http://hdl.handle.net/123456789/839 Sun, 14 Jun 2026 00:31:11 GMT 2026-06-14T00:31:11Z http://hdl.handle.net/123456789/2748 Title: Study of Synthesized Pure and Doped Iron Oxide Nanostructures for Magnetic Properties Authors: Dhillon, Gulshan Abstract: Nanotechnology has emerged intensively in recent years and has become one of the most imperative and exhilarating forefront fields in chemistry, physics, engineering, and biology. A particle having one or more dimensions of the order 100 nm or less is generally defined as a nanoparticle, and in nanotechnology, a particle is demarcated as a minor object that behaves as a complete unit in terms of its conveyance and properties. Nanoparticles exhibit several sizes related properties that vary significantly from those observed in bulk materials. The attention grabbing properties of nanoparticles are mainly owing to the large surface area to volume ratio, and quantum confinement effects observed in nanomaterials. Nanoparticles are found in different dimensions like 0-D, 1-D, 2-D, 3-D depending upon the number of confined directions of the electrons Thu, 01 Jul 2021 00:00:00 GMT http://hdl.handle.net/123456789/2748 2021-07-01T00:00:00Z http://hdl.handle.net/123456789/2735 Title: FLUIDIZATION CHARACTERISTICS OF PINE NEEDLES IN FLUIDIZED BED Authors: Vishal, Sharma Abstract: ABSTRACT Energy dispersion has directly influenced the prosperity and well-being of the nation. The era of urbanization and industrialization desperately deteriorating the World's natural energy sources, which contributed to their maximum capacity for energy generation. It resulted in drastic environmental conditions and drying out limited conventional energy sources. This instigates the worldwide consideration to explore the alternative sources of energy that have provided renewable and sustainable options. Biomass is highlighted as one of the ecological and inexhaustible sources undertaken to meet the growing energy demand. Modern biomass utilization technologies create opportunities to access energy from biomass (forest waste, agricultural waste, organic matter, etc.), which are not fully explored for energy generation. Moreover, coniferous forest residue, such as pine needles, has enormous potential in Himalayan territories, has been providing the best options for industrial development and promoting urbanization. It could play a significant role in energy supply. Additionally, the generation of energy from coniferous forest waste can offer the best options to the disposal of pine needles in these regions. The identification of appropriate techniques for utilizing this tremendous source can be profited environmentally and economically. Fluidized bed combustion technique can provide the best-operating environmental conditions for combustion of any type of fuels in air rich conditions, resulting in controllable emission of carbon dioxide (CO2). The present study is focused on exploring and identifying the energy potential accessible in the excess amount of pine needles in the Himalayan territories and to examine the fluidization characteristics in the lab-scale fluidized bed. The present study is investigated in three significant steps: 1) The estimation of the pine needles potential and study its physicochemical properties through ultimate analysis, Thu, 01 Oct 2020 00:00:00 GMT http://hdl.handle.net/123456789/2735 2020-10-01T00:00:00Z http://hdl.handle.net/123456789/2717 Title: PREPARATION AND CHARACTERIZATION OF NORMAL AND REVERSE MODE POLYMER DISPERSED LIQUID CRYSTALS Authors: SHARMA, VANDNA Abstract: Polymer dispersed liquid crystals (PDLCs) have become an area of interdisciplinary research and developing their great scientific attention in this field. In PDLCs, liquid crystal (LC) is trapped as drops embedded within a polymeric matrix and LC molecules within droplets are randomly aligned parallel to the substrate and scattered light in OFF state. However, in reverse mode PDLC, LC is vertically aligned (VA) initially and transparent in OFF state. Thus, research work was focused to prepare normal and reverse mode PDLCs and studied their droplet morphology, electro-optic (EO) characteristics, threshold and operating voltages, contrast ratio (CR), response time and absorption behaviour as well as interdependency among all these parameters. Initially, Introduction of LC to PDLCs along with process cum formation of normal and reverse modes was studied and reviewed the advancements in the field extensively. Further, normal mode PDLCs for conventional (pure) and with the doping of silica nanoparticles (NPs) and multiwall carbon nano tubes (CNTs) were prepared and investigated in detail. Results have shown that NPs and multiwall CNTs in PDLC readily controlled the molecular orientation and dynamics of LC in droplets with reduced value of threshold electric field in addition to higher contrast. Further, work was continued with the effect of doping of azo orange dichroic dye having varied concentrations (0.0625%-1.0% of LC) in PDLCs were prepared and characterized. Experimental results showed that controlled amount of azo orange dichroic dye reduce the scattering with the alignment of the LC molecules along the director and showed enhanced EO characteristics as compared to conventional normal mode PDLCs. Moreover, the effect of NPs and dye in reverse mode PDLCs was also observed. Consequently, in reverse mode PDLCs, the POM study confirmed the development of VA of LC within the LC droplets. Droplet configuration varies with applied voltage and showed the scattering state with radially planar type textures. Doping of NPs, dye and (NPs + dye) reduced the threshold and operating voltages significantly, found 3.89 V & 12.7 V, 4.92 V & 13.3 V as well as 3.51 V & 11.3 V, respectively for NPs, dye and (NPs + dye) doped as compared with 6.09 V & 15.05 V required for conventional (without doping) reverse mode PDLC. In addition, CR was also found improved 25.18, 26.4 and 33.78 for NPs, dye and (NPs + dye) doped, respectively, compared with 14.5 for conventional reverse mode PDLC. Thus, the augmented performance of doped normal and reverse mode PDLCs with improved CR and low driving voltages will be of great interest of energy efficient display devic Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/123456789/2717 2020-01-01T00:00:00Z http://hdl.handle.net/123456789/858 Title: Preparation and characterization of nano particles induced vertically aligned liquid crystal Authors: ., Chinky Abstract: With the increasing demand of liquid crystal displays (LCDs) over past few decades, the need of vertically aligned liquid crystal (VALC) display devices have been increased tremendously because VALC displays possess much improved morphological and electro-optical (E-O) performance which is the prior demand of users. Consequently, several researchers have studied nano-particles (NPs) doped VALC devices and reported enhanced E-O characteristics of LCDs with the reduced threshold and operating fields. However, the manufacturing processes of these VALC devices are still complicated and more time consuming due to involvement of different process steps like polyimide coating, high temperature baking and rubbing etc. Fri, 26 Jul 2019 00:00:00 GMT http://hdl.handle.net/123456789/858 2019-07-26T00:00:00Z