The Eclat algorithm is a typical frequent pattern mining algorithm using vertical data. This study proposes an improved Eclat algorithm called ETPAM, based on the tissue-like P system with active membranes. The active membranes are used to run evolution rules, i.e., object rewriting rules, in parallel. Moreover, ETPAM utilizes subsume indices and an early pruning strategy to reduce the number of frequent pattern candidates and subsumes. The time complexity of ETPAM is decreased from O(t2) to O(t) as compared with the original Eclat algorithm through the parallelism of the P system. The experimental results using two databases indicate that ETPAM performs very well in mining frequent patterns, and the experimental results using four databases prove that ETPAM is computationally very efficient as compared with three other existing frequent pattern mining algorithms.

Despite that diclofenac has been embodied to the European watch list of priority substances of concern, studies on diclofenac biodegradation are limited and the diversity of diclofenac-degrading microbiota remains unknown. In this work, an immobilized cell biofilter was constructed and operated to evaluate its effectiveness to depurate high strength diclofenac wastewater and to identify the diclofenac-degrading community accommodated in activated sludge by employing high-throughput sequencing techniques. After a two-month adaptation period, biofilter removal efficiencies reached values as high as 97.63 ± 0.62%, whereas utilization of diclofenac in the immobilized cell biofilter led to a drastic pH decrease. Based on Illumina sequencing, the major bacterial taxa identified in the immobilized cell biofilter were members of the species Granulicella pectinivorans and Rhodanobacter terrae, followed by members of the species Castellaniella denitrificans, Parvibaculum lavamentivorans, Bordete... [more]

This paper presents an experimental evaluation of a closed loop lake water heat pump (LWHPs) system based on the slinky coiled configuration. Initially, a mathematical model is developed in the Engineering Equation Solver (EES) for the heat pump system and the submerged coils in a lake. System performance is determined for the submerged slinky copper coils under the various operating conditions. Afterwards, parametric analysis is performed considering different influencing parameters, such as the lake water temperature, ambient temperature, and mass flow rate of the circulating fluid at constant lake depth of 4 ft. The experimental setup is developed for 3.51 kW cooling capacity after cooling load calculation for a small room. In the current study, slinky copper coils are used to exchange heat with lake water. The experimental setup is installed in Taxila, Pakistan, and the system’s performance is analyzed during selected days. After experimentation based on hourly and daily operation... [more]

In order to explore the distribution law of stress field under the mining mode of gob-side entry retaining by roof cutting without pillar (GERRCP) under goaf, based on the engineering background of 8102 and 9101 working faces in Xiashanmao coal mine, the stress field distribution of GERRCP and traditional remaining pillar was studied by means of theoretical analysis and numerical simulation. The simulation results showed that: (1) in the front of the working face, the vertical peak stress of non-pillar mining was smaller than that of the remaining pillar mining, and it could effectively control stress concentration in surrounding rock of the mining roadway; the trend of horizontal stress distribution of the two was the same, and the area, span and peak stress of stress the rise zone were the largest in large pillar mining and the minimum in non-pillar mining. (2) On the left side of the working face, the vertical stress presented increasing-decreasing characteristics under non-pillar m... [more]

The mixing and disinfection performance of a full-scale chlorine contact tank (CCT) is thoroughly investigated by means of numerical simulations for seasonal water supply variations in the water treatment plant (WTP) of Eskisehir in Turkey. Velocity measurements and tracer studies are carried out on a 1:10 scale laboratory model of the CCT to validate the numerical model. A good agreement between numerical and experimental results shows that the numerical model developed can be reliably used for the simulation of turbulent flow and solute transport in the full-scale CCT. Tracer studies indicate that the hydraulic performance of the CCT is classified as “average” according to the baffling factor, while the Morrill, Aral-Demirel (AD), and dispersion indexes indicate low mixing due to the recirculating and short-circuiting effects inside the chambers of the CCT. With respect to the first order modeling of chlorine decay and pathogen inactivation, chlorine concentrations are found to be si... [more]

Clustering techniques can group genes based on similarity in biological functions. However, the drawback of using clustering techniques is the inability to identify an optimal number of potential clusters beforehand. Several existing optimization techniques can address the issue. Besides, clustering validation can predict the possible number of potential clusters and hence increase the chances of identifying biologically informative genes. This paper reviews and provides examples of existing methods for clustering genes, optimization of the objective function, and clustering validation. Clustering techniques can be categorized into partitioning, hierarchical, grid-based, and density-based techniques. We also highlight the advantages and the disadvantages of each category. To optimize the objective function, here we introduce the swarm intelligence technique and compare the performances of other methods. Moreover, we discuss the differences of measurements between internal and external... [more]

The study attempts the optimization of the total flavonoid content (TFC) and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) antioxidant activity of the white radish (Raphanus sativus L.) root ethanolic extract (WRE) with regard to several parameters including ethanol concentration, the ratio of solvent/material, temperature and extraction time. Then antifungal analysis of WRE was performed against four fungal species including Aspergillus flavus NBRC 33021, Aspergillus niger NBRC 4066, Aspergillus clavatus NBRC 33020, and Fusarium solani NBRC 31094. At the WRE concentration of 75 mg/mL, diameters of inhibition zone were 9.11 ± 1.5, 19.55 ± 1.68, 17.72 ± 0.25, and 17.50 ± 0.73 mm respectively against the four examined species. Minimum fungal concentration (MFC) values of WRE against the four species were 30, 10, 20 and 30 mg/mL respectively. Evaluation of the sponge cake added with white radish root extract suggested that shelf-life of the sponge cake is 8 weeks in a... [more]

Organic waste exploitation is crucial for waste emissions restraint in air, soil and water. This type of waste can be exploited to produce biogas, a valuable fuel exploitable for energy purposes. A circular approach for energy production is much cleaner and more sustainable than the traditional linear approach. In this work, organic waste was used for biogas production to feed a highly efficient solid oxide fuel cell power generator, which requires an ultra-purified fuel. Commercial sorbents were experimentally studied in conjunction with a dynamic adsorption model to predict the breakthrough time and organize the material change-over. In the presence of 0.1% oxygen in the gas mixture, AirDep® CKC showed a marked increase in the adsorption capacity (from 3.91 to 84.87 mg/g), overcoming SulfaTrap® R8G (49.91 mg/g). The effect of several operating parameters on adsorption capacity was evaluated: inlet H2S concentration, filter geometry and gas mixture velocity. Experimental data revealed... [more]

The performance of a CO2 double-pipe evaporator was studied through experiments and a simulation model that was established by the steady-state distribution parameter method and experimentally verified while using a CO2 transcritical water‒water heat pump system. The effects of different operating parameters on heat transfer performance were studied over a range of evaporation temperatures (−5 to 5 °C), mass velocity (100‒600 kg/m2s), and heat flux (5000‒15,000 W/m2). It was found that the dryout quality increased at a small evaporation temperature, a large mass velocity, and a small heat flux. The simulation yield means relative error (RE) of heat transfer for the evaporation temperature and that of the CO2 pressure drop for the chilled water inlet temperature were 5.21% and 3.78%, respectively. The effect of tube diameter on the performance of CO2 double-pipe evaporator is probed through simulations. At the same time, this paper defines a parameter α , which is the proportio... [more]

In this work, a closed-loop identification method based on a reinforcement learning algorithm is proposed for multiple-input multiple-output (MIMO) systems. This method could be an attractive alternative solution to the problem that the current frequency-domain identification algorithms are usually dependent on the attenuation factor. With this method, after continuously interacting with the environment, the optimal attenuation factor can be identified by the continuous action reinforcement learning automata (CARLA), and then the corresponding parameters could be estimated in the end. Moreover, the proposed method could be applied to time-varying systems online due to its online learning ability. The simulation results suggest that the presented approach can meet the requirement of identification accuracy in both square and non-square systems.

The numerical method was used to investigate heat and moisture transport during dehydration of bananas from microwave heating. COMSOL multi-physics software was employed to perform the simulation task. A banana is defined as a porous medium. It has constituents of water, vapor, air as the liquid phase and a solid porous matrix. The numerical results of this study were validated with experimental data. The profiles of moisture, vapor and pressure are discussed in this study. Moreover, the effects of the ripening stages of the banana are examined. A higher heat flux was observed from the beginning period along with the increasing time steps until 50 s. Heat generation decreased during 50 s to 60 s, coinciding with a small rise in temperature, but the temperature gradient remained constant. The temperature distribution of both unripe and ripe banana samples was non-uniform. At the center of the banana, the temperature increased rapidly and reached its highest temperature with the negative... [more]

In the last few years, the use of ionic liquid-based membranes has gained importance in a wide variety of separation processes due to the unique properties of ionic liquids. The aim of this work is to analyze the transport of nutrients through polymer inclusion membranes based on different concentrations of methyltrioctylammonium chloride, in order to broaden the application range of these kinds of membranes. Calcium chloride (CaCl2) and sodium hydrogen phosphate (Na2HPO4) nutrients were used at the concentration of 1 g·L−1 in the feeding phase. The evolution of the concentration in the receiving phase over time (168 h) was monitored and the experimental data fitted to a diffusion-solution transport model. The results show very low permeation values for CaCl2. By contrast, in the case of Na2HPO4 the permeation values were higher and increase as the amount of ionic liquid in the membrane also increases. The surface of the membranes was characterized before and after being used in the se... [more]

Due to environmental considerations, environmental sustainability has become the main target of contemporary organizations, which has a direct influence on increasing their performance. The purpose of this study was to present the efficiency of green business process optimization for the performances of mining entities. Quantitative research was carried out on a sample of 209 people in an economic entity in the mining industry. The results of the study indicated real possibilities to achieve the objectives set in the research undertaken. Using business process management, the authors examined how green business processes can be optimized in a Romanian mining entity. The main results determined the degree of pollution from suspended and sedimentary dust particles due to coal production from the mining entity that was studied. Moreover, the present research proved that certain key environmental indicators underlie the performance and optimization of green business processes. The practica... [more]

With the increasing use of Computational Fluid Dynamics to investigate multiphase flow scenarios, modelling surface tension effects has been a topic of active research. A well known associated problem is the generation of spurious velocities (or currents), arising due to inaccuracies in calculations of the surface tension force. These spurious currents cause nonphysical flows which can adversely affect the predictive capability of these simulations. In this paper, we implement the Continuum Surface Force (CSF), Smoothed CSF and Sharp Surface Force (SSF) models in OpenFOAM. The models were validated for various multiphase flow scenarios for Capillary numbers of 10 − 3 −10. All the surface tension models provide reasonable agreement with benchmarking data for rising bubble simulations. Both CSF and SSF models successfully predicted the capillary rise between two parallel plates, but Smoothed CSF could not provide reliable results. The evolution of spurious current were studied f... [more]

In the current research, a high-pressure submerged cavitation jet is investigated numerically. A cavitation model is created considering the effect of shear stress on cavitation formation. As such, this model is developed to predict the cavitation jet, and then the numerical results are validated by high-speed photography experiment. The turbulence viscosity of the renormalization group (RNG) k-ε turbulence model is used to provide a flow field for the cavitation model. Furthermore, this model is modified using a filter-based density correction model (FBDCM). The characteristics of the convergent-divergent cavitation nozzle are investigated in detail using the current CFD simulation method. It is found that shear stress plays an important role in the cavitation formation in the high-pressure submerged jet. In the result predicted by the Zwart-Gerber-Belamri (ZGB) cavitation model, where critical static pressure is used for the threshold of cavitation inception, the cavitation bubble on... [more]

This paper proposes a perturbation estimation-based nonlinear adaptive control (NAC) for a voltage-source converter-based high voltage direct current (VSC-HVDC) system which is applied to interconnect offshore large-scale wind farms to the onshore main grid in order to enhance the fault ride-through (FRT) capability of Type-4 wind energy conversion systems (WECS). The VSC-HVDC power transmission system is regraded as a favourable solution for interconnecting offshore wind farms. To improve the FRT capability of offshore power plants, a de-loading strategy is investigated with novel advanced control of the VSC-HVDC systems. The proposed NAC does not require an accurate and precise model and full state measurements since the combinatorial effects of nonlinearities, system parameter uncertainties, and external disturbances are aggregated into a perturbation term, which are estimated by a high-gain perturbation observer (HGPO) and fully compensated for. As the proposed NAC is adaptive to s... [more]

Numerous laboratory tests are used to determine the appropriateness of new formulations in the development process in the paint and coatings industry. New formulations are most often functionally inadequate, unacceptable for environmental or health reasons, or too expensive. Formulators are obliged to repeat laboratory tests until one of the formulations fulfills the minimum requirements. This is cumbersome, slow, and expensive, and can cause ecological problems, wasting materials on tests that do not produce the desired results. The purpose of this research was to find out if there might be a better way forward to increase efficiency and free up formulators to focus on new products. In this experiment, a new paints and coatings development process was redesigned based on the potential benefits of formulation digitalization. Instead of laboratory testing, a digital platform was used that has been developed and stocked with relevant, up-to-date, and complete, usable data. This study fou... [more]

The structures and electronic properties of monolayer arsenene doped with Al, B, S and Si have been investigated based on first-principles calculation. The dopants have great influences on the properties of the monolayer arsenene. The electronic properties of the substrate are effectively tuned by substitutional doping. After doping, NO adsorbed on four kinds of substrates were investigated. The results demonstrate that NO exhibits a chemisorption character on Al-, B- and Si-doped arsenene while a physisorption character on S-doped arsenene with moderate adsorption energy. Due to the adsorption of NO, the band structures of the four systems have great changes. It reduces the energy gap of Al- and B-doped arsenene and opens the energy gap of S- and Si-doped arsenene. The large charge depletion between the NO molecule and the dopant demonstrates that there is a strong hybridization of orbitals at the surface of the doped substrate because of the formation of a covalent bond, except for S... [more]

Digital twins are rigorous mathematical models that can be used to represent the operation of real systems. This connection allows for deeper understanding of the actual states of the analyzed system through estimation of variables that are difficult to measure otherwise. In this context, the present manuscript describes the successful implementation of a digital twin to represent a four-stage multi-effect evaporation train from an industrial sugar-cane processing unit. Particularly, the complex phenomenological effects, including the coupling between thermodynamic and fluid dynamic effects, and the low level of instrumentation in the plant constitute major challenges for adequate process operation. For this reason, dynamic mass and energy balances were developed, implemented and validated with actual industrial data, in order to provide process information for decision-making in real time. For example, the digital twin was able to indicate failure of process sensors and to provide est... [more]

There is 0.032% cobalt and 0.56% sulfur in the cobalt-bearing V−Ti tailings in the Panxi Region, with the metal sulfide minerals mainly including FeS2, Fe1−xS, Co3S4, and (Fe,Co)S2, and the gangue minerals mainly including aluminosilicate minerals. The flotation process was used to recover cobalt and sulfur in the cobalt-bearing V−Ti tailings. The results showed that an optimized cobalt−sulfur concentrate with a cobalt grade of 2.08%, sulfur content of 36.12%, sulfur recovery of 85.79%, and cobalt recovery and 84.77% were obtained by flotation process of one roughing, three sweeping, and three cleaning under roughing conditions, which employed pulp pH of 8, grinding fineness of <0.074 mm occupying 80%, flotation concentration of 30%, and dosages of butyl xanthate, copper sulfate, and pine oil of 100 g/t, 30 g/t, and 20 g/t, respectively. Optimized one sweeping, two sweeping, and three sweeping conditions used a pulp pH of 9, and dosages of butyl xanthate, copper sulfate, and pine oi... [more]

The development of algorithms and methods for modelling flowsheets in the field of granular materials has a number of challenges. The difficulties are mainly related to the inhomogeneity of solid materials, requiring a description of granular materials using distributed parameters. To overcome some of these problems, an approach with transformation matrices can be used. This allows one to quantitatively describe the material transitions between different classes in a multidimensional distributed set of parameters, making it possible to properly handle dependent distributions. This contribution proposes a new method for formulating transformation matrices using population balance equations (PBE) for agglomeration and milling processes. The finite volume method for spatial discretization and the second-order Runge−Kutta method were used to obtain the complete discretized form of the PBE and to calculate the transformation matrices. The proposed method was implemented in the flowsheet mod... [more]

Butterfly pea (Clitoria ternatea L.) is a traditional medicinal and edible herb, whose health-promoting benefits have been attributed to its phenolic constituents. In this study, the effects of enzymatic hydrolysis on total phenolic content (TPC) and total flavonoid content (TFC), antioxidant (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP)) and antibacterial activities of raw and roasted (200 °C, 10−20 min) butterfly pea seeds were investigated. Roasting reduced the yield of seed aqueous extracts, but it increased the TPC and FRAP values, hence the reducing ability, of the extracts. Bromelain hydrolysis enhanced the TPC and TFC of the roasted seeds up to 2- and 18-fold higher, respectively. Trypsin hydrolysis drastically increased the TPC, but not TFC, of roasted seeds; trypsin-hydrolyzed, 20 min roasted sample had the highest TPC (54.07 μg gallic acid equivalent (GAE)/mg... [more]

In recent years, thermal processing systems with integrated temperature control have been increasingly needed to achieve high quality and high performance. In this paper, responding to the growing demands for proper transient response and to provide more accurate temperature controls, a novel slow-mode-based control (SMBC) method is proposed for multi-point temperature control systems. In the proposed method, the temperature differences and the transient response of all points can be controlled and improved by making the output of the fast modes follow that of the slow mode. Both simulations and experiments were carried out, and the results were compared to conventional control methods in order to verify the effectiveness of the proposed method.

This paper presents an analysis of the changes in interfacial surface and the size of droplets formed in a spray tower. The interfacial surface and the size of droplets formed are of fundamental importance to the performance of the equipment, both in terms of pressure drop and process efficiency. Liquid film and droplet sizes were measured using a microphotography technique. The confusors studied were classical, with profiled inside surface, and with double profiled inside surface. The liquids studied were water and aqueous solutions of high-molecular polyacrylamide (PAA) of power-law characteristics. The ranges of process Reynolds number studied were as follows: ReG ∈ (42,700; 113,000), ReL ∈ (170; 15,200). A dimensionless correlation for reduced Sauter mean diameter is proposed.

Improving water quality is a relevant environmental aspect, and using constructed wetlands (CWs) is a sustainable option for this; both porous material filled cells and plants that collectively remove contaminants must be readily available and inexpensive. This study evaluated CWs and their functionality by comparing two ornamental plants (Spathiphyllum wallisii and Hedychium coronarium) planted in experimental mesocosm units filled with layers of porous river rock, tepezil, and soil, or in mesocosms with layers of porous river rock, and tepezil, without the presence of soil. The findings during the experiments (180 days), showed that the removal of pollutants (chemical oxygen demand (COD), total solids suspended (TSS), nitrogen as ammonium (N-NH4), as nitrate (N-NO3), and phosphate (P-PO4) was 20−50% higher in mesocosms with vegetation that in the absence of this, and those mesocosms with the soil layer between 33−45% favored removal of P-PO4. Differences regarding of vegetation remov... [more]