The kinetics and performance of a biological activated carbon (BAC) reactor were evaluated to validate the proposed kinetic model. The Freundlich adsorption capacity (Ka) and adsorption intensity constants (n) obtained from the batch experiments were 1.023 ± 0.134 (mg/g) (L/mg)1/n and 2.036 ± 0.785, respectively. The effective diffusivity (Ds) of the substrate within the activated carbon was determined by comparing the adsorption model value with the experimental data to find the best fit value (4.3 × 10−4 cm2/d). The batch tests revealed that the yield coefficient (Y) was 0.18 mg VSS/mg COD. Monod and Haldane kinetics were applied to fit the experimental data and determine the biokinetic constants, such as the maximum specific utilization rate (k), half-saturation constant (K), inhibition constant (Ki), and biomass death rate coefficient (kd). The results revealed that the Haldane kinetics fit the experimental data better than the Monod kinetics. The values of k, KS, Ki, and kd were 3... [more]

Interest has grown regarding natural plant extracts in food and beverage applications, their vital role in food quality and technology, and their therapeutic use in inhibiting several diseases [...]

In this paper, we study the bifurcations of non-linear dynamical systems. We continue to develop the analytical approach, permitting the prediction of the bifurcation of dynamics. Our approach is based on implicit (approximate) amplitude-frequency response equations of the form FΩ,A;c̲ =0, where c̲ denotes the parameters. We demonstrate that tools of differential geometry make possible the discovery of the change of differential properties of solutions of the equation FΩ,A;c̲ =0. Such qualitative changes of the solutions of the amplitude-frequency response equation, referred to as metamorphoses, lead to qualitative changes of dynamics (bifurcations). We show that the analytical prediction of metamorphoses is of great help in numerical simulation.

As a new type of composite bridge, the dynamic structural characteristics of a tensioned string bridge need to be deeply studied. In this paper, based on the structural characteristics of a tensioned string bridge, the Rayleigh method is used to derive formulas for calculating the frequencies of vertical, antisymmetric and lateral bending vibrations. The characteristics of the vertical and lateral bending vibration frequencies are summarized. The fundamental frequencies of the antisymmetric vertical bending and lateral bending of the tensioned string bridge are the same as that of the single-span beam under the corresponding constraint conditions. The shape and physical characteristics of the main cable have no effect on the frequency. The vertical bending symmetrical vibration frequency of the tensioned string bridge is greater than the corresponding symmetrical vibration frequency of the simply supported beam. The shape and physical characteristics of the main cable have a greater im... [more]

Ciprofloxacin (CIP), as a common antibiotic used in human clinical and livestock farming, is discharged into natural water bodies and its concentration has increased in the last years. Its stable chemical structure is difficult to remove by conventional techniques. Residual ciprofloxacin in the environment has become an emerging micropollutant that promotes the generation of resistance genes of bacteria and endangers ecosystem balance and human health. Removal of ciprofloxacin from water by the system of ultrasound/electric field/sodium persulfate (US/E/PS) was investigated. Firstly, CIP degradation affects by different oxidation methods, such as ultrasonic oxidation, electro-oxidation, and persulfate oxidation, and their four combined oxidation methods (ultrasound-activated persulfate oxidation, electro-activated persulfate oxidation, ultrasound-enhanced electro-oxidation, and ultrasound-enhanced electro-activated persulfate oxidation), on the target contaminants were compared. Second... [more]

The optimal process conditions when examining the antioxidant potential, total polyphenol content, and attribute liking in roasted rice germ flavored herbal tea were investigated using response surface methodology (RSM). The influence upon the extraction process of time and temperature was assessed using a full factorial design on three levels with two variables (32), involving five central point replicates. Extraction temperature (70 °C, 80 °C, and 90 °C) and extraction time (3 min, 4.5 min, and 6 min) served as independent variables, while the dependent variables were allocated to the regression equation to determine antioxidant activity (R2 = 0.941) along with total polyphenol content (R2 = 0.849), flavor liking score (R2 = 0.758), and overall liking score (R2 = 0.816). Following experimentation, it was determined that the optimal time and temperature conditions to maximize total polyphenol content, antioxidant activity, flavor, and overall liking score were in a range of 86 °C to 9... [more]

Recent discoveries have shown that calcium carbonate and soy protein interactions can be used to reinforce rubber composites with improvements on the effective crosslink density and moduli. However, the method to incorporate the soy protein into the rubber matrix may be costly to scale up, since it involves microfluidization and drying steps prior to rubber compounding. In this work, a simpler process involving dry-milled calcium carbonate and soy protein was used to explore filler blends of calcium carbonate, soy protein, biochar, and carbon black. By blending these filler materials in various ratios, rubber composite samples with 40−50% of the carbon black replaced by sustainable alternatives were made. These composites had essentially the same tensile strength, with better toughness and elongation properties relative to the carbon black control. These composites would reduce dependence on petroleum and be more amenable to the rubber composite compounding infrastructure.

Feature extraction plays a key role in fault detection methods. Most existing methods focus on comprehensive and accurate feature extraction of normal operation data to achieve better detection performance. However, discriminative features based on historical fault data are usually ignored. Aiming at this point, a global-local marginal discriminant preserving projection (GLMDPP) method is proposed for feature extraction. Considering its comprehensive consideration of global and local features, global-local preserving projection (GLPP) is used to extract the inherent feature of the data. Then, multiple marginal fisher analysis (MMFA) is introduced to extract the discriminative feature, which can better separate normal data from fault data. On the basis of fisher framework, GLPP and MMFA are integrated to extract inherent and discriminative features of the data simultaneously. Furthermore, fault detection methods based on GLMDPP are constructed and applied to the Tennessee Eastman (TE) p... [more]

With the changing world energy structure, the development of renewable energy sources is gradually accelerating. Among them, close attention has been given to geothermal energy because of its abundant resources and supply stability. In this article, a deep borehole heat exchanger (DBHE) is coupled with a heat pump system to calculate the heat supply and daily electricity consumption of the system. To make better use of the peaks and valleys in electricity prices, the following three daily operating modes were studied: 24-h operation (Mode 1), 8-h operation plus 16-h non-operation (Mode 2), and two cycles of 4-h operation and 8-h non-operation (Mode 3). Simulation results show that scheduled non-continuous operation can effectively improve the outlet temperature of the heat extraction fluid circulating in the DBHE. The heat extraction rates of Mode 1 is 190.9 kW for mass flowrate of 9 kg/s; in Mode 2 and Mode 3 cases, the rates change to 304.7 kW and 293.0 kW, respectively. The daily op... [more]

Modeling the thin-layer drying of foods is based on describing the moisture ratio versus time data by using a suitable mathematical model or models. Several models were proposed for this purpose and almost all studies were related to the application of these models to the data, a comparison and selecting the best-fitted model. A careful inspection of the existing drying data in literature revealed that there are only a limited number of curves and, therefore, the use of some models, especially the complex ones and the ones that require a transformation of the data, should be avoided. These were listed based on evidence with the use of both synthetic and published drying data. Moreover, the use of some models were encouraged, again based on evidence. Eventually, some suggestions were given to the researchers who plan to use mathematical models for their drying studies. These will help to reduce the time of the analyses and will also avoid the arbitrary usage of the models.

Molecular dynamics (MD) simulation is a particularly useful technique in food processing. Normally, food processing techniques can be optimized to favor the creation of higher-quality, safer, more functional, and more nutritionally valuable food products. Modeling food processes through the application of MD simulations, namely, the Groningen Machine for Chemical Simulations (GROMACS) software package, is helpful in achieving a better understanding of the structural changes occurring at the molecular level to the biomolecules present in food products during processing. MD simulations can be applied to define the optimal processing conditions required for a given food product to achieve a desired function or state. This review presents the development history of MD simulations, provides an in-depth explanation of the concept and mechanisms employed through the running of a GROMACS simulation, and outlines certain recent applications of GROMACS MD simulations in the food industry for the... [more]

This paper proposes the design and implementation of inductor-inductor-capacitor (LLC) converters with modules connected in series with the power scan method and communication scan network (CSN) to achieve MPPT and regulate the output voltage for the PV micro-grid system. The Dc/Dc converters includes six isolated LLC modules in series to supply ±380 V output voltage and track the maximum power point of the PV system. The series LLC converters are adopted to achieve high efficiency and high flexibility for the PV micro-grid system. The proposed global maximum power scan technique is implemented to achieve global maximum power tracking by adjusting the switching frequency of the LLC converter. To improve the system flexibility and achieve system redundancy, module failure can be detected in real time with a communication scan network, and then the output voltage of other modules will be changed by adjusting the switching frequency to maintain the same voltage as before the failure. Addi... [more]

In recent years, many large-scale plantings have become refined small-scale or home plantings. The rapid progress of agriculture technologies and information techniques enables people to control the growth of agricultural products well. Hence, this study proposes an Artificial Intelligence of Things (AIoT) based Plant Pot Design for planting edible mint in an office setting, which is called APPD. APPD is composed of intelligent gardens and a cloud-based service platform. An intelligent garden is deployed an Arduino with multiple sensors to monitor and control plant pots of the edible mint, Mentha spicata. The cloud-based service platform provides a Case-Based Reasoning (CBR) inference engine with a database for adjustment influence factors. This study discusses eight growing statuses of Mentha spicata with different illumination, photometric exposure, and moisture content, designed for an office environment. Evaluation results indicate that Mentha spicata with 16 h red−blue lighting an... [more]

Biodiesel, which is composed of mono-alkyl esters of long carbon-chained fatty acids, is used as an alternative fuel to petro-diesel. The water content of the reactant mixture of feedstock oil influences the extent of transesterification and thus the fuel characteristics. Lower water content in feedstock oil is generally suggested for successful transesterification. This experimental study removed water from the reactant mixture of feedstock palm oil and methanol during transesterification using various systems composed of either electrodes or molecular sieves with rotary vibration. The effect of input electrical energy, number of electrodes, vibration modes, and operating time on the amount of water removed from the reactant mixture and the fuel properties of the final biodiesel product were analyzed and compared with those achieved using molecular sieves. The results show that the biodiesel—after water was removed during transesterification—appeared to have increased kinematic viscos... [more]

The main objective of the present work was to study the drying kinetics and obtain the optimum process parameters of cantaloupe slices using short-and medium-wave infrared radiation (SMIR) drying technology. The effect of three independent variables of infrared radiation temperature (55−65 °C), slice thickness (5−9 mm) and radiation distance (80−160 mm) on the L value, color difference (∆E), hardness and vitamin C content were investigated by using the Response Surface Methodology (RSM). The results showed that the Page model can adequately predict the moisture content between 55 and 65 °C (R2 > 0.99). The effective moisture diffusivity (Deff) varied from 5.26 × 10−10 to 2.09 × 10−9 m2/s and the activation energy (Ea) of the SMIR drying was 31.84 kJ/mol. Infrared radiation temperature and slice thickness exerted extremely significant effects on L value and color difference (ΔE) (p < 0.01), with higher infrared radiation temperature and thin slice thickness leading to a decrease in t... [more]

Novel profile control agents are constantly emerging in the field of enhanced oil recovery, contributing to the extension of a stable production period. However, evaluation performed through conventional core flow experiments is usually inadequate to reveal the in-depth mechanism of profile control agents. Besides, due to different operation and production modes, there is an urgent need for a specific experimental method applicable to horizontal wells in bottom water reservoirs. In this context, this paper describes two models tailored to bottom water reservoirs and investigates the flow characteristics and mechanisms of three water-shutoff agent types. At the pore scale, further study was carried out on the water-shutoff synergism between a gel and an emulsifier. The results show that the gel is present at the edge of the pore body, while the emulsion is blocked in the center of the pore body. Hence, gel that enters a water channel (main flow and accumulation area of emulsion) can coo... [more]

In this work, the feasibility of chemoenzymatically transforming biomass-derived D-xylose to furfuryl alcohol was demonstrated in a tandem reaction with SO42−/SnO2-CS chemocatalyst and reductase biocatalyst in the deep eutectic solvent (DES)−water media. The high furfural yield (44.6%) was obtained by catalyzing biomass-derived D-xylose (75.0 g/L) in 20 min at 185 °C with SO42−/SnO2-CS (1.2 wt%) in DES ChCl:EG−water (5:95, v/v). Subsequently, recombinant E.coli CF cells harboring reductases transformed D-xylose-derived furfural (200.0 mM) to furfuryl alcohol in the yield of 35.7% (based on D-xylose) at 35 °C and pH 7.5 using HCOONa as cosubstrate in ChCl:EG−water. This chemoenzymatic cascade catalysis strategy could be employed for the sustainable production of value-added furan-based chemical from renewable bioresource.

In the context of sustainable use of resources, hydrothermal conversion of biomass has received increased consideration. As well, the hydrochar (the solid C-rich phase that occurs after the process) has caused great interest. In this work, spruce bark (Picea abies) wastes were considered as feedstock and the influence of hydrothermal process parameters (temperature, reaction time, and biomass to water ratio) on the conversion degree has been studied. Using the response surface methodology and MiniTab software, the process parameters were set up and showed that temperature was the significant factor influencing the conversion, while residence time and the solid-to-liquid ratio had a low influence. Furthermore, the chemical (proximate and ultimate analysis), structural (Fourier-transform infrared spectroscopy, scanning electron microscopy) and thermal properties (thermogravimetric analysis) of feedstock and hydrochar were analyzed. Hydrochar obtained at 280 °C, 1 h processing time, and 1... [more]

In the process of underground mining, steeply inclined rocks or coal seams are often encountered, forming the openings of right-angle trapezoid. According to the geological conditions of a mining project in China, an analytical elastic solution of stress and displacement around right-angle trapezoidal opening in a homogeneous, isotropic, and linear elastic geomaterial is presented, which is based on the evaluation of the conformal mapping representation by an appropriate numerical calculation and the complex potential functions. The different results from other shaped openings are shown as follows. In a right-angle trapezoidal opening, the maximum displacements of roof falling occur on the low side, while the most horizontal displacements on the low side are around the roof and the most horizontal displacements on the high side are around the middle of the high side in this opening. These results are also compared with the numerical calculations in FLAC software, illustrating that the... [more]

A partial-denitrification coupling with anaerobic ammonium oxidation (anammox) process (PD/A) in a continuous-flow anoxic/oxic (A/O) biofilm reactor was developed to treat carbon-limited domestic wastewater (ammonia (NH4+-N) of 55 mg/L and chemical oxygen demand (COD) of 148 mg/L in average) for about 200 days operation. Satisfactory NH4+-N oxidation efficiency above 95% was achieved with rapid biofilm formation in the aerobic zone. Notably, nitrite (NO2−-N) accumulation was observed in the anoxic zone, mainly due to the insufficient electron donor for complete nitrate (NO3−-N) reduction. The nitrate-to-nitrite transformation ratio (NTR) achieved was as high as 64.4%. After the inoculation of anammox-enriched sludge to anoxic zones, total nitrogen (TN) removal was significantly improved from 37.3% to 78.0%. Anammox bacteria were effectively retained in anoxic biofilm utilizing NO2−-N produced via the PD approach and NH4+-N in domestic wastewater, with the relative abundance of 5.83% fo... [more]

This research numerically studies the transient cooling of partially liquid magma by natural convection in an enclosed magma chamber. The mathematical model is based on the conservation laws for momentum, energy and mass for a non-Newtonian and incompressible fluid that may be modeled by the power law and the Oberbeck−Boussinesq equations (for basaltic magma) and solved with the finite volume method (FVM). The results of the programmed algorithm are compared with those in the literature for a non-Newtonian fluid with high apparent viscosity (10−200 Pa s) and Prandtl (Pr = 4 × 104) and Rayleigh (Ra = 1 × 106) numbers yielding a low relative error of 0.11. The times for cooling the center of the chamber from 1498 to 1448 K are 40 ky (kilo years), 37 and 28 ky for rectangular, hybrid and quasi-elliptical shapes, respectively. Results show that for the cases studied, natural convection moved the magma but had no influence on the isotherms; therefore the main mechanism of cooling is conduct... [more]

The link between hydrodynamics and biological process behavior of antibody-producing mammalian cell cultures is still not fully understood. Common methods to describe dependencies refer mostly to averaged hydrodynamic parameters obtained for individual cultivation systems. In this study, cellular effects and locally resolved hydrodynamics were investigated for impellers with different spatial hydrodynamics. Therefore, the hydrodynamics, mainly flow velocity, shear rate and power input, in a single- and a three-impeller bioreactor setup were analyzed by means of CFD simulations, and cultivation experiments with antibody-producing Chinese hamster ovary (CHO) cells were performed at various agitation rates in both reactor setups. Within the three-impeller bioreactor setup, cells could be cultivated successfully at much higher agitation rates as in the single-impeller bioreactor, probably due to a more uniform flow pattern. It could be shown that this different behavior cannot be linked to... [more]

An automated mechanical transmission (AMT) is proposed as a new soft starter for medium-scale belt conveyors in this paper. The AMT is used to start the belt conveyor and shift gears step by step to make the belt conveyor accelerate softly. Based on analyzing common soft-starting acceleration curves, a segmented belt acceleration curve is proposed as a new soft-starting acceleration curve. By analyzing the AMT soft-starting system, the system modeling is built and the AMT output shaft’s angular acceleration is proposed to be controlled to control the belt acceleration. The AMT soft-starting simulation model is established in the environment of AMESim, and simulation results of the soft-starting process from the first to eighth gear positions are given. The main parameter curves of the AMT soft-starting system including the belt, driving pulley, and AMT output shaft are analyzed. The simulation model can indicate the viscoelastic property of the belt. The simulation results prove that t... [more]

Wind energy has become one of the world’s most renewable energy sources in recent years. It is regarded as a clean energy source because it produces no greenhouse gas emissions. The assessment of wind energy resources is an important step in the development of any wind energy conversion system (WECS). As a result, this article examines the wind energy potential of nine Jordanian wind locations: Queen Alia Airport, Civil Amman Airport, King Hussein Airport, Irbid, Mafraq, Ma’an, Ghor Al Safi, Safawi, and Irwaished. The available wind speed data were implemented using three statistical distribution models, Weibull, Rayleigh, and Gamma distributions, and one traditional estimation method, the Maximum Likelihood Method (MLM). Three optimization techniques were used to assign parameters to each distribution model: Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Whale Optimization Algorithm (WOA). To determine the optimal distribution model, the performance of these distrib... [more]

We studied the epoxy polymer surface modification using air plasma treatment in a Gliding Arc (GA) plasma reactor and a pulsed Dielectric Barrier Discharge (DBD). We employed optical emission spectroscopy (OES) measurements to approximate the vibrational and rotational temperatures for both plasma sources, as well as surface temperature measurements with fiber optics and IR thermography to corelate with the corresponding hydrophilization of the epoxy material. Water contact angle measurements revealed a rapid hydrophilization for both plasma sources, with a slightly more pronounced effect for the air DBD treatment. Ageing studies revealed stable hydrophilicity, with water contact angle saturating at values lower than 50°, corresponding to a >50% decrease compared to the untreated epoxy polymer. ATR-FTIR spectroscopy studies showed an additional absorption band assigned to carbonyl group, with its peak intensity being higher for the DBD treated surfaces. The spectra were also correlated... [more]