IOSR-JAP   Volume-14 ~ Issue-4 ~ Jul. – Aug. 2022

ABSTRACT: Polypyrrole (PPy) nano composites were synthesized by in situ polymerization technique and characterized by Fourier transform infrared spectra (FTIR), Field Emission Gun Scanning Electron Microscopy (FEG-SEM). The synthesized materials were further used for sensing of NH3 gas. The change in resistance of the material with time was recorded after the response of NH3 gas. The increase in electrical resistance is due to transfer of charge from the sensing material to the analyzed gas and absorption of gas into the polymer matrix. The sensitivity was found maximum for NH3. The PPy nano composite showed maximum sensitivity (48 %) for 400 ppm of NH3 gas.

Keywords: Conductive polymer, NH3 gas sensor, Time response

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ABSTRACT: A black hole is a region of space-time exhibiting such strong gravitational effects that nothing not even particles and electromagnetic radiation such as light can escape from inside it. In many ways a black hole acts like an ideal black body, as it reflects no light. Black holes of stellar masses are expected to form when the massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars merging with other black holes, supermassive black holes of millions of solar masses may form There is general consensus that super massive black holes exist in the centre of most galaxies.

Keywords: Black holes, massive stars,galaxy, gravitational effects, light waves

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ABSTRACT: The background radiation level of a zone refers to the total radiation from multiple sources at a certain location on the earth's surface. The energy that moves in the form of electromagnetic waves or particles is referred to as radiation. Among the several radiations: Humans are exposed to ionizing radiation, which can be harmful to their health. We were interested in high-energy radiations that could ionize matter in this work. Overexposure to ionizing radiations can cause a variety of malignancies. Radiation can come from a variety of sources, including cosmic rays (radiation from space), radiation from radioactive atoms on the earth's surface, radiation from our own bodies, and so on. 40K, 226Ra......

Keywords: Background Radiation, GM counter, Longitude, Latitude etc.

[1]. R.P.Chhetri, "Background Radiation: Detection, Measurement and Hazards," Himalayan Physics, 2017.
[2]. A. R. K. J. M. P. Abdu Hamoud Al-Khawlany, "Review on studies in natural background radiation,"Radiation Protection and Environment, p. 215, 2018.
[3]. Amazon, "Product Information 6011," Amazon.com, 2019.
[4]. A. O. M. AyorindeOgunremi, "Natural Radionuclide Concentrations and Associated Doses Around Three Dumpsites in Lagos, Nigeria," 2021.
[5]. K. F. a. M. R. E. Litvak, "Health and Safety Implications of Exposure to Electromagnetic Fields in the Frequency Range 300 Hz to 10 MHz," E. Litvak, K.R. Foster, and M.H. Repachol, vol. 23, pp. 68-82, 2002.

ABSTRACT: Perovskite solar cells (PSCs) are the newestinvestigationfield among variousmodern photovoltaic devices because of their incredibly high conversion efficiency (PCE). The PSC incorporates an ABX3 crystal structure known as perovskite structure as an active light-harvesting layer. Unlike silicon solar cells, PSCs are cheaperand also may bemanufactured using aneasy wet chemical procedure. Various investigations are currently underwayto enhancePSC's PCE to the limits of Shockley-Queisser. In addition, instability and short lifespan are other gravedangers to the PSC's commercialization. This review describes the material structure of perovskite, its applications, the properties of the best solar absorbers, the evolution of PSCs, the structure and mechanism of PSCs, challenges, and future prospects.

Key Word: Photovoltaic, Perovskite material, Perovskite solar cell, HTM, PCE

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[5]. Sun, S., Lu, M., Gao, X., Shi, Z., Bai, X., Yu, W. W., Zhang, Y.Adv. Sci., 8, 2102689 (2021)
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ABSTRACT: Background: Spacetime is one of the most important topic in physics. Scientists of many countries are researching on it since many centuries. And the cosmology are highly connected with this Spacetime. Because the birth of Spacetime is the birth of Universe.The Spacetime is just a addition of some dimensions. All of that dimensions were created by the Big Bang.From the creation of human till now we have discovered many answer of Universal problem.And many of the problem is still unsolved. One of that is time travel. Materials and methods: All of this research has done by some of calculation. That calculations have created by imagination and logic. All of that calculations are based on Spacetime......

Keywords: Spacetime Energy, dimension, creation, time travel

[1]. Relativity- Albert Einstein
[2]. Quantum Fluctuations- Werner Heisenberg
[3]. A brief history of time- Stephen Hawking

ABSTRACT: This study examined and compared20-year mean values of surface radio refractivity patterns at 6am, 12noon, 6 pm and 12 am local times in January (the peak of dry season)and July (peak of rainy season) over Nigeria using meteorological parameters from 112 gridded stations averaged over a period of 1979 – 1998 and 1999 – 2018 with a view to produce updated refractivity maps linked with surface meteorological patterns.The dataset of atmospheric temperature, T (K), atmospheric pressure, P (hPa), relative humidity, Rh (%) and rainfall, RR (mm/hour) were extracted using text import wizard and appropriate delimited options using ITU-R equations and averaged to deduce 20-years average of surface refractivity at 6am, 12noon, 6pm, and 12midnight in January and July for 40 years......

Keywords: meteorological parameters, diurnal variations, surface radio refractivity, refractivity map,

[1]. Adediji A. T., Ajewole M. (2008). Vertical profile of radio refractivity gradient in Akure Southwest Nigeria. Prog. Electromagn. Res. 14:157-168
[2]. Adeyemi B. (2004). Tropospheric radio refractivity over three Radiosonde Stations in Nigeria, Ife. J. Sci. 6(2):167-176.
[3]. Ajileye O. O., Jegede O. O., Ayoola M. A., Eguaroje O. E. and Mohammed S. O. (2014). Variations of Surface Refractivity for Different Climatic Zones across West Africa. International Journal of Scientific and Engineering Research, Vol. 5, Issue 3 (USA) pp 521 – 530
[4]. Ajileye O. O. (2016). Dependence of Surface Refractivity Gradient Variation on Precipitation in the Tropical West Africa. IOSR Journal of Applied Physics, Volume 8, Issue 3 Ver. III, PP 57-65.
[5]. Ajileye O. O., Kolawole I. S., Ogbole J. O., Alaga A. T., Halilu A. S. and Mohammed S. O. (2016). Influence of Topography on Surface Radio Refractivity Patterns over North Central, Nigeria. Physical Science International Journal, 11(3): 1-12, DOI: 10.9734/PSIJ/2016/27436.

ABSTRACT: This paper investigates the structural stability, electronic, and optical properties of MoS2 in hexagonal and trigonal phases using the first-principles method, the results show that the two-phase bulk MoS2is stable. The material has a bandgap of 1.37eV and 1.52eV in hexagonal and trigonal phases which are in agreement with the available literature and also indicated that both phases of the materials are semiconductors. The work shows the materials have a potential for use in optoelectronic applications due to their significant response to incident radiation

Keywords: DFT, Transition metal dichalcogenides, external field, chalcogen, optical properties

[1]. Du, J., et al., Strain engineering in 2D material‐based flexible optoelectronics. Small Methods, 2021. 5(1): p. 2000919.
[2]. Yang, S.-H., et al., Chiral spintronics. Nature Reviews Physics, 2021. 3(5): p. 328-343.
[3]. <Quasiparticle Band Structures of Bulk and Few-layer PdSe2 from First-principles GW Calculations.pdf>.
[4]. Guan, Z., et al., Recent Progress in Two‐Dimensional Ferroelectric Materials. Advanced Electronic Materials, 2019. 6(1).
[5]. Kumar, A. and P.K. Ahluwalia, A first principle Comparative study of electronic and optical properties of 1H – MoS2 and 2H – MoS2. Materials Chemistry and Physics, 2012. 135(2-3): p. 755-761.

ABSTRACT: The action of a magnetic field on an ordinary substance is accompanied by a decrease in the electrical conductivity of the substance. It turns out that even in an electrical system consisting of two asymmetric aluminum electrodes immersed in a pure liquid, when exposed to a magnetic field, the conductivity increases. The change in current strength in such a system is proportional to the square of the strength of the external magnetic field. As the distance between the field source and the system increases, the relative change in current sharply decreases. Temperature variations cannot explain the observed phenomenon.....

Key Word: Magnetoresistance, Magnetic Field, Voltage, Electric Current, Aluminum, Water

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[4]. Gerasimov SA Dark Electric Current in Liquid and Second Law of Thermodynamics. IOSR Journal of Applied Physics. 2021; 13(2): 53-55.
[5]. Gerasimov SA. Dark Current and Magnetic Field Liquid. European Journal of Applied Physics. 2021; 3(6): 21-24.

ABSTRACT: Tin oxide SnO2, Aluminum oxide Al2O3nanoparticles and SnO2/Al2O3 nanocomposites were successfully synthesized hydrothermally at 150oC for 24hrs. The crystalline phase, morphology and particle sizes had been characterized by X-ray diffraction (XRD) and HRTEM.It is found that the particle size of the SnO2/Al2O3 nanocompositesis........

Key words: SnO2, Al2O3 , nanocomposites

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