-Energy is considered a prime agent in the generation of wealth and a significant factor in economic development. Limited fossil resources and environmental problems associated with them have emphasized the need for new sustainable energy supply options that use renewable energies. Among available technologies for energy production from solar source, photovoltaic system could give a significant contribution to develop a more sustainable energy system. Solar Panel has its wide use starting from a simple 5W diode lamp to a few kW ac drives. A solar panel with a battery and a charge controller and other auxiliary devices like dc to ac converters constitute a Solar Home System (SHS).Solar home system (SHS) is becoming popular day by day and even poor households are now becoming interested to purchase solar home system due to its various advantages. Solar home systems (SHS) have a major problem that is low efficiency. It also decreases output day by day because of improper maintenances, effect of dust and shadow. Accumulation of dust on solar panel of solar photovoltaic (PV) system is a natural process. It was found from the study that the accumulated dust on the surface of photovoltaic solar panel can reduce the system"s efficiency by up to 35% in one month .In this paper we show that the effect of dust accumulation on the solar panel naturally and how it is possible to overcome this problem.

No abstract

An RFID (Radio Frequency Identification) based security and access control system is proposed in this paper. Recently, a crime against children is increasing in higher rate and it is high time to offer a safety system for the school going children. In this work, our aim is to build a security system to keep the student secure. This system provides a unique identification number that is RFID card. Generally, the RFID card will be scanned in an RFID reader. RFID reader will send data to Arduino where the database program is previously set. Arduino programs are written in C language. If anyone remains absent after school starts, the GSM module will send an automated SMS to his or her parents. Students may need to leave school for an emergency case. Then he/she can take special permission from the administration. There is a button set for the administration to open the gate immediately for this reason. Parents will be provided RFID card from the school authority. Because student card won't work for the second time in a day. So parents will have to scan their card after school to receive their children. And their card will only work after school. Hence, the risks of any occurrence are reduced and ensured the safety of the student.

No abstract

No abstract