Assemble and Demonstrate of Solar Panel to Operate a small fan (Grade VIII, State Standard)

Overview: The World has great shortage of energy. The main sources of producing energy are oil, gas, coal etc. However, these sources are too much expensive and needs great efforts, resources to be utilized for industrial as well as domestic purposes. Sun is the main source of energy. it releases energy at a mass-The rate of conversion of energy is 4.26 million metric tons per second, which produce 3.846x10 26 W. In Pakistan shortage of energy is the main problem. Industries and household requirements are several times greater than energy production by Hydroelectric mechanism. Pakistan is seeking alternatives for production of energy. Solar Panels are one of the cheap sources of production of energy. Solar Photovaltaic was discovered back in 1839 by French scientist Edmond Becquerel. Over the course of the next 100 years, many discoveries and inventions were made and by 1954, Daryle Chapin, Gerald Pearson and Calvin Fuller were the first to design the first silicon photovoltaic cell which was the precursor of all silicon cells today. Over the next few decades, solar power technology continued to develop. Photovoltaic research and development discovered new material, cell designs and novel approaches to solar material and product development. Now a days, solar panels are available all over world for converting solar energy to electricity. In Pakistan, they are widely used in areas Where the hydroelectric power has not reached, or to cope with the effects of load shedding in urban areas. Today we are going to design assemble and demonstrate a model of a fan run by a solar panel. Objectives of the lesson:  To Develop curiosity in students about Scientific approach.  To shift the students from rote memorization towards inquiry-based learning.  To enable them to create ideas, think critically and logically and solve problems themselves.  To develop and inculcate the zeal of Science, Technology, Engineering and Mathematics.

The Effectiveness of Development Results of Pro-show Media Based on Solar System Poem and Song on Student Learning Outcomes

The purpose of this study was to determine the effectiveness of the results of the development of poem and song-based proshow media on MI Al-Falah Soropadan District of Pringsurat students' learning outcomes in the solar system material. The research method used is quantitative with One-Group Pretest-posttest design. The subjects of the study were sixth graders of MI AL-Falah Soropadan and teachers in Pringsurat District. The research instruments were pretest and posttest of solar material. T-test results obtained t -73.676, p = 0.00 0.05, which means that the poem and song-based proshow media development results are effective on MI Al-Falah Soropadan Pringsurat District students' learning outcomes in solar system material. Poem and song-based proshow media provide solutions for teachers and students in increasing mastery of science subjects.

Elements of Stars

What are stars made of? Less than 200 years ago this basic, simple question was deemed impossible to answer. As Auguste Comte put it in 1835: “On the subject of stars…While we can conceive of the possibility of determining their shapes, their sizes, and their motions, we shall never be able by any means to study their chemical composition or their mineralogical structure.” Today, we have a broad, clear answer to the question: “What are stars made of?” We also understand its far-reaching implications in relation to the evolution of the cosmos. Satellites and many ground-based spectroscopic surveys routinely provide new discoveries on the chemical composition of astronomical objects. In parallel, the nuclear processes that produce the elements inside stars are investigated in increasingly sophisticated nuclear physics experimental facilities across the world. At the same time, supercomputers allow us to calculate detailed models of the evolution of stars and galaxies: how much of which element is produced where? Finally, the presence of tiny amounts of extra-solar material can be found within meteorites, whose analysis is reaching unparalleled precisions with uncertainties down to parts per million. How have we managed to travel from an impossible question to such broad knowledge filled with discoveries?

EVALUACIÓN DE UNA TERMA SOLAR CONSTRUIDA CON SUPERFICIE ABSORBEDORA DE LATAS DE ALUMINIO

En este trabajo se diseñó y evaluó una terma solar, en la cual se usaron latas de aluminio de bebidas gaseosas para la superficie absorbedor del colector solar, material que por su alta conductividad térmica asegura buena absorción de la radiación solar incidente para calentar agua, con la finalidad de usarla en diferentes aplicaciones domésticas en la ciudad de Tacna. Para conseguir esto se pintaron las latas con pintura negro-mate de excelente absorbancia comprobada en anteriores experimentos realizados; y para transportar el líquido caloportador se usaron mangueras para riego tecnificado de segundo uso. Los resultados preliminares obtenidos nos indican que la eficiencia instantánea llega al 46 %, lo cual nos permite concluir que el comportamiento térmico de los materiales utilizados es comparable con el comportamiento de los materiales usados por los fabricantes de termas solares convencionales de placa plana. La ventaja de estos sistemas es el menor costo de producción y su contribución al reúso de materiales considerados como residuos sólidos.

Investigation of defects in crystalline silicon solar cells by confocal Raman spectroscopy

Defects in solar cells can be caused during processing or through a benign event like a falling leaf when operating in an outdoor system. Shading caused by such a leaf can result in the cell operating in the reverse direction and ultimately in hotspot formation, which in turn can cause the entire cell to breakdown and essentially become a power dissipator rather than a producer. More often than not, this reverse biasing of the cell will enhance the effect of any inherent defect. In this study, poly-Si cells were reverse biased to enhance the effect of their inherent defect. These defects were then analysed using non-destructive confocal Raman spectroscopy, since this technique allows us to observe small defects in cells/material using the intensity of the transverse optic bands. The intensity of defect-induced Raman band has a direct relationship with the observed morphological defects of the reverse biased cell. The quality of the active layer was also investigated; this includes the chemical composition and the stress level which can be found through the single spectrum bandwidth. The efficiency of solar material depends on the absorption capability of the solar material, while the optical and the electrical properties to a large extent determine the absorption capability of solar cell. However, its structure, defect and stress level can offset the total optical and electronic properties. The present study reveals defect in micro-level and the stress induced in the affected region of the solar cell. Confocal Raman is suitable for characterising stresses in relation to microstructure, defect level as well as the manufacturer-induced defect in the substrate.

A hybrid functional study of native point defects in Cu2SnS3: implications for reducing carrier recombination

Study of defect chemistry in the earth-abundant solar material Cu2SnS3 reveals abundant deep centers causing recombination under typical experimental conditions.