http://nopr.niscpr.res.in/handle/123456789/64207 2026-10-10T21:26:31Z http://nopr.niscpr.res.in/handle/123456789/64217 Title: Ultrasound Assisted Synthesis of Fe Doped TiO2 Nanoparticles for Enhanced Photocatalytic Degradation of Ciprofloxacin Authors: Giram, Dipak; Shrivastava, Tanvi; Das, Arijit Abstract: The present study focused on the photo catalytic degradation of Ciprofloxacin (CP) using ultrasonically synthesized TiO2 and Fe-doped TiO2 (1 wt%) nanoparticles under sunlight. The synthesized nanoparticles were extensively characterized using XRD, FTIR, FESEM and EDS techniques. XRD analysis revealed that Fe+3 ions were successfully incorporated into TiO2, and both TiO2 and Fe-doped TiO2 nanoparticles contained only anatase phase. The average crystallite size of synthesized nanoparticles was estimated to be in the range of 4-6 nm. The EDS analysis has confirmed the existence of Fe in the sample of Fe-doped TiO2. The CP degradation study was performed and compared using synthesized nanoparticles. The optimized value of the degradation was investigated by varying experimental parameters, namely, irradiation time, catalyst dosage, initial CP concentration, and pH. Fe-doped TiO2 nanoparticles outperformed compared to pure TiO2 nanoparticles for CP degradation. The maximum CP degradation was achieved around 87% at a catalyst dosage of 30 mg, initial CP concentration of 10 ppm, pH of 5, and irradiation time of 150 minutes. Page(s): 711-720 2024-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/64216 Title: Rigorous Specification of Vector Timestamp Based Load Sharing Mechanism for Distributed Systems Authors: Yadav, Pooja; Suryavanshi, Raghuraj; Yadav, Divakar Abstract: Distributed systems are autonomous computer nodes or sites that are interconnected by a communication network. These sites function independently without a shared memory or global clock, communicating through message exchanges. Any incoming job can be allocated to any of these independent sites within the system. This leads to a non-uniform distribution of load where some sites become highly loaded while others remain lightly loaded or idle. This scenario leads to poor utilization of resources, heightened response time and impaired system performance. This paper presents the formal specification of a load balancing protocol for distributed systems which is based on vector time-stamping of messages using the vector clock at a site. In order to add fairness to the load sharing mechanism, the request for unburdening the heavily laden site is catered to first whose request message has the least vector timestamp from among the request messages present in the request acquisition queue of the lightly loaded site. Formal methods utilise mathematical techniques to methodically detect and correct errors in the development of software in its initial phases. Event-B is a formal method used to create models of proposed algorithms. The approach used is event-driven, employing set-theoretic principles to construct models of distributed system protocols. The procedure involves creating and satisfying proof obligations to validate the correctness of a model. The article presents a rigorous analysis of the vector clock mechanism in distributed systems as well as a load distribution system which uses vector timestamped messages as the underlying message exchange protocol using Event-B. Page(s): 721-729 2024-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/64215 Title: Impact of RoPP in Wavelength Conversion Inducing Nonlinearity and All-Optical 3R Regeneration for DWDM Networks Authors: Kumar, Chakresh Abstract: The effect of Rotation of Plane of Polarization (RoPP) on wavelength conversion-induced nonlinearity and all-optical 3R regeneration has attracted significant attention in the quickly changing field of Dense Wavelength Division Multiplexing (DWDM) networks, where high-capacity data transmission is critical. This paper explores the complex interactions among RoPP, wavelength conversion, and 3R regeneration, focusing in particular on modeling and assessing the Bit-Error-Rate (BER) and Quality-factor (Q) variations under different polarization rotational angles. In nonlinear media, the 1545 nm Gaussian probe signal interacts with the 1554 nm CW (Continuous Wave) pump signal to cause Cross-Phase Modulation (XPM), which is used to convert wavelengths using nonlinear polarization rotation. Our study presents a theoretical framework that includes RoPP modulation, Variable Optical Attenuators (VOAs), Highly Nonlinear Fiber (HNLF), Clock, and Travelling Wave SOA (TWSOA) as major components to support the possibility of using polarization manipulation to reduce nonlinear impairments and improve network performance as a whole. Using TWSOA integrated 3R regeneration, the results show that the highest/lowest realized quality factor is 28.89/24.54 and the lowest/highest value of Log of (BER) is −179.35/−132.64. It finds out that 3R regeneration improves quality factor by more than 19 at a 90-degree rotational angle, and as a result, BER is significantly decreased. Findings confirm symmetry on both sides with reference to orthogonal polarization. The results of this study open new directions for the development of novel approaches to strategically manipulate the polarization state of light in order to optimize DWDM network performance and overcome the problems of nonlinearities and signal degradation in high-capacity optical communication systems. Page(s): 730-740 2024-07-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/64214 Title: Isolation, Purification, and Characterization of Protease from a Local Bacillus Strain Adapted to Extreme Temperatures in Southern Iraq Authors: Alzobaidy, Hyder Najy; Hasan, Ghasan M; Al-Magsoosi, Suhad K R; Awda, Jasim M Abstract: Bacteria, with their amenability to genetic manipulation and cultivation, represent a favored source of protease enzymes. This study aims to isolate and purify protease from a local Bacillus strain in southern Iraq, known for its resilience to extreme heat. In August 2022, soil samples were collected from Wasit Province, Iraq, and plated on a casein-hydrolyzed medium. Bacillus strains were selected based on microscopic and colony characteristics, with the most active isolate identified as Bacillus subtilis through morphological assessment and 16S rRNA sequencing. Protease production occurred through submerged fermentation, yielding a crude enzyme with enzymatic and specific activities of 241.3 U/mL and 613.3 U/mg, respectively. Partial purification with chilled acetone resulted in an enzyme with enzymatic and specific activities of 935.0 U/mL and 745.0 U/mg, respectively. Further DEAE chromatographic purification showed a single peak of protease activity with increasing sodium chloride ionic strength. The enzyme's specific activity reached 2491.8 U/mg, with a recovery rate of nearly 90%. Subsequent gel column filtration via 1.5 × 60 cm Sephadex G-100 displayed a single peak of protease activity and increased specific activity (4264.10 U/mg) with a 73% recovery rate. Molecular weight determination using Sephadex G-100 column indicated a size of 29.3 kDa for the B. subtilis protease. Regarding thermal stability, the enzyme demonstrated initial stability at 60°C, but prolonged exposure reduced activity. In contrast, exposure to 70°C and 80°C resulted in rapid declines in enzymatic activity. This study highlights the isolation and purification of a robust protease enzyme from a local Bacillus strain, underscoring its potential significance in various industrial applications. Page(s): 741-747 2024-07-01T00:00:00Z