Asian Journal of Research and Reviews in Physics

A statistically driven spectral method was carried out on 3D seismic data and well logs in ‘’VIC’’ Field within the Niger Delta with the aim of deriving reservoir properties and delineating stratigraphic features using edge detection attributes like coherence so as to have a better and clearer view of subsurface structure of a reservoir interval that possesses hydrocarbon using Spectral method.

A suite of data consisting of seismic sections and composite logs comprising Gamma-ray, Resistivity, Spontaneous Potential, Sonic Time and Porosity logs (density and Neutron) were utilized to identify reservoir interval on log signature across wells 4 and 5 and the reservoir interval obtained was between 11,164 feet and 11,196 feet. Edge detection attribute like coherence was computed from the amplitude data in time domain and transformed to frequency domain using Fourier Transform tool in MATLAB. In order to display well log in time, well to seismic tie was carried out using check shot data which was used as time to depth relationship.

The analysis of the spectral domain shows distinct bright spots that vary with measured depth due to variation in fluid and formation properties. The results led to an enhancement of seismic data interpretation in the field of study due to a spectral technique method that was applied to calculate the frequency slices. The results indicate that the spectral domain in coherence attributes revealed better geological features and the reservoir character such as faults and fractures.

Frequency domain gives better geological maps as it is used to filter data, which means it is an enhancement of hidden features in time domain and gives a smoother variation of the features that has low frequency values. A reservoir with low frequency values is a sandy environment showing stratigraphy features. Hence, the reservoir is suspected to be a channel fill reservoir. This implies that Spectral domain (frequency) defines major geological areas of the ‘’VIC’’ field and gives much clearer image of the reservoir features within the field than in time domain.

The measurement of magnetic field intensity within Captain Elechi Amadi Polytechnic, Rumuola was carried out with the aid of a handheld Bentech (GM-3120) Model Electromagnetic Radiation Metre. A total of 6 sampled locations were recorded; randomly with six distinct measurement and their coordinates at each of the sampled location with the aid of the global system position satellite (GPS) device. The measurement took place between 2017 November to 2018 March. A minimum value of 0.3417 0.65 T was recorded at the Administrative Block and a maximum value of 1.9767 1.43 T at the Business Centre. The overall mean values of all the sampled locations all fall below the recommended limit for the outdoor magnetic field intensity exposure of 100T of the International Commission of Non-Ionizing Radiation Protection (ICNIRP). The outcome of the measurement reveals that the exposure to magnetic field intensity to staffs, students and commercial workers within the campus of the Captain Elechi Amadi Polytechnic poses no health hazard.

In this paper, the generalized KP-BBM equation is considered. The G′ / G-expansion method and the first integral method are applied to integrate the equation. By means of the two methods, the rational solutions, the periodic solutions and the hyperbolic function solutions are thus obtained under some parametric conditions.

In the current paper we tackle the task of determining the formula for the cyclotron radiation as measured from a frame co-moving with the particle being accelerated. In the case of cyclotrons, as opposed to synchrotrons, the magnetic field is constant, resulting into spiral trajectories for light particle, like electrons and into circular trajectories for heavier particles, like protons, as we will demonstrate in the current paper. This due to the fact that the braking force is a very small percentage of the accelerating (Lorentz) force, as will be shown later in our paper. These proofs have never been attempted before owing to the difficulty of dealing with rotating frames. Our paper is divided into two main sections, the first section deals with cyclotron radiation measured in the inertial frame of the lab, the second section deals with cyclotron radiation as measured in a frame co-rotating with the particle along a circular path, at a uniform speed.

The aim of this present study is to collect soil samples and some commonly consumed food materials in Ondo State, Nigeria such as tubers (cassava, Manihot esculent and yam, Dioscorea alata) samples and vegetables (waterleaf, Talinium triangulare and bitter leaf, Vernonia amygdalina) samples at some selected locations in Okitipupa, Ondo state, Southwestern, Nigeria in order to determine the following natural radionuclides (⁴⁰K, ²³⁸U and ²³²Th) levels using a well calibrated NaI(TI) which is well shielded with a detector coupled to a computer resident quantum MCA2100R Multichannel. The transfer factors, annual absorbed dose rate and the annual effective dose in the samples collected were estimated.

The results showed that the measured natural radionuclides were present in the mean concentrations of 323.79 ± 12.45 Bqkg^-1, 81.87 ± 45.30 Bqkg^-1 and 57.62 ± 18.04 Bqkg^-1 for ⁴⁰K; 11.76 ± 36.03 Bqkg^-1, 4.67 ± 10.12 Bqkg^-1 and 3.45 ± 2.10 Bqkg^-1 for ²³⁸U and 9.66 ± 0.89 Bqkg^-1, 3.07 ± 2.45 Bqkg^-1  and 2.45 ± 0.92 Bqkg^-1  for ²³²Th for soil, yam and cassava samples respectively. The results also showed that the radionuclides were present in the concentrations of 11.76 ± 36.03 Bqkg^-1 and 9.66 ± 0.89 Bqkg^-1 for ⁴⁰K; 9.67 ± 8.53 Bqkg^-1 and 7.87 ± 1.89 Bqkg^-1 for ²³⁸U and 8.63 ± 6.08 Bqkg^-1 and 6.58 ± 0.76 Bqkg^-1 for ²³²Th for waterleaf and bitter leaf samples respectively. The soil-to-yam transfer factors were found to be 0.26, 0.40 and 0.32 for ⁴⁰K, ²³⁸U and ²³²Th and soil-to-cassava yam transfer factors were found to be 0.18, 0.29 and 0.25 for ⁴⁰K, ²³⁸U and ²³²Th respectively. The soil-to-waterleaf transfer factors were found to be 0.37, 0.82 and 0.82 for ⁴⁰K, ²³⁸U and ²³²Th while the soil-to-bitter leaf transfer factors were found to be 0.32, 0.74 and 0.68 for ⁴⁰K, ²³⁸U and ²³²Th respectively.

The mean absorbed dose rate was 25.08 ± 0.57  and the mean annual outdoor effective dose was 46.17 . The annual effective dose reported for this present study area represents 65.95% of the world average value of 70.00 and 47.11% of Nigeria value of 98.00 mSvy^-1