Journal La Multiapp <p>International <strong>Journal La Multiapp</strong> ISSN 2721-1290 (Online) and ISSN 2716-3865 (Print) includes all the areas of research activities in all fields Engineering, Technology, Computer Sciences, A<span class="tlid-translation translation" lang="en"><span class="" title="">rchitect</span></span>, Applied Biology, Applied Chemistry, Applied Physics, Material Engineering, Civil Engineering, Military and Defense Studies, Photography, Cryptography, Electrical Engineering, Electronics, Environment Engineering, Computer Engineering, Software Engineering, Electromechanical Engineering, Transport Engineering, Mining Engineering, Telecommunication Engineering, Aerospace Engineering, Food Science, Geography, Oil &amp; Petroleum Engineering, Biotechnology, Agricultural Engineering, Food Engineering, Material Science, Earth Science, Geophysics, Meteorology, Geology, Health and Sports Sciences, Industrial Engineering, Information and Technology, Social Shaping of Technology, Journalism, Art Study, Artificial Intelligence, and other Applied Sciences.</p> Newinera Publisher en-US Journal La Multiapp 2716-3865 Experimental Study on Sampling Theorem in Signal Processing <p>This practicum is to define the study properties of the sampling theorem. Understand the effect of selecting the sample size and its effect on the signal recovery process. The experiment utilizes a computer or portable workstation to run an examination of the hypothesis reenactment program. From the test information gotten, it can be concluded that the more noteworthy the frequency of the signal to be inspected, the closer the signal will be to the initial signal. The time and frequency of the examining signal are conversely relative. The higher the frequency, the lower the time will be. The magnitude of the amplitude of the output signal is indeterminate.</p> Nyein Mynt Zaw Aung Kyaw Lin Copyright (c) 2020 Journal La Multiapp 2020-12-31 2020-12-31 1 6 1 5 10.37899/journallamultiapp.v1i6.278 Analog Signal and Digital Signal Processing in Telecommunication System <p>The term digital signal is a term from a technology that converts an analog signal into digital data so that the signal can be processed more easily and quickly. The term digital itself is a system that only recognizes two conditions. The two conditions are usually represented by the numbers zero and one, on and off, or others. The smallest unit of digital signal is the bit.</p> Phong Hung Vu Duc Vuong Copyright (c) 2020 Journal La Multiapp 2021-01-31 2021-01-31 1 6 6 11 10.37899/journallamultiapp.v1i6.277 Unconventional Technique for Producing Borosilicate Glass Foam <p><em>The study aims to test an advanced technique but insufficiently valued in the world in the process of experimental manufacture of borosilicate glass foam. It is about the unconventional technique of heating solids by using the microwave radiation converted into heat. The experimental equipment on which the tests were performed was a 0.8-kW microwave oven commonly used in the household with constructive adaptations to be operational at high temperature. The adopted manufacturing recipe was composed of borosilicate glass waste with the addition of calcium carbonate, boric acid and water in different weight proportions. The material was sintered at 829-834 ºC by predominantly direct microwave heating and the optimal foamed product had characteristics similar to those manufactured by conventional techniques (apparent density of 0.33 g/cm3, thermal conductivity of 0.070 W/m•K, compressive strength of 3.1 MPa and a homogeneous microstructure with pore size between 0.7-1.0 mm). The energy efficiency of the unconventional manufacturing process was remarkable, the specific energy consumption being only 0.92 kWh/kg.</em></p> Lucian Paunescu Marius Florin Dragoescu Sorin Mircea Axinte Felicia Cosmulescu Copyright (c) 2021 Journal La Multiapp 2021-01-14 2021-01-14 1 6 12 22 10.37899/journallamultiapp.v1i6.272