Sharif Digital Repository

Inferring the structure of molecular networks from time series protein or gene expression data provides valuable information about the complex biological processes of the cell. Causal network structure inference has been approached using different methods in the past. Most causal network inference techniques, such as Dynamic Bayesian Networks and ordinary differential equations, are limited by their computational complexity and thus make large scale inference infeasible. This is specifically true if a Bayesian framework is applied in order to deal with the unavoidable uncertainty about the correct model. We devise a novel Bayesian network reverse engineering approach using ordinary... 

This paper proposes a new variable frequency zero voltage switching (ZVS) control method for boost converter operating in boundary conduction mode (BCM). The intended method keeps the converter in BCM despide of the load and input voltage variations. This is done by changing switching frequency in a certain specified range. The proposed method can guarantee circuit performance in BCM via zero-crossing detection of the inductor current and changing the switching frequency. In addition, with a slight modification in control structure, it is possible to achieve a fully ZVS in all cases. This converter control is carried out in analog form without using microprocessors which, compared with the... 

The aim of present study is to investigate the convective heat and mass transfer in steady MHD boundary layer flow of an electrically conducting micropolar fluid over an inclined surface. Partial differential equations resulting from the mathematical modeling of the phenomenon are reduce to nonlinear ODEs, and a finite difference based scheme has been adopted to iteratively find the numerical solution by employing the successive over-relaxation (SOR) method. A self-developed computer code has been used in the MATLAB environment. Influence of chemical reaction, Brownian motion, thermophoresis, and viscous dissipation on the relevant features of the flow are discussed and analyzed through... 

The aim of present study is to investigate the convective heat and mass transfer in steady MHD boundary layer flow of an electrically conducting micropolar fluid over an inclined surface. Partial differential equations resulting from the mathematical modeling of the phenomenon are reduce to nonlinear ODEs, and a finite difference based scheme has been adopted to iteratively find the numerical solution by employing the successive over-relaxation (SOR) method. A self-developed computer code has been used in the MATLAB environment. Influence of chemical reaction, Brownian motion, thermophoresis, and viscous dissipation on the relevant features of the flow are discussed and analyzed through... 

This study demonstrates a novel, facile and one-pot approach to synthesize silica nanoparticles with silver at core and crust (SiNP-AgCC). A modified Stöber method was used to make SiNP-AgCC. A significant reduction in the size of SiO2 nanoparticles was seen, with 2–5 nm AgNPs being uniformly distributed on the surface and 10–20 nm AgNPs in the center. A typical mesoporous SiO2 particle (SiNP) produced using the Stöber method was transformed to nanoporous SiO2 by this modified Stöber method. Nanoporous SiO2 particles with silver in the center are advantageous for slow and consistent Ag+ release, which was confirmed by Ag+ ion release test. Antibacterial activities of the samples were tested... 

In this work, poly(vinyl) alcohol (PVA)/poly(ethylene) glycol (PEG) 600 g/mol cross-linked membranes with different alumina (Al2O3) content were synthesized. The membranes were then characterized by FTIR, TGA, DSC, SEM, mechanical strength and permeation properties for carbon dioxide and nitrogen gases at different operating temperatures. The FTIR results confirmed the acetal linkages of cross-linking at 1083 cm−1 and the presence of stretching and bending peaks of Al-O bond at 598 and 444 cm−1, respectively. TGA results showed that the thermal stabilities of the membranes improved with the addition of alumina particles. DSC analysis proved that the glass transition temperature of the... 

NiZn nanoferrites doped with rare-earth cations having stoichiometric composition such as Ni0.5Zn0.5R0.02Fe1.98O4 (R = Tb, Pr, Ce, Gd, Y) were prepared by sol–gel technique. The same amount of Ni and Zn with constant ratio of different rare-earths ions were doped to investigate the variations in the properties. X-ray diffraction (XRD), Field emission electron microscope (FESEM), and vibrating sample magnetometer (VSM) were used to investigate the structure, morphology, and magnetic properties of rare-earth doped NiZn nanoferrites, respectively. X-ray density, bulk density, and porosity were also calculated. Phase, crystallite size, structure, d-spacing, lattice parameter, micro strain, and... 

NiZn nanoferrites doped with rare-earth cations having stoichiometric composition such as Ni0.5Zn0.5R0.02Fe1.98O4 (R = Tb, Pr, Ce, Gd, Y) were prepared by sol–gel technique. The same amount of Ni and Zn with constant ratio of different rare-earths ions were doped to investigate the variations in the properties. X-ray diffraction (XRD), Field emission electron microscope (FESEM), and vibrating sample magnetometer (VSM) were used to investigate the structure, morphology, and magnetic properties of rare-earth doped NiZn nanoferrites, respectively. X-ray density, bulk density, and porosity were also calculated. Phase, crystallite size, structure, d-spacing, lattice parameter, micro strain, and... 

As an important precursor of crystalline phases, amorphous calcium carbonate (ACC), especially ultrasmall ACC clusters, have been attracting great interest in fundamental research, materials chemistry, as well as industrial applications. However, it is still challenging to synthesize stable ACC clusters in water that can be isolated and concentrated without severe aggregation. Herein, we report a facile dialysis method for producing colloidally stable ACC clusters that are well dispersed in water with the protection of specific polycarboxylic acids, which could be also easily deprotected by small-molecule acids like sodium citrate. Inherent proto-calcite short-range order is found to be... 

As an important precursor of crystalline phases, amorphous calcium carbonate (ACC), especially ultrasmall ACC clusters, have been attracting great interest in fundamental research, materials chemistry, as well as industrial applications. However, it is still challenging to synthesize stable ACC clusters in water that can be isolated and concentrated without severe aggregation. Herein, we report a facile dialysis method for producing colloidally stable ACC clusters that are well dispersed in water with the protection of specific polycarboxylic acids, which could be also easily deprotected by small-molecule acids like sodium citrate. Inherent proto-calcite short-range order is found to be... 

In this study, an attempt has been made using different concentrations of rare-earth (RE) elements Yb, Gd in Ni–Zn spinel ferrite to examine the magneto-optical and electrical conductivity analysis of the prepared samples. RE doped Ni–Zn ferrite with composition Ni0.5Zn0.5YbxGdxFe2-xO4 (where, x = 0.00, 0.20, 0.40, 0. 60, 0.80 and 1.00) were prepared by one step sol-gel self-ignition approach. XRD and FESEM were used to examine the formation of a single-phase and variations in the grain size with the increasing contents of RE elements in Ni–Zn ferrite NPs. FTIR confirmed the vibrational studies of the RE doped spinel ferrite. The saturation magnetization, remanence, and coercivity elucidated... 

In this study, an attempt has been made using different concentrations of rare-earth (RE) elements Yb, Gd in Ni–Zn spinel ferrite to examine the magneto-optical and electrical conductivity analysis of the prepared samples. RE doped Ni–Zn ferrite with composition Ni0.5Zn0.5YbxGdxFe2-xO4 (where, x = 0.00, 0.20, 0.40, 0. 60, 0.80 and 1.00) were prepared by one step sol-gel self-ignition approach. XRD and FESEM were used to examine the formation of a single-phase and variations in the grain size with the increasing contents of RE elements in Ni–Zn ferrite NPs. FTIR confirmed the vibrational studies of the RE doped spinel ferrite. The saturation magnetization, remanence, and coercivity elucidated... 

Zeolitic imidazole frameworks (ZIFs) provide an exciting platform to design and fabricate non-precious-metal carbon-based catalysts for oxygen reduction/evolution reaction (ORR/OER). Herein, we elaborately design a facile enzyme-assisted synthetic strategy that enables to tailor the ZIFs precursors into structural stable decussation shape, which derived Co nanoislands grafted on decussate N-doped carbon nanoleaves (D-Co@NC) can well retain the interpenetrating nanostructure. Benefiting from the combined advantages of compositions and interpenetrating nanostructures, D-Co@NC possesses 5.2 times higher exposed electrochemical active area than the conventional dodecahedral one, thus endowing...