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排序方式: 共有377条查询结果,搜索用时 290 毫秒
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2.
A. Moser B. Mayr W. Jury W. Steiner P. Horvat 《Bioprocess and biosystems engineering》1991,7(4):177-182
The macroscopic mathematical model based on compartments with ideal mixing zones and tanks-in series was evaluated. Based on the experimental data obtained in a 300 dm3 pilot reactor and the dependence of mixing time on the volume of liquid phase, we have found mathematical relations between the ratio of vessel diameter to liquid level, adjustable parameters of model and the mixing time.List of Symbols
V dm3
total volume of bioreactor
-
V
g dm3
total volume of liquid
-
V
1 dm3
volume of ideally mixed zone in the vessel
-
V
2 dm3
volume of macromixer in inner circulation flows
-
V
3 dm3
volume of liquid phase in the pump
-
V
4 dm3
volume of liquid phase in the pipe between the vessel and the pump
-
V
5 dm3
volume of liquid phase in the pipe between the pump and air input system included falling jet
-
V
LT dm3
volume of liquid in the tank
-
V
LC dm3
volume of liquid in the circulation system
-
F
E dm3/s
inner volumetric circulation flow rate across the macromixers
-
F
cir dm3/s
external volumetric circulation flow rate, pumping capacity
-
t
A s
time interval of the pulse application
-
t
AA s
time point of the pulse application related to the free choosen starting point of the experiment
-
t
m s
mixing time
-
t
c s
circulation time
-
t
end s
end time of simulation
-
C
*,* kg/m3
concentration of tracer in the indicated compartment
-
C
0 kg/m3
concentration of the tracer before the injection
-
C
t kg/m3
concentration of the tracer at the indicated time
-
C
kg/m3
theoretical concentration of the full mixed tracer
-
C
sim kg/m3
calculated concentration of tracer during numerical integration method
-
i
index of an arbitrary tank
-
D
T m
diameter of bioreactor
-
D 1/s
dilution rate
-
H
L m
level of liquid in the unaerated vessel
-
vector of inhomogenities 相似文献
3.
The Lactococcus lactis sex-factor aggregation gene cluA 总被引:4,自引:0,他引:4
Jean-Jacques Godon Karen Jury Claire A. Shearman Michael J. Gasson 《Molecular microbiology》1994,12(4):655-663
A gene, cluA, was cloned from the chromosomally located sex factor of Lactococcus lactis MG1363. Sequence analysis revealed significant homology with previously described aggregation proteins in Enterococcus and Streptococcus species. The possibility that cluA was an equivalent protein involved in cell aggregation between donor and recipient bacteria during lactococcal conjugation was confirmed by its expression under the control of a heterologous promoter in L. lactis. Analysis of the homology between the CluA protein and the related proteins of Enterococcus and Streptococcus allowed a common structure for these proteins to be postulated. This consisted of five domains. Functionally conserved domains I and V act respectively as a secretary leader and C-terminal membrane anchor. Domains II and IV are conserved at the amino acid level and probably have common structural roles whereas domain III is variable and may control binding specificity. 相似文献
4.
Size structure of the metazoan community in a Piedmont stream 总被引:1,自引:0,他引:1
N. LeRoy Poff Margaret A. Palmer Paul L. Angermeier Robert L. Vadas Jr. Christine C. Hakenkamp Alexa Bely Peter Arensburger Andrew P. Martin 《Oecologia》1993,95(2):202-209
We characterized the size structure of virtually the entire metazoan community in a fourth order, sandybottomed Piedmont stream during late summer. Our study, the first to sample across all habitat types and sizes of metazoans in an aquatic ecosystem, indicates that at the community level, stream size spectra may be bimodal for the benthos or trimodal when fish are included. Animals spanning 10 orders of magnitude in dry mass (from gastrotrichs to fish) were quantitatively collected from nine habitat types. The bimodal benthic size spectrum was characterized by a meiofaunal component (mostly oligochaetes and micro-crustacea) and a macrobenthic component (mostly the introduced asiatic clam, Corbicula fluminea). Insects contributed little to overall standing crop. Size-specific contribution to whole-community metabolism was assessed using allometric equations for respiration, and we found a distinctly bimodal distribution across the entire metazoan size range, with peaks in the meiofaunal and benthic macrofaunal size ranges. Our bimodal benthic size spectrum is similar to that observed for marine benthos but not to other freshwater benthic systems, possibly because the entire range of habitat types and/or animal sizes were not sampled in the latter. Numerous factors may influence size spectra in stream ecosystems, including local geomorphic (habitat) conditions, water level fluctuations, species introductions, and predation processes. 相似文献
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McLachlan Rowan H. Price James T. Muñoz-Garcia Agustí Weisleder Noah L. Jury Christopher P. Toonen Robert J. Grottoli Andréa G. 《Coral reefs (Online)》2021,40(5):1505-1523
Coral Reefs - To evaluate potential coral adaptive mechanisms, we investigated physiological traits (biomass, lipid, protein, chlorophyll, and isotopic proxies for trophic strategy) in eight... 相似文献
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10.
A. C. Povey F. Jury W. M. Dippnall A. E. Smith S. Thomson B. Mackness 《Biomarkers》2013,18(2):188-202
Previously we reported that in sheep dippers exposed to organophosphates the frequency of paraoxonase (PON1) polymorphisms differed between those with or without self-reported ill health. We have now examined whether polymorphisms in other genes involved in xenobiotic metabolism alter disease risk in this population. There were elevated but non-significant risks associated with the CYP2D6 WT genotype (odds ratio (OR) 1.47, 95% CI 0.83–2.60), or a GSTP1*B or *C allele (OR 1.37, 95% CI 0.88–2.01) or being GSTM1*2/GSTT1*2 homozygous (OR 1.61, 95% CI 0.74–3.48). Similar results were generally obtained after the exclusion of subjects to obtain a more homogenous case-referent population: for double null GSTM1 and GSTT1 homozygotes the OR was 2.06 (95% CI 0.85–2.04). In those also likely to have been exposed to diazinon, risks associated with a GSTP1*B or *C allele (OR 1.82, 95% CI 0.92–3.63) or a GSTM1*2/GSTT1*2 homozygous (OR 2.60, 95% CI 0.72–10.42) were elevated but not to a significant extent. Risk associated with PON1 genotype and phenotype varied with CYP2D6 and GSTP1 genotype but not consistently with a priori hypotheses. Further work is necessary to delineate more clearly pathways of organophosphate activation and non-PON1 pathways of detoxification and to confirm whether CYP and GST polymorphisms alter disease risk in populations exposed to organophosphates. 相似文献