scholarly journals Interrelation of processing modes with the current parameters of the contact zone during thermofriction processing

2018 ◽  
Vol 224 ◽  
pp. 01132 ◽  
Author(s):  
Nikolay Pokintelitsa
Keyword(s):  
Contact Zone ◽  
Rotating Disk ◽  
Flat Surfaces ◽  
Material Layer ◽  
Control Actions ◽  
Disk Tool ◽  
Processing Modes ◽  
Cutting Modes

The establishment of the interrelation between the processing modes and the current parameters of the contact zone during the thermofriction processing of flat surfaces of workpieces by a rotating disk tool is considered. Dependencies are presented allowing assignment of cutting modes, prediction of the size of the removed material layer, and determination of the control actions value.

Spin Coating Planarization Of Integrated Circuit Topography On A Rotating Disk

1991 ◽  
Vol 227 ◽  
Author(s):  
Roger K. Yonkoski ◽  
David S. Soane
Keyword(s):  
Experimental Data ◽  
Fluid Flow ◽  
Integrated Circuit ◽  
Spin Coating ◽  
Rotating Disk ◽  
Momentum Conservation ◽  
Flat Surfaces ◽  
Determination Of Parameters ◽  
Polyimide Precursor

ABSTRACTPolyimide is commonly used in the microelectronic industry for interconnection applications because of its ability to planarize features typically found on an IC chip. A mathematical model is developed to describe fluid flow on a rotating disk based on the principles of mass and momentum conservation. Constitutive relationships necessary for this model are proposed. Experimental data for polyimide precursor solutions are presented which enable the determination of parameters for the constitutive equations. This model is used to describe the film profiles over flat surfaces and near micron-sized features. Attention is focused on the coupling between mass transport and fluid flow as well as the effects of surface tension on film profiles over topographical features.

scholarly journals A Control Based Mathematical Model for the Evaluation of Intervention Lines in COVID-19 Epidemic Spread: The Italian Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Paolo Di Giamberardino ◽  
Rita Caldarella ◽  
Daniela Iacoviello
Keyword(s):  
Mathematical Model ◽  
Equilibrium Points ◽  
Italian Case ◽  
Control Actions ◽  
Containment Measures ◽  
Asymptomatic Subjects ◽  
The Impact

This paper addresses the problem of describing the spread of COVID-19 by a mathematical model introducing all the possible control actions as prevention (informative campaign, use of masks, social distancing, vaccination) and medication. The model adopted is similar to SEIQR, with the infected patients split into groups of asymptomatic subjects and isolated ones. This distinction is particularly important in the current pandemic, due to the fundamental the role of asymptomatic subjects in the virus diffusion. The influence of the control actions is considered in analysing the model, from the calculus of the equilibrium points to the determination of the reproduction number. This choice is motivated by the fact that the available organised data have been collected since from the end of February 2020, and almost simultaneously containment measures, increasing in typology and effectiveness, have been applied. The characteristics of COVID-19, not fully understood yet, suggest an asymmetric diffusion among countries and among categories of subjects. Referring to the Italian situation, the containment measures, as applied by the population, have been identified, showing their relation with the government's decisions; this allows the study of possible scenarios, comparing the impact of different possible choices.

The Evaporation of Water from Helix Aspersa

1964 ◽  
Vol 41 (4) ◽  
pp. 783-792
Author(s):  
JOHN MACHIN
Keyword(s):  
Air Flow ◽  
Complex Form ◽  
Ambient Air ◽  
Helix Aspersa ◽  
Flat Surfaces ◽  
Wind Speeds ◽  
Low Wind Speeds ◽  
Rate Of Evaporation ◽  
Snail Helix Aspersa

1. The construction and use of a wind-tunnel apparatus is described in which measurements of evaporation under controlled conditions of temperature, humidity and air flow can be made. 2. Two mathematical formulae, applicable to evaporation in relatively low wind speeds, are described. It is suggested that a promising approach to evaporation from moist-skinned animals is provided by the application of Leighly's formula: E = K(p0-pd)c(v/x)n, where the rate of evaporation (E) is expressed in terms of the vapour pressure at the evaporating surface (p0) and in the ambient air (pd), the wind speed (v) and the length of the evaporating surface parallel to the wind (x). The constant, K, is calculated independently and the terms n and c are left for empirical determination. 3. Values of n and c for different types of evaporating surface are given together with the method used in their calculation. Those relating to flat evaporators and to the snail, Helix aspersa, are shown to differ significantly. 4. In general n increases and c decreases as the amount of air disturbance caused by the snail increases. 5. The fact that n for flat surfaces is in good agreement with previously established theory is taken as evidence that Leighly's formula may be validly applied. 6. The combined determination of n and c is introduced as a convenient assessment of a complex form in terms of air flow and evaporation.

scholarly journals Determination of seismogenic interplate contact zone and crustal seismicity around Antofagasta, northern Chile using local data

1994 ◽  
Vol 116 (3) ◽  
pp. 553-561 ◽  
Author(s):  
D. Comte ◽  
M. Pardo ◽  
L. Dorbath ◽  
C. Dorbath ◽  
H. Haessler ◽  
...  
Keyword(s):  
Contact Zone ◽  
Northern Chile ◽  
Local Data

scholarly journals Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

2015 ◽  
Vol 4 (3) ◽  
pp. 326 ◽  
Author(s):  
Hayder A. Abdul Bari ◽  
Zainab Yousif ◽  
Zulkefli Bin Yaacob ◽  
Edward Oluwasogaakindoyo
Keyword(s):  
Drag Reduction ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Aggregate Structure ◽  
Surfactant Micelle ◽  
Micro Particles ◽  
Transmission Electron ◽  
Speed Up ◽  
Reduction Characteristics

<p>This paper focuses on the determination of the interaction between polymer (Polyacrylamide (PAM)) and surfactant (Sodium dod benzene sulfonate (SDBS)) as a drag reducer using Rotating Disk apparatus (RDA) at various concentrations (500, 700, 1000, 1500 and 2000) ppm individually and in the combined form under turbulent conditions at different rotation speed up to 3000 rpm, as well as studying their mechanisms as a drag reducer. The results show that the maximum percent drag reduction increases to (40, 41, 43, 45 and 48)% by using the combined additives of surfactant and polymer at the above concentrations respectively, with slower degradation and display drag reduction for a larger range of Reynolds numbers. The nano and micro particles formed from the combined PAA and SDBSA was studied using cryo-transmission electron microscopy (cryo-TEM) techniques. The images show the surrounding of polymer chain to the surfactant micelle to form an aggregate structure. A hexagonal crystalline form was suggested to describe the shape of the aggregate structure.</p>

Research on Fuel Migration Phenomenon in the Sintering Process

2013 ◽  
Vol 634-638 ◽  
pp. 857-863
Author(s):  
Ya Ping Mo ◽  
De Qing Zhu ◽  
Jun Li
Keyword(s):  
Grain Size ◽  
Solid Fuel ◽  
Fine Particles ◽  
Vertical Direction ◽  
Size Composition ◽  
Fuel Particle ◽  
Sintering Process ◽  
Material Layer ◽  
Flow Through

In this paper, we use the research methods of sintering cup.On the basis of the determination of solid fuel particle size composition and the distribution in the mixture. During the sintering process, respectively, 5min, 10min, 15min, 20min interrupt the test, by dectecting the distribution of solid fuel in the mixture to study the migration phenomenon of solid fuel during the sintering process. The results showed that: during the sintering process, the main migration of the fuel is the migration of fine particles, including the fuel migration of 0.25-0.5mm grain size, part of the 0.5-1mm grain size and a small amount of-0.25mm grain size,but most of the fuel migrated will be re-adsorbed, about 0.11% of the fuel with the air flow through the material layer, the migration of fuel to ease the state of segregation in the vertical direction along the material layer, so that cause actual participation in the combustion of the fuel content in line along the height direction of the material layer.

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