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- Application of LEAN methodology to support projects improvements in a die casting industryPublication . Sousa, Liliana Marina Ferreira de; Ferreira, Irene Sofia Carvalho; Schillig, RainerThe main goal of this project is to define waste, measure and eliminate it, inherent to the production of aluminium die casting parts on the company Schüle Druckguss in Germany. In order to eliminate waste, a set of improvement projects were carried out focusing on the production in the different halls of the company. For that purpose, Lean thinking and tools were used as supporting methodology. It is important to highlight that these projects include issues like the organization of the workplace, the optimization of the workload for the worker, programing transport routes and minimize inventory of raw material and finish goods. Towards to achieve the previous goals, it was necessary to observe operations and procedures, measure time, detect bottlenecks or critical tasks and test different scenarios, aiming to reduce the most wasteful activities. Referring to the workplace organization, the solution achieved consists on the application of a colored marking system on the floor to define the transport way and the place for the material. Regarding the workload of the worker, it was optimized given the worker, in the new procedure, more tasks, mostly due to the introduction of automation of controlling process. About the routes for the truck coming from the daughter company in Slovakia, it was changed and some wasteful activities reduced, obtaining a minimization of 15% of the time spent on these activities per day. Note that human and material resources were also saved with the new proposal. Furthermore, the necessary quantity of inventory referent to one product was calculated the economic quantity order and minimized costs in 34%. For the finish goods it was proposed a new layout for the boxes, in order to be transported more quantities, according with customers demand. Finally, it was studied a product and its variations, that is die casted on the daughter company in Slovakia and machined in Germany, in order to change its production to a continuous line in Germany. Thus, it was included on the Die Casting Island (DCI), three external processes, minimizing the time in transportation and using fewer workers than the actual situation. The current project is focused on continuous improvement, providing a low cost approach and performs the main goal which is to achieve the best practices within the organization.
- An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responsesPublication . Costa, Pedro M.; Pinto, Miguel; Vicente, Ana M.; Gonçalves, Cátia; Rodrigo, Ana P.; Louro, Henriqueta; Costa, Maria H.; Caeiro, Sandra; Silva, Maria J.The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments.