Theoretical study of the Alfven Eigenmode stability in CFETR steady state discharges

2021 ◽  
Author(s):  
Jacobo Varela Rodríguez ◽  
Juan Huang ◽  
Donald A Spong ◽  
Jiale Chen ◽  
Vincent Chan ◽  
...  
Keyword(s):  
Growth Rate ◽  
Steady State ◽  
Growth Rates ◽  
Alpha Particles ◽  
Larmor Radius ◽  
Plasma Region ◽  
Transport Barrier ◽  
Lower Growth ◽  
Stabilizing Effect ◽  
Damping Effects

Abstract The aim of this study is to analyze the stability of Alfven Eigenmodes (AE) in the China Fusion Engineering Test Reactor (CFETR) plasma for steady state operations. The analysis is done using the gyro-fluid code FAR3d including the effect of the acoustic modes, EP Finite Larmor radius damping effects and multiple energetic particle populations. Two high poloidal β scenarios are studied with respect to the location of the internal transport barrier (ITB) at r/a ≈ 0.45 (case A) and r/a ≈ 0.6 (case B). Both operation scenarios show a narrow TAE gap between the inner-middle plasma region and a wide EAE gap all along the plasma radius. The AE stability of CFETR plasmas improves if the ITB is located inwards, case A, showing AEs with lower growth rates with respect to the case B. The AEs growth rate is smaller in the case A because the modes are located in the inner-middle plasma region where the stabilizing effect of the magnetic shear is stronger with respect to the case B. Multiple EP populations effects (NBI driven EP + alpha articles) are negligible for the case A, although the simulations for the case B show a stabilizing effect of the NBI EP on the n=1 BAE caused by alpha particles during the thermalization process. If the FLR damping effects are included in the simulations, the growth rate of the EAE/NAE decreases up to 70 %, particularly for n > 3 toroidal families. Low n AEs (n<6) show the largest growth rates. On the other hand, high n modes (n=6 to 15) are triggered in the frequency range of the NAE, strongly damped by the FLR effects.

scholarly journals Synthesis and Fermentation Properties of Novel Galacto-Oligosaccharides by β-Galactosidases fromBifidobacterium Species

2001 ◽  
Vol 67 (6) ◽  
pp. 2526-2530 ◽  
Author(s):  
Bodun A. Rabiu ◽  
Andrew J. Jay ◽  
Glenn R. Gibson ◽  
Robert A. Rastall
Keyword(s):  
Growth Rate ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Growth Rates ◽  
Transfer Reactions ◽  
Methylation Analysis ◽  
Lower Growth ◽  
Lactose Concentration ◽  
Pure Cultures ◽  
Layer Chromatography

ABSTRACT β-Galactosidase enzymes were extracted from pure cultures ofBifidobacterium angulatum, B. bifidum BB-12, B. adolescentis ANB-7, B. infantis DSM-20088, andB. pseudolongum DSM-20099 and used in glycosyl transfer reactions to synthesize oligosaccharides from lactose. At a lactose concentration of 30% (wt/wt) oligosaccharide yields of 24.7 to 47.6% occurred within 7 h. Examination of the products by thin-layer chromatography and methylation analysis revealed distinct product derived spectra from each enzyme. These were found to be different to that of Oligomate 55, a commercial prebiotic galacto-oligosaccharide. Fermentation testing of the oligosaccharides showed an increase in growth rate, compared to Oligomate 55, with products derived fromB. angulatum, B. bifidum, B. infantis, and B. pseudolongum. However B. adolescentis had a lower growth rates on its oligosaccharide compared with Oligomate 55. Mixed culture testing of the B. bifidum BS-4 oligosaccharide showed that the overall prebiotic effect was equivalent to that of Oligomate 55.

Resistive instability in a uniformly rotating magnetoplasma

1971 ◽  
Vol 6 (1) ◽  
pp. 73-85
Author(s):  
A. D. Lunn
Keyword(s):  
Magnetic Field ◽  
Growth Rates ◽  
Larmor Radius ◽  
Closed Set ◽  
Finite Larmor Radius ◽  
Integral Methods ◽  
Stabilizing Effect ◽  
Instability Growth ◽  
Linear Differential ◽  
The Stability

A closed set of guiding centre equations, derived for a rotating plasma in a static magnetic field, is applied to the problem of the stability of a plasma in a sheared field. The rotation is found to have a stabilizing effect in the absence of resistivity.A pair of coupled, linear differential equations is derived for the rotating plasma in a weakly sheared field. Dispersion relations are obtained by phase integral methods and, in the absence of finite Larmor radius effects and rotation, instability growth rates proportional to η½13 are found which become proportional to when either is included. The inclusion of both finite Larmor radius and rotation gives growing instabilities proportional to η which are stabilized by the rotation when the finite Larmor radius terms predominate.

A comparison of sires of Suffolk and Dutch Texel breeds and ewes of Greyface, Suffolk Cheviot and Dutch Texel breeds in terms of food intake, prolificacy and lamb growth rates

1999 ◽  
Vol 68 (4) ◽  
pp. 567-575 ◽  
Author(s):  
S. D. Johnston ◽  
R. W. J. Steen ◽  
D. J. Kilpatrick ◽  
D. E. Lowe ◽  
D. M. B. Chestnutt
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Growth Rates ◽  
Dry Matter ◽  
Lower Number ◽  
The Other ◽  
Lower Growth ◽  
Lamb Growth

AbstractA comparison was made over 2 years of sires of Suffolk and Dutch Texel breeds and ewes of Greyface (Border Leicester × Scottish Blackface), Suffolk Cheviot and Dutch Texel breeds in terms of food intake, prolificacy and lamb growth rates under a grass-based system of production. Suffolk Cheviot ewes consumed significantly more silage dry matter than the Greyface ewes in both years of the study. There was no overall difference between Greyface and Suffolk Cheviot ewes in terms of prolificacy. However lambs from Suffolk Cheviot ewes had a higher growth rate than lambs from Greyface ewes from birth to weaning in year 1 (P < 0·01). In the comparison of the three ewe breeds sired by Dutch Texel rams in year 2, Dutch Texel ewes produced a similar number of lambs to the other genotypes but had a higher incidence of difficult lambings, higher lamb mortality and consequently a lower number of lambs weaned. Purebred Dutch Texel male lambs had lower growth rates than crossbred Dutch Texel lambs (143 compared with 158 glday for lambs from Greyface ewes and 166 (s.e. 13.4) glday for lambs from Suffolk Cheviot ewes in year 1 and 183 compared with 251 and 248 respectively (s.e. 10.9) glday in year 2). Lambs sired by Suffolk rams had higher growth rates than those sired by Dutch Texel rams (252 compared with 224 (s.e. 5.4) glday) in year 2.

scholarly journals Growth Rate-Dependent Control in Enterococcus faecalis: Effects on the Transcriptome and Proteome, and Strong Regulation of Lactate Dehydrogenase

2011 ◽  
Vol 78 (1) ◽  
pp. 170-176 ◽  
Author(s):  
Ibrahim Mehmeti ◽  
Ellen M. Faergestad ◽  
Martijn Bekker ◽  
Lars Snipen ◽  
Ingolf F. Nes ◽  
...  
Keyword(s):  
Growth Rate ◽  
Lactate Dehydrogenase ◽  
Enterococcus Faecalis ◽  
Growth Rates ◽  
Posttranscriptional Regulation ◽  
High Growth ◽  
Regulation Of Expression ◽  
Lower Growth ◽  
Content Type ◽  
Rate Dependent

ABSTRACTEnterococcus faecalisV583 was grown in a glucose-limited chemostat at three different growth rates (0.05, 0.15, and 0.4 h−1). The fermentation pattern changed with growth rate, from a mostly homolactic profile at a high growth rate to a fermentation dominated by formate, acetate, and ethanol production at a low growth rate. A number of amino acids were consumed at the lower growth rates but not by fast-growing cells. The change in metabolic profile was caused mainly by decreased flux through lactate dehydrogenase. The transcription ofldh-1, encoding the principal lactate dehydrogenase, showed very strong growth rate dependence and differed by three orders of magnitude between the highest and the lowest growth rates. Despite the increase inldh-1 transcript, the content of the Ldh-1 protein was the same under all conditions. Using microarrays and quantitative PCR, the levels of 227 gene transcripts were found to be affected by the growth rate, and 56 differentially expressed proteins were found by proteomic analyses. Few genes or proteins showed a growth rate-dependent increase or decrease in expression across the whole range of conditions, and many showed a maximum or minimum at the middle growth rate (i.e., 0.15 h−1). For many gene products, a discrepancy between transcriptomic and proteomic data were seen, indicating posttranscriptional regulation of expression.

scholarly journals Stabilizing effect of optimally amplified streaks in parallel wakes

2013 ◽  
Vol 739 ◽  
pp. 37-56 ◽  
Author(s):  
Gerardo Del Guercio ◽  
Carlo Cossu ◽  
Gregory Pujals
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Initial Conditions ◽  
Initial Perturbation ◽  
Three Dimensional ◽  
Maximum Amplitude ◽  
Maximum Growth ◽  
Absolute Instability ◽  
Stabilizing Effect ◽  
The Absolute

AbstractWe show that optimal perturbations artificially forced in parallel wakes can be used to completely suppress the absolute instability and to reduce the maximum temporal growth rate of the inflectional instability. To this end we compute optimal transient energy growths of stable streamwise uniform perturbations supported by a parallel wake for a set of Reynolds numbers and spanwise wavenumbers. The maximum growth rates are shown to be proportional to the square of the Reynolds number and to increase with spanwise wavelengths with sinuous perturbations slightly more amplified than varicose ones. Optimal initial conditions consist of streamwise vortices and the optimally amplified perturbations are streamwise streaks. Families of nonlinear streaky wakes are then computed by direct numerical simulation using optimal initial vortices of increasing amplitude as initial conditions. The stabilizing effect of nonlinear streaks on temporal and spatiotemporal growth rates is then determined by analysing the linear impulse response supported by the maximum amplitude streaky wakes profiles. This analysis reveals that at $\mathit{Re}= 50$, streaks of spanwise amplitude ${A}_{s} \approx 8\hspace{0.167em} \% {U}_{\infty } $ can completely suppress the absolute instability, converting it into a convective instability. The sensitivity of the absolute and maximum temporal growth rates to streak amplitudes is found to be quadratic, as has been recently predicted. As the sensitivity to two-dimensional (2D, spanwise uniform) perturbations is linear, three-dimensional (3D) perturbations become more effective than the 2D ones only at finite amplitudes. Concerning the investigated cases, 3D perturbations become more effective than the 2D ones for streak amplitudes ${A}_{s} \gtrsim 3\hspace{0.167em} \% {U}_{\infty } $ in reducing the maximum temporal amplification and ${A}_{s} \gtrsim 12\hspace{0.167em} \% {U}_{\infty } $ in reducing the absolute growth rate. However, due to the large optimal energy growths they experience, 3D optimal perturbations are found to be much more efficient than 2D perturbations in terms of initial perturbation amplitudes. Despite their lower maximum transient amplification, varicose streaks are found to be always more effective than sinuous ones in stabilizing the wakes, in accordance with previous findings.

scholarly journals Growth in demand and supply of pulses in India-A normative approach

2016 ◽  
Vol 8 (4) ◽  
pp. 1756-1761
Author(s):  
P. D. Shivagangavva ◽  
B. S. Reddy
Keyword(s):  
Growth Rate ◽  
Significant Influence ◽  
Growth Rates ◽  
Narrow Gap ◽  
Lower Growth ◽  
Demand And Supply ◽  
Significant Growth ◽  
Normative Approach ◽  
Positive Growth ◽  
Positive Growth Rate

The changing scenario of consumption and production of pulses will have significant influence on the demand- supply prospects of pulses in India. The country as whole, production of redgram had increased marginally (0.45%) during 1980-2012(Overall study period), though there is positive and significant growth in production(2.86%) during 1980-90 (Period-I), mainly due to lower growth during 1991-2012(period-II). The significant growth in production (1.39%) and productivity (1.04%) of bengalgram in the entire period except area (0.35%) was observed. However, growth in greengram production (1.14%) and productivity (1.21%) was found almost similar. In case of blackgram, positive growth rate in area, productivity and production in both the periods have ultimately resulted higher growth rates in the overall period. The growth in total pulses production indicated that growth in area (-0.10%) was negative while it was positive both in production (1.49%) and productivity (1.59%) during period-I. Similar pattern of growth was observed during period-II and in the overall study period. The estimated demand for pulses were 183.62 lakh tonnes over supply of 148.66 lakh tonnes indicating deficit of 34.96 lakh tonnes during 2001 –2011. Further, demand for pulses expected to reach 225.36 and 255.16 lakh tonnes in the year 2020 and 2030 respectively. Whereas, supply of pulses will reach 218.50 and 237.00 lakh tonnes in the same period indicating narrow gap between demand and supply in the future.

scholarly journals Parasite co-infections show synergistic and antagonistic interactions on growth performance of East African zebu cattle under one year

Parasitology ◽  
2013 ◽  
Vol 140 (14) ◽  
pp. 1789-1798 ◽  
Author(s):  
S. M. THUMBI ◽  
B. M. de. C. BRONSVOORT ◽  
E. J. POOLE ◽  
H. KIARA ◽  
P. TOYE ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Daily Weight Gain ◽  
First Year ◽  
Zebu Cattle ◽  
Helminth Parasites ◽  
Lower Growth ◽  
One Year ◽  
First Year Of Life ◽  
Antagonistic Interactions

SUMMARYThe co-occurrence of different pathogen species and their simultaneous infection of hosts are common, and may affect host health outcomes. Co-infecting pathogens may interact synergistically (harming the host more) or antagonistically (harming the host less) compared with single infections. Here we have tested associations of infections and their co-infections with variation in growth rate using a subset of 455 animals of the Infectious Diseases of East Africa Livestock (IDEAL) cohort study surviving to one year. Data on live body weight, infections with helminth parasites and haemoparasites were collected every 5 weeks during the first year of life. Growth of zebu cattle during the first year of life was best described by a linear growth function. A large variation in daily weight gain with a range of 0·03–0·34 kg, and a mean of 0·135 kg (0·124, 0·146; 95% CI) was observed. After controlling for other significant covariates in mixed effects statistical models, the results revealed synergistic interactions (lower growth rates) with Theileria parva and Anaplasma marginale co-infections, and antagonistic interactions (relatively higher growth rates) with T. parva and Theileria mutans co-infections, compared with infections with T. parva only. Additionally, helminth infections can have a strong negative effect on the growth rates but this is burden-dependent, accounting for up to 30% decrease in growth rate in heavily infected animals. These findings present evidence of pathogen–pathogen interactions affecting host growth, and we discuss possible mechanisms that may explain observed directions of interactions as well as possible modifications to disease control strategies when co-infections are present.

The responses of photosynthesis and translocation rates to changes in the ζ ratio of light

1982 ◽  
Vol 60 (8) ◽  
pp. 1285-1291 ◽  
Author(s):  
John Hoddinott ◽  
Linda M. Hall
Keyword(s):  
Growth Rate ◽  
Steady State ◽  
Growth Rates ◽  
Light Quality ◽  
Wide Spectrum ◽  
Red Light ◽  
Sink Strength ◽  
Quality Change ◽  
Sun And Shade ◽  
Changing Light

The influence of wide spectrum illumination conditions, with red and far-red light mixed to simulate sun and shade conditions, upon rates of photosynthesis and translocation was observed. A steady-state 14CO2 labeling apparatus was used to measure the two processes simultaneously during a light quality change. Sun conditions supported lower rates of photosynthesis and translocation to illuminated sink leaves than shade conditions, but the rate of translocation was lower than expected on the basis of the decline in photosynthesis. Translocation rates to darkened sinks remained constant as the photosynthetic rates were altered by changing light quality. Sink leaflet growth rates were lower in sun than shade light. We conclude that this decline in growth rate, which is also a decline in sink strength, results in light quality exerting a smaller effect on translocation than on photosynthesis.

Analyzing growth in cell cultures. II. Effect of initial cell mass on growth

1986 ◽  
Vol 64 (1) ◽  
pp. 238-241 ◽  
Author(s):  
Susan R. Singer ◽  
Carl N. McDaniel
Keyword(s):  
Growth Rate ◽  
Cell Line ◽  
Cell Lines ◽  
Growth Rates ◽  
Relative Rate ◽  
Cell Mass ◽  
Mass Effect ◽  
Initial Mass ◽  
Lower Growth ◽  
Initial Cell

Numerous factors must be considered when analyzing growth in a cultured cell system. One extremely critical factor is the initial cell mass. The effect of initial mass (10 to 400 mg) on growth rate was assessed for cell lines tolerant and susceptible to the herbicides 3-amino-1,2,4-triazole (amitrole) and N-(phosphonomethyl)glycine (glyphosate). For a given cell line, the relationship between initial mass and growth rate was comparable in the presence and absence of the growth inhibitors. However, among cell lines the response varied. For one amitrole- and glyphosate-tolerant cell line, increased initial callus mass resulted in an increased relative rate of growth. However, the opposite effect was observed for another cell line which was also tolerant to both herbicides. For a third cell line which was herbicide sensitive no initial mass effect was observed. A fourth cell line (amitrole tolerant – glyphosate sensitive) also showed no initial mass effect except for the very small 10-mg calluses, which had significantly lower growth rates. The observed effect of initial mass was dependent on the method of calculating growth rates.

In-Situ Measurements of Stress during Electrodeposition of Copper Nanofilms: Surface and Grain-Boundary Migration of Atoms and the Effect of Chloride Ions

2018 ◽  
Vol MA2018-01 (32) ◽  
pp. 1980-1980
Author(s):  
Joe A. Murphy ◽  
Catherine Lenihan ◽  
Maria Rybalchenko ◽  
Nathan Quill ◽  
Robert P. Lynch ◽  
...  
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Steady State ◽  
Tensile Stress ◽  
Growth Rates ◽  
Ex Situ ◽  
Stress Measurements ◽  
Afm Imaging ◽  
State Stress

Electrodeposited metal films are often in a state of stress and this has been the subject of extensive experimental investigation and theoretical analysis1-4. We have been measuring stress development in situ during electrodeposition and correlating the results with in-situ AFM imaging during electrodeposition under similar conditions. In this paper we present results on the early stages of copper deposition from acidic CuSO4 electrolytes with and without chloride as an additive. To examine the effect of growth rate, sequential galvanostatic depositions were carried out (after an initial potentiostatic deposition of a thin layer of copper) over a relatively large range of growth rates (from 0.22 nm s-1 to 6.9 nm s-1) in additive-free electrolyte. At low growth rates, steady state stress was compressive. As growth rate was increased, the stress became less compressive and eventually became tensile. Crossover from compressive to tensile stress occurred at a growth rate of ~1 nm s-1. Both in-situ AFM imaging during deposition and ex-situ SEM imaging were used to characterise the evolution of grain size during the sequence of galvanostatic depositions used in the stress measurements. In general, grain size increased with continued deposition but eventually reached a constant value. Simulations based on Chason’s kinetic model3 gave a good fit of our experimental stress measurements in the region of constant grain size (~970 nm). The parameters from this fit were then used to model the steady state stress as a function growth rate and grain size. The values predicted by the model are plotted against the values from the experimental measurements in Figure 1. It can be seen that there is good agreement between model and experiment. The effect of added chloride in the electrolyte was also investigated. Even at low concentrations (< 1 ppm), the presence of chloride considerably reduced the tensile stress. Chloride-free and chloride-containing electrolytes also showed very different behaviours after interruption of electrodeposition. In chloride-free electrolyte, the tensile steady-state stress observed during deposition changed to compressive stress on interruption of the deposition. However, in chloride-containing electrolyte, the stress became even more tensile on interruption of deposition. Our experimental results on the change from one type of behaviour to the other as the chloride concentration was increased will be described and possible mechanisms will be discussed. References O.E. Kongstein, U. Bertoci and G.R. Stafford, J. Electrochem. Soc. 152, C116 (2005). S. Ahmed, T.T. Ahmed, M. O'Grady, S. Nakahara and D.N. Buckley, J. Applied Physics 103, (2008). E. Chason, Thin Solid Films 526, 1 (2012). E. Chason, A. Engwall, F. Pei, M. Lafouresse, U. Bertocci, G. Stafford, J.A. Murphy, C. Lenihan and D.N. Buckley, J. Electrochem. Soc. 160, D3285 (2013) Figure 1

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