Lattice Heat Capacity of Mesoscopic Nanostructures

We present a rigorous full quantum mechanical model for the lattice heat capacity of mesoscopic nanostructures in various dimensions. Model can be applied to arbitrary nanostructures with known vibrational spectrum in zero, one, two, or three dimensions. The limiting case of infinitely sized multi-dimensional materials are also found, which are in agreement with well-known results. As examples, we obtain the heat capacity of fullerenes

Bipolar Transistor Based on Graphane

Graphane is a semiconductor with an energy gap, obtained from hydrogenation of the two-dimensional grapheme sheet. Together with the two-dimensional geometry, unique transport features of graphene, and possibility of doping graphane, p and n regions can be defined so that p-n junctions become feasible with small reverse currents. Our recent analysis has shown that an ideal I-V characteristic for this type of junctions may be expected. Here, we predict the behavior of bipolar juncrion transistors based on graphane. Profiles of carriers and intrinsic parameters of the graphane transistor are calculated and discussed

Three-dimensional accelerating AdS black holes in F(R)F(R) gravity

Considering a three-dimensional $C-$metric, we obtain the exact accelerating black holes in the $F(R)$ theory of gravity coupled with and without a matter field. First, we extract uncharged accelerating AdS black hole solutions in $F(R)$ gravity. Then, we study the effects of various parameters on metric function, roots, and the temperature of these black holes. The temperature is always positive for the radii less than $\frac{1}{\alpha }$, and it is negative for the radii more than $\frac{1}{\alpha }$. We extend our study by coupling nonlinear electrodynamics as a matter filed to $F(R)$ gravity to obtain charged black holes in this theory. Next, we evaluate the effects of different parameters such as the electrical charge, accelerating parameter, angular, $F(R)$ gravity, and scalar curvature on the obtained solutions, roots, and temperature of three-dimensional charged accelerating AdS black holes. The results indicate that there is a root in which it depends on various parameters. The temperature of these black holes is positive after this root.Comment: 11 pages, 3 figure

Comparison between in vitro and in vivo antibacterial activity of Curcuma zedoaria from Malaysia

The antimicrobial activity of the extracts of Curcuma zedoaria from Malaysia was compared using in vitro and in vivo systems. The comparison was performed against four bacterial strains including two gram negative strains (Escherichia coli and Pseudomonas aeruginosa) and two gram positive strains (Bacillus cereus and Staphylococcus aureus) using the agar well diffusion method. Petroleum ether, chloroform and methanol were used as solvents for preparing the plant extracts. Growth hormones namely indole-3-butyric acid (IBA) and 6-Benzylaminopurine (BAP) were used in the in vitro system separately between the range of 0.25 and 3.5 mg/l for IBA and 0.5 and 4 mg/l for BAP and a mix formula containing both hormones using the best ranges after rapid tests. The results showed that the in vitro system was more capable of inhibiting S. aureus growth compared with in vivo system on the agar plate. P. aeruginosa and E. coli growth were only inhibited by the in vitro system on the agar plate, while B. cereus was the only strain in the in vivo system which produced higher inhibition zone on the agar plate against its growth compared with the in vitro system.Key words: Curcuma zedoaria, antibacterial activity

Mechanical Properties of Boehmite Evaluated by Atomic Force Microscopy Experiments and Molecular Dynamic Finite Element Simulations

Boehmite nanoparticles show great potential in improving mechanical properties of fiber reinforced polymers. In order to predict the properties of nanocomposites, knowledge about the material parameters of the constituent phases, including the boehmite particles, is crucial. In this study, the mechanical behavior of boehmite is investigated using Atomic Force Microscopy (AFM) experiments and Molecular Dynamic Finite Element Method (MDFEM) simulations. Young's modulus of the perfect crystalline boehmite nanoparticles is derived from numerical AFM simulations. Results of AFM experiments on boehmite nanoparticles deviate significantly. Possible causes are identified by experiments on complementary types of boehmite, that is, geological and hydrothermally synthesized samples, and further simulations of imperfect crystals and combined boehmite/epoxymodels. Under certain circumstances, the mechanical behavior of boehmite was found to be dominated by inelastic effects that are discussed in detail in the present work. The studies are substantiated with accompanying X-ray diffraction and Raman experiments.DFG/FOR/202

Life Cycle Assessment of Municipal Waste Management System (Case Study: Karaj, Iran)

LCA has been defined as a tool for evaluating the environmental burdens and potential impacts that can be applied to municipal solid waste management systems for determine the optimum municipal solid waste (MSW) management strategy.To investigate the Waste Management system strategy of Karaj City we used LCA method. Three scenarios were defined and compared based on environmental burden include water pollution, air pollution, consumed energy and waste residues.. For each of these scenarios, an ecological indicator was achieved from checklist values. From the environmental point of view, results show that recycling is one of the best alternatives for Waste Management. Furthermore, composting has an important role in alleviating the load of pollutants and energy usage in the Waste Management system

Types of neural guides and using nanotechnology for peripheral nerve reconstruction

Peripheral nerve injuries can lead to lifetime loss of function and permanent disfigurement. Different methods, such as conventional allograft procedures and use of biologic tubes present problems when used for damaged peripheral nerve reconstruction. Designed scaffolds comprised of natural and synthetic materials are now widely used in the reconstruction of damaged tissues. Utilization of absorbable and nonabsorbable synthetic and natural polymers with unique characteristics can be an appropriate solution to repair damaged nerve tissues. Polymeric nanofibrous scaffolds with properties similar to neural structures can be more effective in the reconstruction process. Better cell adhesion and migration, more guiding of axons, and structural features, such as porosity, provide a clearer role for nanofibers in the restoration of neural tissues. In this paper, basic concepts of peripheral nerve injury, types of artificial and natural guides, and methods to improve the performance of tubes, such as orientation, nanotechnology applications for nerve reconstruction, fibers and nanofibers, electrospinning methods, and their application in peripheral nerve reconstruction are reviewed