As an alternative to conventional anaerobic digestion for methane production, anaerobic fermentation (AF) of organic matter can produce short chain organic acids (SCOAs) in a sustainable way. This study investigated the effect of microwave (MW) pre-treatment on the AF of model food waste to SCOAs and ethanol. The MW pre-treatment was investigated at three temperatures (120, 150 and 180 °C) and residence times (2, 5 and 8 min). The MW treatment gave a significant reduction in the pH and volatile suspended solids (VSS). The largest reduction in the VSS was 20%, indicating solubilisation of the organic matter. The latter was also confirmed by the increase, although it was not statistically significant, in the soluble chemical oxygen demand (COD) and soluble carbohydrates. In the fermentation batch tests, the total product yield was higher (17.5% COD COD−1) than for the untreated substrate (11.1% COD COD−1). An electricity price of GBP 0.06 kWh−1 would correspond to the market value of the... [more]

The existing mechanical wear detection methods cannot accurately obtain the state characteristic data of mechanical equipment, resulting in high detection accuracy but low detection efficiency. In order to obtain more ideal results of mechanical wear detection, the mechanical wear detection technology of a high-power diesel engine based on thermodynamic coupling is designed. Through the coupling of thermodynamics, the thermal stress in the body is solved under the temperature field and corresponding boundary conditions. The state data of mechanical equipment are collected, the wavelet entropy in the state data of mechanical equipment is extracted as the feature of mechanical wear detection, and the least squares support vector machine is used to establish the mechanical wear detection model. The multi-domain unified language modelica is used to model the thermodynamic module and dynamic module of the diesel engine, respectively, to realize the joint simulation of thermodynamics and dyn... [more]

Actinomycetes are natural architects of numerous secondary metabolites including antibiotics. With increased multidrug-resistant (MDR) pathogens, antibiotics that can combat such pathogens are urgently required to improve the health care system globally. The characterization of actinomycetes available in Nepal is still very much untouched which is the reason why this paper showcases the characterization of actinomycetes from Nepal based on their morphology, 16S rRNA gene sequencing, and metabolic profiling. Additionally, antimicrobial assays and liquid chromatography-high resolution mass spectrometry (LC-HRMS) of ethyl acetate extracts were performed. In this study, we employed a computational-based dereplication strategy for annotating molecules which is also time-efficient. Molecular annotation was performed through the GNPS server, the SIRIUS platform, and the available databases to predict the secondary metabolites. The sequencing of the 16S rRNA gene revealed that the isolates BN6... [more]

The good manufacturing practices (GMP) and process analytical technology (PAT) initiatives of the US Food and Drug Administration, in conjunction with International Council for Harmonisation (ICH) quality guidelines Q8, Q9, and Q10, ensure that manufacturing processes for parenteral formulations meet the requirements of increasingly strict regulations. This involves the selection of suitable process analytics for process integration and aseptic processing. In this article, we discuss the PAT requirements for the GMP-compliant manufacturing of parenteral lipid emulsions, which can be used for clinical nutrition or for the delivery of lipophilic active ingredients. There are risks associated with the manufacturing processes, including the potential for unstable emulsions and the formation of large droplets that can induce embolisms in the patient. Parenteral emulsions are currently monitored offline using a statistical approach. Inline analytics, supplemented by measurements of zeta pote... [more]

Robots are being increasingly utilized for various operations in industrial and household applications. One such application is for spray painting, wherein atomized paint particles are sprayed on a surface to coat the surface with paint. As there are different models of robots available for the job, it becomes crucial to select the best among them. Multi-criteria decision-making (MCDM) techniques are widely used in various fields to tackle selection problems where there are many conflicting criteria and several alternatives. This work focuses on selecting the best robot among twelve alternatives based on seven criteria, among which payload, speed, and reach are beneficial criteria while mechanical weight, repeatability, cost, and power consumption are cost criteria. Five MCDM techniques, namely combination distance-based assessment (CODAS), complex proportional assessment (COPRAS), combined compromise solution (CoCoSo), multi-attributive border approximation area comparison (MABAC), an... [more]

Multi-equipment multi-process frequent scheduling under complex constraints is at the root of a large number of idle time fragments and transport waiting time in multi-equipment processes. To improve equipment utilization and reduce idle transportation time, a production process optimization scheduling algorithm with “minimum processing time and minimum transportation time” is proposed. Taking into account factors such as product priority, equipment priority, process priority, and overall task adjustment, the scheduling optimization is carried out through a hybrid algorithm combining a one-dimensional search algorithm and a dual NSGA-II algorithm. Compared with other algorithms, the scheduling algorithm proposed in this article not only shortens the minimum processing time but also strives to maximize the utilization rate of each piece of equipment, reducing the processing time of the enterprise by 8% or more, while also reducing the overall transportation time and indirectly reducing... [more]

Currently, nanotechnology is considered a promising strategy to enhance drug solubility and other physicochemical properties. Albumin is a biopolymer that can be used in drug delivery systems due to its biodegradability and biocompatibility. The aim of this study was to prepare and characterize albumin nanoparticles with chlorambucil as a controlled drug delivery system. Different concentrations of chlorambucil were incubated with bovine serum albumin (BSA) in order to prepare nanoparticles using the desolvation method. As a result, nanoparticles in sizes ranging from 199.6 to 382.6 nm exhibiting high encapsulation efficiency of chlorambucil were obtained. A spectroscopic study revealed concentration-dependent changes in secondary structure of the albumin chain and in the hydrophobicity of chlorambucil. Based on the results obtained, it was concluded that the investigated structures may be used in the development of a drug delivery system.

Vibration signals from centrifugal pumps are nonlinear, non-smooth, and possess implied trend terms, which makes it difficult for traditional signal processing methods to accurately extract their fault characteristics and details. With a view to rectifying this, we introduced empirical mode decomposition (EMD) to extract the trend term signals. These were then refit using the least squares (LS) method. The result (EMD-LS) was then combined with multi-fractal theory to form a new signal identification method (EMD-LS-MFDFA), whose accuracy was verified with a binomial multi-fractal sequence (BMS). Then, based on the centrifugal pump test platform, the vibration signals of shell failures under different degrees of cavitation and separate states of loosened foot bolts were collected. The signals’ multi-fractal spectra parameters were analyzed using the EMD-LS-MFDFA method, from which five spectral parameters (Δα, Δf, α0, αmax, and αmin) were extracted for comparison and analysis. The resul... [more]

This paper studies hydraulic cylinder position adjustment controlled by an on−off valve. The aim of this paper is to develop a method of position control for a hydraulic cylinder based on input and output pressure under the mutual coupling feedback of the load and flow, especially in multi-actuator coupling control scenarios. This method can solve the problem of position evaluation and hydraulic cylinder tracking in relation to position detection without a displacement sensor and provide the possibility of automatic adjustment of hydraulic support in the process of intelligent mining. First of all, according to the flow continuity equation and Navier−Stokes equation, a flow model with inlet and outlet pressure is derived. Secondly, the effectiveness of the flow resistance characteristic curve of differential valve is verified by experimental and theoretical analysis. Finally, through experimental verification, when the system pressure is larger than 10 MPa, the error between the actual... [more]

This paper presents a low-cost, high-temperature-resistant and high-strength polyacrylamide gel system formed by secondary cross-linking. The gel system (named JM186) used phenolic resin and organic zirconium as cross-linking agents, and the performance of the gel system was systematically evaluated under high temperature. The gel properties studied include: gel formation time, gel strength, thermal stability, sand-filled pipe sealing efficiency, and its microstructure. The concentration of polyacrylamide in JM186 gel system was as low as 0.3%, which can control the gelling time in a range of 1−9 h by adjusting the ratio of two cross-linking agents. It can resist temperature up to 120 °C without dehydration, and its highest gel strength can reach H grade. The modulus of elasticity (G’) and viscosity (G”) can reach 32.33 Pa and 3.25 Pa, respectively. DSC (differential scanning calorimetry) test indicated that the temperature of structural failure for this composite gel is 310.5 °C. The... [more]

Ready-made Chinese herbal medicine (RMCHM) is one of the most common types of synergistic herbal medicine used worldwide. It is based on composite herbal formulae (CHF), which makes quality control of this kind of traditional Chinese medicine (TCM) difficult, let alone distinguishing the good from the bad. Taking Niuhuang Qingwei Pills (NHQWP) as an example, this study reported the development of a novel principle of analysis of multiple components in RMCHM. Experimental procedures involved the selection of high-quality Chinese materia medica (CMM, individual medicinal plant parts used in the NHQWP) to prepare three batches of TCM reference drugs (TCMRD). Pure compounds of the active ingredients identified in the herbal formula including berberine hydrochloride, geniposide, forsythiaside A, 3,5-O-dicaffeoyl quinic acid, hesperidin, baicalin, glycyrrhizic acid, and chrysophanol in the three TCMRDs were analyzed as well as those in 49 batches of commercial products from 18 manufacturers... [more]

This study uses a self-developed anti-corrosion pill particle as the research object and develops the pill particle population modelling method in order to optimize the anti-corrosion process of oil and gas wellbore casing annuli. The shape of the pill particle is similar to a cylinder, according to the test and analysis of geometrical characteristics, and can be simplified into three types based on height, namely pill particles A (5.4 mm), B (5.8 mm), and C (6.2 mm). The multi-sphere approach is then used to create models of three different types of pill particles with varying degrees of precision. The feasibility and effectiveness of the modelling method for pill particle populations are proven by comparing the simulation results of the bulk density test and the angle of repose test. The results show that the 12-sphere models of pill particles A, B, and C are accurate representations of genuine pill particle morphologies and are adequate for simulating particle mechanics and flow pro... [more]

The pharmaceutical industry has been quite successful in developing new hydrogenation processes, and the chemistry of hydrogenation is currently well understood. However, it is a complex process to scale and optimize due to its high exothermicity, use of expensive catalysts and solvents, and its mass transfer requirements. Therefore, the aim of this work is to develop a CFD model to be able to describe the mass transfer, hydrodynamics, and mixing with respect to changes in rotational speed for a full-scale pharmaceutical hydrogenation reactor. In the first stage, a simple CFD model is used to predict the development of the surface vortex, and it is validated against literature data. In the second stage, the CFD model is tested on a full-scale configuration equipped with a Rushton turbine and a bottom kicker to study the formation of the surface vortex. Simulation results show the ability to predict the development of the surface vortex. These results are used to estimate the liquid hei... [more]

In the train operation department, humans are the most important and dynamic element, and their safe behavior is directly related to the safety of railway transportation. How to accurately assess the safety behavior risk of on-site workers is an urgent problem to be solved. In risk practice, some scholars directly use the accident potential data to calculate the risk parameters, and the accuracy of the risk magnitude is greatly affected by the data quality. Second, the traditional two-dimensional matrix only considers two external factors, probability and severity, without an in-depth analysis of the inherent vulnerability of risk, resulting in low accuracy of risk assessment. With a focus on the hazard factor, this study proposes a three-dimensional risk assessment approach based on grid management to carry out a personalized risk assessment of grid events. Through the grid division, the method can accurately identify the risk events of employees in any cell grid at a certain moment i... [more]

This paper focuses on the frequency domain fluid−structure interaction (FSI) vibration characteristics of aircraft hydraulic pipe with complex constraints. The linear partial differential fourteen-equation model is applied to describe the nonlinear FSI dynamics of pipes conveying fluid with high-speed, high-pressure, a wide Reynolds number, and the vibration frequency range. The excitation, complex boundary, and middle constraint models of liquid-filled pipes are analytically established and added into the global model of the pipe system. These resulting models are solved by the improved Laplace transform transfer matrix method (LTTMM) in the frequency domain. Then, the dynamic response characteristics of an aircraft hydraulic pipe containing diverse constraints are investigated numerically and experimentally under four types of working conditions, and the improvement conditions for the numerical instabilities are presented. In general, the present method is highly efficient and conven... [more]

A dynamically operated sorption-enhanced water−gas shift reactor is modelled to leverage its performance by means of model-based process design. This reactor shall provide CO2-free synthesis gas for e-fuel production from pure CO. The nonlinear model equations describing simultaneous adsorption and reaction are solved with three numerical approaches in MATLAB: a built-in solver for partial differential equations, a semi-discretization method in combination with an ordinary differential equation solver, and an advanced graphic implementation of the latter method in Simulink. The novel implementation in Simulink offers various advantages for dynamic simulations and is expanded to a process model with six reaction chambers. The continuous conditions in the reaction chambers and the discrete states of the valves, which enable switching between reactive adsorption and regeneration, lead to a hybrid system. Controlling the discrete states in a finite-state machine in Stateflow enables automa... [more]

Among multilevel inverters (MLIs), two-level inverters are the most common. However, this inverter type cannot maintain total harmonic distortion (THD) due to its limited number of levels. Reductions in THD are inversely proportional to the number of levels where increased output occurs in diverse ways, and the use of fewer components with low harmonic distortion is necessary for such reductions. This work proposes a seven-level (7L) MLI design with a small number of components and low harmonic distortion. The proposed MLI is combined with switched capacitor (SC) cells to promote output levels and at the same time to boost the input voltage. The connections between the capacitor and the source are based on the series to parallel topology, where the charging and discharging of the SC cells are caused by fluctuations in their connection. The output of the SC cell is combined with an H-bridge inverter controlled by a proposed PWM controller. The simulation result of the SC 7L inverter was... [more]

Manufacturing processes need optimization. Three-dimensional (3D) printing is not an exception. Consequently, 3D printing process parameters must be accurately calibrated to fabricate objects with desired properties irrespective of their field of application. One of the desired properties of a 3D printed object is its tensile strength. Without predictive models, optimizing the 3D printing process for achieving the desired tensile strength can be a tedious and expensive exercise. This study compares the effectiveness of the following five predictive models (i.e., machine learning algorithms) used to estimate the tensile strength of 3D printed objects: (1) linear regression, (2) random forest regression, (3) AdaBoost regression, (4) gradient boosting regression, and (5) XGBoost regression. First, all the machine learning models are tuned for optimal hyperparameters, which control the learning process of the algorithms. Then, the results from each machine learning model are compared using... [more]

A new supervisory training rule for a shallow fully connected neural network (SFCNN) is proposed in this present study. The proposed training rule is developed based on local linearization and analytical optimal solutions for linearized SFCNN. The cause of nonlinearity in neural network training is analyzed, and it is removed by local linearization. The optimal solution for the linearized SFCNN, which minimizes the cost function for the training, is analytically derived. Additionally, the training efficiency and model accuracy of the trained SFCNN are improved by keeping estimates within a valid range of the linearization. The superiority of the proposed approach is demonstrated by applying the proposed training rule to the modeling of a typical nonlinear pH process, Boston housing prices dataset, and automobile mileage per gallon dataset. The proposed training rule shows the smallest modeling error and the smallest iteration number required for convergence compared with several previo... [more]

Urban water systems are still in their infancy regarding the transition toward a circular economy, despite the sporadic successful examples worldwide. This paper was aimed at analyzing the preparedness of four water utilities in Bulgaria for the implementation of circular economy principles and solutions. These utilities provide water supply and sewerage services to about 30% of the population in Bulgaria. SWOT analysis was used as a core tool. Publicly available data such as nonrevenue water, pressure management, energy demand, network digitalization, and sludge utilization were used to explore the internal factors. The external environment was considered through the legislative and socioeconomic framework, climate change, etc. Finally, the credibility of the conclusions was verified in workshops with the water utilities. The key positive outcomes were that the external factors favor the shift to circular systems, while the major weakness, i.e., the aged infrastructure, is actually a... [more]

Even though Industry 4.0 is primarily focused on the implementation of advanced digital technologies, this is not the only aspect that should be considered. One of the aspects that calls for attention is the ability to create a sustainable and agile industrial environment. In this sense, the role of project management is crucial for achieving business excellence in a new industrial paradigm. The main goal of this paper was to determine the impact of different levels of project management maturity on business excellence in the context of Industry 4.0. The research in the paper was made using a sample of 124 organizations, differing in industry type and size, and recognized through the business excellence awards or recognitions given by European Foundation for Quality Management (EFQM). Using the Project Management Maturity Model (ProMMM), a significant connection was found between project management maturity and business excellence. Considering technology advances, these relationships w... [more]

In underground coal gasification (UCG), it is essential for UCG production to accurately control the temperature of the gas produced at the wellhead of the production well and correctly calculate the variation law of the temperature field in the whole wellbore. UCG wellbore structures use three wellbore sprayed water cooling schemes. These schemes consider the heat exchange mechanism between the wellbore and the formation, the division of the production wellbore into the spray chamber section and the non-spray section, and the established temperature field model of the whole wellbore. The research shows that, due to the large temperature gradient formed in the wellbore heat transfer route under the spray tubing water injection cooling scheme, the temperature of the produced gas drops the most. The annular water injection cooling scheme can protect the cement sheath to a certain extent and is easier to implement; therefore, it is more suitable to use this scheme to cool the production w... [more]

Biosorption has great potential in removing toxic effluents from wastewater, especially heavy metal ions such as cobalt, lead, copper, mercury, cadmium, nickel and other ions. Mathematically modeling of biosorption process is essential for the economical and robust design of equipment employing the bioadsorption process. However, biosorption is a complex physicochemical process involving various transport and equilibrium processes, such as absorption, adsorption, ion exchange and surface and interfacial phenomena. The biosorption process becomes even more complex in cases of multicomponent systems and needs an extensive parametric analysis to develop a mathematical model in order to quantify metal ion recovery and the performance of the process. The biosorption process involves various process parameters, such as concentration, contact time, pH, charge, porosity, pore size, available sites, velocity and coefficients, related to activity, diffusion and dispersion. In this review paper,... [more]

The influence of the multi-stage electrostatic separation (ESS) of mechanically treated and magnetically separated waste electronic material and the pyrolysis of the selected ESS fraction on the distribution of metal elements (MEs), elements contained in refractory oxides (EROs), bromine (Br), and rare-earth elements (REEs) contained in waste electronic material was studied. The concentration of MEs, Br, and EROs in the tested samples was determined by X-ray fluorescence analysis, and the concentration of REEs and uranium was determined by inductively coupled plasma mass spectrometry (ICP-MS). The analysis of the distribution of elements during the multi-stage ESS showed that MEs were predominantly distributed in the conductive fraction and Br, EROs, and REEs were distributed in the nonconductive fraction. The nonconductive fraction (NC2) of the two-stage ESS was subjected to a low-temperature vacuum pyrolysis (T = 550 °C, p = 10 mbar). The distribution of pyrolysis products of the NC2... [more]

Global society has experienced a tremendous development since the institution of civilization [...]