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.

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.

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 150^oC 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.

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.

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 K_P and K_I 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.