Processes

14 pages, 64134 KiB

Open AccessArticle

Separation Characteristics of an Axial Hydrocyclone Separator

by Jie Kou, Zhaoming Jiang and Yiying Cong

Processes 2021, 9(12), 2288; https://doi.org/10.3390/pr9122288 - 20 Dec 2021

Cited by 4 | Viewed by 2853

An innovative axial hydrocyclone separator was designed in which a guide vane was installed to replace a conventional tangential inlet, potentially aggravating inlet turbulence. The characteristics of velocity distribution, concentration distribution, and pressure distribution inside the separator were obtained through the numerical simulation [...] Read more.

An innovative axial hydrocyclone separator was designed in which a guide vane was installed to replace a conventional tangential inlet, potentially aggravating inlet turbulence. The characteristics of velocity distribution, concentration distribution, and pressure distribution inside the separator were obtained through the numerical simulation of the turbulent flow of oil and water. The results showed that the flow field presented good symmetry, which eliminated the eccentric turbulence phenomenon in the conventional hydrocyclone separators and was beneficial for the oil–water separation. Full article

(This article belongs to the Topic Modern Technologies and Manufacturing Systems)

► Show Figures

Figure 1

15 pages, 1778 KiB

Open AccessFeature PaperArticle

The Influence of Surface Mycobiota on Sensory Properties of “Istarski pršut” and “Dalmatinski pršut”

by Tina Lešić, Nada Vahčić, Ivica Kos, Manuela Zadravec, Dragan Milićević, Irena Perković, Eddy Listeš and Jelka Pleadin

Processes 2021, 9(12), 2287; https://doi.org/10.3390/pr9122287 - 20 Dec 2021

Cited by 3 | Viewed by 2026

Abstract

This study aimed to identify surface mould species overgrowing the Croatian protected meat products “Istarski pršut” and “Dalmatinski pršut” and their effect on sensory properties. Dry-cured hams were produced in 2018/2019 and obtained from annual fairs. The predominant surface species found on “Dalmatinski [...] Read more.

This study aimed to identify surface mould species overgrowing the Croatian protected meat products “Istarski pršut” and “Dalmatinski pršut” and their effect on sensory properties. Dry-cured hams were produced in 2018/2019 and obtained from annual fairs. The predominant surface species found on “Dalmatinski pršut” were Aspergillus chevalieri, Penicillium citrinum and Aspergillus cibarius, whereas those overgrowing “Istarski pršut” were Aspergillus proliferans, P. citrinum and Penicillium salamii. The results show species diversity, higher presence, and greater variety of Aspergillus species in “Dalmatinski pršut” in comparison to “Istarski pršut”, and significant variations in 9 of 20 sensory attributes. Principal component analysis revealed a clear distinction between the two, and a large contribution of P. salamii and Penicillium bialowienzense to one principal component. The texture traits, smoky odour, muscle and subcutaneous fatty tissue colour, and mould species found are valuable for product characterisation. The results also indicate that mould species may be responsible for some sensory traits, such as tenderness, juiciness, and lesser freshness. Full article

(This article belongs to the Special Issue Study of Microbiological Safety in the Food Chain)

► Show Figures

Figure 1

16 pages, 776 KiB

Open AccessFeature PaperArticle

Semi-Natural and Spontaneous Speech Recognition Using Deep Neural Networks with Hybrid Features Unification

by Ammar Amjad, Lal Khan and Hsien-Tsung Chang

Processes 2021, 9(12), 2286; https://doi.org/10.3390/pr9122286 - 20 Dec 2021

Cited by 11 | Viewed by 2648

Abstract

Recently, identifying speech emotions in a spontaneous database has been a complex and demanding study area. This research presents an entirely new approach for recognizing semi-natural and spontaneous speech emotions with multiple feature fusion and deep neural networks (DNN). A proposed framework extracts [...] Read more.

Recently, identifying speech emotions in a spontaneous database has been a complex and demanding study area. This research presents an entirely new approach for recognizing semi-natural and spontaneous speech emotions with multiple feature fusion and deep neural networks (DNN). A proposed framework extracts the most discriminative features from hybrid acoustic feature sets. However, these feature sets may contain duplicate and irrelevant information, leading to inadequate emotional identification. Therefore, an support vector machine (SVM) algorithm is utilized to identify the most discriminative audio feature map after obtaining the relevant features learned by the fusion approach. We investigated our approach utilizing the eNTERFACE05 and BAUM-1s benchmark databases and observed a significant identification accuracy of 76% for a speaker-independent experiment with SVM and 59% accuracy with, respectively. Furthermore, experiments on the eNTERFACE05 and BAUM-1s dataset indicate that the suggested framework outperformed current state-of-the-art techniques on the semi-natural and spontaneous datasets. Full article

(This article belongs to the Special Issue Recent Advances in Machine Learning and Applications)

► Show Figures

Figure 1

12 pages, 42591 KiB

Open AccessArticle

Heat Transfer Performance of R-1234ze(E) with the Effect of High-Viscosity POE Oil on Enhanced GEWA-B5H Tube

by Abhishek Kumar, Miao-Ru Chen, Jung-Hsien Wu, Kuo-Shu Hung, Li-Kang Su and Chi-Chuan Wang

Processes 2021, 9(12), 2285; https://doi.org/10.3390/pr9122285 - 20 Dec 2021

Cited by 6 | Viewed by 2485

Abstract

In this study, the heat transfer performance of high-viscosity polyol ester (POE) oil POEA-220 (220 cSt) with low-GWP (global warming potential) refrigerant R-1234ze(E) on enhanced GEWA-B5H tube was investigated at saturation temperatures of 10 °C, 0 °C, and −6 °C. The mass fraction [...] Read more.

In this study, the heat transfer performance of high-viscosity polyol ester (POE) oil POEA-220 (220 cSt) with low-GWP (global warming potential) refrigerant R-1234ze(E) on enhanced GEWA-B5H tube was investigated at saturation temperatures of 10 °C, 0 °C, and −6 °C. The mass fraction of oil varied from 0.25% to 10%, and all the nucleate pool boiling data were measured at heat fluxes ranging from 10 kW/m² to 90 kW/m². The experimental results showed that the heat transfer performance of the R-1234ze(E)/POEA-220 mixtures were superior to the R-1234ze(E)/POEA-68 mixtures. At saturation temperatures of 0 °C and −6 °C, even a 10% mass fraction of the POEA-220 oil showed an enhancement in the HTC (heat transfer coefficient) compared to the pure refrigerant in the moderate heat flux range. On the other hand, for the R-1234ze(E)/POEA-68 mixtures, a 5% mass fraction of oil showed no enhancement in the HTC compared to pure refrigerant at the same saturation temperature. Moreover, at low saturation temperatures (0 °C and −6 °C), the enhancement in the HTC decreased with increasing mass fraction of low-viscosity oil POEA-68, whereas high-viscosity oil POEA-220 showed the highest enhancement in the HTC for a 5% mass fraction of oil at −6 °C saturation temperature compared to the pure refrigerant. The results indicate that for nucleate boiling, the effect of oil viscosity on heat transfer performance is negligible if it contains comparatively high thermal conductivity and low surface tension. In addition, the effect of surface aging on heat transfer performance for the GEAW-B5H tube with pure refrigerant was also reported. Full article

(This article belongs to the Special Issue Emerging Technologies in Heating, Ventilation, Air Conditioning and Refrigeration (HVAC&R) Systems)

► Show Figures

Figure 1

20 pages, 5835 KiB

Open AccessArticle

Response Surface Methodology (RSM)-Based Prediction and Optimization of the Fenton Process in Landfill Leachate Decolorization

by Anita Maslahati Roudi, Sultan Salem, Masoud Abedini, Amin Maslahati and Muhammad Imran

Processes 2021, 9(12), 2284; https://doi.org/10.3390/pr9122284 - 20 Dec 2021

Cited by 13 | Viewed by 2944

Abstract

As an advanced oxidative processes, the Fenton process is receiving popularity as a wastewater treatment technique that can be used for hazardous landfill leachate. The treatment is simple, yet involves complex interactions between the affecting parameters including reaction time, H₂O₂ [...] Read more.

As an advanced oxidative processes, the Fenton process is receiving popularity as a wastewater treatment technique that can be used for hazardous landfill leachate. The treatment is simple, yet involves complex interactions between the affecting parameters including reaction time, H₂O₂/Fe²⁺ ratio, pH, and iron (II) ion concentration. Hence, the purpose of this present study was to analyze the factors affecting landfill leachate treatment as well as their interaction by means of response surface methodology (RSM) with central composite design. The independent variables were reaction time, H₂O₂/Fe²⁺ ratio, iron (II) ion concentration, and pH, and the dependent variable (response) was color-removal percentage. The optimum treatment conditions for pH, H₂O₂/Fe²⁺ ratio, Fe²⁺ concentration, and reaction time were 8.36, 3.32, 964.95 mg/L, and 50.15 min, respectively. The model predicted 100% color removal in optimum conditions, which was close to that obtained from the experiment (97.68%). In conclusion, the optimized Fenton process using the RSM approach promotes efficient landfill leachate treatment that is even higher than that already reported. Full article

► Show Figures

Figure 1

16 pages, 740 KiB

Open AccessArticle

Optimization Based on Pattern Search Algorithm Applied to pH Non-Linear Control: Application to Alkalinization Process of Sugar Juice

by Jairo Palacio-Morales, Andrés Tobón and Jorge Herrera

Processes 2021, 9(12), 2283; https://doi.org/10.3390/pr9122283 - 20 Dec 2021

Cited by 6 | Viewed by 2091

Abstract

In this paper, an approach for the tuning of a model-based non-linear predictive control (NMPC) is presented. The proposed control uses the pattern search optimization algorithm (PSM), which is applied to the pH non-linear control in the alkalinization process of sugar juice. First, [...] Read more.

In this paper, an approach for the tuning of a model-based non-linear predictive control (NMPC) is presented. The proposed control uses the pattern search optimization algorithm (PSM), which is applied to the pH non-linear control in the alkalinization process of sugar juice. First, the model identification is made using the Takagi Sugeno T-S fuzzy inference systems with multidimensional fuzzy sets; the next step is the controller parameters tuning. The PSM algorithm is used in both cases. The proposed approach allows the minimization of model uncertainty and decreases, in the response, the error in a steady state when compared with other authors who perform the same procedure but apply other optimization algorithms. The results show an improvement in the steady-state error in the plant response. Full article

(This article belongs to the Section Advanced Digital and Other Processes)

► Show Figures

Figure 1

11 pages, 1147 KiB

Open AccessFeature PaperArticle

Oil Recovery from Dry Grind Ethanol Plant Coproducts Using Ethanol

by Md. Sanaul Huda and Nurun Nahar

Processes 2021, 9(12), 2282; https://doi.org/10.3390/pr9122282 - 20 Dec 2021

Cited by 1 | Viewed by 2310

Abstract

Corn ethanol bio-refineries are seeking economic processing strategies for recovering oil from their coproducts. The addition of ethanol can be an efficient method to recover the oil from the coproducts as the industry has available ethanol. This study considered the effects of ethanol [...] Read more.

Corn ethanol bio-refineries are seeking economic processing strategies for recovering oil from their coproducts. The addition of ethanol can be an efficient method to recover the oil from the coproducts as the industry has available ethanol. This study considered the effects of ethanol on oil recovery from distillers’ dried grains with solubles (DDGS) and oil partitioning from whole stillage (WS) on a laboratory scale. Ethanol was added with original and heavier fraction DDGS in different temperatures (room temperature ~20 °C, 30 °C, 40 °C, and 50 °C) and solids loadings (20%, 30%, and 40%), and their effects on oil recovery were evaluated. The whole stillage was incubated with ethanol at room temperature (~20 °C) and 50 °C separately to analyze WS’s oil distribution in the liquid and solid phases. The amount of recovered oil from the original and heavier fractions of DDGS varies from 25–45% and 45–70%, respectively, with an increment of temperature. Increasing solids loadings up to 30% had no effect on oil recovery from either DDGS sample. Ethanol treatment in WS resulted in 8–10% higher wet yield of liquid fraction and 17–20% of oil increase in liquid fraction than the control treatment. It is also notable that temperature positively impacted oil partitioning from WS. The results showed that ethanol could improve oil recovery from DDGS and oil partition in WS by varying different process conditions. This outcome is beneficial to ethanol plants to increase corn oil yield using their existing setup and in-situ product. Full article

► Show Figures

Figure 1

25 pages, 1820 KiB

Open AccessArticle

The Analysis of the Spatial Production Mechanism and the Coupling Coordination Degree of the Danwei Compound Based on the Spatial Ternary Dialectics

by Zihan Yang, Jianqiang Yang and Kai Ren

Processes 2021, 9(12), 2281; https://doi.org/10.3390/pr9122281 - 20 Dec 2021

Cited by 2 | Viewed by 2400

Abstract

With the gradual deepening of the development of high-quality urban transformation, the “Danwei Compound” urban space production method constitutes the basis of Chinese current urban spatial transformation. The transformation plan of the original danwei compound “stock” to promote the healthy development of urban [...] Read more.

With the gradual deepening of the development of high-quality urban transformation, the “Danwei Compound” urban space production method constitutes the basis of Chinese current urban spatial transformation. The transformation plan of the original danwei compound “stock” to promote the healthy development of urban society has become the focus of research. First, with the help of Lefebvre’s space production theory, combined with the spatial transformation characteristics of its own structural form experienced by the Chinese urban danwei compound, the space production is divided into three stages, namely, the diversity-orderly type average space of the danwei compound system period, dispersed type abstract space of the commercial enclosed community period, and the integrated differential space of a livable community undergoing regeneration and transformation. At each stage, the government, market, and residents have different influences on time-space production. Secondly, using Hefei’s typical danwei compound as the research carrier, according to the space ternary dialectics, a multi-level analysis of “representations of space-representational space-spatial practice” is carried out on the production mechanism, and the logic of different types of spaces in different periods are described. Among them, the representations of space of the change of the danwei compound are the interrelationship of multiple governance subjects in different periods, such as changes in the implementation degree of governance strategies, the degree of residents’ community governance participation, residents’ satisfaction with community governance, etc. The representational space is the residents’ community perception and interpersonal relationship at different transition stages, Interpersonal trust, and other social relations’ changes. Spatial practice is manifested in changes in the support of public service facilities, public space, per capita living area, building quality, architectural style, and illegal building area. Finally, the three-dimensional space dialectical coupling coordination degree model is used to analyze and compare the representations of space of typical settlements in the three stages and the coupling characteristics of the representational space and the practice of space. On this basis, we provide innovative ideas and put forward relevant measures and suggestions for the regeneration, transformation, and development of livable areas. Full article

(This article belongs to the Special Issue Process Control and Smart Manufacturing for Industry 4.0)

► Show Figures

Figure 1

10 pages, 5843 KiB

Open AccessArticle

Industrial Application of Mechanical Reduction on Continuous Casting of Bearing Steel Bloom

by Xinghua Chen, Wei Deng and Shuai Niu

Processes 2021, 9(12), 2280; https://doi.org/10.3390/pr9122280 - 20 Dec 2021

Cited by 3 | Viewed by 2822

Abstract

Industrial experiments of mechanical soft reduction in continuous casting were conducted in the present study aiming to improve the internal quality of the bearing steel blooms. Two methods were developed to verify the solidification model for a reliable crater end in the caster, [...] Read more.

Industrial experiments of mechanical soft reduction in continuous casting were conducted in the present study aiming to improve the internal quality of the bearing steel blooms. Two methods were developed to verify the solidification model for a reliable crater end in the caster, which is provided by SMS CONCAST. The verified solidification model was applied to determine the solidification status of the bloom and provides theoretical reduction region. Several trials were conducted to study the optimization of the reduction rate regarding the V-shaped and centerline segregation of the bloom. The results show an obvious improvement of internal quality in the bearing steel bloom by applying appropriate reduction during casting. Full article

(This article belongs to the Special Issue High-Efficiency and High-Quality Continuous Casting Processes)

► Show Figures

Figure 1

11 pages, 3681 KiB

Open AccessFeature PaperArticle

Catalytic Activity of Ni Nanotubes Covered with Nanostructured Gold

by Alena Shumskaya, Larissa Panina, Alexander Rogachev, Zhanna Ihnatovich, Artem Kozlovskiy, Maxim Zdorovets, Egor Kaniukov and Ilya Korolkov

Processes 2021, 9(12), 2279; https://doi.org/10.3390/pr9122279 - 20 Dec 2021

Cited by 1 | Viewed by 2139

Abstract

Ni nanotubes (NTs) were produced by the template method in the pores of ion-track membranes and then were successfully functionalized with gold nanoparticles (Ni@Au NTs) using electroless wet-chemical deposition with the aim to demonstrate their high catalytic activity. The fabricated NTs were characterized [...] Read more.

Ni nanotubes (NTs) were produced by the template method in the pores of ion-track membranes and then were successfully functionalized with gold nanoparticles (Ni@Au NTs) using electroless wet-chemical deposition with the aim to demonstrate their high catalytic activity. The fabricated NTs were characterized using a variety of techniques in order to determine their morphology and dimensions, crystalline structure, and magnetic properties. The morphology of Au coating depended on the concentration of gold chloride aqueous solution used for Au deposition. The catalytic activity was evaluated by a model reaction of the reduction of 4-nitrophenol by borohydride ions in the presence of Ni and Ni@Au NTs. The reaction was monitored spectrophotometrically in real time by detecting the decrease in the absorption peaks. It was found that gold coating with needle-like structure formed at a higher Au-ions concentration had the strongest catalytic effect, while bare Ni NTs had little effect. The presence of a magnetic core allowed the extraction of the catalyst with the help of a magnetic field for reusable applications. Full article

(This article belongs to the Special Issue Advances in Innovative Engineering Materials and Processes (II))

► Show Figures

Graphical abstract

12 pages, 1567 KiB

Open AccessFeature PaperArticle

CFD Modeling of Flame Jump across Air Gap between Evasé and Capture Duct for Ventilation Air Methane Abatement

by Zhengbiao Peng, Jafar Zanganeh and Behdad Moghtaderi

Processes 2021, 9(12), 2278; https://doi.org/10.3390/pr9122278 - 19 Dec 2021

Cited by 2 | Viewed by 2237

Abstract

The ventilation air–methane (VAM) released from underground mines is often transported into regenerative thermal oxidizer (RTO) devices and burnt into heat energy. This study numerically investigates the scenarios where explosion occurs inside the RTO and the flame and pressure waves propagate back quickly [...] Read more.

The ventilation air–methane (VAM) released from underground mines is often transported into regenerative thermal oxidizer (RTO) devices and burnt into heat energy. This study numerically investigates the scenarios where explosion occurs inside the RTO and the flame and pressure waves propagate back quickly towards the VAM discharge duct. Possibilities of secondary explosion in the discharge duct, hence in the downstream underground mines, are examined. The results critically showed that when the methane concentration accumulated in the RTO reached 7.5% or above, the flame generated from the explosion jumped to the evasé of the discharge section (over a distance of 29.4 m) and could induce explosions in underground mines. Full article

(This article belongs to the Special Issue Advancement in Computational Fluid Mechanics and Optimization Methods)

► Show Figures

Figure 1

15 pages, 2006 KiB

Open AccessArticle

Quality of Milled Rice from Large-Scale Dried Paddy Rice by Hot Air Combined with Radio Frequency Heating

by Karn Chitsuthipakorn and Sa-nguansak Thanapornpoonpong

Processes 2021, 9(12), 2277; https://doi.org/10.3390/pr9122277 - 19 Dec 2021

Cited by 4 | Viewed by 3446

Abstract

A scaled-up process for paddy drying was developed using hot air (HA) combined with radio frequency (RF) heating. The study was conducted using hot air (control treatment) arranged in descending order in four temperature levels, namely 80 °C at moisture content of 25–26%, [...] Read more.

A scaled-up process for paddy drying was developed using hot air (HA) combined with radio frequency (RF) heating. The study was conducted using hot air (control treatment) arranged in descending order in four temperature levels, namely 80 °C at moisture content of 25–26%, 70 °C at moisture content of 20–25%, 60 °C at moisture content of 17–20%, and 50 °C at moisture content of 13–17%, as well as with hot air combined with radio frequency (HA/RF) at different paddy temperatures (45–60 °C) by adjusting the appropriate RF energy when passing through RF heating chamber, namely HA/RF45, HA/RF50, HA/RF55, and HA/RF60. Each treatment was performed in three replicates and data were statistically analyzed in a randomized complete block design. The quality attributes of paddies affected by the drying process were assessed: fissure percentage, color, milling quality, and sensory evaluation. The drying efficiency showed that the drying time and the specific energy consumption could be decreased by up to 54.44% and 23.17% at HA/RF60 and HA/RF45, respectively. As the RF heating temperature increased, the fissure percentage of brown rice kernels at HA/RF45 and HA was not significantly impacted. Regarding color evaluation, combining RF heating and convective drying at all given conditions could be statistically applied in terms of the b*, WI, and ΔE* value. Considering the milling yield of HA as the baseline, head rice yield was maximized at HA/RF45, while bran yield reached the maximum at HA/RF60. The liking score of cooked rice after it was dried using the HA method was the highest. This study concludes that the HA/RF45 was the most appropriate drying condition, and this may provide preliminary exposure to the industrial drying of paddies. Full article

(This article belongs to the Topic Innovative Food Processing Technologies)

► Show Figures

Figure 1

28 pages, 3401 KiB

Open AccessArticle

Migration-Based Moth-Flame Optimization Algorithm

by Mohammad H. Nadimi-Shahraki, Ali Fatahi, Hoda Zamani, Seyedali Mirjalili, Laith Abualigah and Mohamed Abd Elaziz

Processes 2021, 9(12), 2276; https://doi.org/10.3390/pr9122276 - 18 Dec 2021

Cited by 55 | Viewed by 4127

Abstract

Moth–flame optimization (MFO) is a prominent swarm intelligence algorithm that demonstrates sufficient efficiency in tackling various optimization tasks. However, MFO cannot provide competitive results for complex optimization problems. The algorithm sinks into the local optimum due to the rapid dropping of population diversity [...] Read more.

Moth–flame optimization (MFO) is a prominent swarm intelligence algorithm that demonstrates sufficient efficiency in tackling various optimization tasks. However, MFO cannot provide competitive results for complex optimization problems. The algorithm sinks into the local optimum due to the rapid dropping of population diversity and poor exploration. Hence, in this article, a migration-based moth–flame optimization (M-MFO) algorithm is proposed to address the mentioned issues. In M-MFO, the main focus is on improving the position of unlucky moths by migrating them stochastically in the early iterations using a random migration (RM) operator, maintaining the solution diversification by storing new qualified solutions separately in a guiding archive, and, finally, exploiting around the positions saved in the guiding archive using a guided migration (GM) operator. The dimensionally aware switch between these two operators guarantees the convergence of the population toward the promising zones. The proposed M-MFO was evaluated on the CEC 2018 benchmark suite on dimension 30 and compared against seven well-known variants of MFO, including LMFO, WCMFO, CMFO, CLSGMFO, LGCMFO, SMFO, and ODSFMFO. Then, the top four latest high-performing variants were considered for the main experiments with different dimensions, 30, 50, and 100. The experimental evaluations proved that the M-MFO provides sufficient exploration ability and population diversity maintenance by employing migration strategy and guiding archive. In addition, the statistical results analyzed by the Friedman test proved that the M-MFO demonstrates competitive performance compared to the contender algorithms used in the experiments. Full article

(This article belongs to the Special Issue Evolutionary Process for Engineering Optimization)

► Show Figures

Figure 1

15 pages, 988 KiB

Open AccessArticle

Study of Static and Dynamic Behavior of a Membrane Reactor for Hydrogen Production

by Rubayyi T. Alqahtani, Abdelhamid Ajbar, Samir Kumar Bhowmik and Rabab Ali Alghamdi

Processes 2021, 9(12), 2275; https://doi.org/10.3390/pr9122275 - 18 Dec 2021

Cited by 3 | Viewed by 2017

Abstract

The paper investigates the stability and bifurcation phenomena that can occur in membrane reactors for the production of hydrogen by ammonia decomposition. A simplified mixed model of the membrane reactor is studied and two expressions of hydrogen permeation are investigated. The effect of [...] Read more.

The paper investigates the stability and bifurcation phenomena that can occur in membrane reactors for the production of hydrogen by ammonia decomposition. A simplified mixed model of the membrane reactor is studied and two expressions of hydrogen permeation are investigated. The effect of the model design and operating parameters on the existence of steady state multiplicity is discussed. In this regard, it is shown that the adsorption-inhibition effect caused by the competitive adsorption of ammonia can lead to the occurrence of multiple steady states in the model. The steady state multiplicity exists for a wide range of feed ammonia concentration and reactor residence time. The effect of the adsorption constant, the membrane surface area and its permeability on the steady state multiplicity is delineated. The analysis also shows that no Hopf bifurcation can occur in the studied model. Full article

(This article belongs to the Special Issue Industrial Chemistry Reaction: Kinetics, Mass Transfer and Industrial Reactor Design (II))

► Show Figures

Figure 1

8 pages, 1612 KiB

Open AccessArticle

Solubility and Activation of Hydrogen in the Non-Catalytic Upgrading of Venezuela Orinoco, China Liaohe, and China Fengcheng Atmospheric Residues

by Shunfeng Ji and Anran Zeng

Processes 2021, 9(12), 2274; https://doi.org/10.3390/pr9122274 - 17 Dec 2021

Cited by 1 | Viewed by 1742

Abstract

The solubility of hydrogen in the Venezuela Orinoco, China Liaohe, and China Fengcheng atmospheric residues under reaction conditions of 400 °C, 4 MPa for 20 min was analyzed by determining the composition and structure changes of the products. Activation of hydrogen during the [...] Read more.

The solubility of hydrogen in the Venezuela Orinoco, China Liaohe, and China Fengcheng atmospheric residues under reaction conditions of 400 °C, 4 MPa for 20 min was analyzed by determining the composition and structure changes of the products. Activation of hydrogen during the upgrading process was also determined and discussed by the probe method. The results show that lighter components produced in the reaction can increase the hydrogen solubility as the reaction proceeds, and the lighter components present at the liquid level have positive effects on the transfer of hydrogen from the gas phase to the liquid phase. Naphthenic aromatic structures, sulphur and metals have a positive effect on hydrogen activation in the trend of naphthenic aromatic structures > sulphur > metals. Moreover, when sulphur is present, nickel tetraphenylporphyrin has a better effect on hydrogen activation than Vanadium tetraphenylporphyrin. During upgrading, the Venezuela Orinoco atmospheric residue with more sulphur, metals and naphthenic aromatic structures can activate more hydrogen. Both the hydrogen solubility and residue composition have significant effect on the upgrading process. Full article

(This article belongs to the Special Issue Heavy Oil Chemistry and Processing Technology)

► Show Figures

Figure 1

19 pages, 2870 KiB

Open AccessArticle

Research on Measurement and Application of China’s Regional Logistics Development Level under Low Carbon Environment

by Zixue Guo, Yu Tian, Xinmei Guo and Zefang He

Processes 2021, 9(12), 2273; https://doi.org/10.3390/pr9122273 - 17 Dec 2021

Cited by 3 | Viewed by 2182

Abstract

To solve the problem of fuzziness and randomness in regional logistics decarbonization evaluation and accurately assess regional logistics decarbonization development, an evaluation model of regional logistics decarbonization development is established. First, the evaluation index of regional logistics decarbonization development is constructed from three [...] Read more.

To solve the problem of fuzziness and randomness in regional logistics decarbonization evaluation and accurately assess regional logistics decarbonization development, an evaluation model of regional logistics decarbonization development is established. First, the evaluation index of regional logistics decarbonization development is constructed from three dimensions: low-carbon logistics environment support, low-carbon logistics strength and low-carbon logistics potential. Second, the evaluation indexes are used as cloud model variables, and the cloud numerical characteristic values and cloud affiliation degrees are determined according to the cloud model theory. The entropy weight method is used to determine the index weights, and the comprehensive determination degree of the research object affiliated to the logistics decarbonization level is calculated comprehensively. Finally, Beijing-Tianjin-Hebei region is used as an example for empirical evidence, analyzing the development logistics decarbonization and its and temporal variability in Beijing, Tianjin and Hebei provinces and cities. The results of the study show that the development logistics decarbonization in Beijing, Tianjin and Hebei Province has been improved to different degrees during 2013–2019, but the development is uneven. Developing to 2019, the three provinces and cities of Beijing, Tianjin and Hebei still have significant differences in terms of economic environment, logistics industry scale, logistics industry inputs and outputs, and technical support. Full article

(This article belongs to the Special Issue Expanding the Horizons of Manufacturing: Towards Wide Integration, Smart Systems and Tools)

► Show Figures

Figure 1

17 pages, 9078 KiB

Open AccessArticle

Infection Units: A Novel Approach for Modeling COVID-19 Spread

by Jose C. Merchuk, Francisco García-Camacho and Lorenzo López-Rosales

Processes 2021, 9(12), 2272; https://doi.org/10.3390/pr9122272 - 17 Dec 2021

Cited by 1 | Viewed by 2206

Abstract

A novel mechanistic model of COVID-19 spread is presented. The pool of infected individuals is not homogeneously mixed but is viewed as a passage into which individuals enter upon the contagion, through which they pass (in the manner of “plug flow”) and exit [...] Read more.

A novel mechanistic model of COVID-19 spread is presented. The pool of infected individuals is not homogeneously mixed but is viewed as a passage into which individuals enter upon the contagion, through which they pass (in the manner of “plug flow”) and exit at their recovery points within a fixed time. Our novel concept of infection unit is defined. The model separately considers various population pools: two of symptomatic and asymptomatic infected patients; three different pools of recovered individuals; of assisted hospitalized patients; of the quarantined; and of those who die from COVID-19. Transmission of this disease is described by an infection rate function, modulated by an encounter frequency function. This definition makes redundant the addition of a separate pool for the exposed, as done in several other models. Simulations are presented. The effects of social restrictions and of quarantine policies on pandemic spread are demonstrated. The model differs conceptually from others of the kind in the description of the transmission dynamics of the disease. A set of experimental data is used to calibrate our model, which predicts the dynamic behavior of each of the defined pools during pandemic spread. Full article

(This article belongs to the Special Issue Mathematical Modeling and Numerical Research of Heat Transfer in Heterogeneous Flows)

► Show Figures

Figure 1

15 pages, 3599 KiB

Open AccessArticle

Ginsenosides Conversion and Anti-Oxidant Activities in Puffed Cultured Roots of Mountain Ginseng

by Jian Yu Pu, Zelika Mega Ramadhania, Ramya Mathiyalagan, Yue Huo, Yaxi Han, Jin Feng Li, Jong Chan Ahn, Feng Jiao Xu, Dong Wook Lee, Xu Hui Zeng, Deok Chun Yang, Gi-Young Kwak and Se Chan Kang

Processes 2021, 9(12), 2271; https://doi.org/10.3390/pr9122271 - 17 Dec 2021

Cited by 4 | Viewed by 2456

Abstract

CRMG (Cultured Roots of Mountain Ginseng) have the advantages in scale-up production, safety, and pharmacological efficacies. Though several methods are available for the conversion of major to minor ginsenosides, which has more pharmacological activities, a single step process with high temperature and pressure [...] Read more.

CRMG (Cultured Roots of Mountain Ginseng) have the advantages in scale-up production, safety, and pharmacological efficacies. Though several methods are available for the conversion of major to minor ginsenosides, which has more pharmacological activities, a single step process with high temperature and pressure as a puffing method took place in this study to gain and produce more pharmacologically active compounds. Puffed CRMG exhibited an acceleration of major ginsenosides to minor ginsenosides conversions, and released more phenolic and flavonoid compounds. HPLC analysis was used to detect a steep decrease in the contents of major ginsenosides (Re, Rf, Rg1, Rg2, Rb1, Rb2, Rb3, Rc and Rd) with increasing pressure; on the contrary, the minor ginsenosides (20 (S, R)-Rg3, Rg5, Rk1, Rh1, Rh2, Rg6, F4 and Rk3) contents increased. Minor ginsenosides, such as Rg6, F4 and Rk3, were firstly reported to be produced from puffed CRMG. After the puffing process, phenolics, flavonoids, and minor ginsenoside contents were increased, and also, the antioxidant properties, such as DPPH inhibition and reducing the power of puffed CRMG, were significantly enhanced. Puffed CRMG at 490.3 kPa and 588.4 kPa had a low toxicity on HaCaT (immortalized human epidermal keratinocyte) cells at 200 μg/mL, and could significantly reduce ROS by an average of 60%, compared to the group treated with H₂O₂. Therefore, single step puffing of CRMG has the potential to be utilized for functional food and cosmeceuticals. Full article

(This article belongs to the Topic Innovative Food Processing Technologies)

► Show Figures

Graphical abstract

22 pages, 2575 KiB

Open AccessFeature PaperArticle

Design of a Bench-Scale Tubular Reactor Similar to Plug Flow Reactor for Gas-Phase Kinetic Data Generation-Illustration with the Pyrolysis of Octanoic Acid

by Julien Gornay, Edouard Plasari, Jean-François Portha, Pierre-Alexandre Glaude, Francis Billaud and Lucie Coniglio

Processes 2021, 9(12), 2270; https://doi.org/10.3390/pr9122270 - 17 Dec 2021

Viewed by 2392

Abstract

The material described in this article deals with waste conversion into energy vectors by pyrolysis, steam cracking, or oxidation of liquid biomass, carried out at small to medium scale. The design of a bench-scale experimental setup devoted to gas phase kinetic data generation [...] Read more.

The material described in this article deals with waste conversion into energy vectors by pyrolysis, steam cracking, or oxidation of liquid biomass, carried out at small to medium scale. The design of a bench-scale experimental setup devoted to gas phase kinetic data generation in a tubular reactor under laminar regime close to plug flow is detailed based on a very simple approach. Validation of the designed bench-scale setup was successfully carried out within the context of octanoic acid pyrolysis by generating kinetic data with satisfactory measurement repeatability and material balances. The key to this positive result is that axial dispersion coefficient is much smaller in gas-phase than in liquid-phase, thus allowing the designed small sized tubular reactor to be close to the plug flow reactor. Such a feature of the axial dispersion coefficient is not well known by the wider public. Besides, octanoic acid was selected as surrogate for carboxylic acids because of their key role in various industrial applications (combustion of ethyl biodiesel; production of biofuel and biosourced chemicals). Full article

(This article belongs to the Section Process Control and Monitoring)

► Show Figures

Figure 1

10 pages, 1731 KiB

Open AccessArticle

Valorization of Waste Lignocellulose to Furfural by Sulfonated Biobased Heterogeneous Catalyst Using Ultrasonic-Treated Chestnut Shell Waste as Carrier

by Jianguang Liang, Jingjian Zha, Nana Zhao, Zhengyu Tang, Yucai He and Cuiluan Ma

Processes 2021, 9(12), 2269; https://doi.org/10.3390/pr9122269 - 17 Dec 2021

Cited by 10 | Viewed by 2191

Abstract

Recently, the highly efficient production of value-added biobased chemicals from available, inexpensive, and renewable biomass has gained more and more attention in a sustainable catalytic process. Furfural is a versatile biobased chemical, which has been widely used for making solvents, lubricants, inks, adhesives, [...] Read more.

Recently, the highly efficient production of value-added biobased chemicals from available, inexpensive, and renewable biomass has gained more and more attention in a sustainable catalytic process. Furfural is a versatile biobased chemical, which has been widely used for making solvents, lubricants, inks, adhesives, antacids, polymers, plastics, fuels, fragrances, flavors, fungicides, fertilizers, nematicides, agrochemicals, and pharmaceuticals. In this work, ultrasonic-treated chestnut shell waste (UTS-CSW) was utilized as biobased support to prepare biomass-based heterogeneous catalyst (CSUTS-CSW) for transforming waste lignocellulosic materials into furfural. The pore and surface properties of CSUTS-CSW were characterized with BET, SEM, XRD, and FT-IR. In toluene–water (2:1, v:v; pH 1.0), CSUTS-CSW (3.6 wt%) converted corncob into furfural yield in the yield of 68.7% at 180 °C in 15 min. CSUTS-CSW had high activity and thermostability, which could be recycled and reused for seven batches. From first to seventh, the yields were obtained from 68.7 to 47.5%. Clearly, this biobased solid acid CSUTS-CSW could be used for the sustainable conversion of waste biomasses into furfural, which had potential application in future. Full article

(This article belongs to the Special Issue Progress in Biorefinery of Lignocellulosic Biomass to Bio-Energies and Bio-Based Chemicals)

► Show Figures

Figure 1

14 pages, 4405 KiB

Open AccessArticle

Continuous Crystallization Using Ultrasound Assisted Nucleation, Cubic Cooling Profiles and Oscillatory Flow

by Arne Vancleef, Ward De Beuckeleer, Tom Van Gerven, Leen C. J. Thomassen and Leen Braeken

Processes 2021, 9(12), 2268; https://doi.org/10.3390/pr9122268 - 17 Dec 2021

Cited by 2 | Viewed by 2945

Abstract

Continuous tubular crystallizers have the potential to reduce manufacturing costs and increase product quality. However, designing tubular crystallizers is a complex and challenging task as crystallization is a complex, multiphase process with a propensity for fouling and clogging. While several designs have been [...] Read more.

Continuous tubular crystallizers have the potential to reduce manufacturing costs and increase product quality. However, designing tubular crystallizers is a complex and challenging task as crystallization is a complex, multiphase process with a propensity for fouling and clogging. While several designs have been proposed to overcome these issues, these designs are either unproven or poorly scalable and complex. In this work a continuous crystallizer is designed and evaluated to mitigate these issues. The tubular crystallizer combines a novel method to obtain a cubic cooling profile to control the supersaturation, ultrasound to induce nucleation and oscillatory flow to improve mixing and minimize fouling and sedimentation. The results show that the crystallizer was able to operate for more than 4 h without clogging, with high yields and a narrow particle size distribution. The design proposed here is therefore considered a viable approach for continuous crystallizers. Full article

(This article belongs to the Special Issue Continuous Crystallization Processes and Product Design)

► Show Figures

Figure 1

17 pages, 10699 KiB

Open AccessFeature PaperArticle

Analysis of Rotor Position Detection Performance According to the Frequency of Square Waveform Voltage in the Harmonic Injection Sensorless Method through HILS

by Kyeong-Rok Moon and Dong-Myung Lee

Processes 2021, 9(12), 2267; https://doi.org/10.3390/pr9122267 - 16 Dec 2021

Cited by 1 | Viewed by 1771

Abstract

In this paper, the rotor position estimation performance of the sensorless scheme for permanent magnet synchronous motors (PMSMs) implemented through the injection of high-frequency square-wave voltage according to the frequency of the square-wave voltage is presented through HILS (Hardware In the Loop Simulation) [...] Read more.

In this paper, the rotor position estimation performance of the sensorless scheme for permanent magnet synchronous motors (PMSMs) implemented through the injection of high-frequency square-wave voltage according to the frequency of the square-wave voltage is presented through HILS (Hardware In the Loop Simulation) experiments. An inverter using an IGBT device usually has a switching frequency of around 15 kHz. On the other hand, GaN devices that can be switched on and off at frequencies higher than 100 kHz have been recently developed, and research is being actively conducted to apply GaNs to a variable speed system. The purpose of this study is to conduct HILS experiments to analysis the rotor position estimation ability of the sensorless technique in cases where a high switching frequency was applied, such as GaN devices, with that of a system having a usual switching frequency, such as IGBT. In the HILS system used in this study, an inverter and motor model implemented with Simulink are located in a real-time simulator. A sensorless motor control method was implemented with an FPGA control board, which includes a PWM interrupt service routine of 100 kHz frequency and a harmonic injection and position detection algorithm. The HILS experiments show rotor position detection errors according to the various frequency of the harmonic voltage injected for estimating the rotor position with a PWM frequency of 100 kHz cases. According to the experimental results, good position estimation was possible not only when the harmonic of 10 kHz corresponding to 1/10 of the PWM frequency was injected, but also when the harmonic of 1 kHz corresponding to 1/100 of the PWM frequency was injected. The experiments suggest that position estimation errors decrease as the frequency of the harmonic voltage increases, and, based on the foregoing, it is thought that the application of a GaN device capable of realizing a high switching frequency in a variable speed drive system can be another advantage. Full article

(This article belongs to the Special Issue Design, Concepts and Applications of Electric Machines)

► Show Figures

Figure 1

13 pages, 3070 KiB

Open AccessArticle

Slurry-Phase Carbonation Reaction Characteristics of AOD Stainless Steel Slag

by Meng-Jie Tao, Ya-Jun Wang, Jun-Guo Li, Ya-Nan Zeng, Shao-Hua Liu and Song Qin

Processes 2021, 9(12), 2266; https://doi.org/10.3390/pr9122266 - 16 Dec 2021

Cited by 8 | Viewed by 2184

Abstract

Argon oxygen decarburization stainless steel slag (AOD slag) has high mineral carbonation activity. AOD slag carbonation has both the resource utilization of metallurgical waste slag and the carbon reduction effect of CO₂ storage. This paper aimed to study carbonation reaction characteristics of [...] Read more.

Argon oxygen decarburization stainless steel slag (AOD slag) has high mineral carbonation activity. AOD slag carbonation has both the resource utilization of metallurgical waste slag and the carbon reduction effect of CO₂ storage. This paper aimed to study carbonation reaction characteristics of AOD slag. Under the slurry-phase accelerated carbonation route, the effect of stirring speed (r) and reaction temperature (T) on AOD slag’s carbonation was studied by controlling the reaction conditions. Mineral composition analysis and microscopic morphology analysis were used to explore the mineral phase evolution of AOD slag during the carbonation process. Based on the unreacted core model, the kinetic model of the carbonation reaction of AOD slag was analyzed. The results showed that the carbonation ratio of AOD slag reached its maximum value of 66.7% under the reaction conditions of a liquid to solid ratio (L/S) of 8:1, a CO₂ partial pressure of 0.2 MPa, a stirring speed of 450 r·min⁻¹, and a reaction temperature of 80 °C. The carbonation reaction of AOD slag was controlled by internal diffusion, and the calculated apparent activation energy was 22.28 kJ/mol. Full article

(This article belongs to the Special Issue Biochemical Processes for Sustainability)

► Show Figures

Graphical abstract

17 pages, 6840 KiB

Open AccessArticle

Hybrid Sleep Stage Classification for Clinical Practices across Different Polysomnography Systems Using Frontal EEG

by Cheng-Hua Su, Li-Wei Ko, Jia-Chi Juang and Chung-Yao Hsu

Processes 2021, 9(12), 2265; https://doi.org/10.3390/pr9122265 - 16 Dec 2021

Cited by 2 | Viewed by 2347

Abstract

Automatic bio-signal processing and scoring have been a popular topic in recent years. This includes sleep stage classification, which is time-consuming when carried out by hand. Multiple sleep stage classification has been proposed in recent years. While effective, most of these processes are [...] Read more.

Automatic bio-signal processing and scoring have been a popular topic in recent years. This includes sleep stage classification, which is time-consuming when carried out by hand. Multiple sleep stage classification has been proposed in recent years. While effective, most of these processes are trained and validated against a singular set of data in uniformed pre-processing, whilst in a clinical environment, polysomnography (PSG) may come from different PSG systems that use different signal processing methods. In this study, we present a generalized sleep stage classification method that uses power spectra and entropy. To test its generality, we first trained our system using a uniform dataset and then validated it against another dataset with PSGs from different PSG systems. We found that the system achieved an accuracy of 0.80 and that it is highly consistent across most PSG records. A few samples of NREM3 sleep were classified poorly, and further inspection showed that these samples lost crucial NREM3 features due to aggressive filtering. This implies that the system’s effectiveness can be evaluated by human knowledge. Overall, our classification system shows consistent performance against PSG records that have been collected from different PSG systems, which gives it high potential in a clinical environment. Full article

(This article belongs to the Special Issue Application of Artificial Intelligence in Industry and Medicine)

► Show Figures

Figure 1

12 pages, 1689 KiB

Open AccessFeature PaperArticle

Innovative Gold/Cobalt Ferrite Nanocomposite: Physicochemical and Cytotoxicity Properties

by Anna Motorzhina, Sonja Jovanović, Victor K. Belyaev, Dmitry Murzin, Stanislav Pshenichnikov, Valeria G. Kolesnikova, Alexander S. Omelyanchik, Lea Gazvoda, Matjaž Spreitzer, Larissa Panina, Valeria Rodionova, Marija Vukomanović and Kateryna Levada

Processes 2021, 9(12), 2264; https://doi.org/10.3390/pr9122264 - 16 Dec 2021

Cited by 4 | Viewed by 2723

Abstract

The combination of plasmonic material and magnetic metal oxide nanoparticles is widely used in multifunctional nanosystems. Here we propose a method for the fabrication of a gold/cobalt ferrite nanocomposite for biomedical applications. The composite includes gold cores of ~10 nm in diameter coated [...] Read more.

The combination of plasmonic material and magnetic metal oxide nanoparticles is widely used in multifunctional nanosystems. Here we propose a method for the fabrication of a gold/cobalt ferrite nanocomposite for biomedical applications. The composite includes gold cores of ~10 nm in diameter coated with arginine, which are surrounded by small cobalt ferrite nanoparticles with diameters of ~5 nm covered with dihydrocaffeic acid. The structure and elemental composition, morphology and dimensions, magnetic and optical properties, and biocompatibility of new nanocomposite were studied. The magnetic properties of the composite are mostly determined by the superparamagnetic state of cobalt ferrite nanoparticles, and optical properties are influenced by the localized plasmon resonance in gold nanoparticles. The cytotoxicity of gold/cobalt ferrite nanocomposite was tested using T-lymphoblastic leukemia and peripheral blood mononuclear cells. Studied composite has selective citotoxic effect on cancerous cells while it has no cytotoxic effect on healtly cells. The results suggest that this material can be explored in the future for combined photothermal treatment and magnetic theranostic. Full article

(This article belongs to the Special Issue Advances in Innovative Engineering Materials and Processes (II))

► Show Figures

Figure 1

14 pages, 3635 KiB

Open AccessFeature PaperArticle

Investigation of Individual Cells Replacement Concept in Lithium-Ion Battery Packs with Analysis on Economic Feasibility and Pack Design Requirements

by Manh-Kien Tran, Carlo Cunanan, Satyam Panchal, Roydon Fraser and Michael Fowler

Processes 2021, 9(12), 2263; https://doi.org/10.3390/pr9122263 - 16 Dec 2021

Cited by 69 | Viewed by 4186

Abstract

The optimization of lithium-ion (Li-ion) battery pack usage has become essential due to the increasing demand for Li-ion batteries. Since degradation in Li-ion batteries is inevitable, there has been some effort recently on research to maximize the utilization of Li-ion battery cells in [...] Read more.

The optimization of lithium-ion (Li-ion) battery pack usage has become essential due to the increasing demand for Li-ion batteries. Since degradation in Li-ion batteries is inevitable, there has been some effort recently on research to maximize the utilization of Li-ion battery cells in the pack. Some promising concepts include reconfigurable battery packs and cell replacement to limit the negative impact of early-degraded cells on the entire pack. This paper used a simulation framework, based on a cell voltage model and a degradation model, to study the feasibility and benefits of the cell replacement concept. The simulation conducted in MATLAB involves generating and varying Li-ion cells in the packs stochastically and simulating the life of the cells as well as the packs until they reach their end-of-life stage. It was found that the cell replacement method can increase the total number of cycles of the battery packs, effectively prolonging the lifespan of the packs. It is also determined that this approach can be more economically beneficial than the current approach of simple pack replacement. For the cell replacement concept to be practical, two main design criteria should be satisfied including individual cell monitoring and easy accessibility to cells at failure stage. Full article

(This article belongs to the Section Energy Systems)

► Show Figures

Figure 1

18 pages, 14360 KiB

Open AccessArticle

Evaluation of Landsat 8-like Land Surface Temperature by Fusing Landsat 8 and MODIS Land Surface Temperature Product

by Shenglin Li, Jinglei Wang, Dacheng Li, Zhongxin Ran and Bo Yang

Processes 2021, 9(12), 2262; https://doi.org/10.3390/pr9122262 - 15 Dec 2021

Cited by 12 | Viewed by 3047

Abstract

High-spatiotemporal-resolution land surface temperature (LST) is a crucial parameter in various environmental monitoring. However, due to the limitation of sensor trade-off between the spatial and temporal resolutions, such data are still unavailable. Therefore, the generation and verification of such data are of great [...] Read more.

High-spatiotemporal-resolution land surface temperature (LST) is a crucial parameter in various environmental monitoring. However, due to the limitation of sensor trade-off between the spatial and temporal resolutions, such data are still unavailable. Therefore, the generation and verification of such data are of great value. The spatiotemporal fusion algorithm, which can be used to improve the spatiotemporal resolution, is widely used in Landsat and MODIS data to generate Landsat-like images, but there is less exploration of combining long-time series MODIS LST and Landsat 8 LST product to generate Landsat 8-like LST. The purpose of this study is to evaluate the accuracy of the long-time series Landsat 8 LST product and the Landsat 8-like LST generated by spatiotemporal fusion. In this study, based on the Landsat 8 LST product and MODIS LST product, Landsat 8-like LST is generated using Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), Enhanced STARFM (ESTARFM), and the Flexible Spatiotemporal DAta Fusion (FSDAF) algorithm, and tested and verified in the research area located in Gansu Province, China. In this process, Landsat 8 LST product was verified based on ground measurements, and the fusion results were comprehensively evaluated based on ground measurements and actual Landsat 8 LST images. Ground measurements verification indicated that Landsat 8 LST product was highly consistent with ground measurements. The Root Mean Square Error (RMSE) was 2.862 K, and the coefficient of determination R² was 0.952 at All stations. Good fusion results can be obtained for the three spatiotemporal algorithms, and the ground measurements verified at All stations show that R² was more significant than 0.911. ESTARFM had the best fusion result (R² = 0.915, RMSE = 3.661 K), which was better than STARFM (R² = 0.911, RMSE = 3.746 K) and FSDAF (R² = 0.912, RMSE = 3.786 K). Based on the actual Landsat 8 LST images verification, the fusion images were highly consistent with actual Landsat 8 LST images. The average RMSE of fusion images about STARFM, ESTARFM, and FSDAF were 2.608 K, 2.245 K, and 2.565 K, respectively, and ESTARFM is better than STARFM and FSDAF in most cases. Combining the above verification, the fusion results of the three algorithms were reliable and ESTARFM had the highest fusion accuracy. Full article

(This article belongs to the Special Issue Innovation in Chemical Plant Design)

► Show Figures

Figure 1

15 pages, 10959 KiB

Open AccessArticle

Pressure Fluctuation Characteristics of High-Speed Centrifugal Pump with Enlarged Flow Design

by Jianyi Zhang, Hao Yang, Haibing Liu, Liang Xu and Yuwei Lv

Processes 2021, 9(12), 2261; https://doi.org/10.3390/pr9122261 - 15 Dec 2021

Cited by 7 | Viewed by 2783

Abstract

The pressure fluctuations of high-speed centrifugal pumps are the hotspot in pump research. Pressure fluctuations is differ for different structural designs and flow structures. High-speed centrifugal pumps are usually designed to increase efficiency with an enlarged flow design at a low specific speed, [...] Read more.

The pressure fluctuations of high-speed centrifugal pumps are the hotspot in pump research. Pressure fluctuations is differ for different structural designs and flow structures. High-speed centrifugal pumps are usually designed to increase efficiency with an enlarged flow design at a low specific speed, which changes the structure of the pump. In order to analyze the pressure fluctuations of a high-speed centrifugal pump with an enlarged flow design, the pressure was measured, and the flow field of the pump was simulated with different flow rates. Through analysis, we found that pressure fluctuations varied periodically and was consistent with the blade frequency. The pressure fluctuations at the guide vane and the interference region were also closely related to the vortices at the impeller outlet, which changed differently at different flow rates. The results showed that the high-speed centrifugal pump with an enlarged design had better performance at a large flow rate. The results in this paper can provide reference for the design of a pump that should be designed with the enlarged flow method. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

► Show Figures

Figure 1

16 pages, 2473 KiB

Open AccessArticle

Analysis of Dynamic Characteristics for Machine Tools Based on Dynamic Stiffness Sensitivity

by Chunhui Li, Zhiqiang Song, Xianghua Huang, Hui Zhao, Xuchu Jiang and Xinyong Mao

Processes 2021, 9(12), 2260; https://doi.org/10.3390/pr9122260 - 15 Dec 2021

Cited by 4 | Viewed by 2915

Abstract

Dynamic parameters are the intermediate information of the entirety of machine dynamics. The differences between components have not been combined with the structural vibration in the cutting process, so it is difficult to directly represent the dynamic characteristics of the whole machine related [...] Read more.

Dynamic parameters are the intermediate information of the entirety of machine dynamics. The differences between components have not been combined with the structural vibration in the cutting process, so it is difficult to directly represent the dynamic characteristics of the whole machine related to spatial position. This paper presents a method to identify sensitive parts according to the dynamic stiffness-sensitivity algorithm, which represents the dynamic characteristics of the whole machine tool. In this study, two experiments were carried out, the simulation verification experiment (dynamic experiment with variable stiffness) and modal analysis experiment (vibration test of five-axis gantry milling machine). The key modes of sensitive parts obtained by this method can represent the position-related dynamic characteristics of the whole machine. The characteristic obtained is that the inherent properties of machine-tool structure are independent of excitation. The method proposed in this paper can accurately represent the dynamic characteristics of the whole machine tool. Full article

(This article belongs to the Special Issue Numerical Simulation of Nonlinear Dynamical Systems)

► Show Figures

Figure 1

17 pages, 4316 KiB

Open AccessArticle

Macroscopic Behavior and Microscopic Structure Evolution of Marine Clay in One-Dimensional Compression Revealed by Discrete Element Simulation

by Lisha Luo, Zhifu Shen, Hongmei Gao, Zhihua Wang and Xin Zhou

Processes 2021, 9(12), 2259; https://doi.org/10.3390/pr9122259 - 14 Dec 2021

Cited by 2 | Viewed by 1925

Abstract

Marine clay has been attracting in-depth research on its mechanical behavior and internal structure evolution, which are crucial to marine infrastructure safety. In the formation process of marine clay, including the sedimentation and consolidation stages, the compression behavior and internal structure evolution are [...] Read more.

Marine clay has been attracting in-depth research on its mechanical behavior and internal structure evolution, which are crucial to marine infrastructure safety. In the formation process of marine clay, including the sedimentation and consolidation stages, the compression behavior and internal structure evolution are highly dependent on the pore water salinity. Discrete element method (DEM) simulation is a powerful tool to study the microscopic mechanics behind the complicated macroscopic mechanical behavior of marine clay. In this study, a DEM simulation scheme is systematically proposed to numerically study the macroscopic beahvior and microscopic structure evolution of marine clay in one-dimensional compression that mimics the marine clay formation process. First, the proposed calculation scheme for double layer repulsive interaction and van der Waals interaction is introduced. Then, the developed DEM simulation scheme is validated by satisfactorily reproducing the experimentally observed one-dimensional compression curves and internal structure transition from an edge-to-edge/edge-to-face flocculated structure to a face-to-face dispersed structure. Finally, evolutions of coordinate number and fabric anisotropy are quantitatively evaluated in the microscopic view. The noticeable effects of ion concentration on the internal structure evlotion and mechanical behavior of marine clay have been examined and discussed. Full article

(This article belongs to the Special Issue DEM Simulations and Modelling of Granular Materials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Processes, Volume 9, Issue 12 (December 2021) – 192 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI