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Full-Text Articles in Mechanical Engineering
Nanoscale Solutions To Tailor Fiber Architectures For Realizing Composites With Triumvirate Properties, Vishnu Priya Ramineni
Nanoscale Solutions To Tailor Fiber Architectures For Realizing Composites With Triumvirate Properties, Vishnu Priya Ramineni
All Theses
The paramount need for the development of multifunctional, smart and adaptive material systems for application in industries like automobile, aeronautical and aerospace is undeniable. Polymer composites are fast becoming the primary material options to this demand in light of their superior mechanical properties, low density, high corrosion resistance and easy manufacturability. The design flexibility offered in terms of achieving higher specific properties and light weighting is the key reason behind their success. Among all the properties that composites possess, it is the stiffness, strength and toughness that most applications mandate. These properties however, provide complimentary and contrasting characteristics for composites …
Cost Estimation Model For Pan Based Carbon Fiber Manufacturing Process, Amaninder Singh Gill, Darian Visotsky, Laine Mears, Joshua D. Summers
Cost Estimation Model For Pan Based Carbon Fiber Manufacturing Process, Amaninder Singh Gill, Darian Visotsky, Laine Mears, Joshua D. Summers
Publications
A polyacrilonitrile (PAN) based carbon fiber manufacturing cost estimation model driven by weight is presented in this study. One of the biggest limiting factors in the large scale use of carbon fiber (CF) in manufacturing is its high cost. The costs involved in manufacturing the carbon fiber have been formalized into a cost model in order to facilitate the understanding of these factors. This can play a key role in manufacturing CF in a cost effective method. This cost model accounts for the fixed and variable costs involved in all stages of manufacturing, in addition to accounting for price elasticity.
Enrichment Of Diluted Cell Populations From Large Sample Volumes Using 3d Carbon-Electrode Dielectrophoresis, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Rodrigo Martinez-Duarte
Enrichment Of Diluted Cell Populations From Large Sample Volumes Using 3d Carbon-Electrode Dielectrophoresis, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Rodrigo Martinez-Duarte
Publications
Here, we report on an enrichment protocol using carbon electrodedielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 106–102 cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL …
Towards Additive Manufacturing Of Tungsten Carbide Using Renewable Resources, Monsur Islam, Rodrigo Martinez-Duarte
Towards Additive Manufacturing Of Tungsten Carbide Using Renewable Resources, Monsur Islam, Rodrigo Martinez-Duarte
Publications
Here we present preliminary results towards additive manufacturing of carbides. A biopolymer-metal oxide gel composite composed of iota-carrageenan, chitin and tungsten trioxide (WO3) was shaped and heat treated in order to obtain carbide structures. Upon heat treatment of this composite above 900 °C, a porous structure of tungsten carbide (WC) was obtained. The synthesis mechanism of WC was estimated using the result from XRD characterization. The synthesized WC was characterized with SEM, TEM and nitrogen absorption-desorption to investigate the morphology, particle size and pore size distribution. The carbonaceous materials retained the original shape. The ongoing work is on …
Shrinkage Analysis Of Carbon Micro Structures Derived From Su-8 Photoresist, Rucha Natu, Monsur Islam, Rodrigo Martinez-Duarte
Shrinkage Analysis Of Carbon Micro Structures Derived From Su-8 Photoresist, Rucha Natu, Monsur Islam, Rodrigo Martinez-Duarte
Publications
We present preliminary results for the analysis of shrinkage of 3D carbon posts obtained by the pyrolysis of SU-8 precursor structures, in a technique known as Carbon MEMS. Though the shrinkage in the carbon structures is highly reproducible, there is a strong dependence of this shrinkage on the initial dimensions of the SU-8 pillars. Our hypothesis is that the shrinkage depends upon the area available for degassing during carbonization. In this work, this idea is used to analyze shrinkage in cylindrical pillars. The results obtained are studied based on the ratio of lateral and top surface area available for degassing …
Synthesis Of Titanium Oxycarbide Through Carbothermal Reduction Of Titanium Dioxide Nanoparticles And Renewable Biopolymers, Joshua Paul Flach, Paulo Henrique Figuereido De Lima, Joshua Craig Sparks, Monsur Islam, Rodrigo Martinez-Duarte
Synthesis Of Titanium Oxycarbide Through Carbothermal Reduction Of Titanium Dioxide Nanoparticles And Renewable Biopolymers, Joshua Paul Flach, Paulo Henrique Figuereido De Lima, Joshua Craig Sparks, Monsur Islam, Rodrigo Martinez-Duarte
Publications
The goal of this is study is to explore the feasibility of a sustainable method of titanium oxycarbide synthesis through carbothermal reduction of a biopolymer composite. The reaction was studied at different temperatures in vacuum environments and at multiple TiO2:C ratios in order to determine how these parameters affect the formation of titanium oxycarbide. The results indicate that both the heat treatment and the carbon ratios have a significant impact on the O/C ratio, and therefore, molecular composition and crystal structure of the titanium oxycarbide. The use of renewable biopolymers as a carbon source in the synthesis of …
3d Carbon-Electrode Dielectrophoresis For Enrichment Of A Small Cell Population From A Large Sample Volume, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Guillermo Contreras-Dávila, Rodrigo Martinez-Duarte
3d Carbon-Electrode Dielectrophoresis For Enrichment Of A Small Cell Population From A Large Sample Volume, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Guillermo Contreras-Dávila, Rodrigo Martinez-Duarte
Publications
Isolation and enrichment of cells from a diluted sample is necessary for different clinical applications. Here we have demonstrated the use of 3D carbon electrode dielectrophoresis (DEP) to process a diluted yeast sample featuring concentration as low as 102 cells/ml. The yeast cells in the sample were first trapped on carbon electrodes by implementing positive DEP force and then released and concentrated in a small volume of clean buffer. The maximum limit of the cell trapping for our device was found to be around 4000 cells. Using 10 µl/min, an enrichment of 154.2 ± 23.7 folds was achieved, where sample …
Assessing The Advantages Of Using Square Wave Signals For Particle Trapping In Carbon-Electrode Dielectrophoresis, Guillermo Contreras-Dávila, Jose I. Gomez-Quiñones, Victor H. Pérez-González, Rodrigo Martinez-Duarte
Assessing The Advantages Of Using Square Wave Signals For Particle Trapping In Carbon-Electrode Dielectrophoresis, Guillermo Contreras-Dávila, Jose I. Gomez-Quiñones, Victor H. Pérez-González, Rodrigo Martinez-Duarte
Publications
Here we present an improvement on the trapping efficiency of 3D carbon electrode Dielectrophoresis (carbonDEP) by using alternative signal geometries to the more traditional sine used to stimulate the electrodes. In particular, a square waveform is used. Theoretical analysis was based on the Root Mean Square (RMS) values and the Fourier Series Expansion of these signals. Computational modeling was performed to calculate the DEP force generated by the two signal waveforms and allowed for direct comparison. The trapping efficiency between square and sine signals was then determined experimentally. Given the same experiment characteristics, the use of square signals allows for …
Synthesis Of Tungsten Carbide From Bacterial Cellulose, Monsur Islam, Rodrigo Martinez-Duarte
Synthesis Of Tungsten Carbide From Bacterial Cellulose, Monsur Islam, Rodrigo Martinez-Duarte
Publications
Here we present preliminary experiments for the synthesis of carbide material using bacterial cellulose as carbon source. We used bacteria cellulose available as Nata de Coco and infiltrated it with tungsten trioxide (WO3) nanoparticles. This composite was heat treated at 1300 °C in nitrogen atmosphere. The XRD pattern confirms the synthesis of tungsten carbide (WC) in the carbonaceous material, though a significant amount of metallic tungsten remained unreacted. SEM images shows that WC particles are present only at the surface of the carbon, which may be a consequence of improper infiltration or collapse of carbon matrix during heat …