Journal Articles
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Item 1 V, 20 nW True RMS to DC Converter based on Third Order Dynamic Translinear Loop(Taylor and Francis Ltd., 2023) Mansoor, C.B.; Patii, A.; Rekha, S.This paper presents a novel current-mode true RMS–DC converter based on the dynamic translinear principle. The converter is designed using a third-order translinear loop, resulting in a very compact and simple circuit. The proposed circuit is designed in 65 nm CMOS technology, operates with 1 V power supply, has only 14 transistors and performs satisfactorily over a wide input current range of 300 nA–950 nA and for a frequency range of 600 Hz–650 kHz for a capacitance value of 10 nF. The frequency range of operation can be tuned by varying the external off chip capacitor and the bias current. The circuit consumes 20 nW static power, 1.6 μW maximum dynamic power and offers the lowest FOM among the other RMS–DC converter circuits presented in the literature. Comprehensive mathematical analysis along with the post layout simulation results confirm the validity of the proposed circuit. To test the use of converter in real world scenarios, the proposed converter is introduced within a typical ECG detection system and the results show that the circuit is an attractive solution for RMS–DC conversion in low-voltage low-power applications. © 2023 IETE.Item 1,3,4-Trisubstituted pyrazole bearing a 4-(chromen-2-one) thiazole: Synthesis, characterization and its biological studies(Royal Society of Chemistry, 2015) Harikrishna, N.; Isloor, A.M.; Kulal, K.; AlObaid, A.; Fun, H.-K.A new series 3-{2-[N?-(1,3-disubstituted-1H-pyrazol-4-yl-methylene)-hydrazino]-thiazol-4-yl}-chromen-2-one (10a-l) was synthesized by a multi-step reaction. All the synthesized compounds were characterized by IR, NMR, and mass spectral studies, followed by elemental analysis. The newly synthesized thiazole compounds were screened for their in vitro antibacterial and antifungal studies against various microorganisms. Antimicrobial studies carried out by the well diffusion method, showed a very good zone of inhibition for both bacteria (at a range of 20-50 mm diameter) and fungi (at a range of 10-30 mm diameter). Minimum Inhibitory Concentration (MIC) required for the 100% inhibition of bacteria and fungi was found to be as low as 15.6 ?g ml-1 for a few of the synthesized compounds. © The Royal Society of Chemistry 2015.Item 1,5-Dibromo-2,4-dimethoxybenzene(2012) Vijesh, A.M.; Isloor, A.M.; Gerber, T.; Brecht, B.V.; Betz, R.In the title compound, C8H8Br2O2, all non-H atoms lie essentially in a common plane (r.m.s deviation of all fitted non-H atoms = 0.0330 Å). In the crystal, weak C-H?O hydrogen bonds connect the molecules, forming chains which extend along the b-axis direction.Item 1-(4-Bromophenyl)-2-(2-chlorophenoxy)ethanone(2012) Shenvi, S.S.; Isloor, A.M.; Gerber, T.; Hosten, E.; Betz, R.In the title compound, C14H10BrClO2, a twofold halogenated derivative of phenylated phenyloxyethanone, the least-squares planes defined by the C atoms of the aromatic rings subtend an angle of 71.31 (17)°. In the crystal, C-H?O contacts connect the molecules into chains along the b-axis direction.Item 1-[(3-Benz-yloxy-2-nitro-phen-oxy)meth-yl]benzene(2012) Fun, H.-K.; Arshad, S.; Ubaradka, S.R.; Shetty, P.; Isloor, A.M.The asymmetric unit of the title compound, C20H17NO4, consists of two crystallographically independent mol-ecules. In one of the mol-ecules, the central benzene ring forms dihedral angles of 2.26 (6) and 58.68 (6)°with the terminal benzene rings and the dihedral angle between the terminal benzene rings is 56.45 (6)°. The corresponding values for the other mol-ecule are 35.17 (6), 70.97 (6) and 69.62 (6)°, respectively. In the crystal, an inversion dimer linked by a pair of C-H?O hydrogen bonds occurs for one of the unique mol-ecules. C-H?? and ?-? [centroid-centroid distances = 3.7113 (8) and 3.7216 (7) Å] inter-actions link the components into a three-dimensional network.Item 1-[5-Acetyl-2,6-dimethyl-4-(5-phenyl-1H-pyrazol-3-yl)-1, 4-dihydropyridin-3-yl]ethanone monohydrate(2012) Islor, A.M.; Malladi, S.; Sundershan, S.; Gerber, T.; Hosten, E.; Betz, R.In the title compound, C20H21N3O 2·H2O, the aza-substitued six-membered ring adopts a L4 B conformation. In the crystal, classical N-H?O, N-H?N and O-H?O hydrogen bonds connect the entities into a three-dimensional network. Intramolecular C-H?O contacts are also observed.Item 1-Cyclohexyl-5-(4-methoxyphenyl)-1H-pyrazole-4-carboxy-lic acid(2011) Fun, H.-K.; Ching Kheng, C.K.; Chandrakantha, B.; Isloor, A.M.; Shetty, P.In the title compound, C17H20N2O 3, the meth-oxy-phenyl unit is disordered over two sets of sites in a 0.715 (4):0.285 (4) ratio. The pyrazole ring forms dihedral angles of 55.88 (16) and 72.6 (4)°with the benzene rings of its major and minor components, respectively. The cyclohexane ring adopts a chair conformation and its C-N bond is in an equatorial orientation. In the crystal, molecules are linked into inversion dimers by pairs of O-H?O hydrogen bonds, generating R 2 2(8) loops..Item 1-Dibromomethyl-4-methoxy-2-nitrobenzene(2009) Fun, H.-K.; Goh, J.H.; Chandrakantha, B.; Isloor, A.M.The asymmetric unit of the title compound, C8H 7Br2NO3, comprises two crystallographically independent molecules (A and B). The nitro groups are twisted from the attached benzene rings, making dihedral angles of 39.26 (9) and 35.90 (9)° in molecules A and B, respectively. In each mol-ecule, the dibromo-methyl group is orientated in such a way that the two Br atoms are tilted away from the benzene ring. An inter-esting features of the crystal structure is the two short Br?Br inter-actions which, together with inter-molecular C - H?O hydrogen bonds, link the molecules into an extended three-dimensional network. The crystal structure is further stabilized by weak C - H?? inter-actions. © Fun et al. 2009.Item 1-Hexyl-3-Methylimidazolium Chloride-Potassium Carbonate Aqueous Two Phase System: Equilibrium Characteristics and BSA Partitioning Behavior(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2014) Iyyaswami, I.; Monteiro, S.L.The partitioning behavior of the model protein (bovine serum albumin) was investigated in ionic liquid (1-hexyl-3-methylimidazolium chloride) -salt (potassium carbonate) based aqueous two phase system (ATPS). The phase diagram with binodal curve and tie lines for the selected ATPS was developed at different temperatures and analyzed through effective excluded volume (EEV) and Othmer-Tobias and Bancroft equations, respectively. The influence of various process parameters like the ionic liquid and salt concentration, system temperature, tie line length, phase volume ratio, and neutral salt addition on partition coefficient/extraction efficiency of BSA protein was evaluated. © 2014 Copyright Taylor & Francis Group, LLC.Item 1.8 V, 25.9 nW, 91.86 dB dynamic range second-order lowpass filter tunable in the range 4-100 Hz(Institution of Engineering and Technology kvukmirovic@theiet.org, 2019) Reddy, J.R.M.K.; Laxminidhi, T.A second-order lowpass Butterworth filter with tunable bandwidth capable of offering a dynamic range of 91.86 dB operating on a supply voltage of 1.8 V is presented. The proposed filter is based on a sub-threshold source follower. The transistor bias currents are switched to enable the bandwidth tuning in the range 4-100 Hz. A proportional to absolute temperature (PTAT) current reference circuit helps to keep the bandwidth intact across process, voltage and temperature variations. The filter, designed in 0.18 ?m standard CMOS process, consumes 25.9 nW making it a potential candidate for portable biomedical applications. © The Institution of Engineering and Technology 2019.Item 11.39 fJ/conversion-step 780 kS/s 8 bit switched capacitor-based area and energyefficient successive approximation register ADC in 90 nm complementary metal-oxide- semiconductor(Institution of Engineering and Technology journals@theiet.org, 2018) Narasimaiah, J.D.; Laxminidhi, T.; Bhat, M.S.In this study, a design technique for low-energy consumption and area-efficient successive approximation register analogue-to-digital converter (ADC) is presented. Digital-to-analogue conversion equivalent voltage is acquired utilising passive sharing of charge between two unit capacitors and integration of the shared charge onto an input sample-and-hold capacitor, via a switched capacitor integrator circuit. The architecture is less parasitic sensitive and low noise, yielding an area and energyefficient ADC. To demonstrate the efficacy of the proposed technique, a ±350 mV 8 bit 0.78 MS/s ADC is designed in a 90 nm complementary metal-oxide-semiconductor process. The ADC core has a small area footprint of 0.00145 mm2 and has a figure-of-merit of 11.39 fJ/conv-step. © 2018, The Institution of Engineering and Technology.Item 14.5 fJ/conversion-step 9-bit 100-kS/s nonbinary weighted dual capacitor array based area and energy efficient SAR ADC in 90 nm CMOS(Institution of Engineering and Technology journals@theiet.org, 2018) Narasimaiah, J.D.; Bhat, M.S.In this work, design technique and analysis of low-energy consumption successive approximation register (SAR) analogue-to-digital converter (ADC) is presented. A dual capacitor array (CA) generates a digital-to-analogue reference voltage with increased accuracy. The CA supports multiple parallel operations to enhance conversion speed. Unit sized capacitors in CAs are few in number and present good capacitance density, thereby providing area efficiency and ease of routeing. A 9-bit SAR ADC using the proposed dual CA, implemented in a 90 nm CMOS process, has a small core area footprint of 0.00371 mm2. At a 1 V supply and 100 kS/s, the ADC achieves a signal-to-noise and distortion ratio of 53.55 dB and consumes 0.47 ?W, resulting in a figure-of-merit of 14.5 fJ/conversion step. © The Institution of Engineering and Technology 2018.Item 1D convolutional neural networks-based soil fertility classification and fertilizer prescription(Elsevier B.V., 2023) Sujatha, M.; Jaidhar, C.D.; Lingappa, M.Sustainable agriculture is essential to meet the demands of the global population. An adequate application of fertilizers is essential for sustainable agricultural productivity. This research aims to determine soil fertility and provide precise fertilizer to improve crop yield. Many researchers have proposed soil fertility classification using deep learning-based approaches, such as extreme learning machines (ELMs) and multilayer perceptrons (MLPs). Although both ELM and MLP have the highest performance, insufficient training data prevent them from being useful. To address this limitation, this research proposes a 1D convolution neural networks (1D-CNN)-based soil fertility classification method that is straightforward, compact, and supports scalar additions and multiplications. To classify soil fertility, the classifier employs laboratory-measured soil data that encompasses electrical conductivity, pH, organic carbon, potassium, phosphorus, sulfur, boron, copper, iron, manganese, and zinc. The proposed approach employs MinMax normalization and the synthetic minority oversampling technique (SMOTE) to improve the classifier performance. The results of soil classification are used to recommend fertilizers. An experimental study using a laboratory-measured soil dataset showed that the proposed technique outperformed ELM and MLP classifiers. The proposed approach outperformed ELM and MLP with a classification accuracy of 97.9%, while ELM and MLP achieved classification accuracies of 69.80% and 87.06%, respectively. The proposed method can help farmers manage soil fertility sustainably to increase crop production. © 2023 Elsevier B.V.Item (1Z)-1-(2,4-Dichloro-phen-yl)ethan-1-one semicarbazone(2009) Fun, H.-K.; Balasubramani, K.; Vijesh, A.M.; Malladii, S.; Isloor, A.M.In the title compound, C9H9Cl2N 3O, the semicarbazone group is approximately planar, with an r.m.s deviation from the mean plane of 0.011 (2) Å. The dihedral angle between the least-squares planes through the semicarbazone group and the benzene ring is 38.76 (9)°. The crystal structure is further stabilized by N - H?O and C - H?O hydrogen bonding. © Fun et al. 2009.Item 2,4-Dichlorobenzyl 2-methoxybenzoate(2013) Isloor, A.M.; Garudachari, B.; Gerber, T.; Hosten, E.; Betz, R.In the title compound, C15H12Cl2O 3, the aromatic rings make a dihedral angle of 10.78 (4)°. In the molecule, there is a short C-H?O contact. In the crystal, C-H?O contacts connect the molecules into C(7)C(8) chains along the b axis. The shortest intercentroid distance between two benzoic acid aromatic systems is 3.7416 (8) Å.Item 2,5-Bis(2,2,2-trifluoroethoxy)phenyl-tethered 1,3,4-Oxadiazoles Derivatives: Synthesis, In Silico Studies, and Biological Assessment as Potential Candidates for Anti-Cancer and Anti-Diabetic Agent(MDPI, 2022) Shankara, S.D.; Isloor, A.M.; Kudva, A.K.; Raghu, S.V.; Jayaswamy, P.K.; Venugopal, P.P.; Shetty, P.; Chakraborty, D.In the present work, a series of new 1-{5-[2,5-bis(2,2,2-trifluoroethoxy)phenyl]-1,3,4-oxadiazol-3-acetyl-2-aryl-2H/methyl derivatives were synthesized through a multistep reaction sequence. The compounds were synthesized by the condensation of various aldehydes and acetophenones with the laboratory-synthesized acid hydrazide, which afforded the Schiff’s bases. Cyclization of the Schiff bases yielded 1,3,4-oxadiazole derivatives. By spectral analysis, the structures of the newly synthesized compounds were elucidated, and further, their anti-cancer and anti-diabetic properties were investigated. To examine the dynamic behavior of the candidates at the binding site of the protein, molecular docking experiments on the synthesized compounds were performed, followed by a molecular dynamic simulation. ADMET (chemical absorption, distribution, metabolism, excretion, and toxicity) prediction revealed that most of the synthesized compounds follow Lipinski’s rule of 5. The results were further correlated with biological studies. Using a cytotoxic assay, the newly synthesized 1,3,4-Oxadiazoles were screened for their in vitro cytotoxic efficacy against the LN229 Glioblastoma cell line. From the cytotoxic assay, the compounds 5b, 5d, and 5m were taken for colony formation assay and tunnel assay have shown significant cell apoptosis by damaging the DNA of cancer cells. The in vivo studies using a genetically modified diabetic model, Drosophila melanogaster, indicated that compounds 5d and 5f have better anti-diabetic activity among the different synthesized compounds. These compounds lowered the glucose levels significantly in the tested model. © 2022 by the authors.Item 2,6-Dichloro-3-nitro-pyridine(2011) Fun, H.-K.; Arshad, S.; Chandrakantha, B.; Isloor, A.M.; Shetty, P.The asymmetric unit of the title compound, C 5H 2C l2N 2O 2, consists of two crystallographically independent mol-ecules. The pyridine ring in each mol-ecule is essentially planar, with maximum deviations of 0.004 (4) and 0.007 (4) Å. Short Cl?O [3.09 (3) and 3.13 (4) Å] and Cl?Cl [3.38 (12) Å] contacts were observed. No significant inter-molecular inter-actions were observed in the crystal packing. © Fun et al. 2011.Item 2-(2,4-Dichlorophenyl)-2-oxoethyl 4-methoxybenzoate(2011) Fun, H.-K.; Chia, T.S.; Shenvi, S.S.; Isloor, A.M.; Garudachari, B.In the title compound, C16H12Cl2O 4, the dihedral angle between the benzene rings is 70.11 (6)°. In the crystal, molecules are linked by C-H?O hydrogen bonds into a three-dimensional network. A C-H?? inter-action is also observed.Item 2-(2-Chloro-phenoxy)acetohydrazide(2010) Fun, H.-K.; Ching Kheng, C.K.; Isloor, A.M.; Dhanya, D.; Shetty, P.In the title compound, C8H9ClN2O 2, the acetohydrazide group is approximately planar, with the maximum deviation of 0.031 (2) Å. In the crystal, the mol-ecules are linked by N-H?N, N-H?O and C-H?O hydrogen bonds, with the acetohydrazide O atom accepting two C-H?O links and one N-H?O link. This results in infinite sheets lying parallel to (100).Item 2-(4-(Diethylamino)-2-hydroxybenzyledene) Hydrazinecarboamide as Corrosion Inhibitor on AA2024-T3 Aluminium Alloy in 0.5 M Hydrochloric Acid Solution(Pleiades Publishing compmg@maik.ru, 2018) Prakashaiah, B.G.; Nityananda Shetty, A.; Amitharani, B.E.A new compound 2-(4-(diethylamino)-2-hydroxybenzyledene) hydrazinecarboamide (DHBHC) was prepared by the condensation of thiosemicarbazide and diethylaminosalicyaldehyde in ethanol–water mixture and its purity was confirmed with IR, H1 and C13 NMR. Anticorrosion properties of this new compound were studied on the aluminium alloy AA2024-T3 in 0.5M HCl solution at 303 K by potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss method. The inhibition efficiency of DHBHC was found to increase with an increase of its concentration. The inhibition efficiency obtained in this study was 96 ± 3% in the presence of 10 × 10?5 M of DHBHC. The surface morphology of the alloy was investigated both in the presence and in the absence of the inhibitor by field emission scanning electron microscopy, 3D profilometry and X-ray photoelectron spectroscopy. © 2018, Allerton Press, Inc.