The environmental pollution due to wastewater, especially domestic wastewater, is becoming more serious. Thus, this study was performed to assess the removal of pollutants by the combination of wetland technology, specifically constructed wetland (CW), with Para grass (Brachiaria mutica) together with the adsorption of red sludge. With an organic loading rate (OLR) of 120 (kg COD/ha/day), the treatment efficiency for wastewater in this study is quite high and the concentrations of parameters in the effluent were lower than the limits established by the QCVN 14:2015/BTNMT for domestic wastewater, which indicated the feasibility of this combination. These results are expected to open the possibilities of using environmentally friendly processes for wastewater treatment in urban and industrial areas.

The optimization of red pigment anthocyanin from roselle (Hibiscus sabdariffa) by subcritical water extraction (SWE) has not been the topic of a scientific investigation. Therefore, the objective of this paper was to establish the optimal parameters for obtaining the maximum yield, total anthocyanin compounds (TAC), total phenolic compounds (TPC), and total flavonoid compounds (TFC) by SWE utilizing a response surface methodology. The optimal conditions were 8.75 MPa, 393.54 K, and 4.89 mL/min, with a yield of 0.69 g/g, TAC of 927.74 mg/100 g, TPC of 39.54 mg/100 g, and TFC of 614.57 mg/100 g. High temperatures and flow rates are favorable for achieving a maximum yield. In contrast, a high temperature is suitable for obtaining high concentrations of anthocyanin, flavonoid, and phenolic compounds. This technique (SWE) recovers anthocyanin at a greater extraction rate than traditional methods; hence, SWE may be substituted for conventional methods for extracting anthocyanin.

Coal is the mainstay of China’s energy supply. With the gradual progress in China’s policy of phasing out backward coal production capacity, the intensive and deep mining of coal has gradually become the new norm. The current mining depth is increasing at a rate of 10~15 m/year. The high crust stress, high gas pressure, high ground temperature, and engineering disturbance stress in deep coal mines can lead to the occurrence of coal−rock−gas dynamic disasters that are complex and show the characteristics of compound dynamic disasters. It is important to understand the evolution and mechanism of deep coal and rock dynamic disasters accurately for the safe development of deep resources. To study the mechanism of occurrence and the evolution of impact−protrusion compound dynamic disasters, we herein analyzed the apparent characteristics of coal−rock−gas compound dynamic disasters in deep mines and obtained the mechanical and acoustic emission characteristics of coal−rock composites through... [more]

Owing to exceptionally high selectivity, membranes based on palladium alloys are widely used for obtaining high-purity hydrogen. An important issue for providing high hydrogen permeability of the membranes is to form the required phase composition. The structural organization of the solid solutions consisting of Cu−36.4 at .% Pd and Cu−50 at .% Pd were studied by X-ray diffraction (XRD), electron diffraction (ED), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDXS). It was found that the former composition can be ordered in the temperature range of 300−400 °C and in the heating (up to 800 °C)−cooling cycle. In the presence of excess Cu atoms (27.2%), this structure can be represented by CsCl type structural units (β-phase) and distributed body center cubic (BCC) copper structural units in the corresponding concentration dose. The formation of a single crystal ordered phase within the mosaic blocks of the disordered phase was establis... [more]

Additives are widely used to enhance the rheological and performance properties of asphalt binder to satisfy the demands of extreme loading and climatic conditions. Meanwhile, adding to the complexity of asphalt binder behaviour that requires more time, effort, and material resources during laboratory work. The purpose of this research was to use Artificial Neural Networks (ANNs) to predict the recovery (R) and nonrecoverable compliance (Jnr) behaviour of asphalt binder based on mechanical test parameters and rheological properties of asphalt binder. A comprehensive experimental database consisting of the results of the frequency sweep and Multiple Stress Creep Recovery (MSCR) test using a dynamic shear rheometer (DSR) at five test temperatures (46 ∘C, 52 ∘C, 58 ∘C, 64 ∘C, and 70 ∘C). Prediction models for R and Jnr of asphalt binder modified with different contents of fly ash, fly ash-based geopolymer, glass powder/fly ash-based geopolymer, and styrene−butadiene styrene (SBS) were dev... [more]

Cybersecurity protocols enable several levels of protection against cyberattacks (digital attacks) that spread across network devices, platform programs, and network applications. On the Internet of Things (IoT), cyberattacks are generally intended to access and change/destroy sensitive information, which may reduce IoT benefits. Moreover, recent IoT systems are experiencing a critical challenge in designing a lightweight and robust cybersecurity mechanism on resource-constrained IoT devices. The cybersecurity challenges facing the IoT that should be taken into consideration are identifying compromised devices, data/service protection, and identifying impacted IoT users. This paper proposes an unforgeable digital signature integrated into an effective lightweight encryption (ELCD) mechanism that utilizes the secure key distribution in an elliptic curve Diffie−Hellman (ECDH) and resolves the weak bit problem in the shared secret key due to the Diffie−Hellman exchange. The ELCD mechanism... [more]

Improving the accuracy of pressure prediction in the wellbore annular is of great importance for the design in oil and gas production. However, due to the existence of double-layer liquid membrane and the lack of relevant experiments, the existing correlations fail to the field application. In this study, a new model of flow pattern transition in inclined annulus pipe is proposed by using a mechanistic approach to classify the flow patterns. Firstly, a gas-liquid two-phase flow experiment in annulus pipe was carried out in a pipe with an outer diameter of 73.02 mm and an inner diameter of 121.36 mm, and then the influence of inclined angle on the transition boundary of flow pattern is discussed. Finally, a hydrodynamic transition criterion for the flow pattern model of inclined annulus pipe is established and verified in detail. The experimental results show that bubble flow, slug flow, churn flow and annular flow were observed under different inclination angles, and the results indica... [more]

Improving coal resource mining rates has long been a focus of coal industry research. The gob-side entry retaining by roof cutting (GERRC) is a new coal mining technology that has gained popularity in China due to its high mining rate and safety. Based on the GERRC technology, the precise technical procedure is elaborated, and the fundamental idea of pressure relief is explored through creating a structural mechanics model of the surrounding rock in this paper. The results of mechanical analysis show that the primary mechanism of roof pressure release is to weaken the integrity of the roof, thereby reducing the ultimate bending moment of the rock stratum. In addition, an additional strategy for pressure release is suggested in this research, involving the weakening of the roof rock by the creation of dense pressure-released holes. The results of the engineering field experimentation demonstrate that the dense pressure-released holes can completely replace the conventional blasting tech... [more]

As giant magnetostrictive material, TbDyFe is regarded as a promising choice for magnetic sensing due to its excellent sensitivity to changes in magnetic fields. To satisfy the requirements of high sensitivity and the stability of magnetic sensors, TbDyFe thin films were successfully deposited on single-crystal diamond (SCD) substrate with a Young’s modulus over 1000 GPa and an ultra-stable performance by radio-frequency magnetron sputtering at room temperature. The sputtering power and deposition time effects of TbDyFe thin films on phase composition, microstructure, and magnetic properties were investigated. Amorphous TbDyFe thin films were achieved under various conditions of sputtering power and deposition time. TbDyFe films appeared as an obvious boundary to SCD substrate as sputtering power exceeded 100 W and deposition time exceeded 2 h, and the thickness of the films was basically linear with the sputtering power and deposition time based on a scanning electron microscope (SEM)... [more]

The vegetation covering regions is confined due to deforestation, mining industries, and environmental factors. The intensified deforestation and industrial development processes impact the vegetation coverage and fail to meet the food demands. Therefore, accurate monitoring of such regions aids in preventing adversary processes and their plant extinction. The monitoring process requires accurate data collection and analysis to identify the root cause that can be due to human/climatic/environmental changes. This article introduces a concentrated stream data processing method (CSDPM) assisted by an extreme learning paradigm. The different causes are analyzed using the extracted features in different learning perceptron layers. In this learning, the accumulated data is analyzed for similar features and trained for the consecutive or lagging input data streams. The monitoring process concluded with the learning output by classifying the plant extinction reason. Therefore, the identified r... [more]

Networked nonlinear systems (NNSs) have great potential security threats because of malicious attacks. These attacks will destabilize the networked systems and disrupt the communication to the networked systems, which will affect the stability and performance of the networked control systems. Therefore, this paper aims to deal with the resilient control problem for NNSs with dynamically triggering mechanisms (DTMs) and malicious aperiodic denial-of-service (DoS) attacks. To mitigate the impact from DoS attacks and economize communication resources, a resilient dynamically triggering controller (RDTC) is designed with DTMs evolving an adaptive adjustment auxiliary variable. Thus, the resulting closed-loop system is exponentially stable by employing the piecewise Lyapunov function technique. In addition, according to the minimum inter-event time, the Zeno behavior can be excluded. Finally, the merits of the proposed controllers and theory are corroborated using the well-known nonlinear C... [more]

This study investigates the physical parameters that affect the flow patterns of soybeans with various moisture content (12% to 60%) at varying orifice sizes (20, 40, and 60 mm) in a cylindrical silo. The flow conditions required to obtain a steady mass flow during discharge were evaluated via experiments and three-dimensional discrete element method (DEM) simulation. The discharged mass flow rates at different flow conditions provided the critical size of the orifice. If the reduced diameter (Dred) of an orifice is >5.59, the flow showed a steady state. Based on the mass flow index (MFI), the flow patterns at 40% and 60% moisture content at 40 and 60 mm orifice sizes, respectively, showed funnel flows. although these flow conditions were satisfied to maintain a steady flow. The maximum wall pressure for the funnel flow showed the location of the interlocking phenomenon where the stagnant zone began during discharging. DEM simulation was validated through the mass profiles using the pa... [more]

Considering the increasing frequency of geological disasters related to groundwater activities, it is important to study the relationship between geological dislocation and groundwater flow for the safety assessment of engineering rock mass stability. To elucidate the non-linear seepage characteristics at rock discontinuities during shearing, a custom-made device was used to conduct seepage tests at discontinuities that exhibit varying undulation angles and different shear displacements. The results show that as the shear displacement increases, the shear stress at a structural plane involving different undulation angles fluctuates with an increasing trend. Based on an identical shear displacement condition, the shear strengths of the structural planes increase as the undulation angle increases, and this enhances the shear expansion. Concerning an identical fluctuation angle and hydraulic gradient, the seepage flow at a structural plane increases as the shear displacement increases. By... [more]

Fumaric acid is one of the most promising biorefinery platform chemicals, fruit residues being a very suitable raw material for its production in second generation biorefineries. In particular, apple pomace is a plentiful residue from the apple juice industry, with apple being the second largest fruit crop in the world, with a production that increased from 46 to 86 Mtons in the 1994−2021 period. With a global apple juice production of more than 4.5 Mtons, a similar amount of apple pomace is produced yearly. In this work, apple pomace hydrolysate has been obtained by enzymatic hydrolysis and further characterized for its content in sugars, phenolics and nitrogen using different analytic methods, based on HPLC and colorimetric techniques. Previous to the use of this hydrolysate (APH), we studied if the addition of fructose to the usual glucose-rich broth could lead to high fumaric acid yields, titers and productivities. Afterwards, APH fermentation was performed and improved using diffe... [more]

The distribution and evolution of air in airliner cabins is an important basis for the study of cabin thermal environment and pollutant propagation. Due to the complex heat and mass transfer problems caused by forced and natural convection in a large-scale space, the accurate prediction of air distribution in airliner cabins still faces huge challenges. This study takes the cabin of the Airbus A320 as the research object. The accurate numerical simulation of the flow and heat transfer process in an airliner cabin under mixing ventilation mode was carried out using the Hybrid Thermal Lattice Boltzmann Method (HTLBM) combined with GPU (Graphics Processing Unit) acceleration technology, and the influence of human thermal plumes on air distribution and evolution characteristics in an airliner cabin was analyzed. The research shows that the human thermal plume changes the air distribution in the passenger cabin. The thermal plume slows down the jet attenuation, increases the energy exchange... [more]

In this work, slim tube displacement tests for minimum miscibility pressure MMP were carried out. Based on the displacement data, the MMP was calculated by statistical regression using linear and quadratic extrapolation with threshold values of 90% and 95% oil recovery as well as the intersection of trend lines for immiscible and miscible displacement regimes. The obtained data show a significant variation in the range of MMP values depending on the calculation method. To clarify the MMP value, an analysis of displacement dynamics was carried out. The ratio of the volume flow rate of reservoir oil to the volume flow rate of the injected gas—flow rates ratio (FFR)—was used as a new parameter. The MMP value calculated from the FRR value extrapolation was determined as 37.09 MPa. According to the results obtained, the proposed methodology based on the displacement dynamics can be useful as a criterion for clarifying the MMP value in slim tube displacement experiments.

With the need for ultra-low emissions and the strict regulation of PCDD/Fs from MSWI plants, traditional SCR catalysts have been applied to remove PCDD/Fs. In this study, we compared one typical commercial V2O5-MoO3/TiO2 catalyst’s performance in removing PCDD/Fs under laboratory and industrial conditions. Various characterization methods like XRF, XPS, BET, and H2-TPR were applied to analyze the catalyst’s properties. The laboratory results showed that the adsorption could significantly affect the removal at low temperatures. The RE on PCDD/Fs was 59.4% (55.0% for toxicity RE), 88.5% (90.3%), and 78.0% (76.0%) at 160 °C, 180 °C, and 200 °C, respectively, showing that 180 °C is the most suitable operation temperature for this V2O5-MoO3/TiO2 catalyst. The field study was conducted at 180 °C, and the results revealed that the competition between water vapor and the interaction of SO2 could lower the RE. However, comparisons between laboratory and field conditions showed that this V2O5-Mo... [more]

To solve the anti-disturbance control problem of dissolved oxygen concentration in the wastewater treatment plant (WWTP), an anti-disturbance control scheme based on reinforcement learning (RL) is proposed. An extended state observer (ESO) based on the Takagi−Sugeno (T-S) fuzzy model is first designed to estimate the the system state and total disturbance. The anti-disturbance controller compensates for the total disturbance based on the output of the observer in real time, online searches the optimal control policy using a neural-network-based adaptive dynamic programming (ADP) controller. For reducing the computational complexity and avoiding local optimal solutions, the echo state network (ESN) is used to approximate the optimal control policy and optimal value function in the ADP controller. Further analysis demonstrates the observer estimation errors for system state and total disturbance are bounded, and the weights of ESNs in the ADP controller are convergent. Finally, the effec... [more]

Evolutionary Population Dynamics (EPD) refers to eliminating poor individuals in nature, which is the opposite of survival of the fittest. Although this method can improve the median of the whole population of the meta-heuristic algorithms, it suffers from poor exploration capability to handle high-dimensional problems. This paper proposes a novel EPD operator to improve the search process. In other words, as the primary EPD mainly improves the fitness of the worst individuals in the population, and hence we name it the Fitness-Based EPD (FB-EPD), our proposed EPD mainly improves the diversity of the best individuals, and hence we name it the Diversity-Based EPD (DB-EPD). The proposed method is applied to the Grey Wolf Optimizer (GWO) and named DB-GWO-EPD. In this algorithm, the three most diversified individuals are first identified at each iteration, and then half of the best-fitted individuals are forced to be eliminated and repositioned around these diversified agents with equal pr... [more]

Real-time monitoring of antibiotics in hospital and pharmaceutical wastewater using ultraviolet−visible (UV−Vis) spectroscopy is considered a promising method. Although gas chromatography−mass spectrometry (GC−MS) and other methods can detect antibiotics with quite low limits of detection (LOD), they possess various limitations. UV−Vis spectroscopy combined with chemometric methods is a promising choice for monitoring antibiotics. In this study, two immersed in situ UV−Vis sensors were used to explore the relationship between absorption spectra and antibiotics and study the influence of the optical path length on the LOD. The LODs of sensor 2 using a 10 cm optical path is up to 300 times lower than that of sensor 1 using a 0.5 mm optical path. Moreover, multiple antibiotics in the wastewater were investigated in real-time manner. The absorption spectra of 70 groups of wastewater samples containing different concentrations of tetracycline, ofloxacin, and chloramphenicol were measured. T... [more]

Dry dust collectors are a typical dust and gas coexistence space. Dust explosion risk assessments should be performed for effective prevention and control of dust explosion accidents. In this paper, a dust explosion risk assessment index system for dust removal systems was constructed following the dust characteristics and the actual operation of a dry dust collector. The proposed system consisted of three first-level indexes (dust explosion characteristic parameters, environmental parameters in the dust collector box, use state of explosion prevention and control device) and seven second-level indexes (dust explosion sensitivity, dust explosion severity, temperature in the dust collector box, pressure difference between inlet and outlet, operating state of spark detection, operating the explosion venting disc, and operating state of the lock gas ash discharge valve). The analytic hierarchy process was adapted to calculate the weight of each index. Additionally, a dust explosion risk a... [more]

Trochoid milling can improve the quality of machining of difficult materials as well as the efficiency of machining. However, its complex tool trajectory makes it difficult to predict the instantaneous cutting forces during cutting. Therefore, in this paper, the transient cutting thickness model in the cycloidal milling process was established using numerical combined with analytical methods, and the semi-mechanical cutting force model was established. Experiments were designed to compare the differences between the cutting force coefficients extracted from the slot milling experiments and those extracted from the trochoid milling. Finally, experiments were designed to validate the established cutting force model. The results showed that there was an error of 5−23% between the tangential cutting force coefficients extracted from slot milling and the tangential cutting force coefficients extracted from trochoid milling, while there was an error of 21−35% in the radial cutting force coef... [more]

This paper studies the voltage stability of the Slovak Republic’s power system (PS) based on an assessment of the PV curves. The PV curve is a tool for assessing voltage stability, and based on its shape, it is possible to determine weak and strong voltage nodes with the possibility of voltage stability reserve quantification. We present an analysis of the influence of transformers with an automatic voltage regulator (AVR) on the shape of the PV curves and on the magnitude of voltage in the PS. In general, the 400 kV/110 kV transformers equipped with AVRs are critical assets for the PS as they address voltage control in the DS. However, in the case of voltage problems in the TS, the AVR function may worsen the voltage situation across the entire PS. Therefore, we closely analyze the negative effects of the AVR on the PS operation. This impact is clearly proved, and recommendations are given for the transmission system operator (TSO) in order to maintain voltage stability. In addition,... [more]

During the development of shale gas, one of the major challenges is the casing deformation (CD) in the horizontal section due to the geological activity. Recently, the casing deformation before hydraulic fracturing (CDBF) occurred in multiple shale gas wells in L block in China. In this paper, based on the theory of tubular mechanics, the relationship between casing buckling and CDBF caused by casing running in is analyzed qualitatively and quantitatively. It is found that the buckling deformation caused by running the casing string process is not sufficient to prevent the tool (Φ99 mm bridge plug). On the other hand, the mechanism of CDBF is systematically analyzed based on the actual field data and finite element (FE) method. In order to analyze the CDBF mechanism, the comparison between the actual casing trajectory and the reservoir rock (S#1, S#2, S#3 and M#1) in horizontal section in H2 platform is carried out, and the preliminary CDBF mechanism is proposed. Then, two groups of FE... [more]

The aim of this work is to evaluate thermal behaviors and develop a soft sensor for online prediction of LOD (loss-on-drying) in the segmented fluidized bed dryer (Seg-FBD) in the ConsiGma25 line, which is regarded as the intermediate critical quality attribute for the final drug product. Preheating and drying experiments are performed and heat transfers and conductions among the Seg-FBD are evaluated based on the temperature measurements from sensors and an infrared thermal camera. A temperature distribution in dryer cells and high heat conductions in walls are found. Considerable heat transfers between the neighboring dryer cells are determined, which equal approximately 7% of the energy provided from the heated air. The cell-to-cell heat transfers are implemented into the heat transfer and drying models of the Seg-FBD. The models are calibrated successively in gPROMS Formulated Products (gFP) and the temperature and LOD errors are less than 2 °C and 0.5 wt.%, respectively. Subsequen... [more]