Methods of Determination for Effective Diffusion Coefficient During Convective Drying of Clay Products
© 2012 Vasic et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Methods of Determination for Effective Diffusion Coefficient During Convective Drying of Clay Products
CONVECTIVE DRYING OF POULTRY MANURE BY DIFFERENT AIR SPEEDS
The high content of water in poultry manure creates problems for its collection, transport and storage in the large scale farms with laying hen breeding. Other problems with high moisture of manure are in the case of application of manure in the crop production or in the processing for another purpose of the use. The aim of this paper is to inform about the experimental and theoretical investigations of moisture content reduction from poultry manure by drying. Based on the experimental data we found the theoretical drying coefficient, useful for description and modelling of the drying process, calculated the theoretical results of moisture removal and compared with the experimental results obtained from the measurement. Using the experimental data with different convective air speed in the laboratory conditions there was calculated the drying coefficient depending on the drying time and air speed at constant temperature. The influence of the air speed was recognised as an important parameter, which can serve especially in the design and construction of the new equipment with the belts for housing of poultry or improvement of the use of the drying tunnel or in similar applications.
Development of new analytical methods for the determination of caffeine content in aqueous solution of green coffee beans
BackgroundThis study was conducted to develop fast and cost effective methods for the determination of caffeine in green coffee beans. In the present work direct determination of caffeine in aqueous solution of green coffee bean was performed using FT-IR-ATR and fluorescence spectrophotometry. Caffeine was also directly determined in dimethylformamide solution using NIR spectroscopy with univariate calibration technique.ResultsThe percentage of caffeine for the same sample of green coffee beans was determined using the three newly developed methods. The caffeine content of the green coffee beans was found to be 1.52 ± 0.09 (% w/w) using FT-IR-ATR, 1.50 ± 0.14 (% w/w) using NIR and 1.50 ± 0.05 (% w/w) using fluorescence spectroscopy. The means of the three methods were compared by applying one way analysis of variance and at p = 0.05 significance level the means were not significantly different. The percentage of caffeine in the same sample of green coffee bean was also determined by using the literature reported UV/Vis spectrophotometric method for comparison and found to be 1.40 ± 0.02 (% w/w).ConclusionNew simple, rapid and inexpensive methods were developed for direct determination of caffeine content in aqueous solution of green coffee beans using FT-IR-ATR and fluorescence spectrophotometries. NIR spectrophotometry can also be used as alternative choice of caffeine determination using reduced amount of organic solvent (dimethylformamide) and univariate calibration technique. These analytical methods may therefore, be recommended for the rapid, simple, safe and cost effective determination of caffeine in green coffee beans.