Hydrocarbon-Impacted Soils Supported Mn for Organic Pollutant Oxidation

Hydrocarbon-impeded soil (HIS) is solid waste from spills or leaks during industrial activities that negatively impact the environment. This study aims to utilize HIS as catalyst support on MnO2 to degrade RhB (RhB) solution using Peroxymonosulfate (PMS) and to determine the optimum conditions for the catalyst to degrade RhB. The catalyst was synthesized by reacting HIS, calcined with KMnO4 with various catalyst supports with high and low Total contain Petroleum Hydrocarbon (TPH). The process degradation of Rhodamine Solution was carried out with various catalysts, PMS, and RhB concentrations. The catalyst was characterized using X-ray diffraction (XRD), Nitrogen gas adsorption-desorption (BET), and Scanning Electron Microscope-Energy Disperse Spectroscope (SEM-EDX). In this study,  the best catalyst performance was MnO2@H-TPH, which could activate PMS to degrade RhB with dye removal of 98% in about 180 min, at conditions 10 g/L RhB, 0.1 g/L catalyst, and 3 g/L PMS with the activation energy of 16.3 kJ/mol

Computational Fluid Dynamics Modeling of Fermentation Reactions in Bioethanol Fermentor: A Review

Bioethanol is a renewable energy source that can replace fossil fuels. The advantages in terms of economy and its impact on the environment make bioethanol was chosen as a biofuel. Bioethanol can be produced from various types of biomasses with the help of microorganisms, namely yeast, for the fermentation process. In manufacturing, factors including temperature, concentration, pH, fermentation time, and stirring speed influence the fermentation process. Computational Fluid dynamics (CFD) package can be applied to observe the procedures in a fermenter. CFD simulates fluid movement, energy transport, chemical reactions, and other phenomena with the aim of clarifying their impact on the overall effectiveness of bioethanol production. In this journal, a review of the fermentation process with CFD modeling was made to look at the parameters and phenomena during the bioethanol production process. The analysis commences with an examination of the processes involved in bioethanol production and underscores the crucial role of fermentation in transforming renewable resources into bioethanol. Subsequently, it delves into the foundational principles of CFD and how they are incorporated into the modeling of bioethanol fermenters. Furthermore, the review highlights key advancements and innovations in CFD modeling techniques, such as multiphase models, turbulence modeling, and coupled simulations, aiming to capture the intricate interplay of physical and biological phenomena within fermentors. Insights into the impact of operating conditions, reactor design, and microbial behavior on bioethanol yield and quality are discussed, providing a comprehensive understanding of the complex system dynamics

High-Performance Aqueous Electrolyte Symmetrical Supercapacitor using Porous Carbon Derived Cassava Peel Waste

Electrolytes have been generally recognized as one of the most important components in enhancing the electrochemical performance of supercapacitors. On the other hand, aqueous electrolytes are considered prime candidates for the development of the next generation of symmetric supercapacitors due to their low-cost, environmentally friendly, high ionic conductivity, fine ionic size, and high capacitance. Herein, the symmetrical supercapacitor of the sustainable porous carbon-based electrode material was confirmed through various aqueous electrolytes consisting of neutral, basic, and acidic Na2SO4, KOH, and H2SO4. Activated carbon is obtained from high potential biomass sources of cassava peel waste. Activated carbon synthesis was performed with a comprehensive approach in order to obtain abundant pore structure, high porosity, and improved wettability through a combination of high-temperature chemical and physical activation. in addition, the electrode material is designed to resemble a solid disc without the addition of a synthetic binder. The evaluation of the disc dimensions showed high porosity in the obtained activated carbon. Furthermore, the symmetrical supercapacitor of the optimized electrode material exhibit excellent specific capacitances of 112, 150, and 183 F g-1 at 1 mV s-1 in the electrolytes Na2SO4, KOH, and H2SO4, respectively. In addition, the highest rate capability of 70% was confirmed in the H2SO4 acid electrolyte. Moreover, their coulombic efficiency can be maintained around 89% with low equivalent series resistance 0.21-0.42 ?. Therefore, the activated carbon-based supercapacitor symmetric cell device from cassava peel shows high performance for developing high-performance supercapacitor applications with guaranteed stability in aqueous electrolytes

Speed Control of Three Phase Induction Motor using Space Vector Width Modulation (SVPWM) Technique with PI Controller

This article aimed to design and simulated the speed control of a three-phase induction motor using a PI controller with Space Vector Pulse width modulation technique. The induction motor  used in this article is was designed at the Electrical Energy Conversion Laboratory, Riau University, with a power of 1.1 kW, 380 V, 2-pole. Meanwhile, the PI controller constants used in designing this induction motor were determined using the Fine Tunning method to obtain KP and KI values of 3.539 and 9.526, respectively. The tests were carried out by running simulations in three conditions, namely no load, full load, and variable load at a speed of 2800 rpm. The test results showed that the use of a PI controller can improve the speed response of induction motors by eliminating the steady state error. This is in addition to increasing the rise time response of the motor speed by 0.012s and 0.046s at no load and full load, respectively, when the rise time analysis is at the same value. It can also accelerate the motor to reach a peak speed of 0.247 s and 0.166s at no load and full load. In addition, SPVWM with PI controller can maintain speed setting even though there is a load change during operation, which can be verified with load testing

Various Methods of Strengthening Reinforced Concrete Beam-Column Joint Subjected Earthquake-Type Loading Using Fibre-Reinforced Polymers: A Critical Review

Fibre-reinforced polymer (FRP) composites are extensively employed in concrete technology due to their exceptional mechanical strength and durability.  They serve a dual purpose, not only reinforcing damaged elements but also supporting heavier service loads and addressing long-term concerns in new infrastructure projects. Consequently, the objective of this review is to establish a comprehensive research database that focuses on evaluating the strengthening behaviour of reinforced concrete (RC) beam-column joints (BCJ) under earthquake loads through diverse types and application methods of FRP composites. The efficacy of these strengthening techniques is assessed by considering factors such as the loading capacity and dissipated energy of RC BCJ versus the joint confinement index provided by the fibre in the joint area. Through this state-of-the-art review, it becomes evident that FRP composites effectively enhanced the normalized load of specimens up to 27 kN/?MPa and enhanced the dissipated energy until 558.6 kN-mm for the case of specimens with a lower confinement index, less than 0.3. Additionally, the specimen strengthened with the deep embedment (DE) method resulted in a moderate normalized load and dissipated energy compared to those strengthened with the external bonded (EB) method. The test results indicated that the average normalized load and dissipated energy of the DE-strengthening method was 93% and 28.5% compared to that of the EB-strengthening method. These findings reveal that FRP composites offer distinct advantages in terms of load capacity and dissipated energy when used for strengthening earthquake-affected RC BCJ. Finally, based on the compilation of the previous works, this research proposes several techniques for utilizing FRP composites to enhance RC BCJ subjected to earthquake load

Energy Router Applications in the Electric Power System

Energy router is being investigated to replace conventional transformer in the electric grid. Improvement so far observed in use of converter makes possible the intelligent integration between systems with different characteristics’ in terms of frequency and voltage levels as well as exploitation of generation sources and storage systems typically operating in DC. Consequently, it is believed that Energy Router is able to interconnect different portions of electrical networks and at different voltage levels and types. The Energy Router is an assembly of converters isolated by a medium or high frequency transformer. In its design, different voltage levels and types are made available to achieve high results in terms of system integration, efficiency and flexibility. This paper evaluates the main potentials of this technology if widely introduced in the main power system. Starting from the single component description, a couple of possible applications are presented and discussed

Failure Analysis of High-Pressure Turbine Blades in Steam Power Plants

This paper describes the failure of high-pressure steam turbine blades. During the Serious Inspection, it was discovered that the ninth-stage high-pressure turbine blade had failed. The causes of blade failure are examined via visual inspection and destructive testing. The failure mechanism of the blades was determined by conducting mechanical properties testing, metallographic inspection, and energy spectrum analysis. The mechanical properties of the leaf and root blade specimens were within the range of blade steel for steam turbines according to the Chinese National Standard (GB/T 8732-2004), but the chemical composition was not identical. This is consistent with the root blade fracture pattern where the hardness value plotted from the test results is the lowest at the root blade location, which is the primary cause of fissure propagation

Improvements in Physical and Mechanical Properties of Asphalt by Addition of Low-cost Few-layers Graphene (FLG)

Physical and mechanical properties of asphalt have been improved by adding of few-layers graphene (FLG). FLG was obtained from a simple, low-cost and environmentally friendly liquid shear exfoliation method using a kitchen blender. The melted asphalt at temperature of 150oC was mixed with FLG at various concentrations (10 mg/ml, 20 mg/ml and 30 mg/ml) and contents (0 wt%, 3 wt%, 6 wt%, and 9 wt%) by weight of asphalt. The homogenized mixture was taken for penetration and softening point tests, while the mixing with aggregates was carried out for Marshall stability and asphalt concrete flow tests. The characteristics of void in mixture (VIM), void filled with asphalt (VFA), and void in mineral aggregate (VMA) were also investigated. The penetration values decreased (or the asphalt hardness increased) linearly with increasing of FLG concentration and FLG content. The softening point of asphalt increased as the increasing of FLG concentration and FLG content in asphalt with the average softening point increase of about 5%. The Marshall stability and asphalt concrete flow increased with increasing of FLG concentrations and FLG content. However, the addition of FLG did not affect the VIM, VFA or VMA values. Overall, the addition of FLG improves the physical and mechanical properties of asphalt and has promising prospects due to low-cost and eco-friendly nature of FLG

Peroxymonosulfate activation using CoFe2O4/Fe2O3 nanocomposite for Acid Orange removal

Herein, mixed–metal nanocomposite catalysts with various compositions (CoFe2O4/xFe2O3; x = 0, 0.25, 0.50, 0.75 and 1) were successfully fabricated by a co–precipitation method. The composition and morphology of the catalyst were systematically characterized. The catalyst with the highest Co content (CoFe2O4), exhibited the greatest efficiency for the acid orange 7 (AO7) degradation via peroxymonosulfate (PMS) activation. The effects of several experimental parameters including pH, CoFe2O4 loading, and PMS dosage on AO7 degradation were studied, and the catalytic activity was found to increase with the mentioned parameters. Moreover, CoFe2O4 displayed adequate reusability and was able to degrade AO7 for at least four consecutive cycles. In addition, the total organic carbon (TOC) removal of CoFe2O4 was determined while the catalyst stability was observed from the metal leaching in the treated solution. Furthermore, the magnetism of CoFe2O4 provides facile separation of the catalyst from the treated solution. Sulfate radicals (SO4•–) were identified as the main reactive species responsible for AO7 degradation

Development of Cork-Bamboo-Latex as An Alternative Composite for Bottles Stoppers

Agglomerated cork composites production has been arising as an alternative eco-friendly to cork stoppers use and attracts interest to create sustainable products and materials. A cork-bamboo-latex composite was developed by compression-molding and the interaction between three composite interfaces as well as their mechanical properties were evaluated by density measure, immersion test, FTIR, compression test, and microbial analysis aiming to produce an alternative material to wine closures. The results obtained were compared between the composite produced and the commercial agglomerated cork stoppers. It was possible to observe that the cork-bamboo-latex composite produced exhibited a good adhesion of all components and similar characteristics. However, it presented a slight increase in the density (from 0.37 g/cm3 to 0.65 g/cm3) and Young's modulus (from 0.033 MPa to 0.037 MPa) producing a stiffer material mainly due to bamboo presence. The migration of the stopper components (cork, bamboo, or latex) for the wine was not detected, as well as there was no visible interaction between wine and composite. In this work, the cork-bamboo-latex stopper fabricated presents a potential application as an alternative material to wine stoppers and stimulates the production of a sustainable material