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61.
Noori M. Cata Saady Subba Rao Chaganti Jerald A. Lalman Sathyanarayanan S. Veeravalli Saravanan R. Shanmugam Daniel D. Heath 《International Journal of Hydrogen Energy》2012
The effects of lauric (LUA), myristic (MA), palmitic (PA), and a mixture of myristic:palmitic (MA:PA) acids on hydrogen (H2) production from glucose degradation using anaerobic mixed cultures were assessed at 37 °C with an initial pH set at 5.0 and 7.131 mM of each acid. The maximum H2 yield (2.53 ± 0.18 mol mol−1 glucose) was observed in cultures treated with PA. A principal component analysis (PCA) of the by-products and the microbial population data sets detected similarities between the controls and PA treated cultures; however, differences were observed between the controls and PA treated cultures in comparison to the MA and LUA treated cultures. The flux balance analysis (FBA) showed that PA decreased the quantity of H2 consumed via homoacetogenesis compared to the other LCFAs. The control culture was dominated by Thermoanaerovibrio acidaminovorans (60%), Geobacillus sp. and Eubacterium sp. (28%), while Clostridium sp. was less than 1%. Treatment with PA, MA, MA:PA, or LUA increased the H2 producers (Clostridium sp. and Bacillus sp.) population by approximately 48, 67, 86, and 86%, respectively. 相似文献
62.
Noori M. Cata Saady Subba Rao Chaganti Jerald A. Lalman Daniel Heath 《International Journal of Hydrogen Energy》2012
Genomic and statistical methods were used to demonstrate the effects of linoleic acid (LA) on hydrogen (H2) production in mixed anaerobic cultures from two sources (designated as A and B). The microbial composition of the control cultures CA and CB were statistically different. Bacteroidaceae (26%) and Clostridiaceae (10%) dominated CA whereas Clostridiaceae (33%) and Bacteroidaceae (10%) dominated CB. Homoacetogens directed 42% of the electron equivalents to acetate production and decreased the H2 yield by 50% in CA compared to CB. The maximum H2 yields (3.11 ± 0.02 and 3.11 ± 0.07 mol H2 mol−1 glucose in LA-treated cultures ALA and BLA, respectively) were statistically the same. Cultures ALA and BLA followed the acetate-butyrate pathway while CA and CB followed propionate and homoacetogenic pathways. LA-treated and control cultures were statistically different based on the type and quantity of metabolites; the differences were also confirmed by principal component analysis (PCA). 相似文献
63.
Heath H. Himstedt Mark S. Huberty Alon V. McCormick Lanny D. Schmidt E. L. Cussler 《American Institute of Chemical Engineers》2015,61(4):1364-1371
Conversion to ammonia with Haber–Bosch catalysts can be increased above 95% by selective absorption of ammonia by MgCl2. The maximum conversion depends on reaction and absorption equilibria. At very short times, the measured conversion rate is the same with and without absorption by the MgCl2 salt; the overall rate constants are comparable to those in the literature. At larger times, conversion to ammonia can be over seven times greater with MgCl2 than without. However, the overall rate constants can be over 10 times slower because they are controlled by ammonia diffusion in the solid salt. An approximate, pseudosteady state theory consistent with these results provides a strategy for improving the overall rate while keeping the conversion over 90%. For example, the absorption rates might be increased using smaller particles of absorbent on a porous inert absorbent support. The results provide part of the basis for designing small scale ammonia plants. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1364–1371, 2015 相似文献
64.
2D Materials: The Influence of Water on the Optical Properties of Single‐Layer Molybdenum Disulfide (Adv. Mater. 17/2015)
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This article explores the historical context, process and result of introducing and implementing ‘new’ town planning in early post‐war Taiwan. The two so‐called ‘garden cities’ are examined: Jhong‐Sing New Village and Yonghe City, both of which were formulated in the mid‐1950s by the same group of local planners. It reveals that the assumed necessity of importing Western planning paradigms arose from the abrupt escalation of urban concentration caused by the late 1940s mass migrations from China. To cope with this unprecedented population growth, planning profession was swiftly established. The novice planners, in search of a reference for developing ‘new’ towns to decentralise excessive urbanisation, modelled their ‘new’ town planning on English suburban morphology. In the absence of an input of external expertise, the planners appeared to mistake aesthetic order and pastoral imagery of low‐density residential development in England as practically viable solutions to the pressing urban problems in Taiwan. In a false hope that adopting Western ideas and practices would quickly lead the island to a better world, Taiwan initiated the importation of planning paradigms. This planning transfer not only evidently manifests a mode of ‘borrowing’ in post‐colonial countries in international diffusion but also re‐articulates the disseminating nature of modern planning and the existence of one‐direction flows characterising the global dynamics of diffusion in the twentieth century. 相似文献
68.
Dr. Rachel S. Heath Jack J. Sangster Prof. Nicholas J. Turner 《Chembiochem : a European journal of chemical biology》2022,23(7):e202200075
The enantioselective oxidation of 2° alcohols to ketones is an important reaction in synthetic chemistry, especially if it can be achieved using O2-driven alcohol oxidases under mild reaction conditions. However to date, oxidation of secondary alcohols using alcohol oxidases has focused on activated benzylic or allylic substrates, with unactivated secondary alcohols showing poor activity. Here we show that cholesterol oxidase (EC 1.1.3.6) could be engineered for activity towards a range of aliphatic, cyclic, acyclic, allylic and benzylic secondary alcohols. Additionally, since the variants demonstrated high (S)-selectivity, deracemisation reactions were performed in the presence of ammonia borane to obtain enantiopure (R)-alcohols. 相似文献
69.
The permeability of native and commercial grades of gutta-percha (trans-polyisoprene), was determined and related to diffusion rate both below and above the glass transition temperature (Tg) and the melting point (Tm). Both radially drawn and undrawn membranes were evaluated. Five gases (O2, N2, CO2, H2 and He) were used as permeants and the measurements were taken both above and below the polymers' crystalline Tm. The diffusivity of the gases was found to have an increased rate above the Tm. The reduction of solubility, diffusivity and permeability with increasing draw ratio was attributed to an increase in crystallinity. 相似文献
70.
The multi-scale Gibbs–Helmholtz constrained (GHC) equation is a new predictive cubic equation of state that constrains the energy parameter in the SRK equation to satisfy the Gibbs–Helmholtz equation. It makes use of internal energies of departure calculated from NTP Monte Carlo simulations at the molecular length scale and a novel up-scaling expression to determine the energy parameter at the bulk phase length scale. 相似文献