Titania nanostructures have been prepared by anodisation in aqueous solution assisted by focused ion beam (FIB) milling. The structures formed are bi-periodic, a disordered “native” nanotube array, with characteristics similar to those formed by the standard anodisation process and an ordered array of tubes with larger diameters, guided by the positioning of the FIB concave pits. Low kV EDX analysis shows implanted Ga in FIB-treated titanium which is efficiently removed by the anodisation process. Following thermal annealing, the FIB-treated regions also crystallise to the same anatase phase as the native regions. This result is in stark contrast to previous FIB-assisted anodisation studies which only produced nanostructured arrays of native dimensions. This singularity is discussed in terms of the stable FIB-induced crystalline defects which, in an aqueous electrolyte, can result in the growth of a weaker barrier layer and larger tubes. This novel process gave hexagonal and square arrays with tailored cross-sectional dimensions and therefore has potential for the synthesis of novel meta-materials.

Grid computing is the collection of computer resources from multiple locations to reach a common goal. The grid is a special type of distributed system with non-interactive workloads that involve a large number of files. Partitioning of the application program/ software into a number of small groups of modules among dissimilar processors is an important parameter to determine the efficient utilization of available resources in a grid computing environment. It also enhances the computation speed. The task partitioning and task allocation activities influence the distributed program/ software properties such as IPC. This paper presents a metaheuristic model, that performs static allocation of a set of “m” modules of distributed tasks/program considering the two conflicting objectives i.e. minimizing the makespan time and balanced utilization of a set of “n” available resources of a grid computing. Experimental results using genetic algorithm indicates that the proposed algorithm achieved these two objectives as well as improve the dynamic heuristics presented in literature.

In the presented work, development of a GUI software package is described which optimizes the Horizontal axis wind turbine blade geometry in accordance to the local air condition. Mainly BEM theory is used to calculate aerodynamic figures. First all the basic theory and governing equations are discussed in detail. A database of local air properties of different locations of India and a number of NERL S-series airfoil’s aerodynamics database is used. A pseudo code is also included in the appendix. Outcome of the package is a Stereo Lithography*.STL formatted CAD geometry file which can be readily exported to any Modeling package like ANSYS geometry modeler where the rotor blade model can be meshed after minor modification for full CFD validation of the result came from BEM theory.

Acacia tortilis is one of the important species of genus Acacia belonging to family Leguminaceae. Though there is no more study performed on this plant but it plays important role in the countries where it found. These countries includes North Africa, Arabian Peninsula and Asian countries including India, Pakistan The various part of Acacia tortilis plant say leaves, pods, gum exudates and bark is found to be beneficial for the purpose of commercially as well as medicinally . Commercially tannins derived from the bark part used as a dyestuff, pods and gum are used as a food, and leaves are useful for land fertility and cattle’s grazing whereas medicinally it is useful for the treatment of various diseases like skin allergy, diabetes, diuretic and hypertension. Vast tract of the dry land in the world lie barren due to the scanty and uneven distribution of rainfall in this part of the world. Acacia and its various species including Acacia tortilis are drought resistant plant; these species are mainly found in arid and sub-arid area of Africa, Arabian and Asia. The survival of this plant in this part of the land is due to its ability to endure harsh condition and it is also help full to prevent soil erosion. In this review article the main focus is on the chemical composition and therapeutic potential as well as pharmacologically explored potential of Acacia tortilis and its importance in arid and sub-arid part of the world to fulfill the requirement of local population and animals. Keywords: Arid, Acacia tortilis, Soil erosion, Reforestation.

We present a dip pen nanolithography study of various hydrophilic ink/surface systems with application in the field of biosensors and novel nano-materials. The inking process was investigated by studying a number of inks, such as Deoxyribonucleic acid (DNA), Bovine serum albumin (BSA), Streptavidin, 16-mercaptohexadecanoic acid (MHA) and a 20 nm nanosphere (NS) polystyrene solution onto a range of substrates, namely glass, silicon, gold and tetrahedral amorphous carbon (taC). In the majority of cases, this resulted in patterns with sub-100 nm line widths and dot diameters. Importantly, contact angle measurements in the microl range showed a decrease of contact angle with drop volume, interpreted as a line tension effect. The significance of this to the nanoscale wetting behaviour is discussed. The effect of dwell time and writing speed indicates that the inking process is not solely defined by surface diffusion but also influenced by the ink dissolution rate from the tip.

This article reports the use of dip pen nanolithography (DPN) for the study of adsorption of bovine serum albumin (BSA) proteins on amorphous carbon surfaces; tetrahedral amorphous carbon (t-aC) and silicon doped hydrogenated amorphous carbon (a-C:H:Si). Contact angle study shows that the BSA proteins reduce the contact angle on both carbon materials. We also noticed that the drop volume dependence is consistent with a negative line tension, i.e. due to an attractive protein/surface interaction. The DPN technique was used to write short-spaced (100nm) BSA line patterns on both samples. We found a line merging effect, stronger in the case of the a-C:H:Si material. We discuss possible contributions from tip blunting, scratching, cross-talk between lever torsion and bending and nano-shaving of the patterns. We conclude that the observed effect is caused in large measure by the diffusion of BSA proteins on the amorphous carbon surfaces. This interpretation of the result is consistent with the contact angle data and AFM force curve analysis indicating larger tip/surface adhesion and spreading for the a-C:H:Si material. We conclude by discussing the advantages and limitations of DPN lithography to study biomolecular adsorption in nanoscale wetting environments.

We present a comparative microscopic study on metallic templates prepared by nanosphere lithography. Scanning electron microscopy, low kV Energy dispersive X-ray spectroscopy, scanning ion microscopy, atomic force microscopy and confocal Raman spectroscopy were used to analyse the assembly of the nano-templates. Contact angle measurements allowed us to optimise the surface treatment of the Si substrate to obtain maximal spreading and regularity of the nanosphere arrays. After metal deposition and toluene nanosphere removal, we found the expected interstitial triangular structures, originating from the 2D single layer hexagonal sphere array. We also detected a number of other features such as rings, circles, cups and lines which were found to be generally positioned below the nanospheres. A review of proposed mechanisms and the various analysis performed here indicate that some of these features are partly polymeric and partly caused by residual material leaching out of the nanospheres at various stages of the process.

Arrays of carbon nanoflake spherules (CNSs) have been grown on the copper substrate by the microwave plasma assisted chemical vapour deposition method. Uniform sized CNSs of diameters of 700-950 nm have been produced. The CNSs are free from any other carbon nano-structures. The growth of CNSs has been found to be strongly affected by the undulating surface (crest-trough morphology) of the substrate with preferential growth along the direction of crests. Micro-Raman spectroscopic analysis reveals highly active surface of the graphitic edges of as-grown CNSs. A possible growth mechanism has been proposed which could be used for a large yield of arrays of the CNSs. The field-emission measurements show potential applications of the CNSs in the vacuum electronics devices with a low turn-on field of 7.4 V/mu m. (C) 2009 Elsevier B.V. All rights reserved.