Mapana Journal of Sciences

Unlocking the Potential of Microalgae: Renewable Biofuel Technologies, Barriers, and Future Directions

Amal Halder, Sampiya Banerjee — Tue, 22 Jul 2025 00:00:00 +0000

Researchers are looking for an alternative source of energy due to the increase in energy demand and environmental pollution caused by fossil fuels. Recent reports said that microalgae are efficient for biofuel production due to their high growth ability, low production cost and potential to grow in severe environments. There are many photosynthetic microalgae that consume CO₂ and sunlight for growth in biomass and thus provide a promising source of bioenergy. This review paper presents the recent technologies to produce microalgal biofuel. Besides this, the cultivation and harvesting processes and environmental factors that influence the microalgal biofuel production have also been discussed. This review paper also discusses how to attain carbon neutrality through several biofuel generations and also discusses their applications and limitations in agriculture and the environment. In future, researchers should give attention to identifying better strains of algae that produce good-quality biofuel of a high yield, better than economically feasible algal biofuel. Future research is needed to produce a higher amount of product because in recent days, most of the algae face the uneconomical higher costs. Finally, this review paper gives an exposure to a better biofuel in future.

A Review of Nano-Structured Thermites and Explosives: Synthesis and Emerging Applications

Agin P, Ashisha A Aloysius, Dhaneesh K John — Tue, 22 Jul 2025 00:00:00 +0000

Lead-based primary explosives are highly common in the military, mining and pyrotechnics. However, lead is non-biodegradable and poses a serious threat to the environment and living beings. Lead is a potent neurotoxin that causes organ damage and affects cognitive development in humans. It contaminates the air, water and soil, thereby affecting the flora and fauna through bioaccumulation and food chain contamination. It is also notorious for degrading soil fertility and biodiversity. The search for a greener alternative landed on nanostructured materials, fuelling considerable research in this domain. Although their large-scale manufacturing is challenging, these materials promise enhanced performance, safety and reliability over existing systems. The SFE method has been identified as a major breakthrough in facilitating mass-scale manufacturing of such explosive nanoparticles with decent productivity. Coating these nanoparticles with nanothermites resulted in a benign alternative with improved performance over traditional lead-based explosives, called NSTEX. This eliminates the risk of lead contamination while also improving the explosive performance. Despite the success of this system, stabilising these mixtures into operational systems has remained a challenge, hindering its application. A breakthrough in this aspect could be a significant step forward in greener and safer pyrotechnics for the future.

Advancement in Age Estimation in Forensic Science Through Molecular Fingerprinting Techniques – A Review Paper

Ajayakumar A, Kiruthiga U, Arpan Datta Roy — Wed, 13 Aug 2025 00:00:00 +0000

Dactyloscopy has long been used for personal identification from the latent fingerprint residues, capable of providing an insight into various factors of an individual, such as age, sex, habits and lifestyle. Various studies have been conducted to precisely identify the changes in activity of sweat glands and the chemical breakdown of fingerprint residues with respect to time. However, a reliable method for accurately estimating or approximating the age of the fingerprint donor is yet to be established. The emerging field of molecular fingerprinting analyses latent fingerprint sweat residue and profiles the components present in it, which aids in personal identification as an individualistic marker specific to each individual. This review article highlights the advancements in estimating the age of the fingerprint donor from latent fingerprint residue and addresses the technical and technological research gaps in the timeline of molecular fingerprinting techniques, as this method holds potential in aiding forensic investigation and criminal profiling from the fingerprints retrieved from the scene of crime.

Kinetic Studies of Redox reaction between L-tryptophan and oxo-bridged diiron(III,III) complex ion [Fe2(μ-O)(phen)4(H2O)2]4+

Ritam Mukherjee, Piyali Mitra — Sat, 23 Aug 2025 00:00:00 +0000

The title di-iron complex [Fe^III₂(μ-O)(phen)₄(H₂O)₂]⁴⁺(1) (phen= 1,10-phenanthroline) acts a dibasic acid in aqueous media. However, at pH below 1.6, the amounts of its conjugate bases [Fe^III₂(μ-O)(phen)₄(H₂O)(OH)]³⁺(1a) and [Fe^III₂(μ-O)(phen)₄(OH)₂]²⁺(1b) are negligible (pK_a1= 3.71 ± 0.03, pK_a2= 5.28 ± 0.07). In aqueous acidic solutions (pH £1.6), complex 1 is reduced by L-tryptophan to produce [Fe(phen)₃]²⁺ in the presence of externally added phen, following simple first order kinetics. However, at room temperature, the reaction is very slow. With 10 mM tryptophan the reaction takes more than 6 hours to complete. The method of initial rate is used to study the kinetics. The observed rate constants show first-order dependence on the concentrations of both the redox partners. In the pH range of this study, (0.36-1.60) the observed inverse dependence of rate on [H⁺] is attributed to the fact that the singly deprotonated form of the amino acid is the active reductant.

Synthesis, Structural Characterization, and Quantum Chemical Analysis of (E)-2-(1-(4-Bromophenyl)ethylidene)hydrazinecarbothioamide: A Potential Candidate for Biological Applications

R. R. Saravanan, M. Karthika, H. Aafiya Shameem, R. Mendoza Meroño — Tue, 22 Jul 2025 00:00:00 +0000

This study reports the synthesis, structural characterisati- on, and computational analysis of a novel compound, (E)-2-(1-(4-bromophenyl)ethylidene)hydrazine (EBEHC), synthesised via condensation of 1-(4-bromophenyl)ethano ne and thiosemicarbazide in methanol. Yellow single crystals were obtained through recrystallisation. Single-crystal X-ray diffraction revealed that EBEHC crystallises in a monoclinic system (space group P21/c), with a unit cell volume of 1103.56 Å³. Experimental and DFT-calculated geometries showed a strong correlation, with bond length and angle deviations within 0.02 Å and 3°, respectively. Conformational analysis identified R1(a) as the most stable conformer (energy: -9147715.587 kJ/mol), while R2(b) was the least stable (ΔE: +2874.87 kJ/mol). FT-IR and DFT analyses confirmed N–H stretching near 3444 cm⁻¹ and C–Br vibrations near 445 cm⁻¹. Hirshfeld surface analysis revealed significant intermolecular interactions—hydrogen bonding (45.2%) and halogen contacts (19.4%). Molecular docking indicated favourable binding with cholesterol-reducing targets, suggesting potential anti-cholesterol properties. These findings highlight EBEHC’s promising structural, spectroscopic, and biological characteristics for future therapeutic applications.

Synthesis, Characterization, In Silico ADME Profiling, MD Simulations and Unveiling Antibacterial Activities of Novel (E)-5-Amino-3-Styryl-1H-Pyrazole-4-Carbonitrile Derivatives: A Tandem Michael Addition Approach

Sivadharani P., Jayapradha S. R. — Wed, 13 Aug 2025 00:00:00 +0000

An easy and environment benign, time-efficient Tandem Michael addition for the synthesis of (E)-5-amino-3-styryl-1H-pyrazole-4-carbonitrile derivatives using the components of Cinnamaldehyde, hydrazine, and malononitrile through MCR approach have been developed. Using AlCl₃ as a catalyst in aqueous ethanol (1:1) medium, it yields 79–89% of the pyrazole derivative within the period of 30 minutes. The synthesised compounds were investigated for MM2 to predict the molecular behaviour and energy calculation by Chem 3D software, ADME (Adsorption, Distribution, Metabolism and Excretion) properties using Swiss ADME software to profile pharmacokinetic properties of potential drugs, and the compounds' molecular docking (MD) simulations procedure was done with the proteins 4O9I and 2HI9 Hydrolase inhibitors. The protein-ligand interactions between the synthesised compound and the chosen protein revealed antibacterial activity against gram positive and gram negative bacterium, with improved results shows the role of hydrolase inhibitors and their relevance in biological activity. These intriguing findings indicate that the synthesized compounds might be suitable candidates for the development of novel antibacterial drugs in drug discovery.

Insight into Indole Derivatives by Experimental and Theoretical Methods

Vijayalaxmi Mallayya, Srinath, Omnath Patil, Nagesh G. Y., S. M. Hanagodimath — Sat, 09 Aug 2025 00:00:00 +0000

Solvent effect on fluorescence and absorption spectra of fluorescent Indole derivative viz, 5-chloro-3-phenyl-1H-indole-2-carbohydrazide (CPIC), is studied in different solvents at room temperature. The shifts in the position, intensities and shapes of the absorption and fluorescence bands are observed. The ground and excited state dipole moment of the fluorescent molecule are calculated from the Solvatochromic shift method. The excited-state dipole moments were estimated from Lippert, Bakhshiev and Kawski–Chamma–Viallet equations by using the variation of the Stokes’ shift with the solvent dielectric constant and refractive index. The Reichardt’s microscopic solvent polarity parameter is used to calculate the change in dipole moment. It is found that the excited-state dipole moments were higher than those of the ground-state dipole moment. The large value of dipole moment in the excited state is due to the increased polar nature. The HOMO-LUMO energy gap and MEP map are estimated theoretically by using B3LYP/6-31+G (d, p) basis set of the Gaussian 16 program.

Design and Development of a Capacitance Sensor for Gas/Gas or Gas/Liquid Void Fraction Detection

V. Kesavan, J. Jayachandiran, D. Nedumaran — Tue, 22 Jul 2025 00:00:00 +0000

A capacitance-based void fraction sensor was designed to detect a range of liquids and gases. The sensor comprises two semi-concave copper electrodes mounted on a hollow cylindrical glass tube. When a radio frequency signal is applied, variations in the dielectric constant of the surrounding medium cause measurable phase shifts in the signal. Experiments with tap water, distilled water, and ethanol showed that the phase shift is directly correlated with the dielectric constant of the liquid. To study gas-phase behaviour, measurements were carried out under mesoporous conditions (10% liquid and 90% gas flow), allowing characterisation of gas molecules based on their dielectric responses. Signal variations were captured using a digital storage oscilloscope, and the observed phase shifts were compared with theoretical values computed using Mathematica. The experimental findings closely matched the theoretical predictions, validating the sensor’s effectiveness in accurately detecting and monitoring liquid and gas flow in pipelines.

Bounds on Distance Difference Dominating Energy of a Graph

Lincy E., Maheswari V. — Thu, 28 Aug 2025 00:00:00 +0000

This work defines distance difference dominating matrix of graph and estimates characteristic values of distance difference dominating matrix. The summation of absolute eigen/characteristic values of graph's distance difference dominating matrix yields distance difference dominating energy of simple connected graph. The properties of distance difference dominating eigen values are analysed. The boundaries of distance difference dominating energy are established.

Blockchain-Driven Access Control and Data Protection Framework for Industrial IoT Systems

Yashaswini N., Sujatha S. R. — Tue, 22 Jul 2025 00:00:00 +0000

The exponential expansion of Industrial Internet of Things (IIoT) presents major difficulties in guaranteeing strong data security and safe access management over distributed and resource-limited settings. This paper suggests a blockchain-driven architecture combining dynamic access control based on roles with data integrity and confidentiality assurance mechanisms catered for IIoT environments. Three basic levels define the architecture: the IoT layer with intelligent sensors and actuators; the blockchain layer to offer distributed access enforcement and tamper-proof audit trails; and the cloud layer for scalable data storage and processing. Using smart contracts, the system automates access delegation, revocation, and real-time permission changes, hence reducing single points of failure and unwanted access. Compared to centralised systems, experimental evaluation employing Python simulations shows enhanced accuracy, precision, and security at the tradeoff of quite limited throughput. Emphasising privacy, transparency, and resilience, this study provides the basis for reliable, scalable, auditable IIoT infrastructures.