The multi-drop method with a good droplet quality is a big challenge in inkjet technology. In this study, optimization of Drop on Demand (DoD) inkjet printer waveform design was conducted. The effectiveness of the waveform design, so-called W waveform, from previous study as a preliminary vibration for the multi-drop ejection method was investigated. The unmodified W waveform was proven not to be an effective waveform for lower viscosity of liquid, especially when compared by the standard waveform obtained from a print-head manufacturer. Edible ink with a viscosity below the optimum range for print-head specifications was employed as the operating liquid. The preliminary vibration W waveform was modified to improve the droplet quality of the edible ink. It was proven that a 40% adjusted voltage of the rear wave of the W waveform was effective as the optimum waveform design for edible ink. The droplet quality of the multi-drop ejection method for grey-scale technology was improved by op... [more]

The purpose of this study was to investigate the droplet size obtained with a three-channel spray nozzle typically used in fluid bed devices and to construct a semi-empirical model for prediction of droplet size. With the aid of a custom-made optical method concept, the impact of the type of polymer and solvents used through dispersion properties (viscosity, density, and surface tension), dispersion flow rate, atomization pressure, and microclimate pressure on droplet size was investigated. A semi-empirical model with adequate predictability for calculating the average droplet size (R2 = 0.90, Q2 = 0.73) and its distribution (R2 = 0.84, Q2 = 0.61) was constructed by employing dimensional analysis and design of experiments. Newtonian and non-Newtonian dispersion and process parameters on laboratory and on production scale were included, thereby enabling constant droplet size irrespective of the scale. Based on the model results, it would be possible to scale-up the atomization process (... [more]

Remanufacturing has gained great recognition in recent years due to its economic and environmental benefits and effectiveness in the value retention of waste products. Many studies on reverse logistics have considered remanufacturing as a key node for network optimization, but few literature reviews have explicitly mentioned remanufacturing as a main feature in their analysis. The aim of this review is to bridge this gap. In total, 125 papers on remanufacturing reverse logistics network design have been reviewed and conclusions have been drawn from four aspects: (1) in terms of network structure, the functional nodes of new hybrid facilities and the network structure combined with the remanufacturing technologies of products are the key points in the research. (2) In the mathematical model, the multi-objective function considered from different aspects, the uncertainty of recovery time and recovery channel in addition to quantity and quality, and the selection of appropriate algorithms... [more]

Box girder is an important bearing and force transmitting component in the gondola car body; the rationality of its structure directly affects the life of the whole car body. In order to solve disadvantage of the traditional box girder optimization method, which mainly depends on design experience, the combined method of orthogonal experimental design and the genetic algorithm-back propagation (GA-BP) algorithm is used for the structural optimization of bolster beam in this paper. Nine groups of parameters were established by orthogonal experiment, which can give typical samples for GA-BP optimization. Then, the bolster beam is optimized by the GA-BP algorithm, and the new gondola car body model is established with the optimized parameters. The finite element analysis results show that the minimum stress is found by using the GA-BP algorithm, which is basically consistent with the simulation results. Finally, the results show that the combined method of orthogonal experimental design a... [more]

This manuscript investigates the supercritical carbon dioxide (sCO2) power cycle employed in the power block of concentrated solar power (CSP) plants—solar tower—as an alternative for solar desalination, developed with either distillation or reverse osmosis. This concept is investigated as a possible up-scaling of the SOLMIDEFF project, originally based on a hot-air micro gas turbine combined with a solar dish collector. For the upscaled concept, five different sCO2 cycles are considered, chosen amongst the best-performing configurations proposed in the literature for CSP applications, and modelled with Thermoflex software. The influence of ambient conditions is studied, considering two minimum cycle temperatures (35 °C and 50 °C), corresponding to Santa Cruz de Tenerife and Abu Dhabi, respectively. The results show that the low temperatures at the inlet of the heat rejection unit compromise the viability of distillation technologies. On the other hand, the high thermal efficiency achi... [more]

In this paper, we report a successfully modified single-crystal Si growth furnace for impurity control. Four types of arbitrary magnetic heater (AMGH) systems with 3, 4, 5, and poly parts were designed in a coil shape and analyzed using crystal growth simulation. The concentration of oxygen impurities in single-crystal Si ingots was compared among the designed AMGHs and a normal graphite heater (NGH). The designed AMGHs were confirmed to be able to control turbulence and convection in a molten state, which created a vortex that influenced the oxygen direction near the melt−crystal interface. It was confirmed that replacing NGH with AMGHs resulted in a reduction in the average oxygen concentration at the Si melt−crystal interface by approximately 4.8%.

This paper presents a novel bidirectional DC−DC converter, equipped with a three-winding coupled inductor, that can be applied to high-voltage, bidirectional DC−DC energy conversion and meet battery charging and discharging requirements. The architecture consists of a semi-Z-source converter and a forward−flyback converter featuring a three-winding coupled inductor with an iron core. This proposed topology retains the current continuity characteristics of the low-voltage side, all switches possess the zero-voltage switching feature, and the switches on the low-voltage side in the step-down mode have a synchronous rectification function. A 500-W bidirectional converter is implemented to examine the practicality and feasibility of the proposed topology. The relatively streamlined design of the converter can greatly reduce production costs. In the step-up and step-down modes, the maximum energy conversion efficiencies are 95.74% and 96.13%, respectively.

This paper develops a Takagi-Sugeno fuzzy observer gain design algorithm to estimate ship motion based on Automatic Identification System (AIS) data. Nowadays, AIS data is widely applied in the maritime field. To solve the problem of safety, it is necessary to accurately estimate the trajectory of ships. Firstly, a nonlinear ship dynamic system is considered to represent the dynamic behaviors of ships. In the literature, nonlinear observer design methods have been studied to estimate the ship path based on AIS data. However, the nonlinear observer design method is challenging to create directly since some dynamic ship systems are more complex. This paper represents nonlinear ship dynamic systems by the Takagi-Sugeno fuzzy model. Based on the Takagi-Sugeno fuzzy model, a fuzzy observer design method is developed to solve the problem of estimating using AIS data. Moreover, the observer gains of the fuzzy observer can be adjusted systemically by a novel algorithm. Via the proposed algorit... [more]

Polyhydroxyalkanoates (PHA) are a family of biodegradable plastics used as an ecofriendly alternative for conventional plastics in various applications. In this study, an industrial-scale PHA production system was designed and analyzed for the material flows and economics with the use of SuperPro Designer. Haloferax mediterranei was utilized to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Byproduct streams from a local cheese plant, with an input of 168.7 metric ton/day (MT/day) lactose, were used as the feedstock. Three scenarios with different processes for the treatments of used enzyme and spent medium were investigated and the major factors that influence the overall economics were identified. The simulated system produces 9700 MT/year PHBV with a yield of 0.2 g PHBV/g lactose and an overall process efficiency of 87%. The breakeven price was found to be more sensitive to the lactose price than enzyme price. The scenario with enzyme reuse and spent medium recycling a... [more]

This paper takes the position control performance of pump-controlled hydraulic presses as the research object. The control methods are designed respectively for the two motion stages of rapid descent and slow descent of hydraulic presses in order to improve the control performance of the system. First of all, the accuracy model of the pump-controlled hydraulic presses position servo system (the pump-controlled hydraulic presses position servo system, which is called PCHPS) and its MATLAB/Simulink simulation platform are established. Based on the theoretical analysis and experimental data, the interference factors affecting the tracking accuracy and positioning accuracy of the PCHPS are analyzed. Then, an adaptive integral robust control (the adaptive integral robust control, which is called AIRC) for PCHPS is designed to reduce the influence of nonlinear factors on the system, and the effectiveness of the controller is verified by simulation. Finally, the position control experiment of... [more]

The paper presents a case study describing the process of creating and validating the benefits of two Innovative Learning Tools (ILTs) aimed at more effective knowledge acquisition in the interdisciplinary field of earth resource extraction with links to the status of renewable energy. The philosophy behind the original designs and the design of the two tools, the way they are used, and the results of their application in the educational process are presented in a framework. The opinions and attitudes of both students and educators towards the tools were surveyed, and some research questions related to this form of knowledge acquisition were validated. The presented results show the students’ interest in the educational form as well as the attractive content that goes beyond conventional educational subjects, with its connections.

This study was conducted at the ethanol plant of Metehara sugar factory, at a laboratory scale, to assess the effect of recycling vinasse into the fermentation process on effluent reduction. Vinasse is an effluent produced from distilleries. The experimental design included vinasse concentrations at 4 dilution rates (0 (control), 20, 35, 50, and 65% of process water) with 2 replicates and 6 responses, as follows: ethanol yield, fermentation efficiency, residual sugar concentration, cell count, cell viability, and calcium oxide content. In this study, the actual operational parameters of the ethanol plant were maintained during the experiment. The result of the experiment indicates that, with up to 20% vinasse recycling, there was no influential impact on the ethanol yield, the fermentation efficiency, the residual sugar concentration, or the calcium oxide content, attributable to the recycling, as compared to the control. Above 20% vinasse recycling, ethanol yield and fermentation effi... [more]

The double-layer blanket (DLB) reverse offset is a newly designed printing process for patterning electronic circuits on a 3D curved surface. Unlike the existing reverse offset process, the DLB reverse offset utilizes an offset roll composed of two layers comprising polydimethylsiloxane (PDMS) and a thick, soft cushioned rubber to print microelectrode patterns and transparent electrodes on a curved surface. The optimal printing process was determined by adjusting the printing pressure and printing speed for horizontal and vertical micropatterns, based on which transparent electrodes with metal mesh and honeycomb structures with a line width of 30 μm and pitch of 600 μm with micropatterns ranging from 30 μm to 60 μm were printed on a curved surface. Ag ink was used, and the 3D curved surface indicated a print quality similar to that of the flat surface for both the vertical and horizontal patterns and transparent electrodes. The DLB reverse offset technique demonstrated the possibility... [more]

Despite great efforts to develop a vaccine against human immunodeficiency virus (HIV), which causes AIDS if untreated, no approved HIV vaccine is available to date. A promising class of vaccines are virus-like particles (VLPs), which were shown to be very effective for the prevention of other diseases. In this study, production of HI-VLPs using different 293F cell lines, followed by a three-step purification of HI-VLPs, was conducted. The quality-by-design-based process development was supported by process analytical technology (PAT). The HI-VLP concentration increased 12.5-fold while >80% purity was achieved. This article reports on the first general process development and optimization up to purification. Further research will focus on process development for polishing and formulation up to lyophilization. In addition, process analytical technology and process modeling for process automation and optimization by digital twins in the context of quality-by-design framework will be devel... [more]

The impressive developments in commercially available technologies, in terms of new equipment and faster computers, allow us to solve ever-more complicated chemical and technical issues within industrial chemistry and reaction engineering fields [...]

This paper proposes a concept of a process design for the separation and recovery of n-butanol from a five-component mixture, consisting of n-butanol, isobutanol, formaldehyde, water and methanol. The mixture is a common waste stream in the production of butylated amino resins; therefore, recovery of n-butanol is crucial to the efficiency of the process. The results show that up to 94% of the n-butanol present in the waste stream can be recovered. Under the studied conditions, 99.76% pure n-butanol can be obtained, while formaldehyde, water and methanol are present only in traces. The energy intensity of the process is estimated at 2.42 MJ/kg of purified n-butanol. The economic analysis of the process shows that the process is economically viable over a wide range of production capacities, as evidenced by high net present values and high return on investment values.

During long-term continuous braking, high-intensity braking, or frequent braking, the temperature of the brake disc or brake drum will increase significantly, resulting in a decrease in the friction coefficient, the aggravation of the wear degree, and the dangerous heat recession of partial or even total loss of braking efficiency. This paper focuses on an innovative double rotor permanent magnet braking device, which is located on the inner side of the wheel hub, to improve the heat decay resistance of the friction braking device. The structure and principle of the double rotor permanent magnet braking device were given, and its main structural parameters were designed, calculated, and optimized. The geometric model and finite element model of the double rotor permanent magnet braking device were established. The static and transient magnetic field analysis and the braking torque characteristic analysis of the double rotor permanent magnet braking device were carried out by using Maxw... [more]

ADAMTS13 is a hemostatic enzyme that breaks down pro-thrombotic ultra-large multimers of von Willebrand factor (VWF). The deficiency of ADAMTS13 increases VWF-mediated thrombogenic potential and may lead to thrombotic thrombocytopenic purpura (TTP). Recently, clinical studies have shown the development of acquired TTP after COVID-19 infection and a correlation between low ADAMTS13 plasma levels and increased mortality. As a result, investigating ADAMTS13 as a potential recombinant therapeutic is of broad interest in the field of hematology. ADAMTS13 is considered challenging to purify in its biologically active state. Current purification methods utilize immobilized metal ions, which can interfere with ADAMTS13 metalloprotease activity. For this reason, we optimized an alternative strategy to isolate milligram quantities of highly active recombinant ADAMTS13 (rADAMTS13) from conditioned media after exogenous expression in human cell line, HEK293. HEK293 cells stably expressing C-termin... [more]

Design decisions occur in all phases of product design and largely affect the merits of the final solution, which will ultimately determine the success or failure of the product in the market. Product design is a continuous process, and a large number of existing studies have proposed decision methods and decision indicators for the characteristics of different stages of design. These methods and indicators can meet the requirements of one of the phases: demand analysis, conceptual design, or detailed design. However, further research can still be conducted on the integration of methods throughout the design phase, using intelligent design methods, and improving the design continuity and efficiency. To address this problem, a TOPSIS-MOGA-based multi-indicators decision model for product design solutions is proposed, including its product design process, decision algorithm, and selection method. First, a TOPSIS-MOGA integrated model for conceptual design and detailed design process is e... [more]

Biological products are increasingly important, and therefore the industry has begun to adopt quality by design, as recommended by the ICH and the U.S. FDA. Smaller companies, however, have faced difficulties in employing full-scale experiments or the quality by design strategy. Thus, this study provides an alternative way to build a model from existing data with experimental software that does not require full-scale experiments. This empirical study hopes to provide a practical way to improve the efficiency of smaller biopharmaceutical companies and researchers. Moreover, the models provided here can be applied to process characterization in recombinant protein production.

The two-fluid model (TFM) coupled with the kinetic theory of granular flow (KTGF) has gradually been used for modeling dense granular flows and mixing in rotating drums in recent years. In the present paper, a review is made from the perspective of model development and model application. It is found that several frictional viscosity models were proposed to consider the enduring contact of dense particles for the specific rotating studied, but there is still a lack of a universal model. The model is validated by various experiment results and the applicability is indicated. The model is used for investigating dynamic particle flow, and the effects of the parameters on granular flow behavior and flight design. Although the model theoretically has the advantage of saving computing resources, and is suitable for industrial-scale modeling, it is found that the model is used for the research of laboratory-scale rotating drums (diameter less than 0.5 m) and has not been used for industrial r... [more]

Fracture network fracturing combined with oil−water infiltration and replacement is an effective approach to develop tight sandstone reservoirs. How to further improve oil recovery based on imbibition is a problem encountered during production. In this study, the core of the CHANG-7 tight sandstone reservoir in the Changqing oilfield of the China National Petroleum Corporation (CNPC) is studied. Combined with the newly designed core self-imbibition experiment, the mechanisms of salinity action are studied, and the influence of salinity on the process of imbibition oil recovery is quantitatively characterized. Research results show that the influence of salinity on the imbibition process of tight sandstone reservoirs takes place mainly through two ways; one is to reduce the oil−water interfacial tension, and the other is to construct an osmotic pressure displacement model. The salinity has significant influences on interfacial tension. The interfacial tension of low-salinity brine is on... [more]

In this study, we aimed to select the optimal solvents for the removal of asphaltene−resin−paraffin deposits. The effectiveness of various solvents was determined based on the asphaltene−resin−paraffin deposits (ARPDs) of the Zhanaozen (Ozen) crude oil field. These deposits affect the geological, physical, and technological conditions of the oil field, thus influencing its development. According to the results, we found that the most effective composite solvent is a composition comprising a 50% gasoline fraction and a 50% kerosene fraction. This composition showed mass loss of deposits of 97.7% and a dissolving power of 93.5 g/cm3 after 5 h. We confirmed the effectiveness of this composition by the paraffinic type of the deposits, which is explained by the high content of paraffin in the oil from the Zhanaozen field. Aromatic solvents showed a relatively low dissolving power compared with aliphatic solvents, which also confirms the low content of resins and asphaltenes in the ARPD.

This paper studies the flow characteristics and disk friction loss of the rear chamber in a centrifugal pump at a design flow condition with six values of the balance holes at diameters from 0 to 12 mm. The results show that the turbulent boundary layer in the rear chamber is greatly affected by the leakage flow. When the balance hole diameter increases, the flow characteristics of the rear chamber is mainly restricted by the mainstream flow field of the volute. However, when the balance hole diameter is larger than the design value, the disk friction loss of the rear chamber remains basically unchanged. On the contrary, when the balance hole diameter is smaller than the design value, the larger the balance hole diameter the smaller the friction loss of the disk in the rear chamber area. The results of this paper provide a reference for reducing axial force and stable operation of a centrifugal pump.

Nitrate ion (NO3−) in wastewater is a major cause of pollution in aquatic environments worldwide. Magnetospirillum gryphiswaldense (MSR-1) has a complete dissimilatory denitrification pathway, converts NO3− in water into nitrogen (N2) and simultaneously removes ammonium ions (NH4+). We investigated and confirmed direct effects of regulatory protein factors Mg2046 and MgFnr on MSR-1 denitrification pathway by EMSAs and ChIP-qPCR assays. Corresponding mutant strains were constructed. Denitrification efficiency in synthetic wastewater medium during a 12-h cell growth period was significantly higher for mutant strain Δmgfnr (0.456 mmol·L−1·h−1) than for wild-type (0.362 mmol·L−1·h−1). Presence of magnetic particles (magnetosomes) in MSR-1 greatly facilitates collection and isolation of bacterial cells (and activated sludge) by addition of a magnetic field. The easy separation of magnetotactic bacteria, such as MSR-1 and Δmgfnr, from wastewater using magnetic fields is a unique feature that... [more]