PES University

Maruthi N., Faisal M., Raghavendra N.

Electromagnetic interference (EMI) has been identified as one of the ever increasing unfortunate byproducts due to the exhaustive implementation of numerous electronic devices and systems. In order to control EMI and associated problems, there is increasing need for efficient shielding materials. It is well-known that single composition materials cannot provide the required EMI shielding efficiency, various composite materials with different combination of dissimilar materials have been fabricated. Among the various class of composite materials developed as EMI shielding materials, conducting polymer based composites have gained special recognition owing to their unique properties such as light-weight, processability, environmental stability, long life, durable, and less corrosive with tunability. This review paper gives a comprehensive survey on the recent works on conducting polymer based composites towards EMI shielding applications. • Systematic review on recent development in EMI shielding materials using conducting polymer based composites. • Incorporation of suitable organic, inorganic, and other nano-fillers results in the synergistic responses. • Conducting polymer based composites have great potential in the fabrication of broadband EMI shields. • Most suitable EMI shielding polymer composites exhibited attenuation capabilities of more than 99.999%. • Main directions for future research and applications are identified.

Nandagudi A., Nagarajarao S.H., Santosh M.S., Basavaraja B.M., Malode S.J., Mascarenhas R.J., Shetti N.P.

The recent advancements in energy storage devices move towards ample storage and harnessing of energy in different forms. This includes batteries, solar cells, fuel cells, and supercapacitors . Transition metal oxides (TMOs) nanocomposite design has dramatically improved electrochemical energy storage and conversion technologies due to its vast performance and good conductivity . Herein, we have compiled a complete list of transition metal oxide composites used as electrode materials in supercapacitor applications. This includes cobalt oxides, manganese, iron, titanium, vanadium, copper, zinc, and various composites for advanced supercapacitor studies. Lastly, inference on the overall performances of different transition metal oxide composites and their advancements has been compiled. • Hydrothermal synthesis of various transition metal oxide/graphene nanostructures. • Usage of low-cost, high-performance nanostructures for supercapacitor applications. • Correlation of metal oxide nanostructures such as core-shelled structures and electrochemical performance. • Electrochemical performance of metal oxides on the addition of carbonaceous materials and polymers. • Green synthesis of metal oxide/graphene nanostructures.

Khasim S., Pasha A., Badi N., Lakshmi M., Mishra Y.K.

In this work, we propose the development of high performance and flexible supercapacitors using reduced graphene oxide (rGO) incorporated poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT–PSS) nanocomposites by secondary doping.

Prabhakar D.A., Shettigar A.K., Herbert M.A., Patel G C M., Pimenov D.Y., Giasin K., Prakash C.

Friction-stir techniques are the potential alternative to fusion-based systems for processing and welding metallic alloys and other materials. This review explores the advantages, applications, limitations, and future directions of seven friction-based techniques namely, Additive Friction Stir Deposition (AFSD), Friction Stir Additive Manufacturing (FSAM), Friction Stir Welding (FSW), Friction Stir Processing (FSP), Friction Surfacing (FS), Friction Stir Spot Welding (FSSW), and Friction Stir Lap Welding (FSLW). The basic underlying principle of these processes uses friction as a thermal energy source to weld/process/deposit materials. The common control parameters of all friction stir processing techniques are axial force, rotational speed, and weld or traverse speed. In addition, tool profiles and tool dimensions are known to influence the weld quality. The tool's rotational speed and axial force generate friction between the workpiece and tool material interface, which could plasticize the material. The additive powder bed friction stir process (APBFSP) is another new solid-state manufacturing technique that focus on fabricating the polymer matrix nanocomposites (PNC). In this, a hollow tool like AFSD and the fundamental principle of FSP are combined. The said parameters affect the quantity of material getting deposited/welded. However, weld speed/traverse speed alters the weld quality, and higher traverse speed results in porosity and voids in the welded/deposited/processed region. The only difference between AFSD and other friction stir techniques (FSTs) is that in the AFSD technique, the hollow rotating tool comprises two protrusions with different tool profiles (cylindrical, threaded cylindrical, and tapered cylindrical, square) used. Threaded cylindrical profile and tool steel as the tool material is the most commonly employed in FSTs. Apart from that, tungsten carbide is preferred for hard materials. The working principles and process parameters of FSTs that affect the part quality are discussed in detail. The above review gives the reader an understanding of the domain of FSTs that can be researched further. A summary of some of the potential research works with objectives, process parameters, and outcomes is highlighted. This will provide the readers with an overview of the work carried out by researchers across the globe. Finally, the potential research gaps for future directions to be explored soon across the globe are outlined.

Shahjouei S., Naderi S., Li J., Khan A., Chaudhary D., Farahmand G., Male S., Griessenauer C., Sabra M., Mondello S., Cernigliaro A., Khodadadi F., Dev A., Goyal N., Ranji-Burachaloo S., et. al.

AbstractBackground There is an increased attention to stroke following SARS-CoV-2. The goal of this study was to better depict the short-term risk of stroke and its associated factors among SARS-CoV-2 hospitalized patients. Methods This multicentre, multinational observational study includes hospitalized SARS-CoV-2 patients from North and South America (United States, Canada, and Brazil), Europe (Greece, Italy, Finland, and Turkey), Asia (Lebanon, Iran, and India), and Oceania (New Zealand). The outcome was the risk of subsequent stroke. Centres were included by non-probability sampling. The counts and clinical characteristics including laboratory findings and imaging of the patients with and without a subsequent stroke were recorded according to a predefined protocol. Quality, risk of bias, and heterogeneity assessments were conducted according to ROBINS-E and Cochrane Q-test. The risk of subsequent stroke was estimated through meta-analyses with random effect models. Bivariate logistic regression was used to determine the parameters with predictive outcome value. The study was reported according to the STROBE, MOOSE, and EQUATOR guidelines. Findings We received data from 26,175 hospitalized SARS-CoV-2 patients from 99 tertiary centres in 65 regions of 11 countries until May 1st, 2020. A total of 17,799 patients were included in meta-analyses. Among them, 156(0.9%) patients had a stroke—123(79%) ischaemic stroke, 27(17%) intracerebral/subarachnoid hemorrhage, and 6(4%) cerebral sinus thrombosis. Subsequent stroke risks calculated with meta-analyses, under low to moderate heterogeneity, were 0.5% among all centres in all countries, and 0.7% among countries with higher health expenditures. The need for mechanical ventilation (OR: 1.9, 95% CI:1.1–3.5, p = 0.03) and the presence of ischaemic heart disease (OR: 2.5, 95% CI:1.4–4.7, p = 0.006) were predictive of stroke. Interpretation The results of this multi-national study on hospitalized patients with SARS-CoV-2 infection indicated an overall stroke risk of 0.5%(pooled risk: 0.9%). The need for mechanical ventilation and the history of ischaemic heart disease are the independent predictors of stroke among SARS-CoV-2 patients. Funding None.

Patel Gowdru Chandrashekarappa M., Kumar S., Jagadish J., Pimenov D.Y., Giasin K.

Industries demand stringent requirements towards economical machining without hindering the surface quality while cutting high carbon high chromium (HcHcr) steel. Electrical discharge machining (EDM) of HcHcr steel aims at reducing machining cost (i.e., maximize material removal rate (MRR) and minimize tool wear rate (TWR)) with good surface quality (i.e., minimize surface roughness (SR)). A comparative study was carried out on EDM of HcHcr D2 steel (DIN EN ISO 4957) by applying Taguchi L18 experimental design considering different electrode materials (copper, graphite, and brass), dielectric fluids (distilled water and kerosene), peak current, and pulse-on-time. The process performances were analyzed with respect to material removal rate, surface roughness, and tool wear rate. Pareto analysis of variance was employed to estimate the significance of the process variables and their optimal levels for achieving lower SR and TWR and higher MRR. Hybrid Taguchi-CRITIC-Utility and Taguchi-PCA-Utility methods were implemented to determine the optimal EDM parameters. Higher MRR of 0.0632 g/min and lower SR of 1.68 µm and TWR of 0.012 g/min was attained by graphite electrode in presence of distilled water as dielectric fluid compared to the brass and copper. Additionally, a metallographic analysis was carried out to study the surface integrity on the machined surfaces. Micrographic analysis of the optimal conditions showed lower surface roughness and fewer imperfections (lesser impression, waviness surface, and micro-cracks) compared to worst conditions.

Mishra S.P., Karunakar P., Taraphder S., Yadav H.

The role of the gut microbiome in human health is becoming apparent. The major functional impact of the gut microbiome is transmitted through the microbial metabolites that are produced in the gut and interact with host cells either in the local gut environment or are absorbed into circulation to impact distant cells/organs. Short-chain fatty acids (SCFAs) are the major microbial metabolites that are produced in the gut through the fermentation of non-digestible fibers. SCFAs are known to function through various mechanisms, however, their signaling through free fatty acid receptors 2 and 3 (FFAR2/3; type of G-coupled protein receptors) is a new therapeutic approach. FFAR2/3 are widely expressed in diverse cell types in human and mice, and function as sensors of SCFAs to change several physiological and cellular functions. FFAR2/3 modulate neurological signaling, energy metabolism, intestinal cellular homeostasis, immune response, and hormone synthesis. FFAR2/3 function through Gi and/or Gq signaling, that is mediated through specific structural features of SCFAs-FFAR2/3 bindings and modulating specific signaling pathway. In this review, we discuss the wide-spread expression and structural homologies between human and mice FFAR2/3, and their role in different human health conditions. This information can unlock opportunities to weigh the potential of FFAR2/3 as a drug target to prevent human diseases.

B.J. G., Umeshaiah M., Prasannakumara B.C., N.S. S., Archana M.

The motivation behind the existing paper is to investigate the effect of space and temperature dependent heat generation/absorption, nonlinear thermal radiation on three dimensional magnetohydrodynamic Jeffrey fluid stream over a nonlinearly permeable stretching sheet in the presence of the porous medium. An electrically conducting fluid in the presence of a uniform magnetic field is taken into account. Problem formulation is developed by assuming small magnetic Reynolds number subject to boundary layer theory. The governing partial differential equations are changed to a system of ordinary differential equations. Then obtained equations are solved numerically by applying RKF-45 method. The convergence of its solutions has been verified through plots and numerical data. A detailed parametric study is carried out to explore the effects of various physical parameters on the velocity, temperature, and nanoparticles concentration profiles. Local Nusselt numbers and Sherwood number are tabulated and discussed. Some of the results of the investigation are effect of magnetic field is to suppress the velocity field, which in turn causes the enhancement of the temperature field. Further, temperature and concentration profiles show similar behavior for thermophoresis parameter, but the opposite tendency is noted in the case of Brownian motion parameter. • Three-dimensional flow of Jeffrey fluid with thermophoresis and Brownian motion is examined. • The impacts of nonlinear radiative heat and temperature dependent heat generation/absorption are also accounted. • Numerical solutions are developed of the arising problem via Runge-Kutta based shooting approach. • Exploration of the impacts of pertinent parameters on velocity, temperature fields are performed via graphical illustrations.

Belavadi S.V., Rajagopal S., R R., Mohan R.

In the past few decades, many urban areas around the world have suffered from severe air pollution and the health hazards that come with it, making gathering real-time air quality and air quality forecasting very important to take preventive and corrective measures. This paper proposes a scalable architecture to monitor and gather real-time air pollutant concentration data from various places and to use this data to forecast future air pollutant concentrations. Two sources are used to collect air quality data. The first being a wireless sensor network that gathers and sends pollutant concentrations to a server, with its sensor nodes deployed in various locations in Bengaluru city in South India. The second source is the real-time air quality data gathered and made available by the Government of India as a part of its Open Data initiative. Both sources provide average concentrations of various air pollutants on an hourly basis. Due to its proven track record of success with time-series data, a Long Short-Term Memory (LSTM) Recurrent Neural Network (RNN) model was chosen to perform the task of air quality forecasting. This paper critically analyses the performance of the model in two regions that exhibit a significant difference in temporal variations in air quality. As these variations increase, the model suffers performance degradation necessitating adaptive modelling.

Surendra B.S., Shashi Shekhar T.R., Veerabhadraswamy M., Nagaswarupa H.P., Prashantha S.C., Geethanjali G.C., Likitha C.

Today world is facing water pollution resulting from various sectors and presenting serious ecological concerns. The reusability of polluted water could be a promising study for the sustainable wastewater management strategy. In this, prepared ZnFe2O4 nano-photocatalyst was employed for photocatalytic degradation of organic dye pollutants namely Acid Red 88 (AR-88), Acid Orange 8 (AO 8) and Malachite Green (MG) under Sun light and UV irradiation. The UV-induced dye degraded wastewater samples were used to examine the green assessment towards the growth of Eleusine coracana (Finger millet) and Vigna unguiculata (Black eyed beans) plant. The results showed excellent plant growth in dye degraded wastewater sample noticed in the period of 3–5 days compared to pure water as control and with retard growth observed in dye solution. Thus, present research reported that the sustainability issues related to photodegradation of contaminated dye solution using prepared nano material was tested and efficiently using treated waste water in growing plants.