The article deals with the history of the emergence of wool as a subject of entrepreneurship in England. The advantage and peculiarities of the development of this business in the origins of entrepreneurship, gaining world fame and becoming international are defined.
01.05.2024 Volume 3 Issue 4 View more Download
In this work, the growth and development of cotton plants by day was studied for the first time. Exposure to UV rays was discovered to accelerate the growth and development of cotton variety “Tashkent - 6”. With ultraviolet (UV) irradiation, the appearance of fetal elements increases. UV irradiation of cotton bushes leads to an increase in yield up to 55-60%.
01.05.2024 Volume 3 Issue 4 View more Download
This article describes the transport-operational indicators of the city streets, and the transport-operational indicators include the following: Roughness of the surface course of the pavement; Durability of road pavement; Coefficient of friction with wheels; The speed of vehicles.
30.04.2024 Volume 3 Issue 4 View more Download
This article examines the dynamics of retail services offered to the population by commercial banks, in particular, credit services, and also analyzes statistical data on the subject. A number of problems and shortcomings in providing the population with banking services have been identified, and conclusions and suggestions for their elimination have been given.
30.04.2024 Volume 3 Issue 4 View more Download
Currently, wireless communication technologies such as Wi-Fi and Bluetooth are widely used in our daily lives. Their wireless communication technology uses radio waves and uses frequencies allocated to each country. However, this method has problems such as limitations and interference with radio frequency (RF), security, and high cost. The Light-Fidelity (Li-Fi) method, which can solve these problems, has emerged as an alternative. Because the Li-Fi communication method uses visible light, its availability, bandwidth, security, and efficiency are superior to Wi-Fi. In this paper, the actual usability of Li-Fi was confirmed by implementing an audio system using the Li-Fi wireless communication method. The proposed system designed a modulation unit that converts the audio signal into an optical signal, and a demodulation unit that converts the optical signal back into an electrical signal and transmits it to the speaker. Additionally, an audio amplifier was added to amplify the signal. LED was used as a light source, and a solar cell, which is used in solar power, was used as a sensor to detect light signals. As a result of implementing the system, it was confirmed that the audio signal passed through the system using the Li-Fi method and that the appropriate audio signal was output from the speaker. By using a solar cell as a sensor, it can be used for both sensor and solar energy storage. Although it is a basic audio system using Li-Fi, an independent wireless optical communication room can be configured in the future. In addition, it was confirmed that using a laser diode as a light source could be applied to a wider range of fields.
30.04.2024 Volume 3 Issue 4 View more Download
The article provides an analysis of multiplying and dividing devices based on a magnetic transistor amplifier. We consider the amplification mode and the transient process of a magnetic transistor converter, and also provide a description of the operating states of the basic circuit. The proposed scheme is simple, economical, highly reliable, fast and stable. As a result of the research, based on the data obtained, characteristics were constructed on which it can be noted that the rate of change of induction during the operating half-cycle is constant and does not depend on the magnitude of the control signal. When designing functional converters with magnetic transistor pulse-width modulators, the one used in the analysis of one of the proposed circuits, taking into account the dynamic hysteresis loop, can serve as the basis for a preliminary assessment of the conversion accuracy in a given range of input values.
30.04.2024 Volume 3 Issue 4 View more Download
In this work, the temperature dependence of discrete energy states in the silicon band gap was analyzed using a mathematical model of the band gap width of semiconductors depending on the alloying level and the density of states spectrum.
30.04.2024 Volume 3 Issue 4 View more Download
It is known that the occurrence and existence of ferroresonant oscillations at the subharmonic frequency (SHF) in power transmission lines (PTLs) and in power supply systems is extremely undesirable, since they cause ferroresonant overvoltages at various frequencies. At the same time, there is a wide class of nonlinear electrical circuits in which the excitation of autoparametric oscillations (APO) at the SGC frequency forms the basis of frequency-converting devices that serve as secondary power sources. It is shown that three-phase nonlinear systems are, to one degree or another, equivalent circuits for power lines, the main elements of which are: longitudinal compensation capacitors, transverse compensation reactors, and transformers with a nonlinear characteristic. To study the pattern of excitation and maintenance of SGC at frequency (ω/3)in three-phase electroferromagnetic circuits (EFMC), theoretical and experimental studies were carried out on an equivalent model of a three-phase circuit with nonlinear inductance. To analyze the steady-state mode of the SGC at frequency (ω/3), the method of frequency-energy relations was applied. An algebraic equation is obtained that characterizes the steady-state mode of the SGC at frequency ω/3 in a three-phase nonlinear circuit. The frequency-converting properties of nonlinear inductance are also shown. The obtained results of the theoretical study were confirmed by experimental studies.
30.04.2024 Volume 3 Issue 4 View more Download
The article discusses the principles of constructing a new ferromagnetic current converter with an adjustable range in transformer and galvanomagnetic modes and their classification. It is described how to determine the methods for measuring current transducers, as well as the differences between the non-contact method and the contact method. It has been determined that current transducers used in traction power control systems must have advanced measurement functions, adjustable range, linear ramping function, high sensitivity and accuracy, and proportional characteristics even under severe operating conditions. A comparative analysis of the main characteristics of existing current measuring converters showed that transformer and galvanomagnetic measuring converters better meet the requirements of traction power supply control systems.
30.04.2024 Volume 3 Issue 4 View more Download
SCIENCE & INNOVATION