bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Deep Water Culture (DWC) hydroponic nutrient solution level control systems
Authors: Nursyahid A , Setyawan T A , Sa’diyah K , Wardihani E D , Helmy H , Hasan A 
Published: March 2021

Abstract
Hydroponics is the cultivation of plants that use water as a planting medium without using soil. One of the simplest hydroponics is Deep Water Culture (DWC). DWC is a hydroponic technique that allows plant roots to always be submerged in water containing nutrients. The purpose of the application of controlling the level of hydroponic nutrient solution in the type of Deep Water Culture (DWC) in the box is to ensure that the roots of the plant are always submerged in nutrient solution so that the nutrients are still fulfilled. The results obtained from controlling the level of hydroponic nutrient solution in the type of Deep Water Culture (DWC) in the box is when the level of nutrient solution is less than the specified threshold then the 12VDC pump relay will live to drain the source water to the nutrient solution reservoir. The HC-SR04 sensor is used for reading the level of nutrient solution, so it has an effect on determining the pump life time. The HC-SR04 sensor has a reading error of 0.87%. The duration of the pump life is determined based on the linear regression equation. Controlling the level of nutrient solution based on linear regression linear calculation has a good accuracy of 88.6%.
Biaxial pressure pack carburizing method to modification local low carbon steel’s mechanical properties
Authors: Satito A , Hariyanto H , Supandi S 
Published: March 2021

Abstract
The absolute requirement for steel material can be hardened directly is the carbon content of this material is more than or equals to 0.3 %. This steel material is recognized as medium carbon steel and above. Carburizing process is an effort to increase low carbon content in soft steel material which have less than 0.3 % it can be done by adding carbon content up to 0.3 % and above. The tool commonly used for this process called pack carburizing device and the process occur in furnace atmospheric pressure. In this research, carbon content adding process held on pressurized pack carburizing container, and the pressure was given mechanically from two axial direction named biaxial pressing carburizing process. The speciment material used in this research is local low carbon steel (ST.37) and coconut shell active charcoal powder. Process parameter The process parameter are pressure, temperature, and hoding time. The best result is achieving at a process temperature of 1000 ºC with 3 hour holding time and biaxial pressure of 2 MPa with 115.4 HRB, 823,6 N/mm2, and 0,41 % the incensement of carbon content from 0,27 % to 0,40 %.
Experimental study of transmission ratio changing mechanism for motorcycle applications
Authors: Supriyo B , Ariyono S , Sihono S , Sumiyarso B , Tjahyono B 
Published: March 2021

Abstract
Transmission ratio change in today’s motor cycle rubber belt Continuously Variable Transmission (CVT) are based on centrifugal forces resulted from engine revolution. Compare to manual transmission, this kind of CVT needs higher engine revolution to start engaging the transmision ratio which in turn requiring more fuel consumption. A transmission ratio change concept based on an Electro-mechanical actuator consisting of cam, actuator gears and DC motor has been developed to eliminate the dependancy of transmission ratio on engine revolution. The DC motor rotates the cam through actuator gears. The rotation of the cam causes the primary movable pulley sheave to move in axial direction, which in turn changing the belt-pulley pitch radius and changing the transmission ratio. This research aims to design and implement an electronic measurement system based on Arduino Uno as a data acquisition system and Matlab/Simulink as a controller program to obtain the measurement data of primary pulley and secondary pulley speeds and primary pulley axial position. Based on these data, the transmission ratio can be determined and the relationship between transmission ratio and primary pulley posistion can then be obtained. For future development, these measurement data will be used as important references when developing and testing the transmission ratio controller programs.
Participatory rural appraisal strategy in realizing the standardization of ship components
Authors: Khoryanton A , Pratikto P , Suparman S , Santoso P B 
Published: March 2021

AbstractThe role of ships for Indonesia is very important as a trigger for economic development and inter-island liaison. In line with the Indonesian government program in realizing the sea toll program and as the ruler of the world maritime axis, the ship needs will increase rapidly then the shipping industry becomes the main foundation in supporting this program. However, the development of the shipping industry in Indonesia is still hampered because ship components are still largely imported. As many as 70% of ship components must be imported from abroad. While many domestic SMEs of ship components have not been standardized, so they have not been able to support the shipping industry. The purpose of this study is to formulate participatory rural appraisal strategy in realizing the standardization of ship components. The results of the research indicate that there are five main factors influencing the success of product standardization: function and performance of Local Working Group Platform, the involvement of strong certification institutions, availability of technical expert and supporting institutions, shipyard in Evaluation Monitoring. The standardization program undertaken by SMEs of ship component is very important to support the shipping industry in Indonesia.
Optimization of 25-bar truss structure with the consideration of thermal expansion
Authors: Lin K H , Htet N L , Htike T M 
Published: March 2021

Abstract
This paper presents the change in the optimal cross-sectional areas of 25-bar truss structure due to thermal expansion. The 25-bar spatial truss is commonly used in structural engineering as a benchmark for structural optimization. Previous studies used different optimization methods to compute the optimal cross-sectional areas of the truss structures related to the minimal weight of each bar element. However, most of the previous studies conducted the optimization under mechanical load only and reported almost the same optimal areas and minimum weight with slight variations depending on the method used. However, very little has been done on the structural optimization with the consideration of thermal expansion. This study aimed to investigate the effect of thermal expansion in structural optimization and conducted optimization of this structure under the thermal load and the same mechanical load case with the previous studies. The difference in the optimal areas between with and without thermal expansion is analysed through optimization of both cases using MATLAB Optimization Toolbox. The optimization method used is fmincon with Sequential Quadratic Programming (SQP) . The result shows both an increase and decrease in optimal cross-sectional areas. The optimal weight of the structure increases by 12.26% at the surrounding temperature of 30°C. Therefore, this study highlights the needs of consideration of thermal load in optimizing the cross-sectional areas of the structure for minimum weight and this is particularly of important consideration in designing the truss structures in tropical climate. One of the limitations of this study that the SQP may not be appropriate for large structure and hence the robustness of the method should be tested with more variable.
Multidisciplinary design optimization for sustainable design using building information modeling
Authors: Tien Le Hung , Tung Nguyen Van 
Published: March 2021

Abstract
This paper illustrates the application of computational design using Rhinoceros software and Grasshopper plugin to investigate a real accommodation with respect to the solar radiation reduction. The paper also introduces the basic concepts of Building Information Modelling (BIM) utilization in construction. The multidisciplinary BIM model show that the Computable BIM Model can be used for Architecture, Structure, Mechanical - Electrical -Plumbing (MEP) to help architects, designers do sustainable design such as acoustic comfort, lighting design on effective cost manner with many rapid design options from the conceptual design phase, to facilitate wind load simulation, predict structural behaviour under fierce conditions, to estimate heat load, HVAC systems performance for energy saving and sustainable design.
Balancing control for single-wheel unicycle Robot using the Sliding mode controller
Authors: Nguyen P L , Nguyen T P , Ngo T M 
Published: March 2021

Abstract
In recent years, sliding mode control has been disseminated in the industry, including nonlinear control, and is considered as one of the simplest methods for nonlinear system control, including uncertainly model-based systems that are affected by external magnetic interference or parameter conversion. This paper shows the method of sliding mode control for a single-wheel unicycle-like mobile Robot. First, the Robot kinematics model was established by using a self-balancing system based on the balancing control principle in two models; flywheel inverted pendulum. In order to simplify the complicated problem with high nonlinearity, this model was balanced in each direction. Then the system model was emulated, showing the result that the separation sliding mode control worked properly with a large angle of deflection (0.17 rad), and the wheel rolled slowly with the relatively low speed (∼2.1 rad/s), while the flywheel rotated slowly with high-speed of rod control (∼28 rad/s).
Evaluation of action sport camera optical motion capture system for 3D gait analysis
Authors: Rizaldy N , Ferryanto F , Sugiharto A , Mahyuddin A I 
Published: March 2021

Abstract
The high price of motion capture systems on the market has been a hindrance for many hospitals, health agencies and rehabilitation centers to acquire them. Due to its significance in gait analysis, the ITB Biomechanics Research Team has developed affordable motion capture systems since 2008. The advent of Action Sport Cameras (ASC) provide an affordable and portable alternative to the available motion capture systems. Hence, this work investigated the relative accuracy of an ASC based motion capture system. The well-established Vicon V8 with 10 cameras system is utilized in this study to evaluate the proposed ASC Mocap system. Simultaneous gait data acquisition is necessary to ensure valid comparison. Evaluation of the ASC based system was carried out by comparing the spatio-temporal and kinematics parameters obtained with that obtained with Vicon. Based on the parameters obtained, the 4 GoPro Hero 5 cameras system developed by the ITB Biomechanics Team’s is deemed to be suitable to be used in Gait Analysis, especially the spatio-temporal parameters that closely match the Vicon results. For the kinematic parameters, the results obtained while qualitatively similar, in many cases differ in magnitudes. This problem is currently is still under investigation and will be reported in future works.
Enhancing induced flow rate through a solar chimney by a forced flow
Authors: Nguyen Y Q 
Published: March 2021

Abstract
Solar chimneys absorb solar radiation for natural ventilation or cooling of buildings. In typical solar chimneys, the air flow is induced by the thermal effect which causes pressure gradient inside the chimney to deviate from that of the ambient air. The induced flow is employed to ventilate the connected building naturally. In this study, we aimed to boost the induced flow rate through a typical solar chimney by a forced flow at the inlet of the air channel which is divided into two ports for the forced and the induced flows. The air flow and heat transfer were modeled with a Computational Fluid Dynamics (CFD) model with the ANSYS Fluent CFD code. Changing factors included the forced velocity, the dimensions of the inlet port for the forced air flow and the length of the partition between the ports of the naturally induced and forced air flows. It is seen that the forced flow significantly reduces the pressure in the air channel compared to that of a typical chimney; hence increasing the induced flow rate. The flow rate was significantly enhanced as the forced velocity was above 0.2 m/s; the area of the inlet port for the forced flow was 12.4% of the total inlet area; and the partition height was less than 5.0% of the total height of the air channel. In this configuration, the forced flow can be the waste exhaust air flow from other mechanical ventilation systems of the building. Therefore, no additional energy is required for this solution.
Design and performance analysis of 1KW ORC turboexpander with R245fa as working fluid
Authors: Bonar Asybel , Pasek Ari Darmawan , Burhannudin Harmen 
Published: March 2021

Abstract
Organic Rankine Cycle (ORC) is a reliable technology to utilize low and medium thermal energy and has been in development since the beginning of the 19th century and has rapid development in the last few decades. There are a couple of ways to optimize ORC. One of them is to develop an optimized turboexpander. This paper will explain in detail the preliminary and detailed design approach used to design turboexpander for 1kW ORC with R245fa as working fluid. The numerical simulation was performed using ANSYS CFX with turbulence model of Eddy Viscosity Reynold Shear Stress and Aungier Redlich-Kwong Equation of state to predict the material properties. A couple of adjustments had been made when deciding the rotor thickness and blade number, as the proposed method was not able to produce reasonable geometry. The CFD result of the preliminary design has 4.79% less efficiency and 22.7% less power produced than the 0D design. The off-design parameters of 16 Blade number, 20000 rpm, and mass flow of 0.32 kg/s able to produce power 1.38 kW with the efficiency of 76.44%
Power output and power coefficient calculations of a small HAWT with tubercles using Blade Element Momentum Theory
Authors: Damirez V , Augusto G 
Published: March 2021

Abstract
A 0.6 m diameter, three-bladed, untwisted, fixed-pitch, and small horizontal axis wind turbine with tubercles was analysed using the Blade Element Momentum (BEM) Theory. Calculation frameworks based from the Original BEM Theory, Wilson-Walker Method, Glauert’s Empirical Formula, and Buhl’s Theory were used in the prediction of the power output and power coefficient. Numerical results from the calculation frameworks were compared to the experimental data taken from the literature. The power output predicted by the Buhl’s Theory was the closest to the actual results. In the case of the power coefficient, the Wilson-Walker Method produced an almost equal prediction at λ=4.06, showing only a percentage difference of 0.47%. Results also showed that the power coefficient predicted by the four calculation frameworks were more accurate at higher tip speed ratios.
Software development for sustainable design in Vietnam: Ecosystem - An approach
Authors: Tien Le Hung 
Published: March 2021

Abstract
The needs for accurate energy consumption estimation in different design alternatives are essential for all projects. The demands to achieve sustainable design drive not only the efforts of a large number of researchers and organizations all over the world but also for designers in Vietnam, especially for building design in Vietnam, whereas the green constructions are growing rapidly. The developed software in the first stage helps the designers to quickly calculate and select the alternatives for green building design. This paper is carried out under the collaboration project between Van Lang University (VLU, Vietnam) and Carnegie Mellon University (CMU, USA) to develop a software for sustainable design, which focuses on energy consumption optimization. This software is the first project towards the full software development life cycle for green design in Vietnam.
Decomposition analysis of Japan’s CO2 emissions
Authors: Dela Vega J A , Gonzaga J A , Gan Lim L A , Lopez N S 
Published: March 2021

Abstract
Studies have been conducted to uncover the underlying factors of global CO2 emissions. One method to quantify the driving forces of carbon dioxide emissions is decomposition analysis. In this paper, the logarithmic mean Divisia index (LMDI) method was used to investigate the driving forces of carbon dioxide emissions in Japan for the period of 1990-2017. As one of the world’s leading economies, it also contributes one of the highest CO2 emissions globally. Results highlighted the flaw of energy structure as one major factor affecting CO2 emission intensity. Another notable finding is how the state of the economy played a pivotal role in the shift of carbon emission levels. Potential policy recommendations were also introduced to establish a better power structure for electricity generation in the country.
Strength and fire resistance characteristics of geopolymers synthesized from volcanic ash, red clay and waste pen shells
Authors: Kalaw Martin Ernesto , Adiarte Jose Mari , Cruz Richard dela , Martinez Kylie Mae , Vega Christian Adrian , Promentilla Michael Angelo 
Published: March 2021

Abstract
This study utilized volcanic ash and red clay, as well as calcined waste pen shell (Baluko) in the production of geopolymer-based materials. The geopolymers were formed by activating the mixture of these raw materials (as the alumina-silica rich materials) with activating solution of 12M NaOH/Na2SiO3 (w/w: 2.5:1). Two sample types, a cube type and a slab type, were used in the study in order to conform to test standards for compressive strength and fire resistance test. The cube type molds were for the compressive strength tests while the slab type was used for the fire resistance tests. Material testing such as Fourier Transform Infrared (FTIR) spectroscopy was used to analyze the chemical characteristics of both the raw materials and the geopolymer specimens. The mixture containing 45% volcanic ash- 45% red clay-10% calcined waste pen shell powder (by weight) was observed to have the highest compressive strength out of all the samples tested. The fire resistance of the geopolymers formed from a ternary mixture of 16% volcanic ash-66.67% red clay- 16% calcined waste pen shell powder (by weight) was also observed to be comparable to that of ordinary Portland Cement (OPC). Furthermore, the FTIR results of both raw materials and geopolymer showed evidence that geopolymerization occurred in the samples, indicating that the selected precursors are viable for use in the formation of geopolymers.
Modern methods of modifying the frictional state of the wheel-rail system
Authors: Antipin D Ya , Vorobiev V I , Shishkina O A , Bondarenko D A 
Published: March 2021

Abstract
The paper analyzes and provides a systematization of possible methods for increasing the coefficient of adhesion of locomotive wheels to rails. Ensuring a rational value of the friction coefficient at the point of contact between the wheel and the rail makes it possible to reduce the energy consumption for traction, significantly reduce the wear of the wheel and rail rolling surface when passing the curved sections of the railway track, and increase the smoothness of the carriage and its safety during braking. Two fundamentally different methods of improving the locomotive traction qualities have been established - by means of structural improvements of the carriage and a direct effect on the physicochemical properties of the wheel and rail contacting surfaces. Practical methods of increasing the value of the friction coefficient in the contact between the wheel and the rail which include the use of sand, materials of natural origin, abrasive magnetic powder, braking of moving wheels, mechanical cleaning of rails, chemical cleaning of rails, electric spark cleaning of rails, plasma cleaning of rails, cleaning with high-energy sources, cleaning with high-energy sources, transmission of electric current and magnetic flux in the contact zone, the use of various modifiers of friction surfaces, are considered in detail. Their main advantages and disadvantages are noted. It is established that when wheels friction is on rails, mechanical, electrical, vibration, thermal, chemical, and magnetic processes occur simultaneously. In view of this, the practical implementation of a multivariate analysis of the entire complex of these phenomena is in most cases impossible. In this connection, it is suggested to be limited to a small set of factors that could most fully characterize the tribological system under study and determine the basic requirements for the experimental and theoretical studies.
Factors affecting the tribotechnical properties of sintered materials
Authors: Cherney O T , Skachkova E G , Permovskiy A A , Smirnova Zh V , Kutepova L I 
Published: March 2021

Abstract
The article considers the issues of production of powder antifriction materials based on iron by methods of pressing and rolling powder mixtures. The analysis of influence of composition of materials, technological conditions of their production and other factors on the structure, mechanical and tribotechnical properties of powder sliding bearings was carried out. During the operation of the machine, its elements, subjected to various influences, change in state, size and properties. The effectiveness of developments in the field of tribotechnical materials is determined by the properties of these materials, as well as the speed and breadth of their industrial use. The effect of porosity of samples on their tribotechnical properties and hardness after sintering and additional heat treatment is studied. The results of tribotechnical tests of iron-copper-graphite sintered sulfided compositions, not alloyed and doped with phosphorus, as well as materials including additional lubricant components: graphite, molybdenum disulfide or calcium fluoride, are presented. On the basis of tests, it was found that in conditions of liquid friction, alloying with phosphorus has a decisive effect on increasing wear resistance, and without supplying lubricant to sintered samples with impregnated oil, wear is more than an order of magnitude higher compared to the conditions of liquid friction.
Calculation of shock absorber parameters of torsional vibrations of screw pumps’ rod string
Authors: Davydov A Yu , Petrov V A , Zaripova L M 
Published: March 2021

Abstract
Torsional vibrations of the rod string occur during the operation of surface-driven screw pumping units, which reduces the reliability of the units. It is proposed to include a torsional vibration damper in the rod string to maintain stability. The calculation of the parameters of the shock absorber is presented.
Determination of stripping zones and axle spacing between the cylinders in two-cylinder stripping reaper (header)
Authors: Sakharov V A , Kuvshinov A A 
Published: March 2021

Abstract
Stripping devices become an alternative to harvester-threshers in the harvesting season. The research objective is improvement of harvesting operations, including the introduction of the method of soya stripping. The research showed that the use of a single-cylinder stripping device was not optimal, for harvesting losses exceeded agricultural norms. It was decided to use a two-cylinder scheme. The implementation of this design solution reduced the grain loss rate, but still it was not enough to achieve compliance with the requirements of classical soybean harvesting. For high-quality soybean stripping, it is necessary to calculate the zones of stripping and axle spacing between the first and second stripping cylinders, as well as the profile of the stripping combs. Schemes presented are calculation of the stripping zones and determination of the axle spacing between the cylinders, taking into account their positional relationship in the stripping reaper.