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Cost and Environmental Assessment of Tool Replacement Strategies Under Imperfect Wear Monitoring in Ti6Al4V Milling
Full text linkpeer reviewedThe policy for the replacement of cutting tools has a direct influence on the risk of producing out-of-tolerances workpieces, but can also avoid excessive consumption of new tools and production interruption. Current industrial practice tries to achieve an economical balance that does not directly incorporate the environmental impact of the policy. This often results in systematic preventive replacement of tools after a safely fixed number of produced workpieces, wasting a portion of the tool’s useful life (at an environmental cost) and increasing the machine’s downtime. In this study, we simulate the production of Ti6Al4V parts under three different tool replacement scenarios: (1) at fixed intervals, (2) using an imperfect cutting tool monitoring system where the tool can only be replaced between the production of two workpieces, and (3) with a cutting tool monitoring system that allows tool replacement every minute during machining. The simulation demonstrates that even with an imperfect monitoring system, condition-based replacement leads to improved economic performance (expressed in EUR) and environmental performance (expressed in kg CO2-eq). In comparison to systematic replacement, the condition monitoring allows reducing the environmental impact up to 8.7% and the cost up to 8.1%.9. Industry, innovation and infrastructure12. Responsible consumption and production13. Climate actio
All that Glitters Attracts
Full text linkpeer reviewedUsing a methodology from experimental finance based on qualitative analysis tools, this article aims at analyzing the potential existence of the ‘all that glitters attracts’ bias in order to explain the behavior of individual investors. For this purpose, we observed the investment strategies and behaviors of eight students in a continuous trading situation over three days. Using a fictional portfolio of 100,000 euros, the participants were given the opportunity to trade shares in companies from the CAC40 index (the 40 largest market capitalizations on the French market). Regarding the size of the companies in the index, we observe a high volume of information disclosed to the markets which could, to a certain extent, complicate the interpretation of the information signals sent. Based on trading journals - and more specifically the number of transactions carried out on specific stocks - we find that participants are strongly focused on companies that are closely followed by financial analysts and receive the most media coverage. To support our findings, we have also used a process of participative observation to collect first-hand experiences from participants during the experiment. The different elements collected suggest that the participants’ decision-making processes were largely influenced by the intensity of the companies’ communication and their presence in the information flows provided by the stock market websites. This conclusion leads us to believe that, in the mind of individual investors, marketing linked to the stock market life of companies seems to prevail over any informational content. In any case, in their decision-making process, the participants clearly selected shares that were in the spotlight, and so, depending on the context of analysis and the investigative tools used, we confirm the presence of an ‘anything that glitters attracts’ bias, a strong focus on available information and some herd effects. The contribution of this article is threefold: the analysis of a bias largely neglected by scientific studies in the financial field, the use of an innovative experimental protocol, and the use of methodological tools that provide an assessment of individuals' personal perceptions
Securidacaxanthone D: a new xanthone with free radical scavenging activity from the roots of Securidaca longepedunculata (Polygalaceae).
Full text linkpeer reviewedA previously unpublished xanthone named securidacaxanthone D (1) and five known analogues: 1,7-dihydroxyxanthone (2), 7-hydroxy-1,2-dimethoxy-xanthone (3), 1,5-dihydroxy-6,7-dimethoxyxanthone (4), 1,7-dihydroxy-3-methoxyxanthone (5), 1,7-dihydroxy-4-methxyxanthone (6) were isolated from the ethyl acetate soluble fraction obtained from the liquid-liquid partition of the crude hydro-ethanolic extract of the roots of Securidaca longipedunculata. Their structures were determined by analysis of 1D -(1H and 13C), 2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (TOF-ESI-MS) and by comparison with reported data. Free radical scavenging activity were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as a free radical. Crude extract, ethyl acetate and n-butanol fractions as well as isolated compounds showed different degrees of free radical scavenging activity. Among the extract and fractions tested, the hydro-ethanolic extract was the most active with an IC50 value of 32 μg/mL. Among the compounds, compound 2 was the most active with an IC50 value of 282 μg/mL
Rapid Dereplication of Trunk Bark Constituents of Croton sylvaticus and Molecular Docking of Terpenoids from Three Congolese Croton Species.
Full text linkpeer reviewedPhytochemical investigation and bioactivity evaluation of terpenoids from the Croton species were conducted. The chemical composition of C. sylvaticus was explored using chemical phytochemical screening techniques and dereplication of 13C NMR data using MixONat software (v. 1.0.1). Natural products with diverse structural features were identified in the dichloromethane extract of trunk bark. These include monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids, along with other minor metabolites, such as steroids, saponins, and fatty acids. Further purification of this extract led to the isolation of three major secondary metabolites, acetyl aleuritolic acid, caryophyllene oxide, and phytol. These secondary metabolites were reported for the first time in C. sylvaticus. The isolated compounds were structurally compared to known anticancer terpenoids previously identified in two other Congolese Croton species. Through molecular docking studies, the predicted binding affinities of the identified compounds were assessed, and possible structure-activity relationships (SAR) were proposed. Two structurally characterized receptors-the human androgen receptor (HAR, PDB ID: 1E3G) and hypoxia-inducible factor 1-alpha (HIF-1α, PDB ID: 3KCX), known for their involvement in cancer-related pathways, were used for molecular docking investigations. Among the tested compounds, 1, 2, 3, and 12 were identified as having strong-to-moderate predicted binding affinities to both protein targets, along with favorable drug-like properties according to the ADMET analysis. This investigation could justify the use of Croton plants in traditional medicine. In addition, our study highlights the potential of the Congolese Croton species as sources of bioactive secondary metabolites
Access to Stock Markets Impact on SMEs Performance
Full text linkpeer reviewedThis paper attempts to examine the listing impact on small and medium enterprises (SMEs) financial performance. Thus, the analysis compares listed with unlisted European SMEs through various metrics such as Solvency, Liquidity, Profit Margin, Return on Asset/ROA, and Return on Equity/ROE over a period of 10 years (from 2014 to 2023). The RStudio program was used to perform an unpaired student t-test to determine the statistically significant difference between the selected performance indicators for both SMEs group. We found that listing has significantly improved SMEs’ ability to meet short and long-term liabilities (Solvency and Liquidity) while profitability (Profit Margin, ROA and ROE) has notably deteriorated
