ultrasonic frequency
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LWT ◽  
2022 ◽  
Vol 153 ◽  
pp. 112435
Author(s):  
Yanhua Ding ◽  
Yaoyao Wang ◽  
Wenjuan Qu ◽  
Xiaofeng Ren ◽  
Feng Lu ◽  
...  

2021 ◽  
Vol 18 (3) ◽  
pp. 266-277
Author(s):  
Sumit Desai ◽  
Dilip Choudhari

This work presents design and fabrication of efficient and economical ultrasonic utensil cleaning machine. Electrical energy is converted into Mechanical energy by transducer. Transducer vibrates with ultrasonic frequency supplied to it by the frequency producer. These vibrations produce cavitation bubbles in the solvent/water. The size of the bubbles is in micron range. The mass of the cavitation bubbles depend on the rate of recurrence of the transducer. These bubbles act as scrubber which scrub the surface of utensil thus removing the soils/dirt stick on it. The size of the bubble is so small it does not cause any damage to the surface of utensil. Higher the frequency, more homogeneous will be the cleaning. Rinsing is provided within the system which will make it more compact. To keep the contaminants away from the cleaned surface, sweep frequency is used. Rotation to the basket is given by the motor. This rotation helps to reduce the cycle time and also dry the surface of utensil by centrifugal action. So when the utensil is removed from the basket it is ready for use. By this technology cycle time will be reduced drastically. Without any human efforts it can clean the dirtiest stains from the oily utensils. All types of utensils can be cleaned whether it is ceramics, glass, copper, wood, aluminum, stainless steel, etc. This cleaning process is more hygienic and can clean more efficiently compared to conventional cleaning.


2021 ◽  
Vol 15 (2) ◽  
pp. 154
Author(s):  
Herliati Rahman ◽  
Satrio Nur Pambudi ◽  
Wahyu Endrunaka

Gingerol is a chemical compound found in red ginger, with pharmaceutical use as an analgesic drug. Generally, gingerol separation in ginger uses the Soxhlet extraction method, but this process has a weakness. It requires a long process and unsatisfactory yield. This research aims to study ultrasonic frequency effect on increasing gingerol yield in the extraction process. The variables studied were extraction times with variations of 30, 60, 90, and 120 minutes. In addition, the ultrasonic effect was also observed with variations in the ultrasonic frequency of 40 and 50 kHz compared to the solvent extraction method. This study used 70% (v/v) ethanol as a solvent and an operating temperature of 50 ºC as fixed variables.Furthermore, it used a rotary vacuum evaporator at a pressure of 350 mmHg to separate the resulting gingerol extract. Qualitative sample analysis used Thin Layer Chromatography (TLC) and scanning electron microscope (SEM) while quantitative analysis used high-performance liquid chromatography (HPLC), Waters Alliance e2695 brand with X-Terra RP18 column 100 x 4.6 mm, five μm to determine the total gingerol extract. The results showed that ultrasonic power had a significant effect on the results obtained, with the highest yield was 24.71% at the ultrasonic frequency of 50 kHz with an extraction time of 120 minutes.


Author(s):  
Michal Cieslak ◽  
Christoph Kling ◽  
Andrea Wolff

Prolonged exposure to airborne ultrasound in a workplace can have a detrimental influence on a worker’s well-being. Given the ever-increasing use of ultrasonic industrial equipment, it is of vital importance—and may also be regulated by law—to monitor ultrasound exposure during a normal workday as part of workplace risk assessment. However, the devices currently utilized exhibit limitations with regard to both their operational frequency and their portability (wearability). In this paper, the first prototype of a high-frequency and ultrasound personal exposimeter is presented in the light of the latest national and international standards governing high-frequency and ultrasonic noise measurement in the field of occupational health monitoring. The prototype was tested in the laboratory environment in order to assess its sound level detection capabilities in both the audible and ultrasonic frequency ranges. Several common industrial scenarios—including an ultrasonic welding machine, an ultrasonic cleaning bath, and a compressed air gun—were simulated in a laboratory environment. For each simulated set-up, a corresponding high-frequency or ultrasonic signal was fed through a specially prepared generation chain. Each experimental scenario was initially surveyed with an ultrasound level meter previously tested up to 100 kHz. This was followed by a measurement with the prototype. For this study, the simulated sound signals varied between 10 kHz and 40 kHz on the frequency scale and between 60 dB and 90 dB in amplitude. The portability of the prototype, which may be required to be worn throughout an entire workday (e.g., 8 h), was also considered. All the experiments were performed on a customized ultrasound measurement set-up within a free-field environment located at the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Germany. Results obtained suggest a good agreement between the measurements performed with both devices in the louder areas of the sound fields produced. Because the overall measurement uncertainty is highly dependent on the specificity of the individual measurement set-up and measurement procedure, an uncertainty budget estimated for the prototype considers electro-acoustical contributions only.


2021 ◽  
Vol 7 ◽  
pp. 31-35
Author(s):  
B. Aishwarya ◽  
S. Lakshmi Sree ◽  
R. Balasubramanian

Dentistry has undergone significant improvement with a lot of changing concepts involving novel surgical tools over the past two decades. Piezoelectric surgery, also popularly called as piezosurgery (PS), is a rapidly evolving technique of bone surgery which is gaining importance because of its ability to place osteotomy cuts with absolute precision and confidence, especially near the vital structures. Piezosurgical device functions with an ultrasonic frequency (25–29 KHz) resulting in microvibrations in the range of 60–200 µm/s enabling bone cutting that is secured and accurate preserving the underlying neurovascular elements along with improved visibility through bloodless surgical site and thorough debridement using internal irrigation system. Till date, PS has seen wide applications in various disciplines of medicine. In the field of dentistry, PS has emerged as a promising technical modality in bone graft harvesting, alveolar ridge expansion, sinus lift procedures, osteogenic distraction, and endodontic and periodontal surgeries. The present review addresses the efficiency of PS comparing it with the traditional dental surgical equipment. The advantages, limitations, and biological effects of PS as well its various applications in dentistry have also been discussed.


Author(s):  
C Balasubramaniyan ◽  
K Rajkumar ◽  
S Santosh

NiTiCuZr shape memory alloys (SMA) outperform ternary and binary SMA alloys in terms of functional fatigue and higher temperature performance due to their high cyclic stability and transformation temperatures. Owing to the impairment of the shape memory effect during processing, it is difficult to select a manufacturing process for obtaining design functionality with the required dimensions and surface roughness. In this work, a high-temperature NiTiCuZr SMA was machined using an ultrasonic vibration assisted wire electric discharge machine (USV-WEDM). The machining was conducted using various parameters with a constant ultrasonic vibration of 20 kHz provided on a wire-electrode to evaluate surface roughness (Ra) and material removal rate (MRR). Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray analysis (EDX) were utilized to examine the surface integrity and chemical composition of the machined surfaces. MRR increased by 62% with a steady increase in pulse-on time ( Ton) and applied current ( I), whereas increasing levels of parameters such as pulse-off time ( Toff) and servo voltage (SV) reduced surface roughness ( Ra) by 69%. The results reveal that tool vibration at ultrasonic frequency reduces the surface roughness and improves the material removal rate of the machined NiTiCuZr SMA as compared to that of non-ultrasonic assisted machining conditions. SEM-EDX investigation reveals that the formation of re-solidification and oxide layers during NiTiCuZr machining at high machining parameters results in increased hardness and surface roughness. USV-WEDM is a suitable process for machining SMA alloy without adversely impacting SMA properties.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1139
Author(s):  
Hongguang Yang ◽  
Jianchun Yan ◽  
Hai Wei ◽  
Huichang Wu ◽  
Shenying Wang ◽  
...  

In view of the poor effectiveness of existing potato cleaning methods in China and reflecting the findings of a research analysis of basic sizes and types of impurities on potato tubers, a gradient cleaning method for potato based on a multi-step dry-cleaning and wet cleaning operation was proposed. The method mainly consists of dry-cleaning and wet cleaning. The dry-cleaning stage, which combines vibration and brushing, could effectively remove impurities such as residual rhizomes, peeled potato skin, and large pieces of soil and crushed stone from the surface of potato tubers. The wet cleaning stage adopts the gradient cleaning method of pre-cleaning, rough cleaning and fine cleaning, which could further remove soil and crushed stone attached to the surface and hidden in the sprout eyes of potato tubers. The optimal parameter combination for the gradient cleaning method was determined as follows. The potato feeding amount was 3 t/h, the speed of the rubber chain rod mechanism was 25 r/min, the speed of the first and third brush roller was 40 r/min, the speed of the second and fourth brush roller was 56 r/min, the moving speed of the immersion mechanism conveying net chain was 0.04 m/s, the speed of the brush roller in the high pressure spray and brush roller combination mechanism was 40 r/min, the ultrasonic power was 1200 W, the ultrasonic frequency was 33 kHz, the bubble intensity was 300 L/min, and the moving speed of the conveying net chain in the ultrasonic and bubble combination mechanism was 0.05 m/s. Taking the impurity removal rate and damage rate of potato tuber as the test indexes, a potato cleaning performance test was carried out under the optimal parameters combination. The results showed that the average impurity removal rate and damage rate of potato tubers were 99.05% and 2.48%, respectively. Additionally, the operational performance fully met the requirements for potato cleaning. This study provides a new method for potato cleaning in China and can also provide a reference for cleaning other root and tuber crops.


2021 ◽  
Vol 845 (1) ◽  
pp. 012075
Author(s):  
E S Krasnikova ◽  
N L Morgunova ◽  
A V Krasnikov ◽  
A S Rykhlov ◽  
V A Babushkin ◽  
...  

Abstract Young lamb has high nutritional properties due to its high protein, amino acids, vitamins and microelements content. However, the specific odor and the high fat pour point are the main obstacles to the industrial use of lamb. The purpose of our research was to study the physical and chemical characteristics of raw lamb after ultrasonic salting and to select the optimal processing conditions and their economic justification. Experimental samples were salted in the devices UOM - 2 and PSB - Gals at 35 kHz ultrasound frequency, as well as using an ultrasonic submersible emitter at 26 kHz. Ultrasonic treatment has led to an increase in the pH and moisture content of the raw material, as well as in product yield. With an increase in the salting time, the water activity (Aw) decreased. Based on the results of physicochemical samples studies and comparative analysis of the economic efficiency, a submersible ultrasonic emitter with an ultrasonic frequency of 26 kHz and a salting duration of 12 hours was recommended for lamb delicacies salting.


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