scholarly journals Solar radiation modelling and measurement techniques in Lafia Zone, Nasarawa state, Nigeria

2020 ◽  
Vol 7 (1) ◽  
pp. 48-55
Author(s):  
Andah Mamman ◽  
Umaru Ibrahim ◽  
Mustapha M. Idris ◽  
Abdullahi A. Mundi ◽  
Musa U. Sarki
Keyword(s):  
Solar Radiation ◽  
Transmission Coefficient ◽  
Prediction Models ◽  
Measurement Techniques ◽  
Sampling Technique ◽  
Global Solar Radiation ◽  
Mean Value ◽  
Atmospheric Transmission ◽  
Average Value ◽  
Solar Radiation Intensity

The number of solar radiations measuring stations in Nigeria has been observed not to effectively describe the necessary variability; as such prediction models are necessary for estimation of solar radiation values using readily available meteorological variables. In this study, solar radiation parameters were determined for Lafia zone, Nasarawa State, Nigeria. Twelve (12) location were carefully selected to avoid sunshine and wind obstruction using a systematic random sampling technique. Three-hour daily measurement (12.00 pm to 2.00 pm) was done on three 12V, 5W solar panels using a pyranometer and the output was estimated using the Angstrom-Prescott Regression Equation. The continuity in the assembled system was measured using an Avometer. The result revealed that solar radiation intensity was found to range from 165.5 W/m2 to 298.6W/m2 with the mean value of 241.24 W/m2.The highest global solar radiation value of 29.8MJ/m2was observed in April while the lowest value of 16.5MJ/m2was observed in August. The extraterrestrial solar radiation was found to range from 9.06 MJ/m2 in August to 26.60 MJ/m2 in February with average value of 20.96MJ/m2. The atmospheric transmission coefficient over the year is found to range from 0.7 in July and September to 1.4 in December. The obtained atmospheric transmission coefficient determined for the year (2019) is a good indication for solar radiation application in Lafia geo-political zone, Nasarawa State. The performance of the developed model is observed to imply that it can be used to predict global solar radiation for Lafia zone in Nasarawa State.

scholarly journals Variation of Solar Radiation in Akwanga, Nasarawa State, Nigeria

2020 ◽  
pp. 17-24
Author(s):  
Andah Mamman ◽  
Umaru Ibrahim ◽  
Yusuf Samson Dauda ◽  
Idris Mohammed Mustapha ◽  
Bartholomew Paul
Keyword(s):  
Solar Radiation ◽  
Transmission Coefficient ◽  
Global Solar Radiation ◽  
Mean Value ◽  
Solar Panels ◽  
Atmospheric Transmission ◽  
Measurement Interval ◽  
Average Value ◽  
Solar Radiation Intensity ◽  
Earth’S Climate

One of the major environmental problem is the long-term changes in the Earth’s climate. In this study, the variation of solar radiation for Akwanga zone, Nasarawa State, Nigeria were determined. Twelve locations were carefully selected where there is no sunshine and wind obstruction. Three 12V, 5W Solar panels (poly) were used and a three-hour daily measurement interval (12.00 pm to 3.00 pm) was made using the Secondary Standard Pyranometer placed on the top of the panels. Angstrom-Prescott Regression Equation was used to estimate the output. The continuity in the assembled system was measured using an Avometer. The result revealed that the highest monthly average daily global solar radiation was observed in the month of April (25.2 MJ/m2) followed by June (22.94 MJ/m2), and march (22.42 MJ/m2), while the lowest was observed in the month of August (12.04 MJ/m2) followed by July (13.57 MJ/m2), and September (14.26 MJ/m2) in the locations selected. The solar radiation intensity was found to range from 156.44 W/m2 to 293.84 W/m2 with the mean value of 220.04 W/m2. The highest total global solar radiation value of 25.2MJ/m2 was observed in April while the lowest value of 12.04 MJ/m2 was observed in October. The extraterrestrial solar radiation were found to range from 16.72 MJ/m2 in March to 29.90 MJ/m2 in April with average value of 22.89MJ/m2. The atmospheric transmission coefficient over the year is found to range from 0.5 in July and October to 1.3 in June and October. The investigation reveal that there is bright sun shine in the study area which confirms high atmospheric transmission coefficient or clearness index throughout the year in this study.

scholarly journals Compatibility of different measurement techniques. Long-term global solar radiation observations at Izaña Observatory

2016 ◽  
Author(s):  
Rosa Delia García ◽  
Emilio Cuevas ◽  
Omaira Elena García ◽  
Ramon Ramón ◽  
Pedro Miguel Romero-Campos ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Sunshine Duration ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Multifilter Rotating Shadowband Radiometer ◽  
High Consistency

Abstract. A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain) starting on July 17, 2014. We compare global solar radiation (GSR) records measured with a CM-21 pyranometer Kipp & Zonen, taken in the framework of the Baseline Surface Radiation Network, with those measured with a Multifilter Rotating Shadowband Radiometer (MFRSR), and a bimetallic pyranometer (PYR), and GSR estimated from sunshine duration performed by a Campbell-Stokes sunshine recorder (CS) and a Kipp & Zonen sunshine duration sensor (CSD). Given the GSR BSRN records are subject of strict quality controls (based on principles of physical limits and comparison with the LibRadtran model), they have been used as reference in the intercomparison study. We obtain an overall root mean square error (RMSE) of ~0.9 MJm2 (4 %) for GSR PYR and GSR MFRSR, 1.9 MJm2 (7 %) and 1.2 MJm2 (5 %) for GSR CS and GSR CSD, respectively. Factors such as temperature, fraction of the clear sky, relative humidity and the solar zenith angle have shown to moderately affect the GSR observations. As application of the methodology developed in this work, we have re-evaluated the GSR time series between 1977 and 1991 obtained with two PYRs at IZO. By comparing with coincident GSR estimates from SD observations, we probe the high consistency of those measurements and their temporal stability. These results demonstrate that 1) the continuous-basis intercomparison of different GSR techniques offers important diagnostics for identifying inconsistencies between GSR data records, and 2) the GSR measurements performed with classical and more simple instruments are consistent with more modern techniques and, thus, valid to recover GSR time series and complete worldwide distributed GSR data. The intercomparison and quality assessment of these different techniques have allowed to obtain a complete and consistent long-term global solar radiation series (1977–2015) at Izaña.

scholarly journals Pengaruh Model Pembelajaran Problem Based Learning pada Materi Hukum-Hukum Dasar Kimia terhadap Hasil Belajar Siswa Kelas X MAN 2 Model Palu

2018 ◽  
Vol 7 (3) ◽  
pp. 102
Author(s):  
Tri Sulistiyawati Lamalat ◽  
Supriadi Supriadi ◽  
Siti Nuryanti
Keyword(s):  
Statistical Analysis ◽  
Learning Outcomes ◽  
Problem Based Learning ◽  
Sampling Technique ◽  
Learning Model ◽  
Mean Value ◽  
Control Group ◽  
Control Group Design ◽  
Average Value ◽  
Quasi Experimental

Research on the effect of the problem-based learning model in the basic laws of chemistry on student’s learning outcomes in class X MAN 2 Model Palu has been done. This study aimed to determine the effect of the application of the problem-based learning model in the basic laws of chemistry on student’s learning outcomes in class X MAN 2 Model Palu. The type of research was a quasi-experimental study non-randomized design with pretest-posttest control group design. The sample was conducted with a purposive sampling technique. The study sample was students in class X MIA 6 as an experimental group (n = 22) and students in class X MIA 3 as a control group (n = 22). The data testing of students' learning outcomes used a non-parametric statistical analysis, the analysis of Mann-Whitney U-Test. The research results indicated that the mean value of the experiment class was high compared to the control class, 22.61 >18.39. The statistical analysis obtained that sig. 2-tailed (0,032) ˂ 0.05 and Zcalculation (-2.149) ˂ Ztable (-1.96). The average value of the experiment class was 82.95 while the average value of the control class was 73.64. So it can be concluded that there is the effect of applying the problem-based learning model in the basic laws of chemistry on student’s learning outcomes. 

scholarly journals Developing mathematical models for global solar radiation intensity estimation at Shakardara, Kabul

2021 ◽  
Vol 4 (2) ◽  
pp. 133-138
Author(s):  
Abdul Basit Da’ie
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Mathematical Models ◽  
Radiation Intensity ◽  
Global Solar Radiation ◽  
Suitable Model ◽  
Intensity Estimation ◽  
Solar Radiation Intensity ◽  
Sunshine Hours ◽  
Atmospheric Data

Solar energy properties such as Global Solar Radiation (GSR) intensity could be determined in either methods, experimentally or theoretically. Unfortunately, in most countries including Afghanistan, the first method which is more acceptable, but due to the high cost, maintenance and calibration requirements is not available. Therefore, an alternative widely used way is the second one which is model developments based on the meteorological (atmospheric) data; specially the sunny hours. The aim of this study at Shakardara area is to estimate atmospheric transparency percentage on 2017, determining the angstrom model coefficients and to introduce a suitable model for global solar radiation prediction. The hourly observed solar radiation intensity H (WHm-2 ) and sunshine hours S (

scholarly journals Global Solar Radiation Prediction Using Hybrid Online Sequential Extreme Learning Machine Model

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3415 ◽  
Author(s):  
Muzhou Hou ◽  
Tianle Zhang ◽  
Futian Weng ◽  
Mumtaz Ali ◽  
Nadhir Al-Ansari ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Extreme Learning Machine ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Renewable Energy Sources ◽  
Information Criterion ◽  
Absolute Error ◽  
Global Solar Radiation ◽  
Machine Model ◽  
Learning Machine

Accurate global solar radiation prediction is highly essential for related research on renewable energy sources. The cost implication and measurement expertise of global solar radiation emphasize that intelligence prediction models need to be applied. On the basis of long-term measured daily solar radiation data, this study uses a novel regularized online sequential extreme learning machine, integrated with variable forgetting factor (FOS-ELM), to predict global solar radiation at Bur Dedougou, in the Burkina Faso region. Bayesian Information Criterion (BIC) is applied to build the seven input combinations based on speed (Wspeed), maximum and minimum temperature (Tmax and Tmin), maximum and minimum humidity (Hmax and Hmin), evaporation (Eo) and vapor pressure deficiency (VPD). For the difference input parameters magnitudes, seven models were developed and evaluated for the optimal input combination. Various statistical indicators were computed for the prediction accuracy examination. The experimental results of the applied FOS-ELM model demonstrated a reliable prediction accuracy against the classical extreme learning machine (ELM) model for daily global solar radiation simulation. In fact, compared to classical ELM, the FOS-ELM model reported an enhancement in the root mean square error (RMSE) and mean absolute error (MAE) by (68.8–79.8%). In summary, the results clearly confirm the effectiveness of the FOS-ELM model, owing to the fixed internal tuning parameters.

scholarly journals Study of Linke Turbidity Factor on Solar Radiation over Jumla

2019 ◽  
Vol 9 ◽  
pp. 141-149
Author(s):  
Prakash M. Shrestha ◽  
Indra B. Karki ◽  
Narayan P. Chapagain ◽  
Khem N. Poudyal
Keyword(s):  
Air Pollution ◽  
Solar Radiation ◽  
Global Solar Radiation ◽  
Spectral Measurements ◽  
Annual Average ◽  
Average Value ◽  
Strong Relation ◽  
Rain Fall ◽  
Linke Turbidity Factor ◽  
Temperature Water

 Population growth, mechanization, and industrialization are the by product of human civilization and its resultant impacts goes to degrade the natural environment by the affecting of air-pollution and also associated with climatic change. Linke turbidity factor (LT) is an important parameter for assessing the air pollution at Jumla (Lat.:29.28o N, Long.: 82.16o E and Alt. 2300 masl). Because of the unavailability of spectral measurements data , a model has been used to estimate the Linke turbidity factor (TL) from broadband measurement of Global Solar radiation in 2012 .The annual average solar insolation, clearness index (KT) and extinction coefficient (K) are 5.11 ±2.34kWh/m2/day ,0.71 ± 0.12 and 0.25 ± 0.13 respectively. Similarly, the annual average value of Linke turbidity factor (LT) and visibility 1.97± 0.47 and 28.09 ± 21.08 km are found. Finally it is found that there is strong relation between Linke turbidity factor and meteorological parameters i.e. relative humidity, temperature, water content, ozone and rain fall.

scholarly journals PENGARUH LATIHAN AEROBIK TERHADAP FORCED VITAL CAPACITY (FVC)PRIA DEWASA DENGANOVERWEIGHT

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Ester Florencia Sagay ◽  
Hedison Polii ◽  
Herlina I. S. Wungouw
Keyword(s):  
Aerobic Exercise ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Sampling Technique ◽  
Mean Value ◽  
Average Value ◽  
Significant Difference ◽  
Before And After ◽  
Post Test ◽  
The Mean

Abstract: Changes to respiratory function due to regular aerobic exercise will affect the value of pulmonary function, especially in Forced Vital Capacity (FVC). This research aimed to determine the effect of aerobic exercise on FVC overweight male students of Unsrat Medical Faculty. This research is analytic with design experimental, one group pre and post test design. The sampling technique used is non-purposive sampling technique. The research sample was taken from the students of the Faculty of Medicine 2009, Univercity of Sam Ratulangi who fulfill the inclusion criteria. Some 32 students were selected as research subjects. After giving informed consent, FVC measurement was done with the spirometer. After it was measured, they were given treatmen in the form aerobic exercise using a stationary bike for three weeks with frequency of exercise three times a week and exercise intensity for 30 minutes. We measured again FVC values after the exercise three times program. Normality test data showed significance for FVC value before treatment by 0.752, and after treatment by 0.912. Comparison of the average value before and after exercise were tested by using a paired test. Significant value for FVC is P = 0.084, means there is no significant difference between FVC values before and after exercise (P> 0.05). The mean FVC was 3.88 before treatment and after treatment the mean value was 4.00, an increase in the average value of 0.11. Conclusion:Aerobic Exercise on a regular basis using a stationary bike on the overweight male student can improve lung function in particular the mean FVC but there was no significant difference from the mean value. Keywords: FVC, Aerobic Exercise, Overweight.   Abstrak: Perubahan fungsi pernapasan karena latihan aerobik secara teratur akan mempengaruhi nilai fungsi paru khususnya Forced Vital Capacity (FVC). Penelitian ini untuk mengetahui pengaruh latihan aerobik terhadap FVC mahasiswa pria Fakultas Kedokteran Unsrat dengan berat badan lebih.Penelitian ini bersifat analitik dengan rancangan eksperimental one grup pre and post test design. Pengambilan sampel dilakukan dengan teknik non purposive sampling. Sampel penelitian diambil dari Mahasiswa Fakultas Kedokteran Universitas Sam Ratulangi Angkatan 2009.Sejumlah 32 orang mahasiswa terpilih sebagai subjek penelitian dan dilakukan pengukuran FVC dengan Spirometer.Setelah itu diberikan perlakuan berupa latihan aerobik menggunakan sepeda statis selama tiga minggu dengan frekuensi latihan tiga kali seminggu dan intensitas latihan selama 30 menit.Selanjutnya dilakukan pengukuran kembali nilai FVC sesudah program latihan.Uji normalitas data menunjukkan nilai signifikansi untuk FVC sebelum perlakuan sebesar 0.752, dan sesudah perlakuan sebesar 0.912. Perbandingan nilai rata  rata  sebelum dan sesudah latihan diuji dengan menggunakan uji t berpasangan.Nilai signifikan untuk FVC adalah P = 0.084, berarti tidak terdapat perbedaan yang bermakna antara nilai FVC sebelum dan sesudah latihan (P > 0.05) .Nilai rerata FVC sebelum pelakuan adalah 3,88  dan nilai rerata sesudah perlakuan adalah  4,00,  terjadi penigkatan nilai rerata sebesar 0,11.Simpulan:Latihan Aerobik menggunakan sepeda statis secara teratur dapat meningkatkan nilai rerata fungsi paru khususnya FVC tetapi tidak terdapat perbedaan yang bermakna dari nilai rerata tersebut. Kata Kunci: FVC, Latihan Aerobik, Berat Badan Lebih (Overweight).

Simulation of Solar Radiation Heat Flux Data for Energy Calculation

1996 ◽  
Vol 118 (1) ◽  
pp. 58-63 ◽  
Author(s):  
A. Panek ◽  
Y. Lee ◽  
H. Tanaka
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Solar Irradiation ◽  
Easy Access ◽  
Energy Calculation ◽  
Radiation Heat ◽  
Statistical Parameters ◽  
Solar Radiation Intensity ◽  
Autocorrelation Time ◽  
Level Of Agreement

The global (or total) and diffuse solar irradiation data are not always available in many areas of the world and they have to be estimated using some sort of empirical models. This paper describes how the sequence of hourly irradiation data can be simulated using some statistical parameters of the global solar radiation intensity such as the monthly average and variance of its daily maxima and autocorrelation time constant. The results of this simulation are compared with the measured data for two different locations, Ottawa, Canada and Warsaw, Poland (these two locations are chosen because of easy access to the radiation data). The comparison shows an acceptable level of agreement between the simulated and measured results.

On the prediction of the daily global solar radiation intensity on south-facing plane surfaces inclined at varying angles

2016 ◽  
Vol 120 ◽  
pp. 397-411 ◽  
Author(s):  
Y. El Mghouchi ◽  
E. Chham ◽  
M.S. Krikiz ◽  
T. Ajzoul ◽  
A. El Bouardi
Keyword(s):  
Solar Radiation ◽  
Radiation Intensity ◽  
Global Solar Radiation ◽  
Solar Radiation Intensity
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