Papers by Keyword: Ultrasonic

Abstract: Nano-ZnO with high photocatalytic performance was prepared by paralled flaw precipitation method under ultrasonic radiation with Zn(NO₃)₂·6H₂O and NH₃·H₂O as raw materials. The prepared samples were characterized by XRD, SEM and TG/DTA. The decolorization of methylene blue solution as model reaction, the effect of calcining temperature on the structure and photocatalytic performance of the samples were investigated. The results show that nano-ZnO with well crystal property and uniform size distribution, prepared by calcining the precursor at 300 °C for 2 h, had the average diameter of about 38 nm. When 100 mL methylene blue solution with 10 mg/L of mass concentration is treated with the nano-ZnO photocatalyst for 60 min, the decolorizing efficiency of the methylene blue solution reached 62.5 %.

Abstract: Experimental study on the ultrasonic, Fenton law separate and composite handle direct blue-B2RL dyeing wastewater of main influence factors and treatment effect. Experimental results show that ultrasonic Fenton recombination method > Fenton> ultrasound treatment effect alone . Complex legal pH values, while ultrasonic-Fenton ultrasonic radiation dosing the amount of H₂O₂ and time and other factors were studied to determine the best experimental conditions.The best experimental conditions is :the dosing the amount of H₂O₂ 3ml/L, pH=3.

Abstract: Coal mine roadway deformation have a significant impact on coal mine production. Based on the Arduino microcontroller system and ultrasonic distance sensor, through temperature compensation and system fixes, designed a roadway deformation monitoring system which is high accuracy, low price and simple operation. Monitoring results through the LCD display, and SD card for data storage, the system achieved real-time monitoring of roadway deformation. The system was actually tested in coal mine, and achieved good monitoring results.

Abstract: Sapphire/metal soldering joints are widely needed in various optical instruments. Traditional soldering methods are expensive and time consuming, because they usually involve a sapphire surface metallization procedure and a vacuum soldering procedure. In this study, we sealed infrared sapphire windows using a novel ultrasonic soldering method in the ambient atmosphere, with Sn-Zn-Al alloy as the solder. The wetting and bonding at the sapphire/solder and solder/metal-tube interfaces were realized by ultrasound. The microstructure of the joints was revealed by means of scanning electron microscope (SEM). The gas impermeability of the samples was investigated. This new method is very simple and cost-saving. The reliability of the samples made by this new method is equal to that made by traditional method. This is the first application of the ultrasonic interfacial deposition brazing and soldering (UIDBS) method to a practical device. We hope this method to be applied to other optical devices.

Abstract: For joining and cutting non-woven fabrics, an ultrasonic wide-blade horn is expected to be used effectively. During the joining and cutting process, this horn can work as the punch in the punching and blanking systems. The performance of a wide-blade horn is normally relevant to the resonance at the operating frequency, the vibration amplitude, and the uniformity of the amplitude on the output surface. In this study, an ultrasonic wide-blade horn is optimally designed and fabricated for joining and cutting non-woven fabrics, and it is tuned to operate at 20 kHz, the resonant frequency of the converter. Analytic and experimental results show that based on the modal and harmonic response analysis and repeated tuning, the wide-blade horn could be optimally designed and fabricated. The resonant frequency of the developed horn was 19,979 Hz, and the amplitude uniformity of the output surface was 76%.

Abstract: In the light of application requirements for non-contact measurement, this paper puts forward a non-contact measuring device. It generates the ultrasonic through electrical way with SCM detecting echo, the timer detecting ultrasonic transmitting and receiving time difference. Then it carries out the non-contact measurement of distance, and displays on LCD. The device can be used in many aspects, such as alarm, data monitoring, etc

Abstract: Cellulose sponge has the characteristic of porous and spongy. It’s difficult to strip in conventional processing. This paper describes a process using ultrasonic aided in solution of thiourea dioxide and sodium hydroxide. The cellulose sponge can be faster and better handled in this process. It will have a better stripping effect. And the optimization parameter of ultrasonic process is described for: thiourea dioxide 30 g/l, sodium hydroxide 40 g/l, the time of 10 min, the temperature of 70 °C. Under the condition of this operation, cellulose sponge stripping rate was 98.8%, the breaking strength loss rate was 27.6%.

Abstract: In order to reduce the production cost of biodiesel, the transesterification process under ultrasound-assisted condition is studyed in this paper by using heterogeneous solid base catalyst NaAlO₃/Al₂O₃ instead of the traditional homogeneous catalyst. Through one-factor experimentation, ultrasonic frequency, oil-alcohol molar ratio, catalyst amount and reaction time on the yield of biodiesel are examined. Transesterification conditions are optimized through orthogonal experiment and the effect order of four factors is as follows: ultrasonic frequency >molar ratio of methanol to oil > reaction time > the amount of catalyst. Results show that the amount of catalyst and reaction time are reduced under ultrasound-assisted condition, and the optimum preparation conditions are: 20min of reaction time, 28KHz of the ultrasonic frequency, molar ratio of methanol to oil 9:1 and 2% catalyst. Under above conditions, the yield of biodiesel reaches 95.21%.

Abstract: Introduced one ultrasonic ranging alarm device based on SN8P2501B microcomputer, it mainly included ultrasonic emission circuit, receiving circuit, keyboard, alarm circuit and the software. Compared with the traditional ranging methods, the system used 555 time-base circuit to produce ultrasonic, and designed a temperature compensation circuit to eliminate effect of sound velocity produced by the environment temperature. The practical application results show that the ranging system is stable , reliable and highly accurate, so the technology and methods adopted in the system are highly practical and worthy of being used abroad.

Abstract: In this paper nanoSiO₂ particles were prepared with the surface grafted fluorine coupling agents and double bond by using surface modification technology. Dispersion effect of nanoSiO₂ particles were studied in different solvents ultrasound cavitation. Test results showed in infrared spectroscopy, TEM and laser particle size distribution analyzer that both F8261 and KH-570 have been grafted onto the surface of nanoSiO₂ , particle size and distribution of nanoSiO₂ after modified by the two coupling agent became smaller and more narrow; Tg-DSC analysis showed that when the amount of of the coupling agent is up to 10%, fluorine coupling agent and double bond grafted onto surface of nanoSiO₂ particles reach the saturation.