As enterprises pay more and more attention to environmental issues, the green supply chain management (GSCM) mode has been extensively utilized to guarantee profit and sustainable development. Green supplier selection (GSS), which is a key segment of GSCM, has been investigated to put forward plenty of GSS approaches. At present, enterprises prefer to construct the large-scale teams of decision makers to obtain the more reasonable ranking results during GSS process. However, the existing methods pay little attention to the large-scale GSS procedure. To investigate the GSS issue with a large-scale group of decision makers, a new GSS approach under a q-rung interval-valued orthopair fuzzy environment is developed. The q-rung interval-valued orthopair fuzzy numbers are introduced to describe the evaluation information of green suppliers. Combined with a clustering approach and several clustering principles, the large-scale decision makers are divided into several subgroups. Next, the simi... [more]

Eutrophication is an inevitable phenomenon, and it has recently become an unabated threat. As a positive, the thriving microalgal biomass in eutrophic water is conventionally perceived to be loaded with myriad valuable biochemical compounds. Therefore, a sugarcane-bagasse-based adsorbent was proposed in this study to harvest the microalgal biomass for producing biodiesel. By activating the sugarcane-bagasse-based adsorbent with 1.5 M of H2SO4, a highest adsorption capacity of 108.9 ± 0.3 mg/g was attained. This was fundamentally due to the surface potential of the 1.5 M H2SO4 acid-modified sugarcane-bagasse-based adsorbent possessing the lowest surface positivity value as calculated from its point of zero charge. The adsorption capacity was then improved to 192.9 ± 0.1 mg/g by stepwise optimizing the adsorbent size to 6.7−8.0 mm, adsorption medium pH to 2−4, and adsorbent dosage to 0.4 g per 100 mL of adsorption medium. This resulted in 91.5% microalgae removal efficiency. Excellent-qu... [more]

The diffusion coefficient of gases in coal varies with time. This study aims to develop an unsteady dynamic diffusion (UDD) model based on the decay of diffusion coefficient with time and the change of integral. This study conducted a series of gas desorption and diffusion experiments with three different combinations of particle sizes and gas pressures and compared the diffusion coefficients of the three models. The UDD model exhibited good fitting results, and both the UDD and bidisperse models fitted the experimental data better than the unipore model. In addition, the dynamic diffusion coefficient (DDe) decreased rapidly in the initial stage but gradually decreased to a stable level in the later stage. All the effective diffusion coefficients of the three models negatively correlated with the particle size. In the unipore model, the diffusion coefficient of coal samples with three particle sizes increased with gas pressure. In the bidisperse and UDD models, the diffusion coefficien... [more]

By integrating gas, electricity, and cooling and heat networks, multi-energy system (MES) breaks the bondage of isolated planning and operation of independent energy systems. Appropriate scheduling of MES is critical to the operational economy, and it is essential to design scheduling strategies to achieve maximum economic benefits. In addition to the emergence of energy conversion systems, the other main novelty of MES is the multivariate of load, which offers a great optimization potential by changing load replaceability (flexibly adjusting the composition of loads). In this paper, by designing load replaceability index (LRI) of composite load in MES, its interaction mechanism with scheduling optimum is systematically analyzed. Through case studies, it is proven that the optimum can be improved by elevating load replaceability.

Pipeline end termination (PLET) installation is an essential part of offshore pipe-laying operation. Pipe-laying operations are sensitive to pipe-laying barge motion and marine environmental conditions. Monitoring the field environment can provide a reasonable basis for planning pipe-laying. Therefore, the measurement and analysis of sea wave motion is helpful for the control and operational safety of the pipeline and vessels. In this study, an environmental monitoring system was established to measure wave motion during PLET operation. Fourier transforms were used to process images that were acquired by ultra-high-frequency X-band marine radar to extract wave parameters. The resulting wave spectra, as measured each minute, were used to simulate real-time wave data and calculate wave characteristics and regressed wave frequency and direction spectrum throughout the PLET operation. The regressed frequency, spectral density, and direction spectra were compared with the theoretical spectr... [more]

It is significant to analyze the blend homogeneity of cohesive powders during pharmaceutical manufacturing in order to provide the exact content of the active pharmaceutical ingredient (API) for each individual dose unit. In this paper, an online monitoring platform using an MEMS near infrared (NIR) sensor was designed to control the bin blending process of cohesive powders. The state of blend homogeneity was detected by an adaptive algorithm, which was calibration free. The online control procedures and algorithm’s parameters were fine-tuned through six pilot experiments and were successfully transferred to the industrial production. The reliability of homogeneity detection results was validated by 16 commercial scale experiments using 16 kinds of natural product powders (NPPs), respectively. Furthermore, 19 physical quality attributes of all NPPs and the excipient were fully characterized. The blending end time was used to denote the degree of difficulty of blending. The empirical re... [more]

The ecological efficiency (EE) of the remanufacturing process occupies an important position in the whole index system of remanufacturing because it will directly affect the economic and environmental benefits of remanufacturing. Therefore, in order to study the EE of the remanufacturing process, a method is proposed to optimize and evaluate the EE of the remanufacturing process. In this method, firstly, the original remanufacturing sub-schemes of used components are designed according to the extracted fault characteristics; secondly, a set of optional process schemes are integrated by using directed graph (DG) to reduce the process schemes; thirdly, the objective function of EE is established, and then an ant colony algorithm with elite strategy (ES-ACO) is proposed to optimize the process schemes. After obtaining the optimal value of EE, the quality coefficient of used components can be calculated, and then numerical simulations (NS) are used to analyze the correlation between the qu... [more]

Given that the equipment for the semiconductor packaging line adopts the fixed grouping production method, thus failing to dynamically match the processing task demand capacity, in the present study, we proposed a semiconductor bonding equipment-grouping method based on processing task matching. This method sets the device group closed position constraint and the matching constraint between the device type and the processing type and uses the graph theory method to establish the device grouping model. The dynamic grouping of equipment under the capacity demand of different processing tasks was achieved by changing the relationship matrix between devices. The drawback of this grouping method is rather large grouping deviation, which we tried to solve with the clustering by fast search and find of density peaks (CFSFDP) that was added to cluster the sets of attribute information of the devices so as to obtain the maximum number of grouping groups obtained to reduce the grouping deviation... [more]

The result of an adsorption experiment indicated that the pure magadiite (MAG) and the modified MAG via cetyltrimethylammonium-bromide (CTAB-MAG) possessed pronounced affinity to the Rhodamine-B (Rh-B) dye molecules. CTAB-MAG was synthesized with an ion-exchange method between MAG and cetyltrimethylammonium-bromide (CTAB) in an aqueous solution. The adsorption capacities of CTAB-MAG and MAG on Rh-B were 67.19 mg/g and 48.13 mg/g, respectively; while the pH and the time were 7 and 60 min, respectively; however, the initial concentration of Rh-B was 100 mg/L, and adsorbent dosage was 1 g/L. Whereas, the adsorption capacity of CTAB-MAG was increased by 40% over MAG which indicated that CTAB-MAG can be used as an efficient low-cost adsorbent. Adsorption kinetics were consistent with the pseudo-second-order kinetic equation; the adsorption processes were dominated by film diffusion process which belonged to monomolecular layer adsorption.

Spray cooling with liquid nitrogen is increasingly utilized as an efficient approach to achieve cryogenic cooling. Effects of injection mass flow rate fluctuations on the evaporation, temperature distribution, and droplet distribution of a spray field were examined by employing a validated Computational Fluid Dynamics (CFD) numerical model. The numerical results indicated that injection fluctuations enhanced the volume-averaging turbulent kinetic energy and promoted the evaporation of the whole spray field. The strengthened mass and heat transfer between the liquid nitrogen droplets and the surrounding vapor created by the fluctuating injection led to a lower temperature of the whole volume. A relatively smaller droplet size and a more inhomogeneous droplet distribution were obtained under the unsteady inlet. The changes of the frequency and the amplitude of the fluctuations had little effects on the overall spray development. The results could enrich the knowledge of the relation betw... [more]

The compact finite difference scheme on non-uniform meshes and the Fourier spectral hybrid method are used to directly simulate the evolution of vortex structures in a laminar boundary layer over a flat plate. To this end, two initial local vibration disturbances, namely, the positive−negative and the negative−positive models, at the wall were adopted. The numerical results show that the maximum amplitudes of vortex structures experience a process of linear growth and nonlinear rapid growth. The vertical disturbance velocity and mean flow shear and the derivative term of the stream-wise disturbance velocity and the span-wise disturbance velocity, are important factors for vortex structure development; the high- and low-speed stripe and the stream-wise vortex are consistent with structures seen in full turbulence. The maximum amplitude of the negative−positive model grows more quickly than that of the negative−positive model, and the detailed vortex structures are different for the two... [more]

The lumpy zone in a blast furnace is composed of piles formed naturally during burden charging. The properties of this zone have significant effects on the blast furnace operation, including heat and mass transfer, chemical reactions and gas flow. The properties of the layers mainly include the angle of repose and porosity distribution. This paper introduces two methods, the Discharging Method and the Lifting Method, to study the influence of the packing method on the angle of repose of the pile. The relationships of the angle of repose and porosity with physical parameters are also investigated. The porosity distribution in the bottom of a pile shows a decreasing trend from the region below the apex to the center. The coordination number of the particles is employed to explain this change. The maximum of the frequency distribution of it was found to show a negative correlation to the static friction coefficient, but becomes insensitive to the parameter as the static friction coefficie... [more]

Spray drying is a key unit operation used to achieve particulate products of required properties. Despite its widespread use, the product and process design, as well as the process control remain highly empirical and depend on trial and error experiments. Studying the effect of operational parameters experimentally is tedious, time consuming, and expensive. In this paper, we carry out a model-based global sensitivity analysis (GSA) of the process. Such an exercise allows us to quantify the impact of different process parameters, many of which interact with each other, on the product properties and conditions that have an impact on the functionality of the final drug product. Moreover, classical sensitivity analysis using the Sobol-based sensitivity indices was supplemented by a polynomial chaos-based sensitivity analysis, which proved to be an efficient method to reduce the computational cost of the GSA. The results obtained demonstrate the different response dependencies of the studie... [more]

There is a significant interest in valorizing swine manure that is produced in enormous quantities. Therefore, considering the high moisture content in swine manure, the objective of this research was to convert manure slurry into hydrochars via hydrothermal carbonization and analyze the yields, pH, energy contents, and thermal and oxidation kinetic parameters. Experiments were performed in triplicate in 250 mL kettle reactors lined with polypropylene at 180 °C, 200 °C, 240 °C, 220 °C, and 260 °C for 24 h. Analyses of the results indicated that the process temperature affected the hydrochar yields, with yield generally decreasing with increasing temperature, but it had little effect on the composition of the hydrochar. The hydrochars were found to have higher volatile contents and H/C and O/C ratios and about 85% of the energy compared to coal. However, the presence of high fraction (35−38%) of ash in hydrochars is a serious concern and needs to be addressed before the complete utiliza... [more]

Nanofiltration of aqueous solutions of succinic acid with the addition of sodium hydroxide or magnesium hydroxycarbonate has been investigated experimentally and modeled with the comprehensively described Donnan−Steric partitioning model. The experimental retentions of acid at the same pH varied between 16% and 78%, while the estimated total volume membrane charge densities were in the range of −35.73 and +875.69 mol/m3. This work presents a novel insight into the modeling of nanofiltration and investigates the relations between the estimated total volume membrane charge densities, ionic strength, and component concentration on the performance of ceramic membrane. In addition, this study takes into consideration other parameters such as pH regulation and viscosities of solutions.

Pore network models are powerful tools to simulate invasion and transport processes in porous media. They are widely applied in the field of geology and the drying of porous media, and have recently also received attention in fuel cell applications. Here we want to describe and discuss how pore network models can be used as a prescriptive tool for future water electrolysis technologies. In detail, we suggest in a first approach a pore network model of drainage for the prediction of the oxygen and water invasion process inside the anodic porous transport layer at high current densities. We neglect wetting liquid films and show that, in this situation, numerous isolated liquid clusters develop when oxygen invades the pore network. In the simulation with narrow pore size distribution, the volumetric ratio of the liquid transporting clusters connected between the catalyst layer and the water supply channel is only around 3% of the total liquid volume contained inside the pore network at th... [more]

A significant challenge in the utilization of alternative gaseous fuels is to use their energy potential at the desired location, considering economic feasibility and sustainability. A potential solution is a compression, transportation in pressure tanks, and generation of electricity and heat directly at the recipient. In this research, the potential for generating syngas from abundant waste substrates was analyzed. The sewage sludge (SS) was used as an example of a bulky and abundant resource that could be valorized via gasification, compression, and transport to end-users in containers. A model was developed, and theoretical analyses were completed to examine the influence of the calorific value of the syngas produced from the SS gasification (under different temperatures and gasifying agents) on the efficiency of energy transportation of compressed syngas. First, the gasification simulation was carried out, assuming equilibrium in a downdraft gasifier (reactor) from 973−1473 K and... [more]

This paper proposes a novel computationally efficient, easy-to-implement electromagnetic hysteresis based dynamics model of a kind of intelligent electromagnetic torque controlled coupling (EMTC), which, with drag torque under consideration, first models the electromagnetic hysteresis existing in the primary clutch with the classical Preisach model, and then models the transferred torques in the three friction elements of the center coupling in the slipping and locked modes, respectively. The performance of the model is verified by simulation and experiment jointly, which lays the basis for the development of advanced control algorithm.

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]