Microbial fuel cells (MFCs) are a sustainable technology capable of generating direct current while simultaneously treating wastewater. MFC reactors have commonly utilized catholytes such as phosphate buffer solutions, direct oxygen injection, or air cathodes. However, in this study, both abiotic and biotic cathodes were explored. Abiotic cathodes were tested using acidic water (pH 2), while biotic cathodes incorporated either mixed microbial cultures or Scenedesmus obliquus in the cathodic chamber for the simultaneous treatment of synthetic and real domestic wastewater, bioelectricity generation, and algal biomass production. The results showed that a chemical oxygen demand (COD) load of 5.35 g/L, using acidic water as the catholyte (abiotic cathode), produced the highest cell voltage of 205.55 mV, with continuous current density and volumetric power density reaching 60.45 mA/m2 and 84.50 mW/m3, respectively. COD removal efficiency was 93.85%, and coulombic efficiency (CE) reached 77.38%. In comparison, the algal biocathode MFC (ABM) with the same COD load exhibited a continuous current density of 23.93 mA/m2 and a volumetric power density of 13.24 mW/m3, achieving 92.52% COD removal efficiency and 41.88% CE. The growth of Scenedesmus obliquus in the ABM increased from 0.1 g/L to 0.93 g/L, with a maximum specific growth rate (μ) of 0.0325 h−1. During nitrogen-rich wastewater treatment, in closed-circuit (CCV) mode, using a biotic cathode with mixed microbial culture and a 2 g/L NH4Cl load (CCV-2) produced the highest current density (23.69 mA/m2) and volumetric power density (12.97 mW/m3). COD, total Kjeldahl nitrogen (TKN), nitrite, and nitrate removal rates were also highest in CCV-2 at 90.25%, 92.18%, 85.78%, and 86.53%, respectively. The 5 L lab-scale ABM reactor, operating with an organic loading rate (OLR) of 1.951 kg COD/m3/d and a hydraulic retention time (HRT) of 40 hours, achieved the highest current density of 121.82 mA/m2 and a volumetric power density of 343.10 mW/m3.COD and total dissolved solids (TDS) removal efficiencies were 91.25% and 65.01%, respectively. Algal biomass concentration increased from 3.18 g/L at the start of the continuous experiment (day 17) to 31.66 g/L by the end (day 135), with dissolved oxygen (DO) ranging from 14.11 to 14.18 mg/L and a peak specific microalgae growth rate of 0.085 d−1. Overall, the study demonstrated that integrating abiotic and biotic cathodes in MFCs can effectively enhance bioelectricity generation, wastewater treatment efficiency, and algal biomass production, highlighting their potential for sustainable energy recovery and resource recovery applications. Keywords: Algal biomass, Bioelectricity, Hydraulic retention time, Organic loading rate, 16S microbiome profiling

With ever expanding urban limits, waste management is an unaffordable challenge to the urban land economy. Single-use plastic waste is one of the recalcitrant components of increasing municipal solid waste volume. Biotechnological studies unveiled the potential of some of the isolated bacterial and fungal strains to bioremediate single-use plastic wastes. In the present study, soil-like fraction (SLF) was collected from Greater Warangal Municipal Solid Waste Management Park, Rampur, Warangal, Telangana, India. Pseudomonas fluorescens and Bacillus Circulans were artificially induced into the SLF to accelerate the process of biodegradation of single-use plastic waste. Treatment batches were maintained at both controlled and uncontrolled environmental conditions in the laboratory. Impact of various constituents involved in the treatment process were analyzed using FTIR spectroscopy, loss in ignition, CHNS analysis and Carbon dioxide evolution tests. The results justified that both the species could thrive in SLF under uncontrolled condition as well. Pseudomonas fluorescens was found to perform better than Bacillus Circulans owing to their higher adaptability under adverse conditions and higher enzymatic reactions. Biodegradability of Pseudomonas fluorescens to degrade various single-use plastic wastes was further investigated under field conditions. The results indicated that the micro-organism in powder form can be applied as a biolayer in landfill liner system to enhance the biodegradation of single-use plastic wastes.

Anthropogenic impacts have drastically influenced the way that land is used, and as time goes on, its impact on the environment will have a significant effect on the utilization of land in the future. The Land Use Land Cover (LULC) maps were classified in Google Earth Engine platform using three different machine learning algorithms namely, Support Vector Machine (SVM), Random Forest (RF), and Classification and Regression Trees (CART) for Munneru basin, India. The future LULC’s are projected using the Dyna-CLUE model for three user defined scenarios such as past trend, drastic change in built-up and barren land and restricted agricultural land. This study evaluates how LULC and climate change together affect hydrology of the basin for future climate change scenarios using Soil and Water Assessment Tool (SWAT). CMIP6 climate data was used under three scenarios SSP245, SSP370 and SSP585 which was then ensemble using the Reliable Ensemble Averaging (REA) method at each grid for both precipitation and temperature data. The SUFI2 algorithm in SWAT-CUP tool is used to calibrate and validate the SWAT model for the years 1983–2017. Under both LULC scenarios and SSP climate change scenarios, for the baseline period (1983–2014) as well as for three future periods the average monthly streamflow is projected: the near-future (2025–2040), mid-future (2041–2070) and far-future (2071–2100). In light of projected LULC under climate change scenarios, the study's findings can be used to plan and develop short term and long-term integrated water management strategies for the basin.

The primary objective of this thesis is to investigate the stability of micropolar fluid flow in a channel. We examine the effects of double diffusion, magnetic fields, thermal radiation, chemical reactions, internal heat sources, and Soret effects. The study starts with a linear stability analysis in a vertical channel and then extends to linear and nonlinear stability analyses in a horizontal porous layer. Finally, the Hadley-Prats flow of micropolar fluid in horizontal porous layers is investigated.

A solar photovoltaic (SPV) grid-tied inverter is utilized to mitigate current-related power quality issues while ensuring efficient energy conversion. A model predictive control (MPC) strategy is implemented to regulate inverter operation, enabling improved efficiency of the inverter, fast transient response, and effective power flow control. Multi-criteria decision- making (MCDM) methods are employed to optimize the switching pattern, ensuring efficient operation with minimized losses and enhanced overall system performance. An adaptive DC- link voltage control method is applied to reduce voltage stress, enhance dynamic response, and improve overall system efficiency. The integration of a battery storage system facilitates improved grid support by enhancing power availability, stabilizing voltage fluctuations, and ensuring seamless energy transfer under dynamic changes of load power and variations of SPV power. Validation through simulation and experimental analysis confirms significant improvements in power quality, reduced switching stress, enhanced energy utilization, and better system reliability for grid-tied applications.

Present study aims to assess the horizontal alignment design consistency of two-lane rural highway sections by developing the operating speed model best suits to safety criteria design. Field data collected on 41 sites in various parts of National Highways. The geometric variables like curve radius, curve length, degree of curvature, deflection angle, and preceding tangent length are collected using total station instrument. The speed data collected at various horizontal curve sections and the preceding tangents of the curve sections are analysed to assess the 85 th percentile speed of. The statistical distribution analysis found that vehicle type speed data was either follows normal distribution or Log-normal distribution whereas, mixed traffic speed data follows more than one type of statistical distribution. The first-order reliability method and system reliability analysis are performed by considering stopping sight distance and superelevation for estimating probability of non-compliance. The analysis showed a high probability of non-compliance with superelevation than the stopping sight distance as design elements. The k-means clustering analysis performed for developing safety evaluation criterion by considering the estimated reliability indices. The study defines criteria based on stopping sight distance, superelevation, and system reliability as unsafe, tolerable, and safe. Finally, the study designed calibration charts by using varying middle ordinates at various levels of probability of non-compliance for evaluating the safety consequences of different design alternatives.

Bioactive materials, particularly mesoporous bioactive glasses (MBGs), have gained significant attention in biomedical research for their potential in promoting tissue regeneration, especially in bone repair and drug delivery systems. MBGs are engineered to bond with bone tissue, aiding in healing and regeneration. Their mesoporous structure provides a high surface area and tunable properties, making them ideal for biomedical applications. For effective clinical use, bioactive materials must meet key requirements: bioactivity, biocompatibility, and antibacterial properties. Bioactivity promotes bone bonding, biocompatibility ensures non-toxicity, and antibacterial properties are essential for preventing infection in implantable materials. This thesis aims to fabricate and study the structural, textural, biological and antibacterial properties of SiO₂-CaO-P₂O₅-Li₂O-Ga 2 O 3 MBGs and further improving their functionality by adding rare-earth elements (Tb 2 O 3 , Sm 2 O 3 , and Eu 2 O 3 ) in concentrations of 0.5–2 mol%. The obtained findings revealed that, the as-synthesized MBGs (particle size <250 nm) exhibited well-ordered mesopores (2–50 nm) with uniform distribution. The biological characterizations showed improved cell viability, excellent blood compatibility (Hemolysis < 5%), and enhanced osteogenic stimulation. Further, the rare-earth doping also boosted antibacterial efficacy and fluorescence-based tissue monitoring. Notably, Eu-doped Ga-MBGs demonstrated promising potential for bone tissue regeneration, infection control, and bioimaging, making them highly suitable for advanced bone repair and theranostic applications. This research contributes to overall the development of advanced bioactive materials, with the potential for a wide range of applications in regenerative medicine, offering promising solutions to the challenges of bone regeneration, tissue repair, and infection prevention.

In the context of reducing CO 2 emissions, the one prospect currently practiced is replacing Portland Cement with high volumes of supplementary cementitious materials (SCMs). Utilizing locally available SCMs like fly ash and ground granulated blast furnace slag (GGBFS) reduces landfill waste and environmental pollution. Alkali activation of clinker-free SCMs such as fly ash, GGBFS, etc., produces alkali-activated concrete (AAC). However, it has limited tensile strength and poor ductility due to its quasi-brittle nature. To overcome these weaknesses, steel bars are incorporated as reinforcement in AAC structures. While reinforcement improves ductility up to some extent, Fibre Reinforced Alkali Activated Concrete (FRAAC) offers further enhancements. The inclusion of short and long fibres significantly improves ductility and tensile strength. FRAAC also controls crack propagation and enhances overall performance. This thesis investigates the impact of mono and hybrid fibres on the fresh properties, mechanical performance, and stress-strain behaviour of alkali-activated concrete (AAC). Analytical models based on the modified reinforcing index (MRIv) are developed to predict stress-strain behaviour in compression and tension. PVA (short) and steel (long) fibres were used, with fibre addition improving mechanical properties, stress-strain and crack behaviour of AAC. PVA fibres enhanced pre-crack behaviour, while steel fibres improved post-peak performance. Hybrid fibres significantly enhanced both pre-peak and post-crack behaviour in AAC.

The evolution of the modern wireless communication system for 5G and beyond systems has led to a tremendous increase in the demand for high data rates, massive connectivity, and reduced latency. In orthogonal multiple access (OMA) techniques (e.g., FDMA, TDMA, CDMA, and OFDMA), available resources determine the number of users that can be connected to the network. Non-orthogonal multiple access (NOMA) scheme has emerged as a promising multiple access technology in future wireless communications as it supports massive connectivity compared to the existing OMA methods. In this research, a novel multi-carrier index keying based non-orthogonal multiple access (MCIK- NOMA) system is proposed. Unlike the classical scheme, the proposed system sends the information through both index domain and constellation domain symbols. The simulation results show that the proposed MCIK-NOMA system outperforms NOMA, OMA, and other existing schemes in terms of bit error rate, spectral efficiency, and energy efficiency. The performance of MCIK-NOMA under different channel state information (CSI) conditions - perfect, fixed, and MMSE-based variable CSI uncertainty is analysed over Nakagami-m fading channel. The performance of the MCIK-NOMA system is examined over various generalized fading channels and different detection techniques. The proposed MCIK-NOMA system is a better 6G candidate to serve the next generation's wireless communication needs.