Engineering Commons^™

Applied Fourier Transform Near-Infrared Techniques For Biomass Compositional Analysis, Lu Liu

Masters Theses

A new method for rapid chemical analysis of lignocellulosic biomass was developed using Fourier transform near-infrared (FT-NIR) spectroscopic techniques. The new method is less time-consuming and expensive than traditional wet chemistry. A mathematical model correlated FT-NIR spectra with concentrations determined by wet chemistry. Chemical compositions of corn stover and switchgrass were evaluated in terms of glucose, xylose, galactose, arabinose, mannose, lignin, and ash. Model development evaluated multivariate regressions, spectral transform algorithms, and spectral pretreatments and selected partial least squares regression, log(1/R), and extended multiplicative signal correction, respectively. Chemical composition results indicated greater variability in corn stover than switchgrass, especially among …

Design And Evaluation Of A Non-Intrusive Corn Population Sensor, Haizhou Li

Doctoral Dissertations

Specific objectives of this study were to develop, prototype, and test a corn population sensor. Both intrusive mechanical and non-intrusive capacitive techniques have been used to develop the stalk population sensors in previous research. However, neither could generate consistent performance. The mechanical method required high maintenance and resulted in significant underestimations of stalk counts. The performance of capacitive systems was limited by inadequate sensing distance, especially at low stalk moisture levels.

In this research, the sensitivity of the capacitive sensor was optimized for corn stalks. This system utilized a single-sided capacitive sensor, Wien bridge oscillator, phase-locked loop, and an operational …

Risk Analysis Of Decentralized Wastewater Design Flows, Patrick Andrew Dobbs

Masters Theses

Decentralized wastewater treatment systems are often designed at flows of either 284 L/person/d (75 gal/person/d) or 568 L/bedroom/d (150 gal/bedroom/d). Water use data suggest that designing systems at these flow rates can lead to overly conservative designs. A study quantifying the risk of failure (exceeding a system design flow) was needed to create a design basis for future systems. The objectives of the study were to quantify the risk of failure of decentralized system design flows depending on the number of residences served by a system and to develop new guidelines for design flows of cluster systems based on quantifiable …