Natural and artificial light sources. Artificial light sources and their effectiveness. Requirements for the use of artificial light sources
The very first source of light used by people in their activities was the fire of a fire. Over time, people have discovered that more light can be obtained by burning resinous woods, natural resins, oils and waxes. From point of view chemical properties such materials contain a higher percentage of carbon and, when burned, the carbon particles become very hot in the flame and emit light. Candle ancient time Lucina
As we have seen, light is the main tool of photography, so we must understand what types of light are there and control the lighting on the subject being photographed. Contrast arises from the difference in the reflection of light in the same subject. Areas with light differences, i.e. parts with a lot of light reflection - or very light - and parts with little reflection - or too dark, will result in very contrasty photographs. So pay close attention to how the object reflects the light. Polished and bright objects create reflections that can degrade the quality of the photo.
Gas lanterns Lighting gas obtained from the fat of marine animals (whales, dolphins) was used as fuel, later benzene was used. The idea to use gas for street lighting belonged to the future King George IV, and at that time still the Prince of Wales. The first gas lantern was lit at his residence, Carlton House. Two years later - in 1807 - gas lamps appeared on Pall Mall, which became the first street in the world with gas lighting. At that time, ignited gas was coming out of the open end of the gas pipe. Soon, to protect the burner, a metal lampshade with several holes was built. By 1819, 288 miles of gas pipes had been laid in London, supplying 51,000 lanterns with gas. Over the next ten years, most of the central streets of the largest English cities were already lit by gas.
You will train your gaze on the subtleties of enlightenment. Take a walk around the city, watching the illumination of the sun, the street and the surrounding area. Types of natural light depending on the time. Colors take on a "warm" tone. The contrast is great, watch the scenes with the front sun, that is, "against the light."
Sunlight has an angle of 45 degrees, which provides optimal illumination. Perfect time for group photos. Avoid! the contrast is too high, the shadows are dead and blinded by high lights. Low light dramatizes the scenes, setting the ideal volumes for photographs of nature and urban architecture. Night: There are several types of urban lighting. Don't forget to watch the moon, which works like a big hitter of sunlight!
Further progress in the field of invention and design of light sources was largely associated with the discovery of electricity and the invention of current sources. When heated by electric current, various conductive materials with a high melting point emit visible light and can serve as light sources of varying intensity. Such materials were proposed: graphite (carbon filament), platinum, tungsten, molybdenum, rhenium and their alloys. Electric incandescent lamps Electric incandescent lamps
The sun is the main source of natural light, while lamps are artificial light sources. Light is an electromagnetic wave which, in the case of natural light, has the sun as its source, and in the case of artificial light, energy generated from alternative sources.
No matter where the light comes from, it has a big impact on life on Earth. Natural light is self-generated and divided into a spectrum of colors, the visible colors of the rays that we feel. The spectrum contains light with shorter wavelengths and closer to violet at one end, and light with longer wavelengths and closer to red at the other. Accordingly, these rays are called ultraviolet and infrared and are not visible to the human eye. The full spectrum of light from natural sources is ideal for animal and plant life on Earth.
In the years Lodygin creates his first incandescent lamp. In the autumn of 1873, Lodygin's light bulbs light up on one of the streets of St. Petersburg. A contemporary of the inventor later wrote about this significant event: “A mass of people admired this lighting, this fire from the sky ... Lodygin was the first to take an incandescent lamp out of the physics office to the street” and consider the year the electric incandescent lamp was created. The first light bulbs of Lodygin were simply arranged. They look like modern light bulbs. The outer shell was a glass ball, into which two copper rods connected to a current source were inserted (through a metal frame). Between the rods, a coal rod or a coal triangle was strengthened. When an electric current was passed through such a conductor, coal, due to its high resistance, warmed up and glowed. At first, A.N. Lodygin did not pump air out of his lamps. He placed a fairly thick carbon rod in the glass bulb of the lamp and tightly, hermetically sealed the bulb. At the same time, as the inventor believed, all the oxygen of the air remaining inside the cylinder would quickly be used up for the oxidation of coal (i.e., for its combustion), and then, when there was no oxygen left in the lamp, the carbon rod would already serve properly without burning out and without breaking down. However, tests have shown that such lamps are still short-lived. They burned for about 30 minutes. Therefore, later the air from the lamps began to be pumped out. Candle Yablochkov Consists of 2 carbon rods, between which an arc discharge occurs. Lamp Lodygin
It is this type that allows plants and animals to develop. Darkness, a factor inherent in photoactivity in organisms, helps to rejuvenate and restore life forms at the cellular level. On the other hand, excessive exposure to sunlight has a harmful effect on a living organism. Harmful ultraviolet rays can lead to diseases such as skin cancer and cataracts, as well as damage the texture of the skin. For plants, light and dark periods are necessary for photosynthesis as they help balance cellular activity in terms of growth or repair.
Yablochkov's candles appeared on sale and began to diverge in huge quantities, each candle cost about 20 kopecks and burned for 1½ hours; after this time, a new candle had to be inserted into the lantern. Subsequently, lanterns with automatic replacement of candles were invented. kopecks In February 1877, the fashionable shops of the Louvre were illuminated with electric light. Then Yablochkov's candles flared up on the square in front of the opera house. Finally, in May 1877, they illuminated for the first time one of the most beautiful thoroughfares of the capital, Avenue de lOpera. Inhabitants French capital, accustomed to the dim gas lighting of streets and squares, at the beginning of twilight, crowds flocked to admire the garlands of matte white balls mounted on high metal poles. And when all the lanterns flashed at once with a bright and pleasant light, the audience was delighted. No less admirable was the lighting of the huge Parisian covered hippodrome. Its running track was illuminated by 20 arc lamps with reflectors, and the seats for spectators by 120 Yablochkov electric candles, located in two rows of the Louvre Hippodrome.
Sunlight is also dangerous in the sense that it cannot be changed or controlled to suit human needs. Artificial light is generated by unnatural energy sources. Most human activity would be virtually impossible if there were no alternative light sources. The advantage of this light is that it can be controlled according to the needs and needs of the individual. In certain situations, you can properly control the intensity, quality and quantity of light.
A tungsten coil placed in a flask, from which air is pumped out, is heated by an electric current. Over the more than 120-year history of incandescent lamps, a huge variety of them have been created from miniature lamps for a flashlight to half-kilowatt projector lamps. The luminous efficacy Lm/W typical for LN looks very unconvincing against the record achievements of other types of lamps. LN are heaters to a greater extent than illuminators: the lion's share of the electricity supplying the filament turns not into light, but into heat. LN service life, as a rule, does not exceed 1000 hours, which, by time standards, is very little. What makes people buy (15 billion a year!) Such inefficient and short-lived light sources? In addition to the force of habit and the extremely low initial price, the reason for this is that there is a huge selection of different types of LN glass flasks. Modern incandescent lamps
Artificial light does not have a spectrum of colors or wavelengths as diverse as natural light, making it less useful. Because it is an inferior light, its effects on plants and animals are generally more harmful. Plants and animals exposed to long periods of time in artificial light suffer from degeneration or cell death much more frequently and intensely than living things exposed to natural light alone.
Natural light consists of electromagnetic energy generated by a natural source and contains a spectrum of colors and wavelengths suitable for terrestrial life. Artificial light uses artificial energy sources and creates light that is less versatile and more damaging to plants and animals if exposed for long periods of time. Moderate exposure to natural light is ideal for terrestrial life, but the same does not apply to artificial light, which is designed to illuminate indoors or at night.
An electric current passing through a tungsten coil) heats it up to high temperature. When heated, tungsten begins to glow. However, due to the high operating temperature, the tungsten atoms are constantly evaporating from the surface of the tungsten filament and depositing (condensing) on the less hot surfaces of the glass bulb, limiting the life of the lamp. In a halogen lamp, the iodine surrounding the tungsten enters into a chemical combination with the evaporated tungsten atoms, preventing the latter from deposition on the bulb. The tungsten atoms are thus concentrated either on the helix itself or near it. As a result, the tungsten atoms return to the spiral, which makes it possible to increase the working temperature of the spiral (to obtain brighter light), extend the lamp life. IRC halogen lamps (IRC stands for infrared coating). A special coating is applied to the bulbs of such lamps, which transmits visible light, but delays infrared (thermal) radiation and reflects it back to the spiral. Due to this, heat loss is reduced and, as a result, the efficiency of the lamp is increased. With infrared heat, energy consumption is reduced by 45% and the lifetime is doubled (compared to a conventional halogen lamp)
Interview with Giuliana Garrocho
Badly lit places evoke feelings of angst and sadness, while bright and well-lit environments create feelings of joy and pleasure. Natural light is considered an important contributing factor not only good health but also a sense of well-being and comfort for a person. Natural light has huge benefits and can be used as a strategy to achieve higher quality. environment and energy efficiency in buildings. Here's what Brasilia-based architect and urbanist Juliana Garrocho, author of Luz-luz and Architectural Design: Strategies for Anti-aircraft Lighting in Shopping Centers, thinks.
GAS-DISCHARGE LIGHT SOURCES OR COLD LIGHT LAMPS The operation of such lamps is based on the fact that gases, mostly inert, and vapors of various metals emit light when an electric current passes through them. This method of emitting light is called electroluminescence. In this case, each gas or vapor glows with its own color. Therefore, along with lighting, they are used for advertising and signaling.
She goes on to say that planning for the use of natural light in a project involves the involvement of several specialists. Giuliana Garrocho - Natural light is one of the most important sources of energy for a person who carries out his activities, as it provides a clear vision of the world. In addition, every living being depends on the effects of natural light to activate the cycle of physiological functions. However, in order to provide natural lighting that provides effective lighting for any task while providing a pleasant visual environment, it becomes necessary to know its advantages and disadvantages.
Fluorescent lamps(LL) discharge lamps low pressure They are a cylindrical tube with electrodes, into which mercury vapor is pumped. Under the action of an electrical discharge, mercury vapor emits ultraviolet rays, which, in turn, cause the phosphor deposited on the walls of the tube to emit visible light. LLs provide soft, uniform light, but it is difficult to control the distribution of light in space due to the large radiation surface. One of the main advantages of LLs is durability (service life up to hours). Due to their cost-effectiveness and durability, LLs have become the most common light sources in corporate offices. In countries with a mild climate, LLs are widely used in outdoor lighting of cities. In cold regions, their propagation is hindered by the fall of the light flux at low temperatures. If you "twist" the LL tube into a spiral, we get a CFL compact fluorescent lamp. Fluorescent lamps are energy saving Fluorescent lamps
Among the positive aspects of natural light, it can be said that the quality of the illumination received is better, since human vision has evolved with natural light, and the constant change in the amount of natural light in time and space is beneficial because it provides stimulant effects in the environment. However, it is also necessary to be aware of its disadvantages, such as direction and very high intensity, because the biggest disadvantage of natural light is its unpredictability.
Is it just because of the power saving problem? Natural light has always played an important role in architecture from an aesthetic and symbolic point of view, as well as in terms of comfort and functional lighting. Natural lighting can provide singular effects in a given space, giving it its own personality, creating scenographic aspects and striking the respective characteristics. With the advent of the international style, a projection method developed that was increasingly unrelated to the climatic features of the site and the comfortable needs of a person.
THE MAIN DEFECT OF THE NEW GENERATION LAMPS IS that they contain mercury vapor, approximately 3-5 mg of a substance each. Mercury belongs to the first hazard class (extremely dangerous chemical substance). The system for recycling energy-saving lamps in our country has not been thought out. There are practically no enterprises in the country that could properly dispose of these products. People are accustomed to throwing away used lamps along with ordinary household waste. AT this case it is unacceptable. Most great harm can bring organic mercury compounds formed after being hit chemical into the environment along with precipitation. Careless handling of energy-saving lamps can lead to mercury poisoning. For example, if you accidentally break just one light bulb, the excess of the maximum permissible concentration of mercury in the air will reach 160 times. As a result, a person is affected nervous system, liver, kidneys and gastrointestinal tract. If you accidentally break the bulb of an energy-saving lamp, ventilate the room immediately and thoroughly. In addition, new generation light bulbs produce more intense radiation than conventional ones. According to the British Association of Dermatologists, this can primarily affect people with increased skin sensitivity to photosensitivity. According to scientists, the use of energy-saving lamps can harm a person with skin diseases and lead to skin cancer, as well as cause migraines and dizziness in people with epilepsy.
The appearance of "glass curtains" has created a real icon of office buildings. The corresponding "greenhouse building" was thus exported as a symbol of strength without being adapted to the cultural and climatic characteristics of the destination. It can be said that during this period, increased attention was paid to the benefits of natural light. One of the characteristics of modern architecture is the use of large glazed facades, regardless of local climatic conditions. This indiscriminate use often causes buildings to overheat due to excessive heat gain from falling solar radiation.
LEDs Semiconductor light emitting devices LEDs are called the light sources of the future. The achieved characteristics of LEDs - luminous efficiency up to 25 Lm/W, watch service life - have already provided leadership in lighting equipment, automotive and aviation technology. LED sources Lights are on the cusp of an invasion of the general lighting market, and we will have to endure this invasion in the coming years.
Due to this overheating, two consequences immediately arise: the discomfort of users and the increased consumption of electrical energy for artificial environmental conditioning. The identification of such problems has given rise to the need to develop new technologies for the production of translucent components, which are mainly sought ideal component: high light transmission; low heat transfer; and low UV transmission.
Currently topical issue is the concern about electricity consumption and the environment. It is not uncommon to see several countries with their legislation reformulated with a marked concern for energy-environmental issues, including the desire for comfort in built environments. Studying on several levels, environmental comfort is considered one of the main goals of architecture: it seeks adequate parameters for designing and evaluating the performance of the built space with the aim of maximizing the user's experience.
The principle of operation of LEDs is fundamentally different from the principle of operation of a conventional incandescent lamp, the current does not pass through the filament, but through a semiconductor chip. That is why LED lamps require constant current to operate. Red, green and yellow LEDs have long been used, for example, in monitors and televisions. With the development of technology, it became possible to also produce blue LEDs (light-emitting diodes in blue). Initially, a combination of red, green and blue LEDs was used to create white glow. But, thanks to the rapid technological progress in the development of LEDs, white color can now be achieved with 1 LED. To do this, the blue LED is coated with a yellowish fluorescent composition, the resulting color will be with a cold tint due to the large flow of blue light (similar to the situation with daylight fluorescent lamps). LEDs, unlike standard lamps, do not give diffused light, but directional light, like reflectors, but at the same time, the angle of the light beam is narrower than that of halogen lamps. To increase it, various lenses and diffusion screens are used. An angle of 120 degrees can be obtained when using LEDs without a housing, as when they are mounted directly on the board without lenses.
The indiscriminate and predatory use of traditional sources and the proliferation of nuclear installations have decisively raised the issue of environmental impact and the limitation of inadequately exploited energy sources. The challenge in the current scenario is to change and replace the traditional consumer behavior of the production and mass consumption model in order to rationalize the use of energy and indicate measures for more responsible use, considering not only the present moment, but also its global impact on the future.
Advantages of using LEDs: LEDs have a high luminous efficacy Lm/W, while standard lamps have a luminous efficiency of 7-12 Lm/W. At the same time, energy consumption remains quite low (40-100mW), so only a few lamps are required for lighting. LED lamps manufactured by the German company Paulmann (Paulmann) consume only 1W of electricity with high light output. LEDs emit almost no heat. However, for high-power lamps, heat sinks are used, but the heat is released and distributed over a very limited area. LEDs have a lifespan of thousands of hours, and after that time, they will still work, although they will give less than 50% of the original light. This corresponds to 11 years of continuous use of the light bulb. Accurate color reproduction due to the absence of UV radiation. Vibration resistant. Possibility of using a longer cable when direct current or alternating current 50 Hz. LEDs are increasingly used in lamps, they act as a light source, and not just as decorative lighting. Application examples: Outdoors, bathroom, kitchen, hallway, living room.
Continuous use of energy is perhaps the largest environmental impact of a building and therefore energy efficient design should be a top priority. This is due to several aspects, including using renewable energy sources, minimizing cooling loads and optimizing daylight.
From an ecological point of view, the building must provide the user, first of all, with a minimum condition of habitation, followed by a continuous sense of well-being. It is noteworthy that with regard to aspects of lighting in architectural design, they should be considered together. This integrated vision also makes it possible to ensure good energy performance of an architecture that, when adapted to the needs of the user, leads above all to a more comfortable and energy efficient environment.
As a result of the global crisis, the problem of energy conservation has become even more urgent all over the world. In this regard, since September 1, 2009, 27 EU countries have already banned the sale of incandescent lamps with a power of 100 or more watts. And already in 2011 in Europe it is planned to introduce an embargo on the sale of the most popular 60-watt light bulbs among buyers. By the end of 2012, it is planned to completely abandon incandescent lamps. The U.S. Congress passed legislation to phase out incandescent light bulbs in 2013. According to these laws, residents of the European Union and the United States will completely switch to energy-saving light sources - fluorescent and LED bulbs. In Ukraine, according to a government decree, the cessation of production and sale of incandescent lamps is expected as early as 2013.
In this sense, it is important to emphasize that in order to achieve energy efficiency in a building, natural lighting must be designed in combination with an artificial lighting system. For, thanks to the optimal use of natural light, the use of artificial light is reduced. So when natural light is sufficient in a given environment, artificial light can be switched off or dimmed.
In the Brazilian context, mainly the use of natural light is reflected directly in the energy spent on air conditioning and artificial lighting. In most Brazilian cities, sky brightness is intense, greatly reducing the use of artificial light in most buildings. Air conditioning costs can also be reduced because natural light produces less heat per unit of light than most artificial light sources, which also reduces the load on the air conditioner.
In some chemical reactions that release energy, part of this energy is directly spent on the emission of light. The light source remains cold (it has ambient temperature). This phenomenon is called chemiluminescence. Almost all of you are probably familiar with it. In the summer in the forest you can see a firefly insect at night. A small green "flashlight" "burns" on his body. You won't burn your fingers by catching a firefly. A luminous spot on its back has almost the same temperature as the surrounding air. Other living organisms also have the property of glowing: bacteria, insects, many fish that live at great depths. Pieces of rotting wood often glow in the dark. Chemiluminescence
Methods of light emission 1. Thermal radiation - radiation of light by a fire flame, the Sun, a wooden torch, a candle, electric incandescent lamps (Lodygin's lamp, Yablochkov's candle, gas lamps, halogen lamps) 2. Electroluminescence - fluorescent lamps, fluorescent lamps, advertising tubes. 3. Cathodoluminescence - the glow of the TV screen, oscilloscopes 4. Chemiluminescence - the glow of fireflies, rotting trees, fish. 5. Radiation of semiconductors when current is passed through them - LED lamps
natural and artificial light sources
Natural light source Natural light sources are those sources that emit light in a natural way. For example: sun, lightning, stars, etc.
Artificial light source Artificial light sources are those sources that man has created.
Several unusual sources
Types of light sources * Electric: Electric heating of incandescent bodies or plasma. Joule heat, eddy currents, electron or ion flows.* Nuclear: isotope decay or nuclear fission. * Chemical: combustion (oxidation) of fuels and heating of combustion products or incandescent bodies. * Thermoluminescent: The conversion of heat into light in semiconductors. * Triboluminescent: transformation of mechanical influences into light. * Bioluminescent: bacterial light sources in wildlife.
Hazardous factors of light sources * Open flame. * Bright light radiation dangerous for the organs of vision and exposed skin. * Thermal radiation and the presence of hot work surfaces that can lead to burns. * High-intensity light radiation that can lead to fire, burns, and injury - laser radiation , arc lamps, etc.* Combustible gases or liquids.* High voltage nutrition.* Radioactivity.
Light sources artificial natural
Ancient time - candles, torches and lamps The very first source of light used by people in their activities was the fire (flame) of a fire. With the passage of time and increasing experience with burning various combustible materials, people have found that more light can be obtained by burning any resinous woods, natural resins and oils and waxes. From the point of view of chemical properties, such materials contain a greater percentage of carbon by mass, and when burned, sooty carbon particles become very hot in the flame and emit light.
Gas lanterns Further progress and development of knowledge in the field of chemistry, physics and materials science allowed people to use also various combustible gases that give off more light when burned. Gas lighting was quite widely developed in England and a number of European countries. A special convenience of gas lighting was that it became possible to illuminate large areas in cities, buildings, etc., due to the fact that gases could be very conveniently and quickly delivered from the central storage (cylinders) using rubberized sleeves (hoses), either steel or copper pipelines, and it is also easy to cut off the gas flow from the burner by simply turning the shut-off valve.
The advent of electric light sources Further progress in the field of invention and design of light sources was largely associated with the discovery of electricity and the invention of current sources. At this stage of scientific and technological progress, it became quite obvious that it is necessary to increase the temperature of the area emitting light in order to increase the brightness of light sources. If, in the case of the use of combustion reactions of various fuels in air, the temperature of the combustion products reaches 1500-2300 ° C, then when using electricity, the temperature can still be significantly increased.
The presentation was prepared by Zhenya Selezova Koroleva Kristina Mamyanov Evgeniy
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