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Showing records 37725 to 37749 of 43292. [First] Page: 1 1506 1507 1508 1509 1510 1511 1512 1513 1514 Last
Efficient Adsorption of Tl(I) from Aqueous Solutions Using Al and Fe-Based Water Treatment Residuals
Youze Xu, Yingjun Qing, Ruimin Gu, Shuang Zhou, Guangyi Fu, Yuanyuan Zhao
February 21, 2023 (v1)
Keywords: Adsorption, Al-WTR, Fe-WTR, thallium, wastewater treatment
Iron and aluminum water treatment residuals from a water supply plant were used as adsorbents for Tl(I) to treat thallium-containing Tl(I) wastewater and realize the resource utilization of water treatment residuals. The feasibility study results showed that Fe-WTR and Al-WTR reached adsorption equilibria within 120 min. The Langmuir model showed maximum adsorption capacities of Tl(I) on Fe-WTR and Al-WTR as 3.751 and 0.690 mg g−1 separately at an initial concentration of 5 mg L−1. The adsorption capacities of Fe-WTR and Al-WTR positively correlated with pH. The removal of Tl(I) using Fe-WTR exceeded Al-WTR; the adsorbed Tl(I) in Fe-WTR occurred primarily in the reduced state, while the Tl(I) adsorbed in Al-WTR was mainly in acid-extractable and reduced states. FTIR and XPS data showed that Tl(I) and Fe/Al-OH-functional groups formed stable surface complexes (Fe/Al-O-Tl) during adsorption, and there was no redox reaction. This confirmed that WTR is a highly efficient adsorbent for the... [more]
Validation of a Classical Sliding Mode Control Applied to a Physical Robotic Arm with Six Degrees of Freedom
Andres González-Rodríguez, Rogelio E. Baray-Arana, Abraham Efraím Rodríguez-Mata, Isidro Robledo-Vega, Pedro Rafael Acosta Cano de los Ríos
February 21, 2023 (v1)
Keywords: manipulator, real-time application, six degrees of freedom, sliding mode control
The control of robotic manipulators has become increasingly difficult over recent years due to their high accuracy, performance, speed, and reliability in a variety of applications, such as industry, medicine, research, etc. These serial manipulator systems are extremely complex because their dynamic models include perturbations, parametric variations, coupled nonlinear dynamics, and non-modular dynamics, all of which require robust control for trajectory tracking. This paper compares two control techniques: computational torque control (CTC) and sliding mode control (SMC). In this study, the latter was used for a physical robotic arm with six degrees of freedom (DOF) and online experiments were conducted, which have received little attention in the literature. As a result, the contribution of this work was based on the real-time application of this controller via a self-developing interface. The great resilience of sliding mode controllers to disturbances was also demonstrated in this... [more]
Experimental Characterization of a Microfluidic Device Based on Passive Crossflow Filters for Blood Fractionation
Inês M. Gonçalves, Inês Castro, Filipe Barbosa, Vera Faustino, Susana O. Catarino, Ana Moita, João M. Miranda, Graça Minas, Patrícia C. Sousa, Rui Lima
February 21, 2023 (v1)
Subject: Materials
Keywords: blood analogue, blood on chip, cell separation, crossflow microfluidic device, optical absorbance spectrophotometry, passive microfluidic device
The separation of red blood cells (RBCs) from blood plasma and the analysis of individual RBCs are of great importance, as they provide valuable information regarding the health of their donor. Recent developments in microfluidics and microfabrication have contributed to the fabrication of microsystems with complex features to promote the separation and analysis of RBCs. In this work, the separation capacity of a multi-step crossflow microfluidic device was evaluated by using a blood analogue fluid made by Brij L4 micelles and human RBCs separated from whole blood, suspended in a solution with hematocrits (Ht) of 0.5 and 1%. All the samples collected at the outlets of the device were experimentally analyzed and compared. The absorbance spectrum was also measured for the prepared blood samples. The results indicate that the tested blood analogue fluid has exhibited a flow behavior similar to that of blood. In addition, the optical absorbance spectrophotometry revealed that it was possib... [more]
Effects of Reynolds Number on the Overall Characteristics of Flow and Heat Transfer in the Long Micro-Tube with Dimples
Ruibai Qi, Fangfang Chen, Linjie Xu, Jiawen Yu, Xiaoping Chen
February 21, 2023 (v1)
Keywords: flow, heat transfer, micro-tube, Reynolds number
The flow and heat transfer characteristics in micro-tube are very important research fields. In order to study the influence of the Reynolds number on the overall characteristics of flow and heat transfer, a 510 mm long micro-tube with dimples was constructed. Thirty-five different working conditions are considered, and the Reynolds number is between 1500 and 8100. At the same time, the change of physical properties of coolant with temperature is considered. The reliability of numerical simulation results is verified by the grid independence verification and the comparison of experimental data. The results show that the dimple will promote the instability of the flow state and improve the heat transfer efficiency. The flow state evolution formed in the stream-wise direction is basically similar, and its fully developed position remains at 76 mm, which is independent of the Reynolds number. For the fully developed region, the partial derivation of static pressure in the stream-wise comp... [more]
Simulated Handling to Investigate the Effect of Mechanical Damage on Stored Pomegranate Fruit
Pankaj B. Pathare, Mai Al-Dairi, Rashid Al-Yahyai, Adil Al-Mahdouri
February 21, 2023 (v1)
Keywords: bruising, mechanical damage, pendulum test, storage, titratable acidity
Mechanical damage is a threat to both food security and sustainability. Bruising is the most common type of mechanical damage, and it causes a huge economic loss due to rejection of fresh produce and downgrading of the appearance quality by consumers. Therefore, this study aims to examine the effect of bruising during postharvest handling using a pendulum test technique. Pomegranate fruit were bruised once at two impact levels (1.189 ± 0.109 and 2.298 ± 0.239 J) and then stored (at 5 °C ± 1 °C and 22 °C ± 1 °C) for 28 days. The study evaluated the effect of impact bruising, storage temperature, and duration on the bruise magnitude and quality attributes of the bruised and non-bruised pomegranates. The results showed that the investigated factors affect the bruise size of bruised pomegranates. Increasing storage temperature from 5 to 22 °C and impact level from 1.189 to 2.298 J increased the bruise area, bruise volume, and bruise susceptibility over time. Alterations in total soluble so... [more]
Exploration of Cucumber Waste as a Potential Biorefinery Feedstock
Yang Gao, Hannah K. Briers, Avtar S. Matharu, Jiajun Fan
February 21, 2023 (v1)
Subject: Materials
Keywords: biorefinery, cellulosic materials, cucumber, essential oils, hydro-distillation, vacuum microwave hydro-distillation
The exploration of cucumber waste as a potential biorefinery feedstock is reported. Initially, extractives (essential oils) were isolated from cucumber waste via vacuum microwave hydro-distillation (VMHD). The yield and quality of the extractive were compared with respect to traditional hydro-distillation (HD). The essential oils were obtained over a range of microwave power (500, 750, 1000 W) and vacuum pressures (100, 200, 300 mbar). The highest quality (0.49 wt %) was obtained at a microwave irradiation power of 500 W and a vacuum of 300 mbar. VMHD is much quicker and more energy-efficient than HD. Within the context of a zero-waste biorefinery, the extractive-free residues were the solid residues from two different extraction methods were compared and characterized by ATR-IR, 13C solid-state NMR spectroscopy, SEM, TGA, and CHN elemental analysis. The resultant residues are cellulosic-rich, and no significant changes were observed with VMHD and HD treatment. The results indicated th... [more]
Insight into the Acidity and Catalytic Performance on Butane Isomerization of Thermal Stable Sulfated Monoclinic Zirconia
Daofeng Huang, Wenhua Feng, Li Zhang, Bin Yue, Heyong He
February 21, 2023 (v1)
Subject: Materials
Keywords: butane isomerization, monoclinic, solid-state NMR, sulfated zirconia
Sulfated monoclinic zirconia (M-SZ) with high thermal stability and high catalytic performance on butane isomerization were obtained by hydrothermal method followed with sulfation treatment. The acidity of M-SZ was studied by 31P MAS NMR, with trimethylphosphine (TMP) as the probe molecule, and the catalytic performance of 1-13C-n-butane over M-SZ was monitored by 13C MAS NMR spectroscopy. Both Brønsted and Lewis acids were observed on M-SZ. Only Brønsted acid strength shows close relation to the activation energy of butane isomerization, and the M-SZ catalyst with the strongest Brønsted acid strength shows the lowest activation energy of 46.4 kJ·mol−1. The catalytic stability tests were evaluated at 673 K for 240 h, which shows that sulfated monoclinic zirconia has higher thermal stability than sulfated tetragonal zirconia.
Potential Efficacy of Bacillus coagulans BACO-17 to Modulate Gut Microbiota in Rats Fed High-Fat Diet
Zu Chan, Chiou-Yeong Saw, Yi-Ching Wu, Der-Kai Lau, Wei-Jen Chen, Hui-Fang Chu, Cheng-Yen Liu, Ai-Lun Tseng, Chi-Fai Chau
February 21, 2023 (v1)
Keywords: Bacillus coagulans BACO-17, fat accumulation, high-fat diet, microbiota
This study aimed to evaluate the potential efficacy of Bacillus coagulans BACO-17 in ameliorating body fat accumulation as well as gut microbiota dysbiosis in animals, which were given a high-fat diet to mimic the adverse effect of an unhealthy dietary pattern. Compared with normal control, high-fat consumption resulted in significant (p < 0.05) elevations in weight gain (168%), feed efficiency (176%), visceral fat accumulation (228%), and a lesser total fecal short-chain fatty acids (SCFAs) (−27.5%). A significant shift of fecal Fimicutes:Bacteroidetes ratio from 1.13 to 3.14 was also observed. After 12 weeks of experiment, a supplementation of B. coagulans BACO-17 at high dose (9 log CFU/day) along with a high-fat diet could exert an apparent fat reduction ability by decreasing weight gain (by 23.7%) and visceral fat mass (by 24.0%). It was found that B. coagulans BACO-17 was able to increase fecal SCFA concentrations and revert Fimicutes:Bacteroidetes ratio back to the level... [more]
Study of the Dynamic Behavior of an Autonomous Inflow-Control Device Using a Digital Twin
Luis Alfonso Ramirez Cerquera, Jorge Andrés Pinilla, Nicolás Ríos Ratkovich, Miguel Asuaje
February 21, 2023 (v1)
Keywords: Computational Fluid Dynamics, heavy oil, inflow-control device, RCP, water management
Solutions that aim to reduce water production in heavy oil wells have led to the design of devices known as rate-controlled production (RCP) autonomous inflow-control device (AICD) valves, which are placed in well completions and autonomously open with the oil inflow and close with water by choking the flow. These devices, which are based on Bernoulli’s principle, use a levitating disk that chokes the flow of the phase with the lowest flow resistance. This study proposes a numerical model based on computational fluid dynamics (CFD) technology to understand these devices’ operations and propose better designs without experimentation. The numerical model was based on dynamic fluid−body interaction (DFBI) and volume of fluid (VOF) models. The model was found to respond as expected depending on the physical properties of the fluids involved in heavy oil production. Finally, some limitations were found in the numerical study that can be improved in future studies.
Unsteady Mass Transfer in Bubble Wakes Analyzed by Lagrangian Coherent Structures in a Flat-Bed Reactor
Lotta Kursula, Felix Kexel, Jürgen Fitschen, Marko Hoffmann, Michael Schlüter, Alexandra von Kameke
February 21, 2023 (v1)
Keywords: flat-bed reactor, gas-liquid reactions, Lagrangian Coherent Structures, mass transfer phenomena, reactive bubbly flows
To increase the yield and selectivity in reactive bubbly flows, the gas-liquid interactions have to be understood in depth. In the current fundamental study, flow and concentration data of the wakes of two-dimensional bubbles in an organic solvent are obtained experimentally in a flat-bed reactor. The unsteady mass transport phenomena in these turbulent wakes of two freely rising, two-dimensional bubbles with bubble Reynolds numbers Re=949 and Re=388 are evaluated by analyzing Lagrangian Coherent Structures (LCS). To reveal how LCS govern the transport of dissolved gas in bubble wakes, and therefore affect gas-liquid reactions, LCS in two-dimensional velocity fields are computed and compared with concentration fields of dissolved gas. The analysis of backward Finite Time Lyapunov Exponent (bFTLE) fields reveals coherent fluid dynamic structures for both bubble Reynolds numbers studied. In the higher bubble Reynolds number case, two types of coherent structures are found, which hinder t... [more]
Research on the Application of Coal Gasification Slag in Soil Improvement
Ruimei Zhang, Xiaonan Li, Kai Zhang, Pengfei Wang, Peifeng Xue, Hailong Zhang
February 21, 2023 (v1)
Keywords: coal gasification slag, contaminant analysis, microscopic characterization
SEM, particle size analysis, and contaminant content of coarse coal gasification slag (CCGS) produced by Shenhua Xinjiang Chemical Co., Ltd. were measured, respectively, and the physicochemical properties of the soil after improvement using gasification slag were investigated in this paper. The results showed that the slag was porous, the particle size was small and the pollutant content was extremely low. Its pollutants were closely related to the pollutants in the raw coal. The coarse slag had a limited effect on soil particle size and texture improvement; the soil water retention performance increased with the increase of proportion of the slag, while pH and conductivity decreased; the improvement effect on soil SOM and available potassium was remarkable; the larger the proportion of the slag, the stronger the effect on maintaining soil alkali-hydrolyzed nitrogen, ammonium nitrogen, and available phosphorus. However, the effect was small, and increased the ion content, especially th... [more]
ZIF for CO2 Capture: Structure, Mechanism, Optimization, and Modeling
Kishor Kalauni, Ajitanshu Vedrtnam, Magdalena Wdowin, Shashikant Chaturvedi
February 21, 2023 (v1)
Keywords: characterisation, CO2 absorption, metal-organic framework, zeolites, ZIF
The requirement to counter carbon emissions is becoming urgent. Zeolitic Imidazolate Frameworks (ZIFs) have been extensively investigated recently for storing and separating gases, especially carbon dioxide. The present review aims to summarise the state of the art of ZIFs for carbon dioxide capture focusing on the structure, mechanism, optimisation, and modelling. The methods utilised for carbon capture are briefly summarized. The morphology of ZIFs with different topologies, N2-CO2 adsorption-desorption isotherms, X-ray diffraction patterns, thermo-gravimetric analysis (TGA) results are discussed to give insights into the textural properties, structure-activity relationship and structural-thermal stability of ZIFs. Finally, the experimental optimisation techniques, modelling and simulation studies for improving CO2 capture by ZIFs are discussed. This review should provide a comprehensive and quick understanding of this research area. It is timely to summarize and review ongoing devel... [more]
Blockchain Technology for Oil and Gas: Implications and Adoption Framework Using Agile and Lean Supply Chains
Javed Aslam, Aqeela Saleem, Nokhaiz Tariq Khan, Yun Bae Kim
February 21, 2023 (v1)
Keywords: agile supply chain, blockchain technology, lean supply chain, oil and gas, supply chain management
Oil and gas (O&G) supply chain management (SCM) is complex because it deals with different geographic locations to manage demand and supply, transportation, inventory, and distribution. Blockchain technology has created an interesting research gap in the SCM domain, and this study is designed to describe the relevancy of blockchain technology for O&G SCM. SCM is based on agile and lean supply chains (SCs). Agile SC focuses on increasing flexibility and responsiveness to gain competitive advantages, and lean SC is based on eliminating waste and processes to improve firm performance. This study is an initial effort to propose a framework that suggests the implication of blockchain for O&G by providing an overview of O&G SCM. Data were collected from SC managers of O&G companies, and we analyzed the impact of agile and lean SCs on firm performance. The results indicate that agile SC is highly important for O&G industries in comparison to lean SC. This study proposes the key requirements o... [more]
Investigation of Catalytic and Photocatalytic Degradation of Methyl Orange Using Doped LaMnO3 Compounds
Paula Sfirloaga, Madalina-Gabriela Ivanovici, Maria Poienar, Catalin Ianasi, Paulina Vlazan
February 21, 2023 (v1)
Subject: Materials
Keywords: Catalysis, doping, kinetic parameters, MO degradation, perovskite
LaMnO3 and 1% Pd-, Ag-, or Y-doped perovskite type nanomaterials were prepared by the sol-gel method, followed by heat treatment at a low temperature (600 °C for 6 h). The investigation through X-ray diffraction and FT-IR spectroscopy indicated that all samples were well crystallized, without secondary phases, and that the transition metal doping changed the crystal structure from the R-3c space group for the undoped LaMnO3 to the Pm-3m space group for the doped perovskite compounds. In this research paper, the efficiencies of the perovskite LaMnO3 materials for methyl orange removal were analyzed, wherein the effect of the doping ions and of the pH on the catalytic activity were studied together with a kinetic approach for the LaMnO3 materials at different values of the pH. Moreover, in the catalytic activity, it should be noted that a slightly better performance was obtained for the Ag-doped materials compared to the Y- and Pd-doped perovskite samples. The results presented for the p... [more]
How to Choose the Suitable Steel of Wellhead, Wellbore, and Downhole Tools for Acid Gas Reinjection Flooding
Yudi Geng, Zhendong Liu, Wenguang Zeng, Yibo Feng, Baodong Ding, Wenxia Li, Qinying Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: acid gas reinjection flooding, CO2-H2S corrosion, material selection scheme, packer device, pitting corrosion
The material selection of injection gas wells in acid gas flooding is the bottleneck of the successful implementation of the technical scheme. Through standard and literature research, the materials of the wellhead, wellbore, and packer for reinjection well in acid gas flooding are preliminarily established, and then the suitable materials are further screened by using the weight-loss and surface characterization method. Finally, a new type of packer is designed to optimize the wellbore material. The results show that 35CrMo (CR = 0.0589 mm/y) steel is used for wellhead materials, 625 alloy steel is selected as the sealing surface, and 625 or 825 alloys (with CR ≤ 0.0055 mm/y) steel is used for wellhead sealing material. The main material of the packer is 718 Alloy (with CR ≤ 0.0021 mm/y). The cost of T95 steel within 20 years (1263 ten thousand yuan) of service is much smaller than that of G3 alloy (1771 ten thousand yuan), but after 30 years of service, its cost is close to that of G... [more]
Life Cycle Assessment (LCA) of Biochar Production from a Circular Economy Perspective
Joana Carvalho, Lucas Nascimento, Margarida Soares, Nádia Valério, André Ribeiro, Luciana Faria, André Silva, Nuno Pacheco, Jorge Araújo, Cândida Vilarinho
February 21, 2023 (v1)
Subject: Environment
Keywords: biochar, Biomass, circular economy, life cycle assessment (LCA)
Climate change and environmental sustainability are among the most prominent issues of today. It is increasingly fundamental and urgent to develop a sustainable economy, capable of change the linear paradigm, actively promoting the efficient use of resources, highlighting product, component and material reuse. Among the many approaches to circular economy and zero-waste concepts, biochar is a great example and might be a way to push the economy to neutralize carbon balance. Biochar is a solid material produced during thermochemical decomposition of biomass in an oxygen-limited environment. Several authors have used life cycle assessment (LCA) method to evaluate the environmental impact of biochar production. Based on these studies, this work intends to critically analyze the LCA of biochar production from different sources using different technologies. Although these studies reveal differences in the contexts and characteristics of production, preventing direct comparison of results, a... [more]
Cavity Size Effect on Host-Guest Property of Tiara-like Structural Mn(SR)2n Nanoclusters Probed by NMR Spectroscopy
Changlin Zhou, Shida Gong, Jishi Chen, Zonghua Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: cavity size effect, host-guest property, Mn(SR)2n, NMR, tiara-like structure
The lack of detect technology hinders the understanding of host-guest (H-G) chemical properties for thiolate-protected tiara-like structural nanoclusters (Mn(SR)2n). In this work, NMR spectroscopy is demonstrated as a powerful tool to probe the H-G structure of Mn(SR)2n both experimentally and theoretically. A low-field shifting and wide chemical shift (CS) signal of the H nucleus in CH2Cl2 is observed in the NMR spectrum of the mixture of CH2Cl2 and Pd8(PET)16 (PET is 2-phenylethanethiol), agreeing with the theoretical results that a deshielding area appears in the central cavity of Pd8(SR)16. All Mn(SR)2n own similar nucleus-independent chemical shift maps and deshielding cavities, which means that the H nucleus in small molecules trapped by Mn(SR)2n should have consistent low-field shifted CSs. However, such a phenomenon was only observed in the NMR spectrum of the mixed solution of Pd8(SR)16 and CH2Cl2, indicating that Pd8(SR)16 is the only one in the series of Pdn(SR)2n (n = 4~16)... [more]
A Review on Pollution Treatment in Cement Industrial Areas: From Prevention Techniques to Python-Based Monitoring and Controlling Models
Xinghan Zhu, Jinzhong Yang, Qifei Huang, Tao Liu
February 21, 2023 (v1)
Keywords: cement plant, Modelling, pollution monitoring, pollution treatment, python
Anthropogenic climate change, global warming, environmental pollution, and fossil fuel depletion have been identified as critical current scenarios and future challenges. Cement plants are one of the most impressive zones, emitting 15% of the worldwide contaminations into the environment among various industries. These contaminants adversely affect human well-being, flora, and fauna. Meanwhile, the use of cement-based substances in various fields, such as civil engineering, medical applications, etc., is inevitable due to the continuous increment of population and urbanization. To cope with this challenge, numerous filtering methods, recycling techniques, and modeling approaches have been introduced. Among the various statistical, mathematical, and computational modeling solutions, Python has received tremendous attention because of the benefit of smart libraries, heterogeneous data integration, and meta-models. The Python-based models are able to optimize the raw material contents and... [more]
Effect of Microparticles on Fungal Fermentation for Fermentation-Based Product Productions
Attia Iram, Ali Özcan, Ercan Yatmaz, İrfan Turhan, Ali Demirci
February 21, 2023 (v1)
Subject: Environment
Keywords: fermentation-based products, filamentous fungal fermentation, microparticle-enhanced cultivation, microparticles, MPEC
Ranging from simple food ingredients to complex pharmaceuticals, value-added products via microbial fermentation have many advantages over their chemically synthesized alternatives. Some of such advantages are environment-friendly production pathways, more specificity in the case of enzymes as compared to the chemical catalysts and reduction of harmful chemicals, such as heavy metals or strong acids and bases. Fungal fermentation systems include yeast and filamentous fungal cells based on cell morphology and culture conditions. However, filamentous fungal fermentation has gained attention in the past few decades because of the diversity of microbial products and robust production of some of the most value-added commodities. This type of fungal fermentation is usually carried out by solid-state fermentation. However, solid-state fermentation poses problems during the scale-up for industrial production. Therefore, submerged fermentation for value-added products is usually preferred for s... [more]
Information Visualisation for Antibiotic Detection Biochip Design and Testing
Paul Craig, Ruben Ng, Boris Tefsen, Sam Linsen, Yu Liu, Joshua Hendel
February 21, 2023 (v1)
Keywords: bioinformatics, information visualisation, Machine Learning
Biochips are engineered substrates that have different spots that change colour according to biochemical reactions. These spots can be read together to detect different analytes (such as different types of antibiotic, pathogens, or biological agents). While some chips are designed so that each spot on its own can detect a particular analyte, chip designs that use a combination of spots to detect different analytes can be more efficient and detect a larger number of analytes with a smaller number of spots. These types of chip can, however, be more difficult to design, as an efficient and effective combination of biosensors needs to be selected for the chip. These need to be able to differentiate between a range of different analytes so the values can be combined in a way that demonstrates the confidence that a particular analyte is present or not. The study described in this paper examines the potential for information visualisation to support the process of designing and reading biochi... [more]
Flow-Shop Scheduling Problem Applied to the Planning of Repair and Maintenance of Electromedical Equipment in the Hospital Industry
Rafael Mellado-Silva, Claudio Cubillos, Daniel Cabrera-Paniagua, Enrique Urra
February 21, 2023 (v1)
Keywords: electromedical equipment, flow-shop, production planning, production scheduling
In the literature, several approaches have been proposed to integrate and optimize product supply and construction processes associated with demand management. However, in Industry 4.0, there needs to be more studies related to applying techniques that directly affect the programming and reprogramming process that integrates the industries at the operational level. This document proposes a flow-shop scheduling procedure to address the problem of planning the repair of medical equipment in public hospitals whose main objective is to eliminate downtime and minimize total production time. The research stems from the practical problem of responding to clinical users who make use of critical equipment, such as mechanical respirators, due to COVID-19, and the limited quantity of this equipment, which makes it necessary to have repair planning processes that seek to keep the equipment in operation for the most extended amount of time. The novelty of this study is that it was applied to a crit... [more]
Determination of 7 Kinds of Alkaloids in Semen Nelumbinis and Its Products by HPLC
Feifei Zhong, Li Ouyang, Nan Deng, Fangping Yin, Jiajie He, Deqing Lei, Jieying Gao, Hui Zeng, Zhaoxia Wang, Lu Wang, Lixia Yang, Hui Zhou
February 21, 2023 (v1)
Subject: Materials
Keywords: alkaloids, high performance liquid chromatography (HPLC), Semen Nelumbinis, single factor experiment
Objective: To establish a method for the simultaneous determination of seven alkaloids in Semen Nelumbinis and its products, the extraction technology and HPLC method were optimized by the single factor experiment. Methods: Firstly, the samples were extracted ultrasonically with 1% formic acid ethanol and purified by PXC SPE column. Then, the extracts and the purified liquid were taken after concentration with nitrogen for quantitative analysis of seven alkaloids by HPLC method. Next, the contents of alkaloids in five samples were determined. Results: The method was fully validated and the result showed that seven kinds of alkaloids had good linear relation in the corresponding range of mass concentration, r2 > 0.999, where the detection limit was 0.5−1.5 mg/kg, the quantification limit was 1.25−4.5 mg/kg, the recovery was 83.33−116.04%, and the RSD of detection method was 1.06−5.25% (n = 7). In five samples, the contents of Lotusine and Neferine were the highest, Berberine Hydrochlori... [more]
Failure Mode Analysis of Intelligent Ship Positioning System Considering Correlations Based on Fixed-Weight FMECA
Xiaofang Luo, Haolang He, Xu Zhang, Yong Ma, Xu Bai
February 21, 2023 (v1)
Keywords: fixed-weight, FMECA, intelligent ship, positioning system, risk identification
Currently, intelligent ships are still in the early stages of development in terms of autonomous navigation and autonomous berthing, so almost no source of fault data can be obtained. Conducting an in-depth analysis of the failure modes of intelligent ships is critical to optimizing the design of smart ships and ensuring their normal and safe navigation. In this paper, the fixed-weight Failure Mode Effects and Criticality Analysis (FMECA) is combined with the decision-making trial and evaluation laboratory (DEMATEL) method to analyze the failure modes and effects of intelligent ship positioning systems. This combined method not only overcomes the failure of traditional FMECA methods to differentiate between severity, incidence, and detection rates but also allows the correlation of failure causes to be analyzed, bringing the results of the analysis closer to reality. Through the expert scoring of failure modes, the failure modes of this system are risk-ranked, and the key failure cause... [more]
An Improved Line-Up Competition Algorithm for Unrelated Parallel Machine Scheduling with Setup Times
Yuting Xu, Bin Shi
February 21, 2023 (v1)
Keywords: heuristic rules, line-up competition algorithms, production scheduling, unrelated parallel machine scheduling, variant policies
It is well known that with the development of economic globalization and increasing competition in the market, enterprises are facing a huge challenge in the unrelated parallel machine scheduling problem with setup time (UPMST). Determining the processing order of all jobs and assigning machines to production scheduling has become more complex and has research implications. Moreover, a reasonable production scheduling scheme can not only complete the production plan efficiently but also contribute to reducing carbon emissions. In this paper, a mathematical model with the goal of the shortest completion time is studied for the UPMST problem. An improved line-up competition algorithm (ILCA) is proposed to solve this model, and the search accuracy and rate of the algorithm are improved by the newly proposed heuristic workpiece allocation rules and variation strategies. From the perspective of evaluation purposes, the effectiveness and stability of the method are significantly superior to... [more]
Solid-State Fermentation from Organic Wastes: A New Generation of Bioproducts
Nicolás Oiza, Javier Moral-Vico, Antoni Sánchez, Edgar Ricardo Oviedo, Teresa Gea
February 21, 2023 (v1)
Keywords: biopesticide, bioproducts, biosurfactant, circular bioeconomy, organic waste, solid-state fermentation
Solid-state fermentation (SSF) is part of the pathway to consolidate waste as a relevant alternative for the valorization of organic waste. The objective of SSF is to produce one or several bioproducts of added value from solid substrates. Solid-state fermentation can use a wide variety of organic waste as substrates thus, it is an excellent candidate in the framework of the circular bioeconomy to change the status of waste from feedstock. The development of SSF was boosted in the previous decade by scientific efforts devoted to the production of hydrolytic enzymes. Nowadays, SSF has expanded to other valuable products: biosurfactants, biopesticides, aromas, pigments, and bio-flocculants, among others. This review explores the conditions to obtain the main emerging SSF products and highlight and discuss the challenges related to the scale-up of these processes and the bioproducts downstream, which hamper their further commercialization.
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