Just Glass: Development of a Topology Optimization Algorithm for a Mass-Optimized Cast Glass Component.

This thesis continues the investigation in the direction of exploring the potential regarding the use of Topology Optimization techniques for the design of cast glass structures. Previous theses in TU Delft have underlined the large potential for the design of these megaliths, but at the same time they have also underlined the strong limitations that derive from the use of commercial software as the tool for it.The limitations are directly related to the brittle nature of glass which results in significantly different behavior regarding its maximum tensile and compressive allowable limits. This renders fundamental to be able to evaluate both of these criteria during the optimization process. If this is not possible, as it was the case in the previous theses, a secondary (post-processing) phase should be integrated in the process in order to alleviate the peak stresses that may occur in the structure. This increases significantly the time and effort needed for the design and, therefore, it was underlined as an issue to be tackled in further exploration. This thesis aspires to address this problem with the creation of a customized optimization tool that takes all the structural constraints into consideration and, additionally, integrates the criteria specifically related to the glass manufacturing process, such as the overall annealing time needed. The tool is created in Matlab with the use of Finite Element Method equations in order to develop the structural model. The results of the structural analysis were validated through comparison with results obtained through ANSYS.The literature review covers a wide scope of topics. Firstly, the glass properties and the casting process are investigated in order to properly indicate the criteria and constraints that arise in every phase. The second part refers to topology optimization. A comparative review of the different algorithmic methodologies is realized and SIMP is selected as the most appropriate for the project. Additionally, the different categories of formulation for the optimization problem – stress, compliance and volume based – are discussed in order to select the appropriate objective and constraints. At the same time, a review of the previous theses is realized in order to indicate which method was used in every case and how the constraints were integrated in the process every time.In the end two different algorithms are developed based on two different problem formulations; one with compliance objective and a second one with volume objective. The aim is to investigate if the volume objective optimization can be a robust alternative to the classical compliance approach leading to more lightweight structures which at the same time fulfill the criteria regarding their feasibility to be manufactured.Firstly, the performance of the algorithm in relation to each objective and constraint individually is evaluated though application in a smaller scale benchmark problem. The results showed that all the setups work and, therefore, they can be used for the final design experiments. However, it also indicated that some constraints, such as stress, cannot be applied individually but they always have to be combined with another constraint that guides the optimization in order to lead in a reasonable result. Afterwards, a combination of objective and constraints for each of the two aforementioned formulations – compliance and volume - is tested and applied in the case study example which refers to a slab that serves as a small pedestrian bridge inside the British Museum.The results validate the estimation that a volume-based problem formulation can offer a robust result which resembles the result obtained from the traditional compliance-based formulation. Moreover, the result in the volume-based case is clearer and sharper and for this reason it was selected in the end for implementation in the final design. The formulation is then used in combination with different glass types, boundary conditions and design domain in order to conclude to the final shape of the slab.Architecture, Urbanism and Building Sciences | Building Technology | Sustainable Desig

Combined effects of atorvastatin and metformin on glucose-induced variations of inflammatory process in patients with diabetes mellitus

Background: Statin treatment improves survival in patients with atherosclerosis, but their effect on the glucose-induced variations of inflammatory markers, is unknown. We examined the effect of combined therapy with atorvastatin and metformin on glucose-induced variations of inflammatory molecules in patients with newly diagnosed diabetes mellitus type 2 (DM). Methods: Thirty five subjects with newly diagnosed DM were randomized to receive metformin 850 mg/d (M, n=17) or metformin 850 mg/d + atorvastatin 10 mg (n=18). All subjects underwent glucose loading (75 g oral glucose) at baseline and after 12 weeks of treatment. Blood samples were obtained at baseline and 3 h post-loading, while serum tumor necrosis factor alpha (TNF-alpha) levels were determined at baseline and at 3 h. Results: Serum TNF-alpha remained unchanged in metformin at baseline (1.36 +/- 0.18 to 1.47 +/- 0.21 pg/ml p=NS) and after treatment (1.44 +/- 0.71 to 1.31 +/- 0.17 pg/ml, p=NS), while it was reduced in metformin + atorvastatin (2.3 +/- 0.3 to 2.0 +/- 0.4 pg/ml, p=NS at baseline and 1.80 +/- 0.2 to 1.65 +/- 0.2 pg/ml, p=0.03 after treatment). Conclusions: Interestingly, the combination of metformin and atorvastatin partly prevents the glucose-loading induced elevation of glucose levels (at 1 h), suggesting a better response to glucose intake than monotherapy with metformin. In addition, combined treatment with atorvastatin and metformin reduces the post-glucose loading levels of TNF-alpha compared to metformin monotherapy. (C) 2009 Elsevier Ireland Ltd. All rights reserved

Current real-life use of vasopressors and inotropes in cardiogenic shock - adrenaline use is associated with excess organ injury and mortality

Vasopressors and inotropes remain a cornerstone in stabilization of the severely impaired hemodynamics and cardiac output in cardiogenic shock (CS). The aim of this study was to analyze current real-life use of these medications, and their impact on outcome and on changes in cardiac and renal biomarkers over time in CS. The multinational CardShock study prospectively enrolled 219 patients with CS. The use of vasopressors and inotropes was analyzed in relation to the primary outcome, i.e., 90-day mortality, with propensity score methods in 216 patients with follow-up data available. Changes in cardiac and renal biomarkers over time until 96 hours from baseline were analyzed with linear mixed modeling. Patients were 67 (SD 12) years old, 26 % were women, and 28 % had been resuscitated from cardiac arrest prior to inclusion. On average, systolic blood pressure was 78 (14) and mean arterial pressure 57 (11) mmHg at detection of shock. 90-day mortality was 41 %. Vasopressors and/or inotropes were administered to 94 % of patients and initiated principally within the first 24 hours. Noradrenaline and adrenaline were given to 75 % and 21 % of patients, and 30 % received several vasopressors. In multivariable logistic regression, only adrenaline (21 %) was independently associated with increased 90-day mortality (OR 5.2, 95 % CI 1.88, 14.7, p = 0.002). The result was independent of prior cardiac arrest (39 % of patients treated with adrenaline), and the association remained in propensity-score-adjusted analysis among vasopressor-treated patients (OR 3.0, 95 % CI 1.3, 7.2, p = 0.013); this was further confirmed by propensity-score-matched analysis. Adrenaline was also associated, independent of prior cardiac arrest, with marked worsening of cardiac and renal biomarkers during the first days. Dobutamine and levosimendan were the most commonly used inotropes (49 % and 24 %). There were no differences in mortality, whether noradrenaline was combined with dobutamine or levosimendan. Among vasopressors and inotropes, adrenaline was independently associated with 90-day mortality in CS. Moreover, adrenaline use was associated with marked worsening in cardiac and renal biomarkers. The combined use of noradrenaline with either dobutamine or levosimendan appeared prognostically similar