Time frequency analysis of peking gamelan

The tone of peking 1, 2, 3, 5, 6, 1’ was investigated using time-frequency analysis (TFA). The frequencies were measured using PicoScope oscilloscope, Melda analyzer in Cubase version 9 and Adobe version 3. Three different approaches for time-frequency analysis were used: Fourier spectra (using PicoScope), spectromorphology (using Melda analyzer) and spectrograms (using Adobe). Fourier spectra only identify intensity-frequency within entire signals, while spectromorphology identify the changes of intensity-frequency spectrum at fixed time and Adobe spectrograms identify the frequency with time. PicoScope reading produces the spectra of the fundamental and overtone frequencies in the entire sound. These overtones are non-harmonic since they are non-integral multiples of the fundamental. The fundamental frequencies of peking 1, 2, 3, 5, 6 were 1066Hz (C6), 1178Hz (D6), 1342Hz (E6), 1599Hz (G6) and 1793Hz (A6) respectively while peking 1’ was 2123Hz (C7) i.e. one octave higher than peking 1. Melda analyzer reading proved that all peking sustained the initial fundamental frequency and overtone at t=0 until 2s. TFA from Adobe reading provides a description of the sound in the time-frequency plane. From TFA, peking 1, 2 and 6 exhibited a much gentler attack and more rapid decay than peking 3, 5 and 1’

Timbre spectrum of gamelan instruments from four Malay gamelan ensembles

Gamelan in general is categorized as a group of gongs. This traditional Malay gamelan ensemble is in a slendro scale i.e. five notes per octave. The rhythms, pitch, duration and loudness classify the various groups of gongs such as bonang, kenong, gender, peking and gambang. The cast bronze peking, kenong and bonang were chosen from a range of Malay gamelan ensemble from Universiti Malaysia Sarawak (UNIMAS), Universiti Putra Malaysia (UPM), Universiti Kebangsaan Malaysia (UKM) and Universiti Teknologi Mara (UiTM). The sounds were recorded by PicoScope Oscilloscope. The PicoScope software displays waveform and spectrum in time and frequency domain respectively. The peking lowest and highest frequencies from UiTM were 293 Hz and 1867 Hz, from UPM were 644 Hz and 1369 Hz, from UKM were 1064 Hz and 2131 Hz and from UNIMAS were 1072 Hz and 2105 Hz respectively. The kenong lowest and highest frequencies from UiTM were 259 Hz and 463 Hz, from UPM were 294 Hz and 543 Hz, from UKM were 300 Hz and 540 Hz and from UNIMAS were 293 Hz and 519 Hz respectively. The fundamental frequencies of bonang from UPM were higher than that of UKM, UiTM and UNIMAS. The harmonics were not successive but interrupted by another frequency. The harmonics of each bonang was similar except for gamelan from UKM

A Review On Electrospun Short Fiber Production

Nanotechnology has become the interest of researchers in recent years for their unique properties of submicron scale materials. Nanotechnology also consists of nanofibers made from natural or synthetic polymers which can be electrospun into ultra-thin continuous fibers. These nanofibers are versatile as it can be found in various applications such as in filtration, affinity membranes, tissue engineering, biosensors, scaffolds, drug delivery and fiber reinforcement. Over the years, many researchers have reported various methods used to produce short electrospun fiber by means of ultrasonication, mechanical cutting, UV cutting, precipitation method, microtome cutting, cryo-microcutting, cryogenic milling, ball milling, and razor blade cutting under liquid nitrogen. The aim of this paper is to provide a review on electrospun short fiber production which elaborates more on the scission methods of the continuous as-spun fibers. The literature shows that several methods have been proposed and utilized, with varying degrees of success. Overall, it can be concluded that further research is needed to fully understand the complexities of this area and to develop a more effective approach

A Review On Electrospun Short Fiber Production

Nanotechnology has become the interest of researchers in recent years for their unique properties of submicron scale materials. Nanotechnology also consists of nanofibers made from natural or synthetic polymers which can be electrospun into ultra-thin continuous fibers. These nanofibers are versatile as it can be found in various applications such as in filtration, affinity membranes, tissue engineering, biosensors, scaffolds, drug delivery and fiber reinforcement. Over the years, many researchers have reported various methods used to produce short electrospun fiber by means of ultrasonication, mechanical cutting, UV cutting, precipitation method, microtome cutting, cryo-microcutting, cryogenic milling, ball milling, and razor blade cutting under liquid nitrogen. The aim of this paper is to provide a review on electrospun short fiber production which elaborates more on the scission methods of the continuous as-spun fibers. The literature shows that several methods have been proposed and utilized, with varying degrees of success. Overall, it can be concluded that further research is needed to fully understand the complexities of this area and to develop a more effective approach

The frequency spectrum and time frequency analysis of different violins classification as tools for selecting a good-sounding violin

This work evaluates four violins from three distinct manufacturers, notably Eurostring, Stentor, and Suzuki, using a scientific approach. Eurostring1 and Eurostring2 were the names given to the two Eurostring units. The purpose of this study is to identify elements in various violins that could be used as tools for selecting a pleasant-sounding violin by having them classified by a professional violinist. The signal’s time varying frequency was evaluated using a frequency spectrum and a time frequency plane, and the combination of frequency spectrum and time frequency domain is utilised. PicoScope oscilloscopes and Adobe Audition version 3 were used to record the acoustic spectra in terms of time and frequency. The time frequency plane is identified, and time frequency analysis (TFA) is produced by Adobe Audition spectrograms. The sound was processed in order to generate Fast Fourier Transform analysis: Fourier spectra (using PicoScope) and spectrograms (using Adobe Audition). Fourier spectra identify the intensity of the fundamental frequency and the harmonic spectra of the overtone frequencies. The highest frequencies that can be read are up to and including the 9th overtone. All violins have a constant harmonic overtone pattern with an uneven acoustic spectrum pattern. Eurostring1 showed inconsistent signal in the string G with 6th and 7th overtone missing, whereas Eurostring2 lack of the 6th overtone. Among the string D, only Eurostring1 display an exponential decay for the overtone. All the string A except for Suzuki showed nice and significant peak of fundamental and overtone. Stentor displays up to the 5th overtone. Among the string E, Suzuki showed inconsistent harmonic peak intensity. TFA revealed that the fundamental frequency of string E for Eurostring1 was lower than the first overtone. Only Eurostring1 has an uneven decay for the overtone frequency, whereas Eurostring2 exhibits a large exponential decay for the overtone frequency

Time Frequency Analysis of Peking Gamelan

The tone of peking 1, 2, 3, 5, 6, 1’ was investigated using time-frequency analysis (TFA). The frequencies were measured using PicoScope oscilloscope, Melda analyzer in Cubase version 9 and Adobe version 3. Three different approaches for time-frequency analysis were used: Fourier spectra (using PicoScope), spectromorphology (using Melda analyzer) and spectrograms (using Adobe). Fourier spectra only identify intensity-frequency within entire signals, while spectromorphology identify the changes of intensity-frequency spectrum at fixed time and Adobe spectrograms identify the frequency with time. PicoScope reading produces the spectra of the fundamental and overtone frequencies in the entire sound. These overtones are non-harmonic since they are non-integral multiples of the fundamental. The fundamental frequencies of peking 1, 2, 3, 5, 6 were 1066Hz (C6), 1178Hz (D6), 1342Hz (E6), 1599Hz (G6) and 1793Hz (A6) respectively while peking 1’was 2123Hz (C7) i.e. one octave higher than peking 1. Melda analyzer reading proved that all peking sustained the initial fundamental frequency and overtone at t=0 until 2s. TFA from Adobe reading provides a description of the sound in the time-frequency plane. From TFA, peking 1, 2 and 6 exhibited a much gentler attack and more rapid decay than peking 3, 5 and 1’

The Frequency Spectrum and Time Frequency Analysis of Different Violins Classification as Tools for Selecting a Good-Sounding Violin

This work evaluates four violins from three distinct manufacturers, notably Eurostring, Stentor, and Suzuki, using a scientific approach. Eurostring1 and Eurostring2 were the names given to the two Eurostring units. The purpose of this study is to identify elements in various violins that could be used as tools for selecting a pleasantsounding violin by having them classified by a professional violinist. The signal’s time varying frequency was evaluated using a frequency spectrum and a time frequency plane, and the combination of frequency spectrum and time frequency domain is utilised. PicoScope oscilloscopes and Adobe Audition version 3 were used to record the acoustic spectra in terms of time and frequency. The time frequency plane is identified, and time frequency analysis (TFA) is produced by Adobe Audition spectrograms. The sound was processed in order to generate Fast Fourier Transform analysis: Fourier spectra (using PicoScope) and spectrograms (using Adobe Audition). Fourier spectra identify the intensity of the fundamental frequency and the harmonic spectra of the overtone frequencies. The highest frequencies that can be read are up to and including the 9th overtone. All violins have a constant harmonic overtone pattern with an uneven acoustic spectrum pattern. Eurostring1 showed inconsistent signal in the string G with 6th and 7th overtone missing, whereas Eurostring2 lack of the 6th overtone. Among the string D, only Eurostring1 display an exponential decay for the overtone. All the string A except for Suzuki showed nice and significant peak of fundamental and overtone. Stentor displays up to the 5th overtone. Among the string E, Suzuki showed inconsistent harmonic peak intensity. TFA revealed that the fundamental frequency of string E for Eurostring1 was lower than the first overtone. Only Eurostring1 has an uneven decay for the overtone frequency, whereas Eurostring2 exhibits a large exponential decay for the overtone frequency

Scission of electrospun polymer fibres by ultrasonication

In this work we show that sonication alone can be used to scission bulk electrospun membranes into short fibres. The mechanism of such scission events is bubble cavitation stimulated by the ultrasonic probe, followed by bubble implosion. The tendency of polymer nanofibres to undergo failure by such a scission process appears to primarily depend on the ductility of the polymer, with brittle, electrospun polymer membranes such as poly(styrene) and poly(methyl methacrylate) readily producing short fibres of approximately 10 μm length. More ductile polymers such as poly(l-lactide) or poly(acrylonitrile) require additional processing after electrospinning and before sonication, to make them conducive to such sonication-based scission. Both the initial diameter of the fibres and the degree of nanofibre alignment of the electrospun membrane influence the final length of the resultant short fibres. It was found that the chemical and physical properties of the short nanofibres were unaltered by the sonication process. We are thus able to demonstrate that sonication is a promising method to produce significant quantities of short fibres of nanometre diameter and microns in length

Optical, Electrical and Structural Investigation on Different Molarities of Titanium Dioxide (TiO2) via Sol-Gel Method

Titanium dioxide (TiO2) solution having different molarities were synthesized and deposited on glass substrates by using sol-gel spin-coating method. The variation in thickness, optical, electrical and structural properties of TiO2 thin films were investigated by surface profiler (SP), UV-Vis spectroscopy, two-point probes and atomic force microscopy (AFM), respectively. The result show that the thickness of TiO2 thin film increases as the molarities increases. The optical band gap energy decreases from 3.78 eV to 3.07 eV as the TiO2 molarities increases from 0.01M to 0.20M. The maximum value of the absorption coefficient was 16.27 x 104 cm-1 at 0.20M with surface roughness of 21.45 nm. Thin films deposited with 0.01M show lower absorption coefficient (3.87 x 104 cm-1) within visible region with surface roughness of 5.21 nm. The improvement in optical and structural properties of TiO2 thin films affects the electrical properties as the highest conductivity 9.62 x 102 S/m is obtained by 0.20M