Engineering (29) at IgMin Research

Many countries have used various strategies in the effort toward transition to alternative energy as a solution in developing renewable energy. Indonesia is the second largest producer of geothermal energy in the world. The potential of Indonesia lies in the Ring of Fire along with 117 active volcanoes, giving Indonesi...a high geothermal potential. This research aims to reveal and formulate the potential of geothermal as renewable energy in Indonesia as an alternative energy to be used in the future. The methods in this research are qualitative and quantitative. Through the quantitative method, this research will present secondary data from various organizations as well as data from prior research on geothermal potential in the world. While qualitative method will formulate ideas of several geothermal usages from many countries by using comparison from prior research and literature from journals, books, and other publication sources. Qualitative research results will also come from in-depth interviews with stakeholders that have implemented geothermal energy in Indonesia. The result of this research will illustrate the importance of geothermal energy as an alternative renewable energy in Indonesia to replace crude oil resources as the main natural resource in Indonesia. This research recommends the mapping of resources, requiring technology as a breakthrough in processing geothermal energy to take it directly from the reservoir because of its unorthodox classification based on its source as well the cost and benefit impact on the economy related to consumer mapping to detect early the market changes of energy to geothermal.Read more

The article presents a case study on the Investigation of lateral vibrations in the turbine-generator unit 5 of the Inga 2 hydroelectric power plant in the Democratic Republic of the Congo. Lateral vibrations were experimentally determined using twelve proximity and eddy-current probes, positioned on each measurement p...lane. The results were analyzed using the Dasylab and R software. Hence, it was observed that the vibration amplitudes of the upper guide bearing, lower guide bearing, and pivot/rotor exceeded acceptable or critical limit values of the international vibration standard for a rotating speed between 100-250 rpm. These excesses can lead to rotor mass imbalances, the eccentricity of the rotor axis relative to the rotation axis of the shaft, and the deformation of the coupling shaft between the upper rotor shaft and the turbine rotor shaft. Subsequently, the means and the variances of the vibration amplitudes were evaluated and compared to the reference values of the international standard. The results of the compliance analysis revealed statistically significant differences between the measured amplitudes and the reference values. Thus, it indicates deviations from international specifications.Read more

The article discusses the methods for determining the maturity of grain and describes its behavior during harvesting, to optimize the selection of the grain moisture state, discusses the requirements for the choice of measurement method and the design of moisture control measuring devices, as well as its high accuracy ...and the possibility of measuring from field conditions, collection, storage, transportation, and industrial processing and release of finished products of granular materials.The purpose of the study is to improve the efficiency of control and management of complex technological processes and moisture control devices for granular bulk materials of plant origin through the development of systems for automatic and automated control of the electrophysical characteristics of grain products and to increase the reliability of quantitative and qualitative assessments of production and technological measurement information. To achieve this goal, it is necessary to conduct analytical and experimental studies of the possibility of creating an express method for controlling the moisture content of grain and products of their industrial processing and the development of a moisture meter for automated control of raw material parameters during acceptance and storage at grain processing enterprises. The article discusses the scientific and methodological foundations for measuring the electrophysical characteristics of grain products of agricultural production and the implementation on this basis of the functional subsystem of information support by the Automated Process Control System for Controlling the Mass Ratio of Moisture of Plant Origin Materials. A critical analysis of the current state of the theory and practice of automatic control of electrophysical characteristics of grain products and the identification of the trend of their further development and improvement are carried out. A mathematical model of the interaction of a high-frequency field with a granular material has been constructed, where the influence of the elastic properties of the grain on the electrical characteristics of the electromagnetic wave, which distinguishes its behavior in the field of a high-frequency wave from many other dielectrics, has been substantiated, and the influence of a large number of various disturbing factors has been studied, often the measurement results cannot be applied in the control of the technological process due to the uneliminated error, which is the cause of inaccurate information. Primary measuring transducers of electrophysical parameters of grain products are proposed, and their mathematical models are considered. A functional scheme of the measuring device based on the dielcometric method of moisture control of grain and granular materials has been developed, and metrological characteristics have been given.Read more

Reconstruction of pulverized coal boilers BKZ (Barnaul Boiler Plant, steam productivity 160 t/h, pressure 100 kgf/cm2, fuel: natural gas/fuel oil) with steam productivity of 160 t/h, converted to gas combustion, and an increased load capacity to 210 t/h, has been carried out. As part of the boiler modernization, a chem...ical water treatment system was reconstructed, significantly improving the quality of feedwater: hardness not exceeding 0.3-0.5 µeq/kg; SiO2 not exceeding 18 µg/kg, and electrical conductivity Х=0.6-1.0 µS/cm. The previously used phosphate regime for boiler water was replaced with a chelant-based regimen using trilon B. During operation, widespread damage to the screen tubes occurred. Circulation tests were conducted on one of the boilers, and an analysis of internal deposits was performed.It was determined that water circulation in the side screen is stable, and its velocities correspond to calculated values. The main cause of metal ruptures in the screen tube is metal corrosion, as well as local overheating of the wall caused by the formation of a steam layer due to the detachment of internal deposits.Read more

Sri Lanka is facing an energy crisis due to insufficient exploitation of renewable energy resources and high reliance on imported fossil fuels. Building-integrated PV (BIPV) systems are one approach that provides various benefits in countries with limited land areas and congested metropolitan regions for ensuring energ...y security. This study was conducted to evaluate the rooftop solar PV capacity and yearly electricity generation potential in selected provinces in Sri Lanka. The study found 115 km2 of rooftop area for solar PV installation in four Sri Lankan provinces; Sabaragamuwa, Western, Northern, and North Central with approximately 25 GW of solar PV installation capacity could lead to annual electricity generation of 45 TWh which could reduce carbon emissions by 20 million tCO2 per year.Read more

The purpose of this article is to propose a model of an electric-fired brick oven, with the aim of eliminating the imperfections presented by traditional brick ovens. To complete this study, we used the concepts of heat transfer, and material resistance, as well as those of computer-aided mechanical design.Deemed satis...factory, the results found give a yield of 94.5% and a cooking time of 7.29 hours based on 2000 bricks cooked.Read more

The operating experience of mechanical seals shows that as a result of angular deformations of the rings, the wear of the contact surfaces along the radius is uneven. When designing mechanical seals, it is necessary to calculate the amount of expected leakage through the seal, friction power consumption, as well as the... possible durability of the unit. These calculated dependencies and estimates are obtained based on the constructed mechanical seal model. In the area of hydrodynamic load support in the case of a confusor joint or a converging film, the slope of the pressure diagram is such that a decrease in the film thickness increases the hydrodynamic support. This is referred to as enabling stable non-contact sealing operation. The execution of the rubbing surfaces of the interface of the end pair should ensure the formation of the calculated confusor shape of the sealing gap in all modes of operation and axisymmetric pressure fields during the rotation of the rotor.Read more

The governing equations for the shear stress corresponding to some magnetohydrodynamic (MHD) motions of a large class of rate-type fluids are brought to light. In rectangular domains, the governing equations of velocity and shear stress are identical as form. The provided governing equations can be used to solve motion... problems of such fluids when shear stress is prescribed on the boundary. For illustration, the motion in an infinite circular cylinder with shear stress on the boundary is discussed.Read more

This paper tackles the vital issue of missing value imputation in data preprocessing, where traditional techniques like zero, mean, and KNN imputation fall short in capturing intricate data relationships. This often results in suboptimal outcomes, and discarding records with missing values leads to significant informat...ion loss. Our innovative approach leverages advanced transformer models renowned for handling sequential data. The proposed predictive framework trains a transformer model to predict missing values, yielding a marked improvement in imputation accuracy. Comparative analysis against traditional methods—zero, mean, and KNN imputation—consistently favors our transformer model. Importantly, LSTM validation further underscores the superior performance of our approach. In hourly data, our model achieves a remarkable R2 score of 0.96, surpassing KNN imputation by 0.195. For daily data, the R2 score of 0.806 outperforms KNN imputation by 0.015 and exhibits a notable superiority of 0.25 over mean imputation. Additionally, in monthly data, the proposed model’s R2 score of 0.796 excels, showcasing a significant improvement of 0.1 over mean imputation. These compelling results highlight the proposed model’s ability to capture underlying patterns, offering valuable insights for enhancing missing values imputation in data analyses.Read more

The textile sector has great relevance in the Brazilian socioeconomic context, generating large volumes of effluents of varied composition, with dyes being one of the most worrying contaminants due to their characteristics of high solubility, harmfulness and low degradability. Among them the Reafix Yellow B8G (ARB8G) d...ye has an azo nature, harmful to organisms in the aquatic environment. According to Brazilian laws, it is recommended to dispose of waste through incineration or landfill, due to its resistance to biodegradation. One of the methods for treating effluents is the adsorption of contaminants using materials with adsorption capacity, such as residue from the burning of biomass in boilers (ash). The general objective of this work was to evaluate the adsorption kinetics by contact time of the ARB8G dye by boiler ash. The test was based on mixing the adsorbent material with a dye solution at 75 mg.L-1, at constant temperature and stirring at different time intervals. To quantify the amount of adsorbed dye, the UV-Vis spectrometry method was used. The kinetic test indicated an equilibrium time of 30 minutes, with 100% removal under the tested conditions. From this result and considering that boiler residue is an underutilized and low-cost material, it is concluded that this substance has significant potential to be applied as an alternative material for the treatment of effluents containing dyes.Read more

The article examines the priorities and prospects of the road map for the development of renewable energy using the example of Turkmenistan. The main scientific conditions of the goal, objectives, principles of public policy, a heterogeneous class of renewable technologies, the main scientific conditions of the road ma...p for sustainable development, the environmental aspect of climate change, mitigation potential, and costs are presented. The compiled roadmap for the use of renewable energy sources outlines the expected energy, economic, and environmental effects from the use of renewable energy technologies in remote areas from the centralized power line. The author believes that the outlined development roadmap for the use of renewable energy sources will become the basis for drawing up programs in other countries, depending on natural, climatic, and geographical conditions. Thus, the road map for the development of renewable energy sources, the use of local renewable energy resources, can reduce the need for fossil fuels in some cases by up to 80% and will significantly reduce the anthropogenic load on the environment. The introduction of renewable energy sources is one of the most relevant and promising for the development of the desert and the fight against desertification in the Karakum.Read more

The article obtained systematized, scientifically substantiated gross, technical, economic, and environmental energy resource potentials from the introduction and use of solar energy technologies. The technical, economic, and environmental priorities of power plants were assessed in terms of energy efficiency, fuel eco...nomy, and the environmental impact per square meter from conversion to thermal and electrical energy in the city of Arkadag.The calculated results are, kWh/m2 per year: gross resource potential of solar energy - 1844.6; the technical potential for conversion into thermal and electrical energy is equal to - 1256.44 and 242.44; economic - 502.6 and 96.98 kg fuel equivalent/m2 per year; environmental reduction in emissions of various harmful substances into the environment when using solar photovoltaic modules in the city of Arkadag will be: with annual electricity generation per m2 - 242.44 kW⋅h, annual fuel consumption savings - 96.96 kg. e., the reduction in emissions will be, kg per year: SO2 – 2.0; NOx – 1.1; CO – 0.14; CH4 – 0.29; CO2 – 155.0; solids – 0.21; when converted into thermal energy per m2 and annual production of 1256.4 kW⋅h, annual fuel savings are 502.6 kg of fuel equivalent; emission reduction will be, kg per year: SO2 – 10.4; NOx – 5.6; CO – 0.73; CH4 – 1.53; CO2 – 803.5; solids – 1.1.Empirical equations (1-5) have been obtained taking into account the gross, technical, economic, and environmental resource potentials of solar energy in the city of Arkadag, it is possible to carry out energy and environmental forecasting when drawing up a feasibility study.Read more

A new design of a fine positioner or high precision driven unit with a large positioning range is proposed for a custom-made in-situ indenter device equipped inside an SEM chamber. The design configuration of the proposed system is size-effective for the confined working area of the SEM chamber. The indentation depths ...can be precisely varied by controlling the fine positioner driven by a piezoelectric actuator. The main goal is to achieve very deep penetrations toward the bottom layers of tall or large-size scale specimens by single indentation, without the need for sequential indentations. Thus, the proposed design can eliminate the need for sequential adjustments of the specimen position with respect to the indenter tip as currently being practiced by the researchers. The specimen position adjustment after each indentation heavily depends on the coarse positioner and its accuracy level in a sub-millimeter regime which could result in position errors and unwanted lateral forces in the nanoindentation process. Therefore, the sequential indentations technique could lead to considerable variations in the outcomes of nanoindentation tests done on similar specimens. The proposed design will be realized to deploy in the Continuous Stiffness Measurement (CSM) techniques generally used to evaluate elastic properties as a function of continuous penetration depth with high-frequency loading and unloading cycles.Read more

All professional technical assessment processes are fraught with uncertainty. If a decision is premised upon the result, the decision maker must understand the reliability of the performed assessment. A causal theory application is developed utilizing distinct (linguistic, ordered) terms and continuous (numerical) vari...ables. It uncouples the methods from the result of the assessment obtained and focuses on those aspects that are important to the reliability assessment of the conclusion, not the answer itself. Matrices provide a means of characterizing the uncertainty of the methods and information available for each principal issue impacting the reliability. These matrices are determined as paired qualitative assessments of the Quality of the Measures Used and the Quality of Implementation of component description measures. Each is qualified by two to five grades, allowing three, five, seven, or nine quality distinctions for the assessed element. Uncertainty β values are determined for each component of the assessment combined by either an RMS procedure or a weighted average and converting a numerical value back to a consistent linguistic term. This procedure yields a basis for using good judgment while being sensible and reasonably cautious by independently determining the reliability using a carefully considered approach. California State University has assessed seismic retrofit priorities for 56 buildings using this method and has committed to its continuing use as its retrofit priority evaluation tool.Read more