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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Membrane-based protein preconcentration microfluidic devices /

Li, Yi, January 2006 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2006. / Includes bibliographical references
12

Synthesis of nano-sized silicon nitride powder in microchannel reactors /

Hirayama, Michiru. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 59-61). Also available on the World Wide Web.
13

Cellulose/polysulfone nanocomposites /

Noorani, Sweda. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 72-74). Also available on the World Wide Web.
14

Zeolite membrane microreactor for fine chemical production /

Lau, Wai Ngar. January 2006 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 148-167). Also available in electronic version.
15

Design, fabrication and testing of a high temperature ceramic microreactor for synthesizing silicon nitride nanoparticles /

Jain, Kartavya. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 139-146). Also available on the World Wide Web.
16

Development of microreactor systems for electrocatalytic studies of methanol oxidation at elevated temperatures /

Arvindan, Nallakkan Subbiah. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 183-191).
17

Continuous and rapid synthesis of nanoclusters and nanocrystals using scalable microstructured reactors /

Jin, Hyung Dae. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2011. / Printout. Includes bibliographical references (leaves 137-146). Also available on the World Wide Web.
18

Studying chemical oscillators in a continuous flow microreactor by laser scanning confocal microscopy.

January 2012 (has links)
本论文介绍了一种基于扫描共聚焦显微镜和微流反应器用于研究化学振动子同步的系统。这个系统利用300微米的PNIPAm胶体颗粒作为振动子,Ru(vmbpy)(bpy)₂(PF₆)₂ 被参杂到振动子里充当BelousovZhabotinsky(BZ)振荡反应的催化剂。扫描共聚焦显微镜具有很高的灵敏度,可以给出高质量的图片以供研究分析。通过实验证明低于56W/cm²强度的扫描激光对BZ反应没有影响。这里所运用的微流反应器包括两个部分,PMMA材质的微池和PDMS材质的流道。此反应器可通过流道不停地补充BZ反应的反应物从而保证振荡的一致性。 / 通通过此系统,我们可以研究不同的两个振动子的同步问题。在实验中,振动子间的同步是由两者间的距离决定的。振动子在靠近时同步在分开至临界距离以外处不同步。另外,我利用COMSOL来模拟实验中的现象,发现模拟的结果和实验中的现象十分吻合。 / In this thesis, I present an experimental platform based on laser scanning confocal microscopy (LSCM) and continuous flow microreactor (CFMR) to study coupled chemical oscillators. PNIPAm gel particles around 300 micron were synthesized in the microfluidic device as the oscillators. Ru(vmbpy)(bpy)₂(PF₆)₂ was used as the catalyst of the BelousovZhabotinsky (BZ) reaction. The LSCM offers a good signal-to-noise ratio and better imaging quality. We demonstrated that the scanning laser with the power below 56W/cm² had no influence to BZ reaction. The CFMR, consisting of the PMMA microwell and the PDMS microchannel, can maintain the oscillation of the oscillators with a continuous supply of the BZ mixture. / The synchronization of the double heterogeneous oscillators was studied by the platform. The coupling intensity was controlled by changing the distance between the two oscillators. Results showed that the synchronization occurred as the oscillators were close and was lost as the oscillators were separated beyond a critical distance. The results of the numerical simulation by COMSOL agreed well with the experimental observation. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Guo, Dameng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 40-41). / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgement --- p.iii / Table of contents --- p.iv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Synchronization of chemical oscillating systems --- p.1 / Chapter 1.2 --- The Belousov-Zhabotinsky reaction --- p.4 / Chapter 1.2.1 --- FKN model --- p.5 / Chapter 1.2.2 --- Effect of light illumination on ruthenium catalyzed BZ reaction --- p.7 / Chapter 1.2.3 --- Luminescence of ruthenium catalyzed in the BZ reaction --- p.8 / Chapter 1.3 --- Oscillators based on the BZ reaction --- p.9 / Chapter 1.4 --- Detection methods for the BZ oscillating systems --- p.10 / Chapter 1.4.1 --- Ion selective electrode and optical microscopy --- p.10 / Chapter 1.4.2 --- Objective of the research --- p.10 / Chapter Chapter 2 --- LSCM and continuous flow microreactor based platform --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Experimental --- p.13 / Chapter 2.2.1 --- The fabrication of the oscillators --- p.13 / Chapter 2.2.2 --- The fabrication of the CFMR --- p.14 / Chapter 2.2.3 --- The detection method --- p.16 / Chapter 2.3 --- Results and discussions --- p.16 / Chapter 2.3.1 --- The comparison of PMMA and PDMS microreactors --- p.16 / Chapter 2.3.2 --- The flow rate of the BZ mixture to maintain the oscillation --- p.18 / Chapter 2.3.3 --- The size of the microreactor --- p.19 / Chapter 2.3.4 --- The factors to reduce the influence of the laser on the oscillators --- p.21 / Chapter 2.4 --- Conclusions --- p.23 / Chapter Chapter 3 --- The studying of the synchronization of the double oscillators --- p.24 / Chapter 3.1 --- Introduction --- p.24 / Chapter 3.1.1 --- Kuramoto model for illustrating the synchronization of double oscillators --- p.24 / Chapter 3.1.2 --- Transition from disorder to synchronization --- p.25 / Chapter 3.2 --- Experimental and simulation --- p.26 / Chapter 3.2.1 --- The dispensing and detection of the oscillators in the microreactor --- p.26 / Chapter 3.2.2 --- The simulation model --- p.27 / Chapter 3.3 --- Results and discussion --- p.28 / Chapter 3.3.1 --- The controlling of the coupling intensity --- p.28 / Chapter 3.3.2 --- The results of the synchronization --- p.30 / Chapter 3.3.2.1 --- Synchronization --- p.30 / Chapter 3.2.2.2 --- The critical distance for the synchronization and the transition --- p.31 / Chapter 3.3.3 --- The results of the simulation --- p.34 / Chapter 3.4 --- Conclusion --- p.35 / Chapter Chapter 4 --- Conclusion --- p.37 / Chapter 4.1 --- Summary --- p.37 / Chapter 4.2 --- Discussions and future perspectives --- p.38 / Reference --- p.40 / Appendix --- p.42 / Chapter 1. --- Code in Matlab for calculating the RGB value of ROI in the images from the LSCM --- p.42 / Chapter 2. --- The power of the laser --- p.43 / Chapter 2.1 --- The power of the laser in the LSCM --- p.43 / Chapter 2.2 --- The irradiation power on the oscillators --- p.44 / Chapter 3. --- The energy transferred to the oscillator --- p.44 / Chapter 4. --- The model in COMSOL --- p.45
19

A microfluidic platform for producing nanoliter-scale double emulsion and its application in protein crystallization / CUHK electronic theses & dissertations collection

January 2015 (has links)
This thesis describes the design and construction of a microfluidic platform for producing stable double emulsions and its application in protein crystallization. Emulsion-based systems has been widely utilized to encapsulate various substances in both industrial applications and fundamental researches. Microfluidics is a promising technique to handle small volumes of liquid and produce such kind of emulsion-based microreactors. / Two different types of microfluidic devices were constructed to generate double emulsions: one was the planar PDMS-based device, and the other was the 3D Glass-Teflon hybrid device. Both devices were demonstrated with the ability to produce a high level of monodispersity in the size distribution of double emulsions with volumes ranging from dozens to hundreds of nanoliter. Compared to the PDMS-based microfluidic devices which are commonly used in the microfluidic field but require sophisticated soft-lithography procedures and selective surface modifications, the Glass-Teflon hybrid microfluidic devices are more competitive in the aspects of low cost, ease of fabrication, reliable performance, and reusability. Double emulsions stored in confined environments were proved to be more stable than that in open environments. With the prolonged lifespan of double emulsions, long-term reactions could be conducted inside the microreactors. In addition, the permeability of the oil shell in double emulsions provided means to precisely control the bio/chemical environments of the core droplets by adjusting the composition of the oil phase or the osmotic pressure differences between the inner and outer phases. The microfluidic platform was established to be a simple and reliable tool for producing stable double emulsion-based microreactors. / We employed the microfluidic platform to perform protein crystallization in the inner aqueous phase of double emulsions.Double emulsions can provide ideal conditions to explore protein crystallization for the advantages of convection-free environment and homogeneous interface. Both vapor diffusion method and microbatch method were implemented in the double emulsion-based approaches using four model proteins to grow crystals successfully. The property of water-oil interface was demonstrated to be a critical factor for nucleation and appropriate surfactants should be chosen to prevent protein adsorption at interface. The results from the volume effect study showed a trend of fewer crystals formed and longer incubation time needed with a reduction in the protein solution volume, suggesting that the nucleation in protein crystallization process can be controlled by changing the volume of protein solutions.Finally, sparse matrix screening was achieved using the double emulsion-based microbatch method. The double emulsion-based approaches for protein crystallization were established to be a promising tool for reducing heterogeneous nucleation and gaining the chance to obtain one crystal in one reactor. / 本論文發展了一種用於產生和存儲穩定雙乳液(double emulsion)的微流控實驗平台,對其製備方法以及把雙乳液用作微型反應容器并在其內核進行蛋白質結晶做了系列的研究和探討。 / 首先,我們製作了兩種製備雙乳液的微流控裝置:第一種是基於聚二甲基硅氧烷(PDMS)的平面型微流控芯片;另一種是由Teflon管、硅膠管和玻璃毛細管組裝而成的三維結構微流控裝置。兩套裝置均可以產生不同納升體積的、具有高單一分散性的雙乳液。製作第一種微流控芯片需要軟光刻及選擇性表面修飾等相關的儀器和步驟;相比之下,第二種微流控裝置在製作消耗的時間和材料,製作簡易性、性能可靠性和可重複使用等方面證明有明顯優勢。通過把雙乳液以低密度存儲在受限容器中,雙乳液的壽命被顯著延長,為將其作為微型反應器提供了可能。此外,雙乳液的中間油層可以起到半透膜功能,可以用調節油相組成及內外水相滲透壓的方式精確控制雙乳液內核溶液的濃度環境。 / 雙乳液的內核是一個沒有對流影響的環境及具有高度均一的界面,可以為蛋白質結晶提供理想空間。我們以製備的雙乳液為微型反應容器,在其內核進行了一系列蛋白質結晶實驗。四種蛋白質分別以類氣相擴散方法(vapor diffusion method)和類微液滴方法(microbatch method)在納升量級進行了結晶實驗,并得到了良好的蛋白質晶體。雙乳液界面會對結晶過程產生明顯影響,在實驗中我們選用了適當的表面活性劑來阻止蛋白質分子的界面吸附。在研究體積效應對蛋白質結晶的影響中,我們發現隨著體積減小,在單一容器內會得到更少數目的晶體,但結晶時間會增加。這為通過控制蛋白質溶液體積來研究成核過程提供可能的途徑。最後,我們把這種基於雙乳液的微型反應容器應用到大數量的結晶條件篩選,通過偏光顯微鏡觀察對比,得到了與普通微液滴方法一致的結晶條件。這種基於雙乳液的微型反應容器為研究蛋白質結晶提供了一種可有效阻止異相成核的新方法。 / Zhu, Deyong. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 80-90). / Abstracts also in Chinese. / Title from PDF title page (viewed on 05, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
20

Continuous flow microreactor for chemical bath deposition : a novel approach to the deposition of polycrystalline semiconductor thin films

Mugdur, Prakash 11 March 2005 (has links)
Over the years, chemical bath deposition (CBD) is being widely used in the fabrication of Cu (In, Ga) Se��� and CdTe based solar cells and photovoltaics. Many chalcogenides have been successfully deposited by this technique and it has received a great deal of attention owing to its low temperature and low-cost nature. CdS, an important layer in heterojunction solar cells and other optoelectronic devices, has been successfully deposited by this technique, which is normally carried out as a batch process. But a major disadvantage of batch CBD is the formation of particles and also unwanted deposition generating a lot of waste and thus resulting in defective devices. In this study, we have developed a continuous flow microreactor for CBD to overcome the drawbacks of batch process. This novel microreactor setup makes use of a micromixer for efficient mixing of the reactant streams and helps in controlling the particle size and distribution before the solution impinges on the hot substrate. CdS semiconductor thin films were successfully deposited on oxidized silicon substrates using the microreactor setup and a batch reactor as well. Comparisons of nanostructured thin films were performed by various characterization techniques. The surface morphology of the deposited films, carried out by AFM, SEM and Dektak surface profiler, clearly indicated an improved film quality in case of microreactor. This setup can also be used to deposit various other compound semiconductor thin films with improved film quality and minimum waste production. / Graduation date: 2005

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