Performance Analysis of 6T SRAM and ONOFIC Cells

Background: As the Technology node scales down to deep sub-micron regime, the design of static random-access memory (SRAM) cell becomes a critical issue because of increased leakage current components. These leakage current components prevent to design a low power processor as large of the processor power is consumed by the memory part. Objective: In this paper, a SRAM cell is designed based on ON/OFF logic (ONOFIC) approach. Static noise margin (SNM) of the cell for the different states are calculated and evaluated by using butterfly as well as noise (N) curves with the help of Cadence tools at 45 nm technology node. Methods: ONOFIC approach helps to reduce the leakage current components which makes a low power memory cell. A performance comparison is made between the conventional six-transistor (6T) SRAM cell and memory cell using ONOFIC approach. Results: Low value of power delay product (PDP) is the outcome of ONOFIC approach as compared to conventional cell. ONOFIC approach decreases PDP by 99.99% in case of hold state. Conclusions: ONOFIC approach improves the different performance metrics for the different states of the SRAM cell.

Hydrothermal Synthesis and Photocatalytic Performance of Barium Carbonate/tin Dioxide Nanoparticles

Background: Crystal violet dye is stable and difficult to be biodegraded owing to the existence of the multiple aromatic rings of the crystal violet molecules. Removing crystal violet dye from the wastewater is a major challenge. Objective: The aim of the research is to synthesize barium carbonate/tin dioxide nanoparticles and investigate the photocatalytic performance for the degradation of crystal violet. Methods: Barium carbonate/tin dioxide nanoparticles were synthesized via a facile hydrothermal route without any surfactants. The crystal structure, micro-morphology, size and optical performance of the barium carbonate/tin dioxide nanoparticles were investigated by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and solid ultraviolet-visible diffuse reflectance spectrum. Results : The size of the barium carbonate/tin dioxide nanoparticles is 20 nm to 200 nm with the band gap of 3.71 eV. The photocatalytic activity of the barium carbonate/tin dioxide nanoparticles was measured by the photocatalytic degradation of crystal violet. The crystal violet degradation efficiency reaches 92.1% with the ultraviolet-visible irradiation time of 8 h using 10 mg barium carbonate/tin dioxide nanoparticles. The crystal violet degradation ratio increases to 96.1% when the dosage of the barium carbonate/tin dioxide nanoparticles increases to 20 mg/10 mL crystal violet dye solution. Active species capture photocatalytic experiments showed that the holes, hydroxyl radicals and superoxide ion radicals are the main active species. Reusability experiments displayed that the barium carbonate/tin dioxide nanoparticles are stable for the crystal violet dye degradation. Conclusion: The barium carbonate/tin dioxide nanoparticles show good photocatalytic performance toward crystal violet under ultraviolet light irradiation.

Facile One-step Preparation of Mesoporous Siliceous phophsomolybdic acid for Proton Exchange Membrane

Background: Proton exchange membrane is art of PEM fuel cells, developing active materials with robust structure and high proton conductivity has attained huge attention in recent decade amongst researchers. Aims/objectives: Here we have developed a novel approach to prepare a siliceous mesoporous heteropoly acid with high stability in polar media and high proton conductivity to be utilized as proton exchange membrane. Methods: A highly stable mesoporous siliceous phosphomolybdic acid has been synthesized via a simple self-assembly between phosphomolybdic acid (PMA), the polymeric surfactant, and the silica precursor stabilized by KCl molecules as a proton conducting material for proton exchange membrane application. Results: As prepared siliceous mesoporous phosphomolybdic acids (mPMA-Si) show a high surface area with a highly crystalline structure, however the crystallinity reduced by increasing the silica content. Further analysis proved the Keggin structure remain intact in final materials. mPMA-8 Si shows the highest performance among all the materials studied with proton conductivity of 0.263 S.cm-1 at 70 oC. Conclusion: As prepared mPMA-xSi has shown a very high proton conductivity in a range of temperatures which make them a promising material for proton exchange membrane.

Plasmonic Properties of Al2O3 Nanoshell with a Metallic Core

Background: Al is the promising candidate for the deep UV and longer wavelength range plasmonic applications. But it is difficult to have the pure Aluminium nanostructure as it is easily oxidized forming a thin layer of Al2O3. In this paper we have evaluated the field enhancement of oxide layer on metallic shell (Al-Al2O3 and Au- Al2O3) for single and dimer core-shell configuration and shown potential of oxide layer in SERS. Methods: The Finite Difference Time Domain (FDTD) has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3 and Au- Al2O3 nanostructure. Results: The results exhibit the tunable plasmon resonance on varying the inner and outer radii of the Al2O3 shell. A redshift and decrease in enhancement were observed as shell thickness increases whereas on increasing the core size the enhancement gets increased in the case of Au-Al2O3 and gets a decrease in Al-Al2O3 due to quadrupole contribution. But on comparing the Au-Al2O3 with Al-Al2O3 for the same particle size, Al-Al2O3 shows larger enhancement because Au has to compete with its inter band transition. Conclusion: By optimizing the thickness of the shell and core size, it can be concluded that an ultrathin shell of Al2O3 can give higher enhancement. With Al as a core metal the enhancement increases as compared to Au-Al2O3. Since a single Al-Al2O3 nanoshell has shown a huge enhancement we have considered the multimer configuration of two identical nanoshell. Due to coupling between two nanoshell a huge increase in enhancement factor ~1012 was observed for Al-Al2O3 dimer nanoshell in the UV region.

Structural and Impedance Analysis of 0.7Pb(Mg1/3Nb2/3)O3- 0.3PbTiO3 Ceramic

Background: Since (1-x)[Pb(Mg1/3Nb2/3)O3]-(x)PbTiO3 (PMN-PT) ceramic has high dielectric constant and piezoelectric coefficient, it has been widely investigated for profound applications in electro-optical devices, sensors, multilayer capacitors and actuators. Objectives: The aim is to study the structural and electrical properties of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) ceramic to understand the biphasic structural nature using Rietveld Refinement. Also, it characterises on the basis of electrical properties such as impedance and modulus to understand the relaxation process, type of conduction process as well as the role of grain and grain boundary resistance in the material. Methods: 0.7PMN-0.3PT is synthesised by mixed oxide method using PbO, MgO, Nb2O5 and TiO2 as precursor materials. Results: The XRD data reveals the biphasic structure of tetragonal phase with the space group of P4mm and monoclinic phase with the space group of Pm. The complex impedance analysis clearly represents the effect of grain on the overall resistance and departs from normal Debye type behaviour. Also, the resistance is found to decrease with temperature, thereby confirming the semiconducting nature of the sample. The presence of long as well as short-range mobility of charge carriers is confirmed from the modulus and impedance analysis. The influence of long-range motion is observed at high temperature and of short-range motion at low temperatures. Conclusion: XRD analysis confirmed the biphasic structure of M+T phase. The frequency-dependent modulus and impedance spectroscopy show the presence of a relaxation effect in the ceramic which is found to increase with temperature. The Nyquist plot shows that the resistance is decreased with temperature, thereby confirming the NTCR behaviour in the studied sample.

Assessing the Grip of Solar Energy Systems on Environmental Sustainability-A Review

: A sustainable energy production system fulfills its goal while being environmentally, socially, and technically sound. The intermittent availability and viability of renewable energy makes this vision a gradual and long-suffering process. In the rapid result-oriented economy, concerns regarding the environment are treated with desperate solutions that may add fuel to the fire. Although substantial research has been going on in the development of emerging technologies and refinement of established systems, we need to be reminded of the larger goal in mind: a benign and sustainable environment. Closing a door on a problem and not opening several new ones is what we must yearn to achieve. Renewable energy systems and their utility may unintentionally harm a different subset of the ecosystem. Solar energy systems are a more recent candidate with a high annual growth rate and thus, are still in the nascent stage to realise the bruised potential of the technology. By 2050, 60 million tons of solar waste will be produced if it is not resolved efficiently. To achieve environmental sustainability, it is imperative to work towards recycling redundant systems, establishing producer responsibility, fulfilling social needs and optimising future technology. By integrating aspects of the research on solar energy systems, their environmental risks, and their potential to create a sustainable ecosystem, this review article attempts to cater to environmental decision making and direct the eventual research and analysis towards their original unified objective.

The Challenges of Biomedical Waste Management During the Ongoing Coronavirus Disease-19 (COVID-19) Pandemic: The Current Scenario

: The novel Coronavirus (SARS-CoV-2) that has emerged and spread throughout the world causing CoV disease-19 (COVID-19) has since its discovery affected not only humans and animals but also the environment. Because of the highly infectious nature of the virus, and the respiratory aerosol transmission route, face masks and personal protective equipment have become mandatory for public and healthcare workers, respectively. Also, the complex nature of the pathogenicity of the virus, wherein, it has been associated with mild, moderate, and severe life-threatening infections, has warranted increased laboratory testing and placing the infected people in isolation and under constant observation in quarantine centers or at dedicated hospitals. Some infected people, who are generally healthy, and do not show symptoms have been placed in home quarantines. At this juncture, there has been increased amount of biomedical waste (BMW), and infectious general waste along with plastic disposable recyclable and non-recyclable waste. The increased BMW along with the potentially hazardous plastic waste collection, segregation, transport, and disposal has assumed increased significance during the ongoing pandemic. Therefore, this review attempts to investigate the current scenario of BMW management and strategies to minimize BMW and prevent potential environmental pollution.