Processes, Volume 9, Issue 7 (July 2021) – 177 articles

In this paper, a new Lagrange relaxation based decomposition algorithm for the integrated offshore oil production planning optimization is presented. In our previous study (Gao et al. Computers and Chemical Engineering, 2020, 133, 106674), a multiperiod mixed-integer nonlinear programming (MINLP) model considering both well operation and flow assurance simultaneously had been proposed. However, due to the large-scale nature of the problem, i.e., too many oil wells and long planning time cycle, the optimization problem makes it difficult to get a satisfactory solution in a reasonable time. As an effective method, Lagrange relaxation based decomposition algorithms can provide more compact bounds and thus result in a smaller duality gap. Specifically, Lagrange multiplier is introduced to relax coupling constraints of multi-batch units and thus some moderate scale sub-problems result. Moreover, dual problem is constructed for iteration. As a result, the original integrated large-scale model is decomposed into several single-batch subproblems and solved simultaneously by commercial solvers. Computational results show that the proposed method can reduce the solving time up to 43% or even more. Meanwhile, the planning results are close to those obtained by the original model. Moreover, the larger the problem size, the better the proposed LR algorithm is than the original model. Full article

The application of splitter blades can improve passage obstructions and reduce flow loss of small-scale organic Rankine cycle (ORC) radial inflow turbines. In this study, taking R245fa as the working fluid, splitter blades are applied to design an impeller layout for a 10 kW ORC radial inflow turbine, and numerical simulation is conducted on different impeller schemes through Fluent 15.0. The influence of the meridian length and circumferential position of the splitter blade on the performance of the turbine impeller is studied. The results show that the meridian length and circumferential position of the splitter blade exert greater effects on the flow field distribution inside the impeller and the impeller performance. When the circumferential offset of the splitter blade is around 0.6 and the blade length is around 80% of the length of main blade, the ORC radial inflow turbine designed in this study reaches optimum performance, and its performance is better than the traditional impeller. Full article

Dynamic lotsizing and scheduling on multiple lines to meet the customer due dates is significant in multi-line production environments. Therefore, this study investigates dynamic lotsizing and scheduling problems in multiple flexible machining lines considering mixed products. In addition, uncertainty in demand and machine failure is considered. A mathematical model is proposed for the considered problem with an aim to maximize the probability of completion of product models from different customer orders. A constructive heuristic method (CHLP) is proposed to solve the current problem. The proposed heuristic involves the steps to distribute different customer order demands among multiple lines and schedule them considering balancing of makespan between the lines. The performance of CHLP is measured with famous heuristics from the literature, based on the test problem instances. Results indicate that CHLP gives better results in terms of quality of results as compared to other famous literature heuristics. Full article

The incidence and mortality rate of lung cancer is the highest in Xuanwei County, Yunnan Province, China. The mechanisms of the high lung incidence remain unclear, necessitating further study. However, the particle size distribution characteristics of HULIS emitted from residential coal combustion (RCC) have not been studied in Xuanwei. In this study, six kinds of residential coal were collected. Size-resolved particles emitted from the coal were sampled by using a burning system, which was simulated according to RCC made in our laboratory. Organic carbon (OC), elemental carbon (EC), water-soluble inorganic ion, water-soluble potentially toxic metals (WSPTMs), water-soluble organic carbon (WSOC), and HULIS-C (referred to as HULIS containing carbon contents) in the different size-segregated particulate matter (PM) samples were determined for health risk assessments by inhalation of PM. In our study, the ratio of HULIS-Cx to WSOCx values in RCC particles were 32.73–63.76% (average 53.85 ± 12.12%) for PM_2.0 and 33.91–82.67% (average 57.06 ± 17.32%) for PM_2.0~7.0, respectively. The carcinogenic risks of WSPTMs for both children and adults exceeded the acceptable level (1 × 10⁻⁶, indicating that we should pay more attention to these WSPTMs). Exploring the HULIS content and particle size distribution of the particulate matter produced by household coal combustion provides a new perspective and evidence for revealing the high incidence of lung cancer in Xuanwei, China. Full article

In the current numerical study, various wall shape effects are investigated on the thermal-hydraulic characteristics of different channels filled with water-based graphite-SiO₂ hybrid nanofluid. In this work, the performance evaluation criteria (PEC) index is employed as the target parameter to attain optimum geometry. Six different cases are studied in this research, and each case has different geometrical dimensions. The inlet temperature for the fluids in the channel is 300 K, over a range of different flow velocities. According to the obtained results, an increase in the volume fraction of nanoparticles results in higher PEC values. In addition, an increase in Reynolds number to Re = leads to an increase in the PEC index. The results clearly show that increasing the Reynolds number has two consequences: on the one hand, it increases the pressure drop penalty; on the other hand, it improves heat transfer. Therefore, the maximum value of the PEC index occurs at Re = 15,000. Full article

Maritime transport is investigating several options to reduce its greenhouse gases and air pollutant emissions. An experimental ship, Energy Observer, is using excess renewable energy to generate onboard hydrogen by electrolysis of purified seawater. As a promising option for storing energy, it can provide on-demand energy to the ship through a hydrogen fuel cell (FC). As hydrogen FCs lifetime and performance are correlated to hydrogen quality, the hydrogen produced onboard needs to be monitored. This study assesses the probability of contaminants presence for this electrolyser, using purified seawater and supports the results with a hydrogen fuel quality analysis from the Energy Observer ship. It demonstrates that an electrolyser using onboard purified seawater can generate hydrogen of a quality compliant with ISO 14687:2019. Additional contaminants (i.e., ions, heavy metal) were also measured. The study highlights the potential contaminants to be monitored and future research on new contaminants from seawater to further develop hydrogen fuel for maritime applications. Full article

Using experimental data for the adsorption of phosphates out of wastewater on waste recycled bricks, published independently in MDPI Processes before (2020), this message re-visits the mathematical theory of the Freundlich adsorption model. It demonstrates how experimental data are to be deeper treated to model the saturation regime and to bridge a chasm between those areas where the data fit the Freundlich power function and where a saturation of surface adsorption centers occurs. Full article

The simulation of carbon dioxide (CO₂)-methane (CH₄) mixed gas adsorption and the selectivity on zeolite 4A using Aspen Adsorption were studied. The influence of temperature ranging from 273 to 343 K, pressure up to 10 bar and various compositions of CO₂ in the binary system were simulated. The findings of the study demonstrate that the models are accurate. In addition, the effects of various key parameters such as temperature, pressure, and various compositions of binary gases were investigated. The highest CO₂ and CH₄ adsorption are found at 273 K and 10 bar in the Langmuir isotherm model with 5.86 and 2.88 mmol/g, respectively. The amount of CO₂ adsorbed and the selectivity of the binary mixture gas depends on the composition of CO₂. The kinetics of adsorption for pure components of CO₂ at high temperatures can reach saturation faster than CH₄. The influence of the physical properties of zeolite 4A on kinetic adsorption were also studied, and it was observed that small adsorbent particles, large pore diameter, and large pore volume would enter saturation quickly. The prediction of CO₂-CH₄ mixed gas adsorption and selectivity on zeolite 4A were developed for further use for commercial gas separation. Full article

The aim of this work is to identify the effect of the CaO phase as a CO₂ sorbent and mayenite (Ca₁₂Al₁₄O₃₃) as a stabilizing phase in a bi-functional material for CO₂ capture in biomass syngas conditioning and cleaning at high temperature. The effect of different CaO weight contents is studied (0, 56, 85, 100 wt%) in sorbents synthesized by the wet mixing method. These high temperature solid sorbents are upgraded to bi-functional compounds by the addition of 3 or 6 wt% of nickel chosen as the metal active phase. N₂ adsorption, X-ray diffraction, scanning electronic microscopy, temperature-programmed reduction analyses and CO₂ sorption study were performed to characterize structural, textural, reducibility and sorption properties of bi-functional materials. Finally, sorption-enhanced reforming of toluene (chosen as tar model), of methane then of methane and toluene with bi-functional compounds were performed to study the best material to improve H₂ content in a syngas, provided by steam biomass gasification. If the catalytic activity on the sorption enhanced reforming of methane exhibits a fast fall-down after 10–15 min of experimental test, the reforming of toluene reaches a constant conversion of 99.9% by using bi-functional materials. Full article

This paper reviews actual sustainability assessments in the construction sector to define whether and how a Life Cycle Sustainability Assessment (LCSA) is applied and interpreted in this sector today. This industry has large shares in global energy (33%), raw material consumption (40%) and solid waste generation (40%). Simultaneously, it drives the economy and provides jobs. The LCSA is a method to identify environmental, social and economic impacts of products/services along their life cycles. The results of this study showed a mismatch between sectoral emissions and the number of LCSA-based impact evaluations. It was found that only 11% of papers reviewed assessed all three sustainability pillars. The economic and especially the social pillars were partly neglected. In Life Cycle Assessments (LCAs), 100% made use of Global Warming Potential (GWP) but only 30% assessed more than five indicators in total. In Life Cycle Costing (LCC), there were a variety of costs assessed. Depreciation and lifetime were mainly neglected. We found that 42% made use of Net Present Value (NPV), while over 50% assessed individual indicators. For the Social Life Cycle Assessment (S-LCA), the focus was on the production stage; even the system boundaries were defined as cradle-to-use and -grave. Future approaches are relevant but there is no need to innovate: a proposal for a LCSA approach is made. Full article

The exponential increase of the human population demands the overuse of fertilizers and pesticides in agriculture practices to suppress food production needs. The excessive use of these chemicals (fertilizers and pesticides) can comport deleterious effects to the ecosystems, including aquatic systems and communities. Oxyfluorfen is a fluorine-based herbicide, and its application has increased, since it is seen as an alternative to control glyphosate-resistant weeds. Copper sulfate is an inorganic pesticide based on copper which is being used in several chemical formulations, and it is the second main constituent of fungicides. Besides the known effects of such products in organisms, climatic changes pose an additional issue, being a main concern among scientists and politicians worldwide, since these alterations may worsen ecosystems’ and organisms’ sensitivity to stress conditions, such as the exposure to pollutants. Thalassiosira weissflogii (Grunow) G. A. Fryxell & Hasle, 1977 plays an important role in aquatic food webs as a primary producer and an essential food source to zooplankton. Thus, alterations on the diatom’s abundance and nutritional value may lead to consequences along the trophic chain. However, few studies have evaluated the biochemical impacts of oxyfluorfen and copper sulfate exposure on diatoms. This study intends to (1) evaluate the effects on the growth rate of both contaminants on T. weissfloggi at three temperatures, considering the actual scenario of climatic changes, and (2) assess biochemical changes on the diatom when exposed to the chemicals at different temperatures. To achieve these aims, the marine diatom was exposed to the two chemicals individually at different temperatures. The results showed an increase in the growth rate with increasing temperatures. Oxyfluorfen exhibited higher toxicity than copper sulfate. At the biochemical level, the microalgae were greatly affected when exposed to oxyfluorfen at 20 °C and 25 °C and when exposed to copper sulfate at 15 °C. Moreover, a general increase was observed for the polysaccharide content along the copper sulfate and oxyfluorfen concentrations. Therefore, the contaminants show the ability to interfere with the diatom growth and the nutritive value, with their effects dependent on the temperature. Full article

Nowadays, there is a great development in electric vehicle production and utilization. It has no pollution, high efficiency, low noise, and low maintenance. However, the charging stations, required to charge the electric vehicle batteries, impose high energy demand on the utility grid. One way to overcome the stress on the grid is the utilization of renewable energy sources such as photovoltaic energy. The utilization of standalone charging stations represents good support to the utility grid. Nevertheless, the electrical design of these systems has different techniques and is sometimes complex. This paper introduces a new simple analysis and design of a standalone charging station powered by photovoltaic energy. Simple closed-form design equations are derived, for all the system components. Case-study design calculations are presented for the proposed charging station. Then, the system is modeled and simulated using Matlab/Simulink platform. Furthermore, an experimental setup is built to verify the system physically. The experimental and simulation results of the proposed system are matched with the design calculations. The results show that the charging process of the electric vehicle battery is precisely steady for all the PV insolation disturbances. In addition, the charging/discharging of the energy storage battery responds perfectly to store and compensate for PV energy variations. Full article

Diabetes mellitus (DM), as a chronic disease caused by insulin deficiency or using obstacles, is gradually becoming a principal worldwide health problem. Pueraria lobata is one of the traditional Chinese medicinal and edible plants, playing roles in improving the cardiovascular system, lowering blood sugar, anti-inflammation, anti-oxidation, and so on. Studies on the hypoglycemic effects of Pueraria lobata were also frequently reported. To determine the active ingredients and related targets of Pueraria lobata for DM, 256 metabolites were identified by LC/MS non targeted metabonomics, and 19 active ingredients interacting with 51 DM-related targets were screened. The results showed that puerarin, quercetin, genistein, daidzein, and other active ingredients in Pueraria lobata could participate in the AGE-RAGE signaling pathway, insulin resistance, HIF-1 signaling pathway, FoxO signaling pathway, and MAPK signaling pathway by acting on VEGFA, INS, INSR, IL-6, TNF and AKT1, and may regulate type 2 diabetes, inflammation, atherosis and diabetes complications, such as diabetic retinopathy, diabetic nephropathy, and diabetic cardiomyopathy. Full article

In this study, changes in hydrophobic interactions among gluten proteins were analyzed during dough mixing. Size-exclusion high-performance chromatography and two-dimensional fluorescence difference gel electrophoresis were performed on proteins extracted with 1-propanol by weakening the hydrophobic interaction. The amount of proteins extracted with 30% 1-propanol increased from the start of mixing to peak consistency, suggesting that the hydrophobic interactions among the strongly aggregated proteins weakened and resulted in disaggregation. The amount of proteins extracted with 10% 1-propanol decreased during hydration, indicating that these proteins aggregated through relatively weak hydrophobic interactions. The proteins that extractability decreased were mainly low molecular weight glutenin, α-gliadin, and γ-gliadin. The amount of monomeric proteins extracted with 30% 1-propanol decreased after peak consistency. The decreased protein was mainly ω-gliadin, indicating that ω-gliadin aggregated with other proteins through hydrophobic interactions. A front-face fluorescence analysis was performed on the dough with the addition of 8-anilino-1-naphthalenesulfonic acid or thioflavin T. The fluorescence intensity increased as a result of exposure to the hydrophobic groups of the gluten proteins and the formation of protein aggregates during dough mixing. These results indicate the importance of hydrophobic interactions in dough formation. Full article

Due to the numerous side effects of synthetic pesticides, including environmental pollution, threats to human health, harmful effects on non-target organisms and pest resistance, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. In this paper, the susceptibility of the cosmopolitan, polyphagous, stored-product pest Tribolium castaneum (red flour beetle) to the fumigation of the essential oils of two important medicinal and food additive plants, Satureja hortensis and S. intermedia, was investigated. The insecticidal properties of the essential oils were modeled and optimized using response surface methodology. It was found that a maximum significant mortality of 94.72% and 92.97% could be achieved within 72 h with the applications of 55.15 µL/L of S. hortensis (with the linear model) and 58.82 µL/L of S. intermedia (with the quadratic model), respectively. There were insecticidal terpenes and phenylpropanoids in both essential oils, including thymol (50.8%), carvacrol (11.2%) and p-cymene (13.4%), in the S. intermedia and estragole (68.0%) and methyl eugenol (5.6%) in the S. hortensis. It was suggested that the essential oils of S. hortensis and S. intermedia could be offered as promising pesticidal agents against T. castaneum for further studies in the management of such pests instead of detrimental synthetic pesticides. Full article

Ischemic heart disease (or Coronary Artery Disease) is the most common cause of death in various countries, characterized by reduced blood supply to the heart. Statistical models make an impact in evaluating the risk factors that are responsible for mortality and morbidity during IHD (Ischemic heart disease). In general, geometric or Poisson distributions can underestimate the zero-count probability and hence make it difficult to identify significant effects of covariates for improving conditions of heart disease due to regional wall motion abnormalities. In this work, a flexible class of zero inflated models is introduced. A Bayesian estimation method is developed as an alternative to traditionally used maximum likelihood-based methods to analyze such data. Simulation studies show that the proposed method has a better small sample performance than the classical method, with tighter interval estimates and better coverage probabilities. Although the prevention of CAD has long been a focus of public health policy, clinical medicine, and biomedical scientific investigation, the prevalence of CAD remains high despite current strategies for prevention and treatment. Various comprehensive searches have been performed in the MEDLINE, HealthSTAR, and Global Health databases for providing insights into the effects of traditional and emerging risk factors of CAD. A real-life data set is illustrated for the proposed method using WinBUGS. Full article

The high quality of Port wine is the result of a sequence of winemaking operations, such as harvesting, maceration, fermentation, extraction and aging. These stages require proper monitoring and control, in order to consistently achieve the desired wine properties. The present work focuses on the harvesting stage, where the sugar content of grapes plays a key role as one of the critical maturity parameters. Our approach makes use of hyperspectral imaging technology to rapidly extract information from wine grape berries; the collected spectra are fed to machine learning algorithms that produce estimates of the sugar level. A consistent predictive capability is important for establishing the harvest date, as well as to select the best grapes to produce specific high-quality wines. We compared four different machine learning methods (including deep learning), assessing their generalization capacity for different vintages and varieties not included in the training process. Ridge regression, partial least squares, neural networks and convolutional neural networks were the methods considered to conduct this comparison. The results show that the estimated models can successfully predict the sugar content from hyperspectral data, with the convolutional neural network outperforming the other methods. Full article

Tea polyphenols (TP) are a widely acknowledged bioactive natural product, however, low stability and bioavailability have restricted their application in many fields. To enhance the stability and bioavailability of TP under certain moderate conditions, encapsulation technique was applied. Kappa–Carrageenan (KCG) was initially degraded to a lower molecular weight KCG (LKCG) by H₂O₂, and was selected as wall material to coat TP. The obtained LKCG (Mn = 13,009.5) revealed narrow dispersed fragments (DPI = 1.14). FTIR and NMR results demonstrated that the main chemical structure of KCG remained unchanged after degradation. Subsequently, LK-CG and TP were mixed and homogenized to form LK-CG-TP microspheres. SEM images of the microspheres revealed a regular spherical shape and smooth surface with a mean diameter of 5–10 μM. TG and DSC analysis indicated that LK-CG-TP microspheres exhibited better thermal stability as compared to free TP. The release profile of LK-CG-TP in simulated gastric fluid (SGF) showed a slowly release capacity during the tested 180 min with the final release rate of 88.1% after digestion. Furthermore, in vitro DPPH radical scavenging experiments revealed that LK-CG-TP had an enhanced DPPH scavenging rate as compared to equal concentration of free TP. These results indicated that LK-CG-TP microspheres were feasible for protection and delivery of TP and might have extensive potential applications in other bioactive components. Full article

To study the movement characteristics and separation mechanism of safflower petals and their impurities under the action of airflow and lower the impurity rate in the cleaning operation process, integration of computational fluid dynamics (CFD) and discrete element method (DEM) codes was performed to study the motion and sorting behavior of impurity particles and safflower petals under different airflow inclination angles, dust removal angles and inlet airflow velocities by establishing a true particle model. In this model, the discrete particle phase was applied by the DEM software, and the continuum gas phase was described by the ANSYS Fluent software. The Box-Behnken experimental design with three factors and three levels was performed, and parameters such as inlet airflow velocity, airflow inclined angle, and dust remover angle were selected as independent variables that would influence the cleaning impurity rate and the cleaning loss rate. A mathematical model was established, and then the effects of various parameters and their interactions were analyzed. The test results show that the cleaning effect is best when the inlet airflow velocity is 7 m/s, the airflow inclined angle is 0°, and the dust remover angle is 25°. Confirmatory tests showed that the average cleaning impurity rate and cleaning loss rate were 0.69% and 2.75%, respectively, which dropped significantly compared with those from previous optimization. An experimental device was designed and set up; the experimental results were consistent with the simulation results, indicating that studying the physical behavior of safflower petals-impurity separation in the airflow field by using the DEM-CFD coupling method is reliable. This result provides a basis for follow-up studies of separation and cleaning devices for lightweight materials such as safflower petals. Full article

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m²/g and NV-Na 19.0(4) to 158(7) m²/g. ²⁹Si and ²⁷Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K⁺ ion pretreatment in the HCl modified zeolites. Full article

Biological municipal wastewater treatments lead to high sludge generation and long retention times, and the possibilities for recovery of the energy content of the input waste stream are very limited due to the low operating temperature. As an alternative, we propose a sequence of exclusively physicochemical, non-biological stages that avoid sludge production, while producing high-grade energy outflows favoring recovery, all in shorter times. Ultrafiltration and evaporation units provide a front-end concentration block, while a supercritical water oxidation reactor serves as the main treatment unit. A new approach for energy recovery from the effluent of the reactor is proposed, based on its injection in a gas turbine, which presents advantages over simpler direct utilization methods from operational and efficiency points of view. A process layout and a numerical simulation to assess this proposal have been developed. Results show that the model process, characterized with proven operating parameters, found a range of feasible solutions to the treatment problem with similar energy costs, at a fast speed, without sludge production, while co-generating the municipality’s average electricity consumption. Full article

Point-of-care diagnostic devices that are rapid and reliable remain as an unmet need highlighted by the coronavirus disease (COVID-19) pandemic crisis. The second/third wave of virus spread in various parts of the world combined with new evidence of re-infections and inadequate healthcare facilities demand increased testing rate to diagnose COVID-19 at its core. Although traditional molecular diagnostic tests have served this purpose, there have been shortage of reagents and other supplies at pandemic frontlines. This calls for novel alternate diagnostic processes with potential for obtaining emergency use authorization and that can be deployed in the field at the earliest opportunity. Here, we show an ultra-fast SARS-CoV-2 detection sensor for detecting coronavirus proteins in saliva within 100 milliseconds. Electrochemical oxidation of nickel hydroxide has been controlled using cyclic voltammetry and chronoamperometry techniques for successful detection of SARS-CoV-2. Test results have proven the capability of sensors to quantitatively detect the concentration of virus in blinded analyses. The detection occurs by a process similar to that of SARS-CoV-2 binding onto host cells. The sensor also shows prospects in distinguishing SARS-CoV-2 from other viruses such as HIV. More importantly, the sensor matches the detection limit of the gold standard test for diagnosing early infection. The use of saliva as a non-invasive sampling technique combined with the portability of the instrument has broadened the potential of this sensor. Full article

In the product life cycle from conception to retirement, there are three forms: conceptual products, digital products and physical products. The carriers of conceptual products are requirements, functions and abstract structures, and data management focuses on the mapping of requirements, functions, and structures. The carrier of digital products is digital files such as drawings and models, and the focus of data management is the design evolution of product. Physical products are physical entities, and their attributes and states will change over time. Existing data model research often focuses on one or two forms, and it is even impossible to integrate three forms of data into one system. So, a new data management method based on product form is presented. According to the characteristics of the three product form data, a conceptual product data model, a digital product data model, and a physical product data model are established to manage the three forms of data, respectively, and use global object mapping to integrate them into a unified data model. The conceptual product data model has a single data model for a single business stage. The digital product data model uses the core data model as the single data source, and uses one stage rule filter to add constraints to the core data model for each business stage. The physical product data model uses the core data model to manage the public data of the physical phase, and the phase private data model focuses on the private data of each business phase. Finally, a case of Multi-Purpose Container Vessel is studied to verify the feasibility of the method. This paper proposes three product forms of product data management and a unified data management model covering the three product forms, which provides a new method for product life cycle data. Full article

Efficient conversion of renewable biomass into value-added chemicals and biofuels is regarded as an alternative route to reduce our high dependence on fossil resources and the associated environmental issues. In this context, biomass-based furfural and levulinic acid (LA) platform chemicals are frequently utilized to synthesize various valuable chemicals and biofuels. In this review, the reaction mechanism and catalytic system developed for the generation of furfural and levulinic acid are summarized and compared. Special efforts are focused on the different catalytic systems for the synthesis of furfural and levulinic acid. The corresponding challenges and outlooks are also observed. Full article

A performance assessment of wave power absorption characteristics of isolated and multiple wave energy converter (WEC) rotors was presented in this study for various wave-heading angles and wave frequencies. Numerical hydrodynamic analysis of the WEC was carried out using the three-dimensional linear boundary element method (BEM) and nonlinear computational fluid dynamics (CFD). Experimental results were used to validate the adopted numerical models. Influence with and without power take-off (PTO) was estimated on both isolated and multiple WEC rotors. Furthermore, to investigate the interaction effect among WECs, a q-factor was used. Incorporation of viscous and PTO damping into the linear BEM solution shows the maximum reduction focused around peak frequency but demonstrated an insignificant effect elsewhere. The q-factor showed both constructive and destructive interactions with the increase of the wave-heading angle and wave frequencies. Further investigation based on the prototype WEC rotor was carried, and calculated results of the linear BEM and the nonlinear CFD were compared. The pitch response and q-factor of the chosen wave frequencies demonstrated satisfactory consistency between the linear BEM and nonlinear CFD results, except for some wave frequencies. Estimated optimal time-averaged power using linear BEM show that the maximum extracted power close to the zero wave-heading angle around the resonance frequency decreases as the wave-heading angle increases. Overall, the linear BEM on the extracted power is overestimated compared with the nonlinear CFD results. Full article

The bullwhip effect results from inefficiencies in the supply chain; in perishable products, the inefficiencies are quality in the supply chain and product waste. We carried out a literature review to determine the causes of the bullwhip effect and the supply chain’s quality factors of this phenomenon’s perishable products. Update the demand, the level of deterioration of the product, and the number of intermediaries is the causes of the bullwhip effect most investigated. On the other hand, the product’s safety and the quality of the information are the quality factors of the chain of supplies of perishable products more researched. Future research should address the causes of human behavior that affect the bullwhip effect in the perishable goods supply chain. Full article

An adventitious flow field has a great impact on the operational reliability of pumps; therefore, it is important to study pump flow characteristics to reduce the noise, vibration, and cavitation performance of pumps. To study the pressure fluctuation characteristics of the hose pump, a three-dimensional two-way fluid structure coupling model of the hose pump was established. The transient structural module, fluid flow (fluent) module, and system coupling module of ANSYS Workbench 19.0 were used to simulate the unsteady multiple working conditions of the hose pump. The accuracy and reliability of the calculation results from the fluid solid coupling simulation were verified via experimentation. The results show that the roller pass frequency is the main frequency of the pressure fluctuation at the outlet of the hose pump. When the plane of the deformation recovery area is small, the pressure pulsation amplitude is large, and the outlet pressure and speed are large. Due to the irregular backflow of the fluid, stall zones of different sizes form, the outlet pressure is closer to a sinusoid when there is no pressure. The higher the rotating speed is, the faster the pressure roller leaving the hose, the higher the pressure pulsation, and the larger the stall zone. Therefore, the best way to reduce the pressure pulsation in the pump is to optimize the geometry of the pressure roller and change the outlet angle of the hose. Full article

A novel parametric control method for the compressor blade, the full-blade surface parametric method, is proposed in this paper. Compared with the traditional parametric method, the method has good surface smoothness and construction convenience while maintaining low-dimensional characteristics, and compared with the semi-blade surface parametric method, the proposed method has a larger degree of geometric deformation freedom and can account for changes in both the suction surface and pressure surface. Compared with the semi-blade surface parametric method, the method only has four more control parameters for each blade, so it does not significantly increase the optimization time. The effectiveness of this novel parametric control method has been verified in the aerodynamic optimization field of compressors by an optimization case of Stage35 (a single-stage transonic axial compressor) under multi-operating conditions. The optimization case has brought the following results: the adiabatic efficiency of the optimized blade at design speed is 1.4% higher than that of the original one and the surge margin 2.9% higher, while at off-design speed, the adiabatic efficiency is improved by 0.6% and the surge margin by 1.3%. Full article

To improve our understanding of the interactive effects in combustion of binary multicomponent fuel droplets at sub-atmospheric pressure, combustion experiments were conducted on two fibre-supported RP-3 kerosene droplets at pressures from 0.2 to 1.0 bar. The burning life of the interactive droplets was recorded by a high-speed camera and a mirrorless camera. The results showed that the flame propagation time from burning droplet to unburned droplet was proportional to the normalised spacing distance between droplets and the ambient pressure. Meanwhile, the maximum normalised spacing distance from which the left droplet can be ignited has been investigated under different ambient pressure. The burning rate was evaluated and found to have the same trend as the single droplet combustion, which decreased with the reduction in the pressure. For every experiment, the interactive coefficient was less than one owing to the oxygen competition, except for the experiment at L/D₀ = 2.5 and P = 1.0 bar. During the interactive combustion, puffing and microexplosion were found to have a significant impact on secondary atomization, ignition and extinction. Full article

Effects of fermentation on the chemical composition, mineral, total phenolic, total flavonoid, tannin, vitamin C, total carotenoid content, and antioxidant activity of “Nabag” Ziziphus spina-christi (L.) seeds were investigated. The fermentation process was carried out for 6, 12, 24, and 48 h. The fermentation significantly (p < 0.05) improved the chemical composition and mineral content of “Nabag” seeds, particularly the Ca, Fe, and Zn content. The phenolic, vitamin C, total carotenoid content, and antioxidant activity were significantly (p < 0.05) increased as a result of fermentation compared with unfermented Ziziphus spina-christi (L.) seeds. Fermentation of the seeds for 48 h resulted in the highest increase in crude fiber, Ca, Fe, Zn, and bioactive compounds. These results indicate the potential utilization of fermented “Nabag” seeds in the production and formulation of functional foods rich in crude fiber, essential minerals, and bioactive compounds. Full article