Open Access Original Research Article

Comparison of Iron Plasma Atomic and Radiative Properties Computed with a Relativistic Collisional Radiative Average Atom Code versus Other Models

A. J. Benita

Asian Journal of Research and Reviews in Physics, Page 1-35
DOI: 10.9734/ajr2p/2018/v1i224599

In this paper, it is presented a representative sample of steady state iron plasmas focusing the attention on two issues. First, the huge computation capability extension up to millions of plasmas with the implementation of a collisional radiative balance in the relativistic average atom model ATMED. Second, it will be addressed the good agreement of atomic and radiative properties not only with respect to very recent experimental measurements of laboratories and High Energy Density facilities, but also to the last theoretical developments in quantum mechanics of statistical methods, as new codes based on the self consistent Hartree-Fock-Slater model for the average atom which in turn solve the Schrödinger’s or Dirac’s equations of radial wave functions. The new codes have been validated with some state of the art models as OPAL, SCO-RCG, STA, CASSANDRA, LEDCOP, THERMOS, etc.

The results for plasma properties can be considered as relatively precise and optimal, being checked fundamentally the high sensitivity of calculations to changes in regime, local thermodynamic equilibrium (LTE) or non-LTE (NLTE), electronic and radiation temperatures, dilution factor, matter or electronic density and plasma length. The systematic theoretical investigation is carried out through comparison of calculations performed with a wide set of atomic collisional radiative codes with detailed configurations or codes of the average atom formalism. Some transmissions computed with ATMED CR using UTA (Unresolved Transition Array) formalism are also checked with respect to very recent experimental measurements of laboratories.

 

Open Access Original Research Article

Electronic Behaviour of Schottky Diodes Fabricated from Electroplated CdSe Semiconductors

O. I. Olusola, T. Ewetumo, T. A. Obagade, K. D. Adedayo

Asian Journal of Research and Reviews in Physics, Page 1-8
DOI: 10.9734/ajr2p/2018/v1i224603

The fabrication of Schottky diodes using electroplated n- type CdSe thin films and gold metal contact have been successfully achieved. The electronic properties of the fabricated diodes with the device structure glass/FTO/n-CdSe/Au have been investigated by current-voltage (I-V) and capacitance-voltage (CV) measurement techniques. The I-V characteristics revealed a good rectifying behaviour with an ideality factor of 1.50, a potential barrier height (ϕb) >0.79 eV and rectification factor (RF) surpassing 102 at 1.0 V. Results from the C-V measurement showed that the fabricated Schottky diodes have doping density of ~1.61 × 1017 cm-3 and a built-in potential (Vbi) of 0.24 V which falls in the range of reported Vbi values for Schottky diodes. Both I-V and C-V parameters revealed that the CdSe Schottky diodes possess qualities for excellent performance in electronics circuit or as an electronic device.

 

Open Access Original Research Article

Evaluate the Radioactivity in Drinking Water from Kakuri, Kaduna

Tajudeen O. Adeeko, Lilian E. Adeeko

Asian Journal of Research and Reviews in Physics, Page 1-8
DOI: 10.9734/ajr2p/2018/v1i224605

Small traces of radioactivity are normally found in all drinking water. The concentration and composition of these radioactive constituents vary from place to place, depending principally on the radiochemical composition of the soil and rock strata through which the raw water may have passed. The aims of this work were to analyze and determine the gross concentration of alpha and beta radiation in drinking water. Ten water samples from hand-dug (HD) well (5) and borehole (BH) (5) were selected applied stratified random sampling technique from kakuri. Results of the measurements reveal that gross alpha and beta activity were presence in all the water samples investigated; the gross alpha activities range between 0.014±0.006Bq/l to 0.072±0.022Bq/l, with average of 0.037±0.014Bq/l, and gross beta activities range between 0.200±0.041Bq/l to 1.530±0.140Bq/l, with average of 0.6132±0.104Bq/l. The hand-dug well and borehole were not radioactively contaminated, the obtained values were all below the World Health Organization (WHO) and International Organization on Standardization (ISO) drinking water guideline values of 1.0Bq/l for gross beta radioactivity and 0.5Bq/l for gross alpha radioactivity per year. Hence, groundwater from the area is radioactivity safe to use, it posed no threat to the health of people around the area when consumed, besides transformer borehole (BH08) sample which exhibit high beta activity, therefore; borehole (BH08) sample is not drinkable because it’s not safe of radioactivity.

 

Open Access Original Research Article

Evaluation of Energy and Density of States of Two Dimensional Quantum Structure (Quantum Well)

J. Ilouno, I. J. Audu, M. Y. Mafuyai, N. Okpara

Asian Journal of Research and Reviews in Physics, Page 1-6
DOI: 10.9734/ajr2p/2018/v1i224608

Quantum structures (e.g. quantum wells) are a critical part of optical system designs (lasers, modulators, switches etc.). In the quantum well, the motion of the particle is quantized in one direction while the particle moves freely in other two directions. The density of state of the quantum structure is the possible number of state an excited electron can occupy per unit volume. The density of state depends on the energy at which the electron moves when excited. In this paper, the energy and density of states of two-dimensional quantum structure (quantum well) were calculated. The results obtained revealed the density of state increases with the energy but exhibited maximum and minimum peaks. Maximum peaks occurred at 4 eV and 7.5 eV while the minimum peaks occurred at 5 eV and 8 eV. These show that energy of state for quantum wells neither varies linearly nor exponentially with a density of state because of high energy level. The findings are in agreement with published literature. Some applications of quantum wells include: bioconjugates, solar cells, photovoltaic, photo and electrochromic devices etc.

Open Access Original Research Article

Gamma Spectrometry Analysis of Natural Radionuclide Contents of Three Mushroom Species Commonly Grown in Benue State, Nigeria

A. A. Nathan, T. Sombo, B. V. Gurgur, A. A. Avaa, T. A. Fadeyi

Asian Journal of Research and Reviews in Physics, Page 1-8
DOI: 10.9734/ajr2p/2018/v1i224610

The activity concentration and Annual Effective doses of 40K, 226Ra, and 232Th in some edible mushroom species (Cantharellus cibarius, Agaricus campestris, Termitomyces robustus) found in three Local Government Areas of Benue state-Nigeria were determined using Gamma Spectrometry; the 1460KeV gamma-radiation of 40K was used to determine the concentration of 40K, gamma transition energy of 1764.5KeV 214Bi was used to determine the concentration of 226R, while the gamma transition energy of 2614KeV 208TI was used to determine the concentration of 232Th. The activity concentration due to 226Ra, 232Th and 40K in the samples ranged from 10.06±1.6 - 14.19±3.01Bqkg-1; 10.88±2.65 to 15.38±4.30Bqkg-1and 202.31±1.4 to 318.44±3.20Bqkg-1 respectively; the highest activity due to 226Ra was found in Termitomyces robustus grown in Gboko; that due to 232Th was recorded in Agaricus campestris grown in Buruku L.G.A., while the highest activity concentration due to 40K was recorded in Termitomyces robustus found in Buruku. Generally, 40K recorded the highest activity concentration in each mushroom species examined. Annual Effective Dose from these species sampled ranges from 0.0006952mSvy-1 (in Makurdi- Termitomyces robustus species) - 0.0008467mSvy-1 (in Buruku Termitomyces robustus species). The average effective dose value of 0.00788±0.000186mSvy-1 obtained in this work is below the maximum permissible level established by ICRP (1996). Thus, these mushrooms species will not pose any apparent risk to human health.