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Design of biofilters
Published in Joseph S. Devinny, Marc A. Deshusses, Todd S. Webster, Biofiltration for Air Pollution Control, 2017
Joseph S. Devinny, Marc A. Deshusses, Todd S. Webster
Various operating parameters can be measured using commercially available instruments (see Chapter 8 for further details). For the measurement of gas- phase concentrations, continuous gas monitoring equipment is best, but expensive. Gas chromatography (GC) is generally the simplest method for vapor analysis. A flame ionization detector (FID) can be used to measure total and specific hydrocarbon concentrations. A photoionization detector (PID) is effective in measuring organic and inorganic compound concentrations. Chlorinated compound analysis can be accomplished using a direct electrolytic conductivity detector (DELCD) or an electron capture detector (ECD). For odor measurements, an olfactometer may be used. For all gas samples, analysis may be performed on-line or grab samples may be taken in non-reactive sampling bags or stainless steel canisters and injected into a GC. For on-line sampling, care must be taken to prevent moisture from condensing in the sample lines. This may be accomplished by warming the lines with heating tape, by using appropriate membrane filters, or by periodically backflushing the lines with ambient air.
Temperature, relative humidity, noise, dust and odor levels recorded on free-range piggery sites in three states of Australia
Published in Thomas Banhazi, Andres Aland, Jörg Hartung, Air Quality and Livestock Farming, 2018
The NATA-accredited odor laboratories operate by the Australian Standard for odor measurement “Determination of odor concentration by dynamic olfactometry” (AS/NZS 4323.3:2001), which prescribes a method for sample analysis that provides quality assurance/quality control and ensures a high degree of confidence in the accuracy, repeatability and reproducibility of results. The concentration of an odor can be measured using a technique known as forced-choice dynamic olfactometry. Dynamic olfactometry involves the repeated presentation of both a diluted odor sample and an odor-free air stream to a panel of qualified assessors through two adjacent ports on the olfactometer. Four to six trained assessors (“panelists”) for sample analyses were utilized with the results from four qualified panelists being the minimum allowed under the Australian Standard AS/NZS 4323.3:2001. The method for odor concentration analysis involved the odorous gas sample initially being diluted to the point where any member of the panel cannot detect it. Each panelist stepped up to the olfactometer in turn to take a sniff from each port, and then chose which port contains the odor and entered their response. At each stage of the testing process, the concentration of the odorous gas was systematically increased (doubled) and then re-presented to the panelists. A round was completed when all assessors correctly detected the presence of the odor with certainty. The odor was presented to the panel for three rounds, and the results were taken from the latter two rounds, as prescribed in AS/NZS 4323.3:2001. The samples collected in this study at the VIC and NSW farms were tested on the day of their collection. The odor panels also characterized the odor samples and assessed the “hedonic tone.”
Wood Fiber Reinforced Thermoplastic and Thermosets Composites
Published in Omar Faruk , Jimi Tjong , Mohini Sain, Lightweight and Sustainable Materials for Automotive Applications, 2017
Sensorial methods to gauge odors are olfactometry and electronic noses. With olfactometry, odor concentration, strength of odor reception, and hedonic impression (judged as pleasant or unpleasant) are determined (Bledzki et al. 2003). The olfactometer is a dilution apparatus that mixes odorous air in specific ratios with odor-free air for presentation to a panel of assessing persons. Electronic noses are highly developed sensors, gas sensor arrays, which produce digital fingerprints of scents. These sensors detect gases and classify them by comparison with stored data.
A multimodal MR-compatible olfactometer with real-time controlling capability
Published in Journal of Medical Engineering & Technology, 2020
Seyedeh Fahimeh Hosseini, Seyed Kamran Kamrava, Somayeh Asadi, Shayan Maleki, Arash Zare-Sadeghi, Ali Shakeri-Zadeh
The olfactometers require to have unique properties for applying in the fMRI scanning session. The most essential is the absence of ferrous. Considering the limitations of construction in available odour-delivery apparatus, as well as their relatively high cost, we designed an eight channel MR-compatible olfactometer. We used a simple design which prevents odour adherence within the air pathways. Here, we report our designed olfactometer with some properties include in (1) continuous diluent airflow; (2) capability in selection of stimulus and stimulus concentration; (3) effective delivery of different odours; (4) presentation of an odour stimulus of selectable and reliable duration in a constant airflow, with no additional type of subordinate stimulation; (5) resistance to contamination; (6) durability; (7) the convenience of operating, refilling, and cleaning; (8) low cost; (9) equipped with computer control system; and (10) rapid delivery and removal of the odour stimulus. The priority of our design to previous constructions is a more rapid delivery system and resistance to odour contamination. The olfactometer described here meet all over-mentioned requirements and may have appropriate applications in different experimental settings. To evaluate the capability of the olfactometer to stimulate the brain olfactory system, we designed a task-based fMRI experiment. Then, the applicability of our design was demonstrated by fMRI data analysis. Workflow diagram of the current study is presented in Figure 1(a).