Jianfeng Li

Bio: Jianfeng Li is an academic researcher from Shandong University. The author has contributed to research in topics: Machining & Surface roughness. The author has an hindex of 24, co-authored 202 publications receiving 1971 citations. Previous affiliations of Jianfeng Li include Chinese Ministry of Education.

A review on the recent development of incremental sheet-forming process

Abstract: This paper presents a detailed literature review on the current research of incremental sheet forming relating to deformation mechanism, modelling techniques, forming force prediction and process investigations. First, a review of the fundamental deformation mechanism and formability in incremental sheet forming (ISF) is provided. Subsequently, the modelling techniques for ISF are reviewed and categorised into two approaches: analytical modelling and finite element modelling. Special interest is given to a critical review regarding the forming forces analysis and prediction during the process. Then, previous publications related to geometric accuracy, surface finish and forming efficiency in ISF are reviewed. Finally, several potential hybrid incremental sheet-forming strategies are discussed. This leads to a statement of conclusion which may act as an inspiration and reference for the researcher.

Evaluation of cutting force and cutting temperature in milling carbon fiber-reinforced polymer composites

Abstract: The cutting temperature and cutting force are some of the main factors that influence the surface quality of carbon fiber-reinforced polymer (CFRP). However, few investigations have been done on cutting temperature because it is difficult to capture the dynamic response of the temperature measurement system. Degradation of resin will occur within the machined surface or surface layer as the temperature exceeds the glass-transition temperature of the resin matrix. In this research, the relationship between cutting parameters and cutting temperature, cutting force were developed by response surface methodology (RSM). The experiments were designed using the tool-workpiece thermocouple technique. Taking into consideration the effect of the glass-transition temperature, the influence of cutting force and cutting temperature on surface quality of CFRP was analyzed. Analysis results showed that Spindle speed is the key parameter which influenced the cutting temperature while feed rate is the key parameter which influenced the cutting force in milling of CFRP. When the cutting temperature exceeds the glass-transition temperature (T g), the matrix cannot provide enough support to the fibers, and the machining quality of composite material is poor.

Finite element simulation and experimental investigation on the residual stress-related monolithic component deformation

Abstract: The principal influence factors on the monolithic component deformation were investigated by finite element simulation simulation and experiment. Initial residual stress of the blank, machining-induced residual stress, and coupling action of these two effect factors were considered. To study the effect of blank initial residual stress on component deformation, chemical milling was used to remove the machining-induced residual stress on the machined surface of the components. The research results show that the initial residual stress in the blank was the main factor of deformation for three-frame monolithic beam, and the coupling action of the initial residual stress and machining-induced residual stresses aggravated the deformation. The deformation caused by machining residual stress accounted for about 10 % of the total deformation of the component, and the deformation caused by the blank initial residual stress accounted for 90 % of the total deformation of the component. The finite element simulation results were compared with experimental results and found to be in good agreement.

Identifying best existing practice for characterization modeling in life cycle impact assessment

Abstract: Life cycle impact assessment (LCIA) is a field of active development. The last decade has seen prolific publication of new impact assessment methods covering many different impact categories and providing characterization factors that often deviate from each other for the same substance and impact. The LCA standard ISO 14044 is rather general and unspecific in its requirements and offers little help to the LCA practitioner who needs to make a choice. With the aim to identify the best among existing characterization models and provide recommendations to the LCA practitioner, a study was performed for the Joint Research Centre of the European Commission (JRC). Existing LCIA methods were collected and their individual characterization models identified at both midpoint and endpoint levels and supplemented with other environmental models of potential use for LCIA. No new developments of characterization models or factors were done in the project. From a total of 156 models, 91 were short listed as possible candidates for a recommendation within their impact category. Criteria were developed for analyzing the models within each impact category. The criteria addressed both scientific qualities and stakeholder acceptance. The criteria were reviewed by external experts and stakeholders and applied in a comprehensive analysis of the short-listed characterization models (the total number of criteria varied between 35 and 50 per impact category). For each impact category, the analysis concluded with identification of the best among the existing characterization models. If the identified model was of sufficient quality, it was recommended by the JRC. Analysis and recommendation process involved hearing of both scientific experts and stakeholders. Recommendations were developed for 14 impact categories at midpoint level, and among these recommendations, three were classified as “satisfactory” while ten were “in need of some improvements” and one was so weak that it has “to be applied with caution.” For some of the impact categories, the classification of the recommended model varied with the type of substance. At endpoint level, recommendations were only found relevant for three impact categories. For the rest, the quality of the existing methods was too weak, and the methods that came out best in the analysis were classified as “interim,” i.e., not recommended by the JRC but suitable to provide an initial basis for further development. The level of characterization modeling at midpoint level has improved considerably over the last decade and now also considers important aspects like geographical differentiation and combination of midpoint and endpoint characterization, although the latter is in clear need for further development. With the realization of the potential importance of geographical differentiation comes the need for characterization models that are able to produce characterization factors that are representative for different continents and still support aggregation of impact scores over the whole life cycle. For the impact categories human toxicity and ecotoxicity, we are now able to recommend a model, but the number of chemical substances in common use is so high that there is a need to address the substance data shortage and calculate characterization factors for many new substances. Another unresolved issue is the need for quantitative information about the uncertainties that accompany the characterization factors. This is still only adequately addressed for one or two impact categories at midpoint, and this should be a focus point in future research. The dynamic character of LCIA research means that what is best practice will change quickly in time. The characterization methods presented in this paper represent what was best practice in 2008–2009.

Molecular classification and novel targets in hepatocellular carcinoma: recent advancements.

Abstract: Hepatocellular carcinoma (HCC) is one of most lethal cancers worldwide. Strategic decisions for the advancement of molecular therapies in this neoplasm require a clear understanding of its molecular classification. Studies indicate aberrant activation of signaling pathways involved in cellular proliferation (e.g., epidermal growth factor and RAS/mitogen-activated protein kinase pathways), survival (e.g., Akt/mechanistic target of rapamycin pathway), differentiation (e.g., Wnt and Hedgehog pathways), and angiogenesis (e.g., vascular endothelial growth factor and platelet-derived growth factor), which is heterogeneously presented in each tumor. Integrative analysis of accumulated genomic datasets has revealed a global scheme of molecular classification of HCC tumors observed across diverse etiologic factors and geographic locations. Such a framework will allow systematic understanding of the frequently co-occurring molecular aberrations to design treatment strategy for each specific subclass of tumors. Accompanied by a growing number of clinical trials of molecular targeted drugs, diagnostic and prognostic biomarker development will be facilitated with special attention on study design and with new assay technologies specialized for archived fixed tissues. A new class of genomic information, microRNA dysregulation and epigenetic alterations, will provide insight for more precise understanding of disease mechanism and expand the opportunity of biomarker/therapeutic target discovery. These efforts will eventually enable personalized management of HCC.

A review of energy efficiency in ports: Operational strategies, technologies and energy management systems

Abstract: Many ports and terminals endeavor to enhance energy efficiency as energy prices have increased through years and climate change mitigation is a key target for the port industry. Stricter environmental regulations are adopted by authorities to limit pollutants and GHG emissions arising from energy consumption. Increasingly, port operational strategies and energy usage patterns are under scrutiny. To ingrain sustainability and environmental protection of ports, the use of innovative technology appears as a critical conduit in achieving a transition from a carbon-intensive port industry (dependent on fossil fuels) to a low-carbon port model by harnessing renewable energy, alternative fuels (e.g. LNG, hydrogen, biofuel), smarter power distribution systems, energy consumption measurement systems. In this context, this paper conducts a systematic literature review to analyze operational strategies (e.g. peak shaving, operations optimization), technology usage (e.g. electrification of equipment, cold-ironing, energy storage systems), renewable energy, alternative fuels and energy management systems (e.g. smart grid with renewable energy) for improving the energy efficiency and environmental performance of ports and terminals. Research gaps and future research directions are identified. Analysis shows that there is a great potential for ports to achieve further energy efficiency and researchers have many impactful research opportunities.