which moves along a flat curve with variable curvature. Frenet formulas were used to build a system of differential equations of relative particle movement. In contrast to the conventional approach, the chosen independent variable was not the time but the length of the arc of the guide curve along which the trihedron moves. The system of equations has been built in the projections onto the unit vectors of the moving trihedron; it has been solved by numerical methods. The use of the accompanying curve trihedron as a moving coordinate system makes it possible to solve the problems of the complex movement of a point. The shape of the curve guide assigned by parametric equations in its length function determines the portable movement of the trihedron and makes it possible to use Frenet formulas to describe the relative movement of a point in the trihedron system. This approach enables setting the portable movement of the trihedron osculating plane along a curve with variable curvature, thereby revealing additional possibilities for solving problems on a complex movement of a point at which rotational motion around a fixed axis is a partial case. The proposed approach has been considered using an example of the relative movement of cargo in the body of a truck moving along the road with a curvilinear axis of variable curvature. The charts of the relative trajectory of cargo slip and the relative speed for the predefined speed of the truck have been constructed
Comprehensive assessment of the influence of structural friction in a vehicle suspension on its performance
Authors: Pisarev Valeriy
Published: July 2021

Decision-making regarding the application of any new structure at the design stage requires in practice that it should be compared with the existing one by many indicators. A special feature of the new design of hydropneumatic suspension is the existence of movable connections (screw and splined) as parts of the hydropneumatic element. The presence of structural friction in movable connections requires, in particular, an assessment of the impact of this friction on the process of oscillations when moving through crossed terrain based on comparative analysis. The comprehensive estimate chosen for comparison includes operational properties in terms of ergonomics (smooth movement) and adhesion to the support surface (effort in the contact of wheels with the support surface).
The results of a theoretical study involving a vehicle with parameters (weight, dimensions) close to armored personnel carriers BTR70, BTR80, but with hydropneumatic suspensions, demonstrated that when driving on crossed terrain with speeds up to 65 km/h there is a significant reserve in terms of ergonomics. Regardless of the presence (absence) of structural friction, at friction coefficients of up to 0.085. When moving on the surface with large irregularities, the reserve for the maximum allowable (3 g) acceleration in a driver seat is 4.708 times (there is no structural friction) and 3.768 times (structural friction is present). When moving on the surface with small irregularities, the reserve for the maximum permissible (0.5 g) acceleration in a driver seat is 2.093 times (there is no structural friction) and 2.616 times (structural friction is present).
Under the most dangerous modes of movement (at the highest speeds) when driving over small irregularities, the presence of structural friction has a positive effect both in terms of ergonomics and stability. Thus, when driving at a speed of 65.679 km/h, the minimum clutch margin is 1.4 times greater, and the acceleration is 1.249 times smaller
Correlation between the emulsion oligomerization parameters for C9 fraction and the characteristics of hydrocarbon resins
Authors: Subtelnyy Roman , Kichura Dariia , Dzinyak Bohdan
Published: July 2021

This paper investigates the production of hydrocarbon resins by emulsion oligomerization of the С9 fraction hydrocarbons in liquid by-products of oil refining. Such oligomers have a wide range of applications as film-forming agents in paints and anti-color coatings.
Emulsion oligomerization was carried out using emulsifiers of the first and second kind. The study was performed at different values of the reaction temperature of the reaction duration, the intensity of agitation; concentrations of the emulsifier; С9:water fraction ratio. The resulting products were estimated according to the following indicators: the yield, unsaturation degree, softening temperature, mean molecular weight, color.
Statistical analysis was carried out, the correlation of parameters of emulsion oligomerization and the yield and characteristics of oligomers was established. Given that, it would be possible to establish the optimal conditions for emulsion oligomerization and predict the properties of the products obtained.
Specifically, it was established that the yield of hydrocarbon resins does not correlate with the reaction temperature (0.15 and 0.30) and the concentration of emulsifiers (0.08 and 0.03). It was proven that in the intervals studied the variable yield of oligomers depends on the duration of the reaction (correlation 0.88 and 0.81). In the case of oligomerization in the reverse emulsion, a significant correlation with the yield is also demonstrated by agitation intensity (0.51) and a С9:water fraction ratio (0.51). That has made it possible to derive an equation of the yield multiple linear regression dependent on the most significant process parameters. The high values of the yield and bromine number correlation (0.94 and 0.93) give grounds to argue about the progress of oligomerization reaction. The relationship among the characteristics of oligomers has been confirmed. This indicates the possibility of directed adjustment of certain characteristics of hydrocarbon resins.
Analysis of the effect of stirrer and container rotation direction on mixing index (Ip)
Authors: Susilo Sugeng Hadi , Asrori Asrori , Gumono Gumono
Published: July 2021

The paper discusses the effect of the stirrer and container rotation direction on the mixing index (Ip). The chaos theory is the result of an in-depth study of various problems that cannot be answered by the two previous major theories, namely quantum mechanics and the theory of relativity. Effective mixing of the flow area does not depend on rapid stirring.
This study uses a container with a double stirrer, camera, programmable logic controller, tachometer, 6 A adapter, and a computer. DC electric motor (25 V) for turning stirrers and housings. The diameter of the primary and secondary stirrers is Dp=38 mm and Ds=17 mm. The diameter of the container made of transparent plastic is Dw=160 mm and height is 170 mm. Primary stirrer rotation (np)=10 rpm, secondary stirrer rotation (ns)=22.3 rpm, and container rotation (nw)=13 rpm, the angular velocity of the container is Ww=360° while the angular speed of the primary stirrer is Wp=180°. The liquid consists of a mixture of water and paint (white). For dye, a mixture of water and paint (red) is used. For testing the Brookfield viscometer, the viscosity of the liquid and dye is used. The results showed that turning the stirrer in the opposite direction to the container, there will be stretching, bending, and folding around the stirrer, and the smallest mixing index was P2V-b (0.94). In addition, based on the mixing index value above, the highest mixing effectiveness level is obtained, namely: P2V-b, P2S-b, P2B-b, P2V-a, P2B-a, and finally P2S-a. The mixing index is inversely related to the effectiveness level. So the highest effectiveness level is given by the following treatment: 1. Variation rotation (between opposite rotating mixers), 2. Opposite rotation (stirrer rotation opposite direction to the container), 3. Unidirectional rotation (stirrer rotation in the direction of the container)
Design of a recommendation system based on the transition graph
Authors: Guk Natalia , Verba Olga , Yevlakov Vladyslav
Published: July 2021

A recommendation system has been built for a web resource’s users that applies statistics about user activities to provide recommendations. The purpose of the system operation is to provide recommendations in the form of an orderly sequence of HTML pages of the resource suggested for the user. The ranking procedure uses statistical information about user transitions between web resource pages. The web resource model is represented in the form of a web graph; the user behavior model is shown as a graph of transitions between resource pages. The web graph is represented by an adjacency matrix; for the transition graph, a weighted matrix of probabilities of transitions between the vertices of the graph has been constructed. It was taken into consideration that user transitions between pages of a web resource may involve entering a URL in the address bar of a browser or by clicking on a link in the current page. The user’s transition between vertices in a finite graph according to probabilities determined by the weight of the graph’s edges is represented by a homogeneous Markov chain and is considered a process of random walk on the graph with the possibility of moving to a random vertex. Random Walk with Restarts was used to rank web resource pages for a particular user. Numerical analysis has been performed for an actual online store website. The initial data on user sessions are divided into training and test samples. According to the training sample, a weighted matrix of the probability of user transitions between web resource pages was constructed. To assess the quality of the built recommendation system, the accuracy, completeness, and Half-life Utility metrics were used. On the elements of the test sample, the accuracy value of 65‒68 % was obtained, the optimal number of elements in the recommendation list was determined. The influence of model parameters on the quality of recommendation systems was investigated.
Investigating the influence of nano-economy management channels on global transformations in the world
Authors: Ostapenko Tetiana , Onopriienko Oleksandr , Hrashchenko Iryna , Danilova Elvira
Published: July 2021

The problem under investigation is determined by the fact that enterprises consist of separate economic agents that play an increasingly important role in production processes and their management. The channels of such management provide the transfer of positive experience of the totality of economic agents to the global environment. Due to the permanent process of transformations in the world caused by this influence, the probability of being on the sidelines is a problem for most business entities. Their competitiveness and integration into the world economic networks depend on high-quality management and wide application of innovative technologies, including nanotechnologies.
The conducted study revealed that:
– nano-economy consists of baby economy, human economy, and the economy of nanotechnologies;
– the human economy is the central link and the main leader of the impact of nano-economy on global markets. The main components of its management are self-management, self-marketing, and innovative management of the organization personnel;
– nanotechnologies, the economics of nanotechnologies, and transfer of nano-knowledge are at the initial stage of their development;
– the impact of nano-economy on the development of the global environment is carried out through the functions of nanomanagement;
– the management channels of the nano-economy do not affect the entry of countries with transition economies into the global environment due to the fact that they lack the system of nano-economy. This is proved by multifactor analysis of the impact of nano-economy on exports. The obtained indicators, such as exports of USD 57 billion (by the exchange rate of 2021), 281 universities, 1,941,701 business entities, and 135 thousand scientific and technical institutions, do not correlate and determine low direct and inverse indicators of dependence.
The results of the study can be used:
– at separate enterprises – by using innovative personnel management, including motivating and training of personnel in self-management and self-marketing; 
– at the state and regional levels – by creating favorable conditions for the development of baby economy in countries with transition economies and by promoting optimal solutions of separate economic agents
Definition of the influence of pulsed deposition modes on the electrochromic properties of Ni(OH)2-polyvinyl alcohol films
Authors: Kotok Valerii , Kovalenko Vadym
Published: July 2021

In this work, the influence of some types of the pulsed deposition mode of electrochromic films from aqueous solutions of nickel nitrate with the addition of polyvinyl alcohol was investigated. Glass coated with a fluorine-doped tin oxide film was used as the basis for deposition. The deposition of nickel (II) hydroxide – polyvinyl alcohol electrochromic films was carried out in three pulsed modes: –0.2 mA/cm2×5 s, 0 mA/cm2×5 s (10 minutes); –0.5 mA/cm2×2 s, 0 mA/cm2×8 s (10 minutes); –1 mA/cm2×1 s, 0 mA/cm2×9 s. In this case, the amount of electricity used for the formation of thin-film electrodes was the same for all samples.
The resulting films showed dramatic differences in electrochemical, optical, and quality characteristics. The sample obtained in the mode of the highest cathode current density and the duration of the no-current condition (1 mA/cm2×1 s, 0 mA/cm2×9 s) had the worst specific capacity and optical characteristics. This sample was characterized by the highest number of coating defects and color non-uniformity as well.
The sample, which was obtained at average current densities (–0.5 mA/cm2×2 s, 0 mA/cm2×8 s), had the highest specific characteristics among the electrodes in the series. The coating was uniform and solid. Also, this sample had the greatest stability of the coloration depth value, which varied from 79.1 to 78.1 % (first to fifth cycles).
The sample obtained in the mode –0.2 mA/cm2×5 s, 0 mA/cm2×5 s showed moderate specific indicators, however, there were some coating defects.
According to the results obtained, a mechanism was proposed that explained the differences in the characteristics of thin-film electrodes formed in different modes. This mechanism consists of changing the time of non-stationary processes and the distribution of the current density with a change in the value of the deposition current density, the duration of the cathode period, and the no-current condition.
Oil wells hydrate formation regularities
Authors: Liashenko Anna , Makarenko Valeriy , Vynnykov Yuriy , Petrash Oleksandr
Published: July 2021

The paper considers the process of hydrate-paraffin deposits formation in oil wells. Due to the research with the author's specially designed laboratory equipment – an experimental installation containing a technological unit and an information-measuring system, the most favorable pressure-temperature conditions of hydrate formation in a wide range of pressure (0.1–120 MPa) and temperature (from –20 to +80 °C) were determined. The experimental results made it possible to determine the conditions required for hydrate deposits and iron (Fe) oxides in the range of temperature from –15 to +60 °C and pressure from 0 to 60 MPa. These results are confirmed by thermodynamic calculations of the oil-gas-hydrate phase equilibria in the annulus of the well. Data processing was performed using the methods of correlation, dispersion and regression analysis, which allowed comparing the processes of hydrates and iron (Fe) oxides formation in the annulus of oil wells. The results of the study can be used to prevent and eliminate hydrate-paraffin plugs in the downhole equipment of oil wells, and also to determine the operation mode of the well for long-term operation of the downhole equipment without complications, accidents and stops for repair works, which reduces downtime.
Development of an experimental-estimation method for estimating indices of residual life of a radio technical complex
Authors: Lukianchuk Vadim , Lanetskii Boris , Khudov Hennadii , Terebuha Ivan , Zvieriev Oleksii , Shknai Oleh , Zapara Denys , Petruk Serhii , Dyptan Valentyn , Piavchuk Oleksandr
Published: July 2021

To implement the operation of a radio technical complex according to its technical condition, it is necessary to jointly evaluate its reliability and residual life indices with required accuracy and reliability and minimization of the scope of special tests. The known methods are focused on separate solutions to the problems of estimating these indices as applied to the regulated strategy.
To solve this problem, general provisions have been developed for estimating the indices of residual life of the radio technical complex including the accepted assumptions and limitations for developing the method, the estimated indices, and criteria of limiting state. The developed experiment-calculated method is a set of mathematical models of change of the reliability indices of a radio technical complex depending on calendar duration of operation or total operating time and analytical models of estimating the indices of its residual life.
The mathematical models of change of mean time between failures, the probability of failure-free switching, and the parameter of the flow of failures of the radio technical complex depending on calendar duration of operation or the total operating time were presented in a form of regressive dependences. Analytical models of estimating the residual life indices are ratios for calculating the "average residual service life (resource)" according to the technical and economic criterion using regression-time dependences of the reliability indices.
The developed experiment-calculated method can be used to estimate the indices of residual life of the radio technical complex with acceptable accuracy (no more than 2 quarters) and reliability (no worse than 0.8). In this case, the duration of the intervals of predicting the reliability indices should be 0.5 to 1 year and the corresponding observation intervals should be more than 1 year