We are facing lots of screens and displays today starting with computer monitors, TVs and smart phones and ending with more sophisticated virtual reality (VR) displays like Oculus Rift. Most of them already use high resolution displays. For instance, Ultra HD 4k displays are becoming more and more available. But what does this mean and is this enough or too much? There are many tests and debates running about proper screen resolution when you have good picture quality and not wasting money for numbers only. This is not what are we are going to discuss. Everyone has to find their own optimal solution. Why not to do this rationally instead of chasing numbers.
Fig. 1 Screen door effect
From practical side, resolution alone doesn’t have significant meaning when choosing screen. You could take other two parameters in account – distance from screen and screen size. All those parameters goes along with human visual acuity – the smallest thing he can spot. When you go to the eye inspection you are given character chart where you need to point the smallest symbols you can see. The number next to that line represent your visual acuity. Continue reading
One of the pressing concerns of our age is environmental crisis. With the progressing technological evolution, the need for energy conservation and harvesting has increased. Harvesting energy is not an easy task, and most of the time, generating energy creates pollution in the environment. To deal with it, the international community has changed its approach so that it is now focused on identifying the areas where energy is being wasted and rectifying those issues instead of producing more energy.
The low power factor is one of those aforementioned issues. Power factor is a measure of lag in current with respect to voltage. Its value varies from zero to one. This lag creates a component of electrical power that is not being used and keeps oscillating between generation and consumer ends. This circulation of power dissipates energy in the form of heat and also creates extra load on the generation end. A power factor issue arises due to the presence of inductive loads, such as electric motors, fans, etc. Now the power companies have started to penalize industries that have high inductive loads and a very low power factor.
The industries are taking initiatives to increase their power factor. There are two methods of a power factor correction. One is using active circuit elements, such as a buck converter or a boost converter. This method is very expensive and has a large payback period. The other method is passive power factor correction using capacitors. In this method, pre-calculated value capacitor banks are connected to the inductive system. The capacitors nullify the effect of an inductive load and bring the power factor closer to one. In case of industries, this reduces the wasted power dramatically and the energy strain on generation end decreases.
Due to long distance transmission of electrical power and with the presence of several transformers in between, the shape of a pure sine wave gets distorted by high frequency noise components. Nearly all of the electrical appliances are designed to operate specifically with pure sine wave voltage. These noise components reduce the efficiency of appliances and waste a component of power. Capacitors are used to absorb these high frequency components partially and improve the efficiency of the overall system.
An interesting development in the field of power engineering is the creation of supercapacitors. Supercapacitors can be considered to be a hybrid of electrochemical cells and capacitors. These capacitors have very high value of capacitance (around 3000 Farads) and have very high energy densities. These capacitors cannot be used for conventional capacitor applications. They can provide very large values of currents for a small amount of time. This is the property of supercapacitors that has been exploited by engineers in the field of automobile engineering and generation of electricity by non-conventional means. Continue reading
Thermoelectric devices are seen very often in various appliances. Small refrigerators, semiconductor chip coolers, medical chillers. Thermoelectric effect works in both directions – it can generate temperature difference when current flows or it can generate current when temperature difference is applied.
About thermoelectric effect
It is known for more than 100 years. There are several scientists who discovered this effect in one or another way. Probably you’ve heard Peltier effect. Jean Charles Athanase Peltier discovered that if you apply electrical current to junction of two materials it gets cold or hot (depending on current direction). Continue reading
A Fractal receiver is a receiver that can be damaged up into lesser parts. Fractal just means a part of, so in this scenario they are referring to a receiver that can have feelers added or aloof. By liability the Fractal receiver is next a notion called the self-similarity expect module. This typically means that you can detach or add in peer parts. If you ever took a lobby in Fractal Geometry, you’d learn the mathematical reasoning behind this. The mathematics behind this stunt is governed by the Mandelbrot Set.
Benoit Mandelbrot is the father of fresh day Fractal Geometry. These antennas activate by elate out rare electromagnetic signals that face a certain zone or size depending on how many Fractals the receiver itself has. Fractal Antennas aren’t outsized or awkward by any way. In detail they are very small and have legal world application in cellular phones or microwave ovens and other small electronic method. This receiver is rare in that it can activate at countless different frequencies at the same time. Continue reading
Probably no one is surprised with gasoline prices going up. By paying same amount of money you get less and less mileage everyday. Eventually you reach a point when you start thinking of some radical changes. Changing petroleum fuel in to another form of energy like electricity is a great choice, but radical move is impossible without radical infrastructure changes. If you choose an electricity driven vehicle you will face charging problem. Charging stations aren’t wide spread enough. And battery technology is till in progress to reach high energy density for acceptable price. We believe that future is for electric cars, but now we need some sort of middle point where we still could use what’s around us and be one step to future. Companies like Lexus (www.lexus.co.uk) has been intensively working on hybrid car technologies over a decade. They have reached really good results on efficiency, decreasing emissions and comfort of driving.
Hybrid cars usually have two types of motors – internal combustion and electric. Both in combination they increase fuel efficiency, lower CO2 emission. Some technical data can be found at http://www.lexus.co.uk/hybrid/index.tmex. Generally speaking there are two types of hybrid cars – Full Hybrid and Mild Hybrid. Continue reading