• Journal of Adhesion and Interface
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• v.18 no.4
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• pp.179-182
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• 2017

Waterborne polyurethanes(WPU) based on castor oil were successfully prepared using polycaprolactone diol(PCL), castor oil(CO) and 4,4'-methylene dicyclohexyl diisocyanate($H_{12}MDI$) as soft segment part, dimethylolbutanoic acid (DMBA) as emulsifier, and trimethylamine(TEA) as neutralizer based on different molecular weight of prepolymer. The various properties such as mechanical strength and surface reforming were evaluated using UTM, contact angle, FE-SEM based on the different molecular weight of polyol. Waterborne polyurethanes based on castor oil could be considered as a promising candidate to be applied the various adhesion fields.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2001.12a
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• pp.140-151
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• 2001

This study was performed to examine a possible application of the beverage as a bad breath controlling food. To achieve this objective, methods of gas chromatography, electronic nose, sensory analysis and halimeter were used to detect reduction in odor intensities of bad breath caused by the functional beverage as well as its active ingredients. According to results of GC and electronic nose, adding green tea and champignon extracts to bad breath indicators, methylmercaptan and trimethylamine, resulted in significant reduction in headspace concentrations of two indicators. GC results revealed that headspace concentrations of 5 ug/ml of methylmercaptan and 30 ug/ml of trimethylamine added to various concentrations of two extracts were reduced up to $100\%$ after incubating mixtures at $37^{\circ}C$ for 5min. When the functional beverage was properly formulated with green tea extract, champignon extract and $\alpha$-cyclodextrin and evaluated for its deodorizing effect systematically, it also showed distinctive deodorizing activities against bad breath indicators. Conclusively, results obtained from this study might encourage introduction of a new type of bad breath control food in near future.

• Journal of the Korean Chemical Society
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• v.41 no.2
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• pp.105-112
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• 1997

The smelly nitro compounds were extracted from dried fishes by simultanous distillation and extraction, then were analyzed by GC-MS. Carbon number and order of an amine could be predicted by using retention time and equivalent chain length. Anchovy, codfish, imitation crab meat, cuttle fish, file fish, pollack, shrimp, octopus, harvest fish, and hard-shelled mussel were used for this investigation. Various smelly nitro compounds such as methylamine, acetamide, thiazole, 2-hydroxy isopropylamine, N-methyl pyrroline, piperidine, cyclohexylamine were identified, however, dimethylamine, trimethylamine, diethylamine were not detected. Principal components analysis was applied to GC-MS profiles for pattern recognition of smelly nitro compounds in dried fishes. Multivariate aspects using principal components analysis were very useful for pattern recognition of smelly components, category similarity.

• Journal of Sensor Science and Technology
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• v.22 no.4
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• pp.302-307
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• 2013

The Sb-doped $SnO_2$ nanowire network sensors were prepared by thermal evaporation of the mixtures between tin and antimony powders. Pure $SnO_2$ nanowire networks showed high sensor resistance in air ($99M{\Omega}$), similar gas responses to 4 diffferent gases (5 ppm $C_2H_5OH$, CO, $H_2$, and trimethylamine), and very sluggish recovery speed (90% recovery time > 800 s). In contrast, 2 wt% Sb-doped $SnO_2$ showed the selective detection toward $C_2H_5OH$ and trimethylamine, relatively low resistance ($176k{\Omega}$) for facile measurement, and ultrafast recovery speed (90% recovery times: 6 - 18 s). The change of gas sensing charactersitics by Sb doping was discussed in relation to gas sensing mechanism.

• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.271-276
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• 2019

Pure and 0.5, 1, 2, 5, and 10 at% of Mo-doped $Co_3O_4$ yolk-shell spheres were synthesized by ultrasonic spray pyrolysis of droplets containing Co nitrate, ammonium molybdate, and sucrose and their gas sensing characteristics to 5 ppm trimethylamine (TMA), ethanol, p-xylene, toluene, ammonia, carbon monoxide, and benzene were measured at $225-325^{\circ}C$. The sensor using pure $Co_3O_4$ yolk-shell spheres showed the highest response to p-xylene and very low response to TMA at $250^{\circ}C$, while the doping of Mo into $Co_3O_4$ tended to increase the overall responses of gas sensors. In particular, the sensor using 5 at% Mo-doped $Co_3O_4$ yolk-shell spheres exhibited the high response to TMA with low cross-responses to other interfering gases. The high response and selectivity of Mo-doped $Co_3O_4$ yolk-shell spheres to TMA are attributed to the electronic sensitization by higher valent Mo doping and acid-base interaction between TMA and Mo components.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.789-797
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• 2008

This study was conducted to investigate removal characteristics of gaseous trimethylamine(TMA) through biofilter packed with waste tire-chips. The sludge in this experiment was collected from an activated sludge operated in a wastewater treatment facility treating malodorous pollutants. The nominal amount of collected sludge was inoculated through packing materials in the filter. The removal efficiencies for varying concentrations and SVs(Space velocity) were assessed based on TMA, COD$_{Cr}$, NO$_3{^-}$-N, NO$_2{^-}$-N, NH$_4{^+}$-N and EPS(Extracellular Polymeric Substances) in leachate, since biofilter had been steady-stately operated. The influent concentration of 10 ppm of TMA was removed to approximately 95% regardless of changing SV at 120 and 180 hr$^{-1}$, but it was lowered to 80 to 90% at SV 240 hr$^{-1}$. As influent concentration was gradually increased from 5 to 55 ppm, the removal efficiencies of TMA were initially high for 95% in the range of 5 to 10 ppm, but lowered to 80% for 10 to 30 ppm. As a part of kinetic study for TMA decomposition, V$_m$(maximum substrate removal rate) and $K_s$(substrate infinity coefficient) were 14.3 g$\cdot$m$^{-3}$$\cdot$h$^{-1}$ and 0.043 g$\cdot$m$^{-3}$, respectively while adapted period was shown in the range of 100 to 150 hr. Also, the EPS concentration was consistently observed from the leachate showing 100 to 200 ppm, which indicates that biofilm has been continuously formed and sustained throughout tire-chips packed reactor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.245-253
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• 1979

Trimethylamine and dimethylamine contents of salted, hot-air dried, sun dried and boiled-dried samples of three commercial fishes, common mackerel, gizzard-shad and sardine, were analyzed and quantitatively compared at two different temperature conditions. The formation of both secondary amines was more rapid at $25^{\circ}C$ than at $10^{\circ}C$. And the content of dimethylamine in small sardine was comparatively higher than that in the other samples at both temperatures. Residual amounts of trimethylamine oxide of Halted common mackerel, gizzard-shad and boiled-dried small sardine were relatively higher than those of the other samples. Trimethylamine contents of sun dried samples were relatively higher than in the other samples, while those of boiled-dried small sardine was comparatively lower than those of the others. Dimethylamine content of sun dried samples were higher than those of the other samples, whereas those of boiled-dried small sardine and salted common mackerel were comparatively lower than those of the other samples.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1111-1118
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• 1996

The extracts of toha, a kind of freshwater shrimp (Caridina denticulata denticulata) being cultivated in Naju district, Chonnam of Korea and jeotsaeu, a kind of seawater shrimp (Acetes japonicus) being caught in Shinan district, Chonnam of Korea, were analyzed for the taste constituents-extractive nitrogen, free amino acids, oligopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds-using specimens collected from December in 1994 to November in 1995. The content of extractive nitrogen. free amino acids, oligopeptides, nucleotides and related compounds in toha extract was higher than that in jeotsaeu extract. On the contrary, the amount of homarine, trimethylamine oxide and trimethlamine in toha extract was lower than that in jeotsaeu extract. But in case of creatine and creatine both species showed almost the same level. Arginine, lysine, glutamine, glutamic acid, phenylalanine, leucine, alanine, asparagine and glycine were the major amino acids in toha extract, while arginine, glutamic acid, proline, glutamine, lysine, leucine, glycine, alanine and taurine were the major amino acids in jeotsaeu extract. Methionine, glutamine, valine were almost the same level between the two species. As for nucleotides and related compound, AMP was the principal constituent in toha extract, and inosine was the principal constituent in jeotsaeu extract. In conclusion, the content of major nitrogenous constituents in toha extract was more abundant than that in jeotsaeu extract. So toha was more excellent raw material than jeotsaeu.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1051-1057
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• 2000

Gamma irradiation was applied to develop fermented shrimp product with lower salt concentration, high sensory quality and storage stability. Shrimp was prepared with 15 and 20% of salt and fermented at $15^{\circ}C$. The sample was irradiated for 15% added salt at the 4th week and for 20% at the 6th week during fermentation with 0, 5 and 10 kGy absorbed doses. The irradiation was applied at optimum stage of fermentation determined when the content of amino nitrogen(AN) arrived approximately 400 mg%. Chemical properties such as amino nitrogen(AN), volatile base nitrogen(VBN), trimethylamine(TMA) and neutral protease activity were examined during whole fermentation. The AN, VBN, TMA and protease activity were not affected immediately after gamma irradiation. The more NaCl concentrations and irradiation dose, the less content of chemical compounds and protease activity was found. From the results of chemical properties, it was concluded that fermented shrimp with 15% of salt and irradiated at 10 kGy before optimum fermentation, or 20% and 5 kGy or above were maintained the sound quality during storage compared with the control.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.295-295
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• 2007