Open Access Technical Note

MODFLOW’s River Package: Part 1: A Critique

Hubert J. Morel-Seytoux

Physical Science International Journal, Page 1-9
DOI: 10.9734/psij/2019/v22i230129

Most widely used integrated hydrologic models were conceived and their development started some 50-60 years ago.  These models have undertaken many major improvements since. However they still describe the flow interaction between streams and aquifers using the primitive early concepts. Most users seem unaware of the limitations of these concepts, which use parameters that are empirical and can only be obtained by calibration.  In this Part1 the shortcomings of the methodology are shown in great details. In the article reference is made specifically to the code MODFLOW.  Most of the other integrated hydrologic models used for large-scale regional studies apply essentially the same methodology to estimate seepage.

In a second Part means are presented by which improvements can be introduced in the procedures.

Open Access Original Research Article

Financial Analysis of Photovoltaic Installations in Burkina Faso

Ladifata Mogmenga, Bouchaib Hartiti, Amadou Diallo, Adama Ouedraogo, Nébon Bado, S. Fadili, P. Thevenin, Joseph Dieudonné Bathiebo

Physical Science International Journal, Page 1-13
DOI: 10.9734/psij/2019/v22i230125

This article focuses on the economic and financial calculations concerning the production of electrical energy from photovoltaic installations connected to the grid. The estimation of energy production is done in fifteen cities in Burkina Faso. Among these localities, ten cities are homes to synoptic stations. The economic return in terms of the return on investment of the electricity production from PV installations is calculated by using the method of budgeted capital. The cost of the energy produced by photovoltaic installations during their operational lives (taken here equal to 25 years) is calculated and compared with other economic parameters. The observation shows that Gaoua records the smallest production and that the highest production is recorded in Ouahigouya. The analysis of the cash flows generated by the operation of these PV installations shows that the profits are perceptible from the 8th year in Ouahigouya and the 9th year in Gaoua. An Internal Rate of Return (IRR) of 14.42% is obtained in the locality of Ouahigouya. For locality of Gaoua the IRR is equal to13.72%. The calculation of Leveled Cost Of Energy (LCOE) gives an average value of 60 Fcfa / kWh for a discount rate of 4%. This value is almost equal to half the average price of electricity in Burkina Faso, which is 119 Fcfa / kWh.

Open Access Original Research Article

Growth and Characterization of PbTe Thin-film through Solvo Thermal Method

B. A. Ahuome, I. Adamu, M. A. Adamu, A. N. Baba-Kutigi

Physical Science International Journal, Page 1-5
DOI: 10.9734/psij/2019/v22i230126

The research considered the Solvo-Thermal method of growing PbTe on non-conducting glass substrate. Cadmium Sulphide thin-film was deposited and used as the n-type absorber layer. On the internal parameters studied, the PbTe nano-film has thickness of  as measured through gravimetric analysis; the optical absorbance studied through the use of UV-750 Series spectrophotometer showed a stable absorbance within the visible wavelength (390 nm – 700 nm) and optical band gap energy of was obtained as extrapolated from the graph of  against . The I-V pattern were measured and plotted. The PbTe grown through this method therefore show a good Fill factor of  

Open Access Original Research Article

Challenging the Greenhouse Effect Specification and the Climate Sensitivity of the IPCC

Antero Ollila

Physical Science International Journal, Page 1-19
DOI: 10.9734/psij/2019/v22i230127

The greenhouse effect concept has been developed to explain the Earth’s elevated temperature. The prevailing theory of climate change is the anthropogenic global warming theory, which assumes that the greenhouse (GH) effect is due to the longwave (LW) absorption of 155.6 Wm-2 by GH gases and clouds. The actual warming increase to 33°C of the Earth’s surface temperature according to the present GH effect definition is the infrared downward LW radiation of 345.6 Wm-2 emitted by the atmosphere. The atmosphere’s temperature is the key element behind this radiation. According to the energy laws, it is not possible that the LW absorption of 155.6 Wm-2 by the GH gases could re-emit downward LW radiation of 345.6 Wm-2 on the Earth’s surface. In this study, the GH effect is 294.5 Wm-2, including shortwave radiation absorption by the atmosphere and the latent and sensible heating effect. This greater GH effect is a prerequisite for the present atmospheric temperature, which provides downward radiation on the surface. Clouds’ net effect is 1% based on the empirical observations. The contribution of CO2 in the GH effect is 7.3% corresponding to 2.4°C in temperature. The reproduction of CO2 radiative forcing (RF) showed the climate sensitivity RF value to be 2.16 Wm-2, which is 41.6% smaller than the 3.7 Wm-2 used by the IPCC. A climate model showing a climate sensitivity (CS) of 0.6°C matches the CO2 contribution in the GH effect, but the IPCC’s climate model showing a CS of 1.8°C or 1.2°C does not.

Open Access Original Research Article

Impact of Base Station Site, Antenna Configuration and Power Control in LTE Network

Alhassan Shilo Shekwonya, Lebe Nnanna

Physical Science International Journal, Page 1-8
DOI: 10.9734/psij/2019/v22i230128

This study analyzed the impact of spatial distribution of APs/Base stations, antenna configuration and power control in a dense populated area like Owerri (Nigeria), using link planner network simulator and Google-Earth Software. High-effective data capacity at hotspots in conjunction with bandwidth and the predicted power at the receiver for LTE network are required to capture some  number of users and provide high data rates over the Wi-Fi interface. The data rates are influenced by the terrain, which loses throughput due to delays, path loss and interference. The hotspot range which determines the number of users, that can associate, is limited by the power of the client and the access point. The variables that affect link performance, such as: band, region, equipment, antenna, height, terrain and obstructions towards providing enhanced capacity and coverage are measured by the link planner. The characteristics like gain, beam, width and frequency, for evaluation of results in terms of coverage and capacity for different antenna configurations, receive-Power, terrain, bandwidth and distances are also observed respectively. The results show that pathloss increases or decreases with these factors between nodes. The strategy to place the transmitter in the highest position has also proven better performance for implementation of the LTE system and its long run operation.