Tweet I have seen many people asking for help in data mining forums and on other websites about how to choose a good thesis topic in data mining. Therefore, in this this post, I will address this question. Personally, I think that designing or improving data mining techniques is more challenging than using already existing techniques.
Release of nitrogen from granules of sulfur-coated urea Creator Jarrell, Wesley M. Urea granules are sprayed with molten sulfur, then holes in the sulfur coating are sealed with a layer of wax sealant. The sulfur coatings are mixtures of amorphous and crystalline allotropes of sulfur.
Coating thickness varies over the surface of each granule. The distribution of coating thickness among granules in a given lot of SCU depends on the conditions under which it is manufactured.
A model was constructed to predict the rate at which urea is released from SCU as a function of time. It was assumed that microorganisms break down coating materials until the urea is exposed to water. The urea dissolves and diffuses out of the granule into the soil.
Soil temperature, soil water content, and coating characteristics affect the rate of release. Diffusion of urea out of open SCU granules was examined theoretically and experimentally. Theoretical equations were developed which predict that diffusion of urea through small holes in the coating occurs in two stages.
The initial release rate was shown to be constant. After all the urea has dissolved, the rate of release decays exponentially.
To test the theory, granules of SCU were immersed in water and the rate of release of urea from these granules was measured for 70 days. It was found that the cumulative amount of urea released was an exponential function of time.
Urea was released 1. The large variability in hole sizes among open granules may account for the difference between predicted release rates and those measured experimentally. Granules of SCU which were alternately wetted and dried at 35 C released more urea than granules which were constantly immersed.
The breakdown of coatings may have been caused by removal of sealant from holes in the sulfur shell.
The objective of this thesis was to expand knowledge regarding biomechanical measurement of sculling force profiles and to understand how the PowerLine™ boat instrumentation system could be used effectively to measure and improve elite on-water sculling performance. manuscripta mathematica was founded in to provide a forum for the rapid communication of advances in mathematical research. Edited by an international board whose members represent a wide spectrum of research interests, manuscripta mathematica is now recognized as a leading source of information on the latest mathematical results. WAVES IN STEEP OPEN CHANNELS NEAR LAS VEGAS, NEVADA Submitted by y Water depth y b Base flow depth y b * Dimensionless base flow depth y n Normal flow depth this thesis will examine the method developed by Tsai and Yen to see if there are any areas of potential improvement. Ultimately, the.
Alternatively, a portion of the amorphous sulfur in the coating may have crystallized as the surface dried, causing cracks to open in the sulfur shell. Granules in water, the temperature of which was varied between 5 and 35 C each day, released urea at the same rate as samples maintained at constant temperature.
Equations were developed to predict the rate at which microbial populations increase and the rate at which each organism breaks down the coating materials. The rate of coating breakdown is the product of organism numbers and organism activity. To establish a relationship between the amount of coating removed and the fraction of granules which have been opened, granules were dipped in benzene for 1 to 10 minutes to remove portions of their coatings.
After dipping in benzene, the amount of coating removed was measured and the percentage of open granules was determined.
Based on the resulrs of this experiment, it was hypothesized that all SCU granules fall into one of three classes. The relationship between the amount of coating removed and the number of granules opened was linear for both Class 2 and Class 3 granules.
Release from SCU-4 was also measured at 5 and 15 C and in soil at bars soil water potential. The agreement between predicted and measured release indicated that for the temperature and soil water conditions studied, the rate of release was accurately predicted using the computer program.Scholar Commons > College of Engineering > Civil and Environmental Engineering > Theses and Dissertations.
Civil and Environmental Engineering Theses and Dissertations. Follow. Jump to: Theses/Dissertations from PDF. The Sustainability of Ion Exchange Water Treatment Technology, Adib Amini. PDF.
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ProQuest Dissertations and Theses Global (PQDT Global) is the world's most comprehensive collection of full-text dissertations and theses and is the official digital dissertations archive for the Library of . One of my PhD students lamented this week with me that she had a lot to juggle (taking children to and from schools and to and from activities, etc.) and that she needed a .
The DART-Europe E-theses Portal provides researchers with a single European Portal for the discovery of Electronic Theses and Dissertations, with access (at the time of this writing) to , open access research theses from Universities in . Open access (OA) refers to research outputs which are distributed online and free of cost or other barriers, and possibly with the addition of a Creative Commons license to promote reuse.
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