2,155 research outputs found
Multiscale modeling of heat conduction in graphene laminates
We developed a combined atomistic-continuum hierarchical multiscale approach
to explore the effective thermal conductivity of graphene laminates. To this
aim, we first performed molecular dynamics simulations in order to study the
heat conduction at atomistic level. Using the non-equilibrium molecular
dynamics method, we evaluated the length dependent thermal conductivity of
graphene as well as the thermal contact conductance between two individual
graphene sheets. In the next step, based on the results provided by the
molecular dynamics simulations, we constructed finite element models of
graphene laminates to probe the effective thermal conductivity at macroscopic
level. A similar methodology was also developed to study the thermal
conductivity of laminates made from hexagonal boron-nitride (h-BN) films. In
agreement with recent experimental observations, our multiscale modeling
confirms that the flake size is the main factor that affects the thermal
conductivity of graphene and h-BN laminates. Provided information by the
proposed multiscale approach could be used to guide experimental studies to
fabricate laminates with tunable thermal conduction properties
Mechanical properties and thermal conductivity of graphitic carbon nitride: A molecular dynamics study
Graphitic carbon nitride nanosheets are among 2D attractive materials due to
presenting unusual physicochemical properties.Nevertheless, no adequate
information exists about their mechanical and thermal properties. Therefore, we
used classical molecular dynamics simulations to explore the thermal
conductivity and mechanical response of two main structures of single-layer
triazine-basedg-C3N4 films.By performing uniaxial tensile modeling, we found
remarkable elastic modulus of 320 and 210 GPa, and tensile strength of 47 GPa
and 30 GPa for two different structures of g-C3N4sheets. Using equilibrium
molecular dynamics simulations, the thermal conductivity of free-standing
g-C3N4 structures were also predicted to be around 7.6 W/mK and 3.5 W/mK. Our
study suggests the g-C3N4films as exciting candidate for reinforcement of
polymeric materials mechanical properties
Actinomycosis may be presented in unusual organs: A report of two cases
Actinomycosis is a chronic granulomatous suppurative disease characterized by direct extension to the contagious tissue with the formation of multiple drainage sinus tracts through which tiny colonies of organisms called sulfur granules are discharged. Here, we report 2 cases of actinomycosis from Iran. One of them had actinomycosis on the hand and the other on the foot. Samples of tissue biopsy showed sulfur granules associated with colonies of actinomyces, thus confirming the diagnosis in both cases. The response to curettage and penicillin therapy was satisfactory in our patients. The chronic and indolent course of actinomycosis resembles tuberculosis, fungal infection and malignancy. So, increasing awareness among the clinicians and clinical microbiologists will help in the early diagnosis of the disease and in the initiation of early and proper treatment
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