Growth of Oriented Au Nanostructures: Role of Oxide at the Interface

We report on the formation of oriented gold nano structures on Si(100) substrate by annealing procedures in low vacuum (\approx10-2 mbar) and at high temperature (\approx 975^{\circ} C). Various thicknesses of gold films have been deposited with SiOx (using high vacuum thermal evaporation) and without SiOx (using molecular beam epitaxy) at the interface on Si(100). Electron microscopy measurements were performed to determine the morphology, orientation of the structures and the nature of oxide layer. Interfacial oxide layer, low vacuum and high temperature annealing conditions are found to be necessary to grow oriented gold structures. These gold structures can be transferred by simple scratching method.Comment: 13 pages, 3 figures, Accepted in J. Appl. Phy

Journey of Research Practice

Welcome to the inaugural issue of the Journal of Research Practice (JRP). This journal has resulted from a widely shared interest that researchers in different disciplines and professional fields should communicate with each other freely and remain open to learn from each other’s individual journey of research.The title of this journal may look surprising to some readers. There may even be a legitimate doubt as to whether the journal would take-off at all, the title being so broad and unspecific. On the contrary, to be more optimistic, the journal could meet a long-felt need, i.e., that of bringing researchers, and various forms of organised inquiry, into fruitful connections with each other, without the restrictions imposed by formal disciplinary boundaries.Research and researchers have been the focus of many discussions in the past. These discussions have proliferated following different threads. There is a logical (and philosophical) thread that seeks to explicate the logic of research and the structure of scientific inquiry, seeking out the rules and methods deployed by researchers in arriving at justifiable results. It also delves into the ideology of scientific research. There is a sociological thread that seeks to understand research communities as social entities and knowledge as a product of social interaction among human beings. There is an institutional or political-economic thread that seeks to understand the workings of regional or national research systems--complete with their councils, funding, and power play. Likewise, there are other threads too, such as research as a space of struggle and resistance, research as a practice of freedom and self-transcendence, etc. There is something to be gained by bringing these threads together, in the hands of researchers themselves, no matter what disciplines or fields they might individually pursue

Studies on the In-Situ Formation of AI2O3 - SiC Ceramic Matrix Composite from Tata Steel Colliery over Burden

Raw materials suitable for the production of in-situ ceramic matrix composites (CMC) are scarce. In the present investigation, colliery over burden has been identified as a promising feedstock for the preparation of Al,O3-SiC CMC. Colliery minestones from Tata Steel colliery has been assessed chemically and found to contain alumina, silica and carbon. After preliminary processing of minestones, high temperature synthesis has been carried out in the laboratory-scale as well as relatively larger scale to produce CMC. The results of the investigation have shown that substantial amount of silicon carbide whiskers and particulates could be produced in the alumina matrix. Bench scale as well as larger scale production trials have been found to be successful in terms of yield of SiC and its quality. Additionally, in-situ AI,O3-SiC CMC has been found to contain carbon over and above required for the formation of SiC. Thus Al,03-SiC-C CMC has been gainfully utilised in the preparation of aluminium based metal matrix composite with distinct advantages of higher strength combined with improved ductility

Effect of simultaneous application of field and pressure on magnetic transitions in La0.5{_{0.5}}Ca0.5{_{0.5}}MnO3{_{3}}

We study combined effect of hydrostatic pressure and magnetic field on the magnetization of La${_{0.5}}$Ca${_{0.5}}$MnO${_{3}}$. We do not observe any significant effect of pressure on the paramagnetic to ferromagnetic transition. However, pressure asymmetrically affects the thermal hysteresis across the ferro-antiferromagnetic first-order transition, which has strong field dependence. Though the supercooling (T*) and superheating (T**) temperatures decrease and the value of magnetization at 5K (M$_{5K}$) increases with pressure, T* and M$_{5K}$ shows abrupt changes in tiny pressure of 0.68kbar. These anomalies enhance with field. In 7Tesla field, transition to antiferromagnetic phase disappears in 0.68kbar and M$_{5K}$ show significant increase. Thereafter, increase in pressure up to $\sim$10kbar has no noticeable effect on the magnetization

Effect of silver nanoparticles on growth of eukaryotic green algae

Silver nanoparticles, endowed with powerful antimicrobial property, are the most widely used nanomaterial in consumer products, with associated risk of their easy access to environment and freshwater ecosystems by surface runoff. Although toxic effects of nanosilver on bacterial, fungal and mammalian cells have been documented, its impact on algal growth remains unknown. Pithophora oedogonia and Chara vulgaris are predominant members of photosynthetic eukaryotic algae, which form major component of global aquatic ecosystem. Here we report for the first time that nanosilver has significant adverse effects on growth and morphology of these filamentous green algae in a dose-dependent manner. Exposure of algal thalli to increasing concentrations of silver nanoparticles resulted in progressive depletion in algal chlorophyll content, chromosome instability and mitotic disturbance, associated with morphological malformations in algal filaments. SEM micrographs revealed dramatic alterations in cell wall in nanoparticle-treated algae, characterized with cell wall rupture and degradation in Pithophora. Although these observations underscore severe deleterious effects of nanosilver on aquatic environment, the information can also be exploited as a bioengineering strategy to control unwanted and persistent growth of noxious algal weeds that clog the municipal water supply and water channels and produce fouling of water bodies

Effect of Helical Winding Angle on External Pressure based Buckling of Partially Filled Thin Composite Cylindrical Shells

Effect of helical winding angle on buckling load of thin composite tubes is investigated in this work.  Experiments are conducted on both empty and partially filled S2 glass tubes to estimate contribution of strength to the tubes by the filler material.  Chosen filler material mechanically simulates behavior of typical solid propellant used in aerospace application.   FE analysis with non-linear effect correlates well with the experimental data.  Three series of experiments are conducted to quantify effect of helical winding angle and increase in volumetric loading fraction(VLF).  Results confirm appreciable improvement in strength of filled tubes for higher VLF.  For the chosen pattern of winding, lower winding angle provides more strength to the tubes against external pressure buckling.  &nbsp

Heat and mass transfer on MHD flow through a porous medium over a stretching surface with heat source

An attempt has been made to study the heat and mass transfer effect on the flow over a stretching sheet in the presence of a heat source. The novelty of the present study is to consider the span wise variation of magnetic field strength, heat source and heat flux. It is also considered the effect of viscous dissipation. The method of solution involves similarity transformation which leads to an exact solution of velocity field. The coupled non-linear and non homogeneous heat equation has been solved by applying Kummer’s function. The non-homogeneity of the heat equation is contributed by the consideration of viscous dissipative energy. KYEWORDS: Heat source, Viscous dissipation, Porous medium, Kummer’s function

Immaculateness and Research Practice

Notions of purity, perfection, or immaculateness have powered our imagination over the ages. Various images of perfection have held sway in their hallowed times, providing secure streams for channelling human energy. Unfortunately, with the unfolding of the human drama on the world stage, all the images of perfection have suffered damage, epoch on epoch. Different responses have emerged to attempt a restoration. Revival of some of the old images is one such response. Production of new images to serve as worthwhile anchors of value and meaning is another common response. For reasons possibly known only to philosophers and historians, the enterprise called modern science has got thickly embroiled in this civilisational process--first, as the culprit behind the decline of some of the established images, then as the producer of new images, and now, perhaps, as a constant reminder of the perpetual lack of purity and immaculateness in all things human