KUMAR C R S, DEEPTHI S, JHA A
047860 KUMAR C R S, DEEPTHI S, JHA A ( Physics Dep, GITAM Univ, Visakhapatnam - 530045, Email: firstname.lastname@example.org) : Charge Transfer Interactions of p - azoxyanisole complexes for electrooptical activity. Asian J. Chem 2020, 32 (7), 1603 - 8.
In particular interactions due to organic - inorganic molecules results self assembled structures organize supramolecular structures for molecular, electronic and electrooptical properties. Supramolecular structures originated are complexes with organic (p - azoxyanisole) molecule, synthesized with metal nanoparticles (iron, copper and aluminium.) Spectroscopic studies interpret infrared spectra with wavenumbers of characteristic bands in assigned regions; wavenumbers with reduced intensity in Raman spectra attribute metal - organic framework with charge transfer. Designed frame work with dense participation of carriers interpret electron correlation and exchange interaction specifying molecular, electronic and electrooptical properties with Gaussian package using electron density method. Deterministic procedure attribute vital role of charge transfer interactions responsible in formation of complex with improvement in properties responsible for electrooptical activity.
8 illus, 3 tables, 19 ref
KAMAKSHI T, SUNDARI G S
047831 KAMAKSHI T, SUNDARI G S ( Physics Dep, Mallareddy Engineering Coll, Dhulapally, Secunderabad - 500014, Email: email@example.com) : Photocatalytic degradation of methylene blue via cobalt doped fe3o4 nanoparticles. Asian J. Chem 2020, 32 (6), 1413 - 20.
Cobalt doped Fe3O4 i.e., CoFe3O4 nanoparticles of different concentrations (0, 0.5, 1.0, 1.5, 2.0, 2.5 mol% were represented as Fe3O4, CF1, CF2, CF3, CF4, CF5, respectively) were synthesized using a chemical co - precipitation technique. The XRD patterns and FTIR spectra of Co doped Fe3O4 revealed the formation of spinel structure indicating the successful incorporation of cobalt ions with the Fe3O4 structure of the iron ions at octahedral sites. Scanning electron micrographs showed a fine uniform spherical particles. UV spectroscopic analysis showed that cobalt doping in CoFe3O4 nanocomposites influenced the band gap values. These band gap values decreased in the range of 2.76 - 1.61 eV (direct), 2.53 - 0.97 eV (indirect) with increase of cobalt content. The activity of CoFe3O4 in photocatalysis was investigated using methylene blue azo dye under visible light. These results depicted that for 1% cobalt doped Fe3O4 novel material photocatalytic activity was enhanced than all other prepared nanomaterials.
9 illus, 7 tables, 77 ref
DEIVAMANI D, PERUMAL P
047815 DEIVAMANI D, PERUMAL P ( Physics Dep, Alagappa Government Arts Coll, Karaikudi - 630003, Email: firstname.lastname@example.org) : Improved Capacity of LiNi0.8Mn0.1Co0.1O2 Cathode upon Sn(IV) doping by facile co - precipitation method. Asian J. Chem 2020, 32 (6), 1303 - 8.
Nickel rich lithium nickel manganese cobalt oxide is one of the prominent cathode materials in the field of lithium ion battery. The cathode was prepared upon doping with Sn4+ by simple co - precipitation method to develop its discharge capacity. The structural and morphological studies on the cathode material were done by X - ray diffraction and scanning electron microscopy to confirm any structural changes upon doping of Sn4+. The higher discharge capacity of 210 mAh g - 1 with 89% capacity retention was achieved even after 100 cycles at C/3 rate for 0.8 mol % Sn4+ doped lithium nickel manganese cobalt oxide. The structural phase change upon cycling for Sn4+ doped and un - doped cathode was illustrated by differential plot. The ionic radius and high bond stability of Sn4+ that compares Ni2+ might be the reason to prevent structural collapse during Li+ intercalation and de - intercalation process.
4 illus, 1 table, 45 ref
NATCHIMUTHU V, RAVI S, RAMALINGAM M, RENUGA V
047763 NATCHIMUTHU V, RAVI S, RAMALINGAM M, RENUGA V (Physics Dep, National Coll, Tiruchirapalli - 620 001, Email: email@example.com) : Design, Synthesis and in vitro Cytotoxicity Evaluation of New Fluorinated Ionic Salt (S) - (+) - 2,3 - Dihydro - 1H - pyrrolo[2,1 - c][1,4]benzodiazepine - 5,11(10H,11aH) - dione as Strategies for Improving Anticonvulsant Activity. Asian J. Chem 2020, 32 (4), 975 - 80.
The reaction of (S) - (+) - 2,3 - dihydro - 1H - pyrrolo[2,1 - c][1,4]benzodiazepine - 5,11(10H,11aH) - dione (1) with 4 - (trifluoromethyl)benzoic acid (2, C8H5F3O2) in dimethylformamide leads to the formation of C8H5F3O2 (1) as a classical ionic salt 3. The structure of new compound has been characterized by FTIR, 1 H NMR, 13C NMR, HRMS spectroscopy. The new compound was tested for in vitro cytotoxicity evaluation by MTT assay against breast adenocarcinoma cell line of MCF - 7 cells. A new compound 3 (IC50:199 ?M) emerged as minimal toxic when compared to clinical drugs carbamazepine, topiramate and benzodiazepine. A preliminary study of structure activity relationship revealed that the incorporation of fluoro or trifluoromethyl moiety into the compound, even through ionic bond formation, had a great effect on the biological activity and with less toxicity or side effects.
4 illus, 2 tables, 33 ref
ALBERT A A, SAMUEL D G H, PARTHASARATHY V
047701 ALBERT A A, SAMUEL D G H, PARTHASARATHY V (Physics Dep, Hindustan Institute of Technology and Science, Padur, Chennai - 603 103, Email: firstname.lastname@example.org) : Wet Chemical Synthesis of CuO - PVA hybrid nanofluid stabilized by steric repulsion. Asian J. Chem 2020, 32 (3), 570 - 4.
CuO - PVA hybrid nanofluid was synthesized within PVA matrix by a simple wet chemical precipitation method. The influence of rate of addition of precursor (NaOH) on the structure, morphology and stability of CuO - PVA hybrid nanofluids were studied. The structure was confirmed by XRD and UV - visible spectroscopy. High resolution transmission microscopy (HRTEM) images revealed the formation of smaller particles for addition of precursor in solid form or rapid addition (RA), whereas slow addition of precursor (SA) resulted in uniform particle size. The selected area electron diffraction (SAED) pattern of sample SA shows rings with small bright spots indicating that the sample is nano crystalline. The SAED pattern of sample RA shows diffuse rings with lesser number of bright spots indicating that it is less crystalline. The stability studies indicate that both the samples were stable for more than one year.
8 illus, 26 ref
TONGBRAM S, SINGH S D, TONGBRAM B, SHARMA B I
047678 TONGBRAM S, SINGH S D, TONGBRAM B, SHARMA B I (Physics Dep, Assam Univ, Silchar - 788 011, Email: email@example.com ) : Synthesis and structural, optical, photoluminescence and electronic structure studies of SrAl2O4 Phosphor. Asian J. Chem 2020, 32 (2), 420 - 6.
In this work, pure SrAl2O4 phosphor is synthesized using precipitation method annealed at 1000 ?C and characterized by XRD, FTIR, UVvisible, Raman, SEM, EDX, TEM, SAED and photoluminescence spectroscopy. The XRD pattern reveals the unit cell structure of SrAl2O4 as monoclinic. The SEM and TEM images show a non - uniform shape with agglomeration, and its size varies from 10 to 80 nm. The SAED pattern confirms polycrystalline and single crystal in the different selected area with different magnification. Photoluminescence emission shows a peak at 467 nm (blue) when excited at 272 nm wavelength. The electronic structure calculation with the density functional theory (DFT) shows a band gap of 4.4 eV, which is nearly equal to 4.46 eV obtained from the experiment optical absorption spectrum. The findings would be beneficial for furthermore investigations on doping in the pure SrAl2O4 phosphor to enhance its high luminescent intensity and long - lasting for a future technological purpose.
11 iilus, 2 tables, 20 ref
ARUL S, SENTHILNATHAN T
047669 ARUL S, SENTHILNATHAN T (Physics Dep, Jai Shriram Engineering Coll, Tirupur - 638 660, Email: firstname.lastname@example.org) : Kinetics and Photodegradation Study of Congo Red using Mg with Ti/Al Co - Doped ZnO Nanocomposite under UV Light. Asian J. Chem 2020, 32 (2), 369 - 73.
ZnO nanocomposites co - doped with dopants like Mg with Ti or Al were prepared and assigned as ZnO - A and ZnO - B. All the nanocomposites were characterized by XRD, SEM and EDX and its utility towards the photodegradation of Congo red is studied. The present study was carried out in 30 W mercury lamp fitted in batch photoreactor and the effect of decomposition was measured in UV - absorption. Nanocomposite with combination of Ti dopant (ZnO - A) exhibited effective degrading ability to aqueous Congo red solution. A solution of 100 ppm of above concentrated ZnO nanocomposite solution was reduced nearly to 5ppm within 5 h. The photodegradation kinetics revealed that the photodegradation of aqueous Congo red follows first order reaction and showed quite comparable degradation effeciency with earlier reports.
5 illus, 2 tables, 29 ref
JENIFER A, SAKTHIVEL P, SENTHILARASAN K, ARUMUGAM S, SIVAPRAKASH P
047667 JENIFER A, SAKTHIVEL P, SENTHILARASAN K, ARUMUGAM S, SIVAPRAKASH P (Physics Dep, Urumu Dhanalakshmi Coll, Tiruchirappalli - 621 819, Email: email@example.com) : Microwave assisted synthesis of titanium(IV) doped hydroxyapatite and its antibacterial activities. Asian J. Chem 2020, 32 (2), 354 - 8.
A rapid, efficient and cost - effective method for the synthesis of titanium(IV) doped hydroxyapatite using microwave assisted wet chemical method is reported. The synthesized hydroxyapatite and titanium(IV) doped hydroxyapatite (THA) samples were characterized by using XRD, FTIR and HR - TEM with EDAX. The antibacterial activity against Staphylococcus aureus and Escherichia coli was investigated by using the disc diffusion method showed good results. The anti - inflammatory activity by using the protein denaturation method proves to be less inflammable for in vivo applications. The hemolytic test showed that the samples are less hemolytic.
4 illus, 2 tables, 29 ref
AMALA S, RAJARAJAN G , KUMAR E D, DOSS M A, THANIKACHALAM V
047634 AMALA S, RAJARAJAN G , KUMAR E D, DOSS M A, THANIKACHALAM V (Chemistry Dep, Annamalai Univ, Annamalainagar - 608 002, Email: firstname.lastname@example.org) : Design, Synthesis, Spectral and theoretical studies of some picrates. Asian J. Chem 2020, 32 (1), 174 - 82.
The structures of newly synthesized compounds (1 - 3) viz. 3 - ethyl - 5 - methyl - 2,6 - bis(4 - chlorophenyl)piperidin - 1 - ium picrate (1), 3 - ethyl5 - methyl - 2,6 - bis(4 - methylphenyl)piperidin - 1 - ium picrate (2) and 3 - ethyl - 5 - methyl - 2,6 - bis(3,4 - dimethoxyphenyl)piperidin - 1 - ium picrate (3) were confirmed by elemental analysis, FT - IR, 1 H and 13C NMR. The UV - visible spectra, fluoresence, emission properties of synthesized 1 - 3 in different solvents were studied. Compounds 1 - 3 solvatochromic displays a slight effect of the emission and absorption spectrum, indicating a small change in the dipole moment upon excitation of compounds 1 - 3. All the compounds were investigated by DFT. The theoretical geometrical parameters are in good agreement with experimental values.
6 illus, 8 tables, 58 ref
MANIMEKALAI R, CHIDAMBARAM S
047617 MANIMEKALAI R, CHIDAMBARAM S ( Physics Dep, A.V.V.M. Sri Pushpam Coll, Poondi - 613 503, Email: email@example.com ) : Growth and characterization of adipic acid doped potassium hydrogen phthalate: a nonlinear optical single crystal. Asian J. Chem 2020, 32 (1), 79 - 83.
Adipic acid doped potassium hydrogen phthalate (AAKHP) and pure potassium hydrogen phthalate single crystals were grown by slow evaporation method. Single crystal X - ray diffraction analysis was carried out to determine the lattice parameters in a = 6.47 ?, b = 9.59 ?, c = 13.25 ? and space group of Pca21. This confirms the grown AAKHP belongs to the orthorhombic system. Various diffracting planes of the grown crystal were indexed using powder X - ray diffraction study. Fourier - transform infrared studies confirm the presence of various functional groups in the grown crystal. The transmittance spectrum shows that the lower cutoff wavelength is around 290 nm. The nonlinear optical property of the grown crystal has been studied by Kurtz powder second harmonic generation (SHG) analysis. EDAX analysis confirms the presence of various elements in the AAKHP crystal. Vickers micro - hardness studies are used for the analysis of mechanical behaviour of the grown crystal. The paramagnetic nature of the grown crystal was confirmed by vibration spectrum magnetometer technique.
7 illus, 3 tables, 25 ref
SHARMA N, SINDERPAL T
047601 SHARMA N, SINDERPAL T (Physical Sciences Dep, Sant Baba Bhag Singh Univ , Jalandhar - 144 030 , Email: firstname.lastname@example.org) : Sterculia gum: Chemical structure, composition and physico - chemical properties. Asian J. Chem 2020, 32 (1), 001 - 8.
Physico - chemical properties are crucial characteristics of hydrocolloids as they decide the applicability of them. Rheology of system, flow behaviour and mechanical properties make hydrocolloids suitable for food industry. Modification of consistency or texture properties of functional polymers also controls their sensory characteristics, thereby they become significant essences such as thickener, gelling agents, foaming agent, texture modifier, viscosifier, emulsifier, stabilizer and binder. Industrial and pharmaceutical applications are also controlled by some suitable physico - chemical properties of hydrocolloids. The polysaccharide gum exudates constitute a architecturally distinct class of complex biomacromolecules having unique physico - chemical properties. Due to their good bio/tissue compatibility, nontoxicity, they are extensively used in the field of tissue engineering, drug delivery and wound healing. Chemical and molecular architecture of hydrocolloids in turn controls their physico - chemical and functional properties. Sterculia gum is a substituted rhamnogalacturonoglycan (pectic) type exudate gum used as suspending agent, gelling agents, emulsifier, bulk laxative, dental adhesive, drug delivery agent and wound healing agent. It exhibits high water retention capacity, high viscosity and least solubility. Solutions of sterculia gum are viscoelastic and thixotropic. Sterculia gum has been recommended as effective wound dressing material as it can form a intensely adhesive gel when dispersed in minimum ammount of water. Owing to wide applications and distinctive properties of sterculia gum, present work is an endeavor to summarize the molecular organization, chemical configuration and physico - chemical properties of sterculia gum and the factors affecting physico - chemical properties of sterculia gum.
KUMAR R, JYOTSNA, KUMAR A
047591 KUMAR R, JYOTSNA, KUMAR A (Physics Dep, Career Point Univ, Hamirpur, (H.P.), Email: email@example.com) : Barrier height calculation of Ag/n - ZnO/p - Si/Al heterojunction diode. Asian J. Adv. Basic Sci 2020, 8 (1), 47 - 52.
The Ag/n - ZnO/p - Si(100)/Al heterojunction diodes are fabricated by pulsed laser deposition of ZnO thin films are on p - Si. High purity vacuum evaporated silver and aluminum metals were used to make contacts to the n - ZnO and p - Si, respectively. The current?voltage characteristics of Ag/n - ZnO/p - Si(100)/Al structure measured over the temperature range 80 - 300K have been studied on the basis of thermionic emission diffusion mechanism. The Schottky barrier height and diodes ideality factor are determined by fitting of measured current?voltage data in to thermionic diffusion equation. It is observed that the barrier height decreases and the ideality factor increases with decrease of temperature and the activation energy plot exhibit non - linear behavior. This decrease in barrier height and increase in ideality factor at low temperature are attributed to the occurrence Gaussian distribution of barrier heights. The capacitance?voltage characteristics of Ag/n - ZnO/p - Si(100)/Al heterojunction diode are also studied over the wide temperature range.
8 illus, 26 ref
SHINDE R V, KUMBHARKHANE A C
047578 SHINDE R V, KUMBHARKHANE A C (Swami Ramanand Teerth Marathwada Univ, Nanded - 431 606) : Temperature dependent dielectric relaxation studies of halopropane from 10 Mhz to 50 Ghz using a time domain reflectometry (TDR). Appl innov res 2020, 2 (2), 001 - 4.
Temperature dependent dielectric relaxation study of halopropane (1 - Chloropropane, 1 - Bromopropane, 1 - Iodopropane) have been carried out in the frequency 10 MHz to 50 GHz using Time domain reflectometry technique. The complex permittivity spectrum has been fitted with single Debye relaxation spectral function. Non - linear square fit method has been used to obtain dielectric parameters such as static dielectric constant (?0), relaxation time (?), Kirkwood Correlation factor (g) and thermodynamic parameters viz. Entropy and enthalpy. The observed properties of Kirkwood correlation and thermodynamic parameters significantly confirm the intermolecular association and hydrogen bonding in halopropanes.
5 illus, 1 table, 17 ref
SINGH B P, TYAGI S, GAUTAM Y K, MALIK A K, OLIVENCIA C A V
047577 SINGH B P, TYAGI S, GAUTAM Y K, MALIK A K, OLIVENCIA C A V (Physics Dep, Chaudhary Charan Singh Univ, Meerut - 250 004) : Electrochemical sensing of hydrogen peroxide based on nano ? - Fe2O3 modified glassy carbon electrode. Appl innov res 2020, 2 (2), 001 - 5.
Maghemite (? - Fe2O3) nanoparticles were prepared using chemical synthesis method and used for sensing the hydrogen peroxide. The morphology of the ? - Fe2O3 nanoparticles was characterized by scanning electron microscopy. The ? - Fe2O3 nanoparticles were used to modify glassy carbon electrode (GCE) to form nano ? - Fe2O3 modified GC electrode for electrochemical sensing of hydrogen peroxide (H2O2). A potential controlled cyclic voltammetric (CV) technique was performed to sense hydrogen peroxide using nano ? - Fe2O3 modified GC electrode. The nano ? - Fe2O3 modified GC electrode showed excellent electrocatalytic ability towards H2O2 in 0.1M KCl supporting electrolyte. A significant enhancement in anodic peak current was observed for the nano ? - Fe2O3 modified GC electrode than those of bare electrode. The electrochemical characteristics of hydrogen peroxide on nano ? - Fe2O modified GC electrode had been explored in this research communication.
6 illus, 32 ref
HARGUNANI S P, PALASPAGAR R S, SONEKAR R P, OMANWAR S K
047575 HARGUNANI S P, PALASPAGAR R S, SONEKAR R P, OMANWAR S K (Physics Dep, G S Coll khamgaon, Buldana - 444 303) : Photoluminescence study of Sr3Y1 - X(BO3)3:xTb3+ green emitting phosphor. Appl innov res 2020, 2 (2), 001 - 4.
Terbium doped strontium yttrium borate phosphor is prepared by solution combustion method. Structural characterization of Sr3Y(BO3)3:Tb3+ (SYB:Tb) has been carried out with X - ray powder diffraction (XRD) analysis. Particle size of 0.5?2 ?m and perfect element composition were seen in SEM - EDS. Using FTIR at room temperature the presence of [BO3] - group; complete combustion of nitrates, organic material, absence of O - H bond were firmed up. Photoluminescence properties of the phosphor have been investigated by measuring the excitation and emission spectra. Several luminescence bands of Tb3+ ions are observed under 233 nm excitation wavelengths in 350?700 nm spectral region. The emission spectra were composed of three bands, in which the dominated emission of green luminescence SYB:Tb attributed to the transition 5D4?7F5 is centered at 543 nm. The dependence of the emission intensity on the Tb3+ concentration for the Sr3Y1 - X(BO3)3:xTb3+ (0.01 ? x ? 0.05) was studied and observed that the optimum concentration of Tb3+ in phosphor was 3 mol% for the highest emission intensity at 543 nm. The CIE coordinates (X=0.251363409, Y=0.736605581) fall at the border of green region in the CIE 1931 chromaticity.
9 illus, 18 ref
GHOSH S, SADHUKHA M, ROUT S, MALLICK B, HASAN M N, MANDAL C
047359 GHOSH S, SADHUKHA M, ROUT S, MALLICK B, HASAN M N, MANDAL C (National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha - 752 050, Email: firstname.lastname@example.org, email@example.com) : Elemental analysis on the new species of earthworm from Orissa. Explor Anim Med Res 2020, 10 (1), 65 - 9.
Earthworms are natural tillers of the soil and are known as the farmer?s friends. The earthworm physiology is capable of combating pollution and pathogens and is therefore worth exploring. Although effect of pollution on earthworm immune system is being studied, elemental analysis of earthworm is not studied, how pollution affects the elements in earthworms, is not known. New species of earthworm was recorded from the state of Orissa, India. In this study we have tried to understand the elemental composition in a new species of earthworm, Perionyx shyamasreetus (P shyamasreetus) isolated and reported earlier, from the soil of Institute of Physics (IOP) campus, Bhubaneswar, Orissa India. We have performed fluorescence spectrophometry, UV - Vis studies, The Fourier - transform infrared (FTIR) and Proton induced Xray Emission (PIXE) studies on earthworm from the wild to understand the elements that exists in it. We observed that the elements including Sulphur (S), Chlorine (Cl),Potassium (K), Calcium (Ca), Titanium (Ti),Vanadium (V),Iron (Fe), Zinc (Zn), Copper (Cu), Chromium (Cr)are present from the PIXE studies on the tissues of earthworm as trace elements and Fe as minor element while Carbon (C), Hydrogen (H), Nitrogen (N) and S as major element. FTIR spectroscopy and UVVis fluorescence studies reveal the presence of amino acids such as tryptophan, tyrosine and cysteine. The future scope of the study lies in understanding the elemental composition of earthworm in environmentally toxic soils including radioactivity prone areas of Orissa.
3 illus, 2 tables, 16 ref
APARAJITA, KUMAR U
001547 APARAJITA, KUMAR U (Physics Dep, Patna Univ, Patna- 800 001, Bihar, Email: firstname.lastname@example.org) : Coupled plasmonic metallic nanowires to induce localization of surface plasmon polaritons. Bull Pure Appl Sci Sec D 2021, 40D (2), 94-7.
We have studied the influence of the structural disorder on the spatial distribution of the plasmonic field and its propagation in one and two dimensional arrays of coupled metallic nanowires. By solving the three dimensional Maxwell equations we have studied the Anderson localization of surface Plasmon polaritions for arrays of metallic nanowires with varying degree of the structural disorder. We have found that a random distribution of radii of the nanowires leaded to transverse spatial localization of collective surface plasmonic polarition excitations. The characteristic spatial confinement of the plasmonic field found smaller than the optical wavelength which demonstrated that plasmonic structures can be employed to implement the subwave length Anderson localization of the electromagnetic field. We have also found that influence of the metallic loss and the gain of the host medium on the plasmonic Anderson localization modes, loss was compensated by the gain whose strength was much smaller than the loss rate of the metallic component of the plasmonic array. The obtained results were found in good agreement with previously obtained results.
KUMAR J S, KUMAR A
001546 KUMAR J S, KUMAR A (Physics Dep, B.N. Mandal Univ, Singheshwar- 852128, Bihar, Email: email@example.com) : Propagation of surface plasmon waves along multi wall carbon nanotube with gold core. Bull Pure Appl Sci Sec D 2021, 40D (2), 88-93.
We have studied the propagation of surface plasmon waves along multiwalled carbon nanotube with gold core. We have modeled the shells of multiwalled carbon nanotube as impedance sheets with axially directed surface conductivity incorporating inter shell coupling in an integral equation approach. We have found that in low frequency regime optical interband transitions did not occur and guided waves propagated with low attenuation in an multiwalled carbon nanotube which has metallic shells. In the same frequency range the axial polarizability of a finite length multiwalled carbon nanotube has a resonant behavior due the antenna length matching effect. The shells with surface conductivity due to interband transitions suppressed guided wave propagation. Surface Plasmon wave propagation in a multiwalled carbon nanotube with gold core showed that in the near infrared and visible regime the shells behaved as lossy dielectric materials and suppressed surface wave propagation along the gold core. The electromagnetic characteristics of carbon nanotube based antennas have been examined in different frequency regime ranging from the microwave to the visible regime. Carbon nanotube has been demonstrated to play a crucial role connected electrically to planner periodic structures of single wall carbon nanotubes, carbon nanotube bundles and carbon nanotube arrays. The inter shells interaction leaded to inter shell electron tunneling or hopping. Fermi momentum of two incommensurable shells do not coincide within the first Brillouin zone and the inter shell tunneling vanished. In the presence of localized defects inter shell conduction increased and defectfree shells were managed by neglecting intershell conduction. We have used microscopic model for multiwalled carbon nanotube and radiation characteristics were determined by its waveguiding properties, the dispersion equation for guided wave propagation on an infinitely long multiwall carbon nanotube. We have found that the guided wave has strong retardation and high attenuation so that the frequency of a geometric resonance is not connected to the free space wave length but to a shorter effective wavelength that depends on the material properties. The obtained results were compared with the previously obtained results and were found in good agreement.
AMAR A, APARAJITA, SINGH B K
001545 AMAR A, APARAJITA, SINGH B K (Physics Dep, Patna Univ, Patna- 800 001, Bihar, Email: firstname.lastname@example.org) : Mechanical resonator linearly coupled to a normal state single electron transistor and electron transport in mescoscopic conductor. Bull Pure Appl Sci Sec D 2021, 40D (2), 83-7.
We have studied the coupling of normal state single electron transistor and electron transport in mesoscopic conductor. For this we have used a simple model system consisting of a mechanical resonator linearly coupled to a normal state single electron transistor to explore the nonlinear dynamics which arised in non electromechanical systems. We have found that very weak linear electromechanical coupling gave rise to a strongly nonlinear response when the resonator was driven close to resonance. In the weak coupling limit and in the absence of driving, the single electron transistor acts on the resonator like a thermal bath with an effective temperature proportional to the bias voltage; it also damps the mechanical motion and renormalized the frequency of the resonator. We have found that for drive a certain threshold, the mechanical response as a function of frequency becomes strongly nonlinear and the mechanical system displayed many of the characteristics of the Duffing oscillator, frequency pulling, a strongly asymmetric line shape, hystresis and bistability. The electromechanical coupling was found weak. We have described the effect of the single electron transistor on the resonator in terms of simple model which included damping and frequency renormalization terms which are both amplitude dependent. We have found that a calculation of the average mechanical response as a function of drive frequency using these two quantities leaded to results which were found in good agreement with a Monte Carlo simulation of the coupled dynamics. At large amplitudes the effect of the resonator on the single electron transistor charge dynamics can no longer be accounted for by a linear correction to the tunnel rates and the charge transport was strongly modified. The modified charge dynamics loaded to changes in the damping and frequency shift induced by the single electron transistor on the resonator leading in general to an amplitude dependence of these quantities. Such amplitude dependence is generic in non linear oscillators and leaded to the familiar phenomena of asymmetric frequency response hystresis and bistability. The obtained results were found in good agreement with previously obtained results.
MISHRA A, KUMAR A
001544 MISHRA A, KUMAR A (Physics Dep, B.N. Mandal Univ, Singheshwar- 852 128, Bihar, Email: email@example.com) : Electronic band structure and magnetic properties of naked zigzag graphene nano ribbons lying symmetrically. Bull Pure Appl Sci Sec D 2021, 40D (2), 79-82.
We have studied the electronic band structures and magnetic properties of the naked zigzag graphene nano ribbons lying symmetrically on the ribbon’s middle under an external tensile strain along the edge direction by using first principle calculations. We have found that the ground state of unstrained line defects zigzag graphene nanoribbon’s was antiferromagnetism in which the magnetic moment localized on the line defect was negligible. When an external tensile strain was applied along the edge direction, the energy band near the Fermi level is spin-split. The band splitting was enhanced with increasing the strain, leading to an increase of the local magnetic moments on the defect. Graphene nanoribbons with zigzag edges are characterized with special localized states, showing a ferromagnetic order in the same edge but antiferromagnetic order between two opposite edges. The ferromagenetic ordering has been found to exist in graphene materials with defect such as vacancies, topological defects, edges and hydrogen chemisorptions. When the defect position changes a transmission from an antiferromagnetism semiconductor to an antiferro magnetism half metal appears. The tensile strain along the zigzag direction of graphene with topological line defects. The antiferromagnetic coupling between the magnetic moments on the edges and the line defects leaded to a turnover of polarization direction on one edge of a critical value of the tensile strain, causing the line defect zigzag graphene nanoribbon to be ferromagnetic. The obtained results were found in good agreement with previous results.
AMAR A, KUMAR N
001543 AMAR A, KUMAR N (Physics Dep, B.N. Mandal Univ, Singheshwar- 852 128, Bihar, Email: firstname.lastname@example.org) : Quantum conductance of interacting quantum wire by current relaxing backscattering and unklapp processes. Bull Pure Appl Sci Sec D 2021, 40D (2), 73-8.
We have studied the quantum conductance of interacting quantum wire by using current relaxing back scattering and Umklap process. We have derived a general formula for the conductance of interacting quantum wire with good contact and current relaxing processes in the wire. We have shown that for an interacting ballistic wire contacted to leads were generalized to an interacting wire with damping. We have calculated the resistance of an interacting quantum wire which has coexisting ballistic and diffusive channels. Such coexistence is expected for integrable modes where part of the current is protected by a local or quasilocal conservation law. We have found that in such a case the ballistic channel is small and completely dominates the transport so that the system shows ideal quantum conductance. Relevant back scattering at the contact were found and were neglected. We have calculated the resistance of single wall carbon nanotubes caused by a coupling to the phononic degrees of freedom of the tube. Three modes have been taken into account. We have found that there is damping of the phonons due to phonon-phonon interactions which modified the phonon propagator. Backscattering is created by impurities which are often relevant perturbations and completely suppress the conductance below a temperature scale. Irrelevant backscattering due to phonons dominated in clean samples. Taking the electrons in the carbon nanotubes as noninteracting it has been shown that acoustic phonon modes gave rise to resistivity that increases linearly with temperature. The conductance showed thermally activated behaviour. At every temperatures Umklapp scattering at half filling leaded to gaps both in the charge and in the spin sector and thus to thermally activated behaviour. In a device configuration the filling in the tube is usually tuned away from half filling so that the Umklapp term oscillates. In the calculation the electrons are treated as noninteracting. Calculation shows that one electron-electron interactions are included the interactions with phonon modes of the tube alone give resistivity of the right magnitude even at room temperature if standard parameters are used. The obtained results were found in good agreement with previously obtained results.
MAHALAKHSMI A, BASKAR G
001490 MAHALAKHSMI A, BASKAR G (Physics Dep, St. Joseph’s Coll of Engineering, Chennai- 600 119, Tamil Nadu) : Greener synthesis and characterization of cadmium-tellurium quantum dots using aqueous extract of waste orange peel. Indian J Biochem Biophys 2021, 58(1), 56-61.
Cadmium-Tellurium quantum dots are inorganic semiconductor material. In the present study, highly stable CadmiumTellurium (CdTe) quantum dots with good optical properties were successfully synthesized by using waste orange peel extract. Fourier-transform infrared spectroscopy (FTIR) identified the presence of hydroxyl, carboxyl and amine groups. Multifunctional X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of cadmium and tellurium. The average size of the quantum dots was found to be 6nm using Transmission Electron Microscopy (TEM). The cubic zinc blende type crystalline structure of quantum dots was confirmed by X-ray powder diffraction (XRD). Thermal stability was studied using thermo-gravimetric analysis (TGA). The influence of temperature with respect to mass change of 8% was observed at 200C. The high luminescence property exhibits at the wavelength of 502 nm were investigated using photoluminescence analysis (PL) and the blue shift is confirmed by UV-Visible spectroscopy.
8 illus, 17 ref
GAYEN S, TEWARI S, CHATTOPADHYAY A
001482 GAYEN S, TEWARI S, CHATTOPADHYAY A (Radio Physics and Electronics Dep, Calcutta Univ, Kolkata- 700 009) : Exploring p-channel TFET for optimum cavity-length window in detecting a wide variety of protein-molecules with the effect of their position dependent variability on sensitivity. IETE Tech Rev 2021, 38(4), 408-17.
The performance of a sub-100-nm gate-length p-channel TFET-based biosensor (pTFET-BS) covering a wide range of protein-molecules is presented, and for the first time the optimized length-range of the nanogap cavity of the biosensor through the modeling of the presence of discrete number of biomolecules, followed by shift-saturation in corresponding transfer characteristics, is reported in this paper. Furthermore, considering a real time process related over-etching effect, a variability study on the random position of the conjugated protein-molecules within the cavity, followed by a corresponding statistical analysis, are carried out. Results show that 85% to 95% (65–85%) of total combinations produce beyond 50% of maximum Vth- (IDS-) sensitivity values, ensuring stability and hence reliability of the proposed sensor device.
5 illus, 3 tables, 23 ref
KUMARI V, SAXENA M, GUPTA M
001475 KUMARI V, SAXENA M, GUPTA M (Electronic Science Dep, Delhi Univ South Campus, New Delhi) : Sensitivity assessment of ringFET architecture for the detection of gas molecules: Numerical investigation. IETE Tech Rev 2021, 38(3), 294-302.
TCAD-based numerical investigation of RingFET has been presented in this paper for the detection of gas molecules. Sensitivity of the device has been assessed by calculating the change in off-state current with the change in gate work-function (which changes due to the presence of gas molecule). The behavior of the device has also been compared with the equivalent bulk MOSFET and it was observed that RingFET architecture shows 23% higher sensitivity against gas molecules than equivalent bulk MOSFET. Also, the degradation in device sensitivity with applied drain bias is higher in bulk MOSFET. Optimization in the sensitivity parameter has been done by using different channel materials like GaN, InGaN, and GaAs. Compared to GaAs and silicon, GaN-based RingFET is more sensitive towards gas molecules in the sub-threshold region (due to the wider band gap) besides having lower drain current than GaAs and silicon-based RingFET.
8 illus, 28 ref
RANI M, DHOK S B, DESHMUKH R B, KUMAR P
001468 RANI M, DHOK S B, DESHMUKH R B, KUMAR P (VNIT, Nagpur, Maharashtra- 440 010) : Compressed signal classification using informed instance selection. IETE Tech Rev 2021, 38(2), 206-20.
Compressive sensing (CS) eases signal acquisition by relaxing the barrier of Nyquist rate. It randomly samples the signal at a rate proportional to the signal sparsity. This compresses the signal at the time of sensing. This superiority of CS is hindered by the complex reconstruction algorithms. The way-out is proposed by an advanced area of CS, in which signal processing is directly done on compressive measurements, avoiding reconstruction. This area is known as compressed signal processing (CSP). It saves power and time and also reduces the computational complexity drastically. CSP is best suited to real-time condition monitoring scenarios where devices are power constrained. These devices generate massive amount of unlabeled data, labeling of which is done manually to train a classifier for condition monitoring. This is quite laborious and time-consuming task. To overcome this burden, use of informed instance selection scheme of active learning (AL) is proposed in this paper. Using this technique, the classifier can be trained even if the data have only few labeled instances. Thus, combining CSP with AL improves the performance of condition monitoring systems to a great extent. The simulation results show that the significant improvement can be obtained using the proposed method.
14 illus, 3 tables, 41 ref
SINGH P, KUMARI V, SAXENA M, GUPTA M
001467 SINGH P, KUMARI V, SAXENA M, GUPTA M (Electronic Science Dep, Delhi South Campus Univ, New Delhi- 110 021) : TCAD-Based assessment of dual-gate MISHEMT with sapphire, SiC, and silicon substrate. IETE Tech Rev 2021, 38(2), 197-205.
This paper examines the DC performance of Dual-Gate MISHEMT with different substrate material such as sapphire, silicon carbide SiC, and silicon. The performance parameters evaluated are threshold voltage, drain current, transconductance, and drain conductance. It is observed that DGMISHEMT with the sapphire substrate and HfO2 gate dielectric results in positive threshold voltage shift from −4.7 to −3.8 V( ∼ 19%) and also degrades the drain current as compared to the device with silicon nitride gate dielectric due to the reduced channel charge concentration. But the device with HfO2/Al2O3 gate stack maintains 182 mA/mm of IDS along with a positive threshold voltage shift of 14.8% as compared to DG-MISHEMT with Si3N4 gate dielectric and sapphire substrate. A similar performance has been observed with Dual-Gate MISHEMT with SiC and silicon substrate. The device, having the silicon substrate and HfO2/Al2O3 gate stack, shows a positive threshold voltage shift of ∼ 53%, but as a trade-off the drain current reduces to 158 mA/mm as compared to 183 mA/mm of the device at low drain bias with the sapphire substrate and Si3N4 gate dielectric.
8 illus, 4 tables, 28 ref
HU Y, WANG Z, ZHANG X
001458 HU Y, WANG Z, ZHANG X (Shanghai Univ, Shanghai, People’s Republic of China) : Steganography in social networks based on behavioral correlation. IETE Tech Rev 2021, 38(1), 93-9.
This paper proposes a secure steganographic method in social networks based on the behavioral correlation between the sender and his friends. A sender transmits secret data to one of his friends in social network by marking “love” on the news published by his friends. To avoid behavioral abnormality, the sender lets the value of “love” marking probability on each news in proportion to the number of “love” marks made by his friends. As a result, the “love” marks carrying secret data are indistinguishable from other normal “love” marks. Although a receiver does not know the “love” marking probabilities, he can still extract the secret data by observing the “love” marks. The security performance of the proposed steganographic method is satisfactory when examined by a proposed behavioral steganalysis method which is able to defeat existing behavioral steganographic methods.
4 illus, 18 ref
YAO Y, ZHANG X, WU H, WANG Z, WANG J
001457 YAO Y, ZHANG X, WU H, WANG Z, WANG J (Shanghai Univ, People’s Republic of China) : A novel location privacy protection algorithm for social discovery application. IETE Tech Rev 2021, 38(1), 82-92.
With the development of smartphones and mobile wireless network, social discovery applications are becoming more and more popular now. These applications help users to chat with nearby people and make friends. However, the location of a user could be exploited by attackers in some situations. This paper concentrates on the protection of location privacy in social discovery application. Firstly, we formalize the location attack problem using probability theory. Then we propose a new distance obfuscation method to defend the location inference attack. Guided by entropy theory, we obfuscate the distance between two users with a specific probability instead of random obfuscation to make the inference attack more difficult. To keep the balance between the privacy level and the service quality, we resolve the optimal mechanism. Experimental results show that the proposed method performs well in protecting the users’ locations without significantly compromising the quality-ofservice of social discovery applications.
7 illus, 24 ref
LI H, JIN S
001456 LI H, JIN S (Shenyang Univ of Technology, Liao Ning- 110 870, People’s Republic of China) : Text steganalysis based on capsule network with dynamic routing. IETE Tech Rev 2021, 38(1), 72-81.
With the growth of natural language processing technology, coverless text steganography has attracted the attention of a large number of researchers. Most existing text steganalysis methods are based on traditional neural network to extract and analyze the semantic features of automatically generated steganographic text. However, due to the limitation of traditional neural networks to preserve subtle features, these methods cannot obtain satisfactory results when detecting the differences between steganographic text with low embedding rate and natural text. This paper demonstrates that using a capsule network to detect whether the natural text contains secret information and gets robust and accurate performance. The capsule network extracts and preserves the sematic features of text, analyzes the subtle differences between steganographic text and natural text. To strengthen the generalization of the method, we choose word2vec to vectorize text and use steganographic text generated based on RNN and variable-length coding as the data set for experiments. Experimental results show that detection accuracy of our method can achieve 92% in steganographic text with the low embedding rate (1–3 bit/word), which is about 7% higher than that based on other neural networks; in high embedding rate (4–5 bit/word), the detection accuracy can reach more than 94%.
5 illus, 3 tables, 39 ref
MA Y, XU J, ZHANG Y, LIU F, LUO X
001455 MA Y, XU J, ZHANG Y, LIU F, LUO X (Henan Normal Univ, Xinxiang- 453 007, People’s Republic of China) : Vector separability measurement based fast feature selection for detecting images information hiding. IETE Tech Rev 2021, 38(1), 56-71.
Images are adopted as information hiding carries in recent years, which has brought challenges to multimedia forensics and security. In order to improve the feature selection speed while maintaining the detection accuracy and reducing the feature dimension, this paper proposes a fast feature selection method for detecting stego image with hiding information. First, a feature component separability criterion is proposed based on the inter-distance and inner-distance difference to measure the separability of steganalysis feature components, providing a basis for constructing candidate feature components. Second, the high-dimensional steganalysis feature is extracted from the training set containing the cover images and corresponding stego images. Then the separability value of each feature component is measured based on the above criterion. And candidate feature vectors are constructed based on the separability values of feature components. Third, a feature vector separability measurement, providing a direct basis for the feature component selection to measure the contribution of the candidate feature vector to the classified image classification. The candidate feature vector with the largest value is chosen as the final selection feature. The dimension of the feature selected by this method is exceedingly smaller than the original feature dimension, so the time cost of the subsequent classification training can be significantly reduced. A series of experiments based on the Bossbase image database have shown that: compared with the recent steganalysis-α method and the FSSG method, the proposed method can significantly improve the feature selection speed while maintaining the detection accuracy and reducing the feature dimension.
6 illus, 4 tables, 18 ref
REN Y, ZHONG S, TU W, YANG H, WANG L
001454 REN Y, ZHONG S, TU W, YANG H, WANG L (Wuhan Univ, Wuhan- 430 072, People’s Republic of China) : A SILK adaptive steganographic scheme based on minimizing distortion in pitch domain. IETE J Res 2021, 38(1), 46-55.
SILK, as an efficient speech codec, has been widely used in real-time interactive communication and can be a good carrier for hiding information. This paper proposes a secure steganographic scheme in SILK pitch domain based on speech signal correlation and statistical distribution of pitch lags. Considering that even minor modification of pitch lags will reduce time correlation of speech signal and the statistical characteristics will be disturbed, this paper elaborately designs a distortion function to measure the loss of signal correlation and statistical features introduced by embedding operation. Using syndrome-trellis codes, this paper realizes a SILK adaptive steganography algorithm based on a minimum distortion framework in pitch domain. Experiments show that the proposed scheme can maintain good voice quality and resist the detection of existing steganalysis schemes.
5 illus, 2 tables, 30 ref
YU Z, LI F
001453 YU Z, LI F (Shanghai Univ of Electric Power, Shanghai, People’s Republic of China) : High-capacity constructive steganography using optimal texture block synthesis. IETE J Res 2021, 38(1), 36-45.
In this paper, we design a new high-capacity constructive steganographic scheme by optimal texture image block synthesis. First, original texture pattern is divided into multiple seed patches, which are hashed into a blank stego pattern by the key. Furthermore, we employ generated seed patches to reconstruct a candidate pattern, which is scanned by sliding window to generate a series of candidate texture blocks. Subsequently, we sort these candidate texture blocks and select the appropriate ones that their serial number equals to the secret messages to achieve information hiding. After theses texture blocks containing secret messages are hashed into the stego pattern by the key, the remaining positions of stego pattern are sequentially filled with the optimal candidate texture patches by calculating the least square error. Finally, the stego pattern is completely synthesized as the constructive stego image. Compared with the existing schemes, our proposed scheme has a significant high embedding capacity, while keeping a higher visual quality of stego images.
6 illus, 5 tables, 20 ref
WU H, ZHANG X
001452 WU H, ZHANG X (Shanghai Univ, Shanghai- 200 444, People’s Republic of China) : Game-theoretic analysis to parameterized reversible watermarking. IETE Tech Rev 2021, 38(1), 26-35.
Separable reversible watermarking enables two encoders to separately embed a payload in a cover, and the original cover can be reconstructed by cooperation. It is required to limit the embedding distortion for the two encoders so that the marked content will not be seriously degraded, whereas both encoders expect to embed a sufficient payload. It motivates us to present a two-encoder game related to rate-distortion optimization of reversible watermarking. We investigate non-cooperative game and cooperative game in a parameterized perspective, which provides good generalization. We find the equilibrium strategies for both encoders under constraints. We extend the game to a multistage win-or-lose case, where both encoders want to win the game. We model the game on a rooted tree with unbounded branching and identify the winner once the initial state is given.
4 illus, 23 ref
ZHANG Z, YAO H, XIANG Z, CAO F
001451 ZHANG Z, YAO H, XIANG Z, CAO F (Shanghai for Science and Technology Univ, Shanghai- 200 093, People’s Republic of China) : Self-embedding watermarking algorithm under high tampering rates. IETE J Res 2021, 38(1), 17-25.
A self-embedding watermarking algorithm based on a reference sharing mechanism that has recovery ability under high tampering rates is proposed in this paper. In existing methods, the image recovery ability is often limited under an increasing tampering rate. The proposed method overcomes this limitation by seeking an approximate solution for each character-bit group tampered with. Moreover, the priority assignment of such groups can enhance the accuracy of tampering recovery. Based on this, by using the method proposed in this paper, recovered images always maintain excellent visual quality even at relatively high tampering rates. The experimental results demonstrate the efficacy of the proposed method.
4 illus, 7 tables, 20 ref
GUPTA N D, JANYANI V
001448 GUPTA N D, JANYANI V (Visvesvaraya National Institute of Technology, Nagpur- 440 010) : Analysis of photonic crystal diffraction grating based light trapping structure for gaas solar cell. IETE J Res 2021, 67(5), 714-25.
The paper presents a design and quantitative analysis for an efficient light-trapping structure (LTS) based on Photonic Crystals (PhC) to enhance the performance of thin-film GaAs solar cells. LTS consists of single planar Anti-Reflection coating (ARC) layer at the top assisted by 2D PhC diffraction grating and Distributed Bragg Reflector (DBR) having alternate dielectric layers at the back of the active layer. The structure has been optically analyzed for various absorption layer thicknesses and compared with Lambertian limits, and it has been shown that with optimization of the design carefully, significant enhancement in the cell efficiency will take place for the presented LTS, especially for the devices with very thin absorption layers (typically less than 1000 nm). Further, it is demonstrated that this efficiency enhancement is attributed to the improvement in photon absorption in the wavelength range for which active layer thickness itself is not sufficient for absorption. According to the simulation analysis, the proposed cell efficiency can be enhanced 3.5 times for a 100 nm cell with LTS, and this enhancement shrinks only to 1.5 times for 1500 nm cell. The analysis has shown that for thin cells, the contribution by the optimized LTS is the main reason behind efficiency enhancement whereas the contribution from ARC remains almost constant. The evaluation of the performance of the proposed structure concerning the angle of incident light and fabrication tolerances has also been done, indicating improved performance. The paper also presents the quantitative and comparative analysis of the proposed design with different compatible designs such as a cell having double layer ARC and a cell having pyramidal ARC with PhC as BR design. Their analysis also predicts that the LTS especially BR are more important for thinner active layer cells and the cell with a pyramidal ARC with PhC outperforms the other designs.
7 illus, 4 tables, 39 ref
RANI K V, JAWHAR S J
001447 RANI K V, JAWHAR S J (Information and Communication Engineering Dep, Anna Univ, Chennai) : Novel technology for lung tumor detection using nanoimage. IETE J Res 2021, 67(5), 699-713.
Nowadays, nanotechnology is gaining more advantages and widely used in many real-life applications including minute tumor detection and effective diagnosis. Nanoscale imaging technique significantly increases the precision, accuracy of tumor detection, and classification of tumor into benign and malignant. Computerized tomography (CT) scan is important for lung cancer diagnosis and research, because it gives accurate segmentation results in lung tumor. In the proposed NBDS method, nanotechnology based detection scheme is used to detect the lung tumors in nanoscale range. Pulmonary nodules are symptoms of lung cancer. The shape and size of these pulmonary nodules are used to diagnose lung cancer in CT images. In the early stages, nodules are very small, and radiologist has to refer to many CT images to diagnose the disease, causing operator mistakes. Image processing algorithms are used as an aid to detect and localize nodules. Here, the input nanoimage is enhanced by using the technique of unsharp masking with the anisotropic filter. By using toboggan algorithm, lung cancer images are segmented. Nano measuring tool for graphical user interface is developed in MATLAB software to detect the lung tumor area or lung lesion in the body (in nanometers). Image classification and feature extraction are done by K-nearest neighbor (KNN) and support vector machine (SVM) with Bag of Visual Words (BoVW) classifiers. The overall accuracy of 97% is obtained using GLCM and FOSfeatures in MATLAB software. The convolutional neural network (CNN) classifier gives the maximum accuracy of 98.19% in MATLAB 2017a software, and hence, this classifier does not need the feature extraction step. Furthermore, the average time consumption for one lesion segmentation was under 4 s using our proposed method. The self-assembled biocompatible nano technique is created to detect the tumor area (in nanometers), and it automatically evaluates the disease. This novel nanotechnology-based tumor area detection schemes achieve robust, efficient, and accurate lung lesion segmentation in nano CT images.
13 illus, 5 tables, 43 ref
SAMSUDIN N A, ISHAK D
001446 SAMSUDIN N A, ISHAK D (Sains Malaysia Univ, Nibong Tebal- 14300, Malaysia) : Full-bridge LLC resonant high-voltage DC–DC converter with hybrid symmetrical voltage multiplier. IETE J Res 2021, 67(5), 687-98.
This article presents an LLC resonant high-voltage DC–DC converter based on the hybrid symmetrical voltage multiplier that consists of the full-bridge inverter circuit, one resonant tank circuit, one power transformer, and the voltage multiplier circuit. The proposed converter operates below resonance on the negative slope region of DC characteristics curve for realization of zero voltage switching (ZVS) operation. Within this operating region, the power switches and output diodes of the converters generally operate under the ZVS and zero current switching (ZCS) conditions, respectively. The detail structure, design procedure, operation, and steady-state analysis of the proposed converter are thus described. Furthermore, an experimental prototype was built and tested with the input voltage of 100VDC. The results show that the proposed converter is capable to operate under soft-switching conditions, resulting in higher efficiency. The maximum efficiency of the proposed converter of about 96% was recorded at the output power of 550 W.
13 illus, 3 tables, 29 ref
SANKARDOSS V, GEETHANJALI P
001444 SANKARDOSS V, GEETHANJALI P (VIT Univ, Tamil Nadu- 632 014) : Design and low-cost implementation of an electric wheelchair control. IETE J Res 2021, 67(5), 657-66.
This paper discusses the design and low-cost implementation of direction and speed controller for an electric wheelchair actuated using a permanent magnet direct current (PMDC) motor. Most of the works are performed either with the simulation of PMDC motor control with various techniques or studied the performance of a single type of controller in real-time with the wheelchair. In this work, the authors simulated the control of PMDC motor with three different controllers and tuned the parameters for real-time implementation of electric wheelchair control using PMDC motor. The authors attempted the simple solution using push button-based interface as well as a graphical user interface for the direction and speed control of electric wheelchair. The signal processing path of the controller, decode the user command input for the direction and desired speed. The controller generates necessary pulse width modulated signals to the H-bridge driver for directions forward, backward, left, and right direction as well as speed control of wheelchair. The user speed control commands low, slightly medium, medium, high, and very high speed are sensed to limit the speed of wheelchair. The performance capability of the intelligent neural network and fuzzy logic controller is studied and compared with proportional-integral-derivative (PID) controller with variations in speed. The PID, neural network and fuzzy logic controller are designed using Matlab-Simulink for PMDC motor and controller parameters are tuned for driving the wheelchair in the real-time implementation using the ATmega 328P microcontroller. The fuzzy logic controller in the electric wheelchair demonstrated the improved performance with less peak overshoot and faster settling with less oscillation compared to PID and neural network controller.
13 illus, 3 tables, 33 ref
KATARIA D, SANCHEZ G, NAIDU J P, SRINIVASAN M A
001443 KATARIA D, SANCHEZ G, NAIDU J P, SRINIVASAN M A (JK Lakshmipat Univ, Jaipur- 302 026) : Design of flexible tactile array sensor. IETE J Res 2021, 67(5), 646-53.
Flexible electronics is an imminent revolution in industry, where devices can be developed using sustainable materials and processes. Some of the criteria for sustainability are low cost, low energy consumption, recyclability, and biodegradability. Besides, this technology is bringing into existence electronic gadgets that are light weight, flexible, and conform to the human body. In this paper, we describe a prototype tactile array sensor (TAS) that can enhance the existing prosthetic gadgets. As an example, the sensor can be used to detect an approaching object or surface for a prosthetic foot. Finite element method simulations have been done to show thefeasibility of the proposed approach. Flexibility is of importance for prosthetics used by children of growing age for better adaptability, reduced frequency of changes, and creativity in product design [Torres-Jara, Dexterous and Compliant Robotic US 8,662,552 B2,2014]. Once developed, this application for sustainable prosthesis is expected to complement the pioneering work done at the MIT Tata Center toward the development of affordable mobile-enabled diabeticfoot analyzer that has enabled regular monitoring of detection of loss of sensation in the feet of diabetic patients avoiding foot ulcers and leg amputation.
10 illus, 2 tables, 13 ref
RADHANAND A, KUMAR K N B, NAMBURU S, REDDY P S
001438 RADHANAND A, KUMAR K N B, NAMBURU S, REDDY P S (ECE Dep, GRIET, Hyderabad- 500 072) : Implementation of a distributed home automation scheme with custom hardware nodes using ZigBee and MQTT Protocols. IETE J Res 2021, 67(5), 596-602.
Providing safety, security, operational convenience and energy savings are some of the vital goals of a home automation system. A single unified point of interaction for the user is also an important consideration. Each feature requires a different sensor, powering scheme and mounting arrangement. To address each requirement, custom node development is to be prepared with all nodes being part of a personal area network for data transfer. A central node with Internet connectivity can push data to the cloud and the user can be provided access to data on a mobile app. This paper presents the practical implementation of such a distributed home automation scheme with custom-designed microcontroller-based ZigBee enabled hardware nodes for liquid petroleum gas leak detection, window open detection, lights switching control based on occupancy and intrusion detection. Messages are triggered by events and are not periodic to avoid traffic congestion. A central node built around a Raspberry Pi with a ZigBee dongle will serve as a data aggregator which sends messages to our own MQTT (Message Queuing Telemetry Transport) broker. An android mobile app will work as an MQTT client, helps the user to connect the MQTT broker, subscribe to the topics published and makes alerts to the user as soon as an event occurs. The mobile app will also enable the user to switch on lights and other appliances through command messages sent to the MQTT broker and subscribed to Raspberry Pi.
8 illus, 2 tables, 16 ref
KALYAN K, PRATHEEK K V D S N K S, RAJU P, VIVEK Y, NAMBURU S
001437 KALYAN K, PRATHEEK K V D S N K S, RAJU P, VIVEK Y, NAMBURU S (ECE Dep, GRIET, Hyderabad- 500 090) : Adaptive compressed spectrum sensing using neural networks in cognitive radio networks. IETE J Res 2021, 67(5), 587-95.
In today’s era of Internet of Things (IoT) applications, Cognitive Radio (CR) is recognized as the most promising technology to access the unused spectrum. Such CR networks can be easily built using Wide-band spectrum sensing. However, the processing of wide-band signals involves a high sampling rate. In such scenario, Compressed Spectrum Sensing (CSS) overcomes the challenges of real-time signal recovery and sampling. CSS uses Sparse signals which are widely used in many applications as they aid in processing large data. Beyond sparsity, all the real-world signals will have special structures (like Restricted Isometric property, Null space property). Moreover, it is very hard to determine the domain in which the signal is sparse. To find this we need a random measurement matrix which plays an important role in extracting the sparse coefficients of the signal. In this paper, a customized neural network is employed to identify the peculiar structures of sparse signals for efficient recovery in real time. The neural network learns and trains an adaptive measurement matrix from the sparse signals to reduce the sensing overhead. The transmitter and receiver systems are configured using Universal Software Radio Peripheral (USRP) boards with LabVIEW® and MATLAB® extensions for peer to peer communications. The implementation results depict the superior performance of neural network based recovery in assimilating the additional structures of real-time signals.
6 illus, 1 table, 14 ref
JAYAKUMAR M, MOHAN N S, VIDYA S B, FINITHA K C, SAMAD A K A, KRISHNA S, SIDHICK A, PRASAD M V N
001436 JAYAKUMAR M, MOHAN N S, VIDYA S B, FINITHA K C, SAMAD A K A, KRISHNA S, SIDHICK A, PRASAD M V N (ISRO, Thiruvananthapuram- 695 022, Kerala) : Vibration testing of absolute pressure sensor for a flush air data system (FADS). IETE J Res 2021, 67(3), 433-9.
Flush Air Data Sensing System (FADS) is an important subsystem required for a winged re-entry vehicle. It essentially makes use of surface pressure measurements located at a suitable position in the vehicle for deriving the air data parameters of the vehicle such as angle of attack, angle of sideslip, Mach number, etc. These air data parameters are used by the control and guidance system for carrying out gain scheduling, trim scheduling of control surfaces and overall flight management. The accuracy of the pressure sensors used in FADS is critical in achieving the targeted accuracy of the air data parameters. In the FADS system considered in this paper, piezoresistive MEMS-based pressure sensors are used. The FADS system is located in the nosecone of the vehicle which is a region prone to vibration during transportation as well as during flight. It is essential that the pressure sensors perform with the desired accuracies in spite of the vibration environment. Sine and random vibration testing are carried out as part of qualification testing of the vibration sensors of FADS. Analysis of the test results shows that the accuracies demanded by the system are provided by the pressure sensors under the vibration environment.
4 illus, 5 tables, 16 ref
PATEL N R, AGRAWAL Y, PAREKH R
001405 PATEL N R, AGRAWAL Y, PAREKH R (Dhirubhai Ambani Institute of Information and Communication Technology, Gandhinagar- 382 007) : Novel subthreshold modelling of advanced on-chip graphene interconnect using numerical method analysis. IETE J Res 2021, 67(1), 98-107.
In VLSI integrated circuits, devices and interconnects are the steady pillars for designing and realization of the entire system. Demand for ultra-low power requirements has become very essential in today’s modern portable and miniaturized electronic gadgets. The subthreshold modelling and its utility for miniaturized gadgets and low power applications have increased tremendously in recent days. Operating devices and interconnects in the subthreshold region profoundly enhance the performance of the system. In this paper, contemporary subthreshold modelling has been energetically taken. The novel modelling of subthreshold for device and on-chip interconnects has been first time presented using the numerical method based finite-difference time-domain (FDTD) technique. The advanced graphene on-chip interconnects have been considered for the performance analysis. The technology node considered is 22 nm. It is analysed that graphene-based MLGNR interconnects possess better performance over copper interconnects. It is also seen that subthreshold region of operation leads to significantly lower power dissipation than in linear region. Power saving with the subthreshold region of operation in case of conventional copper and advanced graphene interconnects is nearly 22% and 26% respectively. The veracious proposed FDTD modelling for the subthreshold region is highly accurate with respect to SPICE simulation results. The average percentage error for transient simulation is less than 2%.
11 illus, 1 table, 28 ref
LIAO C, YANG Y, ZHU Z, HAO M
001394 LIAO C, YANG Y, ZHU Z, HAO M (Xidian Univ, Shaanxi- 710 071, People’s Republic of China) : Total dose radiation response of capacitance characteristic for nano-scale NMOS. IETE J Res 2021, 67(4), 532-7.
The carrier transport in uniaxial strained Si N channel metal oxide semiconductor field effect transistor (NMOSFET) irradiated by gamma rays is analysed. Based on the total dose irradiation effect, an analytical model for differential capacitance of uniaxial strained Si Nano NMOSFET is established. Based on this model, numerical calculation is carried out by MATLAB. The influence of geometric parameters and total dose on differential capacitance is simulated. Meanwhile, the simulation results match the calculation results very well, which validate the accuracy of the model. Therefore, the model provides a good reference for the irradiation reliability of uniaxial strained Si nano NMOSFET and the application of strained integrated circuits.
6 illus, 1 table, 24 ref
ANANTHA B, MERUGU L, SOMASEKHAR RAO P V
001391 ANANTHA B, MERUGU L, SOMASEKHAR RAO P V (Osmania Univ, Telangana State) : Polarization reconfigurable corner truncated square microstrip array antenna. IETE J Res 2021, 67(4), 491-8.
In this paper, a simple 2 × 2 polarization reconfigurable planar microstrip array antenna is presented. It is based on electrical switching technology using PIN diodes. Each element of the array is excited with the aid of the corporate feed technique. Each element of the proposed structure consists of a corner truncated square patch connected to parasitic triangular conductors by means of PIN diodes. The array element is configured to facilitate linear polarization (LP), right-hand circular polarization (RHCP) or left-hand circular polarization (LHCP) by means of 4 independently biased PIN diodes. The proposed antenna is designed and simulated using electromagnetic simulation software CST Microwave Studio. In order to experimentally validate the design, a prototype is fabricated on a 1.6 mm thick RT Duroid substrate of relative permittivity εr = 2.2. The performance of the antenna is validated experimentally using 16 PIN diodes. The simulation and measured results for all the polarization states of the array antenna are found to be in good agreement. The measured results have established the polarization reconfigurable ability of the antenna for 5.7–6.0 GHz operating band. The proposed antenna is suitable for C-band point-to-point communication applications.
13 illus, 2 tables, 18 ref
KHYARI N, KHALFALLAH S, BAROUNI Y, BEN J, SLAMA H
001386 KHYARI N, KHALFALLAH S, BAROUNI Y, BEN J, SLAMA H (Sousse Univ, Sousse, Tunisia) : Capacity improvement in low voltage relay aided plc based on decode and forward protocol over middleton class-A channel. IETE J Res 2021, 67(4), 444-52.
We are adopting, in the present work, a cooperative transmission procedure for an in-home communication system as a solution to meet the contemporary needs of the smart grids and smart home. It is composed of a Low Voltage PL channel assisted by a relay station in the presence of an impulsive noise. Our contribution consists of using the Decode and Forward (DF) relaying protocol while adapting the Joint Modulation (JM) technique to the PLC context. The benefits of this integration are highlighted in a comparative study of the system capacities using the DF-JM and the Amplify and Forward (AF) relaying protocols. The transmission channel is affected by an impulsive noise of type Middleton class-A. The evaluation is based initially on signal attenuation model and eventually on Transmission Line Theory. For the latter, a multi-branched cable with loads at the ends is considered when keeping the relay at the optimal selected position. Simulations and mathematical proofs show that the DF JM relaying technique offers more capacity over the AF independently of cable configuration. Furthermore, in the current study, we analyse the effect of load impedance and branch density on the DF-JM PLC as well as their contribution to the system performance while varying the class-A model parameters.
8 illus, 21 ref
RUDYARDJO D, SISWANTO
001323 RUDYARDJO D, SISWANTO (Physics Dep, Airlangga Univ, Surabaya Indonesia) : Gelatin based on tilapia fish bones. Eco Env Cons 2021, 27(2), 931-6.
A research about gelatin synthesis and characterization from tilapia fish bone as basic material has been done. The aim of this research is to find out the influence of temperature variation on drying process on the gelatin creation process from tilapia fish bone in order to find the best temperature in the gelatin creation process. The process of the creation of the gelatin is started from cleansing the material (tilapia bone) from the dirt and flesh remains on the bone by soaking it in the boiling water for couple of minutes. After cleaning it, the tilapio bone is seeped and dried. After being dried, the fish bone is soaked in HCl 5% for about 48 hours long until ossein is formed. Ossein is cleansed until pH value is neutral and then be extracted using waterbath on 90 ºC temperature for 5 hours. The extracted product is filtered and dried in an oven on temperatures vary from 45 ºC, 50 ºC, 55 ºC, 60 ºC, and 65 ºC. The characteristic of the best gelatin sample and meet the standard criteria for the creation of the gelatin is shown by the sample on 45 ºC drying process where the rendemen value 4.11%, water content 6.31%, ash content 1.59%, melting point 24 ºC, gel point 10 ºC, and mollecular weight 385,336 g/mole. On the other hand, on the FT-IR test result, it has been found that sample shows functional groups of C-H stretching and bending, C=O stretching, O-H bending, O-H bending and N-H stretching as functional groups of gelatin creation.
2 illus, 8 tables, 12 ref
MANOHARA B M, THIRUMALA S, KIRAN B R
001298 MANOHARA B M, THIRUMALA S, KIRAN B R (Physics Dep, Government First Grade Coll, Davangere- 577 004) : Assessment of ground water quality of Jagalur Taluk of Davangere District, Karnataka, India. Eco Env Cons 2021, 27(2), 764-9.
The current study deals with the analysis of ground water quality in Jagalur taluk of Davangere district, Karnataka. Twenty different sampling sites were selected for the analysis and parameters estimated include pH, alkalinity, total hardness, sulphate, chloride, total dissolved solids, carbonates, bicarbonates and electrical conductivity. The variations in the physico-chemical parameters in the water were observed and they were compared with BIS standards. Hence, the ground water samples are moderately polluted and can cause health hazards. In this study, the water samples of all the 20 sites of the studied area were quite good (fair) for irrigation purpose due to high salinity of ground water.
2 illus, 3 tables, 18 ref
Kumar P, Singh D P
000905 Kumar P, Singh D P (Physics Dep, Bhupendra Narayan Mandal Univ, Bihar, Email: email@example.com) : The role of cosmic rays in the modulation of lower atmosphere temperature. Bull Pure Appl Sci-Sect C 2021, 40D(1), 69-72.
Observational evidences suggest that there is an apparent relationship between solar variability and the lower atmosphere. The assumption made in climate models that the variation in solar radiation can explain observed variations in the lower atmosphere is not entirely true. Past studies suggest that cosmic rays of both galactic and solar origin might be responsible for temperature change in the lower atmosphere. It is a fact that solar cycle is strongly correlated with the cosmic ray flux therefore it is desirable to search the physical mechanisms which mediate between solar activity and the global temperature. It is suggested
that the observed variation in cloud cover might provide a possible link between varying solar activity and global temperature. Some other mechanisms might also be playing their roles in modulating the earth’s atmospheric processes. In this research article, we have attempted to explain how cosmic rays could modify the terrestrial temperature.
2 illus, 21 ref
Amar A, Singh B K
000904 Amar A, Singh B K (Physics Dep, Bhupendra Narayan Mandal Univ, Bihar, Email: firstname.lastname@example.org) : Single electron transistors as position detectors for nano- electomechanical systems. Bull Pure Appl Sci-Sect C 2021, 40D(1), 63-8.
We have studied the single electron transistors are extremely sensitive devices as position detectors for nanoelectromechanical systems. Suspended carbon nanotubes have observed a reduction of the mechanical resonance frequency of the fundamental bending at low bias voltages near the degenerate region. This effect is a precursor of the mechanical instability and thus of the current blockade. We have found that the consequence of a capacitive electromechanical coupling in a suspended single electron transistor when the supporting beam is brought close to the Euler buckling instability by a lateral compression force. The result is that the low bias current blockade originating from the coupling between the electronic degrees of freedom and the classical resonator enhanced by several orders of magnitude in the vicinity of the instability. These results are a direct consequence of the continuous nature of the Eular buckling instability and the associated critical slowing down of the fundamental bending mode of the beam at the instability. Our results frequently have close and instructive analogies with mean field theory of second order phase transitions. In order to increase energy, we can increase the electrostating coupling between the oscillator and the single electron transistor, since energy depends quadratically on electrostatic force and a large change in the gate voltage is found when electrons tunnel. In the way of reducing oscillator spring constant in a controlled manner is to operate a doubly clamped beam subject to a lateral compression force. Under the action of the lateral compression force the system exhibited a continuous transition from a flat to a blockade state, while the fundamental bending mode became softer as approached the mechanical instability. We have found that near the buckling instability the current blockade induced by the mechanical resonator is strongly enhanced, rendering this effect. The obtained results were found in good agreement with previously obtained results.
2 illus, 24 ref