scholarly journals Research on the Processing Method of Acoustic Focusing Cavities Based on the Temperature Gradient

2021 ◽  
Vol 11 (12) ◽  
pp. 5737
Author(s):  
Liqun Wu ◽  
Yafei Fan ◽  
Hongcheng Wang ◽  
Linan Zhang ◽  
Yizheng Sheng ◽  
...  

Aiming at the key factors affecting the quality and efficiency of high-energy in-beam machining, this paper studies the broadband acoustic focusing effect based on a discrete temperature gradient. Firstly, the basic theory and mathematical model of temperature-controlled acoustic focusing are established. Secondly, the acoustic focusing effect is achieved by combining the design of metasurfaces and discrete temperature. Then, the acoustic pressure and intensity distribution of acoustic focusing under a discrete temperature gradient are simulated and experimentally studied. The results show that the phase delay of transmission and reflection of acoustic wave covers the 2π interval by changing the temperature in different transmission units, which provides a theoretical basis for the processing of the acoustic focusing cavity.

2016 ◽  
Vol 65 (4) ◽  
pp. 044303
Author(s):  
Liu Chen ◽  
Sun Hong-Xiang ◽  
Yuan Shou-Qi ◽  
Xia Jian-Ping

2021 ◽  
Author(s):  
Md. Mahmud

Biohydrogen production is most important for simultaneous energy generation. Hydrogen (H2) is considered as a suitable substitute source of energy because of its regenerative, carbon neutral and high energy yielding. However, to optimize key factors affecting hydrogen production from water hyacinth by heat treated anaerobic fermentation process. Biological methods is a potential option to meet the growing clean energy needs for hydrogen production. This paper was discussed about key factors affecting namely substrate concentration.


2014 ◽  
Vol 543-547 ◽  
pp. 3943-3946
Author(s):  
Gang Gou ◽  
Yong Liu ◽  
Zhong Yuan Lin

Aiming at the finishing of small hole of difficult-to-machine materials such as carbide, etc, this paper presented a new low speed electrical discharge grinding (EDG-LS) processing method, in which a machine tool accessory was equipped on WEDM-LS to realize the grinding process. Through the analysis of orthogonal test, the key factors affecting technological effect were discussed in the processing of EDG-LS, and the influence of average gap voltage, average gap current and workpiece speed on machining dimension and surface quality were elaborated respectively. It is of importantly theoretical and practical significance to seek better technology parameter in EDG-LS.


Author(s):  
Elena Evgenevna Mashyanova ◽  
Elena Aleksandrovna Smirnova

In modern conditions of development, financial security is an integral part of the overall security of the region and is formed on the basis of the functioning of the financial system. The complication of relationships between key segments of international financial markets, as well as the limited ability to accurately predict future trends in the development of the global financial system, lead to a gradual increase in the risks that accompany the activities of economic entities, and an increase in the number and scale of internal and external threats that have a negative impact on the financial security of the state. This formulation of the issue requires generalization of approaches to determining the financial security of the region in order to further formalize this issue and determine the key factors affecting it. The article considers the types of financial security, as well as certain areas of ensuring the financial security of the region and their priority. In work the assessment of the level of socio-economic development of the region with a view to ensuring financial security on the basis of which offers the main activities and priority areas of implementation of the investment policy that will ensure financial security of the Republic of Crimea.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.


Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.


2021 ◽  
Vol 13 (4) ◽  
pp. 1962
Author(s):  
Timo Liljamo ◽  
Heikki Liimatainen ◽  
Markus Pöllänen ◽  
Riku Viri

Car ownership is one of the key factors affecting travel behaviour and thus also essential in terms of sustainable mobility. This study examines car ownership and how people’s willingness to own a car may change in the future, when considering the effects of public transport, Mobility as a Service (MaaS) and automated vehicles (AVs). Results of two citizen surveys conducted with representative samples (NAV-survey = 2036; NMaaS-survey = 1176) of Finns aged 18–64 are presented. The results show that 39% of respondents would not want or need to own a car if public transport connections were good enough, 58% if the described mobility service was available and 65% if all vehicles in traffic were automated. Hence, car ownership can decrease as a result of the implementation of AVs and MaaS, and higher public transport quality of service. Current mobility behaviour has a strong correlation to car ownership, as respondents who use public transport frequently feel less of a will or need to own a car than others. Generally, women and younger people feel less of a will or need to own a car, but factors such as educational level and residential location seem to have a relatively low effect.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 474
Author(s):  
Huaqiao Liu ◽  
Yiren Pan ◽  
Huiguang Bian ◽  
Chuansheng Wang

In this study, the two key factors affecting the thermal performance of the insert rubber and stress distribution on the tire sidewall were analyzed extensively through various performance tests and simulations to promote the development of run-flat tires. Four compounds and two structures of insert rubber were designed to investigate the effects of heat accumulation and stress distribution on durability testing at zero pressure. It was concluded that the rigidity and tensile strength of the compound were negatively correlated with temperature. The deformation was a key factor that affects energy loss, which could not be judged solely by the loss factor. The stress distribution, however, should be considered in order to avoid early damage of the tire caused by stress concentration. On the whole, the careful balance of mechanical strength, energy loss, and structural rigidity was the key to the optimal development of run-flat tires. More importantly, the successful implementation of the simulations in the study provided important and useful guidance for run-flat tire development.


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