St. Xavier`s College, Mapusa, Bardez Goa

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Recent Submissions

Improving hemoglobin estimation accuracy through standardizing of light-emitting diod epower
(International Journal of Electrical and Computer Engineering, 2022-02-01) Caje Francis Pinto; Jivan Shrikrishna Parab; Marlon Darius Sequeira; Gourish Naik
Nowadays, hemoglobin monitoring is essential during surgeries, blood donations, and dialysis. Which are normally done using invasive methods. To monitor hemoglobin, a non -invasive hemoglobin meter was developed with five fixed light-emitting diode (LED) wavelengths at 670 nm, 770 nm, 810 nm, 850 nm, 950 nm and controlled using an Arduino Uno embedded development board. A photodetector with an on-chip trans-impedance amplifier was utilized to acquire the transmitted signal through the finger using the photoplethysmography (PPG) principle. Before the standardization of LED power, we had tested the designed system on fifteen subjects for the five wavelengths and estimated the hemoglobin with an accuracy of 96.51% and root mean square error (RMSE) of 0.57 gm/dL. To further improve the accuracy, the LED power was standardized and the PPG signal was reacquired on the same subjects. With this, the accuracy improved to 98.29% and also reduced the RMSE to 0.36 gm/dL. The designed system with LED power standardization showed a good agreement with pathology results with the coefficient of determination R2=0.981. Also, Bland–Altman analysis was used to evaluate the designed system and it showed good agreement between the two measurements.
Green Synthesis of Copper Oxide Nanoparticles Using Coffee, Piper Nigrum, AND CoriandrumSativum and Its Application in Photocatalytic Degradation Of Methylene Blue Dye
(Rasayan Journal of Chemistry (EBSCO), 2023-01-01) Mandrekar, Pratiksha P.; DSouza, Andrew
This study focuses on the green synthesis of nanoparticles and its utilization in the development of nanotechnology for promoting environmental sustainability. Copper Oxide nanoparticles are synthesized using plant extracts of Coffee, Piper Nigrum, and Coriandrum Sativum containing bio-components acting as reducing agents to reduce 1M Copper Sulphate (CuSO4.5H2O) solution., for further formation of Copper Oxide nanoparticles. Instrumental techniques were adopted to characterize the synthesized Copper Oxide nanoparticles, Viz. UV-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). These biosynthesized Copper Oxide nanoparticles were employed as catalysts for the photocatalytic degradation of Methylene blue dye, resulting in a very effective and feasible photocatalyst.
NiWO4 catalyzed expeditious synthesis of Pyranopyrazoles
(Indian Journal of Chemistry (NICPR), 2023-03-09) Mesira Godinhoa; Lalitprabha N Salgaonkarb; Tushar S Anvekarc,; Teotone Vazc; Hari K Kadam
In this paper, a multicomponent green rapid method for synthesis of pyranopyrazoles is reported using NiWO4 in water in 15 min. Environment friendly features such as energy efficiency, aqueous medium, no hazardous solvent, no chromatography, in addition to the short reaction time, catalyst reusability and substrate tolerance without affecting yield proves the near perfectness of this method for synthesis of medicinally important pyranopyrazoles. NiWO4, ZnWO₄, and CuWO₄ have been synthesized using extract of plant Phyllantus amarus. The prepared catalysts have been characterized byXRD, EDX and SEM.
Structure of water in polyvinylalcohol based ferrogel: effect of carbonyl iron concentration
(Journal of Polymer Research (Springer Nature Link), 2023-02-02) Mathias B. Lawrence; Rekha Rao
Three PVA-borax ferrogels with micron-sized carbonyl iron particles (as the magnetically-sensitive dopant) have been synthesized, alongwith a similar undoped hydrogel. The structural arrangement of the solvent (water) molecules has been studied, as a function of carbonyl iron concentration, using X-ray Diffraction (XRD) and, Raman and Fourier Transform Infra-red (FT-IR) spectroscopy. The presence and concentration of the dopant particles leads to significant changes in the water content and structural arrangement of the solvent molecules within the matrices. Increase in the concentration of the magnetic dopant causes decrease in the number of water molecules possessing average size and average inter-molecular distance. The decrease of the two parameters is unequal leading to a non-monotonic behaviour of the relative ratio of the number of molecules having average inter-molecular spacing of water to those possessing average molecular size. De-convoluted Raman spectra show relative changes in the intensities of the four O-H stretching modes of water. The dopant concentration is found to affect the number density of the bound and un-bound water molecules within the ferrogel matrices. The observed structural arrangement of the solvent molecules is explained on the basis of changes in pore size and re-arrangement of water owing to the presence and concentration of the dopant particles within the pores of the ferrogel polymer network.
Influence of cross-linker concentration on the water contained within the pores of poly(vinyl alcohol)-borax hydrogels: a vibrational spectroscopic study
(Polymer Bulletin (Springer Nature Link), 2024-07-14) Mathias B. Lawrence
The water content and solvent structure of six poly(vinyl alcohol)-based hydrogels possessing different proportions of borax have been studied as a function of cross-linker concentration. The differing proportions of borax in the matrices cause mesoscopic structural changes in the polymer hydrogel network which lead to differences in water content. The FTIR data show non-monotonic variations in the intensities of the various bands. For the Raman data, the region sensitive to the OH vibrations has been fitted with four Gaussian peaks corresponding to the stretching modes of liquid water. The wavenumber positions of the peaks are dependent on the water content. The non-monotonic behavior of the peak parameters suggests that the structure of entrapped water molecules is dependent on the local mesoscopic structure. From the measurements, cross-linker proportions are seen to affect, both, polymer network and the solvent.