2.3 SOLAR CONCENTRATOR : Solar concentrator is a device which concentrates the solar energy incident over a large surface onto a smaller surface. The concentration is achieved by the use of suitable reflecting or refracting elements, which results in an increased flux density on the absorber surface as compared to that existing on the concentrator aperture. In order to get a maximum concentration, an arrangement for tracking the sun’s virtual motion is required. An accurate focusing device is also required. Thus, a solar concentrator consists of focusing device, a receiver system and a tracking arrangement .Temperature as high as 300C can be achieved using solar concentrators, and hence they have potential applications in both thermal
Electromagnetic waves Radiation from the Sun, which is more popularly known as sunlight, is a mixture of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV) Sun is not the only example of electromagnetic source, An electromagnetic wave can be created by accelerating charges; moving charges back and forth will produce oscillating electric and magnetic field and these travel at the speed of light. It would really be more accurate to call the speed "the speed of an electromagnetic wave", because light is just one example of an electromagnetic wave. Nothing can travel faster than light in a vacuum. It’s ultimate speed limit in the universe. speed of light in vacuum: c = 3.00 x 〖10〗^8 m/s A magnetic field is produce by a moving charges ,A constant current produces a constant magnetic field, while a changing current produces a changing field.
They are usually made of silicon or Germanium (Ambroziak, 2010). A resistor placed in series with the phototransistor controls the sensitivity of the phototransistor to light. A higher resistance makes the phototransistor circuit more sensitive to
3.1 Hear E is energy (in joules), h is Planck’s constant (6.62 × 10-34 Js), and ν is frequency (in seconds) . Thus in UV-visible spectroscopy, the low wave length UV light has the highest energy. Actually UV-Vis is a subclass of spectroscopy that uses visible light and adjacent near ultraviolet ranges for the determination of the concentration and the characterization of dissolved substance. Again the absorption of light is a physical process in which the amount of absorbed light depends on concentration of the substance C, the thickness of the liquid layer d and a specific absorption coefficient α at a given wavelength λ. The phenomenon of light transmission through a sample can be described by the fraction of light at a specific wavelength λ that passes through the sample (Fig 3.7).
Those kind of systems take the heat of the sunlight directly to the system. For example let’s take drying some cloths in sunlight. What happens there is the system is getting heat and increasing temperature. But when considering an active system requires some special technology to absorb and collect solar radiation and then store that heat energy. So according to that definition, Solar thermal power plants are active systems and we can see different types of solar thermal power plants.
Renewable energy is energy that is collected from renewable resources such as sunlight, water, wind, and geothermal heat. A common form of renewable energy is solar energy. Solar energy is radiant light and heat from the Sun that is harnessed by using technologies such as solar heating, photovoltaics, solar thermal energy, and more. The Sun releases pockets of energy called photons that travel from the Sun to the Earth in a matter of minutes. When photons hit a solar panel, they knock electrons lose from their atoms.
To measure the temperature of working fluids by that parabolic dish for different days and different times of the day. CHAPTER 2 2.1 Experimental setup: Solar parabolic dish consists of the following components 2.1.1. Parabolic dish: The concentrator focuses the direct normal irradiance (DNI) onto the receiver, where the heat is used in the energy conversion process. The key parameters in analyzing the operation of the concentrator are the dish aperture diameter d (m), mirror reflectivity , and irradiance I (W/m2). Parabolic dish is a point focus concentrator with shape of a circular parabolic (surface of revolution generated by a parabola around its axis).
This is because the vast amounts of energy that made freely available, if harnessed by modern technology. In the form of solar radiation, this solar energy can makes the production of solar electricity. From photovoltaic, PV, cells electricity can be produced directly. Photovoltaic means “light” and “electric”. These cells are made from materials which
It is also important to consider the thermal characteristics of the solar chimney and design the solar chimney with materials that absorb the most heat, which generally includes a black frame, tinted glass, and insulated glazing. Size of the solar chimney is another important consideration,
They have been made for the extreme UV sensitive cameras for instrumentation on ESA (European Space Agency) Solar Orbiter mission. 2) Active Pixel Sensors (APS) are being used for the detection of ionizing particles (photons, alpha, beta, or gamma particles). ACTIVE PIXEL SENSOR AS A RADIATION SENSOR A radiation sensor detects incoming ionized particles (such as photons, β, gamma or alpha particles) and gives information like the energy, the intensity or the position of the radiation , to the user. The main element of radiation detector is an Inverse biased Photodiode. When an incoming radiation with an energy near or greater than the silicon band gap crosses the depleted region of the p-n junction, some electrons jumps from the Valence bond to the Conduction band and electron hole pairs are created ; the produced electron hole pairs are parted by an electric field formed at the junction and are collected at the electrodes of the photodiode.