https://americanjournal.org/index.php/ajtas/issue/feed American Journal of Technology and Applied Sciences 2022-09-16T09:51:13+00:00 Open Journal Systems <p>American Journal of Technology and Applied Sciences is an peer reviewed international, open access journal. This journal publishes the articles in the field of Technology and Applied Sciences. Authors are requested to submit their original research for the double blind peer reviewed journal.</p> <p><strong>ISSN (E):</strong> 2832-1766 <strong>JIF:</strong> 7.235</p> https://americanjournal.org/index.php/ajtas/article/view/65 SYNTHESIS AND CHARACTERIZATION OF SrAl2O4: Eu, Dy NANOMATERIALS 2022-09-16T09:48:19+00:00 Victor Kadenge victorkadenge76@gmail.com <p>One purpose of this study is to describe current advances made mostly in preparation of luminescence nanoparticles based on a study that has been published. In outlining the benefits and limitations of various synthesis methods, we highlight recent advances on SrAl2O4: Eu, Dy nanoparticles. Such durable substance has various advantages over its precursors, including being more stable, efficient, and much less poisonous. Its design of an efficient synthesis process for SrAl2O4 dopant particles. As a result, the average particle size ranges between 20 and 100 micrometers. For contemporary usage that require semi nanoparticles, the high particle diameter is constraining. Its resulting luminescence emission is heavily influenced by the morphology and shape, which may be adjusted by modifying the control parameters. As a result, substantial effort like the sol-gel technique, hydrothermal synthesis, laser synthesis, combustion fabrication, and solid country reaction, has acquired quite a few interest as a result of this. A lot of those methods, even though, are incompatible to enormous production and sustainable requirements. strong synthesis values, in general between 1300 and 1900 °C, with prolonged processing instances are required in the industrial processing of distinctly crystalline powders, especially for strong kingdom reactions has gone into developing new ways for obtaining nanoparticles while minimizing time-consuming, difficult, expensive, or inefficient preparation stages, as well as intrinsic toxicity or elemental shortage. Furthermore, the applicability of lasting luminous nanoparticles photovoltaic cells, biomedical scanning and identification, and safety encryption has piqued interest. Moreover, we discuss the production, characteristics, the uses of luminescent substances, as well as the problems and future of these substances.</p> 2022-09-16T00:00:00+00:00 Copyright (c) 2022 https://americanjournal.org/index.php/ajtas/article/view/66 TECHNOLOGICAL CLASSIFICATION OF UNDERGROUND EXCAVATION WORKS IN GEOTECHNICAL MONITORING SYSTEMS 2022-09-16T09:51:13+00:00 Djaksimuratov Karamatdin Mustapaevich Djaksimuratov@mail.ru Joldasbayeva Aysulu Baxitbay qizi Joldasbayeva@mail.in Bayramova Minevvar Axmet qizi Bayramova@mnanil.uz Tolibayev Erlan Amangeldi o’g’li Tolibayev@mail.uz Maulenov Nurlibek Axmet o’g’li Maulenova@mail.uz <p>Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing (FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating (FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.</p> 2022-09-23T00:00:00+00:00 Copyright (c) 2022