Open Access Original Research Article

Simulation and Optimization of a Greenhouse-Type Solar Dryer with Comsol Multiphysics

Karidioula Daouda, Koné Kisselmina Youssouf, Kouakou Lébé Prisca Marie-Sandrine, Andji-Yapi Yao Jonas, Assidjo Nogbou Emmanuel, Trokourey Albert, Laguerre Jean-Claude

Asian Journal of Physical and Chemical Sciences, Page 1-14
DOI: 10.9734/ajopacs/2022/v10i230151

Solar drying remains for developing African countries the only economical means of preserving foodstuffs for which post-harvest losses sometimes reach 60%.

It was modeled in this work, the different elements that constitute a solar drying system by natural convection. This model is described by heat, mass and momentum balance equations between the different exchange media.

The model initially made it possible to describe the dynamic behavior and calorific value of greenhouse-type solar dryers.

The optimization study through simulations also made it possible to compare the drying power of more than 180 solar dryers. The analysis of the simulation results gave the dryer a small size (h = 2.5 m and l = 3 m) with large identical openings (inlet = loutlet = 25 cm) positioned at the two extremes: bottom for the inlet (Ye = 0.1 m) and high for the air outlet (Ys = 1.65 m), as an energy-efficient dryer (Taverage = 50.73 oC). The fluidity of the air (Vaverage = 0.58 m.s-1) in this dryer is also remarkable and could be used for drying food products.

Open Access Original Research Article

Effect of an Active Open Dumpsite on the Earth’s Subsurface and Groundwater Resource

Alao J. Omeiza, O. O. Abdulwahab, M. S. Nur, T. T. Danjuma, Emmanuel Jaiyeoba, Diya’ulhaq Abdullahi, Oluseyi O. Adekanye, Ekwu T. Mary

Asian Journal of Physical and Chemical Sciences, Page 15-24
DOI: 10.9734/ajopacs/2022/v10i230152

An electrical resistivity survey was carried out at a dumpsite and controlled station located about 200m away from the dumpsite to assess the vertical extent of leachate contamination of the dumpsite and its impact on the soil and groundwater resources. Subsurface resistivity of the dumpsite and the controlled stations were examined, which reflects the subsurface soil tolerance and the impact of the vertical extent of leachate contamination on the subsurface. The leachate infiltration may reflect the state and the quality of the groundwater.  This implies that leachates from the dumpsite must have also migrated into the aquifer system, thereby contaminating the water-bearing unit.

Open Access Original Research Article

Assessment of Heavy Metal Concentration in Soil and Plant and Evaluation of Bioconcentration Factor at Loumbila Market Gardening Perimeters, Burkina Faso

Bambara Telado Luc, Kabore Karim, Derra Moumouni, Tougma Kiswendsida Alain, Ousmane Ibrahim Cisse, Francois Zougmore

Asian Journal of Physical and Chemical Sciences, Page 25-34
DOI: 10.9734/ajopacs/2022/v10i230153

Agricultural soil quality deterioration resulting from an increase in the level of heavy metals is becoming more and more pronounced, thus raising the question on the safety status of human health and the environment. Determination of heavy metal concentration in soils and plants from Loumbila market gardening (Burkina Faso), and calculation of bioconcentration factor were undertaken. The heavy metals such as copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), cadmium (Cd) and zinc (Zn) were measured using an atomic absorption spectrometer, model PERKIN ELMER AANALYST 200.

In the soil where the pepper was grown, the concentration of chromium was 175 mg/kg, which is higher than the concentration limit which is 150 mg/kg. Also the concentrations of lead in the soils of onion (118 mg/kg), green bean (118 mg/kg), carrot (178 mg/kg) and pepper (135 mg/kg) were above the limit which is 100 mg/kg. The concentrations of chromium in Onion leaves (3.72 mg/kg), onions (4.65 mg/kg), lettuce (4.89 mg/kg), green beans (5.89 mg/kg) and bell peppers (3.56 mg/kg) were concentrations above the limit established by the FAO/WHO, which is 2.3 mg/Kg. The concentrations of lead in carrot, onion leaf, onion, lettuce, green bean and bell pepper were above the limit proposed by FAO/WHO.

The bioconcentration factors show that the onion leaf (0.731), onion (0.929), lettuce (0.876), green bean (0.987) and bell pepper (0.858) are the plants that accumulate zinc and the carrot (0.524) accumulates nickel. The bioaccumulation of the metals in the vegetable from Loumbila market gardening decreased in the order of onion > lettuce > green bean > bell pepper > onion leaves > carrot.

Open Access Original Research Article

Variability of f_o E in Relation to the Solar Indices (R_z and F_(10.7) ) at the Equatorial Ionosphere (Ouagadougou Station)

Sawadogo Gédéon, Konaté Moustapha, Nakolemda Roger, Nanéma Emmanuel

Asian Journal of Physical and Chemical Sciences, Page 35-41
DOI: 10.9734/ajopacs/2022/v10i2179

The correlation coefficients between the critical frequency of the ionosphere E-layer ( foE )and the solar radio flux have not been formally evaluated at the Ouagadougou station. The purpose of this paper is to conduct a study on the variability of the critical frequency of ionosphere E-layer with the solar radio flux (F10.7) and sunspot number (Rz) at the Ouagadougou station. The Ouagadougou station is located at the equatorial ionosphere whose coordinates are: lat: 12.5°N; long: 358.5°E; dip 1.5. Moreover, the local time is equal to the universal time (LT=UT). We worked on the solar cycles 21 and 22 (SC21 and SC22) considering their different phases (minimum, increasing, maximum, and decreasing). The values of foE taken into account are those measured at noon (12:00 LT). The results show a good correlation between foE and Rz, and between foE and F10.7. Thus, the correlation coefficient evaluated between  foE and Rz is 0.96 at SC21 and 0.93 at SC22, and between foE and F10.7 is 0.95 at SC21 and 0.93 at SC22. We subsequently compared foE of the two solar cycles for the same phase. The calculated deviation between the minimum of SC21 and SC22 is 4.46%.  We then find a very small variation of foE from a solar cycle to another at the minimum phase, and this is also verified at the other phases.

Open Access Original Research Article

Improving Students’ Science Process Skills Using Argument-Driven-Inquiry (ADI) Laboratory Method

Joan M. Belga

Asian Journal of Physical and Chemical Sciences, Page 42-49
DOI: 10.9734/ajopacs/2022/v10i2180

This study aimed to determine the effects of the Argument-Driven-Inquiry (ADI) laboratory method on high school students’ science process skills. The study further investigated the method’s effect on students with different reasoning ability levels, namely the hypothetico-deductive, transitional, and empirical-inductive. A mixed method employing both quantitative and qualitative procedures for gathering data was employed. A quasi-experimental study using a 2 x 3 factorial design was implemented where Reasoning Ability Level was the moderating variable. The study was conducted on two intact classes of fourth-year students at Iloilo National High School-Special Science Class enrolled in the subject “College Physics”. Lawson’s Classroom Test of Scientific Reasoning was utilized to categorize students according to their reasoning ability levels.  To measure students’ science process skills before and after the study, the Test for Integrated Process Skills II (TIPS II) was employed. Mean, standard deviations, t-test for independent samples, and one-way analysis of variance were determined as part of the statistical analyses. Results revealed that students in the two groups were comparable in terms of science process skills before the intervention was employed. However, exposure to the ADI laboratory method improved students’ science process skills better than exposure to the traditional laboratory method. Further, the improvement of students’ science process skills is deemed independent of the student’s reasoning ability level but relies mainly on the type of laboratory instruction.