bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality of Eucheuma cottonii seaweed cultivated in Lampung waters
Authors: Subaryono  , Kusumawati R 
Published: December 2019

Abstract
This study was aimed to observe the quality of Eucheuma cottonii dried seaweed produced from seaweed farmers in Lampung, especially in its main production centers namely sub-district Ketapang, south Lampung. Seaweed was taken from three locations namely Ruguk, Legundi and Tri Dharma Yoga Village. The parameters observed were included seaweed moisture content, clean anhydrous weed (CAW), ash content, yield, and the quality of carrageenan produced. The results showed that seaweed moisture content ranged from 21.71 to 33.48%, CAW 37.53-40.72%, ash content 33.68-43.08%, and carrageenan yield 11.35-13.57%. From the results of the observation it was concluded that the quality of seaweed from Legundi Village was the best compared to other villages.
Moving pattern and feeding behavior of blue-spotted ribbontail ray (Taeniura lymma ) in aquaria environment
Authors: Madduppa H , Irawan D , Zamani N P , Subhan B , Arafat D 
Published: December 2019

Abstract
The moving pattern and feeding behavior of blue-spotted ribbontail ray (Taeniura lymma ) in aquaria environment was studied within 27 days. The moving pattern observations (e.g. movement, respond to stimulation, feeding and breathing activities) were conducted by direct observation and by recording their activities during day and night. The feeding behavior was observed by feeding them in a variety of food. The study showed that ray was active at day and becoming passive during night. The moving pattern included maneuver in vertical and horizontal directions, walk and jump on aquaria bottom, and fast reflective movements. The ray showed ability in prey hunting, more like to fed living fodder with a smooth texture, not a corpse eater, had abilities to modulate breathing rate regarding varying activities, and had skills to acclimatize in strong inflow changes of aeration and water flow.
The inverse vibration problem for fixed beam submerged in fluid
Authors: Havlásek M , Habán V , Hudec M , Pochylý F 
Published: December 2019

Abstract
Description of dynamic behaviour of the structures is based on the mass, damping and stiffness matrices. Unfortunately, this description is inapplicable in case of the fluid-structure interaction (FSI), because the matrices of system, which consists of the structure and ambient fluid, are generally not known. The matrices of system, describing the FSI, can be determined by solution of inverse vibration problem, which is an approach employing the spectral matrix and modal matrices of analysed system. The eigenvalues for creation of the spectral matrix are determined based on experimental measurement. The results of experiment can be verified by numerical simulation. The modal matrices of structure submerged in fluid can be given by experiment, which is not simple in FSI problem, or by acoustic modal analysis. Third approach for determination of the modal matrices works with the assumption, that the eigenvectors of structure are not influenced by the fluid and are identical to the eigenvectors of structure without the ambient fluid. This assumption is generally correct for majority of FSI problems. Described method is demonstrated on determination of the matrices of dynamic systems of the fixed beam submerged in water.
Using DGCM to predict transient flow in plastic pipe
Authors: Urbanowicz Kamil , Bergant Anton , Duan Huan-Feng , Stosiak Michal , Firkowski Mateusz 
Published: December 2019

Abstract
Transient flows with cavitation are commonly existent and observed in pressurized conveyance systems. The occurrence of large cavitation caverns accompanying hydraulic impacts in the pressurized pipes is particularly dangerous. There may then be interference of pressure waves traveling inside the pipe (especially between initial and secondary pressure waves). The maximum instantaneous pressures can rise in the most dangerous scenario to – magnitude that are twice as large as those calculated with a classic formula of Joukowsky. To protect these systems at the design stage it is advisable to estimate large pressure pulsations using appropriate numerical models. In this work transient cavitating flow in the plastic pipe was modeled using the modified discrete gas cavity model (DGCM). Retarded strain occurring in the studied plastic pipe was modeled with the aid of a convolutional integral of stress history and a derivative of the creep compliance function of the plastic pipe wall. In the simulation, the unsteady wall shear stress was determined using the recent Urbanowicz’s computationally effective method.
Wall Shear Stress in Pulsating Pipe Flow at Resonance Conditions
Authors: Gregorc Jurij , Bergant Anton , Urbanowicz Kamil , Tijsseling Arris 
Published: December 2019

Abstract
Hydraulic vibrations in liquid-filled pipelines may cause unwanted operational problems. Wall shear stress and consequential damping can reduce the harmful effects of vibrations close to resonance. A large-scale pipeline apparatus at Deltares, Delft, The Netherlands, has been used for pulsating pipe flow tests. The apparatus consists of a constant-head tank, a horizontal 206 mm diameter 49 meters long steel pipe and an oscillating valve at the downstream end. Wall shear stress has been measured by a number of hot-film sensors. Tests have been performed with an average flow Reynolds number of about 22,000. Results of a hydraulic resonance case with oscillating frequency fex
= 5 Hz are presented. Pipe wall vibrations for this case are small. The shape of the velocity profile at resonance conditions is a typical unsteady-state velocity profile with reverse flow near the pipe wall. The CFD study in an axisymmetric domain was conducted to better understand the pulsating flow phenomena. Different settings of boundary conditions, based on the experimental investigations, were used. The CFD results show the unsteady character of wall shear stress at resonance. This phenomenon has not been observed in the measured results to such an extent. The measured shear stress resembles quasi-steady behaviour.
Simulation of a shut-down transient in the Francis-99 turbine model
Authors: Uppström L , Fahlbeck J , Lillberg E , Nilsson H 
Published: December 2019

Abstract
Due to the new intermittent electric energy sources, hydropower is forced to run more and more at off-design conditions and to regulate the operating conditions. This causes flow instabilities with pressure fluctuations, and load variations that may deteriorate the machine. Previous numerical research on the flow in water turbines has mainly focused on steady operating conditions at BEP and off-design. More knowledge is needed on transients between operating conditions, and start-up and shut-down procedures. This requires dynamic meshes that both rotate the runner, using a coupling interface to the non-rotating part of the mesh, and morph the guide vane mesh due to the change in guide vane angle during the transient. Special care needs to be taken to apply boundary conditions that resemble the experimental condition to be used for validation. The present work addresses a shut-down transient of the Francis-99 turbine (https://www.ntnu.edu/nvks/francis-99), using OpenFOAM-2.3.x. Turbulence is modelled by LES based on the dynamic one-equation eddy viscosity sub-grid model and the cube root volume filter width, although the temporal and spatial resolution requirements have not been assessed in these preliminary results. The inlet and outlet boundary conditions are set using pressure conditions. The outlet static pressure is taken from the experiment at BEP. The inlet total pressure is adjusted to yield the same flow rate as in the experiment at BEP. The flow rate is given by the solution. The runner region of the mesh rotates with a solid-body rotation, while the guide vane region of the mesh is morphing due to the continuous change in guide vane angle. Rotating and stationary parts of the mesh are coupled with an arbitrary mesh interface (AMI). The results show that the methodology can be used to capture the experimentally observed flow features during transients.
Cavitation erosion prediction based on a multi-scale method
Authors: Plastre Lydia , Devals Christophe , Gauthier Maxime , Nennemann Bernd , Trépanier Jean-Yves , Guibault François 
Published: December 2019

Abstract
In hydraulic turbines, cavitation has unwanted consequences such as vibrations, noise, or material degradation. Thus, developping a method which can anticipate this phenomenon with good accuracy is vital from the designer’s perspective.
This work aims at predicting two aspects of cavitation erosion: determining areas most endangered, and quantifying cavitation erosion in a relative way.
Experimental investigation of vortex ring formation as a consequence of spiral vortex re-connection
Authors: Štefan D , Rudolf P , Hudec M , Uruba V , Procházka P , Urban O 
Published: December 2019

Abstract
The unsteady shape variation of a cavitating spiral vortex is experimentally studied pointing out the repetitive creation of vortex ring (or vortex loop). To generate the spiral vortex structure, a newly designed vortex generator is employed. This generator is used to study the decelerated swirling flow leading to the spiral vortex formation as a consequence of spiral vortex breakdown, which is considered to be the main triggering mechanism for the occurrence of the coherent vortex rope structure in the Francis turbine draft tube operated at part load conditions. Thanks to its design, the vortex generator enables to change the ratio between fluxes of axial momentum and tangential moment of momentum of generated swirl. Using this set-up, the behavior of the vortex structure changes in a similar way as the flow rate variation in the draft tube of Francis turbine. At certain flow conditions, the spiral vortex movement is characterized by sudden spiral entanglement leading to disconnection of a vortex ring and followed by spiral reconnection. Thanks to the transparent diffuser of the swirl generator apparatus, both high-speed camera recording of the cavitating vortex and PIV measurements of velocity fields at cavitationfree conditions are employed. The main aim of this paper is to link the visual observation of the above described vortex dynamics with the velocity fields measured in one longitudinal and one cross-sectional planes.
Methods of theoretical researches the non-linear electrophysical properties of solid dielectrics with compound crystalline structure
Authors: Kalytka V A , Neshina Y G , Madi P Sh , Naboko Y P 
Published: December 2019

Abstract
Methods quasiclassical kinetic theory investigate the phenomena of nonlinear ion-relaxation polarization in solid dielectrics with a compound structure of the crystal lattice. As a particular case, the mechanism of nonlinear proton-relaxation polarization in hydrogen-bonded crystals (HBC), classified according the electrophysical properties as proton semiconductors and dielectrics (PSD) is theoretically studied. Generalized kinetic equation and spectra of complex permittivity (CP), which allow to describe the nonlinear properties of dielectric losses in HBC in range of ultra-low temperatures (1- 10 K) and low fields (100 kV/m - 1000 kV/m), and in range of ultra-high temperatures (550-1500 K) and strong fields (10 MV/m - 1000 MV/m). The scientific and practical significance of received results consists in development of the theoretical basis of algorithm for computer prediction of materials properties and parameters that are functional elements of technological schemes of industrial installations and systems.
Evolution of the fractal structure
Authors: Kravchenko G M , Pudanova L I 
Published: December 2019

Abstract
The principles of fractal geometry are applicable in the development of new designs based on fractal shaping and the evolution of fractal structures. It’s necessary to use new materials to design fractal structure. The evolution of the structure is characterized by optimization of the initial geometry in the process of iteration. Thus, the fractal structures of older generations from innovative material have the best indicators of reliability. The aim of this study is to develop new designs using the principles of fractal shaping. To reduce the weight of the elements of the building frame in parallel with the evolution of the structure, it is necessary to explore innovative materials with certain material properties. The development of fractal structures requires the creation of new technologies and materials.
The rotating layer mechanics of polydisperse particles in the continuous action pneumatic mixers
Authors: Orekhova T N , Prokopenko V S , Okushko V V , Kachaev A E 
Published: December 2019

AbstractThe article presents the dry construction mixtures various components polydisperse flow with light and heavy particles rotating layer mechanics numerical and experimental study results. The obtained results allow to control the polydisperse flow layer rotation while it is mixing in the pneumatic mixer chamber working volume. The conditions for estimating the braking parameter of a rotating layer with polydisperse particles on the basis of which the working mixing chamber necessary dimensions can be effectively selected were analytically obtained.
The study on soils external friction
Authors: Kocherzhenko V V 
Published: December 2019

Abstract
The molecular-mechanical (adhesion-deformation) theory of friction with respect to a dispersed medium was confirmed in the article on the basis of theoretical and experimental soils external friction studies. At the same time, the soil particles interaction calculated model of a spherical shape with a smooth polymer surface was developed and an expression for determining the area of their actual contact with a solid surface under the action of a load N was obtained. The calculated contact area results‘ comparison for coarse and fine sand showed satisfactory convergence with the experimental data (discrepancy does not exceed 8-10%). The particles behavior analysis of the dispersed medium adjacent to a solid smooth surface under shear, presented in the computational model, was confirmed by the experimentally obtained and fixed plastic deformations of the polymer surface layer. The experimental studies using a soil tribomer allowed to determine the deformation proportion and adhesive components in the external friction force of sandy and clay soils. Using the obtained dependencies for calculating and contacting soil particles with a solid surface, a method for calculating the coefficient of external friction of the soil based on the molecular-mechanical theory of friction is proposed.
A numerical solution to nonlinear lens-shaped membrane-pneumatic systems using the iterative-incremental approach with account for air elastic properties
Authors: Amoyan M F , Kim A Yu , Polnikov S V 
Published: December 2019

Abstract
The authors present an improved methodology for a computer-based static analysis of geometrically and physically nonlinear lens-shaped membrane-pneumatic systems relating the large-span structures coverings using the iterative -incremental technique with the finite element method stepwise application, the universal gas equation, and the improved Euler-Cauchy numerical procedure.
An Algorithm for the Numerical Calculation of Nonlinear Lens-Shaped Membrane-Pneumatic Systems Created by the Incremental-Iterative Method with Account for the air Pressure Aftereffect
Authors: Amoyan M. F. , Kim A. Yu. , Polnikov S. V. 
Published: December 2019

Abstract
The authors have developed a method for the computer-aided static calculation of the large span structures geometrically and physically nonlinear lens-shaped membrane-pneumatic systems using the incremental-iterative algorithm with a stepwise application of the finite elements method in the displacement method form, the universal gas equation, and the improved Euler-Cauchy numerical procedure of the third order accuracy.
Gas equipment maintenance
Authors: Hashim Al-Maidi A A , Chernetsov D , Rodionov Yu 
Published: December 2019

Abstract
The article describes the operation features of the vehicle and tractors transport, equipped with gas equipment. Bottle-gas driven automobiles and tractors transport compared to cars and tractors transport, working on liquid fuel, have a number of features caused by the presence of their gas supply system under pressure. The organization and maintenance features of both the power supply system and the vehicle as a whole are taken into account.
The Foundations with Composite Reinforcing Various Types Work Analysis
Authors: Subbotin A , Shagina A , Skibin G , Shutova M 
Published: December 2019

Abstract
The article deals with the composite reinforcement use in the foundations’ construction under difficult geological conditions and aggressive groundwater. The pile foundation of a two-story cottage was calculated using two types of reinforcement in the pile cap: traditional metal reinforcement and composite fiberglass. The modern regulatory documents requirements governing the calculation of structures with composite reinforcement were taken into account. The use composite reinforcement has been revealed not to give a significant advantage in the pile foundations cost, it is effective when the structure is used in aggressive environments: the resistance of fiberglass reinforcement plays a crucial role in combination with special concretes.
The industrial buildings settlement foundations calculation made taking into account the soils vibro-creep
Authors: Sobolev E , Morev D 
Published: December 2019

Abstract
The present study focuses on the interaction of soil and the foundation under vibration and cyclic loading arising from the operation of dynamic machinery of industrial buildings. The paper presents the methods for predicting the behavior of sand under vibration loads on the example of testing in a triaxial compression device with the possibility of creating dynamic loading. During the final stage of testing, the values of the sample’s additional deformations were obtained due to the vertical vibration load action of a given frequency under conditions of consolidated-drained triaxial compression. The vibro-creep coefficient was obtained, which makes it possible to determine the reduced Young's modulus, which makes it possible to use it in the sediment calculations by the layer-by-layer summation method. The dependence graphs of the Young's modulus on the pressure of the all-round reduction and vertical deformation on the number of cycles “load – discharge” are given. Analytical and numerical calculations of vertical deformations on the elastic base with vibration load are performed. The possibility of obtaining the coefficient of vibro-creep for different types of sandy soils in tabular form with the aim of simplifying the foundations additional movements calculation of the machines with dynamic loads is presented.
Trends in the low-rise housing development in the rural settlements’ projects in Southern Russia
Authors: Vorobeva A M , Tkachenko M V , Veropotvelyan A S 
Published: December 2019

Abstract
One of the main tasks stipulated by the government federal target program “HOUSING” for 2015-2020 is to provide the population with comfortable housing. In the course of its implementation, the state housing policy legal and organizational frameworks were developed, its priority areas were identified and the implementation mechanisms were developed. The funds amount envisaged in the Russian Federation constituent entities budgets and local budgets to finance the sub-program activities has significantly increased.
Prospects for the multi-storey buildings construction using wooden structures
Authors: Konovalov M , Kozinets G 
Published: December 2019

Abstract
This article presents the multi-storey wooden construction development problem in Russia. The paper presents the work results on the possible mixed systems development for multi-storey buildings, where wood is embedded in the building structural system. In addition, the wood introduction effects are evaluated.
A 16-storey business center, with dimensions in terms of 22x44 meters was considered. As a result of the research for this object, a comparative analysis of a reference building made of monolithic reinforced concrete and four concepts, made entirely or partially of wood, was performed. According to the analysis results, strength, technical and economic indicators were calculated, and the conclusions and recommendations of advisory nature were made.
BIM and Cost Estimation Issues (5D): Case of Armenia
Authors: Ghazaryan Marine 
Published: December 2019

Abstract
Building Information Modelling (BIM) as widely expanding technology in the Architecture Engineering, Construction and Operations (AECO) Industry aims integrating all aspects of building life cycle from conceptual design to demolition and deconstruction. BIM provides possibility of automating time planning (4D), cost estimation (5D) before the construction commencement, and time, cost management during construction. Though BIM adoption and implementation in the Republic of Armenia (RA) AECO Industry is going slowly, there are some developments that prove RA Government interest in BIM adoption for enhancing Industry efficiency and transparency. The research was focused on cost estimation automation and BIM integration issues in Armenia. For this the construction cost estimation backgrounds of a number of countries as Belarus, Italy, Kazakhstan, Kyrgyzstan, Russian Federation (RF) and USA were studied along with the practices of integration it with BIM technology. The results of the study were compared with the situation of cost estimation practices in the RA. The study reveals that for BIM technology and cost estimation incorporation, there are various barriers as local building codes, regulations, specifics of construction technologies, and common requirement of uniqueness for each erected building. As conclusion the author proposes further standardization of the Industry by developing construction elements’ reference books and databases for joint usage by designers, architects, building engineers and cost estimators for safeguarding future management of the quantity takeoff information.
Physical and chemical processes of volcanic rock hardening with alkaline silicates
Authors: Sahakyan Emma , Arzumanyan Artavazd , Muradyan Nelli 
Published: December 2019

Abstract
The thermodynamic probability of reactions in volcanic rock compositions — an alkaline silicate binder, which is used to produce artificial stone (concrete) products with high physical and mechanical properties and with wide range of colors for interior and exterior wall tiling and external masonry, manufacturing of decorative architectural details, etc. are considered. Silicate and aluminosilicate rocks of volcanic origin (perlite, pumice, tuff, etc.) of various deposits of Armenia are dispersed volcanic glasses with feldspar inclusions and are characterized by a large variety of colors: white, beige, yellow, orange, violet-pink, pinkish, red, brown, black, greenish, bluish-white, etc. Dolomite hardener is introduced into the composition for manufacturing of waterproof concrete on a base of a chemical binder at low temperatures.The possibility of reactions in a mixture of volcanic rock – alkaline silicate – dolomite – water was assessed by thermodynamic method. The calculation of Gibbs energy of the interaction reactions in the indicated system witnessed the possibility of realization of hydration, hydrolysis, silicate formation reactions even at a temperature of 298K.The formation of hydrated silicates and calcium and sodium aluminosilicates, guarantees the binding properties of the composition under normal conditions. With an increase of the temperature to 375, 475, 574K, the probability of reactions increases.