Research News

Dr Lakhveer Singh, Assistant Professor, Department of Environmental Science, SRM University-AP, Andhra Pradesh published an article titled “Remediation strategies for mitigation of phthalate pollution: Challenges and future perspectives” in the Journal of Hazardous Materials, with an Impact Factor of 9.03. In recent times, there has been an escalating concern over the risk of phthalate exposure leading to adverse effects on human health and the environment. Dr Lakhveer acknowledged the necessity of understanding the current status of phthalate pollution, their sources, exposure routes, and health impacts, along with understanding the remediation technologies for mitigating such issues.

In this collaborative work between Indian Institute of Technology, Delhi, Jawaharlal Nehru University, and SRM AP, Dr Lakhveer enumerates the major phthalates in use today, shares insights on the ever-increasing data on health burdens posed by phthalates and simultaneously, highlights the recent advancements in research to alleviate phthalate contamination from the environment. Tracing their environmental fate, he addresses the growing health hazard concerns imposed by phthalates, along with focusing on understanding the different physical, chemical, and biological treatment of phthalates that are currently being used.

Dr Lakhveer explains, “Depending on the degree and nature of contamination, PAEs can be eliminated from different environmental matrices via various available processes such as adsorption, coagulation-flocculation, microbial biodegradation, phytoremediation, photocatalysis, and advanced oxidation processes. However, the efficiency of all these processes depends on various factors including inherent Physico-chemical nature of phthalates, environmental factors, and technological sufficiency.” Thus, advancing his research work in the future, Dr Lakhveer will opt for a holistic approach to develop novel processes for the remediation.

Dr Nimai Mishra, Assistant Professor, Department of Chemistry, SRM University-AP, Andhra Pradesh, along with his research group comprising of students pursuing PhD under him, Ms. V.G.Vasavi Dutt and Mr. Syed Akhil, have published a comprehensive mini review titled “Surface Passivation Strategies for Improving Photoluminescence and Stability of Cesium Lead Halide Perovskite Nanocrystals” in the Journal “ChemNanoMat” (Wiley-VCH) with an Impact Factor of 3.4.

Cesium lead halide (CsPbX 3) perovskite nanocrystals (NCs) is emerging as an intriguing subject for the optoelectronics for its excellent optical properties and exceptional colour tunability. However, applicability of the materials become a major challenge due to their degenerative property. Consequently, researchers focus on developing various approaches to enhance the photoluminescence properties and stability of CsPbX 3 perovskite NCs. In the paper, Dr Mishras’s group reviews some of the promising approaches such as post‐synthetic modification, ligand exchange, and insitu addition.

Further, the strategies summarized in this paper will enable the production of high-quality nanocrystals having the potential to be used as active material in LED devices. In the future, Dr Mishra and his group plans on utilizing some of these surface passivation techniques to develop prototype LED devices using high quality nanocrystals.

Read the full paper: Please Click Here

Utilizing photosynthetic microalgae to produce renewable biofuel

Dr Imran Y Pancha, Assistant Professor, Department of Biological Sciences, SRM University-AP, Andhra Pradesh has received an outstanding total outlay of Rs.27 lakhs from the DST, Government of India, to work on “Chemical modulator based microalgal biorefinery for the production of biofuels and bioproducts”. Dr Imran was fascinated by the potential of microalgae to reduce greenhouse gases (GHGs) as well as its ability to accumulate a high amount of energy reserved molecules such as lipids/starch in the cells. Through his research, Dr Imran will be understanding the mechanism behind this and also, exploit microalgae for biofuel production.

Due to the development of industrialization and modernization, global energy demand is continuously increasing. Given that the fossil fuel energy reserve is limited, and its utilization causes various serious environmental issues such as global warming and the accumulation of GHGs in the atmosphere, renewable energy obtained from various biomass is a potential alternative to reduce atmospheric GHGs and the dependency on fossil-based fuel. Microalgae is one of the promising resources among various biomass since it has a high growth rate and photosynthetic ability in comparison to other terrestrial crop plants. Microalgae also accumulate a high amount of lipids and carbohydrates in the cell. Moreover, these microalgae can be cultivated in wastewater or seawater, which avoids the food versus fuel debate.

Dr Imran explains, “Microalgae usually accumulate lipid under stress conditions such as nitrogen starvation, which results in lower biomass production, limiting the commercialization of algal biofuel. The present research’s primary objective is to uncouple growth and lipid production pathway in the microalgae using chemical modulators. Utilization of such chemicals is also effortless in large scale production compared to the standard starvation approach. The next aim is to develop a process to extract multiple products such as pigments, lipids, and carbohydrates from single microalgal biomass. The development of such a biorefinery approach will lower the overall cost of the process and make it more economical on a large scale. To conclude, the focus of the project will be on utilizing photosynthetic microalgae to produce renewable biofuel and other commercially important products in a biorefinery manner. Utilization of microalgae will not only help to produce green fuel but also help in reducing atmospheric carbon dioxide (CO2) which creates several environmental issues.”

Using the SERB-SRG grant, microalgal cultivation facility will be established at SRM university-AP. The long-term goal of Dr Imran’s research group is to understand the molecular mechanism behind the accumulation of energy reserved molecules in the microalgae. Understanding such mechanisms will help to develop sustainable technology for the production of renewable biofuels from microalgae.

Connecting the dots between Mathematics and Physics of the hydrodynamic instability known as Viscous Fingering (VF)

DST, Government of India, sanctioned a total outlay of Rs.14.63 lakhs to Dr Tapan Kumar Hota, Assistant Professor, Department of Mathematics, SRM University-AP, Andhra Pradesh, for pursuing research on “Mathematical analysis and Adjoint Based Stability for a Coupled Convection-Diffusion equation in Miscible Displacement”. Hydrodynamic Stability (Instability) is a study of an equilibrium point subject to small and/or medium disturbances. This assists in understanding several complicated natural phenomena such as fluid transition from laminar to turbulent, chemical mixing, formation of cloud, and others. The available stability analysis is unable to address the early-time evolution of the VF process. The early-time behaviour of the system helps us to choose the parameters that are responsible for the long-time behaviour of the coupled PDEs. To achieve the target, we need to address the linear stability of the system from the study of the singular-value-decomposition instead of traditional eigenvalue analysis. As the system is non-autonomous, the eigenvectors/eigenvalues may not be physically relevant. Further, it is required to confirm our linear stability analysis by mathematical analysis of the coupled non-linear PDEs.

‘The nonmonotonic viscosity profile when a high mobile fluid is displacing a less mobile fluid. There is a potentially unstable region, where the viscosity increases in the flow direction, followed in the downstream direction by a potentially stable region, where the viscosity decreases in the flow direction. The disturbance structure is computed using the singular-value decomposition of the propagator matrix. Reference: Hota & Mishra, Journal of Fluid Mech, Vol. 856, pp:552-579, 2018.’

Dr Tapan is keen on studying other branches of science to provide the correct mathematical approach to address the issues. His project will address one of the hydrodynamic instabilities known as viscous fingering (VF). It forms when a high mobile fluid displaces a low mobile fluid. It has enormous implications in the field of Chemical Engineering Science, Petroleum Engineering, Chromatography, and Oil Extraction process. He explains, “I will study this instability from a mathematician’s point of view, more precisely, to address the mathematical analysis of coupled partial differential equations (PDEs). The system that governs the VF is non-autonomous and there is no readily available stability analysis that can represent Physics, based on robust mathematical analysis. My aim is to connect the dots between mathematics and physics of the VF.”

Infrastructure and laboratory facilities are crucial to conduct research. Upon receiving approval from a prestigious organization like SERB (Science and Engineering Research Board), Govt. of India, Dr. Tapan is entitled to this unique opportunity to serve the scientific community. He divulges, “The award is not only a recognition to me but also to the SRM University, AP. The University will be more visible in the world of research and can attract more eminent scientists and researchers to make the University their second home.” Quoting Master Oogway, ‘Yesterday is history, Tomorrow is a mystery… Today is a gift, that’s why it is called present.’, Dr Tapan is eager to commence working on his project at the earliest, and looks forward to enjoying the process of accomplishing the task.

Pursuit of discovering new drug molecules to combat diseases

Dr Writoban Basu Ball, Assistant Professor, Department of Biological Sciences, received an outlay of Rs.26.34 lakhs from DBT, Government of India to pursue research on “Targeting Kennedy pathway of cellular phosphatidylethanolamine biosynthesis as a common therapeutic strategy against protozoan parasites like Leishmania donovani, Trypanosoma brucei and Entamoeba histolytica.” Disease-causing intracellular parasites present serious health challenges, which could be fatal if left untreated. For example, Leishmania donovani and Trypanosoma brucei are the causative agents of visceral leishmaniasis and sleeping sickness, respectively. Entamoeba histolytica causes amoebiasis and 100,000 people die each year world-wide from amoebiasis-related complications. The current treatment regimen against these diseases consists of drugs that possess severe toxicity and drug resistance. Toxicity is detrimental to health and drug-resistance causes unresponsiveness of the drug to the parasite, rendering the drug ineffective. Therefore, it has become imperative to discover new drug molecules to combat these diseases.

In his study, Dr Writoban proposes to repurpose an FDA-approved drug meclizine, which can be used as a potential drug against dreadful parasitic infections. He explains. “One rational way to discover new and effective drugs entails identifying pharmacological targets against unique yet essential parasite metabolic pathways which are either absent or redundant in hosts (in the present case humans). One such central metabolic pathway in L. donovani, T. brucei, and E. histolytica is the Kennedy pathway for the biosynthesis of phosphatidylethanolamine (PE), a major lipid molecule of the cell. Without the presence of this lipid molecule, the cellular membranes (plasma membrane, organellar membranes) cannot form. Therefore, the Kennedy pathway is indispensable to parasite survival. On the contrary, in humans, although the Kennedy pathway is present, other pathway of PE biosynthesis is predominant. Hence, the Kennedy pathway offers a potential target to disrupt PE biosynthesis in these parasites without causing any side effects in the human host. In this context, meclizine, an over the counter anti-nausea drug, has been shown to disrupt the Kennedy pathway.”

Dr Writoban’s research is oriented to find safe cures for dreadful parasitic diseases that mostly plagues the underprivileged section of the developing countries like India, and countries of the sub-Saharan Africa. He believes, “The successful implementation of the proposed research scheme would benefit a lot of underprivileged people belonging to the underdeveloped and developing countries, as well as reduce the disease burden of those countries.” Further, Dr Writoban emphasizes, “Getting the grant is only the job half done. I would like to guide this proposal to a fruitful completion so that it can benefit people who need it most. I really want to take this project beyond the bounds of a mere academic exercise.

Smart algorithm to optimize performance of the heterogeneous multi-cloud network

Dr Sambit Kumar Mishra

As the world goes more digital in the future, the dependability on cloud computing is going to be more. The availability of high-capacity networks, low-cost computers and storage devices as well as the widespread adoption of hardware virtualization, service-oriented architecture and autonomic and utility computing has led to growth in cloud computing. But is it enough? How to improve its performance? How to make it more reliable with high-end technology and impeccable performance quality? Dr Sambit Kumar Mishra’s research has an answer to that.

System Model for Multi-cloud Networks Dr Sambit Kumar Mishra, Assistant Professor, Computer Science and Engineering has published a paper “Energy-Aware Task Allocation for Multi-Cloud Networks” in renowned journal IEEE ACCESS with an Impact Factor: 3.745. The research was done in collaboration with Dr Sonali Mishra, SOA (Deemed to be) University Bhubaneswar, India; Dr Ahmed Alsayat, College of Computer and Information Sciences Jouf University, Al-Jouf, Saudi Arabia; Dr N Z Jhanjhi and Dr Mamoona Humayun, School of Computer Science and Engineering (SCE), Taylor’s University, Malaysia; Dr Ashish Kr. Luhach, The PNG University of Technology, Papua New Guinea Lae, Morobe; Dr Kshira Sagar Sahoo, VNRVJIET, Hyderabad, India.

Example of Direct Acyclic Graph (DAG)with four TasksIn recent years, the growth rate of Cloud computing technology is exponentially, mainly for its extraordinary services with expanding computation power, the possibility of massive storage and all other services with the maintained quality of services (QoS). The task allocation is one of the best solutions to improve different performance parameters in the cloud, but when multiple heterogeneous clouds come into the picture, the allocation problem becomes more challenging. This research work proposed a resource-based task allocation algorithm. The same is implemented and analysed to understand the improved performance of the heterogeneous multi-cloud network. The proposed task allocation algorithm (Energy-aware Task Allocation in Multi-Cloud Networks (ETAMCN)) minimizes the overall energy consumption and also reduces the makespan. The results show that the makespan is approximately overlapped for different tasks and does not show a significant difference. However, the average energy consumption improved through ETAMCN is approximately 14%, 6.3%, and 2.8% in opposed to the random allocation algorithm, Cloud Z-Score Normalization (CZSN) algorithm, and multi-objective scheduling algorithm with Fuzzy resource utilization (FR-MOS), respectively. An observation of the average SLA-violation of ETAMCN for different scenarios is performed.

Energy Consumption Vs SLA Violation when
the number of VMs varies and the number of Task is 100.The multi-cloud strategy offers flexibility to service providers. It allows businesses to be productive while using the proper set of services to optimize their opportunities. Adopting a multi-cloud network enables an enterprise to implement a “best of breed” model for the services. Organizations’ ability to choose the vendor that offers the best price for their workload is added significant advantage of multi-cloud. Thus, the optimization of energy consumption in a multi-cloud environment is necessary for the current generation.

However, this proposed work has not considered any priority-oriented users, such as task execution through reserve resource in the network, which will be considered as his future work. The future work also aims to propose a task cum resource-aware scheduling approach that will exploit the nature of the presented workload and efficiently map on the available Cloud resources so that energy consumption will optimize.

Link to the research paper: Please Click Here

Dr Karthik Rajendran, Department of Environmental Science, SRM University-AP, Andhra Pradesh, has published a paper on “Mechanism and challenges behind algae as a wastewater treatment choice for bioenergy production and beyond” in the Fuel journal, which is published by Elsevier. His research work encompasses wastewater treatment using algae for bioenergy production. In his words, “Conventional wastewater treatment systems use activated sludge processes. This process not only uses energy, but also results in emissions. Wastewater contains valuable nutrients and energy recovery options, which are the least explored. Algae helps in reducing emissions by sequestering carbon which leads to negative emissions. The research highlights different mechanisms of using algae for wastewater treatment.”

India as a country is under water-stress and the need for recycling and reusing water is on the rise. The wastewater contains essential nutrients for agriculture and plant growth which are limited resources available to us. Such limitations have inspired efforts to provide solutions to work on algae as a wastewater treatment method. Processes for the same are studied in this paper to comprehend its efficiency and for developing a sustainable choice for the industry. This work will enable the scientists and industrialists to appreciate the usage of algae as an option for wastewater treatment.

Dr Karthik further provides insights on his current research proceedings by saying, “We are currently working on recovering nutrients including phosphorus and nitrogen from wastewater. We are currently performing the theoretical evaluation of the amount of nutrients that can be recovered from different nutrient recovery technologies including microalgae. Such systems not only reduce emissions, but also reduce the amount of virgin materials used.”

Link to the research paper: Please Click Here

An intriguing paper on “Recent developments and strategies in genome engineering and integrated fermentation approaches for biobutanol production from microalgae” has been published in Fuel by Dr Karthik Rajendran, Department of Environmental Science, SRM University-AP, Andhra Pradesh. Fossil fuels such as petrol, coal, and natural gas deplete natural resources and increase emissions leading to global warming and climate change. As the transportation sector is heavily dependent on liquid fuels and only a few alternatives are available including ethanol, there is an urgent need for higher energy-dense liquid fuel, which is researched across the world, and butanol is considered as an alternative.

There is a constant conflict between food and fuel where the debate lies on whether to swap agricultural lands to produce fuel. An alternative to tackle this problem is identified to be microalgae which is the third-generation feedstock. This feedstock does not conflict with the production of food, as agricultural land is not necessary for its creation. In his work, Dr. Karthik explored different mechanisms for producing butanol from microalgae.

Dr Karthik has been curious on developing industrially feasible solutions for bioenergy, waste management, and sustainability as these industrial solutions are least researched and transferred. This has motivated him to work on economically viable solutions for industries. Dr Karthik explains, “In this work, the mechanisms and fermentation strategies of butanol production from microalgae is explored. Advancing with the research, our team will work on identification of the bottlenecks pertaining to such pathways along with assessing the profitability of producing butanol from microalgae.”

Link to the research paper: Please Click Here

Amine-free air- stable perovskite nanocrystals for future optoelectronic devices

Dr. Nimai Mishra, Department of Chemistry, SRM University-AP, Andhra Pradesh, along with his research group comprising of his Ph.D. students – Mr. Syed Akhil and Ms. V.G.Vasavi Dutt, have published “Completely Amine-free Open Atmospheric Synthesis of High Quality Cesium Lead Bromide (CsPbBr3) Perovskite Nanocrystals” in the journal “Chemistry-A European Journal” (Wiley-VCH, Impact factor 4.86).

Cesium Lead Halide Perovskite Nanocrystals (NCs) CsPbX3 (X=Cl, Br, and I) have gained popularity in the last few years due to their high Photoluminescence Quantum Yield (PLQY) owning for Light Emitting Diodes (LEDs), and other significant applications in Photovoltaic and Optoelectronics. Dr Mishra says, “In this research work, we demonstrated a facile and efficient amine- free synthesis of Cesium Lead Bromide Perovskite Nanocrystals using Hydrobromic acid as halide source and n-trioctylphosphine (TOP) as ligand in open atmospheric conditions.” He further explains, “The hydrobromic acid (HBr) served as labile source of bromide ion, thus, this three-precursor (separate precursors for Cs-Pb-Br) approach gives more control over conventional single-source precursor for Pb and Br (PbBr2). The use of HBr paved the way to eliminate oleylamine, as a result, we can completely exclude the formation of labile oleylammonium ion halide.”

Dr Mishra and his research group extensively studied the various Cs-Pb-Br molar ratio and found an optimum condition that was able to stabilize with high PLQY CsPbBr3 NCs. These completely amine-free CsPbBr3 perovskite NCs synthesized using bromine-rich condition, exhibit good stability and durability for more than three months in the form of colloidal solutions and films respectively. Furthermore, they demonstrated stable tunable emission across a wide spectral range, via anion exchange process. More significantly, their work presents an open atmospheric stable CsPbBr3 NCs films demonstrating high photoluminescence (PL), which can be further used for optoelectronic device applications.

These high-quality nanocrystals have the potential to be used as active material in LED devices. Advancing his research, Dr Mishra and his team are planning to make a prototype LED device using their nanocrystals.

Link to the research paper: Please Click Here

Simulating time-variant channel impulse response for mmWave I2I channels using Doppler spread information

Dr Anirban Ghosh

Dr Anirban Ghosh, Assistant Professor, Electronics and Communication Engineering, has recently published a paper titled “Time Variance of 60 GHz VI2I channel”. The paper is published in the renowned journal Elsevier-Vehicular Communication with an Impact Factor of 4.7. This paper explores the implementation challenges in unlicensed 60 GHz frequency band for autonomous vehicle infrastructure. This work has been implemented in collaboration with his colleagues from NIT Durgapur and collaborators from Brno University under the aegis of Prof. Ales Prokes. This work is also funded by the Science Foundation grant (Czech) and National Sustainability Program grant (Czech) and DST-Core Research Grant(India).

Fig 1: Field test setup at the measurement site

Smart cities are cities on the move; having a mission of delivering people and goods with zero congestion, zero fatality and zero energy wastage. For realising this mission, a smart city needs an intelligent transport system (ITS). As far as the communication aspect of ITS is concerned, historically, the urban ITS planners were more concerned about vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) modes of communication. This is because the V2V and V2I channels are essentially wireless, and establishing reliable low-latency links over these channels is challenging. Infrastructure-to-infrastructure (I2I) communication is also an integral part of the ITS initiative, and due to their rapid, dynamic and non-invasive nature of the installation, wireless I2I links are preferred over wired links in several smart-road based ITS applications. In order to implement wireless I2I communication, transceivers may be fitted with different kinds of roadside units (RSUs), e.g., short height traffic signposts, overhead gantries, and cantilever sign supports. The traditional role of these RSUs is to support the basic ITS goals, i.e. driver assistance or traffic management. As the vehicular networks scale-up, ITS computations are being shifted to the edge, and the RSUs are going to play more prominent roles in the form of edge computing devices. For example, RSUs can form the cloudlet layer of a vehicular fog computing (VFC) architecture for the internet of vehicles (IoV).

Vehicular wireless I2I channels realise fixed-to-fixed (F2F) radio communication between two RSUs. For any F2F radio channel with stationary transmitter (TX) and receiver (RX), the time-variance is caused by the mobility of the scatterers. These mobile scatterers, say passersby for an indoor scenario, or passing vehicles for an outdoor scenario, cause changes in path lengths in a fading multipath channel. When viewed in frequency-domain, this yields a change in carrier frequency termed as Doppler shift which is proportional to the velocity of the scatterer, and the spectral broadening caused by the time rate of change of the channel is measured with the Doppler spread. Information about Doppler spread is critical for V2V applications such as platooning. In the context of V2I applications, accurate estimation of the Doppler spread is required for designing adaptive transceivers, smart antennas and for determining cellular handoffs. Doppler spread information can also be used for I2I applications like speed estimation. The radar-based solution has a lower latency compared to a camera-based solution, owing to the video acquisition and processing time of the later. As the Doppler shift is a linear function of the carrier frequency, it is of greater concern while moving up in the frequency ladder to the millimetre wave (mmWave) regime. The Doppler spread in the unlicensed 60 GHz mmWave band would be 10-30 times that in the current sub-6 GHz band, with a range spanning from 10 Hz to 20 kHz depending on the velocity of the scatterers. Moreover, compared to V2V links, the effect of moving scatterers is much more pronounced in F2F links; walking pedestrians with a velocity order of ∼ 1 m/s or even the tree leaves fluttering in the wind are important for F2F channel modelling. For highways, the moving vehicles have a velocity an order higher (> 10 m/s) and contribute significantly to the time-variance of the roadside wireless I2I links.

Fig 2: Comparison of the measured and
proposed models of ACF and Doppler
Spectrum with existing analytical models

In this paper, Dr Ghosh studied the time-variance of a roadside infrastructure to infrastructure (I2I) channel operating at 60 GHz millimetre wave (mmWave) band, where the time-variance is caused by moving vehicles acting as scatterers. At first, measurement data is obtained by placing the transmitter (TX) and the receiver (RX) at different heights to emulate a link between two nonidentical roadside units (RSUs), and time-domain channel sounding is performed by sending complementary Golay sequences from the TX to the RX. A linear piecewise interpolation of the corresponding temporal auto-correlation function (ACF) is used to find the Doppler spread of the I2I channel, where their interpolation method compensates for a slower sampling rate. Next, a framework is presented for the time-variant channel impulse response (CIR) simulation, which focuses on moving scatterers only and validates the linear piecewise ACF model. The framework is useful for time-variant vehicular I2I channel simulation and in speed estimation related vehicular applications. Finally, a double-slope curve-fitted analytical model for ACF is proposed as a generalisation to the linear piecewise model. The proposed model and its Doppler spectrum are found to be in agreement with the analytical results for fixed-to-fixed (F2F) channels with moving scatterers and matches perfectly with the measured data. “Our research has explained a framework for simulating time-variant channel impulse response (CIR) for mmWave I2I channels with moving scatterers using Doppler spread information – which provides means to study the various characteristics of an I2I channel even without carrying out any expensive channel sounding campaign”, said Dr Ghosh.

Dr Ghosh and his collaborators are currently exploring further challenges in communication between vehicles (V2V) in the same frequency range (60 GHz).

To know more about the paper, please visit- https://www.sciencedirect.com/science/article/abs/pii/S2214209620300590?dgcid=coauthor