Wyniki wyszukiwania - BazTech

1

Study on the Unexpected Loss Measurement of Environmental Pollution from Energy Consumption Waste Emissions in Industrial Parks Based on Extreme Value VaR Model

Sun Tao, Shi Peishi, Zhao Yu, Han Xiuyan

Rocznik Ochrona Środowiska

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2023

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Tom 25

399--412

EN

The waste emission of energy consumption in industrial parks causes huge expected environmental pollution loss but also causes serious environmental pollution losses in the form of accidents. To explore the measurement method of the environmental pollution losses of waste emissions from energy consumption in industrial parks and the effective way of its application, based on the literature review and theoretical analysis, extreme value theory and VaR theory was introduced to construct the extreme value VaR model for the measurement of environmental pollution losses of wastes emission from energy consumption in industrial parks. The maximum likelihood estimation method was used to estimate the parameters of the measurement model. Then, the application test was carried out with the case data of waste emission from energy consumption in Nanjing MV industrial park, which verifies the effectiveness of the research method and its application.

2

Numerical analysis of the effects of canal wall-up and canal wall-down mastoidectomy on the sound transmission characteristics of human ears

Liu Peihan, Liu Wen, Zhao Yu, Yan Shanshan, Jiang Wen, Liu Houguang, Wan Jin

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 2

133--145

EN

The aim of this work was to study the effect of canal wall-up (CWU) and canal wall-down (CWD) and mastoid obliteration in conjunction with CWD (CWD-MO) mastoidectomy on the sound transmission characteristics of the human ear. Methods: Three mastoidectomy surgical methods, CWU, CWD and CWD-MO, were simulated on the freshly dissected cadaver heads. Then, the finite element (FE) models corresponding to these surgical methods were established by micro-computed tomography (Micro-CT) and reverse engineering technology, and the accuracy of the models was verified. Finally, the FE Models were used to analyze the effects of different surgical methods on the sound transmission characteristics of the human ear. Results: For CWU, since the integrity of the outer wall of the ear canal is ensured, the sound pressure (SP) gain of the ear canal and the stapes footplate displacement (FPD) gain after this operation are close to normal values. For CWD, due to severe damage to the outer wall of the ear canal, a negative gain of the ear canal SP occurs in the high-frequency range, and the resonance frequency is significantly reduced. For CWD-MO, the frequency range of SP negative gain in the ear canal is reduced due to the addition of fillers in the ear canal to reduce the degree of damage, and the resonance frequency is increased compared to CWD. Conclusions: The impact of three types of mastoidectomy, including CWU, CWD, and CWDMO, on the sound transmission characteristics of the human ear after surgery is relatively small.

3

Effect of N-carboxybutyl chitosan on the flotation separation of apatite from dolomite

Rao Yubei, Liu Shanhui, Gao Jiewang, Zhao Yu, Saffari Pooya, Kang Shuo, Liu Zuwen

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 4

27--35

EN

With high-grade apatite resources exhausted and economic development, enhancing the apatite quality from calcium gangue such as dolomite has a great significance for production. However, it is difficult to separate apatite from dolomite effectively due to the similar surface properties. In this study, the N-carboxybutyl chitosan (CBC) was tested as a potential selective depressant to separate apatite from dolomite in the sodium oleate (NaOL). Flotation results of single mineral and artificially mixed mineral confirmed the selective depression effect of CBC. The depression mechanism of CBC was investigated using wettability analysis, Fourier Transform Infrared (FTIR), and X-ray Photoelectron Spectroscopy (XPS) analyses. The results indicated that the CBC adsorption quantity and intensity on the dolomite surface more than that on the apatite surface, which was due to CBC absorbed on apatite surface by hydrogen bonding, while absorbed on dolomite surface mainly through chemical chelating between Ca on the mineral surface and -COO- on the depressant. These adsorption differences led to the flotation separation of the two minerals.

4

Research on the embossment phenomenon of disc grinding by workpiece's removal rate

Sun Cong, Xiu Shichao, Li Qingliang, Wang Jingyu, Zhao Yu

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 3

739--755

EN

The disc grinding has become a widely used technology in the precision-manufacturing process for plate stainless steel. However, embossment phenomenon occurs on the ground workpiece's surface. Moreover, the workpiece's removal rate can be applied to measure the embossment. In most studies, the researches on the disc grinding technology mainly focus on the trajectory distributions, which might be not appropriate enough to capture the workpiece's removal rate. To this end, this paper has presented a multiple grits-discretized (MGD) model on the workpiece's removal rate to identify the formation mechanism of the embossment phenomenon. Meanwhile, the current model is established based on the grits' distributions, the grits' size and the kinematic multiple grits' trajectory. The theoretical prediction for the distribution of workpiece's removal rate shows a reasonable agreement with the experimental validation. It shows that the removal rate is non-uniformly distributed on the workpiece's surface, which results in the workpiece's embossment. Furthermore, the workpiece's removal rate is greatly affected by the speed ratio. Therefore, the proposed model is not only anticipated to be meaningful for improving the uniformity of the machined workpiece by adjusting the speed ratio, but also expected to be useful for enhancing the understanding on the disc grinding enterprises.

5

Influence of middle ear disorder in round-window stimulation using a finite element human ear model

Zhou Kai, Liu Houguang, Yang Jianhua, Zhao Yu, Rao Zhushi, Yang Shanguo

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 1

3--12

EN

The aim of this work was to study the effect of middle ear disorder on round window (RW) stimulation, so as to provide references for the optimal design of RW stimulation type middle ear implants (MEIs). Methods: A human ear finite-element model was built by reverse engineering technique based on micro-computed tomography scanning images of human temporal bone, and was validated by three sets of comparisons with experimental data. Then, based on this model, typical disorders in otosclerosis and otitis media were simulated. Finally, their influences on the RW stimulation were analyzed by comparison of the displacements of the basilar membrane. Results: For the otosclerosis, the stapedial abnormal bone growth severely deteriorated the equivalent sound pressure of the RW stimulation at higher frequencies, while the hardening of ligaments and tendons prominently decreased the RW stimulation at lower frequencies. Besides, among the hardening of the studied tissues, the influence of the stapedial annular ligament’s hardening was much more significant. For the otitis media, the round window membrane (RWM)’s thickening mainly decreased the RW stimulation’s performance at lower frequencies. When the elastic modulus’ reduction of the RWM was considered at the same time especially for the acute otitis media, it would raise the lower-frequency performance of the RW stimulation. Conclusions: The influence of the middle ear disorder on the RW stimulation is considerable and variable, it should be considered during the design of the RW stimulation type MEIs.