Richard Lab:Gas Flux: Difference between revisions

Latest revision as of 16:08, 9 February 2010

gaseous emission data is collected using a static flux chamber and a photoacoustic sensor.
an Excel program is then used to extract relevant data (from the continuous data collected by the photoacoustic sensor every minute). The same program also calculates the flux of selected gases from the tested surface, using Pedersen's equation (2001).
selected data are copied and pasted as values into a compiled data set
a regression analysis is performed to evaluate the effect of time, biofilter treatment, and other input variables on the flux level of each analyzed gas: ammonia, methane, carbon dioxide, nitrous oxide and water vapor. The Sagata Regression Pro software (ltd) is used: go to regression > pick inputs > pick outputs > chose data types (categorical or continuous) > chose regression model (to evaluate interactions create input variables made of factors evaluate for interaction amongst them, multiplied by each other) > go to output, get response vs. factors for preliminary graphs > choose indicative title for the output sheet > click ok.
the statistical analysis output is interpreted: the first Anova table shows possible treatment effect. The "term significance" table shows effect of individual factors (or interactions).

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 ==Overview==
+*gaseous emission data is collected using a [http://www.abe.psu.edu/bioconversion/gas_sampling.ppt static flux chamber and a photoacoustic sensor].
+*an [http://www.abe.psu.edu/bioconversion/programPAS.xls Excel program] is then used to extract relevant data (from the continuous data collected by the photoacoustic sensor every minute). The same program also calculates the flux of selected gases from the tested surface, using Pedersen's equation (2001).
+*selected data are copied and pasted as values into a compiled data set
+*a regression analysis is performed to evaluate the effect of time, biofilter treatment, and other input variables on the flux level of each analyzed gas: ammonia, methane, carbon dioxide, nitrous oxide and water vapor. The Sagata Regression Pro software (ltd) is used: go to regression > pick inputs > pick outputs > chose data types (categorical or continuous) > chose regression model (to evaluate interactions create input variables made of factors evaluate for interaction amongst them, multiplied by each other) > go to output, get response vs. factors for preliminary graphs > choose indicative title for the output sheet > click ok.
+*the statistical analysis output is interpreted: the first Anova table shows possible treatment effect. The "term significance" table shows effect of individual factors (or interactions).
 ==Materials==