Triangle Odor Bag Method Research Articles

Five Typical Stenches Detection Using an Electronic Nose.

This paper deals with the classification of stenches, which can stimulate olfactory organs to discomfort people and pollute the environment. In China, the triangle odor bag method, which only depends on the state of the panelist, is widely used in determining odor concentration. In this paper, we propose a stenches detection system composed of an electronic nose and machine learning algorithms to discriminate five typical stenches. These five chemicals producing stenches are 2-phenylethyl alcohol, isovaleric acid, methylcyclopentanone, γ-undecalactone, and 2-methylindole. We will use random forest, support vector machines, backpropagation neural network, principal components analysis (PCA), and linear discriminant analysis (LDA) in this paper. The result shows that LDA (support vector machine (SVM)) has better performance in detecting the stenches considered in this paper.

Experimental Verification on Effect of Suction method on Measurement Threshold Value of Triangle Odor Bag Method

Experimental Verification on Effect of Suction method on Measurement Threshold Value of Triangle Odor Bag Method

三点比較式臭袋法における吸入濃度に基づく最適吸引法に関する研究 （その９）顔および鼻腔の詳細モデルを用いた検臭臭気の吸引濃度評価

三点比較式臭袋法における吸入濃度に基づく最適吸引法に関する研究 （その９）顔および鼻腔の詳細モデルを用いた検臭臭気の吸引濃度評価

Basic Study of Suction-odor Concentration in Triangle Odor Bag Method by Computational Fluid Dynamics Part.2 Case studies of Suction-odor Concentration in the Discharge and Suction Method

Basic Study of Suction-odor Concentration in Triangle Odor Bag Method by Computational Fluid Dynamics Part.2 Case studies of Suction-odor Concentration in the Discharge and Suction Method

Stench Sources and Impact Analysis in Automobile Making

Volatile organic compounds (VOCs) are an important source of industrial stench. This study was aimed at sampling and analyzing the stench source and its impact on the sensitive spot residential areas, concentrating on certain automobile manufacturing enterprise. The odor concentration and VOCs species of each vent stack, plant boundary, and sensitive spot in the enterprise were determined for November 15 and 17, 2016 via qualitative and quantitative analysis using the triangle odor bag method and gas pre-concentration system-gas chromatography-mass spectra. The results show that the odor concentrations of all vent stacks in the original equipment manufacturing plant and the engine plant were below the criterion level, those of the plant boundaries in the engine plant were below the limits, and those of the plant boundaries and sensitive spots in the original equipment manufacturing plant exceeded the allowed standards. A total of 54 VOCs species were identified, including aromatics, halogenated compounds, alkanes, alkene, cycloalkanes, ketones, esters, ethers, alcohols, sulfur compounds, and oxygen ring compounds. Halogenated compounds were the most abundant VOCs species, followed by aromatics. As a result, aromatics and halogenated compounds are the representative odorants in automobile making. 1,3-Butadiene and ethyl toluene were selected to be the typical odorants of sensitive spots according to mass concentration, detector odor threshold, and threshold dilution multiples of characteristic VOCs species in sensitive spots. The results show that the majority of characteristic VOCs species were from paint composition through the qualitative analysis based on paint used in coating shops. 1,3-Butadiene, which contributed the most to odor pollution, excluding the impact of other emission sources on sensitive spots, originates from spraying and drying processes of coating shops in the original equipment manufacturer. It is recommended that the enterprise should adopt environmentally friendly paints with low VOCs components or RTO purification equipment with higher processing efficiency to reduce the impact of stench on the sensitive residential areas from automobile making.

三点比較式臭袋法における吸入濃度に基づく最適吸引法に関する研究 （その２）簡易CFD 解析に基づく吸引濃度予測

三点比較式臭袋法における吸入濃度に基づく最適吸引法に関する研究 （その２）簡易CFD 解析に基づく吸引濃度予測

Basic Study of Suction-odor Concentration in Triangle Odor Bag Method by Computational Fluid Dynamics

Basic Study of Suction-odor Concentration in Triangle Odor Bag Method by Computational Fluid Dynamics

The Interaction of Mixing Odorants with Similar Chemical Properties: A Case Study on Ketone Compounds

To investigate more about the interaction of mixing odorants, a series of sensory tests were conducted using five ketones [butanone (Bu), 2-Pentanone (Pe), 2-Hexanone (Hex), 2-Heptanone (Hep), 2-Octanone (Oc)] at varying concentration levels. The determination of odor threshold (OT) was initially conducted by the triangle odor bag method (GB/T 14675, China). The odor activity values (OAVs) of individual odorants at a wide range of concentrations were derived from concentration-to-odor threshold ratios. The resulting data were then evaluated to define the empirical relationship for each ketone between the OAV and odor intensity (OI) scaling. Based on the relationships defined for each individual ketone, the OI values were estimated for a synthetic mixture of five ketones. The effect of mixing was then examined by assessing those estimated OI values with the actually measured OI values. The overall results of this study confirmed that the OI values of the synthetic mixture is not governed by the common theoretical basis (e.g., rule of additivity, synergism, or a stronger component model) but is best represented by the averaged contribution of all ketone components. Thus, the odor intensity (OI) of a given mixture sample containing odorants with similar chemical properties can be accessed through the conversion from its concentration value with the application of empirical equations instead of direct measurement by the human test panel.

Relationship between the Differences of Odor Detection Threshold Values Measured by Different Methods and some of the Physicochemical Properties

The amount of sample can enter the nasal cavity depends on the physiochemical characteristics such as distribution, volatility and solubility. It can be suspected that the difference of odor detection threshold (ODT) measured by different methods is related to the physicochemical properties of compounds. To investigate the relationship between ODT differences and the physicochemical properties of compounds, ODT values of four series of organic compounds were measured by triangle odor bag method and gas chromatography and olfactometry method; the results were compared and the absolute differences were calculated. Relationship between ODT differences and the type of functional group and some of the physicochemical properties of compounds was analyzed. The results showed the type of functional group had significant effect on the differences. Certain linear relationships between the logarithmic value of differences and the logarithmic values of saturated vapor pressure and molecular weight were observed.

三点比較式臭袋法はどのようにして作られたか

三点比較式臭袋法はどのようにして作られたか

A new method for measuring odors by triangle odor bag method (I)

A new method for measuring odors by triangle odor bag method (I)

The Examination of the Precision of Triangle Odor Bag Method by Computer Simulation

The Examination of the Precision of Triangle Odor Bag Method by Computer Simulation

COMPARISON BETWEEN RESIDENTS AND PANEL ON SENSORY EVALUATION OF STATIONARY ODOR

The purposes of this study are to confirm the lowest level of odor in the living-dining rooms with kitchen (LDKs) and to examine the difference between residents and panel on the odor evaluations. Odor samples for olfactory measurements were collected in LDKs of 40 by residents. We measured odor concentration of odor samples by the triangle odor bag method. In addition odor intensity, odor hedonics, and odor quality of odor samples were evaluated by panel and residents. The odor concentration showed 10 - 1700 and the average was 70. The measurement values of 9 LDKs were higher than the outdoor regulation standard. On the 6-step odor intensity, the average of panel was 3.2 and the average of residents was 0.4. On the 9-step odor hedonics, the average of panel was -1.4 and the average of residents was 1.6. The difference between residents and panel for the intensity and the odor hedonics was about 3 steps.

Analysis and removal of the stench emitted from indoor dust

The offensive odor produced from indoor dust accumulated inside a vacuum cleaner is quite unpleasant to the user. In this study, the odor of dust samples prepared under various conditions was examined using an olfactory method that employs the human sense of smell. In addition, the odorous compounds were analyzed by GC-MS. The odor intensity of the dust collected inside the vacuum cleaner increased in proportion to not only the humidity and temperature of the dust, but also to the cleaning period of the container where indoor dust was accumulated. GC/MS confirmed aldehydes to be the main odorous compounds. The dilution ratio at which the stench of the indoor dust was not detected was determined by using the triangle odor bag method.

CFD ANALYSIS OF INDOOR ODOR FROM FOOD USING THE RESULT OF OLFACTORY EXPERIMENT

Recently, complaints about indoor odors due to over-airtightness by residents living in high-rise residential building have been increasing. In this study, the odor dispersion from food in a house was estimated using CFD simulation by the result of an olfactory experiment as the first step to find countermeasures to reduce the influence on residents of the dispersion of indoor odors from food. As a representative Korean food for its strong smell, Cheonggukjang was used as the source. The threshold of the source was measured by an olfactory experiment using the triangle odor bag method and the flux rate of the source was calculated. Subsequently a steady-state CFD simulation for a unit model of a Korean high-rise residential building was carried out to evaluate the ventilation performance and the odor dispersion was estimated using the flux rate from the olfactory experiment. A new system for removing the indoor odor was considered as a measure for odor dispersion and evaluated using CFD simulation. This method could be applied for identifying and solving common odor problems not just the specific case.

Key odor components responsible for the impact on olfactory sense during swine feces composting

This study aimed to identify the major odor contributing components produced during swine feces composting which have an impact on the olfactory senses. A total of 64 gas samples collected at different stages of composting were analyzed by both a gas chromatograph and human panel test using the triangle odor bag method. Multiple regression analysis of representative odor substances present in the outlet gas was carried out employing the odor index (OI) as the dependent variable and the odor unit as the independent variable. The recorded changes in OI indicated that turning was an important event during odor evolution, and that the odor emission during the thermophilic phase should be the main target for odor abatement. The model incorporating ammonia, methyl mercaptan and dimethyl sulfide as independent variables confirmed the value of the OI ( R 2 = 0.70). These compounds were identified to be the key odor components significantly determining the OI.

Difference in the odor concentrations measured by the triangle odor bag method and dynamic olfactometry

'The triangle odor bag method', which has been adopted for the offensive odor control law in Japan, and the dynamic olfactometry defined by EN 13725 have been compared. The odor concentration measured by the triangle odor bag method tends to be higher than that of the dynamic olfactometry in the forced choice mode, while well agreed in the Yes/No mode olfactometry when the panel is the same. The difference can be minimized by applying the panel selection criterion of EN13725 to the triangle odor bag method. The European panel selection test is useful to negate the difference in the measurement equipments although the criteria seem to be strict considering the individual threshold data of n-butanol.

Study on the Improvement of Work Environment by Photocatalyst in the Laboratory Animal Room

The presence of odorants and airborne bacterium within animal laboratories posed personal discomfort as well as health risks to researchers and their staff. This led to the development of photo-catalytic based filtration technology, capable of absorbing and decomposing odors in addition to sterilizing airborne bacterium, for an indoor air-circulation device. We performed several experiments to determine its characteristics. The result was a detection of tri-methylamine, which was found to contribute 94.6% of the odor in the laboratory animal room. Tri-methylamine is an important indicator in the odor environment for researchers and working staff. During field tests within animal laboratories, the experimental filtration system removed about 82% of the tri-methylamine and 51% of the ammonia immediately, and decreased odor concentration from 12 to 5 or less (by the triangle odor bag method), at which point no odor was perceived. The odor concentration at the outlet of the device was maintained at less than 5 during a trial period of two months. At the same time, the filtration device removed 64–95% of all airborne bacteria within the animal laboratories. In addition, the photo-catalytic filter that attained adsorptive saturation was successfully regenerated by using the photo-catalytic ability.The results of experiment demonstrated that the test device is more effective in absorbing and removing odor and bacteria in the animal laboratory rooms than similar devices. The photo-catalytic filtration system was effective for removing odor constantly being generated in the mouse animal room.

Characteristics of deodorization for malodorants in aqueous solution by sonication

A aqueous solution of malodorants (i.e., n-valeraldehyde, n-valeric- acid, 2-methylisoborneol, and trimethylamine) was exposed to 200KHz ultrasound with a power of 6.0W/<TEX>$\textrm{cm}^2$</TEX> per unit volume in a sonochemical reactor under room temperature and atmospheric pressure condition. The concentration of malodorants decreased with irradiation time, indicating pseudo-first-order kinetics. The removal efficiency of malodorants was about from 50% to 96% decomposed after 90 minutes sonication. At the deodorization, it was determined by triangle odor bag(TOB) method for odor sensory measurement, and it indicated that over 60% of relative odors were deodorized with degradation by the sonication.