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Tytuł:
Curcumin Prevents Free Fatty Acid-Induced Lipid Accumulation via Targeting the miR-22-3p/CRLS1 Pathway in HepG2 Cells
Autorzy:
Mei, Yuanyuan
Sun, Xiaoting
Huang, Shi-Ying
Wu, Xiaowen
Ho, Kuo-Ting
Lu, Liming
Chen, Chaoxiang
Li, Jian
Liu, Jingwen
Li, Guiling
Powiązania:
https://bibliotekanauki.pl/articles/28408450.pdf
Data publikacji:
2024-02-13
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
polyphenol
epigenetics
liver
steatosis
mitochondria
Opis:
Dysregulated lipid metabolism in liver is an important hallmark of non-alcoholic fatty liver disease (NAFLD), which may be modulated by dietary polyphenols or microRNAs (miRNAs). However, the underlying epigenetic regulatory mechanism of polyphenols remain unclear. The current study aimed to address how miRNA mediates hepatic lipid metabolic control of curcumin, a polyphenolic food supplement. The results showed that 24 h treatment with 5 - 20 μM curcumin prevented free fatty acid-induced lipid accumulation by around 10 ~ 50% in HepG2 cells, which was attenuated by pre-transfection with 40 nM miR-22-3p mimic for 48 h. In consequence, transfection with 40 nM miR-22-3p inhibitor for 48 h significantly reduced lipid accumulation by around 10%. And 48 h overexpression of miR-22-3p targeting cardiolipin synthase 1 (CRLS1) gene, which encodes a mitochondrial phospholipid synthase, showed a similar regulatory effect. Thus, miR-22-3p and CRLS1 showed opposite effects in modulating lipid metabolism, which probably involved mitochondrial control. In summary, this study demonstrated that curcumin improved hepatic lipid metabolism via targeting the miR-22-3p/CRLS1 pathway. Identification of the epigenetic regulatory mechanism underlying lipid metabolism may thereby facilitate alleviation of metabolic disorders by natural polyphenols.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 1; 59-68
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Stewing Modes on Physicochemical Quality and Formation of Flavour Compounds of Chinese Dagu Chicken Soup
Autorzy:
Guan, Haining
Xu, Xiaojun
Feng, Chunmei
Tian, Yanli
Liu, Dengyong
Diao, Xiaoqin
Powiązania:
https://bibliotekanauki.pl/articles/28408447.pdf
Data publikacji:
2024-02-08
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
chicken soup
stewing modes
physicochemical quality
taste components
volatile compounds
Opis:
This study aimed to evaluate the influences of stewing modes, including high fire short time (HFST, 100°C/1 h), medium-high fire mid-length time (MFMT, 98°C/2 h), medium fire long time (MFLT, 90°C/3 h), and low fire ultra-length time (LFUT, 83°C/4 h) processing, on physicochemical parameters and flavour compound profile of Chinese Dagu chicken soup. The chicken soup prepared under the stewing mode of MFMT had smaller particle size (d3,2 of 2.56 μm and d4,3 of 1.73 μm), higher zeta potential (8.66 mV), and viscosity than the soups stewed under the other conditions. The umami-taste compounds, such as inosine 5'-monophosphate, and umami free amino acid were the most abundant in the soup stewed by MFMT (53.47 and 59.91 mg/100 mL, respectively). GC-MS results showed that the volatile compounds were mainly hexanal, octanal, heptanal, (E,E)-2,4-decadienal, nonanal, and 1-octen-3-ol. Additionally, the results of measurements made with the electronic nose and electronic tongue indicated that the overall flavour of the four chicken soups varied significantly. In general, considering the stability and umami taste of chicken soup, as well as the time-saving need, it is recommended to use the MFMT mode to prepare the chicken soup.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 1; 26-40
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing hotel employees well-being and safe behaviors: The influences of physical workload, mental workload, and psychological resilience
Autorzy:
El-Sherbeeny, Ahmed M.
Alsetoohy, Omar
Sheikhelsouk, Samar
Liu, Sijun
Abou Kamar, Mahmoud
Powiązania:
https://bibliotekanauki.pl/articles/39993224.pdf
Data publikacji:
2024
Wydawca:
Instytut Badań Gospodarczych
Tematy:
physical and mental workloads
overall well-being
psychological resilience
safe behaviors
luxury hotels
Opis:
Research background: Despite the dynamically growing cross-sectional academic studies conducted on various aspects related to physical and mental workloads in the context of workplace safety, there is still room for further in-depth analyses of how these workloads affect employees' behavior and well-being. This phenomenon is of particular interest in the case of hospitality, where hotels should recognize the workloads imposed on their employees, since they are considered the most critical and influential stressors in the workplace. Purpose of the article: Based on the conservation of resources (COR) theory, our study aims to examine how hotel employees' physical and mental workloads affect their well-being and safe behaviors. The study also investigates how employee well-being and psychological resilience play a role in these patterns. Methods: The study employs an experience-sampling methodology to assess the physical and mental workloads of a group of full-time employees working in luxury hotels in the USA. Findings & value added: The findings derived from Partial Least Squares Structural Equation Modeling (PLS-SEM) reveal that both physical and mental workloads negatively impact overall well-being and safe behaviors. Additionally, physical workload influences mental workload. Also, employee well-being has been identified as a mediating factor in the relationship between workloads, psychological resilience, and safe behaviors. Notably, psychological resilience has not exhibited a moderating effect. This study expands on the COR theory by examining its impact on the hospitality industry. The study has developed and validated a model for assessing hotel employees' physical workload. Moreover, it emphasizes the significance of employees' well-being and psychological resilience in promoting safe behaviors in hotels. Therefore, this model is a significant step forward toward effectively measuring and maintaining the overall well-being and safe behaviors of employees in the hospitality industry. Furthermore, the value of the research is enhanced by surveying hotel employees directly rather than relying on subjective opinions from management about employee involvement in workplace health and safety. This approach avoids the bias often present in management assessments and provides a more accurate depiction of employee participation.
Źródło:
Oeconomia Copernicana; 2024, 15, 2; 765-807
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluating the association between effort-reward imbalance and suboptimal health status among hospital nurses: a cross-sectional study
Autorzy:
Yu, Leilei
Liu, Weiting
Wang, Jingzheng
Jin, Ziyao
Meng, Ruoyu
Wu, Zhiyuan
Zheng, Yuanyuan
Guo, Zheng
Powiązania:
https://bibliotekanauki.pl/articles/31341044.pdf
Data publikacji:
2024-05-20
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
stress
nurses
occupational health
hospital
effort-reward imbalance
suboptimal health status
Opis:
Objectives Occupational stress is a common complaint in nurses, who perceived more sense of effort-reward imbalance (ERI). Suboptimal health status (SHS) is a state between health and disease. However, the correlation between ERI and SHS is unclear. Therefore, the aim of this study was to examine the prevalence of SHS and ERI and evaluate the relationship between ERI and SHS in clinical nurses by a cross-sectional study. Material and Methods The current cross-sectional study was conducted through an online survey at Dongping People’s Hospital in China. A total of 633 completed surveys were received. Effort-reward imbalance was measured by subscales of the ERI questionnaire. SHS was measured by the Suboptimal Health Status Questionnaire – 25 (SHSQ-25). The relationship between ERI and SHS in nurses was subsequently assessed by Spearman’s correlation coefficient and logistic regression model. Results The mean age of the optimal health status (OHS) group (M±SD 26.3±7.3 years) was younger than the SHS group (M±SD 30.3±6.9 years). The prevalence of SHS was 54.5% (345/633). Female nurses aged ≥30 years, a junior college or university graduate educational level, smokers, and nurses without regular exercise were at a higher risk of SHS. In Spearman’s correlation analysis, ERI reflected by the effort-reward ratio was correlated with SHSQ-25 score (r = 0.662, p < 0.001). In logistic regression, ERI was strongly associated with SHS after potential confounding factors adjusting (OR 27.924, 95% CI 22.845–34.132). Conclusions The prevalence of SHS was significantly high in clinical nurses. Administrators should pay more attention to health status of female nurses aged ≥30 years, with a junior college or bachelor’s degree, smoking, and without regular exercise to reduce the SHS and ERI.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2024, 37, 2; 165-175
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of Proteins from Sweet Potato Cell Liquid by Acidification via Inoculation-Enhanced Fermentation and Determination of Functional Properties of Protein Products
Autorzy:
Li, Qingshuai
Liu, Liping
Han, Yanlei
Zhao, Xiangying
Yao, Mingjing
Ma, Jing
Han, Mo
Zhang, Jiaxiang
Powiązania:
https://bibliotekanauki.pl/articles/28408449.pdf
Data publikacji:
2024-02-09
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
sweet potato proteins
Leuconostoc citreum
protein precipitation
digestibility
emulsification
foaming
Opis:
Starch production from fresh sweet potatoes generates process wastewater called sweet potato cell liquid (SPCL), which is rich in sweet potato protein (SPP). Currently, the commonly used protein recovery methods, such as isoelectric point precipitation and ultrafiltration, were not suitable for SPP recovery due to the low protein content of SPCL and the high cost of recovery. The feasibility of recovering SPP by SPCL acidification via inoculation-assisted fermentation was investigated in this study. The results indicated that the pH of SPCL could be reduced to approximately 4.0 within 6 h of fermentation with inoculation, resulting in an SPP extraction yield of 55.45% and purity of 66.23 g protein/100 g. With the addition of heating treatment, the extraction yield of SPP increased to 76.97–95.34%, while it maintained the purity of 66.36–70.12 g protein/100 g. The composition analysis revealed that SPP products contained sugars (below 11.5 g/100 g) in addition to protein and trace amounts of lignin and phenolics. Functional properties analysis showed that the SPP recovered by inoculation-enhanced fermentation exhibited better emulsifying and foaming properties, and higher digestibility compared to the SPP precipitated using hydrochloric acid. The method of extracting SPP from SPCL by inoculation-enhanced fermentation, as developed in this study, was a straightforward and cost-effective process that fosters significant potential for industrial applications.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 1; 49-58
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A combinatorial auction mechanism for time-varying multidimensional resource allocation and pricing in fog computing
Autorzy:
Li, Shiyong
Zhang, Yanan
Sun, Wei
Liu, Jia
Powiązania:
https://bibliotekanauki.pl/articles/15548021.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
fog computing
combinatorial auction
time varying multidimensional resource allocation
resource pricing
mgła obliczeniowa
aukcja kombinatoryczna
wycena zasobów
Opis:
It is a hot topic to investigate resource allocation in fog computing. However, currently resource allocation in fog computing mostly supports only fixed resources, that is, the resource requirements of users are satisfied with a fixed amount of resources during the usage time, which may result in low utility of resource providers and even cause a waste of resources. Therefore, we establish an integer programming model for the time-varying multidimensional resource allocation problem in fog computing to maximize the utility of the fog resource pool. We also design a heuristic algorithm to approximate the solution of the model. We apply a dominant-resource-based strategy for resource allocation to improve resource utilization as well as critical value theory for resource pricing to enhance the utility of the fog resource pool. We also prove that the algorithm satisfies truthful and individual rationality. Finally, we give some numerical examples to demonstrate the performance of the algorithm. Compared with existing studies, our approach can improve resource utilization and maximize the utility of the fog resource pool.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2023, 33, 2; 327--339
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dual-stator brushless doubly-fed generator for wind power application
Autorzy:
Liu, Hao
Song, Yakai
Bai, Chunlan
He, Guofeng
Yin, Xiaoju
Powiązania:
https://bibliotekanauki.pl/articles/27309959.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
doubly-fed machine
dual-stator
electromagnetic analysis
operational characteristics modes
wind power generation
Opis:
A novelty dual-stator brushless doubly-fed generator (DSBDFG) with magnetic-barrier rotor structure is put forward for application in wind power. Compared with a doubly-fed induction generator, the DSBDFG has virtues of high reliability and low maintenance costs because of elimination of brush and sliprings components. Therefore, the proposed structure has tremendous potential as a wind power generator to apply in wind power. According to the operating principle of electric machine, the DSBDFG is studied in wind power application. At first, the topology, the winding connecting, the rotor structure, the power flow chart of different operating models and the variable speed capability of electric machine are discussed and analyzed. Then, a 50 kW DSBDFG is designed. Based on the principal dimension of the design electric machine, the electromagnetic characteristics of the DSBDFG with different running modes are analyzed and calculated to adopt the numerical method. From the result, it meets the requests of electromagnetic consistency and winding connecting in the design electric machine. Meanwhile, it confirms the proposed DSBDFG has the strong ability of speed regulation.
Źródło:
Archives of Electrical Engineering; 2023, 72, 4; 1073--1087
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fully-coupled three-dimensional fluid-structure interaction study on the externally-pressurized collapsible tube and the internal flow
Autorzy:
Zhang, Sen
Liu, HaoFei
Powiązania:
https://bibliotekanauki.pl/articles/2200900.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fluid structure interaction
stability
eigenvalue problem
bifurcation
Opis:
We study the behavior of a collapsible tube conveying a fluid subject to external pressure that could occur in many physiological applications. The method of rotating spines is developed to enable an automatic mesh adaptation when the tube is deformed largely. We examine bifurcation diagrams when the tube is collapsed under a pressure driven condition and reveal that multiple solutions exist for a range of the Reynolds number. The stability characteristic of the system is discovered by determining stability of these solutions by the eigenvalue method for the first time, which is validated by solving a time-dependent problem of the system.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 395--406
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A lightweight multi-person pose estimation scheme based on Jetson Nano
Autorzy:
Liu, Lei
Blancaflor, Eric B.
Abisado, Mideth
Powiązania:
https://bibliotekanauki.pl/articles/30148243.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
human pose estimation
lightweight model
Edge AI
deep learning
computer vision
Opis:
As the basic technology of human action recognition, pose estimation is attracting more and more researchers' attention, while edge application scenarios pose a higher challenge. This paper proposes a lightweight multi-person pose estimation scheme to meet the needs of real-time human action recognition on the edge end. This scheme uses AlphaPose to extract human skeleton nodes, and adds ResNet and Dense Upsampling Revolution to improve its accuracy. Meanwhile, we use YOLO to enhance AlphaPose’s support for multi-person pose estimation, and optimize the proposed model with TensorRT. In addition, this paper sets Jetson Nano as the Edge AI deployment device of the proposed model and successfully realizes the model migration to the edge end. The experimental results show that the speed of the optimized object detection model can reach 20 FPS, and the optimized multi-person pose estimation model can reach 10 FPS. With the image resolution of 320×240, the model’s accuracy is 73.2%, which can meet the real-time requirements. In short, our scheme can provide a basis for lightweight multi-person action recognition scheme on the edge end.
Źródło:
Applied Computer Science; 2023, 19, 1; 1-14
1895-3735
2353-6977
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Microscopic Prediction Model for Traffic Noise in Adjacent Regions to Arterial Roads
Autorzy:
Li, Ming
Liu, Jizhou
Powiązania:
https://bibliotekanauki.pl/articles/31339809.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
traffic noise
arterial roads
noise prediction method
microscopic level
Opis:
Traffic noise in big cities impacts the people who live and work in high-rise buildings alongside arterial roads. To determine this impact magnitude, this paper proposes and validates a microscopic level method that locally predicts the total noise level and the spectral characteristics of traffic flow in the near-road region. In the proposed method, the vehicles on the road are considered as multiple queues of moving point sound sources with ground reflection considered. To account for the flow of vehicles on the road, traffic field data, and individual vehicle noise source models are also employed. A field measurement is conducted to validate the proposed method. Results comparison shows that the predicted and the measured overall A-weighted sound pressure level and A-weighted noise spectra are within 3 dBA and 5 dBA, respectively. Based on the validated method, the spatial distribution of traffic noise near the arterial road is investigated for different traffic scenarios.
Źródło:
Archives of Acoustics; 2023, 48, 3; 433-449
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A nanoparticle cationic polystyrene-co-poly(n-butylacrylate) collector to eliminate the negative effect of lizardite slimes in pyrite flotation
Autorzy:
Ai, Guanghua
Liu, Cheng
Zhu, Guangli
Yang, Siyuan
Powiązania:
https://bibliotekanauki.pl/articles/24085927.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nanoparticle collector
pyrite
lizardite slimes
flotation separation
Opis:
Lizardite slime coating is one of significant factors in the deterioration of the floatability of sulphide minerals. In this study, a nanoparticle cationic polystyrene-co-poly(n-butylacrylate)(PS-PBNH) collector was introduced to eliminate the negative impact of lizardite slimes in pyrite flotation. Microflotation results demonstrated that lizardite slims did not affect the recovery of pyrite in the presence of PS-PBNH. Good flotation separation of pyrite from lizardite was achieved when the nanoparticle PS-PBNH collector was used. The results from adsorption study indicated that PS-PBNH exhibited a significant adsorption on the pyrite surface in the presence of lizardite slimes. Sedimentation tests showed that hetero-aggregation occurred between lizardite slimes and pyrite, whereas the introduction of PS-PBNH collector resulted in a heterogeneous dispersion between them. Zeta potential measurements suggested that PS-PBNH collector interacted with pyrite surface, and the PS-PBNH adsorption changed the surface charge of pyrite from negative to be positive. As a result, the interaction of pyrite with lizardite shifted from electrostatic attraction to electrostatic repulsion, as supported by the DLVO calculations. These results indicated PS-PBNH can be used as a potential collector for pyrite flotation in pyrite/lizardite slimes system without the need for a depressant.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 170899
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel method of health indicator construction and remaining useful life prediction based on deep learning
Autorzy:
Zhan, Xianbiao
Liu, Zixuan
Yan, Hao
Wu, Zhenghao
Guo, Chiming
Jia, Xisheng
Powiązania:
https://bibliotekanauki.pl/articles/27312791.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
stacked sparse autoencoder
health indicator
long short-term memory network
remaining useful life prediction
Opis:
The construction of health indicators (HI) for traditional deep learning requires human training labels and poor interpretability. This paper proposes an HI construction method based on Stacked Sparse Autoencoder (SSAE) and combines SSAE with Long short-term memory (LSTM) network to predict the remaining useful life (RUL). Extracting features from a single domain may result in insufficient feature extraction and cannot comprehensively reflect the degradation status information of mechanical equipment. In order to solve the problem, this article extracts features from time domain, frequency domain, and time-frequency domain to construct a comprehensive original feature set. Based on monotonicity, trendiness, and robustness, the most sensitive features from the original feature set are selected and put into the SSAE network to construct HI for state partitioning, and then LSTM is used for RUL prediction. By comparing with the existing methods, it is proved that the prediction effect of the proposed method in this paper is satisfied.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 4; art. no. 171374
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A risk assessment method of aircraft structure damage maintenance interval considering fatigue crack growth and detection rate
Autorzy:
Zhang, Zhuzhu
Mao, Haitao
Liu, Yulin
Jiao, Peng
Hu, Wenlin
Shen, Pei
Powiązania:
https://bibliotekanauki.pl/articles/24200796.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
Monte Carlo
risk assessment
maintenance interval
crack propagation
detection rate
condition based maintenance
Opis:
The accurate assessment of aircraft structure damage risk is the premise of establishing reasonable, economic and reliable maintenance intervals. While many studies have proposed damage risk assessment methods for aircraft structures, these methods lack the quantification of risk. This paper proposed a risk assessment method of aircraft structure damage maintenance interval considering fatigue crack growth rate and crack detection rate. The damage process of aircraft structure was simulated by Monte Carlo simulation to realize the quantitative assessment of aircraft structure damage risk and maintenance interval. Taking an aircraft fleet as an example, the damage risk of its wing structure was simulated and analyzed. The results show that if the risk is controlled within a reasonable range, the maintenance interval should be shortened to 16 flight hours. At the same time, through the analysis of the risk classification standard and the crack detection rate, the quantitative evaluation of the risk classification standard was realized.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 1; art. no. 3
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Activation of quartz flotation by Cu2+, Ni2+ in the sodium ethylxanthogenate (EX) system
Autorzy:
Liu, Yang
Tong, Xiong
Xie, Rui-Qi
Xie, Xian
Song, Qiang
Fan, Pei-Qiang
Powiązania:
https://bibliotekanauki.pl/articles/24085981.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
flotation
ions activation
sodium ethylxanthogenate
adsorption mechanism
Opis:
During the flotation of metal sulfide minerals, due to the interference of unavoidable ions, the quartz also partially floats in some cases. The studies on the mechanism of quartz being activated and floating up are still insufficient. In this study, the influence of the Cu2+ and Ni2+ unavoidable ions on the floatation of quartz was studied by micro-flotation experiments, adsorption detection, zeta potential measurement, solution composition calculation, infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses, and atomic force microscopy (AFM) observation. This provides a theoretical reference for further understanding the mechanism of sodium ethylxanthogenate and quartz surface, as well as the development of a new quartz depressant. The results of flotation showed that after activation by Cu2+ (1×10-4 mol/dm3) and Ni2+ (5×10-5 mol/dm3), the quartz was captured by sodium ethylxanthogenate (EX: 1.4×10-4 mol/dm3) under alkaline conditions (pH=10), while the best recoveries were obtained as 80% and 43%, respectively. The results of adsorption and zeta potential measurements showed that the precipitation rate of Cu2+ was greater than that of Ni2+ under alkaline conditions. Additionally, both Cu2+ and Ni2+ electrostatically adsorbed on the quartz surface and changed the zeta potential of quartz. The solution composition calculation further showed that Cu(OH)+, Cu(OH)2(s), and Ni(OH)+, Ni(OH)2(s) were the main components in the solution under alkaline conditions. The FT-IR and XPS analyses and AFM observations demonstrated that Cu and Ni species adsorbed on O atoms on the quartz surface, providing active sites for EX adsorption, and EX combines with Cu and Ni species on the quartz surface to generate -O-Cu-EX and -O-Ni-EX complexes. Finally, the quartz floated up due to the formation of hydrophobic products and firm adsorption.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 166368
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adptive heading control of underactuated unmanned surface vehicle based on improved backpropagation neural network
Autorzy:
Dong, Zaopeng
Li, Jiakang
Liu, Wei
Zhang, Haisheng
Qi, Shijie
Zhang, Zhengqi
Powiązania:
https://bibliotekanauki.pl/articles/32917278.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underactuated unmanned surface vehicle
backpropagation neural network controller
heading control
hyperbolic tangent function
Opis:
Aiming at the challenges to the accurate and stable heading control of underactuated unmanned surface vehicles arising from the nonlinear interference caused by the overlay and the interaction of multi interference, and also the uncertainties of model parameters, a heading control algorithm for an underactuated unmanned surface vehicle based on an improved backpropagation neural network is proposed. Based on applying optimization theory to realize that the underactuated unmanned surface vehicle tracks the desired yaw angle and maintains it, the improved momentum of weight is combined with an improved tracking differentiator to improve the robustness of the system and the dynamic property of the control. A hyperbolic tangent function is used to establish the nonlinear mappings an approximate method is adopted to summarize the general mathematical expressions, and the gradient descent method is applied to ensure the convergence. The simulation results show that the proposed algorithm has the advantages of strong robustness, strong anti-interference and high control accuracy. Compared with two commonly used heading control algorithms, the accuracy of the heading control in the complex environment of the proposed algorithm is improved by more than 50%.
Źródło:
Polish Maritime Research; 2023, 1; 54-64
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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