Electronic and optical properties of 5-AVA-functionalized BN nanoclusters: A DFT study

We carried out detailed density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations upon 5-aminolevulinic acid-functionalized B12N12 and B16N16 nanoclusters with the B3LYP, B3PW91, and PBE methods using the 6-311+G∗∗ basis set. The calculated adsorption energies of 5-aminolevulinic acid with the BN nanoclusters were evaluated at T = 298.15 and 311.15 K in the gaseous and aqueous environments with the B3LYP, B3PW91, and PBE methods. Our results showed that the adsorption of the 5-AVA molecule (NH2 group) with B12N12 is more favorable than-with the B16N16 nanocluster in the gas and solvent phases. It is anticipated that a 5-aminolevulinic acid (5-AVA) drug incorporating BN clusters could find application in drug delivery systems and in biomedical devices. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016

Adsorption and dissociation of H<inf>2</inf> on Pd doped graphene-like SiC sheet

© 2016 Hydrogen Energy Publications LLCDoped porous SiC nanostructures with metallic atoms, nanoclusters and nanoparticles have been recognized as promising materials for hydrogen storage. With this regards transition metal elements are interesting impurities for use as doping. In view of this prospect, a theoretical approach based on density functional theory (DFT) was applied to study of the interaction between hydrogen molecule and a graphene-like SiC sheet doped with palladium atom. We have selected a single graphene-like SiC layer, due to its more surface charge polarization in comparison with pure graphene which makes possible remarkable interactions with adsorbed hydrogen molecules. In our study we have included two different configurations of H2 adsorption: 1) at the first state, hydrogen atoms after adsorption stretched and distance between H[sbnd]H atoms has increased but their chemical bond doesn't break. In this situation a physical adsorption occurred and the binding energy restricts applicable interests where it is appropriate for reversible hydrogen storage; 2) at the second situation, atoms of hydrogen molecule discrete from each other and adsorption occurred in a chemical manner. As instance the when a H2 molecule interact simultaneously with Pd atom and SiC nanosheet, it can be dissociated as in this case a hydrogen atom makes bond with Pd atom and the other can be adsorbed chemically on the SiC nanosheet surface. More details about adsorption mechanism are discussed it the context

ANALISA AGREGAT KASAR SEBAGAI VARIABEL BAHAN CAMPURAN BETON MENGGUNAKAN METODE SNI DAN ACI (Studi Kasus Beton Mutu K-275)

Penelitian ini dilakukan dengan maksud dan tujuan adalah untuk menganalisa dan membandingkan kuat tekan beton yang dapat dicapai menggunakan agregat kasar sumber Padang Ratu, Tegineneng dan Tanjungan. Selain itu juga untuk mengetahui kualitas agregat kasar yang bersumber dari daerah Padang Ratu, Tegineneng dan Tanjungan sebagai bahan campuran beton dengan metode SNI dan ACI. Untuk membandingkan nilai kuat tekan beton yang dihasilkan menggunakan agregat kasar yang bersumber dari daerah Padang Ratu, Tegineneng dan Tanjungan korelasinya terhadap pencapaian mutu beton K-275 atau setara dengan 22,825 Mpa. Penelitian ini menggunakan sampel Uji Silinder diameter 15 cm dan tinggi 30 cm. Pengujian dilakukan saat umur 7, 14, 21 dan 28 dan setiap umur terdiri dari 3 benda uji. Sehingga dibutuhkan 72 benda uji. Dengan 3 variasi penggunaan agregat kasar dari 3 quarry yaitu Tanjungan, Padang Ratu dan Tegineneng menggunakan metode SNI dan ACI. Hasil penelitian menunjukkan bahwa kualitas agregat mempengaruhi mutu beton yang dihasilkan. Hubungan kuat tekan beton dengan umur beton menunjukkan bahwa semakin bertambahnya umur beton, kuat tekan beton meningkat juga. Dari hasil penelitian, beton yang mencapai kuat tekan rencana adalah pada campuran beton  menggunakan agregat kasar Tanjungan dengan umur 28 hari yaitu : 23,10 Mpa (Metode ACI) dan 277,42 Kg/cm2 (Metode SNI)

Adsorption and dissociation of H2 on Pd doped graphene-like SiC sheet

Doped porous SiC nanostructures with metallic atoms, nanoclusters and nanoparticles have been recognized as promising materials for hydrogen storage. With this regards transition metal elements are interesting impurities for use as doping. In view of this prospect, a theoretical approach based on density functional theory (DFT) was applied to study of the interaction between hydrogen molecule and a graphene-like SiC sheet doped with palladium atom. We have selected a single graphene-like SiC layer, due to its more surface charge polarization in comparison with pure graphene which makes possible remarkable interactions with adsorbed hydrogen molecules. In our study we have included two different configurations of H2 adsorption: 1) at the first state, hydrogen atoms after adsorption stretched and distance between HsbndH atoms has increased but their chemical bond doesn't break. In this situation a physical adsorption occurred and the binding energy restricts applicable interests where it is appropriate for reversible hydrogen storage; 2) at the second situation, atoms of hydrogen molecule discrete from each other and adsorption occurred in a chemical manner. As instance the when a H2 molecule interact simultaneously with Pd atom and SiC nanosheet, it can be dissociated as in this case a hydrogen atom makes bond with Pd atom and the other can be adsorbed chemically on the SiC nanosheet surface. More details about adsorption mechanism are discussed it the context. © 2016 Hydrogen Energy Publications LL

Application of Molecular Dynamics in Coating Ag-Conjugated Nanoparticles with Potential Therapeutic Applications

Drug delivery systems may benefit from nanoparticles synthesized using biological methods. While chemical reduction of particles is facilitated by some active compounds present in the bio-extract, other active compounds, with potential therapeutic activities, may be adsorbed onto the surface of nanoparticles. However, the mechanism of bio-based nanoparticle synthesis is still under debate. Here, we first employed a molecular dynamics (MD) approach to theoretically predict the coating of a hypothetical 4.5 nm silver nanoparticle with four selected rosemary (Rosmarinus Officinalis L.) active compounds (rosmanol, isorosmanol, carnosol, and carnosic acid). Analysis of density maps and radial distribution functions (RDF) values suggested that the examined compounds had strong hydrophobic properties and could instantaneously be adsorbed to the nanoparticle surfaces. Next, we experimentally examined the capacity of rosemary leaf extract to synthesize and coat Ag-conjugated nanoparticles. The data obtained from ultraviolet–visible spectroscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy and X-ray powder diffraction analyses confirmed the production of spherical Ag-conjugated nanoparticles with an average size of 12-15 nm, coated with proteins, secondary metabolites and other active compounds. Since this method can predict the dynamic behavior of therapeutic compounds when they are in contact with nanoparticles, we believe it provides a valid and new avenue to designing new therapeutic nanoparticles