Confined fractal patterns in gelatin

[[abstract]]Fractal patterns are commonly found during the re-crystallization process of over-saturated solution. In this work, the authors initially choose the gelatin aqueous solution, of high weight percentage of 18.2-27.3 wt %, dissolved with excess amount (9 wt %) of a photo-sensitizer agent potassium dichromate (K2Cr2O7) and sodium chloride (NaCl) to generate the tree-like, dendrite, fractal micro structures with the feature size of 5-40 μm. They also tried to make the fractal patterns uniformly to some extent according to Feynman's confinement statement. The smaller field for growing fractal gelatin has the survival percentage of 80 %, over the survival percentage of 55 % for the 5000 μm larger case. These fractal patterns are going to develop the application to the fabrication of new chaotic mixers.[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20110220~20110223[[iscallforpapers]]Y[[conferencelocation]]Kaohsiung, Taiwa

Image-Based Three-Dimensional Analysis to Characterize the Texture of Porous Scaffolds

The aim of the present study is to characterize the microstructure of composite scaffolds for bone tissue regeneration containing different ratios of chitosan/gelatin blend and bioactive glasses. Starting from realistic 3D models of the scaffolds reconstructed from micro-CT images, the level of heterogeneity of scaffold architecture is evaluated performing a lacunarity analysis. The results demonstrate that the presence of the bioactive glass component affects not only macroscopic features such as porosity, but mainly scaffold microarchitecture giving rise to structural heterogeneity, which could have an impact on the local cell-scaffold interaction and scaffold performances. The adopted approach allows to investigate the scale-dependent pore distribution within the scaffold and the related structural heterogeneity features, providing a comprehensive characterization of the scaffold texture

Blood vessels by fractal gelatin

[[abstract]]n this study the authors developed a novel gelatin patterning technique applied to making blood vessel with fractal dendrite configuration. Such a chaotic tree-like pattern has been obtained through precipitating among the gelatin matrix which is spun coating on a glass substrate at room temperature. The weight percentage of the original gelatin solution is over-saturated. As the temperature decrease, the gelatin crystallizes and forms a natural fractal pattern in the thin film. The process parameters are changed and the hydraulic diameters of the fractal patterns are verified from 0.1 μm to 23 μm. Finally the authors used the biocompatible PDMS making blood vessel like capillary channels by the de-molding process of the soft lithography. The filling test of the PDMS fractal channel chip is done accordingly.[[conferencetype]]國際[[conferencedate]]20120305~20120308[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Kyoto, Japa

Fractal grooves applied to passive micro-mixers

[[abstract]]The purpose of the present work is to study on the application of a navel fractal pattern to passives micro-mixers. The SU-8 soft lithography is used to transfer the fractal grooves and the micro channel to PDMS mold on a glass. The authors also used numerical software Fluent to simulate the flow fields of the new passive micro-mixers. The 3 kinds of fractal configurations, three flow conditions (Re=0.64, 6.4, and 64) have been compared with the experimental mixing indices. The simulation results show that the novel fractal pattern do create lateral mass transport to improve mixing. With the same fractal patterns, the lower Reynolds number flow (0.64) has the higher mixing index. The branch with fractal patterns for two times (type III) is also better than other cases with high mixing performance.[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20110220~20110223[[iscallforpapers]]Y[[conferencelocation]]Kaohsiung, Taiwa

Spatially Resolved Monitoring of Drying of Hierarchical Porous Organic Networks

Evaporation kinetics of water confined in hierarchal polymeric porous media is studied by low field nuclear magnetic resonance (NMR). Systems synthesized with various degrees of cross-linker density render networks with similar pore sizes but different response when soaked with water. Polymeric networks with low percentage of cross-linker can undergo swelling, which affects the porosity as well as the drying kinetics. The drying process is monitored macroscopically by single-sided NMR, with spatial resolution of 100 μm, while microscopic information is obtained by measurements of spin?spin relaxation times (T2). Transition from a funicular to a pendular regime, where hydraulic connectivity is lost and the capillary flow cannot compensate for the surface evaporation, can be observed from inspection of the water content in different sample layers. Relaxation measurements indicate that even when the larger pore structures are depleted of water, capillary flow occurs through smaller voids.Fil: Velasco, Manuel Isaac. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Silletta, Emilia Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo En Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo En Ingeniería de Procesos y Química Aplicada.; ArgentinaFil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Stapf, Siegfried. Ilmenau University of Technology; AlemaniaFil: Monti, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Mattea, Carlos. Ilmenau University of Technology; AlemaniaFil: Acosta, Rodolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

Functional Biodegradable Nanocomposites

Concern around environmental issues facing society has grown significantly in recent years. Reduction in damages resulting from both industrial and domestic waste has become a key topic as a means to address environmental problems and the exhaustion of natural resources. Likewise, the use of materials of polymeric origin in applications such as tissue regeneration, controlled release of medicines, packaging, soil remediation, etc., makes the development of materials biodegradable in biological media increasingly important. Recently, significant progress has been achieved in the creation of biodegradable polymeric formulations with functionalities similar to those of non-biodegradable polymers, both of natural and of synthetic origin, extending their applicability to fields such as food packaging, electronics, production of health-related materials, agriculture, etc. In this context, biodegradable nanocomposites offer new and exciting possibilities. This book deals with the development of functional polymer nanocomposites that can undergo biodegradation in different media, including biological systems, soils, landfills, etc. Original and review articles covering aspects of polymer science and technology, such as synthesis, processing, characterization, properties, and applications of functional biodegradable nanocomposites for different applications, are included in this book

Fragmentation of explosively metastable glass [post-print]

An unusual form of glass with bulbous head and thin tail, known as Rupert\u27s drops, can withstand high impact or pressure applied to the head, but explodes instantly into small particles when the tail is broken. The mechanism is not well understood. To examine this, we performed macro- and microstatistical analyses of a sample of 500 g of fragments of exploded Rupert\u27s drops to determine the mass and particle distributions and associated fractal dimensions. To our knowledge, this is the first such statistical study of the fragmentation of a metastable material with large internal energy. The resulting fractal dimensionD = 1.06 ± 0.09, derived from the scaling region of the mass and particle distribution functions approximated by power laws, differs from fractal dimensions (usually ≥2) previously reported for many brittle materials. The observed distribution functions place constraints on proposed mechanisms for the explosive disintegration of the drops and presumably other physical systems characterized by high compressive stress at the surface and tensile stress within the core