Optimization of DWDM Demultiplexer Using Regression Analysis

We propose a novel twelve-channel Dense Wavelength Division Multiplexing (DWDM) demultiplexer, using the two-dimensional photonic crystal (2D PC) with square resonant cavity (SRC) of ITU-T G.694.1 standard. The DWDM demultiplexer consists of an input waveguide, SRC, and output waveguide. The SRC in the proposed demultiplexer consists of square resonator and microcavity. The microcavity center rod radius (Rm) is proportional to refractive index. The refractive index property of the rods filters the wavelengths of odd and even channels. The proposed microcavity can filter twelve ITU-T G.694.1 standard wavelengths with 0.2 nm/25 GHz channel spacing between the wavelengths. From the simulation, we optimize the rod radius and wavelength with linear regression analysis. From the regression analysis, we can achieve 95% of accuracy with an average quality factor of 7890, the uniform spectral line-width of 0.2 nm, the transmission efficiency of 90%, crosstalk of −42 dB, and footprint of about 784 μm2

RECENT DEVELOPMENTS IN NATURAL FIBER HYBRID COMPOSITES FOR BALLISTIC APPLICATIONS: A COMPREHENSIVE REVIEW OF MECHANISMS AND FAILURE CRITERIA

The use of lightweight natural fiber functional composites in the manufacturing of ballistic protective materials has garnered significant attention in recent years. This is due to their superior mechanical properties, cost-effectiveness, and environmental sustainability. Ballistic panels are constructed using multiple layers of diverse composites, which collectively exhibit excellent mechanical properties. These properties enable them to withstand strong impacts enhancing their capability for different applications in defense, military, and aerospace components. The primary focus of this review is to examine the different influential factors that govern the development of novel polymeric materials for current ballistic applications. It also explores various research approaches, such as experimental, analytical, numerical modeling, and empirical techniques. The review highlights both internal factors, such as material composition, and external factors, such as projectile parameters (e.g., nose angles, projectile shape, and projectile size). These factors are crucial for optimizing the robust ballistic performance of natural fiber-based polymer composites. In addition, various valuable insights to develop more effective and sustainable ballistic protective materials for applications in bulletproof helmets, defense, aerospace, and military sectors have also been elaborated. Consequently, the article presents a comprehensive review of the impact of utilizing various natural fibers as alternative materials to Kevlar for armor structures, offering a state-of-the-art perspective and challenges faced in full-scale implementation

Synthesis, spectral correlation analysis and evaluation of biological activities of some substituted hydrazones

Some novel substituted hydrazone derivatives of amino guanidine have been synthesized with different substituted benzaldehydes by condensation method. The synthesized hydrazones were characterized by their physical constants, UV, IR and NMR spectra. The spectral data have been correlated with Hammett substituent constants and Swain–Lupton parameters. From the result of statistical analysis, the effects of substituents on the spectral data have been predicted. The antimicrobial activities of these synthesized hydrazone compounds have been screened by Bauer-Kirby method using human pathogenic bacteria and fungal species. The antimicrobial activities of all synthesized hydrazone compounds have shown significant activity

Synthesis, Evaluation of Substituent Effect and Antimicrobial Activities of Substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-one Compounds

A series of ten substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-one compounds were synthesized by Crossed-Aldol condensation of 3-bromo-4-marpholino acetophenone with various substituted and unsubstituted benzaldehydes in presence of sodium hydroxide. The entire ten compounds are novel and these have been newly synthesized compounds. The synthesized substituted 3-phenylprop-2-en-1-one were characterized by their physical constants and UV, IR, NMR spectral data. These observed UV absorption maximum (λmax nm) value. The group frequencies of infrared absorption (cm-1) of νCO s-cis and s-trans, deformation modes of νCH out of plane and in-plane, νCH=CH out of plane, ν>C=C<out of plane values, 1H chemical shifts (ppm) vinyl protons, 13C chemical shifts (ppm) carbonyl carbons and vinyl carbons values were correlated with various Hammett substituent constants, and Swain-Lupton parameters using single and multi-regression analyses. From the results of statistical analysis, the effects of substituents on the functional group frequencies were studied. The antimicrobial activities of these synthesized substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-ones have been screened using Kirby-Bauer method. DOI: http://dx.doi.org/10.17807/orbital.v9i1.85

Eco-friendly Synthesis, Spectral Correlation Analysis, and Antimicrobial Activities of Substituted (E)-1-benzylidene-2-(3-nitrophenyl)hydrazines

In the present study, a series of ten substituted (E)-1-benzylidene-2-(3-nitrophenyl)hydrazine compounds have been synthesized by condensation of  3-nitrophenylhydrazine with various substituted benzaldehydes using SiO2-H3PO4 catalyst under solvent free condition. This method involves shorter reaction time (5-10 minutes) with excellent yield (80-90%). The structures of the synthesized (E)-1-benzylidene-2-(3-nitrophenyl)hydrazines have been characterized by their physical constants, UV, FT-IR and NMR spectral data. The characterized UV, FT-IR and NMR spectral data have been correlated with Hammett constants using single-linear and multi-linear regression analysis. From the results of single-linear and multi-linear regression analysis the effect of substituents on the spectral data have been discussed.  The antimicrobial activities of all the (E)-1-benzylidene-2-(3-nitrophenyl)hydrazine compounds have been tested using Bauer-Kirby method. DOI: http://dx.doi.org/10.17807/orbital.v8i5.86

Synthesis, Evaluation of Substituent Effect and Antimicrobial Activities of Substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-one Compounds

A series of ten substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-one compounds were synthesized by Crossed-Aldol condensation of 3-bromo-4-marpholino acetophenone with various substituted and unsubstituted benzaldehydes in presence of sodium hydroxide. The entire ten compounds are novel and these have been newly synthesized compounds. The synthesized substituted 3-phenylprop-2-en-1-one were characterized by their physical constants and UV, IR, NMR spectral data. These observed UV absorption maximum (λmax nm) value. The group frequencies of infrared absorption (cm-1) of νCO s-cis and s-trans, deformation modes of νCH out of plane and in-plane, νCH=CH out of plane, ν>C=C<out of plane values, 1H chemical shifts (ppm) vinyl protons, 13C chemical shifts (ppm) carbonyl carbons and vinyl carbons values were correlated with various Hammett substituent constants, and Swain-Lupton parameters using single and multi-regression analyses. From the results of statistical analysis, the effects of substituents on the functional group frequencies were studied. The antimicrobial activities of these synthesized substituted (E)-1-(3-bromo-4-morpholinophenyl)-3-phenylprop-2-en-1-ones have been screened using Kirby-Bauer method. DOI: http://dx.doi.org/10.17807/orbital.v9i1.85

Synthesis, spectral LFER and antimicrobial activities of some (E)-N׳-(1-(substituted phenyl)ethylidene)benzohydrazides

About eleven substituted (E)-N׳-(1-(substituted phenyl) ethylidene) benzo- hydrazides have been synthesized. They are characterized by their analytical, ultraviolet, infrared and NMR spectral data. The antibacterial and fungal activities of these chalcones have been evaluated

Divergent evolution of Corynebacterium diphtheriae in India: An update from National Diphtheria Surveillance network.

Diphtheria is caused by a toxigenic bacterium Corynebacterium diphtheria which is being an emerging pathogen in India. Since diphtheria morbidity and mortality continues to be high in the country, the present study aimed to study the molecular epidemiology of C. diphtheriae strains from India. A total of 441 diphtheria suspected specimens collected as part of the surveillance programme between 2015 and 2020 were studied. All the isolates were confirmed as C. diphtheriae with standard biochemical tests, ELEK's test, and real-time PCR. Antimicrobial susceptibility testing for the subset of isolates showed intermediate susceptibility to penicillin and complete susceptible to erythromycin and cefotaxime. Isolates were characterized using multi locus sequence typing method. MLST analysis for the 216 C. diphtheriae isolates revealed major diversity among the sequence types. A total of 34 STs were assigned with majority of the isolates belonged to ST466 (30%). The second most common ST identified was ST405 that was present in 14% of the isolates. The international clone ST50 was also seen. The identified STs were grouped into 8 different clonal complexes (CC). The majority belongs to CC5 followed by CC466, CC574 and CC209, however a single non-toxigenic strain belongs to CC42. This epidemiological analysis revealed the emergence of novel STs and the clones with better dissemination properties. This study has also provided information on the circulating strains of C. diphtheriae among the different regions of India. The molecular data generated through surveillance system can be utilized for further actions in concern

Antiulcer, wound healing and hepatoprotective activities of the seaweeds Gracilaria crassa, Turbinaria ornata and Laurencia papillosa from the southeast coast of India

Seaweeds have bioactive compounds of interest in the pharmaceutical industry. In India, seaweeds are used exclusively for phycocolloids production and have not yet received consideration as a dietary supplement. So, it has become imperative to explore the biomedical potential of seaweeds and promote their utilization as a functional food. The seaweeds Turbinaria ornata, Gracillaria crassa and Laurencia papillosa, collected from the Tuticorin coast of the Southeast coast of India and selected based on preliminary screening, were extracted with acetone and evaluated for antiulcer, wound healing and hepatoprotective activities. L. papillosa showed the highest level of gastric protection activity (81%) at 200 mg/kg, comparable to the standard drug ranitidine (90%). G. crassa followed with 76%. G. crassa and L. papillosa, showed marked wound-healing activity. G. crassa at 200 mg/kg, showed a marked effect on the serum marker enzymes indicating prominent hepatoprotective activity. The noteworthy wound-healing and hepato-protective properties of G. crassa besides anti-ulcer activity next to L. papillosa were indicative of its potential for further consideration