நானோ அறிவியல் இதழ்: தற்போதைய ஆராய்ச்சி

In this work poly (3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) dispersed in solvent (5wt.% Dimethyl sulfoxide DMSO & 0.1wt.% Triton X-100) has been studied in pure form and when functionallized with TiO₂ nanoparticles. A preliminary characterization of bare PEDOT:PSS and romarchite TiO₂ nanoparticles synthesized by hydrolysis were firstly carried out. PEDOT:PSS was deposited on n(FZ)-Si by spin coating method. The influence of a piranha pre-treatment on the Si surface has been evaluated in this work, as well as the effects due to the presence of TiO₂ nanoparticles in the polymer. After achieving good adhesion and passivation of Si surface, the heterostructure has been characterized systematically by means of Raman spectroscopy using a He-Cd (λ = 325 nm) laser as excitation source, atomic force microscopy (AFM), scanning electron microscopy (SEM) and photoluminescence (PL) spectra, and PL image. Spatial homogeneity of the film composition on surface has been achieved. Uniform defect distribution and presence of charged defects, material quality and vibrational structure have been studied. PEDOT:PSS thin film was obtained through solution process which involves adding a solvent additive and/or conducting post treatment at low temperatures. The film was obtained by static spin coating method on a n-type silicon substrate, followed by annealing of the film at 120^oC for 10-15 min. The achieved PEDOT:PSS layer thickness was around to be ~100 nm with the average surface roughness of 3:5±0:5 nm measured by AFM. Charge carrier lifetime measured by PL-machine was found out to be between 264-375 µs. By four probe measurements, the sheet resistance was found out to be 338 â?¦/sq.

The number of cars continues to increase due to the worldwide economic growth. This gives an impact not only on the condition of the roads, but also on the accumulation of tire waste. Research on improving the quality of road asphalt by utilizing crumb rubber (CR) from car tires has been carried out by many researchers and has given positive results. However, each researcher suggests a different composition of CR to get the best quality of asphalt rubber. This study provides an overview and prediction regarding the efficiency of Nano Asphalt Rubber (NAR) production by using Central Composite Method (CCM) and Response Surface Method (RSM). This work can give an idea to the researcher or decision maker of how much CR should be added in asphalt mixture to get the optimum result, especially when using Asbuton as the bitumen source. The results of the optimization using the CCM and RSM in Minitab® i.e. regression equations, contour plot and surface plots, can be used to see the Yield range of AR production. The NAR production is carried out by extracting the Asbuton (in-situ) with ultrasonication technique and mixing it with CR according to a 5-factors full factorial design. The result shows that the highest NAR Yield in the optimization process can reach 99.9%.

Energy storage capacity, conversion efficiency with clean power to the environment makes PEC photovoltaic cell to seek out potential applications within the field of energy. Suitable bandgap and high stability make CdSe (Cadmium Selenide), a promising material for photovoltaic cell applications. Also, the performance of CdSe based devices is influenced by doping with suitable material. In our present work beam (EB) evaporation method was employed to deposit CdSe and Indium doped CdSe (with In concentration of 25, 50 and 75%) thin films at different substrate temperatures and therefore the films were optimized for the preparation of (Photo electrochemical) PEC solar cells. The EDX analysis shows the rise within the percentage of indium with the rise within the concentration of doping and therefore the X-ray analysis shows the shifting within the peak position which confirms the incorporation of indium. The grain sizes were found to be within the range of 20-24 nm and it's found to decrease with a rise in concentration. The calculated energy gap value decreased with increase in concentration. PEC photovoltaic cell is fabricated using CdSe: In films prepared by EB technique with a thickness of 400 nm and substrate temperature of 100°C. The I-V studies performed under the illumination of 100 mW/cm2 and it's found that the 25% of indium in CdSe showed an efficiency of two .66% and fill factor of 0.41.

There is an incredible interest within the physical and chemicalproperties of nanocrystalline thin films on the idea of quantum confinement effects. Tuning of the band gap by changing the parti-cle size and consequent band edge luminescence over the entire visible range has been utilized in optoelectronic devices, biolabeling etc. Thin films of II–VI semiconductors are of considerable interest due to their excellent optical properties within the visible range. Metal selenide thin films offer a variety of optical band gap energies suitable for various optical and optoelectronic applications. CdSe may be a widely used semiconductor whose band gap (Eg= 1.7 eV) lies within the solar power spectrum. it's one among the prom-ising semiconducting materials that are studied for application in solar cells, thin film transistors, gamma-ray detectors, photodetection and optoelectronic applications. CdSe can exist in either zincblende (cubic) or wurtzite (hexagonal) modification in solid state.

Doped semiconductor nanoparticles are studied exten-sively due to their excellent luminescence properties. Dop-ing may be a widely used method to tailor the electrical and optical properties of semiconductors. Major attention has been given in recent years to the investigation of electrical and optical proper-ties of doped CdSe thin films so as to enhance the performance of the devices and also to find new applications. Various methods have been reported to organize In doped CdSe thin films.

Clean water as basic human need isn't available to 1.4 -1.8 billion people round the world. it's essential to DC research trends toward sustainable water and wastewater treatment technologies which will solve the prevailing industrial and environmental issues, especially when it involves solutions which will be successfully commercialized on the worldwide scale. Membrane applications are the foremost effective and sustainable methods of addressing environmental problems in treating water and wastewater to satisfy or exceed stringent environmental standards. Nevertheless, membrane fouling is one among the first operational concerns that's currently hindering its widespread application. Her major research focus is to optimize synthesis of biomimetic membranes designed with antifouling, and selective permeation which will pave the way for the assembly of unpolluted water.

Sustainable energy is that the key solution for addressing major concerns about the longer term like global climate change, environmental protection, and balanced growth of the economy and society. The past 20 years have witnessed advancement in economic development in many nations. However, the rapid economic process , industrial advancement, energy shortage, deterioration of the environment and increasing demands of growing populations pose an enormous threat for future generations. for several years, economic development has been the key focus of the many policy makers in sustainable development until the inception of the Kyoto protocol agreement in 1997, which incorporates environmental quality as an important variable for sustainable development. With global energy consumption and electricity demands expected to double within the next twenty-five years, major opportunities for innovation in how energy is produced, stored, transmitted and used have begun to open up. especially, there's an enormous interest in sustainable energy technologies capable of improving efficiency and reducing the worldwide carbon footprint.

The development of sustainable energy is, however, restricted by various factors, like the supply of natural resources thanks to regional differences, sensitivity to the environmental impacts of fossil-fuel based energy, increasing water scarcity, and differing economic policies. Development of an approach to sustainable energy that addresses environmental concerns, greenhouse emission emission, cost, availability of resources, and social impact may be a huge challenge. The key focus for attaining energy sustainability is to scale back and slowly replace power generation by fossil fuels with renewable energy sources. Though some aspects of this sustainable approach are being adopted, there are others yet to be translated at a billboard scale. as an example , major concerns about CO2 (CO2) emissions in traditional fossil fuel-based power generation has paved the way for several sustainable energy sources like wind and solar, alongside CO2 capture and sequestration technologies. aside from this, there's a growing recognition of technologies like cogeneration plants, where a mixture of techniques contributes to reduced water demand while generating energy, leading to effective water use to satisfy the demand. Water and energy are the 2 key aspects for sustainable development for the longer term. 

Microcracks can occur in carbon fiber composite materials thanks to high thermal stresses induced by the massive difference of the coefficient of thermal expansion between the polymer matrix and therefore the carbon fibers. These micro-cracks can severely degrade the mechanical strength and gas permeability of composites, posing a big challenge to the utilization of fiber composites in liquid fuel tanks of launch vehicles. The aim of the study was to develop a multi-scale toughening method to deal with the micro-cracking problem by incorporating hybrid nano-scale materials to reinforce the fracture toughness and to scale back the coefficient of thermal expansion of the polymer matrix. Nanomaterials like nano-silica, graphene and metal oxide were selected supported their thermal properties and toughening effect. Tensile and Single Edge Notch Bending (SENB) testing of the polymer and nanocomposites were administered to review their tensile properties and bulk fracture toughness respectively, while Double Cantilever Beam (DCB) testing was administered to work out the critical energy release rate (GIC values) of the fiber-polymer laminates. The results show that nano-silica improved the fracture toughness of the composites while metal oxide nanoparticles provided the simplest improvement in thermal conductivity, lastingness, and fracture toughness.

Introduction: Carbon fiber reinforced resin matrix composite materials (CFRC) are getting used within the aerospace industry as a way of reducing vehicle weight. CFRC has advantages in high strength-to-weight and high stiffness-to-weight ratios. For future heavy-lift launch vehicles and space exploration structures, advanced lightweight composites are going to be fully utilized so as to attenuate vehicle weight, and CFRC in space applications requires rigorous development to demonstrate robustness, durability, and high factors of safety. the longer term heavy-lift launch vehicles require extremely high propellant mass fractions to realize the designed performance. This drives the designers to include lightweight materials into as many structures as possible. Propellant fuel tanks account for an outsized proportion of the launch vehicles, both structural mass and geometric space. Approximately 60% of the dry mass of a launch vehicle is that the fuel and oxidizer tanks. The implementation of composite cryogenic propellant fuel tanks (cryotank) for future heavy-lift launch vehicles could greatly reduce the vehicle’s weight by replacing the identically sized cryo tanks constructed of metallic materials. United States’ Committee on Materials Needs and R&D Strategy for Future Military Aerospace Propulsion Systems reported that composites offer the potential for the best mass reduction of all of the materials for the tank. For the case of Delta IV heavy-lift launch vehicle, as shown, compared to Li-Al fuel tank, the load saving of upper stage composite cryo tanks was 43 and 26%, respectively. additionally, composite design could reduce fabrication costs. Delta II faring, Delta III faring, and interstage production data have shown that composite launch vehicle structures are less costly than metal ones. Graphite-epoxy composite cryogenic tank development began at Boeing (then McDonnell Douglas) in 1987 and continues today, primarily for reusable launch vehicles (RLV) and heavy-lift vehicles. The cryogenic tanks are the dominating components of the vehicle structure. to realize a weight reduction of the next-generation launch vehicles, carbon fiber reinforced polymeric based composites are being explored for the cryogenic liquid fuel tank. A composite cryo tank structure can save 30% by weight than lithium aluminum alloy.

I am pleased to introduce International Journal of Nanosciences: Current Research (JNCR) which is an open access electronic journal aiming to provide an online compendium for Nano science Research & Technology. The interdisciplinary coverage of the Journal includes all the basic and applied research of Nano scale sciences with innovative Nanotechnology applications towards science, engineering and technology. We have been started in year 2016 Journal of Nanosciences: Current Research (ISSN: 2572-0813) is growing continuously. It is our pleasure to announce that during year 2019, all issues of volume 12 were published online on time and the print issues were also brought out and dispatched within 30 days of publishing the issue online.

All published articles of this journal are included in the indexing and abstracting coverage of Index Copernicus, Google Scholar, Sherpa Romeo, Academic Journals Database, Open J Gate, Genamics Journal Seek, Academic Keys, ResearchBible, Directory of Open Access Journals, VieSearch, China National Knowledge Infrastructure (CNKI), Electronic Journals Library, RefSeek, Directory of Research Journal Indexing (DRJI), EBSCO A-Z, OCLC- WorldCat, SWB online catalog, Publons, Advanced Science Index, Secret Search Engine Labs.

During the calendar year 2019, Journal of Nanosciences: Current Research received a total of 20 papers, out of which 10 articles were rejected in the preliminary screening due to plagiarism or being out of the format and peer review process. During 2019 around 10 articles were subjected for publication after they are accepted in the peer review process. In the 2 issues of Volume 4 published during the year 2019, a total of 10 articles were published (at an average of 5 articles per issue of which, articles were published from authors all around the world. A total of 25 research scientists from all over the world reviewed the 10 articles published in volume 4. Average publication period of an article was further reduced to 14-21 days.

During the calendar year 2019, a total of three Editors, ten Reviewers joined the board of JNCR and contributed their valuable services towards contribution as well as publication of articles, and their valuable reviewer comments will beneficial to publish quality of article in the Journal.

I take this opportunity to acknowledge the contribution of Editor-in-chief and Associate Editor during the final editing of articles published and bringing out issues of JNCR in time. I would also like to express my gratitude to all the authors, reviewers, the publisher, language editor, honorary editors, the scientific advisory and the editorial board of JNCR, the office bearers for their support in bringing out the new volume (Volume 5, Issue 3) of JNCR for the calendar year 2020 and look forward to their unrelenting support further to release more issues for Journal of Nanosciences: Current Research (JNCR) in scheduled time.

Ribonucleic acid (RNA) is of great importance because it ranges from laboratory tests, to diagnoses of viral, bacterial and parasitic diseases, inherited disorders and tumors, and even basic research. To provide reliable results, molecular biology techniques are used to extract it from prokaryotic or eukaryotic cells, but it is necessary to obtain pure and intact RNA biomolecules. Therefore, purifying the RNA is a critical step to obtain good quality RNA molecules (pure and intact). For these reasons, this thesis project will develop mesoporous silicas of the SBA-15 type functionalized with amino and mercaptan, as adsorbent materials for RNA purification. These functionalized mesoporous silicas that must have adequate textural properties (pore diameter in the mesoporous range of 7 nm and high surface area of up to 950 m2 / g) will allow the adsorption of RNA biomolecules on their surface through functional groups. Furthermore, these adsorbent materials are expected to purify RNA molecules with uniform size. In order to find an explanation for the behavior of adsorbent materials in RNA purification, they will be characterized by low angle X-ray Diffraction (SAXRD, Small-Angle X-Ray Diffraction), Raman spectroscopy, thermal analysis and gel electrophoresis.