In the Supercritical Antisolvent process (SAS), the thermodynamic behavior of complex multicomponent systems can influence the particles’ morphology. However, due to the limited thermodynamic data for multicomponent systems, the effect of solutes is often neglected, and the system is considered as pseudo-binary. It has been demonstrated that the presence of a solute can significantly influence the thermodynamic behavior of the system. In particular, when the SAS process is adopted for the production of drug/polymer coprecipitated microparticles, the effect of both the drug and the polymer in the solvent/CO2 mixture should be considered. In this work, the effect of polyvinylpyrrolidone (PVP), used as the carrier, and of the liposoluble vitamins menadione (MEN) and α-tocopherol (TOC), as model drugs, was investigated as a deviation from the fundamental thermodynamic behavior of the DMSO/CO2 binary system. Vapor−liquid equilibria (VLE) were evaluated at 313 K, with a PVP concentration in... [more]

The high chloride content of municipal solid waste incineration (MSWI) fly ash and hazardous waste incineration (HWI) fly ash has considerably affected their disposal. This study focused on investigating the three-stage counter-current (TSC) water-washing process to reduce the chlorine content efficiently under the premise of low water consumption. The liquid−solid ratio (LSR) and washing time were investigated, a chloride migration model was established, and the characteristics of the water-washing solution (WWS) and washed fly ash were investigated. The results showed that the dechlorination effect of TSC washing could reach more than 99% in a low liquid−solid ratio (LSR) of 2−4 kg/L. The most appropriate LSR and washing time were found to be around 3:1 L/kg and 15 min per stage, respectively. The concentration of Cl− in WWS reached over 90 g/L, which is very high among industrial saline wastewater. Some heavy metals were also contained in the WWS, and lead was the main heavy metal,... [more]

Because of its anticancer, anti-inflammatory, and antibiotic properties, berberine has been used extensively in medication. The extensive production of berberine results in the generation of wastewater containing concentrated residual berberine. However, to date, limited related studies on the biological treatment of berberine wastewaters have been carried out. A lab-scale anaerobic baffled reactor (ABR)−aerobic granular sludge (AGS) process was developed for berberine removal from synthetic wastewater. The system showed effective removal of the berberine. In order to better understand the roles of the bacterial community, the ABR−aerobic granular sludge system was operated in the state with the highest BBR removal rate in this study. The bacterial community dynamics were studied using the 16S rDNA clone library. The results showed that the hybrid ABR-AGS process achieved 92.2% and 94.8% overall removals of berberine and COD, respectively. Bacterium was dominant species in ABR, while t... [more]

In order to find an efficient and economical wetland substrate to treat mine wastewater containing various heavy metals, and effectively realize the resource utilization of water treatment residuals, in this paper, the treatment efficiency of mine wastewater containing various heavy metals was investigated using unburned ceramsite prepared from water treatment residuals (UCWTR) and clay ceramsite. The continuous dynamic test results showed that the removal rate of Pb, Cd, Cu, Zn, and Fe can reach more than 98.5% after the UCWTR-based CWs runs for 56 days, and its concentration was 30.05%, 24.85%, 20.82%, 14.63%, and 7.91% lower than that of the clay ceramsite-based CWs, respectively. SEM, XPS, and FT-IR showed that the characteristic peaks of two ceramsites were basically similar. The ceramsite undergoes ion exchange, coordination complexation, and chelation reaction with Pb, Cd, Cu, Zn, and Fe under the action of the gel of internal groups -OH, C=O, Al-OH, Si-Fe-O and C-S-H. Compared... [more]

Approach for the description of chemical equilibrium shifts in the systems with free and connected chemical reactions was elaborated. Driving forces of chemical equilibrium shifts were temperature change (at P = const), pressure change (at T = const), and input or output of reagents or products (at T, P = const). It was demonstrated how the conditions for passing through the extremes of the state parameters (T, P, and components molar numbers) in one of the reactions transmitted to other reactions, connected with the first one by reagents or products.

In this paper, the effects of blade trailing edge (TE) profile modification of the suction side on the internal flow and hydraulic performance in a low-specific speed centrifugal pump are investigated through particle image velocimetry (PIV) analysis. Three impellers with different blade trailing edge profiles named original trailing edge (OTE), arc trailing edge 1 (ATE1), and arc trailing edge 2 (ATE2) are designed for PIV experiments. Results show that blade trailing edge modification of the suction side can significantly change the flow pattern, affecting the hydraulic performance of the model pumps. There is a definite counterclockwise backflow vortex near the suction side of OTE at deep-low flow rate, resulting in a decrease in the uniformity of the flow field at the outlet and the hydraulic performance. ATE1 with a reasonable larger blade outlet angle has the best flow field, and the head and efficiency are increased by about 1.2% and 8%, respectively under the same working condi... [more]

The objective of this study was to evaluate the impact of high intensity ultrasound (HIU)-assisted brining on the physicochemical characteristics and consumer preference of smoked pork loin (Longissimus dorsi, LD). LD cuts (5 × 8 × 2.5 cm, length × width × height) were randomly distributed in a 2 × 2 design of two concentration of brine (5 or 10% NaCl) and two methods of brining (static, TC; or HIU for 30 min). After brining, the samples were smoked, cooled, vacuum packed and stored for 7 d at 4 °C. Weight, pH, percentage of NaCl, water-holding capacity (WHC), shear force and colour characteristics were evaluated in post-brining and smoked samples. Sensory analysis was performed to evaluate preference in appearance, taste, and texture characteristics. Weight and NaCl increased in samples post-brining. However, smoked pork samples were not significantly different among treatments. The smoked samples became more yellow and less red. Consumers preferred TC smoked pork based on this appear... [more]

This paper presents the circuit and control method for piezo-ceramic drives. With the proposed method, a gap is imposed in the transformer core to increase the leakage inductance. This flattens the voltage gain curve of the piezo-ceramic driver over the resonant frequency range, so voltage gain changes are insensitive to frequency changes. In addition, resonant frequency tracking and power control methods are developed, while the circuit is capable of zero-voltage soft-switching such that the circuit operation efficiency can be improved. In order to solidify the practicality of the circuit design, mathematical analysis and experimental validations have been thoroughly performed. The test results help to confirm the effectiveness of the proposed method and demonstrate its practicality in industrial applications.

Due to issues such as heat accumulation, the site area, and project investment, the reasonable determination of the hole spacing for heat exchangers has become one of the key design points of the ground-coupled heat pump system. Based on the definition of heat penetration in heat transfer and the research method of the inverse problem, a direct algorithm of the heat penetration distance in the aquifer was proposed using the analytical solution to the mathematical model for one-dimensional heat convection−conduction problems. Taking a vertical ground-coupled heat pump project in Hefei, Anhui Province, China, as an example, a three-dimensional hydro-thermal coupling numerical simulation model was established, and the influence radius during the refrigeration and heating periods under the action of a single borehole heat exchanger was determined. Comparing the heat penetration distance with the influence radius, the results show that the relative errors of the results obtained by the two... [more]

This study represents a first time that perstraction was assessed as a process to remove perfluorooctanoic acid (PFOA) from water. In the perstraction process, PFOA permeates through a membrane from water to a solvent. The membrane used in this study was polydimethylsiloxane (PDMS). The experimental approach included the following: (1) measurement of partition coefficients for PFOA between water and selected solvents; (2) determination of solubility and diffusivity of the solvents in PDMS; (3) determination of the uptake of PFOA in PDMS; (4) determination of the effects of selected particles imbedded in the PDMS on PFOA uptake and solvent absorption; and (5) demonstration of the perstraction process to remove PFOA from water. PFOA preferentially partitioned to alcohols over water. In addition, ZnO and CuO particles in PDMS significantly enhanced the rate at which PFOA was absorbed in PDMS from deionized water due to ionic interactions. The perstraction of PFOA from deionized water into... [more]

Producing highly efficient electric motors remains a challenge nowadays. Given that the legislation in the field requires the transition to the production of engines with increased efficiency, for manufacturing companies, switching from one generation of engines to another can be a difficult task. This paper analyzes ways to adapt the assembly of engines of the IE4 generation starting from the assembly lines of the engines of the previous generation, IE3. The analysis of the assembly process covers both the operator training part and the actual assembly part. Ten possible variants for the assembly line and specific decisional variables have been defined. The decision to choose the optimal assembly configuration was made using as management tools the matrix of consequences and utilities. The validation of the theoretical model of the assembly line was carried out through a case study built for two classes of electric motors, namely G90 and G180. For a total production of IE4 electric mo... [more]

This study attempts to optimize the arc-shaped coned disk affecting the uniformity of the earlier designed fertilizer apparatus (FA), in particular, for application in the rice−oil rotation region in the middle and lower reaches of the Yangtze River, China. Based on theoretical analysis, a circular coned disk with the curvature gradual decline (GD) from top to bottom was designed, and the equation of the circular cone was determined. The EDEM discrete element software was used, using the coefficient of variation of the fertilization amount consistency in every row, the coefficient of variation of the fertilization amount stability, and the coefficient of variation of the fertilization amount consistency in the same row as evaluation indices. Simulations and comparative tests of FA performance were performed for three cases of the busbar top-to-bottom curvature variation: (i) gradual increase (GI), (ii) gradual decline (GD), and (iii) zero (0) variation. The experimental results show th... [more]

In order to investigate the explosion mechanism of sucrose in the air atmosphere, the explosion intensity under different ignition delay times (IDT), powder input pressures (PIP), and concentrations were studied using a 20L-sphere. The sucrose particles were analyzed in a synchronized thermal analyzer (STA) and scanning electron microscope (SEM). The results are as follows: 1. The DSC curve has two endothermic peaks and one exothermic peak, respectively at T = 180.5 ℃, 510.2 ℃ and 582.6 ℃. 2. The explosion intensity varies with the experiment conditions. The maximum explosion pressure (Pmax) appears when IDT = 90 ms, PIP = 1.5 MPa and concentration = 625 g/m3. 3. The explosive mechanism is a homogeneous combustion mechanism based on particle surface pyrolysis and volatilization. Because of the decomposition, H2, CO, furfural, and other flammable gas-phase products are released, then surface burn appears, which leads to the crystal rupture on account of thermal imbalance, resulting in m... [more]

The most common scale-up approach for gas−solids fluidized beds is based on matching the governing dimensionless parameters. In the literature, this approach has been validated only by means of measuring global parameters between different sizes of fluidized beds. However, such global measurements are not sufficient to depict all the interplaying hydrodynamic phenomena and hence verify the scale-up relationships. Therefore, to assess this approach, an advanced gas−solids optical probe and pressure transducer measurement techniques have been applied to quantify local hydrodynamic parameters in two different sized fluidized beds. Four different sets of experimental conditions were designed and conducted to examine the assessment of the scaling approach with matched and mismatched dimensionless groups between the two beds. The results indicated that the reported dimensionless groups are not adequate for achieving similarity between the two gas−solids fluidized beds in terms of solids hold... [more]

In a wide range of applications, heating or cooling systems provide not only temperature changes, but also small temperature gradients in a sample or industrial facility. Although a conventional proportional-integral-derivative (PID) controller usually solves the problem, it is not optimal because it does not use information about the main sources of change—the current power of the heater or cooler. The quality of control can be significantly improved by including a model of thermal processes in the control algorithm. Although the temperature distribution in the device can be calculated from a full-fledged 3D model based on partial differential equations, this approach has at least two drawbacks: the presence of many difficult-to-determine parameters and excessive complexity for control tasks. The development of a simplified mathematical model, free from these shortcomings, makes it possible to significantly improve the quality of control. The development of such a model using generati... [more]

Conventional design method of the downhole tractor is based on cementing casing, which is only suitable for the smooth wellbore. For the open hole well, the conventional downhole tractor has poor adaptability and even cannot work normally. In order to improve the obstacle surmounting performance of the wheeled downhole tractor (WDR) and expand the application range of the WDR, a double push rod-double spring support adjustment mechanism (DPRDSSAM) is proposed in this paper. Meanwhile, the proposed DPRDSSAM also needs to increase the traction force and the stability of the WDR in the open hole well. Kinematic simulation numerical models of both conventional support adjustment mechanism and the DPRDSSAM are established. The two models comprehensively considere the influence of different obstacle forms and sizes on the obstacle surmounting performance of the tractor. The influence of different obstacle forms on the obstacle surmounting performance of DPRDSSAM and single push rod support a... [more]

Jerusalem artichoke (Helianthus tuberosus L.) is emerging as one of the energy plants considered for biofuel production. Alkali and alkali-involved pretreatment methods have been widely used for the bioconversion of cellulosic materials due to their high sugar yield and low inhibitor release. However, the recovery and treatment of wastewater (black liquor) have been poorly studied. Here, we present a novel two-stage pretreatment process design for recycling black liquor. Jerusalem artichoke stalk (JAS) was first treated with 2% (w/v) NaOH, after which lignin was recovered by H2SO4 at pH 2.0 from the black liquor. The recycled solutions were subsequently used to treat the NaOH-pretreated JAS for the second time to dissolve hemicellulose. CO-pretreated JAS, hydrolysates, and acid-insoluble lignin were obtained after the above-mentioned two-stage pretreatment. A reducing sugar yield of 809.98 mg/g Co-pretreated JAS was achieved after 48 h at 5% substrate concentration using a cellulase do... [more]

Metal manufacturing processes are essential techniques to convert raw materials into desired metal products, which contributes significantly to the growth of industry and our society [...]

Extensive research has been carried out to figure out safe means of disposing various industrial effluents. Industrial wastewaters from the aeration industry such as heavy metals and oily substances contain a high degree of contamination. The advanced oxidation process is one of the most effective and rapid methods of removing contaminations, which can lead to a high chemical oxygen demand (COD). The aim of the present study is to reduce the COD of an aeration effluent with the initial COD of 13,004 mg/L. About 20 sets of experimental tests were conducted to identify the contribution of H2O2, O3, and UV to the treatment process. The influence of the quantities of additives and the dose of the UV irradiance were, too, among the subjects of the study. These factors were altered throughout the experiments and their mutual effects were measured. To design the experiments, Minitab software 16 was utilized. The experimental conditions were set at the standard values of 25 °C and 1 bar to min... [more]

Effects of the container design on the heat transfer rate and food quality during microwave heating were explored and validated with numerical simulations and experiments. The uniformity of moisture content and temperature was investigated, and to describe microwave heating patterns, a simulation model was created. Pork patties with different moisture and salt contents were heated in three different containers (center and edge-perforated lid as well as without lid) to achieve 80 °C using a domestic microwave oven. Compared to the center or mid-way positions, the temperatures at the edge of the patties rose quickly. By containing the evaporated vapor from the heated pork patties inside the container, the container with a center-perforated lid decreased the heating rate and non-uniformity in temperature and moisture content. A simplified numerical model for the electromagnetics, heat, and momentum transfer coupling simulation was developed to understand the moisture and temperature distr... [more]

Heavy oil and biomass co-gasification has been analyzed through a model developed in Aspen Plus™ v 11.0 software. The model was used to assess main gasification parameters, such as cold gas efficiency, yield, low heating value (LHV), and producer gas composition, using air and oxygen as gasification agents. Subsequently, producer gas energy use in the Rankine cycle was performed using a model developed in GateCycle™ v11.1.2.4.850 software. Likewise, the economic indicators of the integrated Rankine cycle-gasification system were calculated. The economic evaluation was developed through Monte Carlo simulation using Crystalball™. The results showed a LHV producer gas decreasing trend as the equivalence ratio (ER) increased, oscillating between 6.37 and 3.63 MJ/Nm3 for ER values greater than 0.30 in the air co-gasification case, while the scenario that used oxygen presented better LHV results, ranging from 9.40 to 11.79 MJ/Nm3. For air co-gasification, the Rankine cycle efficiency range w... [more]

The development of a biorefinery is described based on rapid polishing of partially treated sewage with three different species of macrophytes in the recently developed SHEFROL® bioreactor which functions almost entirely on solar and gravitational energy, requiring no chemicals. It was seen that at a hydraulic retention time (HRT) of just 2 h, suspended solids, COD, BOD, total Kjeldahl nitrogen, soluble phosphorus, zinc, copper, nickel, and manganese are reduced to the extents of 92−95%, 76−78%, 77−81%, 56−61%, 60−66%, 43−46%, 45−48%, 30−35%, and 31−33%, respectively. The treated water meets the water quality standards set for the discharge into surface water bodies. M. quadrifolia was seen to be most effective of the three macrophytes, followed by P. stratiotes and S. molesta, as a sewage cleansing agent, but the difference in the performance of the macrophytes was only marginal, and not highly significant statistically (p ≥ 0.5). The paper also shows that it is possible to extract en... [more]

Achieving curved crease surfaces is a current challenge for designers, the field still underexplored. The curve on which the bending is performed can present extremely complicated shapes that must be accurately generated through various technological processes. For this aim, a planar mechanism consisting of an ellipsograph, a conchoidograph and an RRR dyad—whose inner joint generates the targeted connecting rod curve—was proposed in this paper. Parametrizing the lengths of the elements of the RRR dyad, the correlation coefficient of the rotations of the leading elements and the directions of these movements result in different connecting rod curves, which can be used to obtain the folded surfaces; the optimization, according to various criteria, will be explored for the automatic generation of some design solutions. With the help of the Altair program, for some given geometrical data of the mechanism, both the drawing of the curve on plates of different initial shapes and the simulatio... [more]

The new generation of data centers is further evolving towards the direction of high speed and intelligence, which puts forward a great demand for the iteration of optical interconnection technology. Three-dimensional integration based on active photonic interposers can achieve the advantages of high integration, high bandwidth and low power consumption, which has become the main direction for next generation optical module technology. The fabrication and assembly of 3D optical modules based on active interposer-integrated edge couplers and TSV are realized in this paper. Different active interposer processes with integrated edge couplers and RDL-TSV-RDL structures are discussed, manufactured, analyzed and evaluated. The problem of the co-fabrication of the TSV and edge coupler was solved, and perfect electrical and optical characteristics were also achieved. Finally, the fabrication of the substrate and the assembly of the 3D optical module were completed. This paper lays a solid foun... [more]

In this study, carbon aerogels (CAs) were synthesized by the sol-gel method, using environmentally friendly glucose as a precursor, and then they were further activated with potassium hydroxide (KOH) to obtain activated carbon aerogels (ACAs). After the activation, the electrochemical performance of the ACAs was significantly improved, and the specific capacitance increased from 19.70 F·g−1 to 111.89 F·g−1. Moreover, the ACAs showed a stronger hydrophilicity with the contact angle of 118.54° compared with CAs (69.31°). When used as an electrode for capacitive deionization (CDI), the ACAs had not only a better diffuse electric double layer behavior, but also a lower charge transfer resistance and intrinsic resistance. Thus, the ACA electrode had a faster CDI desalination rate and a higher desalination capacity. The unit adsorption capacity is three times larger than that of the CA electrode. In the desalination experiment of 100 mg·L−1 sodium chloride (NaCl) solution using a CDI device... [more]