• Journal of Biosystems Engineering
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• 제28권5호
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• pp.469-482
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• 2003

• Journal of Oral Medicine and Pain
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• 제26권4호
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• pp.309-318
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• 2001

The purposes of the study were (1) to evaluate the olfactory identification ability in those who have bad breath, (2) to determine the olfactory detection threshold for methyl mercaptan in normal subjects and those who have bad breath, and (3) to evaluate the effect of oral hygiene care on the olfactory detection threshold for methyl mercaptan. Sixteen male subjects with bad breath (male odor group), 9 male subjects without bad breath (male non-odor group), and 10 female subjects without bad breath (female non-odor group) were included for the study. Olfactory identification ability was assessed by administrating the Cross-Cultural Smell Identification Test (CC-SIT), and the olfactory detection threshold for methyl mercaptan was measured by two-alternative forced-choice single-staircase detection threshold procedure in a double-blinded condition. The geometric mean of the last four staircase reversal points of a total of seven reversals is used as the threshold. For the male odor group, after 1 month of intensive oral hygiene care for reducing oral volatile sulfur compounds (VSC) concentration, the olfactory detection threshold for methyl mercaptan was measured again and compared to the initial value. The ANOVA was used to test the group difference of olfactory threshold and olfactory identification ability and the paired t-test was used to test the difference of olfactory threshold between before and after reduction of oral VSC in male odor group. The results were as follows : 1. There was no significant difference in olfactory identification ability among those who have bad breath and normal male or female subjects. 2. The olfactory detection threshold for methyl mercaptan was about 8.4 ppb in normal male and female. 3. There was a tendency that male subjects with bad breath showed a higher olfactory detection threshold for methyl mercaptan when compared to those of no bad breath. 4. The olfactory detection threshold for methyl mercaptan returned to a normal level after 1 month of intensive oral hygiene care for reducing oral VSC.

• 한국수산과학회지
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• 제51권5호
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• pp.499-509
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• 2018

This study optimized the bone-softening and fishy odor-reducing process for mackerel Scomber japonicus products using response surface methodology (RSM). The RSM showed that the optimum concentrations of doenjang and citric acid for reducing the fishy odor in bone-softened mackerel were 11.8% and 0.04%, respectively, and the optimum immersion time was 52.2 min. The estimated overall acceptance, salinity, and acidity of the products under these optimum conditions were 7.7 points, 1.1%, and 202.6 mg/100 g, respectively, which were similar to the actual measured values of $7.6{\pm}1.2$ points, $1.0{\pm}0.1%$ and $203.2{\pm}3.8mg/100g$. Moreover, the heating temperature and time for bone-softening based on RSM were $107.3^{\circ}C$ and 4.4 h, respectively. The estimated hardness and proportion of skin removed from the product under the optimal conditions were $161.5g/cm^2$ and 0.09%, respectively, which were also similar to the actual measured values of $171.1{\pm}12.6g/cm^2$ and $0.10{\pm}0.02%$. The optimum bone-softening and fishy odor-reducing process for mackerel consisted of the following steps: thawing (${\leq}10^{\circ}C$, 8 h), filleting, washing/dewatering, immersing in an 11.8% doenjang -0.04% citric acid solution for 52 min, washing/dewatering, heating ($107.3^{\circ}C$, 4.4 h), freezing, depanning, internal and external packaging, and X-ray detection treatment.

• 유통과학연구
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• 제19권4호
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• pp.53-60
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• 2021

Purpose: This study focuses on exploring ways to improve the distribution method of shrimp farming so that it is eco-friendly and increases the distribution of shrimp. Research design, data and methodology: The experimental device installed in a biofloc shrimp culture in one area tested 10 times. Complex odor, concentration of H2S, water quality improvement effected by decomposition of organic substances, and degree of microbial activation measured. The data of the experimental results verified using the T-test technique, and the p value was determined based on the significance probability of 0.05. Results: This experimental device was effective in reducing odor and hydrogen sulfide in shrimp farms. With the improvement of water quality, dissolved oxygen increased due to the microbubble and cavitation action of air ejector and ultrasonic waves. In addition, the cultured microorganisms in the cultured water treated by the experimental device were remarkably proliferated compared to the raw water. Conclusions: The biofloc distribution method has a significant effect on improving water quality and reducing odor substances and will become a new eco-friendly and efficient distribution method for shrimp farming in the future.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2010년도 춘계학술대회 논문집
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• pp.521-523
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• 2010

• 한국환경과학회지
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• 제15권6호
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• pp.563-569
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• 2006

It was compared the reduction effect of contaminants and odor according to DO change and EM (effective microorganisms) addition in maturation process of piggery slurry. The maturation processes were divided into three cases as follows: R-1 was operated at $2.5mg/{\ell}$ of DO without the addition of EM, R-2 was operated at $7.5mg/{\ell}$ of DO without the addition of EM and R-3 was operated at $2.5mg/{\ell}$ of DO with the addition of EM. The addition of EM was more effective than the increase of DO for the reduction of CODcr, $NH_3-N$ and T-N in the maturation of piggery slurry. In addition, the reducing effect of odor intensity appeared high even in the short-term maturation period in case of adding EM and one could not even smell the stimulating odor of piggery slurry.

• Animal Bioscience
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• 제36권10호
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• pp.1584-1595
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• 2023

Objective: This study was conducted to evaluate the effect of a low-protein diet on growth performance, carcass traits, nutrient digestibility, blood profiles, and odor emissions in growing-finishing pigs. Methods: A total of 126 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 38.56±0.53 kg were used for a 14-week feeding trial. Experimental pigs were allotted to one of 6 treatments in 3 replicates of 7 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with different levels of crude protein (CP). Phase 1 (early growing): 14%, 15%, 16%, 17%, 18%, 19%; phase 2 (late growing): 13%, 14%, 15%, 16%, 17%, 18%; phase 3 (early finishing): 12%, 13%, 14%, 15%, 16%, 17%; phase 4 (late finishing): 11%, 12%, 13%, 14%, 15%, 16%. All experimental diets in each phase were contained the same concentration of lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp). Results: Over the entire experimental period, there was no significant difference in BW, average daily feed intake, and gain-to-feed ratio among all treatments (p>0.05), but a quadratic effect (p = 0.04) was observed in average daily gain (ADG) during the late finishing phase with higher ADG in Group D. Blood urea nitrogen concentration linearly increased with an increase in dietary CP levels (p<0.01). Regarding nutrient digestibility, excreted nitrogen in urine and feces and nitrogen retention linearly increased as the CP level increased (p<0.01). A linear effect was observed with increasing CP levels in amines, ammonia, and hydrogen sulfide in odor emissions (p<0.01). No significant effects were observed in the measurements of carcass traits and meat characteristics (p>0.05). Conclusion: In phase feeding, reducing the CP level to 14% in early-growing pigs, 13% in late-growing pigs, 12% in early-finishing pigs, and 11% in late-finishing pigs is recommended.

• 산경연구논집
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• 제9권12호
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• pp.23-29
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• 2018

Purpose - The purpose of this study is to apply a cost effective ultrasonic odor reduction method that generated micro-bubbles using ejector to the Southeast Asian wastewater market. Research design, data, and methodology - A leather maker located in Ansan-city, Gyunggi-do, South Korea was sampled from the collection tank to select experimental materials. Experimental setup consisted of circulating water tank-air ejector-ultrasonic device, and circulating wastewater. Sample analysis was performed by CODcr, T-N, T-P, and turbidity by the National Environmental Science Institute. Results - Experimental results show that it is most effective in removing odors when the frequency range of ultrasonic wave is 60~80 Khz and the output is 200 W. It showed that the concentration of complex odor dropped from a maximum of 14,422 times to a minimum of 120 times. Also, analysis of ammonia and hydrogen sulfide in specific odor substances has shown that they were reduced from 1.5 ppm to 0.4 ppm and from 0.6 ppm to 0.1 ppm, respectively. Conclusions - It is possible to shorten more than 12 hours in the treatment of micro-organisms. It can be seen that the processing time of odor after ultrasonic treatment in the pre-treatment facility is reduced by 25% when compared to the resultant micro-organisms after the chemical treatment, that is, the time of the bio-treatment of micro-organisms. Based on the results, it was confirmed that the pre-treatment method using the ultrasonic and the air ejector device of the experiment shows the effect of reducing the water pollutants and odor more effectively in a relatively short time than the conventional advanced oxidation method.

• 한국환경과학회지
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• 제20권8호
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• pp.953-962
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• 2011

The covered stream of cities are considered an odor source. Also, the public do not want a wastewater treatment plant(WWTP) near their properties due to the emission of odor emanating from such sources, although they play an important role in urban development. The purpose of this study is to analyze the pattern distribution of the odorous compounds from the Nambu WWTP and Youngho stream in Busan. odor sampled four times were analyzed by instrumental analysis method and indirect olfactory method. The kinds of offensive odorous compounds examined are acetaldehyde, propion aldehyde, hydrogen sulfide, methyl mercaptan, dimethyl sulfide and ammonia. Also, Concentration of air pollutants has been calculated by ISCST3 models. At the result of this study, The Nambu WWTP releases sulfur compounds. And the major odorous were hydrogen sulfide (1,475 ppb) and acetaldehyde (95 ppb) at Youngho stream. The stink which residents feel will point out the Nambu WWTP mainly if the odor is removed with the improvement of a Youngho stream. Accordingly, we should pay more attention to appropriate components to processes in odor reducing plan at Nambu WWTP.

• 한국환경과학회지
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• 제33권8호
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• pp.575-581
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• 2024

Insect pests are a significant threat to stored crops and can lead to considerable economic losses and reduced crop quality. Traditional pest control methods often involve chemical treatments, which have adverse environmental and health effects. This study evaluated the effectiveness of controlling the environment using LED lighting and plant-derived odor barriers as a dual strategy for insect pest control. The storage environment was altered using LED lights that emitted specific wavelengths (580-585 nm) and by reducing other wavelengths (300-500 nm). This light environment was combined with an insect odor barrier derived from Cinnamomum verum, Illicium verum, and Artemisia annua, and their duel impact on the behavior and frequency of insect pests under real storage conditions was determined. The findings revealed significant changes in the frequencies of various insect orders, indicating differential responses to light wavelengths and odor barriers. Notably, the introduction of an anti-insect light and odor barrier environment reduced Diptera and Hemiptera frequencies, which could potentially reduce pest intrusion. The results underscore the potential use of integrated light and odor barriers as a noninvasive and environmentally friendly approach to pest management. This study identifies the specific wavelengths and odor combinations that effectively deter insect pests and contribute to the development of more efficient and sustainable pest control methods. It also highlights the importance of understanding insect behavior and frequency changes in response to novel deterrent strategies.