039099   COLIN M C, HOMS E R, LOPEZ J A (Bruker, Germany, Email: mcdaniel@unt.edu) : A data mining perspective of XRF elemental analysis from Pueblo people's pottery. J Nucl Phys Mat Sci Rad A 2020, 7(2), 129–38.

Hierarchichal clustering was used to identify elemental signatures in artifacts attributed to the Pueblo peoples. The artifacts in this study are pottery samples found at different sites in the state of New Mexico, USA. Three methods were applied: complete, average, and Ward. Their corresponding cophenetic correlation coefficients were used to contrast the three methods. Elemental characterization was only based on X-ray fluorescence excitation from a portable spectrometer with silver anode. The elemental correlations here disclosed by data mining techniques are expected to guide further archaelogical studies and assist experts in the assessment of provenance and historical ethnographic studies.

8 illus, 2 tables, 27 ref

039098   PRIETO E, HALLADO L X, GUERROR A, ALVAREZ I, CISNEROS C (Avenida Univ, Mexico, Email: carmen@fis.unam.mx) : Effect of laser radiation on biomolecules. J Nucl Phys Mat Sci Rad A 2020, 7(2), 123–8.

Time of flight laser photoionization has been used to study the response of some molecules of biological interest under laser radiation. One of the questions of great interest today is the effect of radiation on DNA and RNA molecules. Damage to these molecules can be caused directly by radiation or indirectly by secondary electrons created by radiation. As response of the radiation field fragmentation process can occur producing different ions with kinetic energies of a few electron volts. In this paper wepresent the results of the interaction of 355 nm laser with the nitrogen bases adenine (A) and uracil (U) using time-of-flight spectrometry and the comparison of experimental results on the effects of laser radiation in (A) and (U) belonging to two different ring groups, purines and pyrimidines respectively, which are linked to form the AU pair of the RNA.

4 illus, 2 tables, 16 ref

039096   RIVERA A L, BELTRAN S R, MENDOZA A N (Institute of Nuclear Sciences, Mexico, Email: ana.rivera@nucleares.unam.mx) : Radiation induced reactions of succinic acid in aqueous solution: An agent-based model. J Nucl Phys Mat Sci Rad A 2020, 7(2), 117–21.

An approach to studying the formation of critical bio-organic compounds in the early Earth is tosimulate in the laboratory possible processes that may occur in primitive scenarios. In this context, it can be studied the evolution of succinic acid in an aqueous media exposed to gamma radiation, asstarting material produced more complex prebiotic molecules. To describe the products generated by the interaction of the different elements under radiation, there is a mathematical model that considers chemical reactions as nonlinear ordinary differential equations based on the mass balance of all thespecies, that has been implemented here by an agent-based model. In this simulation, each chemical species involved is considered as an agent that can interact with other species with known reactionrates, and the radiation is taken as a factor that promotes product formation. The results from the agent based model are compared with the molar concentrations of succinic acid, and its products obtained in the lab. Simulation shows the exponential decomposition of succinic acid due to gamma radiation at room temperature in agreement with the laboratory model.

1 illus, 17 ref

039095   RIVERA A L, BELTRAN S R, MENDOZA A N (National Autonomous Univ, Mexico, Email: ana.rivera@nucleares.unam.mx) : Radiation induced reactions of succinic acid in aqueous solution: An agent-based model. J Nucl Phys Mat Sci Rad A 2020, 7(2), 117–21.

An approach to studying the formation of critical bio-organic compounds in the early Earth is to simulate in the laboratory possible processes that may occur in primitive scenarios. In this context, it can be studied the evolution of succinic acid in an aqueous media exposed to gamma radiation, asstarting material produced more complex prebiotic molecules. To describe the products generated by the interaction of the different elements under radiation, there is a mathematical model that considers chemical reactions as nonlinear ordinary differential equations based on the mass balance of all the species, that has been implemented here by an agent-based model. In this simulation, each chemical species involved is considered as an agent that can interact with other species with known reaction rates, and the radiation is taken as a factor that promotes product formation. The results from the agentbased model are compared with the molar concentrations of succinic acid, and its products obtained in the lab. Simulation shows the exponential decomposition of succinic acid due to gamma radiation atroom temperature in agreement with the laboratory model.

1 illus, 17 ref

039094   CINAUSERO M, CASTELLI A M S, BOHUS L S, PALFALVI J, ESPINOSA G (National Autonomous Univ, México, Email: espinosa@fisica.unam.mx) : PADC-NTM applied in ⁷Li+Pb at 31 MeV reaction products study. J Nucl Phys Mat Sci Rad A 2020, 7(2), 109–15.

Passive nuclear track methodology (NTM) is applied to study charged particles products of the reaction ⁷Li+Pb at ~ 31 MeV. It is a contribution to the 8pLP Project (LNL-INFN-Italy) in where we show analternative approach to register charged particle from reaction fragments by PADC detection. The main advantage is that the passive system integrates data over the whole experiment and has its importance for low rate reaction processes. Reaction products as well as scattered beam particles are determined from track shape analysis. Some limitations are inherent to NTM since a priori knowledge is required to correlate track size distribution given by each type of particle emerging from the target. Results show that the passive technique gives useful information when applied in reaction data interpretation for a relatively large range of particle types.

6 illus, 1 tables, 10 ref

039092   CRUZ L P C, MENDOZA A N, BARBERO A H (Radiation Chemistry and Radio chemistry Dep, National Autonomous Univ, Mexico, Email: negron@nucleares.unam.mx) : Stability of glycine in saline solutions exposed to ionizing radiation. J Nucl Phys Mat Sci Rad A 2020, 7(2), 83–7.

The stability of biologically important molecules, such as amino acids, being subjected to high radiation fields is relevant for chemical evolution studies. Bodies of water were very important in the primitive Earth. In these bodies, the presence of dissolved salts, together with organic molecules, could influence the behavior of the systems in prebiotic environments.The objective of this work is to examine the influence of sodium chloride on the stability of the amino acid glycine when subjected to high radiation doses. The analysis of the irradiated samples was followed by HPLC coupled with a UV-VIS detector. The results show that glycine in aqueous solutions (without oxygen) decomposed around 90 % at a dose of 91 kGy. In the presence of salts, up to 80 % ofthe amino acid was recovered at the same dose. Laboratory simulations demonstrate a protective role for sodium chloride (specifically the chloride ion) to glycine against an external source of ionizing radiation.

3 illus, 9 ref

039091   LOPEZ A L M, HURTADO M F G, CASTENEDA J C, MENDOZA A N, BERNAL S R, HEREDIA A (National Autonomous Univ, Mexico, Email: negron@nucleares.unam.mx) : Spectrophotometric study of polymeric dyes gels after a gamma irradiation process for its possible use as a radiation dosimeter. J Nucl Phys Mat Sci Rad A 2020, 7(2), 77–81.

This work aims to evaluate a dosimetric system composed of green malachite supported in agarose. Previous work showed that solutions of green malachite irradiated at 1 to 40 kGy present a linear behavior. This system is a gel composed of green malachite (2.5×10^–3 M), sodium benzoate (1 %), and agarose (1 %) that was exposed tovarious doses of gamma irradiation. The irradiated systems were measured with a UV-V is spectrophotometer at 619 nm. Experimental parameters (such as dose rate,doses, and temperature) were controlled and optimized for reproducible and reliable results. More studies are needed to propose a dosimeter in the system in the range of 1.8 to 4.0 kGy.

3 illus, 1 tables, 7 ref

039090   MIRANDA J (National Autonomous Mexico Univ, Mexico, Email: miranda@fisica.unam.mx) : How do uncertainties in atomic parameters influence theoretical predictions of X-ray production cross sections by proton impact?. J Nucl Phys Mat Sci Rad A 2020, 7(2), 71–6.

The emission of characteristic X-rays induced by proton impact is a phenomenon known since the first half of the 20th century. Its more widely known application is the analytical technique Particle Induced X-ray Emission (PIXE). Several models have been developed to calculate, first, ionizationcross sections and then the subsequent X-ray production cross sections. However, to carry out the comparisons of these predictions with experimental data it is necessary to use atomic parameters databases (fluorescence yields, Coster-Kronig transition probabilities, emission rates) that also have experimental uncertainties. In this work it is demonstrated how these values do not allow to decide which model describes more accurately the cross sections, due to a final “theoretical uncertainty” obtained through the propagation of the original uncertainties.

3 illus, 33 ref

039089   HOLLIDAY R L, YOUNG J M, SINGH S, MCDANIEL F D, ROUT B (Physics Dep, North Texas Univ, USA, Email: mcdaniel@unt.edu) : Feasibility of formation of Ge1-x-ySixSny layers with high Sn concentration via Ion implantation. J Nucl Phys Mat Sci Rad A 2020, 7(2), 65–70.

By increasing the Sn concentration in Ge_1-ySn_y and Ge_1-x-ySi_xSn_y systems, these materials can be tuned from indirect to direct bandgap along with increasing electronic and photonic properties. Efforts have been made to synthesize Sn-Ge and Ge-Si-Sn structures and layers to produce lower energy direct bandgap materials. Due to low solid solubility of Sn in Ge and Si-Ge layers, high concentrations of Sn are not achieved by traditional synthesis processes such as chemical vapor deposition or molecular beam epitaxy. Implantation of Sn into Si-Ge systems, followed by rapid thermal annealing or pulse laser annealing, is shown to be an attractive technique for increasing Sn concentration, which can increase efficiencies in photovoltaic applications. In this paper, dynamic ion-solid simulation results are presented. Simulations were performed to determine optimal beam energy, implantation order, and fluence for a multi-step, ion-implantation based synthesis process.

7 illus, 1 tables, 11 ref

039079   LI G, ZHAO K, YANG H (Xi’an Univ of Posts and Telecommunications, Shaanxi- 710 121, Email: lghcd@163.com) : Feature extraction method for ship-radiated noise based on extreme-point symmetric mode decomposition and dispersion entropy. Indian J Geo-Mar Sci 2020, 49(2), 175-83.

A novel feature extraction method for ship-radiated noise based on extreme-point symmetric mode decomposition (ESMD) and dispersion entropy (DE) is proposed in the present study. Firstly, ship-radiated noise signals were decomposed into a set of band-limited intrinsic mode functions (IMFs) by ESMD. Then, the correlation coefficient (CC) between each IMF and the original signal were calculated. Finally, the IMF with highest CC was selected to calculate DE as the feature vector. Comparing DE of the IMF with highest CC by empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and ESMD, it is revealed that the proposed method can assist the feature extraction and classification recognition for ship-radiated noise.

11 illus, 2 tables, 34 ref

006394   MAGEED H, NADA A S, ABU-ZAID S, ELDEEN R S S (National Institute for Standards, Giza, Egypt) : Effects of waveforms distortion for household appliances on power quality. MAPAN- J Metrol Soc India 2019, 34(4), 559–72.

Harmful effect of harmonics is considered one of the main factors that badly affect the electricity meters’ accuracy and power quality of distribution systems. In this paper, the impact of harmonics generated by various household appliances has been investigated. Household appliances have been divided into four groups according to the similarity of their current and voltage waveforms. The appliances have been collected together according to the reason of the year and time to analyze their waveform. Experimental measurements have been performed using a standard CALMET-TE30 three-phase power quality analyzer. Measurement uncertainty calculations have been taken into consideration to acquire the actual measurement results. The waveforms of these results have been precisely plotted using a specially designed MATLAB program.

22 illus, 27 ref

006374   AHLAWAT A, MISHRA S K, PRASAD M V S N, SHARMA C, GOEL V, RADHAKRISHNAN S R, GUPTA B (CSIR-National Physical Laboratory, New Delhi- 110 012) : Vertical profiling of radio refractivity and associated parameters using tethered balloon over New Delhi. MAPAN- J Metrol Soc India 2019, 34(4), 479–85.

Atmospheric radio refractivity and its vertical gradient affect electromagnetic (EM) wave propagation mostly in the lower troposphere. The vertical profiles of the radio refractivity over New Delhi are very limited that inspired us to study the same using tethered balloon facility. Here, we investigated radio refractivity and its gradient over New Delhi (28°38′10″N, 77°10′17″E) using radiosonde balloon observation for one week (February 21–27, 2014). Vaisala RS 80 radiosonde device used during this experiment comprised of the individually factory-calibrated temperature, pressure and humidity sensors. The resolution of temperature sensor, pressure sensor and humidity sensor is 0.1 °C, 0.1 hpa and 1% RH, respectively. The refractivity measured using radiosonde has been observed to be reduced by 8.6% at 930 masl (mean above sea level) relative to that of ground level (i.e., 230 masl) during up-leg observation (7:00–7:30 PM), while the same has been found to be increased by 10.8% at ground level relative to that of 930 masl during down-leg observation (3:30–4:00 AM). Though it is a small set of information pertaining to refractivity observations using tethered balloon, certainly it can provide micro-insights of the meteorological effects on radio wave propagation better than that of routine experiments. The present study could be crucial for understanding the probable effects on radio wave propagations within atmospheric boundary layer over the study region and would reduce the underlying uncertainties associated with such measurements.

4 illus, 31 ref

006380   CHITTAN M V, CHIMPINENI M K, KUMAR B R, SAILAJA D (Electronics and Physics Dep, GITAM, Andhra Pradesh- 530 045, Email: mani.k.ele@gmail.com) : Design and development of cost-effective system for the measurement of dielectric constant of ceramic materials using PIC microcontroller. MAPAN- J Metrol Soc India 2019, 34(4), 443–50.

In the present work, a simple and low-cost instrument is designed to measure the dielectric constant of ceramic materials using the impedance analyser IC AD5933. The AD5933 is highly accurate impedance converter, which provides the impedance value of the sample with respect to different frequencies. The capacitance and dielectric constant values of the prepared samples are derived from the impedance. A PIC microcontroller is used to interface the circuitry of the impedance analyser and display the measured data on the LCD. In addition, the measured data are exhibited on the serial console of the microcontroller. The measured values were compared with standard impedance analysing device HIOKI-LCR Hitester353250.

6 illus, 1 table, 18 ref

006400   ROHMANN M, CHALLA S, KURRA G, MOGATALA S, SCHRAEDER D (Design and Product Development, Hyderabad, Telangana, Email: mariusz.rohmann@siemens.com) : Switching capability of air insulated high voltage disconnectors. Cent Power Res Inst 2019, 15(2), 153-8.

Need and realization of air insulated high voltage disconnectors switching capabilities (e.g. bus transfer switching), as well as its limits and challenges will be described and discussed.

4 illus, 8 ref

006399   RAJAMANI P, ARAVIND K A, URUKUNDU K, NIRGUDE P, KRISHA B, SHIVAPRASAD P (Central Power Research Institute, Hyderabad– 500 098, Email: rajamani@cpri.in) : Commissioning of UHV indoor double shielded laboratory for radio interference voltage and partial discharge measurement. Cent Power Res Inst 2019, 15(2), 145-52.

In recent years, due to advancement of technology, the transmission voltage levels are goes on increasing. Worldwide 800 kV systems is very common and in India experimental 1200 kV AC is successfully commissioned. Testing of vital equipment of such UHV transmission network is paramount importance to provide uninterrupted, reliable and quality power to the customers. Worldwide few testing laboratories having facility to test upto UHV class equipment, the Ultra High Voltage Research Laboratory (UHVRL) of Central Power Research Institute (CPRI), India is one among them. Recently, 2X600 kV, 2 A, 2400 kVA HVAC test system is commissioned in double shielded indoor laboratory at UHVRL, Hyderabad, India. This manuscript elaborates the experiences of commission of AC test system along with radio interference voltage and Partial Discharge (PD) measurement.

11 illus, 3 tables, 7 ref

006386   GIRAUDET F (High Voltage Products, Siemens AG, Berlin, Email: giraudet@siemens.com) : Various benefits for line surge arrester application and advantages of externally gapped line arresters. Cent Power Res Inst 2019, 15(2), 136-44.

The use of Line Surge Arresters is a well-known application. This cost-effective way has clearly shown the performance improvement for the electricity supply industry. However, there is often resistance to make it a common use. The reduc-tion of outages due to lightning activity and poor grounding makes their application vital. Meanwhile, some users apply this technology also for security of population, switching surge control, line uprating and compaction or live-line working. Even though the use of Externally Gapped Line Arresters can achieve outstanding results by minimizing the investment, this smart protection device shows a mild growth excepting in some specific countries. The EGLA application does not only improve significantly the performance and the operation of the power systems but also improve the design and lower the costs of the construction and the maintenance. The financial benefits are easily demonstrated. Today, proactive main-tenance and trend monitoring is a key point for the transmission lines operators. While existing solutions to assess the conditions of the surge arresters are not suitable and relevant, the new generations of Unmanned Aerial Vehicles (UAVs) are becoming extremely cost-efficient and accurate to inspect transmission line components. This paper intends to present Siemens latest innovations for compact and cost-efficient lightning-proof transmission lines.

1 illus, 1 table, 12 ref

006393   KURUVILLA S P, RENUKAPPA N M, RAJAN J S (Maharaja Institute of Technology, Mandya– 571 438, Email: shantyajish_ece@mitmysore.in) : Development of epoxy with nano and micro fillers for core insulation of composite insulators. Cent Power Res Inst 2019, 15(2), 122-9.

Epoxy composites are extensively used in different applications in high voltage engineering. However, the use of these composites for outdoor insulators has been challenging due to complexities arising out of the conditions of operation of the insulators. Pollution performance of composite insulators is influenced by the nature of the pollution existing, in addi-tion to the combination of stresses acting on the insulators. The use of nano and micro combination of fillers in the epoxy composites is an ideal choice for achieving a proper balance of electrical, thermal and mechanical properties. This paper considers the merits of using combination of micro and nano fillers in an epoxy matrix to demonstrate that such insulation systems would provide better alternatives to the conventional epoxy systems for use as central rod in composite insulation systems for severe contaminated conditions.

1 illus, 13 tables, 17 ref

006373   ADUSUMILLI P, SUNDAR S V N J (R&D BHEL, Hyderabad– 502 032, Email: jithin@bhel.in) : A new criterion for optimal dielectric design of high voltage bushing internal shields in large power transformer. Cent Power Res Inst 2019, 15(2), 116-21.

The High Voltage (HV) bushings are the most sensitive components of power transformers, they provide electrical insula-tion between the HV line and grounded tank, and also provide necessary mechanical support. The majority of transformer breakdowns are attributed to the HV bushings failures which are graded with conductive layers to improve their dielec-tric strength. The design of bushings is quite challenging with tradeoff between the axial and radial electric stresses. The bushing design is also governed by its mounting angle and transformer tank configuration to meet the internal and ex-ternal flashover clearances and creepage requirements. At higher voltage levels, the configuration of HV bushing shield and grounded structural components have significant impact on dielectric withstand strength other than the clearances. Hence, it is very important to study the electrode configuration inside transformer tank for a particular bushing mounting arrangement before finalizing the bushing internal shield design. The 3D electrostatic field analysis of high voltage genera-tor transformer was carried out for different bushing shield configurations to evaluate the electric stress distribution and the dielectric breakdown strength of the equipment was verified experimentally. The authors recommend to study the di-electric design of transformer in tandem with transformer configuration and a new evaluation criterion for optimal design of bushing internal shield is proposed.

8 illus, 2 tables, 5 ref

006398   POTHIYADATH R (Kerala State Electricity Board Ltd, Shoranur- 679 122, Email: rpothiyadath@gmail.com) : Frugal and technological innovations for sustainability in power transmission sector. Cent Power Res Inst 2019, 15(2), 76-83.

This paper attempts to address the various concerns prevailing in Power transmission sector Viz: Right of Way (RoW) is-sues in drawing new power lines, insufficient capacity of existing transmission lines, lack of space for constructing new transmission lines etc., so as to match the Transmission Capacity requirement as per the increase in demand of power. Rightly addressing the above issues, those create effective corridors for transmitting power between power-starving and power-surplus regions at national level would be the need of the hour. Government of India (GOI) is taking various mea-sures to address these issues, which are mostly through innovations that can be applied in up-rating and upgrading of the existing transmission lines and using bipolar DC Transmission links between the regions. Use of DC power transmission, distributed generation, concept of energy producing customer (Prosumer) etc. are few other modern trends in the field of Power. Any innovations that can address the power crisis and that is taking care of the environment will be ensuring the sustainability in power transmission sector, rather than finding out short term solutions. Use of innovations in material science is an emerging technology in High Capacity Conductor (HPC) manufacturing and hence the country is marching towards the sustainable development in power transmission sector also. Government of Kerala (GOK) is also taking several measures to address the various issues as mentioned above, especially it being a state having large population density, thick vegetation and forest coverage. It would be very wise for Kerala to adopt innovative and technological solutions to keep its environmental richness and the sustainability of so called “God’s Own Country”.

5 illus, 1 tables, 10 ref

006402   SANTHAKUMARI S, PADMAVATHY R (Physics Dep, Shrimati Indira Gandhi Coll, Tamil Nadu- 620 002, Email: santhisigc@gmail.com) : Ultrasonic investigation of ion-solvent interactions of drug in non-aqueous medium. J Adv Sci Res 2019, 10(4), 208-11.

The study of molecular interactions in the solutions and liquids are of considerable importance and has been undertaken by  many  researches  now-a-days. Many physical methods are employed  to  study the physical properties of liquids/solutions. They are ultrasonic, thermodynamic, thermochemical and spectroscopic methods. Ultrasonic velocity measurements are highly sensitive to molecular interactions and used to provide qualitative information about the nature and strength of the intermolecular / inter-ionic interactions. Diseases in human beings and animals may be caused by a variety of microorganisms. Antibiotics, antiseptic and disinfectants are prescribed as drugs. The drug-solvent interactions playan  important  role in  the  understanding  of  drug  action.The  term  “Sulfanilamides”  (Sulphanilamide)  is  also  used  to describe  a  family  of  molecules  containing  these  functional  groups.  Sulphanilamide  reduces  vaginal  burning,  itching  and discharge that may occur with this condition. Sulfamerazine is also a sulfonamide antibacterial agent. It is bacteriostatic in nature. Inhibition of dihydrofolic acid synthesis decreases the synthesis of bacterial nucleotides and DNA.  In the present investigation,the  solutions  of  different  molalities  were  prepared  with  the  samples  in  non-aqueous  medium  and  the experiments were carried out from low concentration to higher concentration,at different temperatures.The measured values  of density,  viscosity and  ultrasonic  velocity  were  used  to  compute  adiabatic  compressibility  and  specific  acoustic impedance. An attempt is made to identify the entry solvate into the samples and the entry of biological molecules into the solvate which supports to identify the molecular structure. From the experimental data of ultrasonic velocity, density and viscosity, calculated the acoustical parameters.

4 illus, 4 tables, 27 ref

006405   SUNITHA T, GNANASAMDANDAM C, PRABU K M (Manonmaniam Sundaranar Univ, Tirunelveli, Tamil Nadu, Email: mkprabu1985@gmail.com) : Structural, optical and photocatalytic studies of anatase-rutile mixed-phase undoped and silver-doped titanium dioxide nanoparticles. J Adv Sci Res 2019, 10(4), 144-9.

Undoped and silver-doped titanium dioxide (TiO₂) nanoparticles are prepared by theSol-Gel process using Titanium iso-propoxide (TTIP) as a precursor. The synthesized nanoparticles are characterized by powder X-ray diffraction (PXRD), Fourier  transform  infrared  spectroscopy  (FT-IR),  UV-VIS  spectroscopyandphotocatalytic  studies.  The  powder  X-ray diffraction characterization results showed that the thermal treatment at 500 ºC leads to the formation of anatase-rutile mixed phase TiO₂ nanoparticles. The formation of TiO₂ nanoparticles is also confirmed from the dominant FT-IR peaks observed below 650 cm^-1. The UV-VIS spectroscopy shows that the silver-doping causesnarrowing the optical band gap value  of  ~2.89  eV.  Photocatalytic  investigation  shows  that  the  silver-dopingleads  tohigher  degradation  efficiency  of 86.35%.

10 illus, 34 ref

006376   ANBULAKSHMI C, SELVARAJAN P, SELVARAJ S (Physics and Research Centre Dep, MDT Hindu Coll, Tirunelveli, Tamil Nadu, Email: sharmichandrasekaran@gmail.com) : Crystal growth, XRD, mechanical, FTIR, dielectric and nonlinear optical properties of L-lysine oxalic acid crystals. J Adv Sci Res 2019, 10(4), 117-22.

An organic nonlinear optical (NLO) crystal viz. L-lysine oxalic acid (LLOA) has been synthesized and grown in the form of single crystal by solution method with slow evaporation technique. Single crystal X-ray technique was used to find the crystal lattice parameters and structure. The FT-IR spectrum was recorded to identify the functional groups of the prepared sample. The fluorescence spectrum was recorded for the grown LLOA crystal and colour of emission and region are reported. The micro hardness was measured at different applied loads and work hardening coefficient was evaluated. Dielectric studies were carried out for the grown crystal LLOA and electrical properties were studied. The EDAX spectrum of the sample was recorded to identify the various elements in the crystal. LLOA crystal was powdered and the SHG efficiency was found by Kurtz-Perry technique.

8 illus, 2 tables, 17 ref

006397   PAVAN V D R, ROY S (Physics Dep, National Institute of Technology, Warangal- 506 004, Email: pavan4physics@gmail.com) : Tuning of photonic bandgap in lithium niobate photonic crystal slab structures for wavelength filtering. Indian J Pure Appl Phys 2019, 57(12), 923-7.

In this paper, photonic bandgap of Lithium Niobate (LiNbO₃) based photonic crystal slab with triangular lattice is presented and the tuning of bandgap is discussed as a function of slab’s temperature. A micro-heater with plates parallel to the structure has been assumed for creating localized uniform heating and the corresponding refractive indices and dielectric constants were calculated using thermo-optic effect. MIT photonic bands software is used for the simulations. Tuning of band gap is performed at two wavelengths 632 nm and 1550 nm. It has been observed that the band gap is changing with temperature. The proposed structures can have the applications in wavelength filters, optical interconnectors and optical routers.

5 illus, 31 ref

006385   GALAV K L, PALIWAL S S, MAURYA V, SHARMA G, JOSHI K B (Pure and Applied Physics Dep, Kota Univ, Kota- 324 005, Email: vijaymaurya2414@gmail.com) : Elastic properties and zone centre frequencies of Cu₂O by LCAO method. Indian J Pure Appl Phys 2019, 57(12), 918-22.

The elastic properties and the phonon frequencies at the Brillouin zone centre have been investigated for the cubic cuprous oxide. The calculations under the framework of density functional theory have been carried out by deploying the periodic linear combination of atomic orbitals method. After settling the crystal structure the elastic constants have been determined. The absolute values of elastic constants are well in agreement with the experimental reports. The vibrational frequencies at the centre of the Brillouin zone are classified as the Raman and Infrared active modes and compared with the available experimental data. The contribution of vibrational modes to the Gibbs free energy, entropy and heat capacity has also been found.

3 tables, 46 ref

006395   MISHRA G R, NATH G, PAIKARAY R (Physics Dep, Ravenshaw Univ, Cuttak- 753 003, Email: gnath_phy@vssut.ac.in) : Ultrasonic assisted synthesis of activated carbon for electromagnetic shielding material from rice husk fibre. Indian J Pure Appl Phys 2019, 57(12), 911-7.

Synthesis of any biomaterials/biocomposites for different applications like in electromagnetic wave communication, radar, satellite system needs the processing of its raw material. The suitability of raw material is a challenging task for fabrication technology depending on its type of work performed and efficiency. The surface modification/surface bleaching is performed to facilitate the fillers and matrix for good interlocking between them for improvement in mechanical strength. The material used for microwave absorption or energy storage device in low observable technology (LOT) needs good mechanical strength. The present paper encloses the treatment of raw materials like rice husk with suitable blended chemicals maleic acid with different alcohols. The optimized blended chemicals are determined by computation of different acoustic parameters with the propagation of ultrasonic wave in low frequency range. The rice husk are treated with the optimized blended solution which results in increase of porosity of the material and hence for the fabrication of composites. The element dispersion study images of untreated and treated rice husk signify the suitability of the material for synthesis of microwave absorbing materials.

10 illus, 22 ref

006388   KOLHE S B, UNDRE P B, DESHPANDE V P, KHIRADE P W (Shivaji Arts, Commerce and Science Coll, Aurangabad- 431 103, Email: prabhakarundre@yahoo.co.in) : Dielectric characterization and molecular interaction behaviour in binary mixtures of methyl acetate with 1-butanol and 1-pentanol. Indian J Pure Appl Phys 2019, 57(12), 900-10.

The dielectric constant (ɛ_s) and relaxation time () of binary mixtures of methyl acetate with alcohols (1-butanol and 1-pentanol) have been investigated at fifteen molar concentrations over the entire mixing range at 288 K, 298 K, 308 K and 318 K using time domain reflectometery technique over the frequency range from 10 MHz to 10 GHz. The relaxation in these mixtures can be described by a single relaxation time using the Debye model. The concentration dependent plots of excess dielectric constant (ɛ^E), excess inverse relaxation time (1/)^E, Kirkwood correlation factor (g^eff), thermodynamic parameters such as enthalpy of activation (H) and Gibbs free energy (G) of activation and Bruggman factor (f_B) have been used to explore the complexes formed between unlike molecules, dipolar ordering, hydrogen bond molecular connectivity’s and their strength in the binary mixtures. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of ester-alcohol mixtures.

10 illus, 3 tables, 46 ref

006406   YADAV R K, CHAUHAN P (Physics Dep, Allahabad Univ, Allahabad- 211 002, Email: mangu167@yahoo.co.in) : Estimation of lattice strain in Mn-doped ZnO nanoparticles and its effect on structural and optical properties. Indian J Pure Appl Phys 2019, 57(12), 881-90.

In this study, Mn-doped ZnO nanoparticles with compositional formula Zn_1-x Mn_x O (where, x = 0.00 and 0.10) have been synthesized by simple co-precipitation method. Rietveld refinement of X-ray patterns verifies that the obtained samples have been crystallized in single phase hexagonal wurtzite structure. X-ray peak profile analysis has been used for estimation of crystalline sizes and lattice strain induced by Mn²⁺ doping with the help of Williamson-Hall (W-H) analysis. The morphology of undoped and Mn-doped samples was examined using transmission electron microscopy (TEM) analysis. The mean particle size from TEM results are consistent with results obtained by the Scherrer’s formula and W-H analysis. From the optical studies, the absorbance spectra show the increment in energy band gap by Mn²⁺ doping. Photoluminescence (PL) spectra show different emission peaks due to different defect states. This paper heightens the understanding of structural and optical properties of Mn-doped nanoparticles and paves the path for its potential application in modern optoelectronic devices.

12 illus, 3 tables, 53 ref

006377   ANSARI F K, MAHANUBHAV M D (Physics Dep, Z B Patil Coll, Dhule- 424 002, Email: mahanubhav@rediffmail.com) : Selective and sensitive detection of CO gas by In₂O₃ thick film gas sensors. Indian J Pure Appl Phys 2019, 57(12), 877-80.

This study aims to provide a better fundamental understanding of the gas sensing mechanism of In₂O₃ gas sensors. In the present work In₂O₃ powder has been derived by calcinations of In₂S₃ powder prepared by flux method. Thick film of In₂O₃ has been deposited utilizing a relatively simple and low cost screen printing technique and characterized by scanning electron microscopy and X-ray diffraction. In₂O₃ thick film exhibits much higher sensitivity to CO at 150 ^°C. The corresponding sensitivity is 10.2 with good selectivity, and the response and recovery times are 6 and 14 s, respectively. The results indicate that the In₂O₃ thick film can be used to fabricate high performance CO sensors.

4 illus, 11 ref

006379   CHAUDHARY S, KANIKA K M (Mathematics Dep, Malaviya National Institute of Technology, Jaipur- 302 017, Email: d11.santosh@yahoo.com) : Navier's slip condition and magnetic field effects on unsteady stagnation point flow subject to a stretched plate along to viscous dissipation and joule heating utilizing nanofluids. Indian J Pure Appl Phys 2019, 57(12), 861-76.

This article mainly addresses Navier's slip boundary condition impact on two-dimensional, unsteady magneto hydrodynamic flow of electrically conducting viscous nanofluids adjacent to stagnation region due to a stretchable wall along to viscous dissipation and Joule heating. Nanofluids are taken namely silver-water, copper-water, titanium dioxide-water and alumina-water. Transformation procedure applied reduces the set of nonlinear partial differential equations into a system of nonlinear ordinary differential equations. Resulting governing boundary layer equations are numerically solved by establishing a Keller-box method. Effects of different nanofluids, stretching parameter, slip parameter; solid volume fraction, unsteadiness parameter, magnetic parameter and Eckert number on velocity and temperature distributions are illustrated via graphs and explained in details. Computational values of local skin friction and local Nusselt number for influences of specified parameters are found out and indicated in tabular mode. Moreover, dual solutions exist by cause of negative values of unsteadiness parameter in fluid flow, fluid temperature, wall shear stress and wall heat flux.

17 illus, 4 tables, 46 ref

006396   MISHRA R M, AHAMAD A, PANDEY K N, RAI J S P (Central Institute of Plastics Engineering & Technology, Lucknow- 226 008, Email: rmmcipet@gmail.com) : Effect of nanosilica on the properties of PEI/silicone rubber blend based nanocomposites. Indian J Pure Appl Phys 2019, 57(11), 846-50.

The aim of the present study is to prepare nanocomposites based on binary blends of poly ether imide (PEI)/silicone rubber reinforced with varied loadings of modified nanosilica particles. Nanocomposites have been prepared by melt blending process using twin screw extruder. Thermal behaviour of the developed nanocomposites has been studied with the help of TGA and DMA. Morphological properties have been visualized by SEM. Mechanical properties of the nanocomposites have been determined by universal testing machine. It has been observed that almost all the properties have been found to increase upto 25% with the incorporation of modified nanosilica particles in polymer matrices. Enhancement in various properties may be attributed to better interfacial adhesion and fairly good polymer filler interactions.

3 illus, 4 tables, 20 ref

006389   KUMAR C, KUMAR G, GOYAL R (Electronics & Communication Engineering Dep, Punjab Technical Univ, Kapurthala- 144 601, Email: chakreshk@gmail.com) : Performance evaluation of dynamically flattened gain L-band RAMAN-EDFA-RAMAN hybrid optical amplifier for super dense wavelength division multiplexing system. Indian J Pure Appl Phys 2019, 57(11), 842-5.

In this paper, we have evaluated the performances of super dense Wavelength Division Multiplexing (SD-WDM) system with respect to flat gain. RAMAN-EDFA-RAMAN hybrid optical amplifier (HOA) is the backbone of the system. Further, this model has investigated the effects in terms of L-band flattened gain, output power, crosstalk, and bit error rate with 50 GHz channel spacing. Flat gain greater than 14 dB has obtained at 5 mW and reported the poor performances by 7 mW and 17 mW with the range of 188-192 THz. Gain variation < 2.1 dB has obtained. Highest output power has also obtained at 5 mW, 7Mw and 17 mW accordingly. Final conclusion has recommended that better gain flatness has attained without using any costly components such as gain equalizer and multi-pumping for SD-WDM system.

6 illus, 2 tables, 20 ref

006383   ESME A (Elementary Science Education Dep, Kocaeli Univ, Kocaeli- 41380, Email: asliesme@gmail.com) : Experimental (FT‒IR, FT‒Raman, and UV‒Vis) and quantum chemical calculations on monomer and dimer structures of l-hydroxy-2-naphthoic acid using the DFT and TD‒DFT methods. Indian J Pure Appl Phys 2019, 53(11), 822-35.

The fourier transform infrared (FT‒IR) and fourier transform Raman (FT‒Raman) spectra of l-hydroxy-2-naphthoic acid (1H2NA) in solid phase have been experimentally recorded and analyzed in the region 4000‒400 cm⁻¹. DFT/B3LYP/6‒31G (d,p) calculations were used to determine the optimized molecular structure, conformational, non-linear optical (NLO), natural bond orbital (NBO) analysis, molecular surfaces, Mulliken, NBO charges and vibrational studies of 1H2NA. Obtained results on the geometric structure, vibrational frequencies and UV‒Vis spectral analysis are compared with the observed data. The dimeric structure of 1H2NA with the DFT/B3LYP/6‒31G (d,p) level caused by the shifts of O–H and C=O bands in the vibrational spectra were also studied. Moreover, the spectroscopic and theoretical results were compared with the corresponding properties for monomeric and dimeric structures of 1H2NA. The detailed vibrational assignments were performed with the DFT calculation, and the potential energy distribution (PED) was obtained by the vibrational energy distribution analysis (VEDA4) program. TD‒DFT/B3LYP/6‒31G (d,p) calculations with the SCF (self‒consistent field) in gas phase and ethanol solvent in the excited state were employed to investigated UV‒Vis absorption spectra and the major contributions to the electronic transitions were obtained. The NLO properties such as mean polarizability (<α>), the anisotropy of the polarizability (<Δα>) and the mean first‒order hyperpolarizability (<β>) were computed by using finite field method. The computed values of μ, α and β of the title molecule are 2.2744 D, 17.3225 × 10⁻²⁴ esu and 4.222 × 10 ⁻³⁰ esu, respectively. The high β values and non-zero values of μ indicate that the title compound might be a good candidate for NLO material.

8 illus, 6 tables, 47 ref

006404   SRIVASTAVA R, PANDEY V K, AWASTHI A, AWASTHI A (Physics Dep, Lucknow Univ, Lucknow- 226 007, Email: asheesawasthi@rediffmail.com) : Internal pressure and optical properties of binary mixture of formamide with dimethylaminoethanol and diethylaminoethanol at different temperatures. Indian J Pure Appl Phys 2019, 57(11), 812-21.

The density (ρ) and refractive indices (n) of binary mixtures of formamide (FA) with dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) have been recorded at different temperatures for the whole composition ranges. The experimental values of density data and refractive index are used to estimate the molar refraction (R_m), reduced molar free volume (V_m/R_m), molecular radii (r) and internal pressure (P_int). The deviations of refractive index (Δn_D), molar refractions (ΔR_m), reduced molar free volumes Δ (V_m/R_m) and internal pressures (ΔP_int) have been also calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. The applicability of different refractive index mixing rules is tested against the experimentally measured values and good agreement has been obtained.

4 illus, 4 tables, 42 ref

006381   DAS A S, ROY M, ROY D, BHATTACHARYA S (Electronics and Communication Engineering Dep, Swami Vivekanand Institute of Science and Technology, Kolkata- 700 145, Email: anindyasundardas03@gmail.com) : DC electrical properties and non–adiabatic small polaron hopping in V₂O₅–CdO–ZnO glass nanocomposites. Indian J Pure Appl Phys 2019, 57(11), 803-11.

Semiconducting transition metal oxide (TMO) doped glass nanocomposites xV₂O₅–(1–x) (0.05CdO–0.95ZnO), x=0.3, 0.5, 0.7 and 0.9 have been prepared by melt quenching method. DC electrical conductivity of as prepared glass nanocomposites is are investigated over a wide temperature range. Formation of small polarons has been confirmed from dc electrical conductivity experimental data, whereas conductivity is due to mainly polaron hopping from V⁺⁴ to V⁺⁵ valence state in these glassy systems. Temperature dependent conductivity data have been analyzed using the small polaron hopping (SPH) model. Low, high temperature activation energy, optical phonon frequency and Debye’s temperature have been determined. Conductivity data have been analyzed in view of Mott’s variable range hopping (VRH) models and Greaves VRH models; the density of states at the Fermi level has been evaluated. Various polaron hopping parameters such as polaron radius, polaron binding energy, polaron band width and polaron coupling constant (γ_P) have been estimated. It has been ascertained by these estimated quantities and different approaches that the nature of hopping conduction is non–adiabatic variable range hopping of small polarons. The evaluated values of hopping carrier mobility (μ) and hopping carrier concentration (N_C) are found to depend on composition and temperature.

6 illus, 4 tables, 43 ref

006401   SAINI P K, AHLAWAT D S, DAOUD S, SINGH D (Physics Dep, Govt Coll, Hansi- 125 033, Email: pawansaini2005@gmail.com) : Electronic, mechanical, thermodynamic and optical properties of CdS under pressure. Indian J Pure Appl Phys 2019, 57(11), 793-802.

We report high pressure study of CdS using the full-potential linear augmented plane wave (FP-LAPW) method based on density functional theory approach. In this approach, generalized gradient approximation (GGA) and Engel- Vosko generalized gradient approximation (EV-GGA) have been used for the exchange correlation potential in the calculations. The equilibrium lattice constant, electronic band structure, elastic constants, Debye temperature and melting temperature of binary solid CdS have been calculated under ambient and high pressure. Furthermore, the linear optical properties such as dielectric function, absorption, optical conductivity reflectivity, refractive index and energy loss are computed and analyzed in detail within the energy range up to 14 eV. The obtained results are in good agreement with earlier reported experimental and other theoretical results.

10 illus, 3 tables, 43 ref

006392   KUMARI S, KUMAR S (Mirjanhat +2 High School, Bihar- 812 005, Email: saurabhkumar3988@gmail.com) : The comparative study of one and two phonon relaxation rate with mixed spin relaxation rate. Bull Pure Appl Sci-Sect D 2019, 38D(2), 91-3.

The present research work discusses the different types of the relaxation process and calculates the relaxation time due to mixed spin relaxation rate, one phonon relaxation rate, Indirect two phonon relaxation rate and direct two phonon relaxation rate and their comparative study.

6 ref

006403   SHARMA A (Physics Dep, R. D. S. Coll, Muzaffarpur- 842 001, Email: dramitasharma63@gmail.com) : Electronic band structure of aluminium nitride and gallium nitride crystallizing in the wurtzite and zinc blende structures. Bull Pure Appl Sci-Sect D 2019, 38D(2), 81-5.

We have studied the electronic band structure of aluminium nitride and gallium nitride crystallizing in the wurtzite and zinc blende structures. We have presented theoretical study of atom and orbital projected partial density of state for the group third nitrides. We have compared the energy distribution of electronic states in valence and conduction bands as calculated by means of linear muffintin orbital method. The direct comparison with the appropriate density of state was presented to indicate the extent to which we got direct information about allowed electron states by considering the positions of the maxima and minima of the intensity in spectra. The influence of the core level width and spectrometer broadening was also considered. The good agreement between structures observed in spectra and structures in the calculated density of state allowed for consistent analysis of results. We have compared the amounts of bonding and antibonding states near the band edges for different choices of cations and crystal structures. Since the device applications are based mainly on wurtizite type nitride, particular attention was given to this phase. We examined for wultzite structure the level of anisotropy in the formed chemical bonds. Two kinds of bonds $\mathrm{\pi }$ and $\mathrm{\delta }$ are connected directly with bond lengths. We examined the amount of electronic states available for optical transition as a function of crystal structure, crystallographic direction and presence of cation semicore states. The hydridization between d and p states for different cations and nitrogen were studied. We found that d-p interaction affected the valence band edge and influenced magnitude of the fundamental gap. The obtained results were compared with previously obtained results of theoretical and experimental work and were found in good agreement.

15 ref

006390   KUMAR U, RANJAN R (Physics Dep, G.D. Coll, Begusarai- 851 101, Email: upendra.physics@yahoo.in) : Transmission through surface disordered waveguides and nanowire as drastic influence on coherent scattering. Bull Pure Appl Sci-Sect D 2019, 38D(2), 60-4.

We have studied transmission through surface disordered waveguides in general and a solid basis. Our results showed that desired transmission properties on a waveguide through the roughness of its boundaries can be obtained. This surface scattering approach predicted that how mode specific scattering lengths in waveguides depend on the details of system’s surface roughness. It was shown that previously neglected square-gradient scattering mechanism and predicted that this new scattering mechanism has to be considered together with the conventional amplitude scattering mechanism. Square gradient scattering is related to higher order terms in the disorder strength it can be the major scattering mechanism in system with modest disorder. Surface scattering theory is for long range correlations, which seems to restrict its applicability to very long waveguides. We have extended this surface scattering theory to short, individual waveguides. We found that an observed shift of the amplitude scattering gap could be attributed to the nonvanishing disorder strength. We also found that short wave lengths can exhibit effects predicted for systems with long range correlations leading to drastic changes in their transmission properties. The obtained results were compared with previously obtained results of theoretical and experimental works and were found in good agreement.

12 ref

006391   KUMARI R, KUMAR A (Physics Dep, K.B. Women’s Coll, Madhepura- 852 113, Email: rambha64kumari@gmail.com) : Kondo box effects by varying coupling between dots and chain. Bull Pure Appl Sci-Sect D 2019, 38D(2), 55-9.

We have studied the Kondo box effect by varying the coupling between the dots and the chain. The physics of a Kondo box can be realized in systems of two impurities coupled between them by a finite number of non-interacting sites. Finite size effects can take place together with a magnetic interaction between the impurities of the Ruderman-Kittel-Kasuya-Yosida type. We have found that when Kondo effect is present, the fourth order Ruderman-Kittel-Kasuya-Yosida interaction between the impurities is mediated by the electrons of the non-interacting sites, which are participating simultaneously in the Kondo screening of each impurity. It was also found that other types of magnetic interactions arised such as the Kondo correlated or super exchange interactions. Using vibrational wave functions it was predicted that the interaction between the impurities was mainly due to an interference-enhanced hybridization that generated Kondo doublet states. We analysed a double quantum dot system simultaneously connected to metallic leads and between themselves through a finite number of non-interacting sites. The impurities in such as system are coupled to and interact through a non-interacting linear chain that consisted a quantum box, whose electrons participated in the Kondo’s screening. Thus there is interplay between a bulk continuous Konodo regime and a two impurity Kondo box. We also analysed the transport properties for different values of number of sites of the non-interacting linear chain and for different couplings of the quantum dots with it. The results were valid for temperatures below the characteristic single impurity Kondo temperature. The obtained results were in good agreement with previously obtained results.

14 ref

006375   ALAM M N, APARAJITA (Physics Dep, G.D. Coll, Begusarai– 851 101, Email: nalam884@gmail.com) : Pressure induced pseudomelting implied by negative clapeyron slope for silicon. Bull Pure Appl Sci-Sect D 2019, 38D(2), 51-4.

We have studied pressure induced pseudomelting implied by the negative clapeyron slope for Silicon. Pressure induced amorphization was based primarily on Raman measurements. This does not rule out the possibility of a transformation to a phase which may not have a Raman-active mode such as the primitive hexagonal. Energy dispersive x-ray diffraction measurements on the sample had shown pressure induced annealing of nanocrystalline regions. Since this would have resulted in an increase of the particle size and reduced surface effects, the high pressure behavior should have been similar to that of surface terminated nanoparticles. We have observed that the cubic nano p-silicon undergoes a crystalline-crystalline phase transition to the primitive hexagonal phase under high pressure at ~20Gpa and the amorphous phase arised only on release of pressure. This observation is consistent with the transformation seen earlier in the case of surface terminated nanocrystalline silicon. Nanoamorphous phase thus obtained transforms reversibly to the Ph phase under further pressure cycles. The role of particle size in this reversible behavior. Our results showed that the reversible inter conversion also takes place in bulk amorphous Silicon, provided the pressure release is fast, unlike in the case of nanoamorphous Silicon. Our studies showed that irrespective of the method of preparation or size of the amorphous Silicon particles, it always transforms to primitive hexagonal phase under compression. The obtained results were found in good agreement with previously obtained results.

10 ref

006384   FATTAH A O, RAUF A M, MARDAN B M (Sulaimani Univ, Sulaimaniyah, Iraq) : Efficiency of the diode laser in preventing orthodontic induced pain in Sulaimani City: In vivo, comparative study. Biomed Res 2019, 30(6), 875-9.

This clinical study was conducted to assess the efficiency of diode lasers (940 nm) in preventing orthodontic induced pain. Orthodontic induced pain acts as a barrier for orthodontic therapy, Painless procedures ensure patient satisfaction toward orthodontics which subsequently, improves the quality of oral health.  One hundred twenty orthodontic patients were included and randomly allocated into 4 equal groups (Study, Laser-Placebo, Analgesic, and control groups). A laser beam was applied in contact mode for 1 min duration on the study group. Pain experience was evaluated using a standardized self-administered questionnaire following the Universal Pain Assessment Tool guidelines. Data were analyzed using the statistical package for the social sciences (V. 22). The highest level of pain was experienced at the second day after arch-wire insertion. At the third day a radical decline in pain sensation was observed in the study group, with maximum pain relief at the fourth day, the difference being considered statistically significant at P value ≤ 0.05. The application of Laser therapy was found to be more effective in subsiding orthodontic induced pain than analgesics, taking into consideration the pharmaceutical side effects of analgesics.

3 tables, 40 ref

006382   DHANALAKSHMI G, SARAVANAN V, MOHANAKRISHNAN A K, ARAVINDHAN S (Physics Dep, Madras Univ, Chennai- 600 005, Email: aravindhanpresidency@gmail.com) : Synthesis, crystal structure, Hirshfeld surface, energy framework and molecular docking analysis of two novel carbazole derivatives. Asian J Chem 2019, 31(12), 3017-28.

Carbazole derivatives are important compounds from medicinal point of view because of their widespread biological significance. In the present work two compounds 7-(4-chlorophenyl)-5-methyl-12-(phenylsulfonyl)-12H-naphtho[1,2-b]carbazole (I) and 7-ethyl-5-methyl12-(phenylsulfonyl)-12H-naphtho[1,2-b]carbazole (II) have been synthesized and characterized by XRD, Hirshfeld surface, energy framework and docking analysis. Single crystal X-ray diffraction analysis shows that the compound I crystallizes in monoclinic system with space group P21/n whereas compound II crystallizes in triclinic with space group P-1. In both compounds there are two intramolecular C-H···O hydrogen bonds, which generates two S (6) ring motifs. The crystal packing is stabilized through weak C-H···O and C-H···Cl interactions. The molecules also features C-H···π interactions. The intermolecular interactions of both compounds were analyzed using Hirshfeld surface analysis and two dimensional fingerprint plots, which was confirmed by the XRD data. Energy frameworks were used to calculate the intermolecular interaction energies and their distribution over the crystal structure. Molecular docking studies show that the compounds exhibits antitumor activity.

12 illus, 6 tables, 65 ref

006378   BADKUL A, SAXENA S (CSIR- Advanced Materials and Processes Research Institute (AMPRI), Bhopal- 462 026, Email: san_bpl@yahoo.com) : Assessing factors affecting the flexural behavior of metallic foam in-filled sandwich panel. Appl Innov Res 2019, 1(3&4), 194-9.

The performances of metallic foam are required to improve under flexural loading condition to fulfill the industrial need. In the present work existing literature has been evaluated to understand the factors (foam density, span length, aspect ratio of test specimen, foam core and face sheet thickness) affecting flexural property of foam in-filled sandwich panel. Delamination of foam in-filled sandwich panel has been reported as the major failure mode during the flexural test. It has also been reported that the metallic bonding between metallic foam and face sheet avoid the chance of delamination under flexural loading conditions. There is also a need to have standard test procedure and standard test geometry to evaluate flexural property of metallic foam in-filled sandwich panel. Its evaluation using FEM based techniques are also reported in brief.

1 illus, 1 table, 35 ref

006387   GUPTA P, RATHORE V (Jagran Lakecity Univ, Bhopal- 462 044, Email: priyanka.gupta@jlu.edu.in) : A comprehensive review: SnO₂ for photovoltaic and gas sensor applications. Appl Innov Res 2019, 1(3&4), 184-93.

Tin oxide is remarkable material in today’s research era due to its unique properties in electrical and optical fields. Due to its wide band gap (3.6 eV), it has been used as a core material in many important applications in the field of optoelectronics, spintronics, photovoltaic, thin-film transistors, photocatalysis, dielectrics, sensors and transparent electronic devices. Thin film technology provides many advantages towards photovoltaic area which includes low cost, less material and energy consumption and easy to access. Fabrication of photovoltaic cells by SnO₂ thin films can open the different technological routes for future generation with excellent conversion efficiencies which may range 15 % to 20 %. It is one of the best candidates for gas sensor applications too with highest sensitivity and selectivity behavior, good oxidizing power, strong chemical bonding, non toxicity and unique transport properties. Tin oxide thin films with various combinations of materials can be synthesized by chemical and physical routes. The detailed advancement in various preparation methods and characterization techniques including X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy have been presented and discussed by authors. Characteristics measurement by Valence Band Structure, Photoluminence Intensity and Scanning Electron Microscope has been also reported with their performance, effect of solar energy conversion efficiency and quick response time in case of gas sensors. Prospective areas of SnO₂ research for photovoltaic and gas sensor applications has been discussed and summarized by the authors. The obtained results will illustrate the possibilities of scheming Physical, chemical, magnetic and optical properties of SnO2 for sensing devices and photovoltaic applications.

1 illus, 3 tables, 62 ref

005139   ZHOU X, GUO X, SHKURINOV A, ZHU Y (Shanghai for Science and Technology Univ, Shanghai- 200 093, People’s Republic of China, Email: xgguo_sh@qq.com) : Concentric-ring-grating-induced strong terahertz near-field enhancement on a micro-tip. J Opt 2019, 21(10), 105005.

A terahertz near-field source, composed of a subwavelength metallic concentric ring grating on a dielectric slab with a micro-tip, is proposed. The field enhancement property and the field distribution near the tip apex are studied theoretically. A volume-averaged energy density enhancement factor of 550 around the tip apex region could be obtained for radial polarized field illumination. Compared with conventional scanning near-field optical microscopies (SNOMs), about 15-fold enhancement of near-field energy density is obtained by using the proposed near-field source. We attribute such a strong enhancement to the guided resonant modes launched by the radial grating, the axial symmetry of the device, and the radial polarization of incident beam. The resonance frequencies of the device are controlled by varying the grating period and the thickness of dielectric substrate. The proposed device is useful for improving the coupling efficiency of SNOMs.

5 illus, 43 ref

005140   ZHUANG H, XU H , KONG F, WANG Y, GAO M, LI K (Shandong Jianzhu Univ, Jinan- 250 101, People’s Republic of China, Email: zhuanghuawei@sdjzu.edu.cn) : Phase-coupled plasmon-induced transparency and slow light in graphene stub detuning structures. J Opt 2019, 21(10), 105004.

Tunable phase-coupled plasmon-induced transparency (PIT) and slow light are investigated theoretically and numerically by cascading two stub resonators with a certain distance along the graphene bus waveguide. The theoretical model is analyzed by the coupled mode theory and transfer matrix method. The transmission and slow light effects in the transparent window can be tailored not only by changing the detuning of the two stub resonators but also by adjusting the separation distance L or chemical potential between the two stubs. In addition, multiple PITs and slow light are proposed and simulated with a triple-stub structure. By the numerical simulation, a conclusion is drawn that the added phase coupling can trap the SPPs in the waveguide with longer time, resulting in the slow wave effect more obviously than that with only the detuning coupled method. The proposed slow light structure will pave another way towards dynamic controlling slow light in the terahertz and mid-infrared regimes

6 illus, 41 ref

005126   LI C, ZOU J, ZHANG J, XU W, GUO C, LIU K, YUAN X, QIN S, ZHU S (National Univ of Defense Technology, Changsha- 410 073, People’s Republic of China, Email: zzhwcx@163.com) : Hybrid magnetic plasmon resonance induced tunable half-wave plate based on graphene-dielectric-metal structure. J Opt 2019, 21(10), 105003.

We propose a terahertz half-wave plate composed of a periodic array of rectangular-shaped metal-dielectric-graphene (RMDG) sandwich structure on a dielectric substrate supported by a thick metallic film. The role of graphene sheet is to combine with the rectangular-shaped metal to provide tunable anisotropic hybrid magnetic plasmon resonance. The results reveal that about 90 % of energy of the incident linearly polarized light at a certain frequency is converted to the perpendicular polarization direction after reflection from the wave plate. The high energy polarization conversion efficiency is attributable to the fact that the electric vector of the hybrid magnetic plasmon resonance in RMDG is mainly perpendicular to the graphene sheet and the absorption loss of graphene is suppressed. The half-wave plate we demonstrate here, consisting of nanostructured metal and non-structured graphene, utilizes mature metal nanostructure preparation process and avoids the graphene processing, which consequently facilitates the fabrication and promotes the application of half-wave plate.

12 illus, 1 table, 49 ref

005130   RI S, WANG Q, XIA P, TSUDA H (National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, Email: ri-shien@aist.go.jp) : Spatiotemporal phase-shifting method for accurate phase analysis of fringe pattern. J Opt 2019, 21(9), 095702.

High accurate phase analysis of waveforms as fringe patterns is essential for a wide range of scientific and engineering disciplines. However, precise phase analysis under extremely low signal-to-noise conditions is a challenging task for conventional phase-shifting methods. Here, a novel accurate phase recovering technique, called the spatiotemporal phase-shifting method (ST-PSM), is developed to measure the phase information robustly by utilizing two-dimensional intensity data in spatial- and temporal-domains simultaneously. Our simulation results indicated that ST-PSM had strong tolerance to random noise, and a self-neutralizing function to eliminate the periodical phase error due to the nonlinearity of detector, intensity saturation, vibration or phase-shifting error. The effectiveness was demonstrated experimentally from a non-contact shape measurement in fringe projection profilometry under extreme underexposure and overexposure recording conditions. Furthermore, by incorporating modern GPU parallel computing technology, a 4-step phase-shifted fringe pattern with 8 K image size can be calculated within one second. Due to its robustness and high accuracy with a fast calculation, therefore, we believe this technique has a significant impact on a variety of research and scientific fields.

8 illus, 1 table, 32 ref

005127   LI H, YAN K, ZHANG Y, DONG Z, GU C, YAO P, XU L, ZHANG R, SU J, ZHU Y, ZHAN Q (Optics and Optical Engineering Dep, Science and Technology of China Univ, Hefei- 230 026, People’s Republic of China, Email: xulixin@ustc.edu.cn) : Passively Q-switching cylindrical vector beam fiber laser operating in highorder mode. J Opt 2019, 21(9), 095502.

We experimentally demonstrate a linear-cavity all-fiber passively Q-switching cylindrical vector beam (CVB) laser operating in high-order mode. This CVB fiber laser operates without any mode converter which always leads to high insertion loss, and it can realize high efficiency. In this fiber laser, the stable Q-switching pulse is achieved with a slope efficiency of 39 %. By properly adjusting the polarization controllers, radially polarized and azimuthally polarized beams can be obtained. Our work proves the feasibility of achieving the stable Q-switching CVB pulse with high-order mode directly oscillating, and it may have an enormous potential for enhancing the efficiency.

6 illus, 24 ref

005135   WANG H, SONG Q, ZHENG S, LIN Q, WU E, AI Y, LIU C, XU S (Chinese Academy of Sciences, Shanghai- 201 800, People’s Republic of China, Email: chpliu@siom.ac.cn) : Terahertz-mid-infrared anisotropic vortex beams generation via few-cycle vortex-laserinduced air plasma. J Opt 2019, 21(9), 095501.

We numerically demonstrated the generation of terahertz-mid-infrared (THz-MIR) anisotropic vortex beams from few-cycle vortex-laser-induced air plasma based on both the intra-pulse fourwave mixing and the photocurrent models. It is found that for the low-frequency THz components, their phase variance on the azimuthal angle follows a simple stepwise increase with a step of π, indicating the unsuccessful inheritance of the orbital angular momentum (OAM) from the few-cycle vortex driving laser. However, for the high-frequency MIR components, they are anisotropic vortex beams with a nonlinear variance in the phase profile showing angular acceleration, which indicates they carry OAM. Also, their intensity distributions vary from two petal structure slowly to ring-shaped structure as the frequency increases. Physically, the behaviors of their phase and intensity distributions can be explained well by the interference theory of the two models. Interestingly, according to the fitting formula of the phase distributions, the calculated topological charges (TCs) of all components in the THz-MIR frequencies range are equal to that of the driving laser. Moreover, the phase nonlinearity and the intensity distributions strongly depend on the corresponding THz-MIR frequencies. The results from both schemes are the decoupling of the OAM, the TC, the geometry and the power distribution in anisotropic vortex beams.

5 illus, 37 ref