The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Reiner Brunsch - One of the best experts on this subject based on the ideXlab platform.
-
Developing the 85Kr tracer gas technique for air exchange rate measurements in naturally ventilated animal buildings
Biosystems Engineering, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Experiments were performed to study air exchange rates (AER) occurring in naturally ventilated dairy buildings during summer seasons 2006 to 2010. A tracer gas technique (TG) for AER measurements was developed. The AERs were determined by decay of radioactive tracer Krypton-85, and CO 2 -balance used as the reference method (RM). During each experiment, continuous measurements of gaseous concentrations (NH 3 , CO 2 , CH 4 and N 2 O) inside and outside the building and 85 Kr tracer gas experiments were performed. The combined factors investigated were release over feeding table (a 1 ) or over the manure alley (a 2 ), average α-values (b 1 ) or the sum of impulses (b 2 ), selected Radiation counts (c 1 ) or all Radiation counts (c 2 ). The results were compared using Pearson correlation analysis, developing a linear regression model, and testing the differences between the factor combinations and the RM using an ANOVA model. There were differences between impulses (Pr > |t| = 0.0013), where the sum of impulses showed better results than the average α-values. Although there was no difference (Pr > |t| = 0.344) between the readings of the Radiation counts, it was considered that by using all the readings of the Radiation Counters it was more representative and easier to calculate the AER. The best factor combinations, having the highest coefficient of determination values R 2 , and the most reliable parameter estimates, were: a 1 b 2 c 2 ( R 2 = 0.94; 1.63 ± 0.14); and a 1 b 1 c 1 ( R 2 = 0.97; 2.03 ± 0.11). The gaseous emissions, subject to the RM, were 3.9, 19, 1656, and 0.96 g h −1 AU −1 (AU is animal unit of 500 kg) for NH 3 , CH 4 , CO 2 and N 2 O respectively.
-
Implementation of Radioactive 85Kr for Ventilation Rate Measurements in Dairy Barns
2011 Louisville Kentucky August 7 - August 10 2011, 2011Co-Authors: Mohamed Samer, Werner Berg, Christiane Löbsin, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, Olaf Tober, P. Sanftleben, Reiner BrunschAbstract:Quantifying gaseous emissions from naturally ventilated animal buildings is a particularly difficult task and associated with large uncertainties. One aspect is to measure the ventilation rate and then to quantify the gaseous emissions. Therefore, the ventilation rate was determined by two methods, simultaneously. Fifteen field experiments were carried out to study the ventilation rate in a naturally ventilated dairy barn located in Northern Germany during three consecutive winter seasons. The air exchange rates and then the ventilation rates were determined by the decay of the radioactive tracer Krypton-85, and the carbon dioxide (CO2) balance which is the reference method. Afterwards, the results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. During each field experiment, continuous measurements of gas concentrations (NH3, CO2, CH4, and N2O) inside and outside the building and 85Kr tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The tracer gas technique was further developed for better application through winter measurements. Where, eight combination factors were tested which are: 85Kr line release source vs. 85Kr point release source, average a-values vs. sum impulses, selected Radiation Counters vs. all Radiation Counters. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O respectively.
-
Winter Measurements of Air Exchange Rates Using Tracer Gas Technique and Quantification of Gaseous Emissions from a Naturally Ventilated Dairy Barn
Applied Engineering in Agriculture, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Measuring the ventilation rates and then quantifying the gaseous emissions from naturally ventilated barns is a particularly difficult task and associated with large uncertainties; where no accurate, reliable, and online method is available for ventilation rate measurements. Therefore, the objective of this study was to develop further the tracer gas technique (TG) for ventilation rate measurements through winter seasons. Fifteen field experiments were carried out to study the ventilation rates in a naturally ventilated dairy barn located in North Germany through three consecutive winter seasons. During each field experiment, continuous measurements of gaseous concentrations (NH3, CO2, CH4, and N2O) inside and outside the barn and tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The air exchange rates (AERs) and then the ventilation rates were estimated by the TG and the CO2-balance which was set as reference method, in this study, for the purpose of statistical analysis. Three factors with two levels each were tested and they are: 85Kr point release source versus 85Kr line release source, average a-values versus sum impulses, selected Radiation Counters versus all Radiation Counters; resulting in eight factor combinations. The results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O, respectively.
Mohamed Samer - One of the best experts on this subject based on the ideXlab platform.
-
Developing the 85Kr tracer gas technique for air exchange rate measurements in naturally ventilated animal buildings
Biosystems Engineering, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Experiments were performed to study air exchange rates (AER) occurring in naturally ventilated dairy buildings during summer seasons 2006 to 2010. A tracer gas technique (TG) for AER measurements was developed. The AERs were determined by decay of radioactive tracer Krypton-85, and CO 2 -balance used as the reference method (RM). During each experiment, continuous measurements of gaseous concentrations (NH 3 , CO 2 , CH 4 and N 2 O) inside and outside the building and 85 Kr tracer gas experiments were performed. The combined factors investigated were release over feeding table (a 1 ) or over the manure alley (a 2 ), average α-values (b 1 ) or the sum of impulses (b 2 ), selected Radiation counts (c 1 ) or all Radiation counts (c 2 ). The results were compared using Pearson correlation analysis, developing a linear regression model, and testing the differences between the factor combinations and the RM using an ANOVA model. There were differences between impulses (Pr > |t| = 0.0013), where the sum of impulses showed better results than the average α-values. Although there was no difference (Pr > |t| = 0.344) between the readings of the Radiation counts, it was considered that by using all the readings of the Radiation Counters it was more representative and easier to calculate the AER. The best factor combinations, having the highest coefficient of determination values R 2 , and the most reliable parameter estimates, were: a 1 b 2 c 2 ( R 2 = 0.94; 1.63 ± 0.14); and a 1 b 1 c 1 ( R 2 = 0.97; 2.03 ± 0.11). The gaseous emissions, subject to the RM, were 3.9, 19, 1656, and 0.96 g h −1 AU −1 (AU is animal unit of 500 kg) for NH 3 , CH 4 , CO 2 and N 2 O respectively.
-
Implementation of Radioactive 85Kr for Ventilation Rate Measurements in Dairy Barns
2011 Louisville Kentucky August 7 - August 10 2011, 2011Co-Authors: Mohamed Samer, Werner Berg, Christiane Löbsin, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, Olaf Tober, P. Sanftleben, Reiner BrunschAbstract:Quantifying gaseous emissions from naturally ventilated animal buildings is a particularly difficult task and associated with large uncertainties. One aspect is to measure the ventilation rate and then to quantify the gaseous emissions. Therefore, the ventilation rate was determined by two methods, simultaneously. Fifteen field experiments were carried out to study the ventilation rate in a naturally ventilated dairy barn located in Northern Germany during three consecutive winter seasons. The air exchange rates and then the ventilation rates were determined by the decay of the radioactive tracer Krypton-85, and the carbon dioxide (CO2) balance which is the reference method. Afterwards, the results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. During each field experiment, continuous measurements of gas concentrations (NH3, CO2, CH4, and N2O) inside and outside the building and 85Kr tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The tracer gas technique was further developed for better application through winter measurements. Where, eight combination factors were tested which are: 85Kr line release source vs. 85Kr point release source, average a-values vs. sum impulses, selected Radiation Counters vs. all Radiation Counters. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O respectively.
-
Winter Measurements of Air Exchange Rates Using Tracer Gas Technique and Quantification of Gaseous Emissions from a Naturally Ventilated Dairy Barn
Applied Engineering in Agriculture, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Measuring the ventilation rates and then quantifying the gaseous emissions from naturally ventilated barns is a particularly difficult task and associated with large uncertainties; where no accurate, reliable, and online method is available for ventilation rate measurements. Therefore, the objective of this study was to develop further the tracer gas technique (TG) for ventilation rate measurements through winter seasons. Fifteen field experiments were carried out to study the ventilation rates in a naturally ventilated dairy barn located in North Germany through three consecutive winter seasons. During each field experiment, continuous measurements of gaseous concentrations (NH3, CO2, CH4, and N2O) inside and outside the barn and tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The air exchange rates (AERs) and then the ventilation rates were estimated by the TG and the CO2-balance which was set as reference method, in this study, for the purpose of statistical analysis. Three factors with two levels each were tested and they are: 85Kr point release source versus 85Kr line release source, average a-values versus sum impulses, selected Radiation Counters versus all Radiation Counters; resulting in eight factor combinations. The results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O, respectively.
Reiner Zorn - One of the best experts on this subject based on the ideXlab platform.
-
Optimization of step‐scanning registration with Radiation Counters
Review of Scientific Instruments, 1995Co-Authors: Reiner ZornAbstract:If an intensity distribution of Radiation (x‐rays, neutrons, etc.) is scanned by a movable counterdetector, the step‐scanning method is used often. The detector stops at certain positions of the region to be scanned and is left there at rest for the time of counting. Then the experimentalist has to decide where to set these positions, especially how dense the scan should be. This decision is usually done by ‘‘rule of thumb.’’ In this article an optimization method will be described which uses calculus of variation to determine the registration positions (at least their density) on an objective basis. To do this, the statistical error and the error due to coarse scanning will be considered together in a figure of merit which has to be minimized. The main result is that the density of steps is proportional to the 2/5th power of the second derivative of the intensity distribution. This reflects the customary design principle, to scan regions with ‘‘more structure’’ more densely. In short an application of th...
-
optimization of step scanning registration with Radiation Counters
Review of Scientific Instruments, 1995Co-Authors: Reiner ZornAbstract:If an intensity distribution of Radiation (x‐rays, neutrons, etc.) is scanned by a movable counterdetector, the step‐scanning method is used often. The detector stops at certain positions of the region to be scanned and is left there at rest for the time of counting. Then the experimentalist has to decide where to set these positions, especially how dense the scan should be. This decision is usually done by ‘‘rule of thumb.’’ In this article an optimization method will be described which uses calculus of variation to determine the registration positions (at least their density) on an objective basis. To do this, the statistical error and the error due to coarse scanning will be considered together in a figure of merit which has to be minimized. The main result is that the density of steps is proportional to the 2/5th power of the second derivative of the intensity distribution. This reflects the customary design principle, to scan regions with ‘‘more structure’’ more densely. In short an application of the method on x‐ray diffraction in the low angle regime will be reported.
-
Optimization of step‐scanning registration with Radiation Counters
Review of Scientific Instruments, 1995Co-Authors: Reiner ZornAbstract:If an intensity distribution of Radiation (x‐rays, neutrons, etc.) is scanned by a movable counterdetector, the step‐scanning method is used often. The detector stops at certain positions of the region to be scanned and is left there at rest for the time of counting. Then the experimentalist has to decide where to set these positions, especially how dense the scan should be. This decision is usually done by ‘‘rule of thumb.’’ In this article an optimization method will be described which uses calculus of variation to determine the registration positions (at least their density) on an objective basis. To do this, the statistical error and the error due to coarse scanning will be considered together in a figure of merit which has to be minimized. The main result is that the density of steps is proportional to the 2/5th power of the second derivative of the intensity distribution. This reflects the customary design principle, to scan regions with ‘‘more structure’’ more densely. In short an application of the method on x‐ray diffraction in the low angle regime will be reported.
Werner Berg - One of the best experts on this subject based on the ideXlab platform.
-
Developing the 85Kr tracer gas technique for air exchange rate measurements in naturally ventilated animal buildings
Biosystems Engineering, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Experiments were performed to study air exchange rates (AER) occurring in naturally ventilated dairy buildings during summer seasons 2006 to 2010. A tracer gas technique (TG) for AER measurements was developed. The AERs were determined by decay of radioactive tracer Krypton-85, and CO 2 -balance used as the reference method (RM). During each experiment, continuous measurements of gaseous concentrations (NH 3 , CO 2 , CH 4 and N 2 O) inside and outside the building and 85 Kr tracer gas experiments were performed. The combined factors investigated were release over feeding table (a 1 ) or over the manure alley (a 2 ), average α-values (b 1 ) or the sum of impulses (b 2 ), selected Radiation counts (c 1 ) or all Radiation counts (c 2 ). The results were compared using Pearson correlation analysis, developing a linear regression model, and testing the differences between the factor combinations and the RM using an ANOVA model. There were differences between impulses (Pr > |t| = 0.0013), where the sum of impulses showed better results than the average α-values. Although there was no difference (Pr > |t| = 0.344) between the readings of the Radiation counts, it was considered that by using all the readings of the Radiation Counters it was more representative and easier to calculate the AER. The best factor combinations, having the highest coefficient of determination values R 2 , and the most reliable parameter estimates, were: a 1 b 2 c 2 ( R 2 = 0.94; 1.63 ± 0.14); and a 1 b 1 c 1 ( R 2 = 0.97; 2.03 ± 0.11). The gaseous emissions, subject to the RM, were 3.9, 19, 1656, and 0.96 g h −1 AU −1 (AU is animal unit of 500 kg) for NH 3 , CH 4 , CO 2 and N 2 O respectively.
-
Implementation of Radioactive 85Kr for Ventilation Rate Measurements in Dairy Barns
2011 Louisville Kentucky August 7 - August 10 2011, 2011Co-Authors: Mohamed Samer, Werner Berg, Christiane Löbsin, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, Olaf Tober, P. Sanftleben, Reiner BrunschAbstract:Quantifying gaseous emissions from naturally ventilated animal buildings is a particularly difficult task and associated with large uncertainties. One aspect is to measure the ventilation rate and then to quantify the gaseous emissions. Therefore, the ventilation rate was determined by two methods, simultaneously. Fifteen field experiments were carried out to study the ventilation rate in a naturally ventilated dairy barn located in Northern Germany during three consecutive winter seasons. The air exchange rates and then the ventilation rates were determined by the decay of the radioactive tracer Krypton-85, and the carbon dioxide (CO2) balance which is the reference method. Afterwards, the results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. During each field experiment, continuous measurements of gas concentrations (NH3, CO2, CH4, and N2O) inside and outside the building and 85Kr tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The tracer gas technique was further developed for better application through winter measurements. Where, eight combination factors were tested which are: 85Kr line release source vs. 85Kr point release source, average a-values vs. sum impulses, selected Radiation Counters vs. all Radiation Counters. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O respectively.
-
Winter Measurements of Air Exchange Rates Using Tracer Gas Technique and Quantification of Gaseous Emissions from a Naturally Ventilated Dairy Barn
Applied Engineering in Agriculture, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Measuring the ventilation rates and then quantifying the gaseous emissions from naturally ventilated barns is a particularly difficult task and associated with large uncertainties; where no accurate, reliable, and online method is available for ventilation rate measurements. Therefore, the objective of this study was to develop further the tracer gas technique (TG) for ventilation rate measurements through winter seasons. Fifteen field experiments were carried out to study the ventilation rates in a naturally ventilated dairy barn located in North Germany through three consecutive winter seasons. During each field experiment, continuous measurements of gaseous concentrations (NH3, CO2, CH4, and N2O) inside and outside the barn and tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The air exchange rates (AERs) and then the ventilation rates were estimated by the TG and the CO2-balance which was set as reference method, in this study, for the purpose of statistical analysis. Three factors with two levels each were tested and they are: 85Kr point release source versus 85Kr line release source, average a-values versus sum impulses, selected Radiation Counters versus all Radiation Counters; resulting in eight factor combinations. The results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O, respectively.
Merike Fiedler - One of the best experts on this subject based on the ideXlab platform.
-
Developing the 85Kr tracer gas technique for air exchange rate measurements in naturally ventilated animal buildings
Biosystems Engineering, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Experiments were performed to study air exchange rates (AER) occurring in naturally ventilated dairy buildings during summer seasons 2006 to 2010. A tracer gas technique (TG) for AER measurements was developed. The AERs were determined by decay of radioactive tracer Krypton-85, and CO 2 -balance used as the reference method (RM). During each experiment, continuous measurements of gaseous concentrations (NH 3 , CO 2 , CH 4 and N 2 O) inside and outside the building and 85 Kr tracer gas experiments were performed. The combined factors investigated were release over feeding table (a 1 ) or over the manure alley (a 2 ), average α-values (b 1 ) or the sum of impulses (b 2 ), selected Radiation counts (c 1 ) or all Radiation counts (c 2 ). The results were compared using Pearson correlation analysis, developing a linear regression model, and testing the differences between the factor combinations and the RM using an ANOVA model. There were differences between impulses (Pr > |t| = 0.0013), where the sum of impulses showed better results than the average α-values. Although there was no difference (Pr > |t| = 0.344) between the readings of the Radiation counts, it was considered that by using all the readings of the Radiation Counters it was more representative and easier to calculate the AER. The best factor combinations, having the highest coefficient of determination values R 2 , and the most reliable parameter estimates, were: a 1 b 2 c 2 ( R 2 = 0.94; 1.63 ± 0.14); and a 1 b 1 c 1 ( R 2 = 0.97; 2.03 ± 0.11). The gaseous emissions, subject to the RM, were 3.9, 19, 1656, and 0.96 g h −1 AU −1 (AU is animal unit of 500 kg) for NH 3 , CH 4 , CO 2 and N 2 O respectively.
-
Implementation of Radioactive 85Kr for Ventilation Rate Measurements in Dairy Barns
2011 Louisville Kentucky August 7 - August 10 2011, 2011Co-Authors: Mohamed Samer, Werner Berg, Christiane Löbsin, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, Olaf Tober, P. Sanftleben, Reiner BrunschAbstract:Quantifying gaseous emissions from naturally ventilated animal buildings is a particularly difficult task and associated with large uncertainties. One aspect is to measure the ventilation rate and then to quantify the gaseous emissions. Therefore, the ventilation rate was determined by two methods, simultaneously. Fifteen field experiments were carried out to study the ventilation rate in a naturally ventilated dairy barn located in Northern Germany during three consecutive winter seasons. The air exchange rates and then the ventilation rates were determined by the decay of the radioactive tracer Krypton-85, and the carbon dioxide (CO2) balance which is the reference method. Afterwards, the results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. During each field experiment, continuous measurements of gas concentrations (NH3, CO2, CH4, and N2O) inside and outside the building and 85Kr tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The tracer gas technique was further developed for better application through winter measurements. Where, eight combination factors were tested which are: 85Kr line release source vs. 85Kr point release source, average a-values vs. sum impulses, selected Radiation Counters vs. all Radiation Counters. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O respectively.
-
Winter Measurements of Air Exchange Rates Using Tracer Gas Technique and Quantification of Gaseous Emissions from a Naturally Ventilated Dairy Barn
Applied Engineering in Agriculture, 2011Co-Authors: Mohamed Samer, Werner Berg, Merike Fiedler, Hans-joachim Müller, Manfred Gläser, Christian Ammon, P. Sanftleben, Reiner BrunschAbstract:Measuring the ventilation rates and then quantifying the gaseous emissions from naturally ventilated barns is a particularly difficult task and associated with large uncertainties; where no accurate, reliable, and online method is available for ventilation rate measurements. Therefore, the objective of this study was to develop further the tracer gas technique (TG) for ventilation rate measurements through winter seasons. Fifteen field experiments were carried out to study the ventilation rates in a naturally ventilated dairy barn located in North Germany through three consecutive winter seasons. During each field experiment, continuous measurements of gaseous concentrations (NH3, CO2, CH4, and N2O) inside and outside the barn and tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The air exchange rates (AERs) and then the ventilation rates were estimated by the TG and the CO2-balance which was set as reference method, in this study, for the purpose of statistical analysis. Three factors with two levels each were tested and they are: 85Kr point release source versus 85Kr line release source, average a-values versus sum impulses, selected Radiation Counters versus all Radiation Counters; resulting in eight factor combinations. The results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all Radiation Counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O, respectively.
