904 resultados para Micro-aeration
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Tesi sulla creazione di un'app che adotta i princìpi di gamification e micro-learning
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Nella tesi viene presentata una introduzione generale all'Internet of Things, gli utilizzi che ne vengono fatti attualmente e le eventuali modifiche che verranno apportate in futuro, inoltre vengono presentati i problemi che ne derivano e le soluzioni che attualmente risolvono questi problemi. E' presente una introduzione al protocollo presentato da IBM MQTT che attualmente rappresenta uno standard in questo campo. In seguito vengono mostrati i requisiti e le fasi di progettazione di un sistema domotico, quali sono i suoi principali utilizzi quali i vantaggi e i suoi svantaggi. E' presente una introduzione ai dispositivi maggiormente usati per la realizzazione di sistemi del genere, con le loro caratteristiche, in particolare di dispositivi Arduino e Raspberry Pi. Viene mostrato l'uso del protocollo mqtt per la comunicazione tra dispositivi Raspberry Pi e client Android. In fine viene mostrata una realizzazione di un sistema di domotica attraverso l'uso di questo protocollo.
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Caratterizzazione di un biomateriale a base di fitocomplessi, contenente ossalato di potassio, progettato per il trattamento dell'ipersensibilità dentinale.
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Introduzione alla tecnologia PCB. Introduzione software design Circuit Maker Conversione circuito per micro-potenze con CircuitMaker
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Lung macrophages, that is, the intravascular, interstitial, pleural, and surface macrophages, are part of the mononuclear phagocyte system. They are derived from the hematopoietic stem cell in the bone marrow with the monocytes as their putative precursors. Macrophages residing on the inner surfaces of the lungs and immersed within the lung lining layer, that is, the alveolar and the airway macrophages, are constantly exposed to the environment; it is those cells that are recognized as first line of cellular host defense.
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The interest in automatic volume meshing for finite element analysis (FEA) has grown more since the appearance of microfocus CT (μCT), due to its high resolution, which allows for the assessment of mechanical behaviour at a high precision. Nevertheless, the basic meshing approach of generating one hexahedron per voxel produces jagged edges. To prevent this effect, smoothing algorithms have been introduced to enhance the topology of the mesh. However, whether smoothing also improves the accuracy of voxel-based meshes in clinical applications is still under question. There is a trade-off between smoothing and quality of elements in the mesh. Distorted elements may be produced by excessive smoothing and reduce accuracy of the mesh. In the present work, influence of smoothing on the accuracy of voxel-based meshes in micro-FE was assessed. An accurate 3D model of a trabecular structure with known apparent mechanical properties was used as a reference model. Virtual CT scans of this reference model (with resolutions of 16, 32 and 64 μm) were then created and used to build voxel-based meshes of the microarchitecture. Effects of smoothing on the apparent mechanical properties of the voxel-based meshes as compared to the reference model were evaluated. Apparent Young’s moduli of the smooth voxel-based mesh were significantly closer to those of the reference model for the 16 and 32 μm resolutions. Improvements were not significant for the 64 μm, due to loss of trabecular connectivity in the model. This study shows that smoothing offers a real benefit to voxel-based meshes used in micro-FE. It might also broaden voxel-based meshing to other biomechanical domains where it was not used previously due to lack of accuracy. As an example, this work will be used in the framework of the European project ContraCancrum, which aims at providing a patient-specific simulation of tumour development in brain and lungs for oncologists. For this type of clinical application, such a fast, automatic, and accurate generation of the mesh is of great benefit.
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The Gracias Laboratory at Johns Hopkins University has developed microgrippers which utilize chemically-actuated joints to be used in micro-surgery. These grippers, however, take up to thirty minutes to close fully when activated biochemicals in the human body. This is very problematic and could limit the use of the devices in surgery. It is the goal of this research to develop a gripper that uses theGracias Laboratory's existing joints in conjunction with mechanical components to decrease the closing time. The purpose of including the mechanical components is to induce a state of instability at which time a small perturbation would cause the joint to close fully.The main concept of the research was to use the lateral buckling of a triangular gripper geometry and use a toggle mechanism to decrease the closure time of the device. This would create a snap-action device mimicking the quick closure of a Venus flytrap. All developed geometries were tested using finite element analysis to determine ifloading conditions produced the desired buckled shape. This research examines lateral buckling on the micro-scale and the possibility ofusing this phenomenon in a micro-gripper. Although a final geometry with the required deformed shaped was not found, this document contains suggestions for future geometries that may produce the correct deformed shape. It was determined through this work that in order to obtain the desired deformed shape, polymeric sections need to be added to the geometry. This simplifies the analysis and allows the triangular structure to buckle in the appropriate way due to the added joints. Future work for this project will be completed by undergraduate students at Bucknell University. Fabrication and testing of devices will be done at Johns Hopkins University in the Gracias Laboratory.
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Although the protozoan parasite, Trypanosoma brucei, can acquire lipids from its environment, recent reports have shown that it is also capable of de novo synthesis of all major phospholipids. Here we provide an overview of the biosynthetic pathways involved in phospholipid formation in T. brucei and highlight differences to corresponding pathways in other eukaryotes, with the aim of promoting trypanosomes as an attractive model organism to study lipid biosynthesis. We show that de novo synthesis of phosphatidylethanolamine involving CDP-activated intermediates is essential in T. brucei and that a reduction in its cellular content affects mitochondrial morphology and ultrastructure. In addition, we highlight that reduced levels of phosphatidylcholine inhibit nuclear division, suggesting a role for phosphatidylcholine formation in the control of cell division. Furthermore, we discuss possible routes leading to phosphatidylserine and cardiolipin formation in T. brucei and review the biosynthesis of phosphatidylinositol, which seems to take place in two separate compartments. Finally, we emphasize that T. brucei represents the only eukaryote so far that synthesizes all three sphingophospholipid classes, sphingomyelin, inositolphosphorylceramide and ethanolaminephosphorylceramide, and that their production is developmentally regulated.
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We describe how high-pressure freezing of infectious biological material can safely be accomplished with the help of membrane carriers. The method described is easy to perform; however, careful manipulations are required. Existing safety regulations must still be followed. However, the procedure reduces the risk of dissemination of infectious material.