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Data Conversion Process
Published in Michael Olorunfunmi Kolawole, Electronics, 2020
There is a strong motivation behind exploring a novel frontier of data processing that could benefit from cutting-edge miniature and power-efficient nanostructured silicon photonic devices. Recent example is photonic accelerator (PAXEL)—a processor that can process time-serial data either in an analog or digital fashion on a real-time basis [1]. Data processing is a way of converting data into a machine-readable form using a predefined sequence of operations. Communications signals can be analog or digital, and information can be transmitted using analog or digital signals. Analog signals are continuously changing in time (or frequency), while digital signals are discrete in time and amplitude. Interchangeability of information transfer allows the development of conversion processes without loss of detail. The challenge is to achieve a high sampling rate and high conversion accuracy in the presence of component mismatch, nonlinearity errors, and noise. Although the electronic circuits required to do this conversion processing can be quite complex, the basic idea is fairly simple. The basic concepts of data conversion and their inherent errors, as well as the choice of the converter types that strongly influence the architecture of the overall system, which are fundamental to the continuing revolution in information technology and communication systems, are explained in this chapter.
Electronic Circuits in Action
Published in Trevor Linsley, Electronic Servicing and Repairs, 2014
The electricity generating stations generate a sinusoidal alternating voltage waveform from an alternator which is usually driven by a steam turbine. A sinusoidal waveform is arepetitive, analogue waveform; repetitive because in the case of the a.c. mains it repeats itself fifty times each second, and analogue because it varies smoothly and continuously between two extremes. In everyday life, analogue systems are all around us. Television, radio and telephone signals are all analogue, the amplifier considered earlier is an analogue amplifier. A car speedometer and fuel gauge are analogue instruments. Analogue electronics is one oftwo main branches of electronics, the other isdigital electronics. Digital signals do not change smoothly and continuously between voltage levels but have two quite definite levels, either on or off. Digital signals are in the form of electrical pulses whose outputs involve only two levels of voltage, called high or low, where high might be +5 V and low 0 V. The termmark-to-space ratio is used in connection with digital signals, particularly square, rectangular and pulse waveforms, and is given by mark-to-spaceratio=marktimespacetime
Background
Published in Russ Martin, Sound Synthesis and Sampling, 2012
Analogue electronics is concerned with signals: audio, video, instrumentation or control signals. These are usually direct representations of the real-world value, but converted in to an electrical signal by some sort of transducer or converter, analogue signals indicate the value by voltage or current. For example, a device for measuring the level of a liquid in a tank might produce a voltage and by connecting this voltage to a calibrated indicator or meter, the level can be monitored remotely. Being able to connect a meter across an analogue circuit and directly measure a voltage is typical of analogue circuitry, and is rarely possible with digital circuits, which normally require more complex equipment to monitor what is going on.
Bioguided fractionation of procyanidin B2 as potent anti coxsackie virus B and Herpes simplex from cypress (Cupressus sempervirens L.)
Published in International Journal of Environmental Health Research, 2022
Safa Rguez, Majdi Hammami, Wissem Aidi Wannes, Ibtissem Hamrouni Sellami
HSV-2 belongs to the Herpesviridae family and Alphaherpesvirinae subfamily. It is a sexually transmitted contagious viral disease responsible for skin and nervous system affections (Wagner and Ulrich-Merzenich 2009). After primary infection, HSV-2 established in sensory dorsal root ganglia. This virus is characterized by pimple vesicular eruptions and it triggers following drop immunity or exposition to sun or stress. Disease is considered benign for healthy subjects and severe for immunocompromised subjects, pregnant women and newborns (Sauerbrei 2016). Treatments used against herpes only reduce viral infection but cannot stop it. The main antiviral drug used against herpes is acyclovir (ACV, ZoviraxR) which is a nucleoside guanosine analogue inhibiting viral DNA polymerase. Valaciclovir (ZelitrexR) is also indicated for curative treatment of genital and labial herpes. Foscarnet (FOS, FoscarvirR) and cidofovir (CDV, VistideR) are also two molecules used as treatment against herpes.
Matter-wave interferometry with atoms in high Rydberg states
Published in Molecular Physics, 2019
The Rydberg-atom interferometer presented here represents an electric analogue of the longitudinal Stern-Gerlach interferometer. It has been implemented using a sequence of microwave pulses to coherently prepare and manipulate selected pairs of Rydberg states. These are interspersed with a pair of electric field gradient pulses to generate spatially separated momentum components. In this scheme a first microwave pulse is used to create a superposition of two circular Rydberg states in helium before inhomogeneous electric fields, in conjunction with a π pulse of microwave radiation, are applied to generate a spatial separation between the two momentum components associated with this superposition. A second microwave pulse then projects the internal states back onto the circular basis states before state-selective detection of the atoms is carried out by pulsed electric field ionisation.
Resonance enhanced multiphoton ionisation (REMPI) detection of Cl(2Pj) atom in the photodissociation of halogenated pyrimidines at 235 nm: role of triplet states
Published in Molecular Physics, 2019
Doddipatla Srinivas, Monali Kawade, Hari P. Upadhyaya
In the case of 2,4,6-trichloropyrimidine, there are at least three dissociating Cl atom which can give rise to three different angles with respect to initial direction of transition dipole moment. In 2,4,6-trichloropyrimidine, the main excitation is through S1 and S2 which are of nπ* and ππ* in nature. The transition dipole moment for S1 state lies perpendicular to the molecular plane whereas for S2, it is in the molecular plane towards the y-axis. In this situation, there exist a wide range of the angles between the transition dipole moment and the dissociating Cl atoms. For S2 state, it comes out to be 90°, 28° and (180-28)°. However, in case of trifluoro analogue, the wide ranges of angles do not exist due to presence of only one Cl atom. However, the molecule has mixed transition, namely perpendicular (S1) and parallel (S2). Hence, due to several intersystem crossing and multiple channels for the formation of Cl atom, the product angular distribution becomes isotropic.