Melting and zero growth rate temperatures of syndiotactic polystryrene

2008 ◽  
Vol 286 (8-9) ◽  
pp. 983-991 ◽  
Author(s):  
A. Sorrentino ◽  
R. Pantani ◽  
G. Titomanlio
Keyword(s):  
Growth Rate ◽  
Zero Growth

Effect of a Finite Boundary Junction Mobility on the Growth Rate of Two and Three Dimensional Grains

2012 ◽  
Vol 715-716 ◽  
pp. 574-578 ◽  
Author(s):  
Luis A. Barrales Mora
Keyword(s):  
Growth Rate ◽  
Three Dimensional ◽  
Granular System ◽  
Present Contribution ◽  
Von Neumann ◽  
Model Simulations ◽  
Theoretical Approaches ◽  
Dimensional Network ◽  
Zero Growth ◽  
Good Agreement

t has been shown by computer simulations that the MacPherson-Srolovitz relation predicts accurately the growth rate of a grain undergoing ideal grain growth. However, since a finite mobility of the boundary junctions (triple lines and quadruple junctions) affects the evolution of a granular system, it is necessary to modify this equation in order to take into account their effect. In the present contribution, an equation which allows considering these factors is presented and used to modify the von Neumann-Mullins and MacPherson-Srolovitz equations. In order to corroborate these equations two and three dimensional network model simulations were performed. The results showed a very good agreement with the theoretical approaches for both dimensions and all topological classes except those near the classes of zero growth rate in 3D. The reason is that the proposed function is very sensitive to small changes of the finite mobility of the junctions.

On the decay of a dipole pump wave to half-harmonics

1991 ◽  
Vol 46 (2) ◽  
pp. 231-236 ◽  
Author(s):  
J. A. Heikkinen ◽  
T. J. H. Pättikangas ◽  
G. Devillers
Keyword(s):  
Growth Rate ◽  
Pump Wave ◽  
Wave Interaction ◽  
Interaction Coefficient ◽  
Slow Waves ◽  
Magnetosonic Wave ◽  
Decay Modes ◽  
Parametric Decay ◽  
Zero Growth ◽  
Vlasov Plasma

Starting from a three-wave interaction coefficient for a homogeneous Vlasov plasma, we show that the parametric decay to half-harmonics has zero growth rate if the wavenumber of the pump wave vanishes. Earlier proofs of this fact for electrostatic decay modes are thus extended for a general case. As a specific example, we study the decay of a fast magnetosonic wave to two slow waves.

Island Dynamics in Film Aging

1990 ◽  
Vol 202 ◽  
Author(s):  
S. P. Marsh ◽  
M. E. Glicksman
Keyword(s):  
Growth Rate ◽  
Domain Size ◽  
Cube Root ◽  
Global Constraint ◽  
Concentration Gradients ◽  
Average Growth ◽  
Zero Growth ◽  
Self Similar ◽  
The Individual ◽  
Island Dynamics

ABSTRACTA theory is presented which describes the capillary-driven aging of discontinuous thin films on a substrate, where the primary transport mechanism among the domains is two-dimensional diffusion of species over the substrate. This theory employs a statistical dynamics formulation, whereby the average growth rate for each domain size class is determined relative to the critical (zero-growth) domain size. The time dependence of the critical size is determined through a global constraint on the individual fields. The effect of fractional area coverage, Aa, is accounted for through a second global constraint over the distribution of island sizes.This theory yields a self-similar size distribution that is fairly insensitive to Aa. The critical island radius, R*, is found to increase asymptotically as the cube-root of time. The growth rate of R* increases with Aa, which results from the closer proximity of the islands and steeper concentration gradients as Aa increases.

Stability classification of a Ricker model with two random parameters

2002 ◽  
Vol 34 (1) ◽  
pp. 112-127 ◽  
Author(s):  
Henrik Fagerholm ◽  
Göran Högnäs
Keyword(s):  
Growth Rate ◽  
Isolated Population ◽  
Random Parameters ◽  
Stochastic Version ◽  
Ricker Model ◽  
Zero Growth ◽  
Null Recurrence ◽  
Per Capita ◽  
Stability Classification

We consider a stochastic version of the Ricker model describing the density of an unstructured isolated population. In particular, we investigate the effects of independently varying the per capita growth rate and the parameter governing density dependent feedback. We derive conditions on the distributions sufficient to guarantee different forms of stochastic stability such as null recurrence or positive recurrence. We find, for example, that null recurrence appears in two widely different scenarios: when there is a mean-zero growth rate or via a growth-catastrophe behaviour.

Economic Challenges Facing the Philippines

1983 ◽  
Vol 14 (2) ◽  
pp. 254-261 ◽  
Author(s):  
Frank H. Golay
Keyword(s):  
Growth Rate ◽  
The Philippines ◽  
Reproductive Age ◽  
Age Group ◽  
Economic Problems ◽  
Zero Growth ◽  
Over Exploitation ◽  
Land Frontier ◽  
Forestry Resources ◽  
Reproductive Age Group

The Philippine society confronts formidable longer-term economic problems. The exhaustion of the land frontier suitable for production of present crops under existing techniques, which is compounded by degradation of the environment by wasteful harvesting of forestry resources and over-exploitation of inshore fisheries is an obvious problem. A comparable problem arises in the inertia built into the age structure of the Philippine population. In 1970, those under 15 years of age accounted for 45.6 per cent of all Filipinos and estimated population growth in the 1970s was 2.7 per cent, a rate more than double the “zero-growth rate”. If the growth rate should fall to the “zero-growth rate” tomorrow, the Philippine population would continue to grow for the better part of a century and would virtually double as cohorts of Filipinos entering the reproductive age group would continue to increase for many years.

Fermentation kinetics ofZymomonas mobilisnear zero growth rate

1987 ◽  
Vol 29 (4) ◽  
pp. 502-512 ◽  
Author(s):  
I. M. L. Jöbses ◽  
H. C. H. Hiemstra ◽  
J. A. Roels
Keyword(s):  
Growth Rate ◽  
Fermentation Kinetics ◽  
Zero Growth

Toxicity Test of Chromium and Glutaraldehyde to Determine Greener Chemical in Tannery Industry

2017 ◽  
Vol 901 ◽  
pp. 160-165 ◽  
Author(s):  
Laili Rachmawati ◽  
Mustafidah Udkhiyati
Keyword(s):  
Growth Rate ◽  
Aspergillus Niger ◽  
High Growth ◽  
Potato Dextrose Agar ◽  
High Scale ◽  
Resistance Level ◽  
Tannery Industry ◽  
Zero Growth ◽  
Toxicity Level ◽  
One Way Anova

The aim of this study was to investigate the toxicity level of chromium and glutaraldehyde. This research was conducted by testing the resistance level of fungi (Aspergillus niger sp.) toward glutaraldehyde and chromium in the medium of Potato Dextrose Agar (PDA). Variable of this experiment was the growth of Aspergillus niger sp. that indicates the resistance level of Aspergillus niger sp. The growth rate of Aspergillus niger sp. was classified on four scales. They were, (I) scale 1: zero growth; (II) scale 2: low growth (+); (III) scale 3: medium growth (++); (IV) Scale: 4 high growth (+++). All collected data were analysed by One Way ANOVA. The result showed that the toxicity of chromium and glutaraldehyde tanning material were highly significantly different toward Aspergillus niger (P<0,01). The Aspergillus niger sp. growth rate scale in chromium medium was high (scale 4: 4.00±0.00). Meanwhile, the growth rate scale of the Aspergillus niger sp. in glutaraldehyde medium was low (scale 2: 1.33 ± 0.58). Based on the fungi growth rate, it can be concluded that glutaraldehyde was more toxic than chromium tanning material toward Aspergillus niger sp. Furthermore, it can be said that glutaraldehyde is not quite ideal to be used as an alternative of chromium as a tanning material.

scholarly journals Surveillance imaging for sporadic renal angiomyolipoma less than 40 mm: lessons learnt and recommendations from the experience of a large district general hospital

2018 ◽  
Vol 100 (6) ◽  
pp. 480-484 ◽  
Author(s):  
KE Chan ◽  
ECP Chedgy ◽  
CL Bent ◽  
KJ Turner
Keyword(s):  
Growth Rate ◽  
District General Hospital ◽  
Renal Angiomyolipoma ◽  
Surveillance Programme ◽  
Surveillance Imaging ◽  
Life Threatening ◽  
Surveillance Interval ◽  
Zero Growth ◽  
Spontaneous Haemorrhage

Introduction Sporadic renal angiomyolipomas, although benign in natural can cause life-threatening spontaneous haemorrhage. Surveillance of smaller lesions is recommended but there is no guidance on the surveillance interval or modality. Our aim was to study our sporadic angiomyolipoma population to determine the growth rate, factors that were associated with a higher growth rate and design a surveillance programme. Materials and methods All sporadic renal angiomyolipomas diagnosed between September 2009 and March 2015 were included. Patients with a diagnosis of tuberous sclerosis were excluded. Results A total of 217 sporadic renal angiomyolipomas were diagnosed. The median follow-up was 24 months (range 10–118 months). The median size at diagnosis was 9.00 mm with a mean growth rate of 0.13 mm/year (standard deviation 0.88). One hundred and fifty angiomyolipomas (69%) were shown to have negative or zero growth. In the remaining 67, 59 had a growth rate of less than 2.00 mm/year. Size of angiomyolipoma, tumour burden and age were not associated with a higher growth rate on multivariate analysis. Conclusion The majority of sporadic angiomyolipomas are small and do not grow. Our practice is to perform surveillance for those greater than 20 mm, with five-yearly ultrasound scans for 21–29 mm, and two-yearly surveillance for 30–39 mm tumours.

scholarly journals The changing age-structure of Coronavirus SARS-CoV-2 deaths and cases a case study of Paraná, Brazil

2020 ◽  
Author(s):  
Raquel Guimaraes ◽  
Marília Nepomuceno ◽  
Acácia Maria Lourenço Francisco Nasr ◽  
Garcia ◽  
Maria Goretti David Lopes ◽  
...  
Keyword(s):  
Growth Rate ◽  
State Government ◽  
Age Structure ◽  
The Elderly ◽  
Interesting Case ◽  
The State ◽  
Average Growth ◽  
Zero Growth ◽  
In The Beginning ◽  
Changes Over Time

The goal of this paper is to explore the demographic evolution of the Coronavirus SARS-CoV-2 deaths and cases in the state of Paraná, Brazil. We focus on changes in the age-pattern of cases and deaths attributed to the COVID-19. Paraná is an interesting case of study in Brazil due to several aspects. First, it is one of the most developed states of the country. Second, the population growth rate is rapidly approaching zero growth, with an observed average growth rate of 0.78 percent per year in the decade 2010/2020, and of 0.28 percent per year in the period 2030/2040. Third, Parana has an older population age-structure than that of the whole country. Finally, although the state government pushed for earlier Non-Pharmaceutical Interventions to control the pandemic, data shows that they only took effect in the very late stages. Taken together, we claim that these aspects created a very particular setting, in which changes over time in the age-structure of the deaths attributed to COVID-19 could be observed: in the beginning of the pandemic, the age-structure of the deaths was concentrated among the elderly. As the pandemic unfolds, deaths were spreading over younger ages. Finally, we speculate on mechanisms behind the changes in the age structure of the COVID-19 deaths in Paraná.

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