scholarly journals Design and simulation analysis of vacuum fish suction pump

2021 ◽  
Vol 2113 (1) ◽  
pp. 012009
Author(s):  
Ziyang Ding ◽  
Lingfeng Xu ◽  
Ming Gao ◽  
Guoqing Wang

Abstract Most of Chinese aquacultural products rely on artificial nets to catch in 2020. Fish suction pump can replace artificial net, is an important mechanical equipment of fish breeding industry. The development of fish suction pump is relatively backward and the level of automation is still to be improved, which is not conducive to the large-scale and rapid development of aquaculture in various countries. This paper designs a single tank vacuum suction fish pump, the suction fish pump mainly uses the tank and the air pressure difference, through the automatic control system on the suction fish pump and each stage of the control, relying on the gravity of the mixture of fish and water to release fish. In this paper, fluent was used to conduct simulation analysis on the flow diagram of fish-water mixture inhaled at work, and the flow diagram and velocity vector diagram of the internal flow field were obtained. The results show that the vacuum fish suction pump can effectively reduce the fish collision damage. The vacuum fish suction pump designed in this paper can effectively complete the fishing work of cultured fish, with the characteristics of high efficiency and low damage, which can provide theoretical reference for the design of vacuum fish suction pump in the future.

2017 ◽  
Vol 15 (02) ◽  
pp. 1750084 ◽  
Author(s):  
Yanju Ji ◽  
Tingzhe Huang ◽  
Wanyu Huang ◽  
Liangliang Rong

As an important supplement and development of traditional methods, the meshfree method has received a great deal of attention in the field of engineering calculation, and has been successfully used to solve many problems which traditional methods have difficulty in solving. However, the application of meshfree method is relatively less in the area of geophysics. In this paper, we apply the meshfree method to the numerical simulation of geophysical electromagnetic prospecting, taking the 2D magnetotelluric as an example and deduce the corresponding meshfree radial point interpolation method (RPIM) equivalent linear equations in detail. The high-efficiency and accurate solutions of large-scale sparse linear equations are solved by the quasi-minimal residual method based on Krylov subspace. The optimal values of the shape parameters are given by numerical experiments. The correctness of the meshfree method is verified by a layered model. The root mean square error of the calculation results is no more than 0.35%, its accuracy is superior to the finite element method. We also compare the meshfree solution with FEM solution by calculating an inclined vein body model, and the calculation results are in good agreement. A continuously changing fault model and undulating terrain model which traditional methods have difficulty in simulating are respectively calculated, the sectional profiles of the apparent resistivity accurately reflect the trend of the anomalies. The meshfree method does not require the complicated mesh generation, and the physical parameters are loaded at a series of points, thus it is especially suitable for the calculation of the complex geological models. With the rapid development of computational science, the meshfree techniques will certainly become a new robust numerical simulation method in geophysical electromagnetic prospecting.


2014 ◽  
Vol 953-954 ◽  
pp. 61-65
Author(s):  
Jing Chao Zhang ◽  
Zheng Gang Wang ◽  
Feng Zhen Zhou ◽  
Ning Xi Song ◽  
Qian Wang

In recent years, with the gradual depletion of traditional energy, as renewable energy representatives, new energy has developed rapidly. We know that distributed photovoltaic power generation with clean, pollution-free, easy installation, and therefore has been rapid development. However, the large number of distributed photovoltaic power generation connected to the distribution network would have a negative impact on the grid with a safe and reliable operation because of its randomness and volatility intrinsic properties. In this paper, in terms of power flow, voltage distribution, load characteristics, power quality, system protection and reliability departure, through MATLAB simulation analysis, the distribution network transformation strategies of primary and secondary devices has been proposed. It laid an important foundation for renewable energy development and the Third Industrial Revolution.


2020 ◽  
Vol 22 (1) ◽  
pp. 35-45
Author(s):  
Dan Mei ◽  
Junjie Shi ◽  
Yuzheng Zhu ◽  
Xuemei Xu ◽  
Futang Xing ◽  
...  

AbstractSpray Drying Absorber (SDA) has been widely used for large-scale desulfurization. However, it also has some limitations. For example, the liquid absorbent easily causes scaling, which impedes the contact between the serous fluid and the flue gas and reduces the chemical reaction rate and desulfurization efficiency. This paper establishes the mathematical and physical model of gas and liquid two-phase flow and droplet evaporation and heat transfer in rotary spray desulfurization tower. To study the accumulation and distribution of chemical reaction precipitates in the desulfurization tower and analyze the removal efficiency of sulfur dioxide (SO2) in different atomization diameters, this paper establishes a simulation model concerning the coupling of desulfurization reaction and flow field calculation based on the absorption and reaction mechanism of SO2. Baffle in different widths are set to optimize the internal flow field and balance the distribution of flue gas. By setting baffles of different widths to optimize the flow field in the tower and changing the distribution of flue gas, this model reduces the scaling while ensuring the desulfurization efficiency. The results of the simulation experiment have verified that the droplet with a diameter of 50 μm is the optimal option, which can effectively remove the scaling and ensure that the desulfurizing tower runs in high efficiency and stability. When the width of baffles is 2250 mm, the efficiency of desulfurization exceeds 95%, and the amount of scaling on the desulfurization tower main wall is controlled at the minimum level, which is the optimal option for production.


2020 ◽  
Vol 16 (9) ◽  
pp. 155014772095829
Author(s):  
Changsong Yang ◽  
Yueling Liu ◽  
Xiaoling Tao

With the rapid development of cloud computing, an increasing number of data owners are willing to employ cloud storage service. In cloud storage, the resource-constraint data owners can outsource their large-scale data to the remote cloud server, by which they can greatly reduce local storage overhead and computation cost. Despite plenty of attractive advantages, cloud storage inevitably suffers from some new security challenges due to the separation of outsourced data ownership and its management, such as secure data insertion and deletion. The cloud server may maliciously reserve some data copies and return a wrong deletion result to cheat the data owner. Moreover, it is very difficult for the data owner to securely insert some new data blocks into the outsourced data set. To solve the above two problems, we adopt the primitive of Merkle sum hash tree to design a novel publicly verifiable cloud data deletion scheme, which can also simultaneously achieve provable data storage and dynamic data insertion. Moreover, an interesting property of our proposed scheme is that it can satisfy private and public verifiability without requiring any trusted third party. Furthermore, we formally prove that our proposed scheme not only can achieve the desired security properties, but also can realize the high efficiency and practicality.


Author(s):  
Kesai Ouyang ◽  
Wei Xiong ◽  
Guoqiang Liu ◽  
Qingbo He

With the rapid development of transportation, wayside condition monitoring and fault diagnosis of key acoustic sources has attracted considerable attentions because of low cost and high efficiency. However, serious Doppler distortion exists in the wayside acquired signals when the monitored moving source passes by the system at high velocity, which makes it difficult for condition monitoring and fault diagnosis. This paper presents a novel method involving short-time sparse singular value decomposition to eliminate Doppler distortion in the wayside acquired signals based on a microphone array. The procedure of the proposed short-time sparse singular value decomposition is performed as follows. First, the Doppler distorted array signals are decomposed into a series of array segments by a sliding window with a proper window length. Afterwards, the time-varying direction of arrival of the corresponding array segments is acquired by individual sparse singular value decomposition. Then the fitting time-varying directions of arrival and time-domain interpolation resampling are employed to correct the Doppler distorted signals for recovering the objective characteristic frequency. Simulation analysis has validated that under heavy background noise situation, better localization accuracy and effectiveness of the proposed short-time sparse singular value decomposition could be achieved in comparison with other strategies like short-time multiple signal classification. Besides, the real data cases have verified the effectiveness of the proposed method, which shows great potential applications in wayside condition monitoring and fault diagnosis system for moving vehicles, trains, planes, etc.


2019 ◽  
Vol 35 (24) ◽  
pp. 5191-5198 ◽  
Author(s):  
Xiangxiang Zeng ◽  
Siyi Zhu ◽  
Xiangrong Liu ◽  
Yadi Zhou ◽  
Ruth Nussinov ◽  
...  

Abstract Motivation Traditional drug discovery and development are often time-consuming and high risk. Repurposing/repositioning of approved drugs offers a relatively low-cost and high-efficiency approach toward rapid development of efficacious treatments. The emergence of large-scale, heterogeneous biological networks has offered unprecedented opportunities for developing in silico drug repositioning approaches. However, capturing highly non-linear, heterogeneous network structures by most existing approaches for drug repositioning has been challenging. Results In this study, we developed a network-based deep-learning approach, termed deepDR, for in silico drug repurposing by integrating 10 networks: one drug–disease, one drug-side-effect, one drug–target and seven drug–drug networks. Specifically, deepDR learns high-level features of drugs from the heterogeneous networks by a multi-modal deep autoencoder. Then the learned low-dimensional representation of drugs together with clinically reported drug–disease pairs are encoded and decoded collectively via a variational autoencoder to infer candidates for approved drugs for which they were not originally approved. We found that deepDR revealed high performance [the area under receiver operating characteristic curve (AUROC) = 0.908], outperforming conventional network-based or machine learning-based approaches. Importantly, deepDR-predicted drug–disease associations were validated by the ClinicalTrials.gov database (AUROC = 0.826) and we showcased several novel deepDR-predicted approved drugs for Alzheimer’s disease (e.g. risperidone and aripiprazole) and Parkinson’s disease (e.g. methylphenidate and pergolide). Availability and implementation Source code and data can be downloaded from https://github.com/ChengF-Lab/deepDR Supplementary information Supplementary data are available online at Bioinformatics.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Danjuan Liu ◽  
Wei He

Abstract The paper derives the current-voltage relationship in the semiconductor circuit breaker based on the equation of fluid mechanics which has application for safe and water access. Then, the paper proposes a Newton iterative method based on the finite element analysis method to solve the nonlinear algebraic equation relationship in the semiconductor circuit breaker. At the same time, the paper constructed a coupled numerical model based on the hydrodynamic equations and applied it to the pulse current prediction. Experiments have proved that the algorithm can realize large-scale open-circuit switching current forecast, and the algorithm has high efficiency and accuracy.


2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>


2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>


2020 ◽  
Vol 60 (1) ◽  
pp. 159-168
Author(s):  
V. V. Antonenko ◽  
A. V. Zubkov ◽  
S. N. Kruchina

Data were obtained on the basis of the results of research carried out on the territory of the educational and experimental farm of the Timiryazev State Agrarian University, in Moscow during 2018-2019. As a result of the surveys, the most dangerous diseases and pests of pome crops on the territory of this farm were established. The most resistant apple and pear varieties to major diseases have been identified. Peculiarities of development of alternariosis on pear are described, the harmfulness of the disease on pear and apple seedlings is noted. A possible role in the transfer of alternariosis infection from garden-protective plantations and weed vegetation to fruit trees was noted. A possible role has been established in the transport of septoriosis, powdery dew infection from dicotyledonous weeds plants. The peculiarities of the spread of infection under the influence of wind direction are noted. The results and peculiarities of the application of various methods of scaring birds in the orchard are presented. As a result of route surveys the most harmful weed plants have been identified. The possibility of using herbicides of different mechanism of action in fruit gardens for weed control has been studied. High efficiency and relative safety of application of herbicides of contact action in nursery fields, operational orchards and for control of piglets on fruit trees are shown. Recommendations are given for the use of soil and systemic herbicides of soil in seedlings beds, the first and second fields of the nursery, as well as in the process of production of large-scale planting material and operational orchards of fruit crops. The safety of the herbicides in question is established when used in accordance with the recommended methods of use.


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