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31.
A new ultrasonic method — thermoacoustic analysis — is reported for the detection of the added chemical preservatives in branded milk. The nature of variation and shift in the thermal response of the acoustic parameters specific acoustic impedance, adiabatic compressibility and Rao’s specific sound velocity for different samples of branded milk as compared to the chemical added pure milk are explained as due to the presence of chemicals in these branded samples.  相似文献   
32.
Density functional and ab initio calculations at CBS-QB3 levels of theory were employed with a series of isodesmic reactions to determine the thermochemistry of the 2-oxopropyl or acetonyl radical (CH(3)COC*H2). In turn, this was used to determine formation enthalpies of 2-oxoethyl or formylmethyl (C*H(2)CHO), 2-oxobutyl (C*H(2)COC(2)H(5)), 1-methyl-2-oxopropyl or methylacetonyl (C*H(CH(3))COCH(3)), 1-methyl-2-oxobutyl (C*H(CH(3))COC(2)H(5)), and 3-oxopentyl (C*H(2)CH2COC(2)H(5)). Our computed standard enthalpy of formation of -34.9 +/- 1.9 kJ mol-1 and a resonance stabilization energy of approximately 22 kJ mol(-1) for acetonyl are in good agreement with recent re-determinations, which have indicated a substantial lowering in the long-established value for DeltaH(f)o (298.15 K). A bond dissociation energy of 401 kJ mol(-1) is suggested for the C-H bond in acetone with consistent values for the others. The calculations support the enthalpy of formation of acetaldehyde obtained from combustion experiments of -166.1 kJ mol(-1) rather than the figure of -170.7 kJ mol(-1) extracted from enthalpies of reduction and, in addition, serve to reduce the uncertainty in DeltaH(f)o the 2-oxoethyl radical to +13 +/- 2 kJ mol(-1).  相似文献   
33.

The aim of this research was to study the production of humic acids (HA) by Trichoderma reesei from empty fruit bunches (EFBs) of palm oil processing, with a focus on the effects of lignocellulosic content and residual lipids. EFBs from two different soils and palm oil producers were previously characterized about their lignocellulosic composition. Submerged fermentations were inoculated with T. reesei spores and set up with or without residual lipids. The results showed that the soil and the processing for removal of the palm fresh fruits were crucial to EFB quality. Thus, EFBs were classified as type 1 (higher lignocellulosic and fatty acids composition similar to the palm oil and palm kernel oil) and type 2 (lower lignocellulosic content and fatty acids composition similar to palm oil). Despite the different profiles, the fungal growth was similar for both EFB types. HA production was associated with fungal growth, and it was higher without lipids for both EFBs. The highest HA productivity was obtained from type 1 EFB (approximately 90 mg L−1 at 48 h). Therefore, the lignocellulosic composition and the nature of the residual lipids in EFBs play an important role in HA production by submerged fermentation.

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