1,722,704 research outputs found
Solids-liquid separation
No full textZhu, Jun. (1999). Solids-liquid separation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/148283
Tunable ZnO surface acoustic wave devices based on acoustoelectric interaction
No full textTunable surface acoustic wave (SAW) devices have been attracting considerable research efforts, as they are highly desired in advanced communication systems by offering versatile signal processing capability. Among various tuning mechanisms, the perturbation of the electrical boundary condition based on the acoustoelectric interaction in a semiconducting/piezoelectric multilayer structure is a promising approach to realize tunable SAW devices with low bias, large tunability, and small device dimension. To reduce the fabrication complexity and enhance the device reliability, the monolithic device structure is preferable.
This dissertation addresses the design and development of the tunable ZnO SAW devices based on the acoustoelectric interaction. Epitaxial ZnO and MgxZn1-xO multilayer structures grown by metal-organic chemical vapor deposition (MOCVD) on r-Al2O3 substrates are used as the basic structure, which offer advantages as high coupling coefficient and multimode SAW generation. The device related processing techniques, including wet chemical and dry etching of ZnO and MgxZn1-xO films, are investigated with respect to the etch rate, etch profile, surface morphology and process induced damage. The maximal 1:1 pattern edge slope has been achieved.
A prototype of ZnO UV SAW device has been demonstrated using semiconducting-piezoelectric ZnO multilayer structure, which enables the wireless output for sensor network. The interaction of the SAW with the UV induced carriers in the semiconducting ZnO layer results in a phase shift and an insertion loss change, as functions of the incident light wavelength and power. A phase shift of 107o is achieved at 365 nm for a light power of 2.32 mW/ cm2.
A prototype of ZnO based voltage controlled multi-mode tunable SAW device has been demonstrated through the integration of a depletion-type MIS structure (Al/SiO2/semiconducting ZnO) and a piezoelectric ZnO/r-Al2O3 system. The acoustic velocity tunability is achieved by changing the sheet conductivity of the semiconducting channel through the gate biasing. Due to the in-plane piezoelectric anisotropy of the ZnO/r-Al2O3 system, the device can be operated with both Sezawa and Love mode for gaseous and liquid sensing, respectively. Under -18 V bias, 420o and 277.3o phase shifts are achieved for Sezawa and Love mode operation, respectively.Ph.D.Includes bibliographical references (p. 142-149)
"Biohydrogen and Methane Production Through Fermentation of Liquid Swine Manure," 68th Minnesota Nutrition Conference and University of Minnesota Research Update Session: Modern Concepts in Livestock Production for 2007, Proceedings, September 18-19-2007, Minneapolis, Minnesota
No full textZhu, Jun; Wu, Xiao; Li, Yecong; Miller, Curtis. (2007). "Biohydrogen and Methane Production Through Fermentation of Liquid Swine Manure," 68th Minnesota Nutrition Conference and University of Minnesota Research Update Session: Modern Concepts in Livestock Production for 2007, Proceedings, September 18-19-2007, Minneapolis, Minnesota. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/202030
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Optimal physical pretreatment conditions for the release of organic matter from dairy manure determined by the orthogonal experiment design
No full textThe optimum physical conditions for releasing carbohydrate, protein and total phosphate were pH 2.0, reaction temperature 90oC, and particle size of <0.15mm, under which the carbohydrate and protein releasing rates could improve by 204.6 and 233.4%, and the total phosphorus concentration could increase from 0.21 mg/l to 6.5 mg/l.Sun, Jianping; Zhu, Jun; Li, Wenhong. (2011). Optimal physical pretreatment conditions for the release of organic matter from dairy manure determined by the orthogonal experiment design. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/119843
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
