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〖Coexistence of superconductivity and Spindensity wave in ferropnictides Ba〗_(1-x) K_x 〖Fe〗_2 〖As〗_2
The study of spin-density-wave (SDW) and superconducting order parameter is a core topic for research on the FeAs-based high Tc superconductors. By using mathematical model Hamiltonian for the system and Green’s function formalism (creation and annihilation operators), we have obtained expressions for superconducting transition temperature (TC), spin density wave transition temperature (Tsdw), superconductivity order...
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Designing off-grid hybrid energy suply with photovoltaics in Senegal
In Africa electrification rates of the rural areas are low and off-grid power supply is needed. Often diesel generators are used to provide local electricity supply. However, the tremendous decrease of the costs of photovoltaics provides an attractive option to substitute existing diesel generation or to build up a new electricity supply in those locations, lowering power costs and environmental impact. Photovoltaics (PV)...
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The level of noise exposure to daily road side traders at five major roundabouts in Ibadan metropolis has been assessed.. Noise measurements were made using a precision multi-function sound level meter. Measurements were made at three different periods of the day; morning (7:30 – 11:30 a.m.), afternoon (12:00 – 3:00 p.m.) and evening (4:00 – 5.00 p.m.) for a consecutive period of ten days. The highest mean maximum noise...
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A study to assess the outdoor Background Ionizing Radiation “BIR” levels in Emene industrial layout of Enugu state, Nigeria has been conducted. An in-situ measurement of BIR exposure rate in mRh-1 for 30 locations was done using a well calibrated portable GQ GMC-320 PLUS nuclear radiation detector at an elevation of 1.0 m above ground level with a GPS for geographical location. The measured BIR exposure rates were used to...
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The signatures of the geoeffectiveness solar disturbed events on the Magnetosphere Convection Electric Field (MCEF) universal time variation from 1964 to 2009 are investigated. We focus our attention on the periods concerned by the whole shock activity and by the different types of the geoeffectiveness Coronal Mass Ejections (CMEs) which are one-day-shock, two-days-shock and three-days-shock. The investigation is made with...
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A TECHNIQUE FOR DETERMINING EFFICIENCY OF AEROSOL SAMPLER
Viscosity, an important aspect in air flow at the lowest layer of the atmosphere was determined during Harmattan period as 1.88 x 10-5 Nsm-2 ± 0.04%. Kinematic viscosity, another important parameter on atmospheric motion was established as 0.54 x 10-5 m2s-1 ± 0.02%. For contribution to protection of human and ecological systems from dangerous levels of air pollution, a new technique for determining the efficiency of...
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Mathematical Modeling and Numerical Simulation for the Formation Process of Nanofilms
In this study we have applied a generalized model to describe and to optimize the formation process of nanofilms from their polymeric solutions. Through this model, one can optimize the concentration of the solvent in the polymeric solution, the appropriate geometric dimensions as well as the nanofilm formation speed. A comparison of this model with experimental data has revealed some similarities and differences in the...
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Er3+ -doped CaSO4-P2O5 glasses with successive increase in Er2O3 contents (from 0.1 to 0.9 mol %) were prepared using melt-quench method aimed to improve their chemical stability and optical behavior. The structure was investigated using FT-infrared and Raman spectroscopy. Non-crystalline phases were detected by X-ray diffraction (XRD) spectroscopy. From the Raman spectra, Qi were identified (i = 0, 1, 2 and 3) stands for...
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During geomagnetic storms, the geomagnetic H component is depressed which is preceded by a sudden storm commencement (SSC) or not and this is categorized as sudden or gradual storms. Using the method of cross correlation analysis, we have studied the associations of four low latitude stations at longitudinal separations of 145° - 215° with solar wind density and interplanetary magnetic field (IMF) B during four intense...
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This research was conducted with an aim of mapping the extent of subsoil and ground water contamination within the area. The contamination was as a result of an oil pipeline leakage that had gone undetected for some time and whose effects were evident on human and animal health, and crop yield. The leakage was more pronounced at possible recharge zones i.e. in thick sediments of volcanic origin (olivine basalts) and river...
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Modeling and simulation of a high-pressure polyethylene tubular reactor
The complex world of polymerization has become an important topic for research due mainly to the great investments it demands and the difficulty in operation of the huge plants that exist to produce polymers. Many papers have been written about this, most of them focusing on the reactor performance and its stability. In the present work, a model and simulation for the high- pressure polyethylene tubular reactor has been...
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This study aimed at estimating the depth to magnetic source bodies in Lafia and Akiri areas which falls within the middle Benue trough, Nigeria. Aeromagnetic data were used and Spectral Analysis and Source parameter imaging were employed in the quantitative interpretation of the data. The total magnetic intensity (TMI) contour map obtained from gridding of the data ranges from -39.5 to 100.0 nT was separated into regional...
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Structural, Magnetic and Transport Properties of Samarium (Sm) Doped Cu-Zn Ferrites
The present work is focused on investigating the effect of rare earth ion on structural, magnetic and transport properties of (Cu0.5Zn0.5Fe2-x)SmxO4[x = 0.00, 0.05 and 0.10] ferrites which were prepared by solid state reaction technique at 1100oC for 3 hours. The X-ray diffraction analysis revealed that rare earth free sample shows formulation of single phase cubic spinel structure with no extra peak whereas Sm substituted...
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The solutions of spin and pseudospin symmetries with Trigonometric scarf potential are obtained in the presence of a new tensor interaction which breaks down the energy degeneracies in both symmetries leading to atomic stability. The nonrelativistic equation is obtained by taking the nonrelativistic limit of the spin symmetry. A simplified condition for energy equation for Formula method for special case is also given....
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Feasibility analysis of hybrid electricity generation system by HOMER for Mauritanian northern coast
The reported work was motivated by the energy needs in the Mauritania region and the utility of the search features of a software system, named HOMER (Hybrid Optimization of Multiple Energy Resources), for feasibility analysis of a hybrid power generation system (HS) for the Mauritanian northern coast. This study analyzed a sample of the available wind resources to meet the energy needs of these localities, using the HOMER...
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Laplace decomposition method for Whitham-Broer-Kaup shallow water waves equations
In this paper, the Laplace decomposition method was applied to find travelling wave solutions of the Whitham-Broer-Kaup (WBK) system. To illustrate the capability of the approach, two numerical examples are given where the propagation and the error of the obtained solutions are shown in comparison of its exact solution. The approximate solutions are calculated in form of convergence power series with easily computable...
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This work studied the comparative analysis of meteorological parameter (temperature, solar radiation and relative humidity) of satellite and Nigerian Meteorological Agency (NIMET) data at Kano, Kaduna, Owerri and Sokoto for 2006, 2007, 2008, and 2010, respectively. Statistical tools of mean bias error (MBE), root mean square error (RMSE) and correlation coefficient (r) were determined to validate the data. The results...
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Solutions of partial differential equations are of great importance for mathematicians and scientists. In this paper, the author likewise calculated exact Langrage multiplier and it progressively connects to the definite results of Helmholtz and nonlinear parabolic equations. This study shows the advantages of exact Lagrange multipliers and their coupling with Variational Iteration Method. Computational work shows that the...
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Analysis of long-term rainfall trends over Nigeria
Monthly mean of rainfall data (mm) between January to December for the period 1901 to 2006 for 23 stations (grid points) over Nigeria were analyzed in this study. The trends of rainfall over the 23 stations were examined statistically based on the time series, mean, standard deviation of the rainfall data. The study period were sub-divided into 30-year Climatic means and compared with World Meteorological Organization...
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Effect of Eddy diffusion on atmospheric electrical processes in a fair weather environment
Most of the past studies have been concentrated towards the average current that flows from the thunderstorm into the global electric circuit, the role of equalization layer, and the variations of electric field for maintaining the ionosphere’s electric potential difference in the atmosphere, which are directed downward between the equipotential surfaces of the ionosphere and ground. The analytical relation for both the...
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This study investigates the seasonal variations of rainfall and its decadal anomaly over Nigeria and the possible role of solar and geomagnetic activities. Sunspot number and geomagnetic aa index were used as solar indices. Monthly mean daily rainfall data from Nigeria Meteorological (NIMET) Agency was used in this study. Descriptive, bivariate, and power spectral density (PSD) analyses, as well as Mann-Kendall trend test...
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Preparation and characterization of Holmium doped borate glass
Holmium doped borate glasses were prepared by conventional rapid melt-quench method. The X-ray powder diffraction (XRD) pattern indicates the amorphous nature of Holmium doped borate glass. Photoluminescence spectrum gives an idea of the optical properties of Holmium doped borate glass. Determination and differentiation of the various vibrational modes were done using Fourier transform infrared spectroscopy (FTIR)...
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2,3-Dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonohydrazide and its derivatives were synthesized and characterize by IR, 1H-NMR, 13C-NMR and mass spectrometry analytical methods. The 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl hydrazide (compound 1), was synthesized from the reaction of o-phenylenediamine with oxalic acid to obtain quinoxaline-2,3-dione, which was subjected to chlorosulfonation with chlorosulfonic...
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Atmospheric Physics is a fascinating scientific discipline, presents a comprehensive coverage of global meteorology and climatology. It has provided essentially a viable means for tackling environmental issues, key to vital and challenging problems facing weather and climate predictions. This Paper discusses a basic understanding of atmospheric physics as an essential field behind issues of current concern on climate...
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Nickel–titanium shape memory alloys (NiTi) are relatively special group of metallic biomaterials. Extraordinary properties of NiTi shape memory alloys are widely employed in medical applications (orthopedics, orthodontics, urology, etc.) owing to their desirable properties, such as superelasticity, relatively low modulus and good corrosion resistance. Furthermore, toxicity and carcinogenesis of Ni ions released from NiTi...
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In this paper, we report the measurement of impedance spectroscopy for the bis(2-amino-4-methylpyridinium) tetrachloridozincate (II) compound in the frequency range 209 Hz to 5 MHz with the temperature ranging from 308 up to 368 K. The impedance plots have shown semicircle arcs at different temperatures and an electrical equivalent circuit has been proposed to explain the impedance results. Detailed analysis of the...
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The possible hazardous health effects of exposure of humans to electromagnetic radiations (EMR) emitted from mobile phone base station has caused concern to the general public. The concerns on the perceived negative effects of EMF radiations from mobile phone base transceivers led to agitations against the erection of base transceiver stations (BTS). Therefore, the measurement of levels of electromagnetic field (EMF)...
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Plastics: The good, the bad and the ugly
Plastics’ demand and consumption is on the increase since 1950s due to their unique properties. Their high use coupled with challenges in end-of-use handling and their inherent resistance to degradation has led to their accumulation in the environment, which is a matter of grave concern. This review presents a general overview of the state of knowledge of the diverse faces of plastics with special reference to...
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The structural properties of composites ZnS1-xCux thin films prepared by laser ablation
The prepared samples of thin-film composite by laser ablation method were achieved. Powders of zinc slfide with copper of weight ratios x=0, 0.2, 0.4, 0.6, 0.8wt% were mixed and then compressed by approximately 10 t. The samples were ablated by using Neodymium-YAG laser with 1000 mJ and 700 pulses obtained the plasma plume at 10-5 m bar pressure and 250°C. Results were indicated using X-ray diffraction (XRD), atomic force...
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Mathematical models used in the prediction of deaths due to fire accident in Taraba State, Nigeria
This research is concerned with the application and comparison of mathematical models for predicting deaths due to fire accident in Taraba State. This research was carried out because it was observed that whenever fire accident occurs, it claims lives and properties. Data were collected for the period of ten (10) years from 2005 to 2014 from Fire Service Board, Jalingo, Taraba State, Nigeria. Various models, such as...
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Characterization prime and weakly prime left ideals in near left almost rings (nLA-rings)
The purpose of this paper was to introduce the notion of weakly prime left ideals in near left almost rings by studying, prime and weakly prime left ideals in near left almost rings (nLA-rings). Those are extended from prime and weakly prime ideals, respectively. Some characterizations of prime and weakly prime left ideals are obtained. Moreover, the relationships between prime and weakly prime left ideals in nLA-rings...
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In this research, the effects of the Ni-doped, single vacancy (SV), double vacancy (DV), stone wells (STV) defects and electric-field (EF) on the adsorption of NH3 molecules on the surface of graphene are investigated by using the first-principles calculation. For this purpose, at first step we consider different configurations models, and then all selected models are optimized for this study. From optimized structures the...
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Regression methods in the presence of heteroscedasticity and outliers
It has been observed over the years that real life data are usually non-conforming to the classical linear regression assumptions. One of the stringent assumptions that is unlikely to hold in many applied settings is that of homoscedasticity. When homogenous variance in a normal regression model is not appropriate, invalid standard inference procedure may result from the improper estimation of standard error when the...
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Risk assessment of exposure to heavy metals in drinking water in Kilimambogo, Kenya
It is very crucial for man to use clean water for drinking, domestic use, agriculture, food production or other purposes, since it has a great impact on health. The concentration levels of Cu, Cd, Mn, Fe, Ni, Pb and Zn in borehole and surface water of Kilimambogo region were measured using the atomic absorption spectrometer (AAS). pH of the water samples was also measured on site using a digital pH standard meter. The...
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Ex-vivo transdermal delivery of Annona squamosa entrapped in niosomes by electroporation
Reactive molecules derived from molecular oxygen and free radicals are commonly known as Reactive Oxygen Species (ROS). These molecules have been suggested to produce oxidative stress in cells leading to many pathological problems like diabetes, cancer, inflammation, neurodegenerative disorders, and aging. Antioxidants can remove free radicals from the human body. Therefore, it is of remarkable interest to increase the...
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This paper presents the design of a narrowband pass unequal power divider using double splintered rectangular ring shape coupled lines. The substrate material used between the power divider and the ground is of Rogers RT 5880 (lossy) with a relative permittivity of 2.2. The shape used in design makes the power divider more efficient. The device works at 5.9 GHz with the insertion loss of -3.4 dB at one port and -5.02 dB at...
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Liquid-liquid extraction of Zr(IV) from sulphuric acid medium using tri-n-octyl amine in kerosene
The extraction behaviour of Zr(IV) with tri-n-octyl amine (TOA) in kerosene has been studied through a novel method solvent extraction. The mechanism of extraction and the species extracted have been identified. Quantitative extraction of Zr(IV) with TOA was achieved in kerosene by changing different parameters such as acid variation, diluent effect, metal concentration variation, extractant variation, effect of chloride...
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Electro-generated low-band-gap conjugated polymer based on Benzothidiazole
Poly (4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,1,3-benzothiadiazole) (PBEDT) a novel low – band – gap polymer has been synthesised by electro-polymerisation of a trimer composed of precursors ethylenedioxythiophene combined with 2,1,3-benzothiadiazole. The Ultraviolet–visible (UV-V) is spectrum of the trimer in chloroform solution gave two absorption bands with peaks at 323 nm and another at 482 nm with an onset...
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In this work, the authors study the influence of the Reynolds number on the heat and mass transfers in an interface air- water of a parabolic pond of retention full of water in forced convection. The free surface of the pond is crossed by a forced warm air. In the water, the vorticity-stream function is adopted. To resolve the equations in the air which are constituted by a mixture dry air and of steam, the hypotheses of...
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In this work, we handle the space – time fractional of classical Drinfeld's Sokolov – Wilson system, the fractional (2+1) – dimensional Davey–Stewartson system and the fractional generalized Hirota- Satsuma coupled KdV systemto solve analytically. Firstly, we use fractional traveling wave transformations to convert fractional nonlinear partial differential equations to nonlinear ordinary differential equations. Next,...
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We apply the two-variable )--expansion method to construct new exact traveling wave solutions with parameters of the nonlinear potential Boussinesq and ZKBBM equations. This method can be thought of as the generalization of the well-known )---expansion method given recently by Wang and co-workers (2008). When the parameters are replaced by special values, the well-known solitary wave solutions of this equation are...
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