bluuebunny/crossref_metadata_2025 huggingface dataset:
Photocatalytic Decolorization Simulated Textile Dyebath Effluent under Solar Light and Reuse it for Industrial Propose
Authors: Al-Azawiey Sundus S , Dakhel Ihsan Habeb , Naser Ghaze Fasil , Ali Ahmed Hasan
Published: March 2021

In this work, the photocatalytic is related to simulated wastewater as well as recycling for industrial uses. Photocatalytic degradation of simulated wastewater content (Eosin Yellowish, Eriochrom Black T, Methyl Violet, EDTA, FeSO4.7H2O, NaCl, and NaOH) was utilized as a treatment approach in batch reactors within solar light in a heterogeneous slurry with the use of many concentrations regarding the commercial powder ZnO as photocatalysts semiconductors. We have tested many operation conditions like (catalyst concentration, pH, initial dye concentration and final water treated properties). The water quality related to treated wastewater is based on the nature of waste added during usage, the industrial water supply quality, and the treatment degree which is received via wastewater. After that, the quality data of wastewater is evaluated and indicated at waste-water treatment plant majorly for the disposal of the treated effluents or discharge requirements with regard to gross pollution parameter.
Flexural Behaviour of Hollow Reinforced Concrete T-Beams
Authors: Abdulhusain Haider M. , Ismael Murtada A.
Published: March 2021

Hollow reinforced concrete Tee beam (HRCTB) is a beam that has longitudinal cavities that can be made usually by placing recycled plastic pipes in the web of beam within the tension zone. These cavities are used to pass electrical and mechanical equipment as well as the economic and sustainable benefits coming from subtraction some amount of concrete from these beams. This study tries to investigate experimentally the effect of circular cavities depth and its geometrical shape on the flexural behaviour of hollow reinforced concrete Tee beams. The experimental program comprises constructing and testing seven reinforced concrete Tee beams that have total height of 300 mm, flange width of 250 mm, flange depth of 75 mm as well as web width of 150 mm with beam length of 2000 mm. The first specimen is solid specimen while the others are divided into two groups, the first group consists of three specimens that have different longitudinal cavities depth which are 105 mm, 170 mm and 235 mm measured from top fibre of beam, and the second group includes three specimens that have different geometrical shape which are sharp parabolic (diameters are 35 mm by 65 mm), normal parabolic (diameters are 40 mm by 60 mm) and circular cavity of 50 mm diameter respectively. The results showed that increasing cavities depth from 105 to 170 and 235 mm from the top fibre of beam reduced the relevant first crack load by 3.57 %, 7.14 % and 17.86 % respectively and reduced ultimate strength by 0.39 %, 1.03 %, and 2.31 % respectively. In addition, the results revealed that the first crack load decreased by 3.57 %, 7.14 % and 7.14 % and ultimate load strength decreased by 0.26 %, 0.39 % and 1.03 % respectively for sharp parabolic, normal parabolic and circular specimen respectively.
Well-Organized Complexities: A New Theory of Life
Authors: Al-Guesbi Hassan A.
Published: March 2021

Unfortunately, humanizing nature becomes the dilemma instead of the solution. Imposing improper man-made systems on existing realms would destroy them. Mostly, they failed to respond and coexist effectively with their surroundings. In fact, they need both, adaptive and survived qualities to compromise between inner self-organizing and outer space-occupying structures together. The degrees of adaptively organized-complexities, emergent self-preserving structures, are presented and estimated by unique adaptive dimensions (DA). In addition, other different dimensions (called survived dimensions/DS
) are produced to measure the degrees of survivably organized-complexities and their evolving self-maintaining structures. Anti-patterns appear because of deliberated destructions that need to be repaired and ignorant interruptions that need to be completed. Hence, properly fixed and continually guided anti-patterns could be livable again accordingly. It is claimed that living patterns of healthy systems have well-organized complexities that can be detected, estimated and explained by new living dimensions (DL). They are sensitive parameters of wholeness as indicators of life. LAS (DL=DA/DS) is presented as a new formula to estimate living dimensions of (2D) systems according to their adaptive and survived dimensions. It is concluded that livable systems have specific living dimensions that approach to (DL≈1). Also, sustained systems have equivalent values of (DL≈DA≈DS≈1). Accordingly, it is possible now to recognize, trace and create optimal well-organized, coherent and livable systems. On the urban levels, these new findings open the way ahead to diagnose, treat and cure different unhealthy or inefficient performances of architectural and urban systems by optimal interventions. More different (2D) and (3D) ill-diagnosed systems would be of future hopeful investigations and researches.
A Novel Hybrid PV/T System for Sustainable Production of Distillate Water from the Cooling of the PV Module
Authors: Abed Angham Fadil , Hachim Dhafeer Manee , Najim Saleh E
Published: March 2021

A large portion of incident solar radiation on photovoltaic (PV) panels is transformed into heat; thus, reducing photovoltaic panel power. The photovoltaic module’s efficiency depends primarily on the ambient temperature, the temperature of the module, the incoming intensity of the solar radiation, and the composition of the PV material. Depending on the type of solar cells used, PV panel efficiency typically drops by 0.5 for each degree rise in temperature. The cooling technique is also beneficial to maintain the cell at the operating temperature and should be such that, with a uniform distribution, it holds the average cell temperature to its minimum values. The supply of drinking water is increasingly declining with increasing population, growth, and environmental pollution. Therefore, it is appropriate to concentrate on available distilling water. Due to its low cost, energy, and ability requirements, solar still is one of the promising technologies available for water purification. The current work attempts numerically to suggest and analyze the production of distilled water, electric power, and heating water for domestic by utilizing a simple passive cooling technique for a new hybrid PV/T. The present work benefits from the unwilled heat of PV panel to obtain freshwater without the construction of solar still by putting a glass cover on the original frame of PV. The system’s performance is investigated from various aspects such as distilled water yield, production of electrical and thermal power instantaneously, and daily by considering three types of mass flow rate in inner wick and four types in the outer wick. Results show that the mass flow rate of inner wick does not significantly affect the temperature of PV and distilled water yield, but the mass flow rate in outer wick has affected distilling water. The production of water was maximum for the CPVWD module and is increased by about 65.73% more than that for the PVWD. The CPVWD module is found to display the highest electrical efficiency while the PVWD shows the lowest value. Good agreement between the present results and previous works was found.
Strengthening of Reinforced Concrete Stepped Beam Using Cotton Belt (New Technique)
Authors: Alhussein Zahraa Abd , Jaafer Abdulkhaliq A
Published: March 2021

The stepped beam is a type of non-prismatic beams that extend the stepped joint by stress collection and require adequate detail for this joint to prevent early failure. This research demonstrates an experimental study aimed at the behaviour of reinforced concrete stepped beams. The status issue is the premature failure of the stepped joint. The experimental program consists of eight concrete beams. All beams are tested under a four-point load. Three variables are studied in this work, the first of which is compressive strength, which is normal strength of 40 MPa and high strength of 80 MPa. The second variable is the details of the steel reinforcement at the stepped joint and the third variable is the strengthening with a cotton belt. Models achieved increases ranging from (26.3-37.4) kN, (1.88-3.95) mm, and (31.75-116.882) kN.mm in the ultimate capacity, deflection, and energy absorption respectively. Whereas it showed a decrease ranging (14.38-27.68) in the initial stiffness for the compression strength variable. As for the rebar detail variable, it showed an increase ranging between (39-138) kN, (7.5-28.29) mm, (244-3099.619) kN.mm, and (22.285-31.425) kN/mm, for the maximum load, deflection, energy absorption, and initial stiffness, respectively. On the other hand, the strengthened beams achieved an increase in the maximum load by 120% with a slight decrease in stiffness by 3.5% concerning an unstrengthened beam.
Mechanical Properties of Porcelain-CaSiO3 Biocomposites Prepared by Sol-Gel Method for Dental Application
Authors: Abed I J , Abbas R R , Hamza A M
Published: March 2021

In this study, improving the mechanical properties of Porcelain-CaSiO3 bioactive composites has been investigated by X-ray diffraction (XRD), flexural strength, and Vickers microhardness tester. Preparing the porcelain-CaSiO3 composite has been done using the sol-gel method from Si(OC2H5)4, Ca (NO3)2.4H2O as starting materials and HNO3 used as a catalyst and mixed the sol of CaSiO3 with Porcelain IPS inline powder with three different weight percentages of CaSiO3 (P90CS10, P80CS20 and P70CS30 wt. %). Structural characterization revealed the amorphous phase of CaSiO3 when heated at 700 °C and phase transition to the crystalline phase when heated at 950 °C, where pseudowollastonite (α-CaSiO3) and Ca2(SiO4) phases have appeared. Concerning the mechanical properties, flexural strength, and Vickers microhardness for porcelain-CaSiO3 composites were increased with increasing CaSiO3 content in the composites. The maximum values of flexural strength and Vicker microhardness were recorded at P70CS30, and they were 99.85 MPa and 1604 MPa, respectively.
Chemical Inhibition for Steel Corrosion in Succinic acid at Different Temperature
Authors: Assi Abdullah Dhayea , Al-Alawy Ramy Mohamed Jebir
Published: March 2021

The steel infrastructure is continuously under corrosive attack in most environmental and industrial conditions. There is an ongoing search for environmentally friendly, highly effective inhibitor compounds that can provide a protective action in situations ranging from the marine environment to oil and gas pipelines. The corrosion inhibition of transmission steel in 1M HCl cell in the presence of succinic acid at temperatures (20,30,40,50 and 60) °C at concentrations within the range (10−6- 10−4) M for two hours using the weight loss method (WLM). The results showed that the inhibition efficiency increases with increasing inhibitor concentration and increases with temperature up to 60°C. The activation significance of the corrosion rates was calculated as the activation energy Ea, the change of the activation entropy ΔH, and the change in the activation entropy ΔS. Also, results show that the inhibition efficiency was increased with the increase of inhibitor concentration and increased with the increase of temperature up to 60°C. Activation parameters of the corrosion process include activation energies (Ea), activation enthalpies (ΔH), and activation entropies (ΔS). The results also showed that the adsorption of the inhibitor is subjected to the Langmuir law, and the maximum efficiency reached approximately 97% at 60°C in the 10−4M inhibitor concentration.
External strengthening of reinforced concrete beams with strand without stressing under flexural loading
Authors: Iswanto I , Oesman M , Mujiman M
Published: March 2021

This research was purposed to study the composite behavior and the increased capacity of reinforced concrete beam strength under flexural loading caused by external strand strength without stressing. The specimen is divided into 2 types. Type-I specimen has (150 x 300 x 3200) mm dimension with center point loading, and distance of strand clamp as (Ubars) variable; whereas, the Type-II specimen has (200 x 300 x 3200) mm dimension with third point loading, and the number of strand as variable. The test is carried out by static-monotonic loading, and displacement control. Experimental test results shows that the addition of strand on the lower surface of the beam increase the beam’s load capacity. However, the use of U- bars affects the stability of the concrete. The tighter distance of the U-bars decrease the capacity of the strengthening occured. The increased load capacity of Type I specimens, S3-150, S5-150 and S9-150 are 33.2%, 17%, and 12.1% against control beam (BK-150), respectively. Whereas, the increased capacity of the type-II beam strength of test specimens B1-200 and B2-200 are 10% and 17% against control beam (BN-200), respectively. And the increase of initial stiffness of beam Type-I test specimen S3-150, S5-150, and S9-150 are 14%, 18% and 5% against control beam (BK-150), respectively. Meanwhile, the increase of initial stiffness of Type-II beam of test specimens B1-200 and B2-200 are 21% and 24% against control beam (BN-200), respectively. This study shows that concrete and strand bonding is not compatible. The concrete has been reaching the limit strain, as well as the steel reinforcement in the concrete has been in yielded; meanwhile, strand that has fy is much higher than fy of reinforced steel, is still in elastic condition.
Mapping of flood-prone-zone and puddle-prone-zone in Cimahi city, West Java province
Authors: Karnisah I , Astor Y
Published: March 2021

Climate change and advanced urbanization level followed by the changing function of an area affect to the amount of water absorption area. It causes puddle and flood in city, include Cimahi, West Java, which is in the last 10 years has been surrounded by flood and puddle. To avoid the flood case in Cimahi, the re-identification and flood-factor inventory are needed. The identification and inventory are using the simplest method (literary study from any source), start from discussing session with Cimahi government, interviewing and filling questioner to the citizen who live in flood and puddle area, measuring river and drainage profile, counting the capacity of river and drainage, until simulating the 2-dimension and 3-dimension of flood and puddle. The result of the identification and inventory is shown in Flood-Prone-Zone Map and Puddle-Prone-Zone Map. According to Cimahi’s Flood-Prone-Zone Map, it shows that the flood-safe area is about 110,747 ha (2,70%), the not-flood-prone area is about 494,233 ha (12,05%), the flood-prone area is about 2016,474ha (49,18%), and the very-flood-prone area is about 1478,799 ha (36,07%). According to Cimahi’s Puddle-Prone-Zone Map, it shows that the puddle-safe area is about 128,616 ha (3,14%), the not-puddle-prone area is about 551,246 ha (13,44%), the puddle prone area is about 2702,826 ha (65,92%), and the very-puddle prone area is about 717,556 ha (17,50%). The Flood-Prone-Zone Map and the Puddle-Prone-Zone Map can be used as a reference for the Cimahi Government in formulating the policy of regional development.
Speed control system in mobile robot based on Bezier curve trajectory
Authors: Alfatih M F , Riyadi M A , Setiawan I
Published: March 2021

The development of robot technology is currently growing rapidly. Mobile robot is one robot with many applications in everyday life. One of the important things in the field of mobile robots is the problem of trajectories or trajectories, in this case how robots can track approved paths. In this study, the mobile robot control system has been tested to track tracks. The path used in this study is the third-order Bezier Order, with control points and end points of the predetermined pathway. Based on the results of simulation tests on the development of mobile robot trajectories, based on the results of simulation tests on mobile robots, it is found that the performance of the track tracking control system is very dependent on the placement of the Bezier curve control points or in other words the actual path formed by the robot is greatly influenced by the shape of the Bezier trajectory that was designed.
Bandwidth constrained distributed estimation for wireless sensor networks
Authors: Wardihani E D , Suharjono A , Sayekti I
Published: March 2021

The focus of this paper is power constrained in wireless sensor networks. We purpose an adaptive transmit power levels based on sensors noise variance and channel conditions. We also investigate its impact on energy saving. First, the measurement results of the sensors are quantized into discrete messages. Second, the quantized data are transmitted to the fusion center where a final estimate is generated. The optimal transmit power levels for each sensor is determined by the sensor noise levels and channels conditions from sensor to the fusion center. The goal is minimized the total transmitting power, while ensuring a given Mean Squared Error (MSE) performance. The sensor will be active when the measurement results of the sensors have low noises variances and the condition of the channel between the sensor and the FC is good and if the conditions are otherwise the sensor is not active with the aim of saving power. For the remaining active sensors, their optimal transmit power levels are determined jointly by individual channels gain, local observation noise variance sensor and the targeted MSE performance. Numerical examples show that an adaptive power levels achieves significantly smaller MSE than uniform power levels for the same average power consumption.
Web-based rule-based expert system to screen postpartum depression
Authors: Mufidati D , Widyawati M N , Suryono S
Published: March 2021

The high prevalence of postpartum depression significantly increases maternal morbidity. Lack of diagnosis for postpartum depression results in mothers missing early treatment necessary. The traditional screening method using questionnaire presents its own disadvantage in diagnosis. Therefore, development of postpartum screening method that focuses on ease in implementation is very much needed to improve postpartum maternal health. This paper proposes a screening information system for postpartum depression to help its proper treatment. This research employed the rule-based method to diagnose postpartum depression and the expert system to input symptoms data that will result in diagnoses. Respondents input symptoms data to be diagnosed by the system. The system then automatically generate output of suggested treatment based on expert input associated with the diagnoses the system is working on. This research employed the Randomized Control Trial method with Control Group Pre and Post Tests Design. Samples of this research were 52 postpartum mothers consisting of 26 respondents in the system group, and the other 26 in the manual group. Results show that 42.31% (n=11) of mothers suffer from postpartum depression. There is a significant difference in EPDS score prior to and after the use of the information system (P=0.000). The system also successfully generated very high TAM score, meaning that it is capable of postpartum screening along with ease of use and some other advantages. Therefore, screening for postpartum depression using information system is very effective and ensures proper and timely treatment.
Accelerometer sensor data analysis of bridge structural health monitoring system
Authors: Hapsari A A , Supriyanto E , Hasan A , Suharjono A
Published: March 2021

The use of Wireless Sensor Network (WSN) for monitoring systems continues to grow, as it is required data analysis of a sensor node in which there is an accelerometer, use WSN system intended for structural health monitoring application. This monitoring system prototype, built by integrating software and hardware with device microcontroller and sensor. The node sensor produces data and processed with a microcontroller, the resulting data is then immediately transmitted to the cloud by internet network using MQTT. The system was built with a firmware-based Internet of Things (IoT) and this verified using accelerometer sensor node. The data has also been explored and analyzed in the time domain and frequency domain using FFT. Using MQTT, data can be sent directly to the internet in the form of raw data or graph data over time. And in this paper authors do an analysis of the raw data of the output sensor accelerometer ADXL345 and applied to monitor the bridge. From experiments, conducted output accelerometer sensor can vary depending on the sensitivity of the values.
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

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

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

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

The 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Planning model of a group UAV flight in three-dimensional space
Authors: Maksimov N A , Zhigalov K , Gorban A V , Ignatev I V
Published: March 2021

The paper describes the algorithm and model for planning group actions of unmanned aerial vehicles (UAVs) to monitor a given set of objects. A distinctive feature of the task is the shooting of objects from a predetermined height. This makes it necessary to move from considering a “flat” model to planning a flight in three-dimensional space. In addition, the authors take into account the possibility of destroying individual UAVs and the need to reschedule the flight route for the remaining UAVs in order to accomplish the assigned task.
Use of criticality principle in information protection systems at machine-building enterprises
Authors: Zhigalov K Yu , Turluyev R R , Dudareva O V
Published: March 2021

At present, the security of information systems plays a key role not only for large enterprises, but also for individuals. The information presented in the paper considers an innovative approach to the organization of multi-stage protection of information networks based on access matrices created and specified by data on the degree of criticality of protected files against illegal actions of third parties. The authors proposed to use several levels of criticality with three degrees: critical for program running; important for programs; not critical to programs. Besides, an algorithm for determining the criticality level by file extension as universal is proposed as the basic one. Timely response to changes in critical files not only of the operating system, but also of all programs significantly increases the security of enterprise systems. Moreover, the proposed method can be used to minimize the loss of important data.
Influence of plasma arc power on the melting of the envelope layer containing NiCrBSi alloy and the surface coating quality during plasma heating
Authors: Nguyen Van Chie , Balanovskiy A E , Kargapol’tsev S K , Gozbenko V E , Karlina Yu I , Shtayger M G , Karlina A I
Published: March 2021

The experiments are carried out to obtain coatings by plasma heating of an envelope containing a NiCrBSi alloy with different thicknesses (0.25; 0.5; 1.00 mm) on exposure to different powers (100; 140; 160 A). The resulting coatings have different depths of the hardened layer. With a thin preliminary envelope layer (0.25 and 0.5 mm), defects easily appear under the influence of high power. With a thicker envelope layer (1 mm), the ability of the alloy to diffuse into steel is limited. The low power of the plasma arc of 100 A limits the diffusion and transformation of the molten pool, sufficient for saturation with alloying elements of a thick layer of the envelope (0.5 and 1 mm).