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List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
Dimethylamine is a colorless flammable gas at room temperature. It has a pungent, fishy, or ammonia-like odor at room temperature and is shipped and marketed in compressed liquid form. The air odor threshold concentration for dimethylamine is 0.34 ppm of air. It is very soluble in water, and soluble in alcohol and ether. It is incompatible with oxidizing materials, acrylaldehyde, fluorine, maleic anhydride, chlorine, or mercury. Dimethylamine is a precursor to several industrially important compounds. For instance, it is used in the manufacture of several products, e.g., for the vulcanization process of rubber, as detergent soaps, in leather tanning, in the manufacture of pharmaceuticals, and also for cellulose acetate rayon treatment.
An indicator for sulfuric acid–amine nucleation in atmospheric environments
Published in Aerosol Science and Technology, 2021
Runlong Cai, Chao Yan, Douglas R. Worsnop, Federico Bianchi, Veli-Matti Kerminen, Yongchun Liu, Lin Wang, Jun Zheng, Markku Kulmala, Jingkun Jiang
The formula for I is derived according to the kinetics of H2SO4–base cluster formation. Figure 2 shows a simplified schematic diagram of neutral H2SO4–base nucleation. A represents the acid (H2SO4), B represents the base, particles indicate the condensation or coagulation sink, and γ is the evaporation rate of the A1B1 cluster, that is, a cluster composed of one H2SO4 molecule and one base molecule. For the convenience of illustration, we first take the base as dimethylamine (DMA) and then discuss the possibility to generalize it to other amines, ammonia, and organics. The details of relevant models were elaborated previously (Cai et al. 2021; Chen et al. 2012; Jen, McMurry, and Hanson 2014). There are also models including unstable clusters and the ion-induced mechanism for H2SO4–amine/ammonia nucleation (McGrath et al. 2012; Myllys et al. 2019b; Yu et al. 2018; Yu et al. 2020). Besides, the mechanism for H2SO4–base nucleation may vary with the base. However, I is derived based on the simplified model illustrated in Figure 2 because it is proposed to indicate the occurrence of an NPF event rather than to simulate the formation rate.
Microbial properties of the granular sludge in a psychrophilic UASB reactor fed with electronics industry wastewater containing organic chemicals
Published in Journal of Environmental Science and Health, Part A, 2021
Kazuaki Syutsubo, Tsuyoshi Danshita, Haruhiko Sumino, Akinori Iguchi, Yasuyuki Takemura
As shown in Figure 2(C), TMAH was converted to CH4 without the accumulation of intermediates, such as methanol, until the ending phase of the batch experiment (10 hours later). However, degradation and methanation of TMAH were clearly inhibited by the presence of CHCl3 (Figure 2(D)). These observations indicated that TMAH was converted directly to methane by methanogenic archaea. In this study, trimethylamine, dimethylamine and monomethylamine were not detected as intermediates. Furthermore, for the TMAH-acclimated sludge, it has been confirmed that the MPA for monomethylamine and methanol is apparently lower than that for TMAH.[9] Degradation of TMAH is known to be associated with demethylation and formaldehyde formation under aerobic conditions.[18] The TMAH degradation pathway in the previous study is quite different to the direct methanation of TMAH by methanogens (archaea) suggested in the present study. Also, it is possible that TMAH has a negative effect on anaerobic granular sludge formation owing to the simplification of microbial diversity (i.e., degradation pathway).
Effects of Ozonated Water Treatment on Physico-chemical, Microbiological and Sensory Characteristics Changes of Nile Tilapia (Oreochromis niloticus) Fillets during Storage in Ice
Published in Ozone: Science & Engineering, 2020
Yongqiang Zhao, Shaoling Yang, Xianqing Yang, Laihao Li, Shuxian Hao, Jianwei Cen, Ya Wei, Chunsheng Li, Hongjie Zhang
TVB-N content has been traditionally used as an indicator of quality in fish products because it exhibits a close relationship with the sensory score (Ocaño-Higuera et al. 2011). The TVB-N (including trimethylamine, dimethylamine, ammonia and other compounds associated with aquatic-product spoilage) concentrations of the two groups during 18-day storage in ice are shown in Figure 2b. At the beginning of storage, the TVB-N values of treated and control group fillets were 12.38 ± 1.13 mg/100 g (of muscle) and 14.35 ± 0.84 mg/100 g, respectively. During the entire period of storage, the TVB-N values in both groups increased with time, which was primarily due to the activity of proteolytic microorganisms decomposing the fish flesh, concomitant with a pH increase (Figure 2a) (Ocaño-Higuera et al. 2011). Similar results have been observed for whole ungutted, whole gutted and filleted tilapia during refrigerated storage (Rong et al. 2009).