Asian Journal of Physical and Chemical Sciences

Based on the Gravito-Electro-Magnetic (GEM) equations as another form (for low fields) of Einstein's Equations of General Relativity Theory (GRT) an equation is derived for the total energy density in the universe, including the gravitational fields, the contribution thereof is always negative and so it seems to represents the Dark Energy (DE).  When calculating the total energy of the universe from this equation, the result is near to zero because of negative contributions from gravitational fields, depending a little on the available parameters of the universe as e.g. it's baryonic mass. Thus the assumption is given a high amount of probability, that the total energy (mass) in the universe is really zero and very likely is always zero. This  would mean, that the universe developed from empty space-time or from nothing (may be by quantum fluctuations). Looking on the development it could be  that the average energy density is zero for each sufficient large part of the universe at any time, except for very local deviations (e.g. galaxies, black holes etc.). As a consequence the expansion of the universe is probably not retarded by gravity (thus the Friedmann equation and others do not apply). The expansion of the universe can be considered as driven by the pressure of a gas-like medium with positive masses as by intergalactic gas, dust, stars and galaxies. Conclusions are drawn as to the interpretation of the formation of voids in the universe, flat space etc.

Evaluation of indoor radon level and its health risk parameters has been carried out in three communities Azuabie, Trans-Amadi and Nkpogu towns in Port Harcourt, Rivers State, Nigeria. A pocket sized Corentium Arthings digital radon detector meter was used to record the indoor radon concentration levels. The geographical coordinates were recorded using a hand-held geographical positioning system (GPS) for the various sample points. A total of 30 sample points were evaluated, with 10 sample points for each town respectively. The results of the concentration levels showed that for Azuabie (AZ) town, the concentration level varied from 6.660 Bqm^-3 to 13.690 Bqm^-3 with an average of 10.65±0.95Bqm^-3. Nkpogu (NK) town the results of the indoor concentration level ranged from 9.250 Bqm^-3 to 18.870 Bqm^-3 with an average of 13.32±1.02 Bqm^-3, Nkpogu (NK) town, the indoor concentration level ranged from 7.030 Bqm^-3 to 20.350 Bqm^-3 with an average of 12.25±1.34Bqm^-3. The annual absorbed dose for Azuabie, Trans-Amadi and Nkpogu varied as follows, 1.680 mSvy^-1 – 3.921 mSvy^-1, 2.334 mSvy^-1 – 47610 mSvy^-1 and 1.774 mSvy^-2 – 5.134 mSvy^-1 respectively. The annual effect dose rate for the three towns ranged from 0.403 mSvy^-1 – 0.941mSvy^-1, 0.560 mSvy^-1 - 1.143 mSvy^-1 and 0.426 mSvy^-1 – 1.143mSvy^-1. The excess life time cancer risk varied from 1.4117 – 3.294, 1.9607 – 3.999 and 1.4901 – 3.999 respectively. The results of the indoor concentration levels annual and the absorbed dose and the annual effective dose rate are all below the ICRP safe limit. However, the results of the excess life time cancer risk are all higher than the ICRP safe standard limit of 0.029×10^-3.

Human are exposed to Background Ionizing radiation (BIR) due to the consumption of crops from fertilized farms within the study area.an in-situ measurement of BIR exposure rate in six fertilized farms and the unfertilized farm aws carried out using a well calibrated portable nuclear radiation detector (Digilert 200). and Geographical positioning system (GPS) for measuring the geographical location. The BIR of the selected local government area varies from 0.012 mR/hr to 0.022 mR / hr and the higher BIR value recorded in Khana, Obio / Akpor, Ahuoda east and Emuoha Local Government area (0.015 mR/hr, 0.015 mR / hr , 0.014 mR/hr , 0.014 mR / hr . While the mean value of Eleme and Gokana were within the permissible limit of 0.013 mR/hr and the BIR of the unfertilized farm was lower than the standard value of 0.013 mR/hr.the mean of absorbed dose varies from 1131 nGy / hr to 122.1nGy/hr which was higher than the recommended safe limit of 84.0 nGy / hr UNSCEAR 2008.The mean of ELCR varies from 0.63 to 0.72x10^-3 which is higher than the world average value. The AEDE varies from 0.14 to 0.33 mSv / yr which are below the recommended permissible limit of 1.0 mSv / yr for general public. The effective dose to different body organs are below the recommended limit of 1.0 mSv / yr. The study shows that fertilized farms are contaminated due consistence application of fertilizers during cultivation, but the contamination does not have any direction health effect on individual who consumed crops from fertilized farms but there is the potential for long term health hazards in future such as Cancer due to consistence consumption of crops from fertilized farms.

The petroleum industry includes the global processes of exploration, extraction, refining, transportation and marketing of natural gas, crude oil and refined petroleum products. The oil industry demands more sophisticated methods for the exploitation of petroleum. As a result, the use of oil field chemicals is becoming increasingly important and has received much attention in recent years due to the vast role they play in the recovery of hydrocarbons which has enormous  commercial benefits. The three main sectors of the petroleum industry are Upstream, Midstream and Downstream. The Upstream deals with exploration and the subsequent production (drilling of exploration wells to recover oil and gas). In the Midstream sector, petroleum produced is transported through pipelines as natural gas, crude oil, and natural gas liquids. Downstream sector is basically involved in the processing of the raw materials obtained from the Upstream sector. The operations comprises of refining of crude oil, processing and purifying of natural gas. Oil field chemicals offers exceptional applications in these sectors with wide range of applications in operations such as improved oil recovery, drilling optimization, corrosion protection, mud loss prevention, drilling fluid stabilization in high pressure and high temperature environment, and many others. Application of a wide range of oilfield chemicals is therefore essential to rectify issues and concerns which may arise from oil and gas operational activities. This review intends to highlight some of the oil field chemicals and  their positive applications in the oil and gas Industries.

This article is devoted to the study of the mechanical and water properties of concrete of         Typha australis. The concrete is achieved by the mixture cattail aggregates with cement, sand and water.

Mechanical study showed that the density and the mechanical compressive strength decreases with the dosage of typha aggregates, and increases with the dosage of cement. However, the values obtained do not allow using this concrete in supporting structures. However, the value obtained is 0.16 MPa for the first series (S1), and 0.26 MPa for the second series (S2), for a high dosage of typha of 3.5% is sufficient for a wall of three meters high can support its own load. 

With a constant intrinsic porosity, these aggregates are compressible and porous. This physical condition makes the vegetable particles of typha very lightweight and sensitive to water.

The lightweight concrete became sensitive to water. Increasing the dosage of typha aggregates increase the water absorption of concrete. More than 50% of the water content is absorbed during thirty minutes of immersion. It is therefore strongly recommended to waterproof the wall with typha australis.