scholarly journals Numerical simulation of the influence of pores sizes on moisture migration dynamic in masonry wall

2021 ◽  
Vol 10 (2) ◽  
pp. 164
Author(s):  
N. M. Nde ◽  
D. Fokwa ◽  
M. Mbessa ◽  
T. T. Tamo ◽  
C. Pettang
Keyword(s):  
Numerical Simulation ◽  
Pore Size ◽  
Masonry Wall ◽  
Moisture Gradient ◽  
Concrete Wall ◽  
Significant Deterioration ◽  
Moisture Migration ◽  
New Construction ◽  
Building Walls ◽  
Kinetics Of

The sometimes extreme hydro-climatic stresses that buildings undergo can lead to significant deterioration which can lead to their collapse. The concern to realize durable works and ensuring a comfortable framework for the life of occupants leads to seek effective solutions, as well for the new construction as for the renovation of old construction, answering the sempiternal problem of harmful action of water on buildings materials. This paper proposes a numerical simulation of moisture migration in concrete building walls, the aim being to highlight the influence of pore size on the kinetics of moisture migration, and its gradient in the wall. A mathematical model taking into account the mechanisms of moisture migration due to liquid moisture gradient and by vapor diffusion is proposed; the discrete formulation of the equa-tion by the numerical scheme of Crank Nicolson is then carried out, and results from computer modeling using Matlab software version 7.10.0.499 (R2010a), show that pore size is a key parameter that influences the dynamics of moisture migration in the wall. Indeed, this parameter qualitatively and quantitatively influences the kinetics of moisture migration, as well as it gradient in the concrete wall. It appears a greater migration dynamic when the pores sizes decrease, means a greater kinetics of moisture migration and lower moisture gradient in the walls at the hygrometric equilibrium, for a decreasing pore size. 

scholarly journals Numerical Simulation Model for Granulation Kinetics of Iron Ores

2005 ◽  
Vol 45 (4) ◽  
pp. 500-505 ◽  
Author(s):  
Junya KANO ◽  
Eiki KASAI ◽  
Fumio SAITO ◽  
Takazo KAWAGUCHI
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Iron Ores ◽  
Kinetics Of

scholarly journals Kinetics of the active media of nuclear-pumped lasers

1993 ◽  
Vol 11 (4) ◽  
pp. 655-661 ◽  
Author(s):  
A.M. Boichenko ◽  
A.V. Karelin ◽  
O.V. Sereda ◽  
S.I. Yakovlenko
Keyword(s):  
Numerical Simulation ◽  
High Power ◽  
Short Wavelength ◽  
Noble Gases ◽  
Excimer Lasers ◽  
Active Media ◽  
Metal Vapors ◽  
Kinetics Of

Numerical simulation of active media nuclear-pumped lasers on noble gases and their mixtures with metal vapors are presented. Prospects of creation of high-power short-wavelength nuclear-pumped excimer lasers are discussed.

Numerical simulation of impact loading for reinforced concrete wall

2018 ◽  
Vol 167 ◽  
pp. 66-71 ◽  
Author(s):  
H. Takazawa ◽  
K. Hirosaka ◽  
K. Miyazaki ◽  
N. Tohyama ◽  
S. Saigo ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Wall ◽  
Reinforced Concrete Wall

Monodisperse Mesoporous Microparticles Prepared by Evaporation-Induced Self Assembly Within Aerosols

2003 ◽  
Vol 775 ◽  
Author(s):  
Shailendra Rathod ◽  
G. V. Rama Rao ◽  
Brett Andrzejewski ◽  
Gabriel P. López ◽  
Timothy L. Ward ◽  
...  
Keyword(s):  
Pore Size ◽  
Self Assembly ◽  
Swelling Agent ◽  
Aerosol Generator ◽  
Amphiphilic Molecules ◽  
Brij 58 ◽  
Evaporation Induced Self Assembly ◽  
Uptake Process ◽  
Hexagonally Ordered ◽  
Kinetics Of

AbstractEvaporation induced self assembly (EISA) within microdroplets produced by a vibrating orifice aerosol generator (VOAG) has been used to produce monodisperse mesoporous silica particles. This process exploits the concentration of evaporating droplets to induce the organization of various amphiphilic molecules, effectively partitioning the silica precursor (TEOS) to the hydrophilic regions of the structure. Promotion of silica condensation, followed by removal of the surfactant, provides ordered spherical mesoporous particles. Using the VOAG we have produced highly monodisperse particles in the 5 to 10 μm diameter range. The cationic surfactant CTAB typically leads to hexagonal mesostructure with mean pore size of about 2 nm and specific surface area around 900 m2/g. We have also shown that the pore size in CTABtemplated particles can be increased to 3.8 nm by incorporating trimethylbenzene as a swelling agent. The TMB prefentially locates inside and swells the hydrophobic regions of the surfactant mesostructure. Pore size can also be varied by the choice of amphiphile. Hexagonally ordered particles have been produced using the nonionic surfactant Brij-58 and block copolymer F127. These powders possessed mean pore size 2.8 nm and 6.9 nm, respectively. The uptake of alkyl pyridinium chloride molecules have recently been measured, revealing an uptake capacity that is explained by surface adsorption (as opposed to simple pore infiltration). Kinetics of the uptake process are still be analyzed.

Numerical Analysis of Nuclear Facility Reinforced Concrete Wall and Roof Slab Behavior Under Close-in Explosions

2020 ◽  
Author(s):  
Li Rongpeng ◽  
Li Yumin ◽  
Sui Chunguang ◽  
Jiang Di
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Simulation Method ◽  
Concrete Slabs ◽  
Nuclear Facilities ◽  
Concrete Wall ◽  
Empirical Formulas ◽  
Air Overpressure ◽  
Reinforced Concrete Slabs ◽  
Reinforced Concrete Wall

Abstract With the change of anti-terrorism situation, civil unmanned aerial vehicles carrying small equivalent of explosives may cause damage to the reinforced concrete wall or roof of nuclear facilities at close range. Existing research has mostly focused on the overall damage caused by large equivalent explosives at medium and long distances. In this paper, the air overpressure peak curve and behavior of reinforced concrete slabs under small equivalent TNT close-in explosion conditions are calculated by numerical simulation methods and compared with empirical formulas and experimental results in the literature to verify. Furthermore, the numerical simulation method was used to evaluate the resistance of 300mm thick reinforced concrete slabs to close-in impacts of different mass TNT at a standoff distance of 0.4m.

scholarly journals Phase Change Material Used for Masonry Joints: Numerical Simulation and Scale Test

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 16
Author(s):  
Jiang ◽  
Liu ◽  
Yuan
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Masonry Wall ◽  
Wall Structure ◽  
Thermal Coefficient ◽  
New Form ◽  
Change Material

In order to effectively improve the thermal performance of the thermal insulation masonry wall, the thermal bridge effect of the grey joint on the heat transfer of the wall structure was studied. A brand-new form of phase change material walls, which used phase change materials in the wall parts to build ash joints, was carried out. The application of phase change material mortar, which was different from conventional "Hamburger" phase change material walls, was demonstrated to be a useful tool to reduce the thermal coefficient of the masonry wall. Furthermore, the scale-down test and numerical simulation of the heat transfer coefficient of the phase change material wall with different distribution of ash joints were experimented and discussed, and the feasibility of the new-form phase change material wall within the error range was verified.

Investigation on optimal active layer thickness and pore size in dual-layer NH3-SCR monolith for low SO2 oxidation by numerical simulation

Fuel ◽  
2020 ◽  
Vol 279 ◽  
pp. 118420
Author(s):  
Qi Xin ◽  
Zhesheng Hua ◽  
Yujie Fu ◽  
Yang Yang ◽  
Shaojun Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pore Size ◽  
Layer Thickness ◽  
Active Layer ◽  
Active Layer Thickness ◽  
So2 Oxidation ◽  
Nh3 Scr
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