Production Scheduling in Integrated Steel Manufacturing

Steel manufacturing is both energy and capital intensive, and it includes multiple production stages, such as iron-making, steelmaking, and rolling. This dissertation investigates the order schedule coordination problem in a multi-stage manufacturing context. A mixed-integer linear programming model is proposed to generate operational (up to the minute) schedules for the steelmaking and rolling stages simultaneously. The proposed multi-stage scheduling model in integrated steel manufacturing can provide a broader view of the cost impact on the individual stages. It also extends the current order scheduling literature in steel manufacturing from a single-stage focus to the coordinated multi-stage focus. Experiments are introduced to study the impact of problem size (number of order batches), order due time and demand pattern on solution performance. Preliminary results from small data instances are reported. A novel heuristic algorithm, Wind Driven Algorithm (WDO), is explained in detail, and numerical parameter study is presented. Another well-known and effective heuristic approach based on Particle Swarm Optimization (PSO) is used as a benchmark for performance comparison. Both algorithms are implemented to solve the scheduling model. Results show that WDO outperforms PSO for the proposed model on solving large sample data instances. Novel contributions and future research areas are highlighted in the conclusion

Opportunities and Challenges of Blockchain Technology in China's Frozen Seafood Supply Chain in the aftermath of COVID-19

Purpose: The researcher found that China's frozen seafood supply chain is experiencing an unprecedented crisis in the aftermath of the COVID-19. Through in-depth interviews and case studies of six companies, the primary purpose of this dissertation is to explore critical factors affecting the frozen seafood supply chain in China, and to discuss the adoption of blockchain technology in the frozen seafood supply chain as an emerging technology capable of making the food supply chain transparent and secure as well as responsive to customer needs and regulatory requirements. So far, the existing literature has mainly explored the advantages of blockchain technology. However, its application is still challenging, especially for developing countries like China. Besides, there is still little research on blockchain in the frozen seafood supply chain. Therefore, this study investigates the opportunities and challenges of applying blockchain technology in the frozen seafood supply chain and provides insights into solutions to overcome the challenges. It presents empirical research on the implementation of blockchain in the industry in order to encourage blockchain development and have a beneficial influence on the sustainability of the frozen seafood industry. Methodology: This study adopts a mixed research method, i.e., literature review, semi-structured interviews and case studies. The literature review provides a theoretical framework for this study on the COVID-19, frozen seafood supply chain, its disruption modes, and blockchain technology. Semi-structured interviews and case studies cover six seafood companies in China. Both within-case and cross-case analysis are used to present the disruption patterns of China's frozen seafood supply chain as well as the opportunities and challenges framework of blockchain in the frozen seafood supply chain. Findings: The dissertation, based on semi-structured interviews and case studies, enumerates the disruption faced by the frozen seafood supply chain as a result of COVID-19, proving that COVID-19 first affected the circulation of frozen seafood products, which was mainly short-term because it would be gradually eased as the epidemic situation improved. The epidemic has had a more profound impact on consumption because of the significant change in consumption concept after the epidemic. Consumers' demand for food safety and health and concern about the source of food will increase, so the traceability of the supply chain will become the trend. Blockchain technology is a contributing factor to supply chain visibility and has shown advantages for government regulatory efficiency, corporate supply chain management and consumers' access to food sources. However, implementation challenges remain, mainly manifested in technical complexity, high cost, uncertain return on investment, regulatory uncertainty, security and privacy issues, increased user liability, self-condition constraints, and the inability to achieve true traceability. Based on these challenges, the researcher proposes potential solutions from regulatory, enterprise and technology perspectives, and constructs a framework for blockchain implementation in the frozen seafood supply chain. Research limitations/implications: Due to the limitation of time and resources, only six companies were invited to conduct this study, all of which are all from frozen seafood/food companies and are all in China. Therefore, the study results may not be representative enough. Originality/Value: Through interviews and case studies, the dissertation elaborates the disruption of the frozen seafood supply chain under COVID-19, provides empirical research on the practice, opportunities and challenges of blockchain in the frozen seafood supply chain, and builds a framework for blockchain in the frozen seafood supply chain. As far as the researcher knows, this thesis is one of the few in-depth analysis of implementation of blockchain in the frozen seafood industry. It provides a theoretical and empirical basis for the application of blockchain in this field to promote blockchain development, as well as an evaluation framework for frozen seafood practitioners who want to implement blockchain technology and a direction for the sustainable development of the frozen seafood industry

Molecular characteristics and function of elliptical Kiwifruit

Article describes study analyzing the chemical components of elliptical kiwifruit (Actinidia chinensis Planch) using Fourier transform infrared spectroscopy (FT-IR) and gas chromatography mass spectrometry (GC–MS) technologies

Opportunities and Challenges of Blockchain Technology in China's Frozen Seafood Supply Chain in the aftermath of COVID-19

Purpose: The researcher found that China's frozen seafood supply chain is experiencing an unprecedented crisis in the aftermath of the COVID-19. Through in-depth interviews and case studies of six companies, the primary purpose of this dissertation is to explore critical factors affecting the frozen seafood supply chain in China, and to discuss the adoption of blockchain technology in the frozen seafood supply chain as an emerging technology capable of making the food supply chain transparent and secure as well as responsive to customer needs and regulatory requirements. So far, the existing literature has mainly explored the advantages of blockchain technology. However, its application is still challenging, especially for developing countries like China. Besides, there is still little research on blockchain in the frozen seafood supply chain. Therefore, this study investigates the opportunities and challenges of applying blockchain technology in the frozen seafood supply chain and provides insights into solutions to overcome the challenges. It presents empirical research on the implementation of blockchain in the industry in order to encourage blockchain development and have a beneficial influence on the sustainability of the frozen seafood industry. Methodology: This study adopts a mixed research method, i.e., literature review, semi-structured interviews and case studies. The literature review provides a theoretical framework for this study on the COVID-19, frozen seafood supply chain, its disruption modes, and blockchain technology. Semi-structured interviews and case studies cover six seafood companies in China. Both within-case and cross-case analysis are used to present the disruption patterns of China's frozen seafood supply chain as well as the opportunities and challenges framework of blockchain in the frozen seafood supply chain. Findings: The dissertation, based on semi-structured interviews and case studies, enumerates the disruption faced by the frozen seafood supply chain as a result of COVID-19, proving that COVID-19 first affected the circulation of frozen seafood products, which was mainly short-term because it would be gradually eased as the epidemic situation improved. The epidemic has had a more profound impact on consumption because of the significant change in consumption concept after the epidemic. Consumers' demand for food safety and health and concern about the source of food will increase, so the traceability of the supply chain will become the trend. Blockchain technology is a contributing factor to supply chain visibility and has shown advantages for government regulatory efficiency, corporate supply chain management and consumers' access to food sources. However, implementation challenges remain, mainly manifested in technical complexity, high cost, uncertain return on investment, regulatory uncertainty, security and privacy issues, increased user liability, self-condition constraints, and the inability to achieve true traceability. Based on these challenges, the researcher proposes potential solutions from regulatory, enterprise and technology perspectives, and constructs a framework for blockchain implementation in the frozen seafood supply chain. Research limitations/implications: Due to the limitation of time and resources, only six companies were invited to conduct this study, all of which are all from frozen seafood/food companies and are all in China. Therefore, the study results may not be representative enough. Originality/Value: Through interviews and case studies, the dissertation elaborates the disruption of the frozen seafood supply chain under COVID-19, provides empirical research on the practice, opportunities and challenges of blockchain in the frozen seafood supply chain, and builds a framework for blockchain in the frozen seafood supply chain. As far as the researcher knows, this thesis is one of the few in-depth analysis of implementation of blockchain in the frozen seafood industry. It provides a theoretical and empirical basis for the application of blockchain in this field to promote blockchain development, as well as an evaluation framework for frozen seafood practitioners who want to implement blockchain technology and a direction for the sustainable development of the frozen seafood industry

Synthesis of High-Energy Faceted TiO₂ Nanocrystals with Enhanced Photocatalytic Performance for the Removal of Methyl Orange

In this work, brookite TiO2 nanocrystals with co-exposed {001} and {120} facets (pH0.5-T500-TiO2 and pH11.5-T500-TiO2), rutile TiO2 nanorod with exposed {110} facets and anatase TiO2 nanocrystals with exposed {101} facets (pH3.5-T500-TiO2) and {101}/{010} facets (pH5.5-T500-TiO2, pH7.5-T500-TiO2 and pH9.5-T500-TiO2) were successfully synthesized through a one-pot solvothermal method by using titanium (V) iso-propoxide (TTIP) colloidal solution as the precursor. The crystal structure, morphology, specific surface area, surface chemical states and photoelectric properties of the pHx-T500-TiO2 (x = 0.5, 1.5, 3.5, 5.5, 7.5, 9.5, 11.5) were characterized by powder X-ray diffraction (XRD), field scanning transmission electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), nitrogen adsorption instrument, X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectra and electrochemical impedance spectroscopy (EIS). The photocatalytic activity performance of the pHx-T500-TiO2 samples was also investigated. The results showed that as-prepared pH3.5-T500-TiO2 nanocrystal with exposed {101} facets exhibited the highest photocatalytic activity (95.75%) in the process of photocatalytic degradation of methyl orange (MO), which was 1.1, 1.2, 1.2, 1.3, 1.4, 1.6, 10.7, 15.1 and 27.8 fold higher than that of pH5.5-T500-TiO2 (89.47%), P25-TiO2 (81.16%), pH9.5-T500-TiO2 (79.41%), pH7.5-T500-TiO2 (73.53%), pH0.5-T500-TiO2 (69.10%), CM-TiO2 (61.09%), pH11.5-T500-TiO2 (8.99%), pH1.5-T500-TiO2 (6.33%) and the Blank (3.44%) sample, respectively. The highest photocatalytic activity of pH3.5-T500-TiO2 could be attributed to the synergistic effects of its anatase phase structure, the smallest particle size, the largest specific surface area and exposed {101} facets

A Sustainable and Low-Cost Route to Design NiFe₂O₄ Nanoparticles/Biomass-Based Carbon Fibers with Broadband Microwave Absorption

Carbon-based microwave-absorbing materials with a low cost, simple preparation process, and excellent microwave absorption performance have important application value. In this paper, biomass-based carbon fibers were prepared using cotton fiber, hemp fiber, and bamboo fiber as carbon sources. Then, the precise loading of NiFe2O4 nanoparticles on biomass-based carbon fibers with the loading amount in a wide range was successfully realized through a sustainable and low-cost route. The effects of the composition and structure of NiFe2O4/biomass-based carbon fibers on electromagnetic parameters and electromagnetic absorption properties were systematically studied. The results show that the impedance matching is optimized, and the microwave absorption performance is improved after loading NiFe2O4 nanoparticles on biomass-based carbon fibers. In particular, when the weight percentage of NiFe2O4 nanoparticles in NiFe2O4/carbonized cotton fibers is 42.3%, the effective bandwidth of NiFe2O4/carbonized cotton fibers can reach 6.5 GHz with a minimum reflection loss of −45.3 dB. The enhancement of microwave absorption performance is mainly attributed to the appropriate electromagnetic parameters with the ε’ ranging from 9.2 to 4.8, and the balance of impedance matching and electromagnetic loss. Given the simple synthesis method, low cost, high output, and excellent microwave absorption performance, the NiFe2O4/biomass-based carbon fibers have broad application prospects as an economic and broadband microwave absorbent

Incorporation of Nanocatalysts for the Production of Bio-Oil from <i>Staphylea holocarpa</i> Wood

Biomass has been recognized as the most common source of renewable energy. In recent years, researchers have paved the way for a search for suitable biomass resources to replace traditional fossil fuel energy and provide high energy output. Although there are plenty of studies of biomass as good biomaterials, there is little detailed information about Staphylea holocarpa wood (S. holocarpa) as a potential bio-oil material. The purpose of this study is to explore the potential of S. holocarpa wood as a bio-oil. Nanocatalyst cobalt (II) oxide (Co3O4) and Nickel (II) oxide (NiO) were used to improve the production of bio-oil from S. holocarpa wood. The preparation of biofuels and the extraction of bioactive drugs were performed by the rapid gasification of nanocatalysts. The result indicated that the abundant chemical components detected in the S. holocarpa wood extract could be used in biomedicine, cosmetics, and biofuels, and have a broad industrial application prospect. In addition, nanocatalyst cobalt tetraoxide (Co3O4) could improve the catalytic cracking of S. holocarpa wood and generate more bioactive molecules at high temperature, which is conducive to the utilization and development of S. holocarpa wood as biomass. This is the first time that S. holocarpa wood was used in combination with nanocatalysts. In the future, nanocatalysts can be used to solve the problem of sustainable development of biological resources

Synthesis of High-Energy Faceted TiO2 Nanocrystals with Enhanced Photocatalytic Performance for the Removal of Methyl Orange

In this work, brookite TiO2 nanocrystals with co-exposed {001} and {120} facets (pH0.5-T500-TiO2 and pH11.5-T500-TiO2), rutile TiO2 nanorod with exposed {110} facets and anatase TiO2 nanocrystals with exposed {101} facets (pH3.5-T500-TiO2) and {101}/{010} facets (pH5.5-T500-TiO2, pH7.5-T500-TiO2 and pH9.5-T500-TiO2) were successfully synthesized through a one-pot solvothermal method by using titanium (V) iso-propoxide (TTIP) colloidal solution as the precursor. The crystal structure, morphology, specific surface area, surface chemical states and photoelectric properties of the pHx-T500-TiO2 (x = 0.5, 1.5, 3.5, 5.5, 7.5, 9.5, 11.5) were characterized by powder X-ray diffraction (XRD), field scanning transmission electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), nitrogen adsorption instrument, X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectra and electrochemical impedance spectroscopy (EIS). The photocatalytic activity performance of the pHx-T500-TiO2 samples was also investigated. The results showed that as-prepared pH3.5-T500-TiO2 nanocrystal with exposed {101} facets exhibited the highest photocatalytic activity (95.75%) in the process of photocatalytic degradation of methyl orange (MO), which was 1.1, 1.2, 1.2, 1.3, 1.4, 1.6, 10.7, 15.1 and 27.8 fold higher than that of pH5.5-T500-TiO2 (89.47%), P25-TiO2 (81.16%), pH9.5-T500-TiO2 (79.41%), pH7.5-T500-TiO2 (73.53%), pH0.5-T500-TiO2 (69.10%), CM-TiO2 (61.09%), pH11.5-T500-TiO2 (8.99%), pH1.5-T500-TiO2 (6.33%) and the Blank (3.44%) sample, respectively. The highest photocatalytic activity of pH3.5-T500-TiO2 could be attributed to the synergistic effects of its anatase phase structure, the smallest particle size, the largest specific surface area and exposed {101} facets

The Current State of Research on Sirtuin-Mediated Autophagy in Cardiovascular Diseases

Sirtuins belong to the class III histone deacetylases and possess nicotinamide adenine dinucleotide-dependent deacetylase activity. They are involved in the regulation of multiple signaling pathways implicated in cardiovascular diseases. Autophagy is a crucial adaptive cellular response to stress stimuli. Mounting evidence suggests a strong correlation between Sirtuins and autophagy, potentially involving cross-regulation and crosstalk. Sirtuin-mediated autophagy plays a crucial regulatory role in some cardiovascular diseases, including atherosclerosis, ischemia/reperfusion injury, hypertension, heart failure, diabetic cardiomyopathy, and drug-induced myocardial damage. In this context, we summarize the research advancements pertaining to various Sirtuins involved in autophagy and the molecular mechanisms regulating autophagy. We also elucidate the biological function of Sirtuins across diverse cardiovascular diseases and further discuss the development of novel drugs that regulate Sirtuin-mediated autophagy

Modulating the Graphitic Domains and Pore Structure of Corncob-Derived Hard Carbons by Pyrolysis to Improve Sodium Storage

Biomass-derived hard carbon materials are considered as the most promising anode materials for sodium-ion batteries (SIBs) due to their abundant sources, environmental friendliness, and excellent electrochemical performance. Although much research exists on the effect of pyrolysis temperature on the microstructure of hard carbon materials, there are few reports that focus on the development of pore structure during the pyrolysis process. In this study, corncob is used as the raw material to synthesize hard carbon at a pyrolysis temperature of 1000~1600 °C, and their interrelationationship between pyrolysis temperature, microstructure and sodium storage properties are systematically studied. With the pyrolysis temperature increasing from 1000 °C to 1400 °C, the number of graphite microcrystal layers increases, the long-range order degree rises, and the pore structure shows a larger size and wide distribution. The specific capacity, the initial coulomb efficiency, and the rate performance of hard carbon materials improve simultaneously. However, as the pyrolysis temperature rises further to 1600 °C, the graphite-like layer begins to curl, and the number of graphite microcrystal layers reduces. In return, the electrochemical performance of the hard carbon material decreases. This model of pyrolysis temperatures–microstructure–sodium storage properties will provide a theoretical basis for the research and application of biomass hard carbon materials in SIBs