1. Nitroreductase-sensitive fluorescent covalent organic framework for tumor hypoxia imaging in cellsTina Skorjanc, Dinesh Shetty, Sushil Kumar, Damjan Makuc, Gregor Mali, Janez Vovavšek, Martina Bergant Marušič, Matjaz Valant, 2023, original scientific article Keywords: covalent organic frameworks, imaging, hypoxia, fluorescence, cancer cells Published in RUNG: 17.05.2023; Views: 111; Downloads: 5
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3. Hydrophobicity Tuning in Isostructural Urchin-Shaped Covalent Organic Framework Nanoparticles by Pore Surface Engineering for Oil–Water SeparationGobinda Das, Tina Skorjanc, Thirumurugan Prakasam, Bikash Garai, Salma Abubakar, Christina Zalch Saad, Felipe Gandara, Renu Pasricha, Sudhir Kumar Sharma, Sabu Varghese, Ramesh Jagannathan, Mark A. Olson, Ali Trabolsi, 2022, original scientific article Keywords: Adsorption, Covalent organic frameworks, Hydrophobicity, Lipids, Materials Published in RUNG: 26.09.2022; Views: 461; Downloads: 0 This document has many files! More... |
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5. Speckle interferometric investigation of argon pressure-induced surface roughness modifications in RF-sputtered MoO[sub]3 filmS. Soumya, R. Arun Kumar, S. Sreejyothi, Vimal Raj, Mohanachandran Nair Sindhu Swapna, Sankaranarayana Iyer Sankararaman, 2021, original scientific article Abstract: Film quality analysis is of more considerable signifcance due to its diversifed applications in various felds of technology.
The present work reports the speckle interferometric analysis of the argon pressure-induced surface roughness modifcations
of RF sputtered MoO3 flms. The paper suggests a new method of surface quality analysis of thin flms through a parameter
δ, which is the diference between the initial and fnal inertia moment values in the study of the thermal-induced dynamic
speckle pattern. The limitations of root mean square surface roughness analysis of the atomic force microscopic image of the
flms is also exemplifed. The research suggests that argon pressure plays a vital role in the surface property of RF sputtered
flms and also that the dynamic speckle analysis can give precise information about the quality of flms. The contour plot of
particle displacement vector under thermal stress, suggests the degree of uniformity in the distribution of particles in the flm. Keywords: speckle pattern interferometry, time history of speckle pattern, cross correlation, inertia moment Published in RUNG: 04.07.2022; Views: 498; Downloads: 0 This document has many files! More... |
6. Weathering induced morphological modification on the thermal diffusivity of natural pyrrhotite : a thermal lens studyMohanachandran Nair Sindhu Swapna, V. Gokul, Vimal Raj, R. Manu Raj, S. N. Kumar, Sankaranarayana Iyer Sankararaman, 2021, original scientific article Abstract: Natural pyrrhotites have gained significant attention due to
their interesting electronic, antimicrobial, and chemical
properties. The present work attempts to explore the
morphology-induced modifications in the thermal
characteristics of natural pyrrhotite due to ageing. The
morphological, elemental, structure, optical, and thermal
characterisations help in understanding the effect of
ageing. The effects of five years of ageing of the sample
are (i) Field Emission Scanning Electron Microscopic
analysis reveals a morphological transformation from flakes
to agglomerated powder, (ii) elemental analyses suggest
the ageing induced compositional modification (iii) the
Tauc plot analysis shows a bandgap energy modification
from 1.46 eV to 1.92 eV, (iv) X-ray Diffraction (XRD), Fourier
Transform Infrared, and X-ray photoelectron spectroscopic
studies affirm the formation of oxy-hydroxides (v) the XRD
data indicates an increase of dislocation density, and (vi)
Photoluminescence study shows a deep violet emission
evidenced through the CIE plot. The study by the thermal
lens technique shows a lowering of thermal diffusivity
study by 23%, due to the morphological modifications,
adsorbed/chemisorbed hydroxyl groups, and the formation
of secondary compounds due to oxidation and weathering.
The phonon boundary scattering, weathering induced
smaller grain size, reduced phonon mean free path, and
point defects also account for the lowering of the thermal
diffusivity value and thereby influencing its properties. Keywords: pyrrhotite, thermal diffusivity, thermal lens, ageing, morphology Published in RUNG: 30.06.2022; Views: 502; Downloads: 3
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7. Downscaling of sample entropy of nanofluids by carbon allotropes : a thermal lens studyMohanachandran Nair Sindhu Swapna, Vimal Raj, S. Sreejyothi, K. Satheesh Kumar, Sankaranarayana Iyer Sankararaman, 2020, original scientific article Abstract: The work reported in this paper is the first attempt to delineate the molecular or particle dynamics from the thermal lens signal of carbon allotropic nanofluids (CANs), employing time series and fractal analyses. The nanofluids of multi-walled carbon nanotubes and graphene are prepared in base fluid, coconut oil, at low volume fraction and are subjected to thermal lens study. We have studied the thermal diffusivity and refractive index variations of the medium by analyzing the thermal lens (TL) signal. By segmenting the TL signal, the complex dynamics
involved during its evolution is investigated through the phase portrait, fractal dimension, Hurst exponent, and sample entropy using time series and fractal analyses. The study also explains how the increase of the photothermal energy turns a system into stochastic and anti-persistent. The sample entropy (S) and refractive index analyses of the TL signal by segmenting into five regions reveal the evolution of S with the increase of enthalpy. The lowering of S in CAN along with its thermal diffusivity (50%–57% below) as a result of heat-trapping suggests
the technique of downscaling sample entropy of the base fluid using carbon allotropes and thereby opening a novel method of improving the efficiency of thermal systems. Keywords: carbon allotropic nanofluids, time series, entropy, MWCNT, thermal lens signal Published in RUNG: 30.06.2022; Views: 500; Downloads: 0 This document has many files! More... |
8. Soot effected sample entropy minimization in nanofluid for thermal system design : a thermal lens studyMohanachandran Nair Sindhu Swapna, Vimal Raj, K. Satheesh Kumar, Sankaranarayana Iyer Sankararaman, 2020, original scientific article Abstract: The present work suggests a method of improving the thermal system efficiency, through entropy minimisation,
and unveils the mechanism involved by analysing the molecular/particle dynamics in soot nanofluids (SNFs)
using the time series, power spectrum, and wavelet analyses of the thermal lens signal (TLS). The photothermal
energy deposition in the SNF lowers the refractive index due to the temperature rise. It triggers the particle dynamics that are investigated by segmenting the TLS and analysing the refractive index, phase portrait, fractal dimension (D), Hurst exponent (H), and sample entropy (SampEn). The wavelet analysis gives information about
the relation between the entropy and the frequency components. When the phase portrait analysis reflects the
complex dynamics from region 1 to 2 for all the samples, the SampEn analysis supports it. The decreasing
value of D (from 1.59 of the base fluid to 1.55 and 1.52) and the SampEn (from 1.11 of the base fluid to 0.385
and 0.699) with the incorporation of diesel and camphor soot, indicate its ability to lower the complexity, randomness, and entropy. The increase of SampEn with photothermal energy deposition suggests its relation to
the thermodynamic entropy (S). The lowering of thermal diffusivity value of the base fluid from
1.4 × 10−7 m2/s to 1.1 × 10−7 and 0.5 × 10−7 m2
/s upon diesel and camphor soot incorporation suggests the
heat-trapping and reduced molecular dynamics in heat dissipation. Keywords: soot, entropy, thermal system, photothermal, time series, nanofluid, fractal Published in RUNG: 30.06.2022; Views: 516; Downloads: 0 This document has many files! More... |
9. Development of prototype of electronic speckle interferometry based spirometerSwapna Mohanachandran Nair Sindhu, KUMAR ARUN, KUMAR SUNIL, SREEJYOTHI S, RAJ VIMAL, SANKARARAMAN SANKARANARAYANA IYER, 2021, original scientific article Abstract: The paper reports the design, construction, and calibration of the prototype of a spirometer based on electronic
speckle interferometry (ESPI). The conventional ESPI setup is modified by incorporating a DNM (Diaphragm-Nozzle-Mouthpiece) module comprising a metallic diaphragm, regulated airflow channel, and a mouthpiece. The
exhaled air after a deep breathe is channelled to the DNM module where the diaphragm gets deformed. From the
circular fringe pattern obtained by subtracting the speckled images before and after deformation of the metallic
diaphragm, the radius of curvature (R) due to deformation is calculated using the principle of Newton’s rings.
The value of R and peak expiratory flow rate (PEFR) from the standard spirometer reading are correlated. From
the 640 observations spread over the range 100 - 500 L/min in the standard spirometer, an empirical relation
is set in terms of R from the scatter plot. The ESPI spirometer (ESPIS) is validated by determining the value of
R corresponding to a particular PEFR from the empirical relation and also from the standard spirometer. The
PEFR calculated from ESPIS matches well with the standard spirometer reading, which suggests that the system
designed and constructed can be used for biomedical applications for assessing lungs’ efficiency. Keywords: Speckle, Spirometer, DNM module, ESPIS, Peak expiratory flow rate Published in RUNG: 28.06.2022; Views: 499; Downloads: 0 This document has many files! More... |
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