A sudden pH drops always inhibits the anaerobic digestion (AD) reactor for biogas production from palm oil mill effluent (POME). The pH adjustment of POME by oil palm ash addition and the biogas effluent recycling effect on the preventing of pH drop and change of the archaea community was investigated. The pH adjustment of POME to 7.5 increased the methane yield two times more than raw POME (pH 4.3). The optimal dose for pH adjustment by oil palm ash addition was 5% w/v with a methane yield of 440 mL-CH4/gVS. The optimal dose for pH adjustment by biogas effluent recycling was 20% v/v with a methane yield of 351 mL-CH4/gVS. Methane production from POME in a continuous reactor with pH adjustment by 5% w/v oil palm ash and 20% v/v biogas effluent recycling was 19.1 ± 0.25 and 13.8 ± 0.3 m3 CH4/m3-POME, respectively. The pH adjustment by oil palm ash enhanced methane production for the long-term operation with the stability of pH, alkalinity, and archaea community. Oil palm ash increased t... [more]

A hexagonal boron nitride (h-BN) coating of micron thickness is deposited directly on 316L stainless steel (SS316L) cathode through efficient, adjustable electrophoretic deposition (EPD) in a suspension system containing surfactant and ethanol. It is based on the mixing of h-BN with polyethyleneimine (PEI) resulting in positively charged ceramic powder making cathodic electrophoretic deposition possible. The thickness of the resulting h-BN coatings deposited on SS316L could be controlled by varying the time and the voltage of electrophoretic deposition. The deposition kinetics and mechanism have been discussed. After soaking in Al(H2PO4)3 solution and high-temperature annealing, the h-BN coatings exhibited good adhesive strength. Furthermore, a novel method has been used for the evaluation of the adhesive strength to explore the appropriate experimental conditions. X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) a... [more]

This paper is divided into seven main parts. Its purpose is to review the literature to demonstrate the importance of developing bioengineering and global production of biomaterials to care for the level of healthcare in the world. First, the general description of health as a universal human value and assumptions of a long and healthy life policy is presented. The ethical aspects of the mission of medical doctors and dentists were emphasized. The coronavirus, COVID-19, pandemic has had a significant impact on health issues, determining the world’s health situation. The scope of the diseases is given, and specific methods of their prevention are discussed. The next part focuses on bioengineering issues, mainly medical engineering and dental engineering, and the need for doctors to use technical solutions supporting medicine and dentistry, taking into account the current stage Industry 4.0 of the industrial revolution. The concept of Dentistry 4.0 was generally presented, and a general... [more]

A new algorithm, Material Generation Algorithm (MGA), was developed and applied for the optimum design of engineering problems. Some advanced and basic aspects of material chemistry, specifically the configuration of chemical compounds and chemical reactions in producing new materials, are determined as inspirational concepts of the MGA. For numerical investigations purposes, 10 constrained optimization problems in different dimensions of 10, 30, 50, and 100, which have been benchmarked by the Competitions on Evolutionary Computation (CEC), are selected as test examples while 15 of the well-known engineering design problems are also determined to evaluate the overall performance of the proposed method. The best results of different classical and new metaheuristic optimization algorithms in dealing with the selected problems were taken from the recent literature for comparison with MGA. Additionally, the statistical values of the MGA algorithm, consisting of the mean, worst, and standar... [more]

Mangiferin (C19H18O11) is a C-glucoside xanthone that is mainly found in the leaves of mango (Mangifera indica L). The compound has been recognized for several pharmacological values, including antioxidant and antibacterial activities. Therefore, the present study aims to utilize the old leaves of mango as a potential source for mangiferin extraction and purification, and evaluate its antimicrobial and antioxidant properties. In the present study, mangiferin was extracted from a local variety of mango leaves using ultrasonic-assisted extraction methods and ethanol as the extraction solvent. The crude ethanolic extract of mangiferin was then purified by the liquid−liquid fractionation method with dichloromethane and ethyl acetate, then further separated by HPLC. The crude extract, ethyl acetate fractions and purified mangiferin were investigated for anti-microorganism activity against Escherichia coli, Salmonella spp. and Aspergillus flavus by using the paper disc diffusion assay. The r... [more]

In this study, a self-adjusting concentration of graphene thermal grease was developed to reduce the contact surface thermal resistance of 50 W light-emitting diodes (LEDs). The purpose was to identify an important type of heat conduction material with a high thermal conductivity coefficient, which can be applied to the contact surface of various high-heat sources or concentrated heat sources to achieve seamless heat transfer with an extremely low thermal resistance state. The contact heat conduction material conductivity reached the highest K value of 13.4 W/m·K with a 15 wt.% self-adjusting concentration of graphene grease. This material could continuously achieve a completely uniform and rapid thermal diffusion of heat energy. Therefore, we performed an analysis of chip-on-board light-emitting diodes (LEDs) with a highly concentrated heat source, which showed excellent heat dissipation under natural convection heat transfer. As such, this study achieved the natural convection mechan... [more]

Nowadays, in the beer sector, there is a wide range of products, which differ for the technologies adopted, raw materials used, and microorganisms involved in the fermentation processes. The quality of beer is directly related to the fermentation activity of yeasts that, in addition to the production of alcohol, synthesize various compounds that contribute to the definition of the compositional and organoleptic characteristics. The microbrewing phenomenon (craft revolution) and the growing demand for innovative and specialty beers has stimulated researchers and brewers to select new yeast strains possessing particular technological and metabolic characteristics. Up until a few years ago, the selection of starter yeasts used in brewing was exclusively carried out on strains belonging to the genus Saccharomyces. However, some non-Saccharomyces yeasts have a specific enzymatic activity that can help to typify the taste and beer aroma. These yeasts, used as a single or mixed starter with S... [more]

Insamyangpye decoction (ISYPD) is an oriental herbal prescription used in Korea to treat lung-related diseases such as chronic obstructive pulmonary disease. ISYPD is a complex prescription consisting of 13 herbal medicines, and ISYPD sample was obtained by adding 50 L of distilled water to a mixture (5 kg) of 13 herbal medicines, extracting at 100 °C for 2 h using an electric extractor, and freeze-drying. In this study, an accurate and sensitive liquid chromatography tandem mass spectrometry (LC−MS/MS) method based on multiple reaction monitoring (MRM) was developed and verified for quality assessment of ISYPD using 10 marker components: mulberroside A (1), amygdalin (2), liquiritin apioside (3), naringin (4), poncirin (5), platycodin D (6), ginsenoside Rb1 (7), glycyrrhizin (8), saikosaponin A (9), and schizandrin (10). These marker compounds were separated using an Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) maintained at 30 °C with a mobile phase elution gradient of aceton... [more]

An in situ emulsion polymerization method was used for the synthesis of polyacrylonitrile nanoparticles amino-functionalized partially reduced graphene oxide (PAN-PRGO). After that, hydrolyzed polyacrylonitrile nanoparticles amino-functionalized partially reduced graphene oxide (HPAN-PRGO) nanocomposite was achieved by the modification of nitrile groups of the composite polymer chains to carboxylic groups, aminoethylene diamine, and amidoxime functional groups through partial hydrolysis using a basic solution of sodium hydroxide for 20 min. Different synthesized materials were characterized and compared using well-known techniques including transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), Raman spectra, and X-ray diffraction (XRD). The nanocomposite was structured through the interaction between acrylonitrile’s (AN) nitrile groups and amino-functionalized graphene oxide nanosheets’ amino groups to successfully... [more]

The effects of high-basicity pellet on smelting chromium-bearing vanadia-titania magnetite are investigated via thermodynamic smelting and non-isothermal kinetics experiments. The thermodynamic results indicated that the high-basicity pellet significantly affects and ameliorates the softening-melting-dripping behaviors during the smelting process. As the high-basicity pellet ratio increased from 0 wt.% to 52 wt.%, the range of softening temperature [T40−T4] decreased from 121 °C to 84 °C and the melting-dripping temperature [Td−Ts] decreased from 224 °C to 169 °C. Moreover, the apparent activation energy of non-isothermal kinetics also decreased from 99.91 kJ·mol−1 to 66.74 kJ·mol−1. Additionally, the reaction mechanism of high-basicity pellet on smelting chromium-bearing vanadia-titania magnetite was investigated via thermodynamic calculations of Gibbs free energy and characterizations of the titanium slag. Therefore, combined with the lowest permeability index, the fastest non-isothe... [more]

Hydrophobic porous metallic membranes can be integrated in a microreactor for in situ separation of steam at high temperatures. This study investigates the fabrication and characterization of hydrophobic coatings on metallic substrates. Two different coating methods were explored: (1) Plasma Enhanced—Chemical Vapor Deposition (PE-CVD) to form amorphous carbon silicon-doped a-C:H:Si:O thin films and (2) Direct Immersion in fluoroalkyl silane (FAS-13) solution using dip coating to form Self-Assembled Monolayers. The results on wettability as well as SEM images and EDS/WDS analyses indicate that the coated sintered stainless steel membranes are adequate as hydrophobic surfaces, maintaining the porosity of the substrate and withstanding high temperatures. Especially the FAS-13 coating shows very good resistance to temperatures higher than 250 °C. These findings are of special significance for the fabrication of porous metal membranes for separation of steam in high temperature applications... [more]

The manufacturing process of robotic coreless filament winding has great potential for efficient material usage and automation for long-span lightweight construction applications. Design methods and quality control rely on an adequate digital representation of the fabrication parameters. The most influencing parameters are related to the resin impregnation of the fibers and the applied fiber tension during winding. The end-effector developed in this study allows efficient resin impregnation, which is controlled online by monitoring the induced fiber tension. The textile equipment was fully integrated into an upscaled nine-axis robotic winding setup. The cyber-physical fabrication method was verified with an application-oriented large-scale proof-of-concept demonstrator. From the subsequent analysis of the obtained datasets, a characteristic pattern in the winding process parameters was identified.

A variety of chemical sensing materials and procedures for conveniently detecting mercuric ion (II) (Hg2+) have been extensively explored. The detection challenges for accomplishing a simple, fast, and low investment procedure at the ultrasensitive level are ongoing. Herein we report a quadrillionth level for detecting Hg2+ by the surface-enhanced Raman scattering (SERS) technique. There is an interaction of silver nanoparticles decorated on a zinc-oxide tetrapod structure and coated on FTO glass (Ag@ZnO-FTO) with an organic ligand. 4,4′-Dipyridyl (DPy) performed as being chemisorbed by Ag nanoparticles interacting with a pyridine ring to produce plasmonic hot spots for SERS. The morphology of the surface and porous structure of the tetrapod becomes the powerful platform for enhanced SERS performance of DPy detection. In the absence of the augmentative electrolyte, the enhancement factor for DPy is more than 107. The inhibiting of the aggregation between Ag and DPy was present followin... [more]

This study aimed to prepare surface amino-riched passion fruit peel (DAPFP) by amination reaction with low-cost biomaterials and use it as a biosorbent to adsorb Cr (VI). The specific physicochemical and structural properties of DAPFP were characterized by SEM, EDS, XRD, TG, Zeta, XPS, and FT-IR. The effects of pH value, initial concentration, adsorption time, coexisting ions, and temperature on the adsorption of Cr (VI) were systematically investigated. The results showed that within 90 min, DAPFP could reduce the concentration of Cr (VI) solution (1 mg/L−1) to an allowable safe level of drinking water (0.05 mg/L−1) specified by the World Health Organization. The adsorption process complies with pseudo-second-order kinetics and the Langmuir isotherm model. The adsorption capacity of the prepared biosorbent could reach 675.65 mg/g−1. The results of thermodynamic studies confirmed that the adsorption process was a self-discharging heat process. DAPFP also showed good reusability; even a... [more]

plant offers a sustainable solution for the removal of various pollutants from water. Due to its chemical composition, Aloe vera has been explored as coagulant/flocculant and biosorbent for water treatment. Most of the used materials displayed significant pollutants removals depending on the used preparation methods. AV-based materials have been investigated and successfully used as coagulant/flocculant for water treatment at laboratory scale. Selected AV-based materials could reduce the solids (total suspended solids (TSS), suspended solids (SS), total dissolved solids (TDS), and dissolved solids (DS)), turbidity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), heavy metals, and color, with removal percentages varied depending on the coagulant/flocculant materials and on the wastewater characteristics. In the same context, AV materials can be used as biological flocculant for wastewater sludge treatment, allowing good solid−liquid separation and promoting sludge settlin... [more]

High doses of antimicrobial agents are a huge threat due to the increasing number of pathogenic organisms that are becoming resistant to antimicrobial agents. This resistance has led to a search for alternatives. Therefore, this study presents the synthesis and characterization of ZrO2-Ag2O nanoparticles (NPs) by sol-gel. The NPs were analyzed by dynamic light scattering (DLS), UV-visible (UV-vis), Raman and scanning electron microscopy (SEM). The NPs were later evaluated for their antifungal effects against Candidaalbicans, Candida dubliniensis, Candida glabrata, and Candida tropicalis, using disc diffusion and microdilution methods, followed by the viability study. The DLS showed sizes for ZrO2 76 nm, Ag2O 50 nm, and ZrO2-Ag2O samples between 14 and 42 nm. UV-vis shows an absorption peak at 300 nm for ZrO2 and a broadband for Ag2O NPs. Raman spectra were consistent with factor group analysis predictions. SEM showed spherically shaped NPs. The antifungal activity result suggested that... [more]

From the perspective of improving the thermodynamic properties of epoxy resin, it has become the focus of research to enhance the operational stability of GIS (Gas Insulated Substation) basin insulators for UHV (Ultra-High Voltage) equipment. In this paper, three aminosilane coupling agents with different chain lengths, (3-Aminopropyl)trimethoxysilane (KH550), Aminoethyl)-γ-aminopropyltrimethoxysilane (KH792) and 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TAPS), were used to modify nano-SiO2 and doped into epoxy resin, respectively, using a combination of experimental and molecular dynamics simulations. The experimental results showed that the surface-grafted KH792 model of nano-SiO2 exhibited the most significant improvement in thermal properties compared with the undoped nanoparticle model. The storage modulus increased by 276 MPa and the Tg increased by 61 K. The simulation results also showed that the mechanical properties of the nano-SiO2 surface-grafted KH792 mod... [more]

Cellulose is an important part of transformer insulation paper. Thermal aging of cellulose occurs in long-term operation of transformers, which deteriorates the mechanical properties and thermal stability of cellulose, resulting in a decrease in the transformer life. Therefore, improvement of the mechanical properties and thermal stability of cellulose has become a research hotspot. In this study, the effects of different silane coupling agents on the mechanical properties and thermal stability of modified cellulose were studied. The simulation results showed that the mechanical parameters of cellulose are only slightly improved by KH560 (γ-glycidyl ether oxypropyl trimethoxysilane) and KH570 (γ-methylacrylloxy propyl trimethoxy silane) modified nano-SiO2, while the mechanical parameters of cellulose are greatly improved by KH550 (γ-aminopropyl triethoxy silane) and KH792 (N-(2-aminoethyl)-3-amino propyl trimethoxy silane) modified nano-SiO2. The glass-transition temperature of the com... [more]

ReWaste4.0 is an innovative and cooperative K-Project in the period 2017−2021. Through ReWaste4.0 the transformation of the non-hazardous mixed municipal and commercial waste treatment industry towards a circular economy has started by investigating and applying the new approaches of the Industry 4.0. Vision of the ReWaste4.0 is, among others, the development of treatment plants for non-hazardous waste into a “Smart Waste Factory” in which a digital communication and interconnection between material quality and machine as well as plant performance is reached. After four years of research and development, various results have been gained and the present review article summarizes, links and discuss the outputs (especially from peer-reviewed papers) of seven sub-projects, in total, within the K-project and discusses the main findings and their relevance and importance for further development of the waste treatment sector. Results are allocated into three areas, namely: contaminants in mix... [more]

Poly(vinylidene fluoride) (PVDF) is a versatile thermoplastic fluoropolymer with intriguing characteristics, which is receiving considerable attention from researchers in many areas. Recently, PVDF and its copolymer, such as poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) have been blended with ionic liquids to produce blend and composite materials for target applications. In this succinct review, two types of ionic liquids that are utilized for the preparation of PVDF and PVDF-HFP blends and composites, namely, hydrophilic and hydrophobic imidazolium-based ionic liquids, are reviewed. In addition, the effect of the ionic liquids on the physicochemical properties of the PVDF and PVDF-HFP blends and composites, is described as well. On top of that, a multitude of applications of the blends and composites are also succinctly reviewed. This review may give inspirations to the polymer blend and composite researchers in diversifying the applications of thermoplastic fluoropolyme... [more]

In this study, we conducted an efficient microwave-assisted transesterification process combining homogeneous and heterogeneous catalytic phases to produce biodiesel from waste soybean oil. A cylindrical quartz reactor packed with nanoparticles of Fe3O4 as a co-catalyst was applied to improve the reaction. The process was carried out with a methanol-to-oil molar ratio of 6:1, power of 560 W, and residence time of 30 s. The specifications of the biodiesel produced in this study were compared with two standards, i.e., ASTM D6751 and EN 14214. We found that the continuous conversion of waste soybean oil to methyl ester was approximately 95%. The biodiesel showed a higher flash point and a higher carbon residue content than that of both standards, and the viscosity (5.356 mm2/s) and density (898.1 kg/m3) were both at a high level. Compared to a conventional heating plate, the energy consumption was significantly reduced by nearly 93%. It is expected that these findings will provide useful... [more]

Injection of Newtonian fluids to displace pseudoplastic and dilatant fluids, governed by the power-law viscosity relationship, is common in many industrial processes. In these applications, changing the viscosity of the displaced fluid through velocity alteration can regulate interfacial instabilities, displacement efficiency, the thickness of the static wall layer, and the injected fluid’s tendency to move toward particular parts of the channel. The dynamic behavior of the fluid−fluid interface in the case of immiscibility is highly complicated and complex. In this study, a code was developed that utilizes a multi-component model of the lattice Boltzmann method to decrease the computational cost and accurately model these problems. Accordingly, a 2D inclined channel, filled with a stagnant incompressible Newtonian fluid in the initial section followed by a power-law material, was modeled for numerous scenarios. In conclusion, the results indicate that reducing the power-law index can... [more]

Development and adoption of more efficient and robust technologies for reuse of wastewater embedded resources, in particular materials and energy, is becoming an unavoidable necessity. Among many emerging technologies in the sector of wastewater treatment residuals valorization, Pulsed Electric Field (PEF) processes have shown interesting potential, although they have not yet entered the sector’s mainstream as a consolidated commercial technology, as in other industrial applications, such as the food, medical, and bio-based industries. PEF is a non-thermal technology suitable to biological applications, involving gentle cell disintegration and enhanced cell membrane permeability and as such applicable to disinfection, sterilization, and to those processes that benefit from an enhanced extraction of organic compounds from biological matter, such as anaerobic digestion, biological processes for recovery of nutrients, and biorefinery of cell-embedded compounds. PEF technology applications... [more]

Different types of fabrics, such as aramid (A), carbon (C), basalt (B), glass (G), and flax (F), as well as powder fillers, were used to manufacture the epoxy-based hybrid composites by the hand-lay-up method. In this work, a few research methods, including hardness, flexural tests, puncture impact behavior, as well as cone calorimetry (CC) measurements, were applied to determine the impact of type fillers and order of fabrics on the performance and burning behavior of hybrid composites. The mechanical properties were evaluated to correlate with the microstructure and consider together with thermogravimetric analysis (TGA) data.

Water bodies and aquatic ecosystems are threatened by discharges of industrial waters. Ecotoxicological effects of components occurring in untreated and treated wastewaters are often not considered. The use of a linear, multi-compartmented, non-forced, static system constructed with PET bottles is proposed for the quality assessment of treated waters, to deal with such limitations. Two synthetic waters, one simulating wastewater from the textile industry and the other one simulating wastewater from the cassava starch industry, were prepared and treated by homogeneous Fenton process and heterogeneous photocatalysis, respectively. Untreated and treated synthetic waters and their dilutions were placed into compartments of the non-forced exposure system, in which zebrafish (Danio rerio), the indicator organism, could select the environment of its preference. Basic physical−chemical and chemical parameters of untreated and treated synthetic waters were measured. The preference and avoidance... [more]