Advanced Cell Culture Technology for Essential Oil Production and Microarray Studies Leading to Discovery of Genes for Fragrance Compounds in Michelia alba (Cempaka putih)

Rusli Bin Ibrahim,Sobri Bin Hussein,Musaalbakri Bin Abdul Manan,Hazniza Binti Adnan,Maheswary Vellupillai 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

1P-754 Synthesis and Characterization of Dual Doped Nb₂O₅ Inverse Opal Phetoelectrodes for Photoelectrochemical Water Splitting

( Maheswari ),강순형 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

Organic <i>Datura metel</i> Leaf Extract Mediated Inorganic Rare Earth La₂O₃ Nanocrystals Formation

Maheswari, R. Uma,Yuvakkumar, R,Ravi, G,Hong, S. I American Scientific Publishers 2019 Journal of nanoscience and nanotechnology Vol.19 No.7

Structural and spectroscopic properties of γ-ray irradiated Er³⁺-doped lead phosphate glasses

Maheswari, T.,Basavapoornima, Ch.,Linganna, K.,Ju, S.,Han, W.-T.,Jayasankar, C.K. Elsevier 2018 Journal of luminescence Vol.203 No.-

<P><B>Abstract</B></P> <P>Structural and spectroscopic properties of varying concentrations of Er<SUP>3+</SUP> ion in P<SUB>2</SUB>O<SUB>5</SUB>- PbO-K<SUB>2</SUB>O-Al<SUB>2</SUB>O<SUB>3</SUB>-Na<SUB>2</SUB>O (PPbKANEr) glasses were studied before and after consecutive γ-ray irradiation. FTIR spectra of all the contemplated glasses confirm the presence of characteristic vibrational bands mainly because of phosphate groups. The optical absorption spectra of Er<SUB>2</SUB>O<SUB>3</SUB>-doped glasses are more stable and do not exhibit any variations after γ-ray irradiation particularly when Er<SUP>3+</SUP> ions are present in higher concentrations. Judd-Ofelt (JO) analysis was carried out for γ-ray irradiated glasses and the resultant three phenomenological intensity parameters were found to be Ω<SUB>2</SUB> = 1.98, Ω<SUB>4</SUB> = 0.78 and Ω<SUB>6</SUB> = 1.24 (×10<SUP>–20</SUP> cm<SUP>2</SUP>). A bright emission corresponding to <SUP>4</SUP>S<SUB>3/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB> transition in the green region was observed with the excitation of 379 nm. Broad luminescence peak at 1535 nm (<SUP>4</SUP>I<SUB>13/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB>) are observed in the region of 1400–1700 nm with the excitation of 980 nm. The important spectroscopic properties such as absorption (σ<SUB>abs</SUB>(λ)) and emission cross-sections (σ<SUB>emi</SUB>(λ)), gain band width (FWHM × σ<SUB>emi</SUB>(λ)) for <SUP>4</SUP>I<SUB>13/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB> transition at 1.53 µm were assessed for γ-ray irradiated PPbKANEr1.0 glass and the values found to be 6.73 × 10<SUP>–21</SUP> cm<SUP>2</SUP>, 7.33 × 10<SUP>–21</SUP> cm<SUP>2</SUP> and 264 × 10<SUP>–28</SUP> (cm<SUP>3</SUP>), respectively. The decay curves for the <SUP>4</SUP>I<SUB>13/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB> transition of the γ-ray irradiated PPbKANEr glasses exhibit exponential nature and the lifetimes found to be decreased (3.72–0.62 ms) with the increasing Er<SUB>2</SUB>O<SUB>3</SUB> concentration (0.05–4.0 mol%). The upconversion luminescence spectra exhibit two emissions at 525 nm (<SUP>2</SUP>H<SUB>11/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB>) and 543 nm (<SUP>4</SUP>S<SUB>3/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB>) in the green region along with a fairly feeble red emission at around 650 nm (<SUP>4</SUP>F<SUB>9/2</SUB> → <SUP>4</SUP>I<SUB>15/2</SUB>).</P> <P><B>Graphical abstract</B></P> <P>Comparison of the fluorescence decay of the <SUP>4</SUP>S<SUB>3/2</SUB> level for γ-ray irradiated leadphosphate glass doped with 1.0 mol% of Er<SUB>2</SUB>O<SUB>3</SUB>.</P> <P>[DISPLAY OMISSION]</P>

Partial Discharge Signal Denoising using Adaptive Translation Invariant Wavelet Transform-Online Measurement

Maheswari, R.V.,Subburaj, P.,Vigneshwaran, B.,Iruthayarajan, M. Willjuice The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

Partial discharge (PD) measurements have emerged as a dominant investigative tool for condition monitoring of insulation in high voltage equipment. But the major problem behind them the PD signal is severely polluted by several noises like White noise, Random noise, Discrete Spectral Interferences (DSI) and the challenge lies with removing these noise from the onsite PD data effectively which leads to preserving the signal for feature extraction. Accordingly the paper is mainly classified into two parts. In first part the PD signal is artificially simulated and mixed with white noise. In second part the PD is measured then it is subjected to the proposed denoising techniques namely Translation Invariant Wavelet Transform (TIWT). The proposed TIWT method remains the edge of the original signal efficiently. Additionally TIWT based denoising is used to suppress Pseudo Gibbs phenomenon. In this paper an attempt has been made to review the methodology of denoising the PD signals and shows that the proposed denoising method results are better when compared to other wavelet-based approaches like Fast Fourier Transform (FFT), Discrete Wavelet Transform (DWT), by evaluating five different parameters like, Signal to noise ratio, Cross-correlation coefficient, Pulse amplitude distortion, Mean square error, Reduction in noise level.

염료감응형 태양전지로의 응용을 위한 얇은 TiO2가 코팅 된 WO3 역오팔 광전극의 개발

Maheswari Arunachalam,곽서의,이인호,김청수,강순형,이상권 한국재료학회 2019 한국재료학회지 Vol.29 No.8

In this study, we prepare pure WO3 inverse opal(IO) film with a thickness of approximately 3 μm by electrodeposition, and an ultra-thin TiO2 layer having a thickness of 2 nm is deposited on WO3 IO film by atomic layer deposition. Both sets of photoelectrochemical properties are evaluated after developing dye-sensitized solar cells(DSSCs). In addition, morphological, crystalline and optical properties of the developed films are evaluated through field-emission scanning electron microscopy(FE-SEM), High-resolution transmission electron microscopy(HR-TEM), X-ray diffraction(XRD) and UV/ visible/infrared spectrophotometry. In particular, pure WO3 IO based DSSCs show low VOC, JSC and fill factor of 0.25 V, 0.89 mA/cm2 and 18.9 %, achieving an efficiency of 0.04 %, whereas the TiO2/WO3 IO based DSSCs exhibit VOC, JSC and fill factor of 0.57 V, 1.18 mA/cm2 and 50.1 %, revealing an overall conversion efficiency of 0.34 %, probably attributable to the high dye adsorption and suppressed charge recombination reaction.

Air pollution enhances susceptibility to novel coronavirus (COVID-19) infection - an impact study

S. Maheswari,Rajarajan Pethannan,Shanthi Sabarimurugan 환경독성보건학회 2020 환경독성보건학회지 Vol.35 No.4

On concurring to the current evidence, the myriad of vulnerable COVID-19 (Coronavirus Disease 19) transmission is acquiring through human-to-human transmission through droplets, which is depicting devastating pandemic. Urbanization and industrialization are the major contributing factors to the on-going change in global climate, with increased air pollution and poor air quality. As the global climate and air quality deteriorate, air pollutants remain as a fundamental concern to public health. Air pollution has been globally acknowledged as a major influence and exacerbating factor for human morbidity and mortality influenced on various respiratory diseases such as lung cancer, bronchitis, chronic obstructive pulmonary diseases, pneumonia, asthma, and influenza. Patients by long – term exposure to polluted air leads to chronic lung and heart conditions are less able to fight off lung infections and likely to die. Polluted air in developed countries is causing heart and lung damage and is responsible for early deaths in a year. This is also likely the case for COVID-19. The more severe impact by COVID-19 on city dwellers and those exposed to toxic fumes leads to the primary health damage such as respiratory infections than on others. The health damage inflicted on people by long-standing air pollution in cities is likely to increase the death rate by COVID-19. By lowering air pollution levels probability to reduce the spread of most vulnerable viruses by aerosol to fight against any possible future pandemics.

Video of World Festivals as Novelties in Teaching Description Writing Using a Genre-Based Approach

( Uma Maheswari Rajagopalan ) 범태평양응용언어학회 2017 범태평양응용언어학회지 Vol.21 No.1

In order to motivate ESL students and engage them in different tasks effectively, it is necessary to make the tasks novel to the students. As one possible way of introducing novelty in the course, films could be used advantageously. In this study, a writing course integrated with videos of movies and cultural festival of different regions of the world including that of author`s country were used as a novel activity and students` attitudes were investigated through questionnaire and open-ended comments. The students belonged to second year undergraduate course of food and nutrition sciences of a Japanese private university. In addition to the film videos as part of listening activity, students were introduced to writings of different genres such as autobiographical, general description, procedure and argumentative writings using a genre-based approach. Students were first introduced to a model writing followed by deconstructing the model writing based on a set of questions. Next, students were asked to write based on the questions to make an outline of their own writings. Following making an outline in the classroom, students constructed their own one paragraph essays. Effects of learning were assessed through students` engagement in writing and in class questionnaire on the video. It was found that students showed real interest in watching film and cultural festivals videos. With cultural festivals, students were made to make comparison with their own and report describing the interesting feature of the festival. The students were also asked to critically reflect on the festivals themselves. Because of the novelty, students actively engaged in the class making the class interesting to the students. In future, a more detailed curriculum using festivals from different parts of their country along with festivals from different parts of the world could be worth considering.

Effects of Al₂O₃ Coating on BiVO₄ and Mo-doped BiVO₄ Film for Solar Water Oxidation

Arunachalam, Maheswari,Yun, Gun,Lee, Hyo Seok,Ahn, Kwang-Soon,Heo, Jaeyeong,Kang, Soon Hyung The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.4

Planar BiVO₄ and 3 wt% Mo-doped BiVO₄ (abbreviated as Mo:BiVO₄) film were prepared by the facile spin-coating method on fluorine doped SnO₂(FTO) substrate in the same precursor solution including the Mo precursor in Mo:BiVO₄ film. After annealing at a high temperature of 450℃ for 30 min to improve crystallinity, the films exhibited the monoclinic crystalline phase and nanoporous architecture. Both films showed no remarkably discrepancy in crystalline or morphological properties. To investigate the effect of surface passivation exploring the Al₂O₃ layer, the ultra-thin Al₂O₃ layer with a thickness of approximately 2 nm was deposited on BiVO₄ film using the atomic layer deposition (ALD) method. No distinct morphological modification was observed for all prepared BiVO₄ and Mo:BiVO₄ films. Only slightly reduced nanopores were observed. Although both samples showed some reduction of light absorption in the visible wavelength after coating of Al₂O₃ layer, the Al₂O₃ coated BiVO₄ (Al₂O₃/BiVO₄) film exhibited enhanced photoelectrochemical performance in 0.5 M Na₂SO₄ solution (pH 6.5), having higher photocurrent density (0.91 mA/㎠ at 1.23 V vs. reversible hydrogen electrode (RHE), briefly abbreviated as V_RHE) than BiVO₄ film (0.12 mA/㎠ at 1.23 V_RHE). Moreover, Al₂O₃ coating on the Mo:BiVO₄ film exhibited more enhanced photocurrent density (1.5 mA/㎠ at 1.23 V_RHE) than the Mo:BiVO₄ film (0.86 mA/㎠ at 1.23 V_RHE). To examine the reasons, capacitance measurement and Mott-Schottky analysis were conducted, revealing that the significant degradation of capacitance value was observed in both BiVO₄ film and Al₂O₃/Mo:BiVO₄ film, probably due to degraded capacitance by surface passivation. Furthermore, the flat-band potential (V_FB) was negatively shifted to about 200 mV while the electronic conductivities were enhanced by Al₂O₃ coating in both samples, contributing to the advancement of PEC performance by ultra-thin Al₂O₃ layer.

Unique photoelectrochemical behavior of TiO₂ nanorods wrapped with novel titanium Oxy-Nitride (TiO_xN_y) nanoparticles

Arunachalam, Maheswari,Yun, Gun,Ahn, Kwang-Soon,Seo, Won-Seon,Jung, Dae Soo,Kang, Soon Hyung Elsevier 2018 International journal of hydrogen energy Vol.43 No.34

<P><B>Abstract</B></P> <P>In this work, we developed novel titanium oxynitride (TiO<SUB>x</SUB>N<SUB>y</SUB>) nanoparticles with diameter of 25 ± 2 nm and crystalline size of ∼15 nm on hydrothermally grown one-dimensional (1D) TiO<SUB>2</SUB> nanorod (TNR) arrays. Herein, the TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles were synthesized by facile nitridation using TiO<SUB>2</SUB> powder at 100% NH<SUB>3</SUB> gas atmosphere. Titanium oxynitride composed of potentially energetic metal-nitrogen bonds (TiN), compared to the weaker TiO bond, becomes chemically stable in the alkaline environment, and is considered as a suitable material for photoelectrochemical (PEC) system. The PEC performance of TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR (abbreviated as TiO<SUB>x</SUB>N<SUB>y</SUB> @TNR) films was evaluated in 0.1 M KOH solution under solar illumination condition, and achieved the potentially high photocurrent density (<I>J</I>) of 2.1 mA/cm<SUP>2</SUP> at 1.23 V versus reversible hydrogen electrode (RHE) (abbreviated as V<SUB>RHE</SUB>) in the TiO<SUB>x</SUB>N<SUB>y</SUB>@TNR arrays, in comparison with the poor photoresponse (0.7 mA/cm<SUP>2</SUP> at 1.23 V<SUB>RHE</SUB>) of the pristine TNR arrays. A nearly three-fold enhancement was attained in the TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR arrays, attributed to the high visible light absorption and fast carrier separation, due to the hybridization with the visible active TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles in the cascading band alignment between the TiO<SUB>x</SUB>N<SUB>y</SUB> and TNR materials. Furthermore, the introduction of TiO<SUB>x</SUB>N<SUB>y</SUB> layer on the TNR surface quite reduces the interfacial resistance in the solid-liquid interface region, and further, the TiO<SUB>x</SUB>N<SUB>y</SUB> layer contributes to the passivation of the surface states (<I>e.g.,</I> defect, trap sites etc.) where the charge recombination reaction frequently happens, leading to the improvement of PEC performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Titanium oxynitride (TiO<SUB>x</SUB>N<SUB>y</SUB>) nanoparticles on 1D TiO<SUB>2</SUB> nanorod was well developed. </LI> <LI> TiO<SUB>x</SUB>N<SUB>y</SUB> nanoparticles were synthesized by nitridation using TiO<SUB>2</SUB> powder at 100% NH<SUB>3</SUB> gas. </LI> <LI> Photocurrent density of 2.1 mA/cm<SUP>2</SUP> at 1.23 V<SUB>RHE</SUB> in the TiO<SUB>x</SUB>N<SUB>y</SUB>@TNR arrays was achieved. </LI> <LI> A three-fold enhancement was attained in the TiO<SUB>x</SUB>N<SUB>y</SUB> decorated TNR film versus TNR film. </LI> </UL> </P>