Open Access Short Research Article

Spectral Characteristics of the Barrier Discharge on Mercury Diiodide Vapor with Neon Mixture

Antonina A. Malinina

Physical Science International Journal, Page 1-8
DOI: 10.9734/PSIJ/2018/42211

Aims: To investigate spectral characteristics of a high-frequency barrier discharge plasma of atmospheric pressure on mercury diiodide vapor with neon mixture.

Study Design:  A small cylindrical radiator with a single dielectric barrier of capacitance Cd = 40 pF made of a quartz tube was used for the experiments. Inside along the axis there was a molybdenum electrode with a diameter 1 mm, an external electrode 30 mm in length was made of a mesh with a transmittance 70%.

Place and Duration of Study: Department of Quantum electronics, Faculty of Physics, Uzhhorod National University, between June 2017 and September 2017.

Methodology: The high-voltage generator with an average power of up to 100 W was used to apply sinusoidal voltage (up to 7 kV and 130 kHz) to the electrodes of the radiator. The radiation spectra were recorded using a Jobin Yvon TRIAX 550 spectrometer (1200 lines / mm and 3600 lines / mm, a slit 0.02 mm, a quartz optical fiber and a Spectrum ONE  CCD detector cooled with liquid nitrogen.

Results: Intense quasicontinuous emission of spectral bands with a maximum at λ = 443 nm and 306 nm, as well as 342 nm of exciplex molecules mercury monoiodide and iodide molecules have been revealed. The main part of the emission of spectral bands is concentrated in violet-blue spectral region, namely, 439-446 nm, the relative brightness of which is higher than the brightness of other spectral bands and lines.

Conclusion: The gas discharge excilamp at high pumping frequencies on mercury diiodide with neon mixture can be created with operating life higher than the excilamp, where the buffer gas is used helium.

Open Access Short communication

Entropy as a Sum of Heat Capacities

Igor A. Stepanov

Physical Science International Journal, Page 1-3
DOI: 10.9734/PSIJ/2018/41666

An attempt is made to explain the meaning of entropy in thermodynamics. A new concept of heat capacity is defined. For it, the temperature change is measured from 0 kelvin. It is supposed that the entropy of a substance is the sum of these heat capacities in the formation of the substance from 0 kelvin to the actual temperature. This conclusion agrees with experimental data.

Open Access Original Research Article

An Experimental Study to Examine the Curved Spacetime Using Magnetic Fields

C. G. Sim

Physical Science International Journal, Page 1-8
DOI: 10.9734/PSIJ/2018/40648

The curvature of spacetime represented by Einstein field equation has many physical implications, including gravity. As light is deflected by the curvature of spacetime, a magnetic field will also be influenced by the curved spacetime. A permanent magnet is generally known to maintain its persistent magnetic field on the ground as long as there is no external magnetic interference. However, a series of experiments find that there are noticeable changes in the magnetic fields distribution while the permanent magnet rotates. The magnetic field lines of the permanent magnet are deflected towards Earth’s centre, implying a possibility that we can use magnetic field, a more efficient tool than a satellite, to measure the curvature of spacetime. However, comparing the experimental results of this study with theoretically obtained values of the curvature of spacetime remains a vast area of research for future studies.

Open Access Original Research Article

An Assessment of Human Exposure to RF Radiation from Mobile Transceiver Stations in Minna, Okene and Birnin Kebi, Nigeria

M. A. Bashir, O. D. Oyedum, M. A. Tyabo, Muraina Nurudeen

Physical Science International Journal, Page 1-5
DOI: 10.9734/PSIJ/2018/38409

In the recent, there has been massive development in the use of mobile phones, especially in developing countries. But electromagnetic radiation (EMR) emissions from various mobile transceiver stations (MTS) have raised debates on whether they are hazardous to human or not. In this study, we aim at presenting an assessment of human exposure to RF radiation from mobile transceiver stations in [G1] Minna, Okene and Birnin Kebbi. The power flux densities radiations (W/m2) on residential buildings around the MTS were measured using a handheld Extech RF EMF strength meter. The highest mean power flux densities values recorded for Minna, Okene and Birnin Kebbi were 69.17 mW/m2, 42.98 mW/m2 and 37.98 mW/m2 while the least values were 2.11 mW/m2, 18.27 mW/m2 and 11.83mW/m2 respectively. The results show that the measured mean power flux densities from individual mobile transceiver stations (Minna, Okene and Birnin Kebbi) have been compared with a standard limit set by International Commission on [G2] NonIonising Radiation Protection (ICNIRP). The measured values were far below the concern limit. Therefore, RF emission from MTS in these study areas may pose no known health hazards to the general public within the chosen vicinity.

Open Access Original Research Article

Heat and Mass Transfer of a Chemically Reacting MHD Micropolar Fluid Flow over an Exponentially Stretching Sheet with Slip Effects

E. O. Fatunmbi, O. J. Fenuga

Physical Science International Journal, Page 1-15
DOI: 10.9734/PSIJ/2018/41938

This work investigates flow, heat and mass transfer of a chemically reacting and electrically conducting micropolar fluid over an exponentially stretching sheet in the presence of thermal radiation, viscous dissipation, suction/injection, heat source/sink and slip effects. The system of the governing partial differential equations of the fluid flow is transformed into nonlinear ordinary differential equations by applying similarity variables. The resulting equations are numerically solved via shooting method alongside fourth order Runge-Kutta integration technique. The influences of the controlling flow parameters on the dimensionless velocity, angular velocity, temperature and species concentration profiles as well as on the skin friction coefficient, wall couple stress coefficient, heat and mass transfer rates are presented through graphs and tables. Comparison of the present results with previously published work in the literature for some limiting cases shows a good agreement.