International journal of micro-nano scale transport最新文献

{"title":"Enhanced Boiling of a Dielectric Liquid on Copper Nanowire Surfaces","authors":"Y. Im, Y. Joshi, C. Dietz, Seung S. Lee","doi":"10.1260/1759-3093.1.1.79","DOIUrl":"https://doi.org/10.1260/1759-3093.1.1.79","url":null,"abstract":"Copper nanowire arrays on a silicon (Si) substrate were fabricated by electro-chemical deposition through an anodic aluminum oxide (AAO) template to generate a high performance boiling surface. In this study, the pitch (~300 nm) and diameter (~200 nm) of the nanowires were fixed, and the height was varied between 1 and 8 μm. It is observed that copper nanowire surfaces increase the critical heat flux and reduce the incipience superheat compared to the baseline experiments, which were performed using a plain surface without nanowires. The work reported here is a major enhancement over previous studies on structured surfaces, which mainly considered structures which were on the order of 100 μm.","PeriodicalId":89942,"journal":{"name":"International journal of micro-nano scale transport","volume":"1 1","pages":"79-96"},"PeriodicalIF":0.0,"publicationDate":"2010-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1260/1759-3093.1.1.79","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66151163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Multi-scale Models for Transport Processes Involving Catalytic Reactions in SOFCs","authors":"B. Sundén, Jinliang Yuan","doi":"10.1260/1759-3093.1.1.37","DOIUrl":"https://doi.org/10.1260/1759-3093.1.1.37","url":null,"abstract":"Several physical phenomena appear in anode-supported solid oxide fuel cells (SOFCs), such as multi-component gas species/charge flow, thermal energy and mass transfer. Meanwhile, generation and consumption of gas- and surface-phase species together with electric current production are involved at the active sites in different length scales. Therefore, various reactions in SOFCs are strongly coupled with the transport processes making the physical phenomena more complicated. An effective anode is the one that correctly balances each of the transport processes and the reactions. To deeply understand the chemical-reacting transport processes in the porous anode, a fully three-dimensional numerical calculation method (CFD approach) is further developed. The considered domain includes the porous anode, fuel gas flow channel and the solid interconnects. By calculating surface-phase species, the gas-phase species/heat generation and consumption related to the internal reforming reactions and the electrochemical reactions have been employed. The variable thermal-physical properties and transport parameters of the fuel gas mixture have also been taken into account. Furthermore, the heat transfer due to the fuel gas diffusion is implemented into the energy balance based on multicomponent diffusion models. A multi-step heterogeneous steam reaction scheme based on the micro and detailed reaction mechanisms of Ni catalyst is employed in this study. The surface reactions include 42 irreversible elementary ones, and they account for the steam reforming, the water-gas shift reforming and Boudouard reactions. This microscopic reaction model describes the adsorption and desorption reactions of 6 gasphase species (H 2 , CO, CH 4 , CO 2 , H 2 O and O 2 ) and surface reactions of 12 surfaceadsorbed species (Ni s , H s , O s , OH s , HCO s , CH s , CH 2s , CH 3s , CH 4s , CO s , CO 2s , H 2 O s ). Simulation results are presented and discussed in terms of the gas-phase species and temperature distributions, the chemical reaction rates of the gas- and surface chemical species, the catalyst surface coverage and the effects on the transport processes.","PeriodicalId":89942,"journal":{"name":"International journal of micro-nano scale transport","volume":"1 1","pages":"37-56"},"PeriodicalIF":0.0,"publicationDate":"2010-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66151121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Analysis and Optimization of Wire - Sandwiched Micro Heat Pipes","authors":"R. Rag, C. Sobhan","doi":"10.1260/1759-3093.1.1.57","DOIUrl":"https://doi.org/10.1260/1759-3093.1.1.57","url":null,"abstract":"Micro heat pipes are a promising option for the thermal management of microelectronic systems with high heat flux dissipation rates. A computational analysis is performed on wire-sandwiched micro heat pipes, a relatively new design of micro heat pipes, which utilizes an array of wires sandwiched between metallic plates to produce the flow channels. A transient one-dimensional model incorporating the longitudinal variations in the flow cross sections of the liquid and vapor media has been utilized, while developing the governing equations for the analysis. A fully implicit finite difference scheme is utilized to obtain solutions for the velocity, pressure and temperature distributions in the vapor and the liquid phases. The performance of the heat pipe has been obtained, with the effective thermal conductivity as the indicator, and extensive optimization studies have been performed with respect to the geometric parameters namely the length of the heat pipe sections, the diameter and pitch of the wires in t...","PeriodicalId":89942,"journal":{"name":"International journal of micro-nano scale transport","volume":"1 1","pages":"57-78"},"PeriodicalIF":0.0,"publicationDate":"2010-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66151155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concentration gradients in microfluidic 3D matrix cell culture systems","authors":"I. Zervantonakis, Seok Chung, R. Sudo, Meng Zhang, J. Charest, R. Kamm","doi":"10.1260/1759-3093.1.1.27","DOIUrl":"https://doi.org/10.1260/1759-3093.1.1.27","url":null,"abstract":"Microfluidic technology enables the creation of well-defined cell culture environments, which integrate the control of multiple biophysical and biochemical cues for designing novel in vitro assays. Growth-factor concentration gradients play a critical role in a wide range of biological processes ranging from development to cancer, guiding cell migration and influencing cell signaling. We present a microfluidic device capable of generating stable concentration gradients in a 3D matrix, while allowing for direct imaging of cellular behavior. The design consists of polydimethylsiloxane microchannels interconnected through 3D matrices. Optical access of the 3D matrix permits direct observation of invasive properties of cells seeded inside the channels or embedded in the matrix. An important characteristic of the microfluidic platform is the capability to generate reproducible, stable and quantifiable concentration gradients that are essential for systematic studies of soluble factor signaling in chemotaxis as...","PeriodicalId":89942,"journal":{"name":"International journal of micro-nano scale transport","volume":"1 1","pages":"27-36"},"PeriodicalIF":0.0,"publicationDate":"2010-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1260/1759-3093.1.1.27","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66151112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}