Xylose is nowadays converted into xylitol, a popular special chemical sweetener. Xylitol can be used not only in the pharmaceutical and food industries, but also in cosmetics and synthetic resins because of its countless properties. Conventionally, xylitol is produced by slurry reactors operating in batch with dispersed or supported catalysts. Hydrogen is continuously fed to maintain a constant pressure. In this work, the kinetics of the reaction were investigated to find the optimal operating conditions to minimize the by-products obtained. Given the great performances shown by the new Ru/SiO2 sol−gel derived catalyst in glucose hydrogenation, in this work the mentioned catalyst was tested in the hydrogenation of xylose to xylitol both in batch and in continuous production to prove its stability and activity.

Operating time series data collected and stored in historian must be managed to extract their full potential. Part 1 of this paper proposed a structured way (a sophisticated approach) to process industrial data; this first part explains in detail the data processing framework used as the basis for the costing analysis present in the second part of this series. The framework considers the analysis scope definition, data management steps, and operating regimes detection and identification. The added value of this proposed framework is demonstrated in Part 2 via the use of cost accounting for operational problem-solving (debottlenecking), i.e., its practicality is validated via its application alongside a cost analysis on the brownstock washing department of a kraft pulp mill. The traditional debottlenecking approach assumes a single operating condition considering that operating regimes allow for a much more sophisticated debottlenecking study of the washing department. With the use of o... [more]

In this paper, a closed hydrostatic drive powertrain (HSDP) composed of an engine, a variable pump, a variable motor, and an energy-efficient adaptive speed-regulating controller (ADC) based on power following is proposed and investigated. The controller can more than guarantee accurate regulation of motor speed through online efficiency estimation based on established loss models of the pump and the motor. It also facilitates the optimal efficiency control of the engine and hydrostatic system through two redundant control freedoms of the HSDP system, making an energy-saving adjustment of the motor speed. At the same time, the controller can prevent engine overload stall and high system pressure by limiting the displacement of the pumps and motors in real time based on the system loads to improve the automatic adaptability of the system to varying loads. Field testing experiments performed by means of a heavy transportation vehicle under different conditions were conducted to verify th... [more]

Betulin is a birch bark-derived lupane-type pentacyclic triterpene with a wide spectrum of biological activities. Given their enhanced antiproliferative potential and enhanced pharmacological profile, betulin derivatives are continuously investigated in scientific studies. The objective of the current study was to in vitro assess the antiproliferative properties of novel synthesized 1,2,4-triazole derivatives of diacetyl betulin. The compounds were investigated using three cancer cell lines: A375 (melanoma), MCF-7 (breast cancer), HT-29 (colorectal cancer), and HaCaT (human keratinocytes). Bet-TZ1 had the lowest recorded IC50 values (ranging from 22.41 to 46.92 μM after 48 h of exposure) than its precursor and other tested compounds in every scenario, with the highest cytotoxicity against the A375 cell line. Bet-TZ3 demonstrated comparable cytotoxicity to the previously mentioned compound, with an IC50 of 34.34 μM against A375. Both compounds caused apoptosis in tested cells, by induci... [more]

In this study, 2% chitosan (Ch) (w/v) was enriched with 1% Lippia javanica, Syzygium cordatum, and Ximenia caffra extract to form Ch+L, Ch+S, and Ch+X, respectively. The control film was the chitosan (Ch) film without plant extracts. The composite films were assessed for their antifungal ability using the agar diffusion method against economically relevant plant pathogens, Botrytis cinerea, and Penicillium expansum. These chitosan films were further evaluated using an X-ray diffractometer and scanning electron microscope, and their physical and mechanical properties were also assessed. The medicinal plants in the chitosan matrix had the highest inhibition zone (10 mm) against P. expansum, while the chitosan-only films had the lowest inhibition zone (3.3 mm). Notably, Ch+S and Ch+X films had the highest inhibition zone (10 mm) against B. cinerea, while chitosan-only films did not avert the spread of B. cinerea. Ch+L films had the highest film thickness (0.189 mm), density (1.62 g·cm3),... [more]

This study presents an aerostructural optimization process for wind turbine blades aimed at enhancing the turbine’s performance. The optimization framework integrates DAFoam as the computational fluid dynamics (CFD) solver, TACS as the finite element method (FEM) solver, Mphys for fluid−structure coupling, and SNOPT as the optimizer within the OpenMDAO framework. The objective is to simultaneously increase the torque generated by the wind turbine while decreasing the mass of the blade, thereby improving its efficiency. The design variables in this optimization process are the blade shape and panel thickness. The aerodynamic objective function is torque, a key performance indicator for wind turbine efficiency. The structural objective function is the blade mass, as reducing mass is essential to minimize material and manufacturing costs. The optimization process utilizes the integrated capabilities of DAFoam, TACS, Mphys, and SNOPT to iteratively evaluate and modify the blade shape and p... [more]

This study covers the critical concerns related to the sizing, selection, installation, maintenance, and testing of pressure safety valves (PSVs). The aim is to ensure the safety of pressurized systems, hydrostatic transmission systems, and hydraulic plants, including process plants, thermal power plants, and nuclear reactor systems. PSVs are devices that ensure the safety and reliability of pressurized vessels, lines, and systems during overpressure events. The task of selecting which PSV features are of greatest value for a specific purpose is complex—especially in the design of a high-pressure experimental thermal−hydraulic facility for hydrostatic and transient testing of the reactor system—when the systems are in the design and development phases and require qualification and demonstration to prove that they have reached a given level of technological readiness. The present study highlights the required steps for users to follow the associated rules, guidelines, and recommendation... [more]

Coal is complex as it includes organic matter (macerals) and inorganic matter (minerals) [...]

This paper addresses the pressing need for advanced simulation tools in electric phasor modeling and Smart Grid-Power to X systems. The motivation for this study stems from the critical importance of enhancing the balance between performance and the detailed dynamic representation of the system behavior in the simulations. The identified problem lies in the absence of a comprehensive framework that seamlessly integrates electric phasor DQ0 components into a multi-purpose object-oriented environment. The primary objective of this research is to develop and introduce two simulation libraries, centered around the core component, Electric_DQ0. These libraries aim to establish a robust phasor-based framework, incorporating essential electric components such as sources, loads, branches, power converters, and electric machines. The main goal is to enable dynamic frequency and voltage simulations, particularly focusing on transients in alternators and facilitating Voltage and Frequency Rate of... [more]

This paper presents a detailed analysis of the relation between physical characteristics and defects of green coffee beans and the sensory profile that influence the sensory notes of fragrance, aroma, flavor, and aftertaste of coffee. Machine learning models were used to identify the variables of importance and identify the ways in which these variables affect the sensory note of coffee, to determine which algorithm and its hyperparameters have greater precision in determining the sensory values of coffee such as floral, fruity, herbal, nutty, caramel, chocolate, spicy, resinous, pyrolytic, earthy, fermented, and phenolic. The result indicates the relationship and importance that exist between the physical variables, defects, and size of the green coffee bean, with respect to their respective sensory notes. The data of the proposed system demonstrate that by combining the scores of several experts, a precision can be achieved analogously to that obtained by cupping experts; therefore,... [more]

Remanufacturing processes are one of the key pillars of the so-called closed-cycle economy. Unfortunately, the design and organization of such processes pose a significant problem, due to, among other things, the high variability of the process as a consequence of both the degree of wear and tear and the quality of the remanufactured components. This article presents a method for optimizing the flow of the brake caliper remanufacturing process in the MTO (make-to-order) model. For the optimization process, the system dynamics (SD) method, which belongs to a group of simulation methods, was used. The developed model allows, in particular, the prediction of the number of components at the input to the regeneration process and the method of defining the size of the transport batch and evaluating its impact on the length of the production cycle of the batch of regenerated products. The issues of staffing management at individual positions and the organization of transport operations with v... [more]

The real-time and accurate recognition of fruits and vegetables is crucial for the intelligent control of fruit and vegetable robots. In this research, apple picking is selected. This study proposed a lightweight, coupon-product, neural-net terminal YOLO algorithm for apple image recognition. Compared with the YOLO series algorithm, the tiny algorithm shows a strong relationship with the calculation speed. In traditional red fruit detection, the recognition time is generally several seconds, which is unacceptable in the real-time system. In this research, a total of 2000 apple images from different environments are used as a dataset for training and testing. The YOLOv4-tiny model is detailed, instructed, and used for the identification. The indicators, such as F1Score (0.92) and mAP (95.5% average), are analyzed by calculating the loss rate, accuracy rate (96.21%), and recall rate (95.47%). Finally, the algorithm shows good accuracy and high speed (no more than 5 ms) in online real-tim... [more]

Distillation is significantly influenced by energy costs, prompting a need to explore effective strategies for reducing energy consumption. Among these, heat integration is a key approach, but evaluating its efficiency is paramount. Therefore, this study presents exergy as an energy quality indicator, analyzing irreversibility and efficiencies in tetrahydrofuran/water and acetone/chloroform distillations. Both systems have equimolar feed streams, yielding products with 99.99 mol% purity. The simulations are performed using Aspen Plus™, enabling evaluation at the column level, as a standalone process, or from a lean perspective that considers integration opportunities with other plants. The results show that, despite anticipated energy savings from heat integration, economic viability depends on pressure sensitivity. The results demonstrate that heat-integrated extractive distillation for acetone/chloroform raises utility energy consumption. Exergy calculations comparing standalone and... [more]

Although the importance of black copper ores is well established, many topics remain to be studied. This manuscript describes the efforts to improve copper recovery from refractory ores on a pilot scale. Preliminary tests provided the water dose to form a stable and compact agglomerate of 89 L per ton of ore and an acid dosage of 40 kg per ton of ore. The column leaching method resulted in an effluent with 1.63 g/L Cu, a pH of 1.04, and a redox potential of 675 mV (average). Despite the similarities observed in the results, reductant agents were essential to dissolve the MnO4 present in the black copper ore. Thus, the best Mn extraction results were 67.7% using the MnO2:FeSO4 ratio of 1:3. Additionally, the kinetics of leaching are slower than in an industrial operation. The copper ore under study required more than 65 days of leaching to reach the maximum copper recovery. Finally, the total recovery of copper (including washing and resting time) indicates that the maximum value was re... [more]

To accurately evaluate the size and distribution characteristics of the emission particles exhausted from in-use motor vehicle engines, we independently developed a condensation particle counter (CPC) known as BHCPC. It was calibrated by conducting the calibration procedures stated in the International Standard ISO 27981. After calibration, we conducted on-site measurements and offline sampling analysis of soot particles exhausted from different engines at a motor vehicle inspection center. The calibration results show that the detection efficiency is 90% when the particle diameter is 20.6 nm and the startup response time of the instrument is 3.53 s. The experiment results show that the self-developed BHCPC demonstrates good consistency in measuring particle-number concentration (PNC) in motor vehicle exhaust, with significant count fluctuations only occurring when PNC is higher than 25,000 P/cc. Under idle conditions, motor vehicles compliant with China VI emission regulations exhibit... [more]

A combined approach of Latin hypercube sampling and K-means clustering is proposed in this study to address the uncertainty issue in wind and solar power output. Furthermore, the loads are categorized into three levels: primary load, secondary load, and tertiary load, each with distinct characteristics in terms of demand. Additionally, a load demand response characteristic model is developed by incorporating the dissatisfaction coefficient of electric and thermal loads, which is then integrated into the system’s operational costs. Moreover, an electricity−hydrogen−thermal power system is introduced, and a source-load coordination response mechanism is proposed based on the different levels of demand response characteristics. This mechanism enhances the interaction capability between the power sources and loads, thereby further improving the economic performance of the virtual power plant. Furthermore, the operation economy of the virtual power plant is enhanced by considering the parti... [more]

Solid−liquid separation is a fundamental operation in process engineering and thus an important part of many process chains in the preparation of slurries in the chemical industry and other parts of the industrial environment. For the separation of micron-sized particles which, due to their size, do not settle or settle very slowly in the earth’s gravity field, centrifuges are often used. The preferred choice are often decanter centrifuges because they work continuously and stabilize the process against product fluctuations due to their adjustment possibilities. The design of the apparatus is complex: The main components of the apparatus are the cylindrical-conical bowl, which rotates at a high speed, and a screw located inside the bowl, which rotates in the same direction at a low differential speed to transport the separated solids out of the apparatus. Geometrical properties of the apparatus, as well as the adjustable operating parameters, such as rotational speed or differential sp... [more]

This paper presents a methodology for predicting the remaining usability of rolling bearings. The method combines a fully adaptive ensemble empirical modal decomposition of noise (CEEMDAN), convolutional neural network (CNN), and attention bidirectional long short-term memory network (ABiLSTM). Firstly, a finite number of intrinsic mode functions (IMFs) are obtained from breaking down the initial vibration signals using CEEMDAN. The IMFs are further screened by combining the correlation criterion and the craggy criterion. Then, time-frequency domain features, which are extracted from the screened IMFs, are reconstructed into a feature set. The SPT is recognized through some features, like the root mean square (RMS), variance, and kurtosis. Secondly, the deterioration character of rolling bearings was extracted using CNN and used to train the ABiLSTM network. Based on the output of the ABiLSTM network, it forecasts how long rolling bearings will last during use. Finally, the XJTU-SY rol... [more]

This study explores the progression of global healthcare and medical waste (HMW) disposal technologies and emerging practices in China including the COVID-19 pandemic period through patent technology innovation analysis. Trends were identified through both the Derwent Innovation Index database and bibliometric methods. Based on the bibliometric analysis of 4128 patents issued from 2002 to 2021, the development status and research trends of HMW disposal technology were revealed. Regarding patents, China significantly advanced post-2011. However, a large number of applications are filed only in China and are more focused on domestic rather than overseas markets. As the pandemic remains a threat, and increasing amounts of medical waste are generated, new technologies are being sought in China that will be safer for humans and the environment, and will also be in line with the zero waste technology trend. Incineration and waste crushing are core methodologies in medical waste disposal. Fut... [more]

Oil lubricates the contact between the orbiting and stationary scroll in the refrigerant scroll compressor, while the sealing between the scrolls is achieved through the refrigerant vapour pressure in the sealed back pressure chamber. The back pressure should be adjusted using the refrigerant oil two-phase flow from the oil separator at the compressor discharge to the back pressure chamber and the refrigerant oil flow from the back pressure chamber to the compressor suction side. Both of the flows are conducted through connecting tubes with corresponding high-pressure and low-pressure nozzles with small diameters. Models for predicting the refrigerant oil critical and subcritical flows through the nozzles were developed and applied in enable the prediction of the back pressure. The models are original, because the slip between the oil and the refrigerant as well as the refrigerant solubility in the oil are taken into account. The critical flow model is validated against the experimenta... [more]

In this paper, in order to reduce the spindle temperature rise and enhance the spindle heat dissipation capability, a top complementary heat conductive path of the spindle based on the IPTO algorithm was designed. In order to verify the heat dissipation effect of the heat conductive path, an experimental test platform was constructed. Experiments on the thermal characteristics of water-cooled and air-cooled heat conductive paths with different volume proportions were conducted to test the temperature rise of the spindle and analyze the effect of the heat conductive path with different volume proportions on the temperature distribution of the spindle. The heat conductive path with the optimal volume proportion was determined and the heat dissipation effect of the heat conductive path was verified.

A Distributed Control System is a concept of Network Control Systems whose applications range from industrial control systems to the control of large physical experiments such as the ALICE experiment at CERN. The design phase of the Distributed Control Systems implementation brings several challenges, such as predicting the throughput and response of the system in terms of data-flow. These parameters have a significant impact on the operation of the Distributed Control System, and it is necessary to consider them when determining the distribution of software/hardware resources within the system. This distribution is often determined experimentally, which may be a difficult, iterative process. This paper proposes a methodology for modeling Distributed Control Systems using a combination of Finite-State Automata and Petri nets, where the resulting model can be used to determine the system’s throughput and response before its final implementation. The proposed methodology is demonstrated... [more]

The agricultural sector is one that requires and consumes enormous amounts of fresh water globally. Commercial wine production in particular uses large volumes of fresh water and, through various processes, generates significant quantities of wastewater. The wastewater produced by wineries typically exhibits elevated levels of chemical oxygen demand (COD), total suspended solids (TSS), an acidic pH, and varying salinity and nutrient contents. The overall characteristics of winery wastewater indicate that it is a potential environmental hazard if not processed and disposed of appropriately. Due to significant variations in wastewater contaminant levels among wineries, the implementation of a universally applicable, environmentally friendly, and sustainable waste management system seems practically unattainable. This study investigated the design, fabrication, and modification of a shear enhanced flotation separation (SEFS) pilot plant to be used as a primary treatment stage during winer... [more]

This study establishes an enzymatic membrane-coupled production process for antioxidant peptides from Carya cathayensis cake by comparing the effects of not feeding, water feeding, substrate feeding, and gradient dilution feeding supplementary material modes, to assess their impact on production efficiency. The optimal operational conditions were determined as follows: pH 10.5, temperature 50 °C, and enzyme-to-substrate ratio of 10% (w/w). The continuous production using the gradient dilution supplementary material mode resulted in Chinese pecan antioxidant peptides with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate of 0.044 mg/mL, 2, 2-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) radical scavenging rate of 0.518 mg/mL, and ferrous ion chelating ability (IC50) of 0.252 mg/mL. Compared with traditional enzymatic hydrolysis processes, the gradient dilution supplementary material enzymatic membrane-coupled production process increased peptide yield, peptide productio... [more]

Pressure-driven water injection technology shows significant potential in addressing the key challenges of low-permeability oil reservoirs, improving water flooding development efficiency. Grounded in FDEM theory, this study establishes fluid matrix constitutive equations and employs FDEM to resolve rock stress−strain fields. A numerical simulation method for pressure-driven water injection in low-permeability reservoirs is developed to study the impact of different well pattern densities. The results indicate that the 90° horizontal well pattern using the five-spot method yields optimal outcomes, with approximately 32.32% higher cumulative liquid production than vertical well patterns. The 45° horizontal well pattern with the reversed nine-spot method also performs well, with about 30% higher cumulative liquid production than single-row vertical wells. Pressure-driven water injection improves matrix oil−water permeability and expands water flooding coverage. Based on the pressure grad... [more]