Technical University of Berlin

About: Technical University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Laser & Catalysis. The organization has 27292 authors who have published 59342 publications receiving 1414623 citations. The organization is also known as: Technische Universität Berlin & TU Berlin.

Laplacian mesh optimization

Abstract: We introduce a framework for triangle shape optimization and feature preserving smoothing of triangular meshes that is guided by the vertex Laplacians, specifically, the uniformly weighted Laplacian and the discrete mean curvature normal. Vertices are relocated so that they approximate prescribed Laplacians and positions in a weighted least-squares sense; the resulting linear system leads to an efficient, non-iterative solution. We provide different weighting schemes and demonstrate the effectiveness of the framework on a number of detailed and highly irregular meshes; our technique successfully improves the quality of the triangulation while remaining faithful to the original surface geometry, and it is also capable of smoothing the surface while preserving geometric features.

Preservation of liquid foods by high intensity pulsed electric fields-basic concepts for process design

Abstract: In excess of a critical transmembrane potential ΔϕM of −1 V produced by high intensity pulsed electric fields a rapid electrical breakdown and local conformational changes of cell membranes occur which result in a drastic increase in permeability and an equilibration of the electrochemical and electrical potential differences of the cell plasma and the extracellular medium. As irreverible membrane permeabilization impairs most vital physiological control systems, high intensity pulsed electric fields may be applied as a highly effective process for the microbial decontamination of liquid foods. The efficiency of the treatment is largely influenced by the inherent properties of the foods and of the spoiling microorganisms. In addition a number of technical limitations have to be considered. In this review an approach is presented which reduces the diversity of parameters that affect microbial inactivation during pulsed power treatment. In particular, the required total specific energy input is discussed.

Separation of Azeotropic Mixtures Using Hyperbranched Polymers or Ionic Liquids

Abstract: In this work the suitability of selected commercially available hyperbranched polymers and ionic liquids as entrainers for the extractive distillation and as extraction solvents for the liquid–liquid extraction is investigated. Based on thermodynamic studies on the influence of hyperbranched polymers and ionic liquids on the vapor–liquid and liquid–liquid equilibrium of the azeotropic ethanol–water and THF–water systems, process simulations are carried out, which allow evaluating the potential of hyperbranched polymers and ionic liquids as selective components for the mentioned applications in terms of feasibility and energetic efficiency. Both hyperbranched polymers and ionic liquids break a variety of azeotropic systems. Since their selectivity, capacity, viscosity, and thermal stability can be customized, they appear superior to many conventional entrainers and extraction solvents. For the ethanol–water separation, the nonvolatile substances hyperbranched polyglycerol and [EMIM][BF4] show a remarkable entrainer performance and therefore enable extractive distillation processes, which require less energy than the conventional process using 1,2-ethanediol as an entrainer. Evaluation of a new THF–water separation process indicates the competitiveness of the suggested process and a considerable potential of using hyperbranched polymers as extraction solvents. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2439 –2454, 2004