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Photonic Nanodevices and Technologies against Light Pollution
Published in Tuan Anh Nguyen, Ram K. Gupta, Nanotechnology for Light Pollution Reduction, 2023
Elisangela Pacheco da Silva, Elizângela Hafemann Fragal, Ederson Dias Pereira Duarte, Sidney A. Lourenço, Edvani C. Muniz, Thiago Sequinel, Rafael Silva, Eduardo José de Arruda, Vanessa Hafemann Fragal
Currently, the evolution of light bulbs has been very fast. After incandescent lamps came neon, fluorescent, halogen, and sodium vapor, we are unveiling LED, OLED, and Quantum Dot Light-Emitting Diodes (QLED) lamps. The neon lamp was created in 1912 by the French chemist Georges Claude and was widely used in signs, in addition to being decorative. In 1938, the fluorescent lamp (made with argon and mercury gas, created by Nikola Tesla), arrived on the market. This model emits more energy in the form of light than heat, which also makes it more economical, savings of around 75% in its consumption. The halogen dichroic lamp appeared 20 years later – another type of incandescent lamp that contains cheap halogen elements such as bromine or iodine, being still more efficient and economical due to extended durability. However, it generates more heat than other lamps, and this increases energy consumption [21].
Explosives and blasting
Published in Ratan Raj Tatiya, Surface and Underground Excavations, 2013
Condenser discharge types (fig. 5.9(c)) of exploders are designed for multi-shot firing. Their basic source is either a low voltage dry cell battery or an electromagnetic generator. When a low voltage battery is used, first of all, the low voltage is converted to high voltage through DC to DC converter. The high voltage so generated charges the capacitor. When capacitor is fully charged a neon lamp indicates it. The voltage is discharged to the external blasting circuit connected to the exploder. It is light in weight and compact in size comparing with the magneto type of exploders of the same capacity. It is easy to operate but discharge of dry battery may affect its performance. One of its drawbacks is that the voltage from the capacitor is not fully discharged to the external circuit and some residual voltage remains in the capacitor, which in turn, may fire another circuit accidentally. The peak current can become high if few shots are fired, thereby causing the fuse head explosion and side burst of the detonators.
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Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[general] Many objects can be included in the list describing objects that emit visible light. Next to visible all object emit infrared radiation as a function of their temperature, when the temperature becomes high enough, the wavelengths associated with the supplied energy reduce to the visible. One example of visible light emitted from a warm object is the use of electric heater coils and the incandescent lamp. Normal room temperature visible light emitters are found in phosphors and LEDs. The velocity of light in media is frequently a function of wavelength and for a broad spectral source this may result in dispersion. The Sun is the most well-known light source, mechanism of action based on nuclear reactions and generated plasmas. Since the Sun is primarily composed of helium (He) and hydrogen (H2), at a temperature of 5780 K, proving the fuel and operating conditions to power a nuclear reactor (i.e., fusion reactor), fusing hydrogen with helium. The electromagnetic spectral emissions from the Sun span an extensive range, approximately from less than 100 nm to about 1 mm. Next to the solar electromagnetic radiation, the nuclear events also produce charged particle emissions. Chemical reactions can produce light as well, the firefly being the most well-known example of this phenomenon. Other examples of light sources are fond in electric discharge (neon lamp, lightning) and electric potential. The emission of light resulting from a changing electrical potential is for instance obtained by the rapid unwinding of adhesive tape, generating a high electric field at the point of separation, which causes electrons to be accelerated and produce light at very short wavelength. Generation of light adheres to the law of conservation of energy (see Figure L.100).
Ignition Diagnostics in EGR- and Air-diluted Methane/Air Mixtures Using Spark Induced Breakdown Spectroscopy
Published in Combustion Science and Technology, 2022
Laura Merotto, Thomas Kammermann, Patrik Soltic
The light emitted by the spark plasma is collected through a lens system through sapphire windows and transferred to the spectrometer slit, as sketched in Figure 2. A slit width of 100 μm is used throughout this study. Wavelength calibration spectra have been captured from a mercury neon lamp. A grating of 150 mm−1 is used on the Princeton Instruments spectrograph with a focal length of 320 mm. An intensified CCD camera (PCO DiCam Pro) with a detector size of 1280 × 160 pixels is used to collect the spectra, with a resulting spectral resolution of 1.7 nm. A trigger box is used to trigger the intensified CCD camera after the breakdown phase, using the secondary current as trigger input. The output signal of the comparator has an intrinsic delay of 50 ns with respect to breakdown occurrence, but allows overcoming the jitter with respect to the ignition signal. This ensures that the chosen gate timing with respect to the breakdown (time = 0) remains the same within a measurement series.
Environmental effect of CI engine using microalgae biofuel with nano-additives
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Vijayan Venkatraman, Sivachandran Sugumar, Saravanan Sekar, Sivakumar Viswanathan
The pour point is the temperature at which the oil in solid form starts to melt or pour. In cases, where the temperatures fall lower the melting point, the complete fuel system with all fuel lines and the fuel tank is needed to be heat. The temperature at which the oil starts to freeze is known as the cloud point. However, operating an engine at temperatures lower than the oil’s cloud point requires heating in order to avoid waxing of the fuel. The cloud point is proposed for use only to oils, which are translucent in layers with 40 mm thickness and have cloud point below 400°C. The pour point is proposed for use to any petroleum oils. The refrigeration bath can be operated above room temperature to below −300°C. Keep the sample to be tested in the glass container, fit the rubber cork and keep vertically in the jacket provided. In case of test, temperature is below 0°C or up to −300°C. Fill the jacket around glass jar with a little amount of ethyl alcohol for appropriate contact of cooling media. Fit the thermocouple pin in rubber cork up to the center of the glass jar. Put on the main switch, Red neon lamp specify its operation. The cooling will take place within 30 to 40 min after the start of the refrigeration system. No significant differences were observed in the cloud and pour point due to the addition of nanoparticles in the biodiesel (Table 2). This indicates that the addition of ZrO2 nanoparticles does not have any significant effect on the cold temperature properties of biodiesel, and no strategic difference is required in the cold handling of the modified fuels.