scholarly journals Ostwald Growth Rate in Controlled Covid-19 Epidemic Spreading as in Arrested Growth in Quantum Complex Matter

2020 ◽  
Vol 5 (2) ◽  
pp. 23 ◽  
Author(s):  
Antonio Bianconi ◽  
Augusto Marcelli ◽  
Gaetano Campi ◽  
Andrea Perali
Keyword(s):  
Growth Rate ◽  
Metastable Phase ◽  
Quantitative Measure ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Oxygen Interstitial ◽  
S Factor ◽  
Successful Approach ◽  
Containment Policy ◽  
Complex Matter

Here, we focus on the data analysis of the growth of epidemic spread of Covid-19 in countries where different policies of containment were activated. It is known that the growth of pandemic spread at its threshold is exponential, but it is not known how to quantify the success of different containment policies. We identify that a successful approach gives an arrested phase regime following the Ostwald growth, where, over the course of time, one phase transforms into another metastable phase with a similar free energy as observed in oxygen interstitial diffusion in quantum complex matter and in crystallization of proteins. We introduce the s factor which provides a quantitative measure of the efficiency and speed of the adopted containment policy, which is very helpful not only to monitor the Covid-19 pandemic spread but also for other countries to choose the best containment policy. The results show that a policy based on joint confinement, targeted tests, and tracking positive cases is the most rapid pandemic containment policy; in fact, we found values of 9, 5, and 31 for the success s factor for China, South Korea, and Italy, respectively, where the lowest s factor indicates the best containment policy.

scholarly journals Data analysis on Coronavirus spreading by macroscopic growth laws

2020 ◽  
Vol 31 (07) ◽  
pp. 2050103 ◽  
Author(s):  
P. Castorina ◽  
A. Iorio ◽  
D. Lanteri
Keyword(s):  
Growth Rate ◽  
Data Analysis ◽  
South Korea ◽  
Time Evolution ◽  
Epidemic Spreading ◽  
Daily Data ◽  
Large Growth ◽  
Gompertz Law ◽  
Growth Laws ◽  
Containment Policy

To evaluate the effectiveness of the containment on the epidemic spreading of the new Coronavirus disease 2019, we carry on an analysis of the time evolution of the infection in a selected number of different Countries, by considering well-known macroscopic growth laws, the Gompertz law, and the logistic law. We also propose here a generalization of Gompertz law. Our data analysis permits an evaluation of the maximum number of infected individuals. The daily data must be compared with the obtained fits, to verify if the spreading is under control. From our analysis, it appears that the spreading reached saturation in China, due to the strong containment policy of the national government. In Singapore a large growth rate, recently observed, suggests the start of a new strong spreading. For South Korea and Italy, instead, the next data on new infections will be crucial to understand if the saturation will be reached for lower or higher numbers of infected individuals.

scholarly journals Epidemic spreading model in heterogeneous conditions

2021 ◽  
pp. 1-12
Author(s):  
Andrey Viktorovich Podlazov
Keyword(s):  
Equilibrium Position ◽  
Sir Model ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Oscillatory Dynamics ◽  
Spreading Model ◽  
Multiple Contacts ◽  
The Social

I propose two modifications of the SIR model of the epidemic spread, taking into account the social and space heterogeneity of the population. Social hetero¬geneity associated with differences in the intensity of paired contacts between people qualitatively changes the basic reproductive number. Space heterogeneity associated with differences in the intensity of multiple contacts between people significantly shifts the equilibrium position, increases the characteristic times and leads to the emergence of oscillatory dynamics of finite duration.

scholarly journals Discovering Correlations between the COVID-19 Epidemic Spread and Climate

2020 ◽  
Vol 17 (21) ◽  
pp. 7958 ◽  
Author(s):  
Shaofu Lin ◽  
Yu Fu ◽  
Xiaofeng Jia ◽  
Shimin Ding ◽  
Yongxing Wu ◽  
...  
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Virus Disease ◽  
Newly Diagnosed ◽  
Epidemic Spread ◽  
Prevention Measures ◽  
Epidemic Spreading ◽  
Corona Virus ◽  
The World

The outbreak of Corona Virus Disease 2019 (COVID-19) has affected the lives of people all over the world. It is particularly urgent and important to analyze the epidemic spreading law and support the implementation of epidemic prevention measures. It is found that there is a moderate to high correlations between the number of newly diagnosed cases per day and temperature and relative humidity in countries with more than 10,000 confirmed cases worldwide. In this paper, the correlation between temperature/relative humidity and the number of newly diagnosed cases is obvious. Governments can adjust the epidemic prevention measures according to climate change, which will more effectively control the spread of COVID-19.

scholarly journals Epidemic spreading and control strategies in spatial modular network

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Bnaya Gross ◽  
Shlomo Havlin
Keyword(s):  
Nearest Neighbor ◽  
Control Strategies ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Modular Network ◽  
Global Epidemic ◽  
Modular Model ◽  
Entire Country ◽  
Global Spread ◽  
And Control

AbstractEpidemic spread on networks is one of the most studied dynamics in network science and has important implications in real epidemic scenarios. Nonetheless, the dynamics of real epidemics and how it is affected by the underline structure of the infection channels are still not fully understood. Here we apply the susceptible-infected-recovered model and study analytically and numerically the epidemic spread on a recently developed spatial modular model imitating the structure of cities in a country. The model assumes that inside a city the infection channels connect many different locations, while the infection channels between cities are less and usually directly connect only a few nearest neighbor cities in a two-dimensional plane. We find that the model experience two epidemic transitions. The first lower threshold represents a local epidemic spread within a city but not to the entire country and the second higher threshold represents a global epidemic in the entire country. Based on our analytical solution we proposed several control strategies and how to optimize them. We also show that while control strategies can successfully control the disease, early actions are essentials to prevent the disease global spread.

Directed Growth of Ferrite in Austenite and Kurdjumov-Sachs Orientation Relationship

2012 ◽  
Vol 715-716 ◽  
pp. 128-133
Author(s):  
Dong Nyung Lee ◽  
Heung Nam Han
Keyword(s):  
Growth Rate ◽  
Orientation Relationship ◽  
Strain Energy ◽  
Lattice Mismatch ◽  
Solid Phase ◽  
Metastable Phase ◽  
Maximum Growth ◽  
Growth Direction ◽  
Stable Phase ◽  
Directed Growth

The solid phase transformation of a metastable phase into a stable phase needs the activation energy. The energy is usually supplied in the form of thermal energy. When the nucleation takes place, the strain energy may develop in the metastable matrix and the stable nucleus. The strain energy can result from differences in density of the nucleus and matrix and the lattice mismatch between the nucleus and matrix. The stable-metastable interface region has the highest strain-energy density in the maximum Youngs modulus direction of the stable phase. Accordingly, the growth rate of the stable phase is the highest in its highest Youngs modulus directions. As the transformation temperature decreases, the strain energy contribution increases and the growth rate anisotropy is likely to increase. When austenite transforms into ferrite at low temperatures, the directed growth of ferrite is observed as forms of Widmanstätten ferrite plates and acicular ferrite plates. The maximum growth direction of ferrite is along the maximum Youngs modulus direction of ferrite, <111>α, and the broad interfaces are parallel to the maximum growth direction and formed so that they minimizes the shear strain energy in the interface layer. The directed growth results in the Kurdjumov-Sachs orientation relationship between austenite and ferrite, <111>α//<110>γand {110}α//{111}γ.

scholarly journals Sick and edgy: walk-counting as a metric of epidemic spreading on networks

2008 ◽  
Vol 6 (39) ◽  
pp. 897-907 ◽  
Author(s):  
Dennis C. Wylie ◽  
Wayne M. Getz
Keyword(s):  
Structural Properties ◽  
Network Structure ◽  
Adjacency Matrix ◽  
Degree Distribution ◽  
Structured Populations ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Spreading Process ◽  
Dynamic Pattern ◽  
General Network

A network structure metric is herein suggested for the investigation of the behaviour of epidemic spreading processes in general network-structured populations. This simple measure, based on the algebraic powers of the adjacency matrix associated with the network in question, is shown to admit a heuristic interpretation as a representation of a spreading process similar to standard epidemic models. It is further shown that the values of this metric may be of use in understanding the dynamic pattern of epidemic spread on networks of greatly varying structural properties (e.g. the degree distribution, the assortativity/dissortativity and the clustering).

scholarly journals Pertumbuhan Ekonomi Provinsi Kepulauan Riau

2018 ◽  
Vol 2 (1) ◽  
pp. 52-63
Author(s):  
Elvina Safitri
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
Quantitative Measure ◽  
Secondary Data ◽  
Retail Trade ◽  
Analysis Method ◽  
Economic Activities ◽  
Descriptive Data ◽  
Goods And Services ◽  
Data Source

Economic growth as a quantitative measure that describes the development of an economy in a given year when compared with the previous year. Economic growth means the development of economic activities that cause goods and services produced in the community to increase and the welfare of society increases. Each region seeks to increase economic growth and stability, one of which is Riau Islands Province. To see how the economic growth of Riau Islands Province, then conducted a study entitled Economic Growth Riau Islands Province. The data source used is secondary data with descriptive data analysis method. From the analysis, it is known that the economic growth of Kepulauan Riau Province in the year of 2016 is 5.03% with the highest growth rate in the big and retail trade, car and motorcycle repairs 9.54%.

scholarly journals Markovian Random Walk Modeling and Visualization of the Epidemic Spread of COVID-19

2020 ◽  
Author(s):  
Haluk Akay ◽  
George Barbastathis
Keyword(s):  
Random Walk ◽  
Population Density ◽  
South Korea ◽  
Respiratory Illness ◽  
Sir Model ◽  
Epidemic Spread ◽  
Epidemic Spreading ◽  
Susceptible Population ◽  
The World ◽  
Viral Respiratory

AbstractThe epidemic spread of CoVID-19 has resulted in confirmed cases of viral respiratory illness in more than 1.4 million people around the world as of April 7th, 2020 [1]. However, different regions have experienced the spread of this disease differently. Here, we develop a Markovian random-walk spatial extension of a quarantine-enhanced SIR model to measure, visualize and forecast the effect of susceptible population density, testing rate, and social distancing and quarantine policies on epidemic spreading. The model is used to simulate the spread of CoVID-19 in the regions of Hubei, China; South Korea; Iran; and Spain. The model allows for evaluating the results of different policies both quantitatively and visually as means of better understanding and controlling the spread of the disease.

Microstructure Evolution in Nb-12Si-22Ti-14Cr-2Al2Hf Alloy Fabricated by Directional Solidification

2014 ◽  
Vol 33 (6) ◽  
pp. 495-498 ◽  
Author(s):  
Linfen Su ◽  
Lina Jia ◽  
Sainan Yuan ◽  
Huarui Zhang ◽  
Hu Zhang
Keyword(s):  
Growth Rate ◽  
Steady State ◽  
Directional Solidification ◽  
Microstructure Evolution ◽  
Metastable Phase ◽  
High Growth ◽  
High Growth Rate ◽  
Quasi Steady State ◽  
Growth Region ◽  
State Growth

AbstractIn this work, the microstructure evolution of the Nb-12Si-22Ti-14Cr-2Al-2Hf alloy (at.%) fabricated by liquidmetal-cooled directional solidification (LMC) was investigated and the solidification behaviors were discussed. The results revealed that the growth rate was of crucial in controlling the microstructure of this alloy and the higher growth rate was beneficial to the formation of metastable phase Nb3Si. The microstructure of non-melted region consisted of NbSS dendrites, NbSS/Nb5Si3 eutectics and Ti-rich NbSS/Cr2Nb eutectics while the microstructure of quasi-steady-state growth region of this alloy consisted of NbSS dendrites, Nb3Si laths and Ti-rich NbSS/Cr2Nb eutectic. Nb3Si had the advantage of nucleation at medium/high growth rate. Therefore, the microstructure evolution occurred in this study was owing to the increase of growth rate.

scholarly journals Simulation of crystal growth in multicomponent metastable alloys

2020 ◽  
Vol 62 (12) ◽  
pp. 943-949
Author(s):  
M. V. Dudorov ◽  
V. E. Roshchin
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Diffusion Processes ◽  
Mutual Influence ◽  
Crystallization Front ◽  
Metastable Phase ◽  
Phase Interface ◽  
Primary Crystallization ◽  
High Rate ◽  
Silicon Concentration

A method for predicting the regularities of crystal growth from metastable melts has been developed. The process of crystal growth from a multicomponent melt is described by the methods of nonequilibrium thermodynamics, taking into account the mutual influence of thermal and diffusion processes. The application of a new variational approach to the constructed system of equations made it possible to obtain expressions of the crystal growth rate from a multicomponent melt convenient for practical calculations. The obtained technique allowed us to analyze the features of crystal growth at high rate of crystallization front, which leads to “impurity capture” effect – deviation from equilibrium conditions at the phase interface. The developed mathematical model makes it possible to calculate the growth rate of new phase particles and to estimate the effect of metastable effects on deviation of the components’ concentration at surface of the growing crystal from equilibrium values. Thus, using the obtained method, a “metastable” phase diagram of the system under study can be constructed. The developed approach is applied to the calculation of growth of α-Fe(Si) nanocrystals during annealing of amorphous alloy Fe73,5 Cu1 Nb3 Si13,5B9. The calculation results were compared with the results of the experiment on the alloy primary crystallization. It is shown that the concentration of Fe at the surface of the growing crystal does not significantly deviate from the equilibrium values. On the other hand, silicon atoms are captured by the crystallization front, silicon concentration at the surface of the growing nanocrystal deviates significantly from equilibrium values. The calculation has shown that after the initial crystallization of the amorphous phase, occurring at a temperature of 400 – 450 °C, the deviation of silicon concentration from equilibrium value is about 2 %, while this equilibrium value is about 13.3 %.

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