Nanoscience & Nanotechnology-Asia - Volume 13, Issue 1, 2023

This paper analyses the performance of 5 nm gate length gate engineered oxide stack silicon on insulator (SOI) fin field-effect transistor (OS-Fin-FET) for the first time. The high dielectric (High-K) value of the material-based gate oxide stack structure increases both the analog and the radio frequency (RF) performance of the Fin-FET device when compared to standard single gate oxide material structures. The work function of the engineered gate structure further helps in advancing the performance of the device in terms of on current (Ion), off current (Ioff) and the ratio of Ion/Ioff. The proposed OS-FinFET device improves on current (Ion) of the device by 12% in comparison to the high-K dielectric gate oxidebased FinFET device. Simulation of the device is further extended to study different electrical characteristics of the proposed device under other biasing conditions, to estimate enhanced analog and RF performance where the device is highly suitable for low power and high-speed applications. Overall, the proposed device shows improvement in existing architectures of the devices. Technology computer-aided design (TCAD) tool is used to perform entire simulations of the proposed device with 5 nm gate length. Aim: To enhance analog and RF performance of the Fin-FET device at 5 nm gate length. Background: Design of the sub-10 nm Fin-FET device undergoes charge shearing phenomena because of the minimum distance between source and drain. This problem is addressed by using High-K spacer over substrate but it leads to increase in the channel resistance and adverse short channel effects. A combination of different high-K dielectric materials can eliminate this performance. Hence most of the studies concentrated on spacer region and failed to consider channel region. This study tries to improve analog performance of the device using the approach of gate engineering with gate stack approach. Objective: The main objective of this study is to increase on current (Ion) of the device by implementing gate engineering approach, by choosing dual work function-based gate with oxide stack approach. The High-K dielectric material-based gate oxide reduces leakage current, decreases off current which will increase the ratio of Ion/Ioff. Methods: The dual work function gate material is taken with gate oxide stack approach by considering different High-K dielectric materials like HfO2, TiO2 with thin SiO2 layer as the interactive layer. Simulation of the device is carried out using TCAD Tool and results are compared with existing literature, to validate the results. Results: The proposed architecture of the Fin-FET device delivers excellent results in terms of on current and subthreshold characteristics compared to existing literature. The proposed device gives high on current of 0.027 A and current ratio of 1.08X104. Conclusion: A complete comparative analysis is carried out with existing literature on the proposed device, where the proposed device resulted in high performance. The proposed device improves 12% compared to existing literature, which is highly suitable for low power applications.

Background: Two-dimensional Williamson nanofluid flow with magnetic effects occurs through an extending surface immersed in a porous media. This includes the impact of the applied magnetic field, chemical reactions, variable thermal conductivity, and heat generation. Based on the above assumption, this study investigates a hydromagnetic Williamson nanofluid passed through a stretching surface embedded in a porous media that is being analysed by assuming the impact of thermal radiation and magnetic field on the flow properties. Methods: After using an appropriate similarity transformation, the governing equations with boundary conditions were converted into a dimensionless form. These derived ordinary differential equations are highly nonlinear partial differential equations that are solved numerically using the spectral local linearisation method. Results: An analysis and comparison of results with existing literature are reported here. Excellent agreement has been found between our results and those previously published. The impact of the magnetic field parameters, heat generation, variable thermal conductivity, and chemical reaction parameters on the velocity, thermal, and concentration profiles are inspected in graphical and tabular forms. Conclusion: The outcomes indicate that the velocity reduces with the increase in Williamson, porosity, and magnetic field parameters, whereas the concentration profile improves with these parameters. Entropy generation rate is also enhanced when the concentration difference parameter, Reynolds number, and Brinkman number are increased. Our results are extremely relevant and prove the same. A rise in the porosity parameter drops the velocity profiles but increases the temperature and concentration profiles. The entropy generation number is enhanced when the concentration difference parameter, Reynolds, and Brinkman numbers are increased.

Dendrimers are nanosized macromolecules with a hyperbranched globular shape that are commonly employed for drug delivery. They have shown to be both complex and valuable due to their high level of surface functioning, adaptability, and unique features. Furthermore, dendrimers have a wide range of applications in supramolecular chemistry, mainly in self-assembly processes. The potential of this macromolecule to construct a definite architectural design in terms of size, shape, branching length, density, and its well-defined molecular structure and segmented spherical construction has sparked a wide range of research on the interactions that occur between biological organisms. Dendrimers are "grown" from a central core in a repetitive divergent manufacturing process, with each succeeding step representing a new "generation" of the dendrimer. In comparison to linear polymers, dendrimers have more precisely controlled structures, globular in shape, and have a specific molecular weight rather than a range of molecular weights. The divergence in dendritic structure customization provides a one-of-a-kind framework for drug delivery to acute and chronic diseases. The development of efficient drug delivery systems based on dendrimers has attracted much interest in recent years. This review aims to discuss some important perspectives and recent patents regarding dendrimers.

Food is a basic need of every living being in the world. Food production and demand do not match well in many countries due to social, technical, and technological factors. Therefore, food industries need to be developed beyond their limits. The introduction of nanotechnology to the food industry can expand the capabilities in terms of food processing and preservation aspects directly. Furthermore, nanotechnology facilitates better thermal stability, better solubility, food security, preservation capabilities, and novel and high bioavailability foods. It is a nanometer-scale technology that operates with materials having a size range of 1-100 nanometers. This review focuses on the recent approaches to nanotechnology in the food industries. For instance, enhancement of bioavailability of food using nanoencapsulation, nano emulsification, and nanoprecipitation, nanomaterials in food packaging applications such as active packaging, improved packaging, smart packaging, antimicrobial properties of different nanomaterials, application of nanotechnology on food pathogen detection, safety issues, and future trends are the key components of this review. Recent studies and research have shown the positive results of nanotechnology and proven their importance and possibilities in contributing to the food sector. However, there are some safety concerns about nanotechnology-related applications. Therefore, lots of research are conducted on the potential risk of nanoparticles on essential organs such as the brain, liver, kidney, epididymis, testis, ovary, and uterus-like organs. Moreover, the safety issues of nanotechnology on human health, such as DNA damage, oxidative stress, cell shrinkage, cytoplasmic density increment, and apoptotic body appearance, have been reported due to some nanoparticles, including silver, titanium, and zinc oxide.

Background: Chrysin, a flavonoid, occurs naturally in plants and possesses many pharmacological actions, but there is a lack of suitable analytical methods for its estimation. Objective: To develop a simple analytical method and validate it for the estimation of Chrysin using reverse phase high-performance liquid chromatography (RP-HPLC). Methods: Isocratic elution was carried out in methanol and 0.1% v/v formic acid in a 70:30 ratio using a C-18 reverse-phase column. The flow rate was set to 1 mL min^-1 and the detection wavelength at 268 nm. As per ICH Q2 (R1) guidelines, the developed method was validated in terms of accuracy, precision, system suitability, and robustness. Results: The retention time of Chrysin was found at 10.269 min. In the concentration range of 2-10 μg/mL, the developed method was linear with a regression coefficient (R²) value of 0.998. The mean percentage recovery of Chrysin was found within 95-105% at all three levels, which confirms that the developed method was accurate. Moreover, the % RSD was found to be less than 2% confirming that the developed method was precise. The limit of detection and limit of quantification were found to be 0.071 and 0.217 μg/mL. Moreover, the validated method was robust with no significant changes in response to variation in flow rate, mobile phase composition, wavelength, and different lots of columns. Conclusion: It was concluded that the developed method has passed all validation tests and was successfully applied to estimate the presence of Chrysin in bulk as well as in pharmaceutical formulations.

Background: Quantum-dot Cellular Automata (QCA) is a new emerging nanotechnology that has been proven to be an improved alternative to complementary metal oxide semiconductor (CMOS) technology. It consists of a group of cells that can perform computational functions when combined and arranged in a particular manner. Objective: The Flip-Flops are widely affiliated with the circuits of logical and arithmetic unit structures that are used for the processors. Data (D) Flip-Flop is the most important and widely used Flip-Flop among all different types due to its better performance and efficiency. Hence, an efficient D Flip-Flop needs to be developed using QCA nanotechnology. Methods: This paper proposes a new design for D Flip-Flop in QCA nanotechnology. The proposed D Flip-Flop has 28 quantum cells and covers an area of 0.03 μm² . Furthermore, the paper presents a new design for a 3-bit Shift Register using the proposed D Flip-Flops in QCA nanotechnology keeping in mind the importance of the same in storing and transferring multiple bits of data. Results: The proposed D Flip-Flop and the 3-bit Shift Register are compared with the existing QCAbased designs. The proposed Shift Register has 100 quantum cells and covers an area of 0.11 μm² . Conclusion: The comparison concludes that the proposed D Flip-Flop and the 3-bit Shift Register have used a lesser number of QCA cells and covered smaller areas than the previous works. The proposed designs have been designed in a single layer without any crossover.

Introduction: Precipitated Silica has very high commercial significance in terms of ease of preparation, market volume, cost benefits and a wide range of industrial applications. The surface silanol groups of Precipitated Silica can be modified with reactive organic functional groups to achieve desired properties for specific applications, including catalysis. Objective: The objective of this study is to demonstrate sulfonic acid functionalized Precipitated Silica as a true heterogeneous catalyst in acetylation reaction, where the catalytic activity and desired product selectivity is a magnitude higher than industrial solid acid zeolite catalysts as well as similar catalysts reported in literature. Methods: A novel and cost-effective method for the functionalization of Precipitated Silica with sulfonic acid (-SO3H) is reported, where the silica nanoparticles are first functionalized in situ with a tetrasulfide organosilane, followed by oxidation of the tetrasulfide moiety to -SO3H groups, which are grafted to the surface silanol groups through covalent linkage. Results: CHNS analyses and XPS prove successful functionalization of -SO3H group onto the nano silica surface. The resultant material acts as a solid acid catalyst and shows exceptional activity in the acetylation of benzyl alcohol and >99% selectivity towards the desired product benzyl acetate. The resultant material can also be recycled and reused several times. Conclusion: The following factors make sulfonic acid functionalized Precipitated Silica a new generation of solid acid catalyst; (i) higher atom economy, (ii) recyclability and reusability, and (iii) significant cost benefits with respect to industrial catalysts.