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The economic and environmental effect of remanufacturing authorization in the fuzzy environment
No full textRemanufacturing has attracted considerable attention because it significantly contributes to a sustainable supply chain where used parts/products can be recycled to reduce waste. Faced with the rise of the remanufacturing business, many original equipment manufacturers (OEMs) choose to authorize independent remanufacturers (IRs) for profit. In this paper, we consider a sustainable supply chain consisting of an OEM and an IR in a fuzzy environment where production cost and market demand are uncertain to study whether such an authorization decision would benefit both the economy and the environment. An unauthorized model (Nash game model) and two authorized models (Cooperative game and Stackelberg game models) are developed. Our results show that the cooperation between the OEM and the IR increases the selling price of the product, and therefore encourages authorization financially. However, a leader position of the OEM (i.e., in the Stackelberg game) helps achieve a win–win situation where profit maximization also improves the environment. Furthermore, our analysis illustrates that considering a fuzzy environment will boost the chances of authorization and help achieve a win–win situation
Robust optimization for supply chain with routing problem: a learning-based approach
No full textEffective supply chain management is crucial for businesses to remain competitive in today’s dynamic market. Despite extensive research, there is a lack of integrated approaches that simultaneously address resource allocation, routing, and delivery scheduling under uncertain conditions. This study develops a hybrid framework that combines robust optimization, simulated annealing, and reinforcement learning to enhance supply chain operations in complex networks involving fixed suppliers, distribution centers, and customers. Empirical results from rigorous testing demonstrate significant efficiency improvements and adaptability across diverse scenarios. A real-world case study from the logistics sector highlights the practical benefits, achieving notable cost savings and operational robustness. Sensitivity analysis further underscores the model’s capability to adapt to parameter variations. These findings emphasize the value of incorporating learning-based strategies into supply chain optimization, offering a powerful tool for organizations to address uncertainty and enhance decision-making efficiency
Influence of built environment on transit trips with different purposes: A case study of the central urban area in Jinan
No full textA well-designed built environment promotes transit use, public health, and quality of life. This study conducted an empirical analysis of the central urban area of Jinan, considering four trip purposes: commuting, shopping, schooling, and leisure. The analysis employed the “5Ds” framework of built environment indicators in combination with binary and multinomial logistic regression models. Findings revealed substantial variation in how built environment factors shape different types of transit trips. Specifically, shopping trips were strongly associated with multifunctional commercial centers featuring high metro accessibility; commuting displayed a “U-shaped” dual-center pattern, with flows concentrated in both the urban core and suburban industrial parks; leisure travel often originated in mixed-use residential neighborhoods and extended toward open spaces; and school trips were influenced mainly by regular bus routes connecting central residential districts to suburban schools. Based on these insights, the study recommends implementing a purpose-oriented TOD model. Key priorities include strengthening the polycentric spatial structure, improving the integration of blue-green infrastructure with the public transit system, and aligning school district planning more closely with transit networks. These strategies provide theoretical guidance and practical pathways to advance “public transit priority” policies and sustainable mobility planning in Jinan and other comparable urban contexts
Application of Magnetic Coagulation High-Efficiency Precipitation Process in the Advanced Treatment Section of Sewage Treatment Plants
No full textThe magnetic coagulation high-efficiency sedimentation technology organically combines flocculation and magnetic separation, fully utilizing the magnetic cohesion and the bridging effect of flocculants to form magnetic flocs for accelerated sedimentation. Taking the second phase of Chengnan Wastewater Treatment Plant as an example, the application of magnetic coagulation high-efficiency sedimentation process in the project is studied. Hydraulic models and hydraulic velocity vector models of the mixing agitator and coagulation reaction agitator are established. The impeller type and speed of the agitator are calculated based on the tank type and chemical properties. CFD simulation is used to study the effect of adding magnetic powder to wastewater
Study on the Renewal Mode of Modern Residential Architectural Heritage under the Perspective of “Conjunctive Ecological Theory”-Taking Ancient City of Suzhou as an Example
No full textThis study focuses on modern residential buildings located in the central area of Suzhou. Based on a systematic review of their historical evolution and an in-depth assessment of their current preservation and utilization status, the research identifies the common issues and key characteristics of these urban dwellings. It further categorizes both tangible and intangible cultural heritage resources associated with the residential environment. Twelve representative residential buildings, each preservation challenges, are selected for detailed analysis. Guided by principles of integrated urban renewal, the study proposes targeted regeneration strategies emphasizing the synergy between historical legacy and contemporary culture, the coexistence of productive and residential functions, the spatial integration of old and new structures, and the social inclusion of local and migrant populations. These strategies incorporate technical approaches such as structural reinforcement, adaptive reuse, spatial reconfiguration, and community-oriented design, aiming to promote the sustainable development and culturally sensitive revitalization of Suzhou’s modern residential heritage
Analysis of Bioactive Compounds and DPPH Radical Inhibition Activity of Hydroethanolic Extracts from
No full textMucuna pruriens is a medicinal plant known to contain various bioactive compounds, including L-DOPA, alkaloids, phenolics, and tannins, with potential as a natural antioxidant. This study aimed to evaluate the characteristics of Mucuna pruriens seed simplicia and its hydroethanolic extract, identify its secondary metabolites, and determine its antioxidant activity. Simplicia were characterized through moisture and ash content analysis, and extraction was carried out using maceration with hydroethanol (1:1) solvent. The results showed a moisture content of 2% and an ash content of 2.1%, meeting the standards of the Indonesian Herbal Pharmacopoeia. The extract yield was 17.6%, indicating good extraction efficiency. Phytochemical screening revealed the presence of alkaloids, phenolics, tannins, and triterpenoids. Antioxidant activity was assessed using the DPPH method, yielding an IC50 value of 2.18 ppm, indicating a powerful antioxidant category. These findings suggest that the hydroethanolic extract of Mucuna pruriens seeds has high potential as a natural antioxidant source for health and cosmetic applications
Preliminary Study on the Toxic Effects of Polystyrene Microplastics in Human Colorectal Cells
No full textAccording to this rapid urbanization background, the widespread presence of microplastics in the environment, caused by plastic pollution and poor waste management, poses a huge threat to public health. This research aims to evaluate the colorectal health risk associated with microplastics and provides data for managing urban water and food security. We have evaluated the toxic impact of different sizes (80 nm and 500 nm) of polystyrene microplastics (PS-MPs) on human colorectal cells (NCM460). Analyses were conducted to assess changes in cell viability, cell cycle, and apoptotic response after exposure to PS-MPs of varying particle sizes and concentrations. Our results revealed that 80 nm and 500 nm PS-MPs significantly reduced cell viability, induced cell apoptosis, and prolonged the time that cells stay in the S-phase. These results demonstrated a size-and concentration-dependent toxic effect. Therefore, this investigation provides experimental evidence for evaluating the intestinal health risks of microplastics, and calls for the optimization of the water treatment process in the field of environmental engineering to achieve targeted removal of these high-risk microplastics
LLM-Enhanced Theme Identification and Classification of Urban Housing Policy Texts
No full textUrban housing development has always been a key area of focus in urban studies. Accurate understanding of housing policy texts is of great significance for the sustainable development of urban housing. Different from traditional text analysis methods, we have proposed a machine learning (ML) framework driven by a large language models (LLMs) to quickly and accurately extract policy text themes and classify them. We used Mengzi-BERT-Base (MBB) for semantic encoding of policy documents, used GPT-4o to extract policy keywords and grasp the macro logic, and finally integrated the features of the two using a random forest model to output classification results. The results show that this framework divides housing policy texts into 4 core themes, with an overall accuracy rate of 70.25%, and the accuracy rate of individual themes is 75.56%, indicating that this framework has certain application value in urban policy text analysis
Study on pollutant emission characteristics of sludge combustion in municipal wastewater treatment plants under oxygen-enriched conditions
No full textOxygen-enriched combustion technology, as an efficient and clean combustion technology, shows great potential in the field of sludge disposal by using a high concentration of oxygen (>21%) instead of air as a combustion agent. Firstly, this paper investigates the differences in pollutant emission characteristics between sludge under oxygen-enriched combustion and air combustion conditions. The experimental results showed that the generation of CO was 887 ppm under oxygen-enriched combustion, which was higher than that of 301 ppm under air combustion, and the generation of NO and SO2 were 247 ppm and 71 ppm, which were lower than that of 291 ppm and 100 ppm under air combustion, respectively. Secondly, the effects of different oxygen concentrations on the pollutant emission characteristics of sludge under oxygen-enriched combustion were investigated in this paper. Secondly, the article further investigated the effects of different oxygen concentrations on the emission characteristics of pollutants during oxygen-enriched combustion. The results showed that under the oxygen-enriched combustion condition, the generation of CO showed a tendency of decreasing and then increasing. The lowest CO generation was 631 ppm at 50% oxygen concentration, while the NO and SO2 generation showed a gradual increase at 50% oxygen concentration, with 283 ppm and 79 ppm, respectively; however, in the range of 21% to 50% oxygen concentration, the growth of NO and SO2 generation was significantly lower than that in the range of 50% to 100% oxygen concentration. The growth trend in the range of 50% to 100% oxygen concentration is significantly lower. In summary, oxygen-enriched combustion in an atmosphere with 50 per cent oxygen concentration is more conducive to suppressing the generation of combustion pollutants
The changes in the circumstances and cultural adaptation of the indigenous people in the suburbs of Beijing during the process of urban expansion-Multidimensional Analysis Based on Online ethnography
No full textThis study focuses on the marginalization of indigenous people in the suburbs of Beijing during the process of urban expansion and uses ecological anthropology theory and online ethnographic methods to analyze the relevant content on online platforms such as Douyin and Xiaohongshu. The study found that the ring line hierarchy led to the absence of spatial justice, and demolition compensation ignored multiple losses of indigenous people. The mainstream economic rational discourse in the digital age suppresses the emotional demands of indigenous people, and although indigenous people try to resist digitally, it is difficult to reverse the disadvantage. Cultural identity dies in social transformation, and indigenous people face social adaptation difficulties. This study reveals the underlying mechanisms of indigenous marginalization and provides a theoretical reference for urban renewal policy-making in order to promote a balance between urban development and the protection of indigenous rights