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1

An empirical study on emissions trading influence for the enterprise environmental responsibility

Zhao Jing-Xuan

Ecological Chemistry and Engineering. S

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2023

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Vol. 30, nr 2

259--266

EN

The primary objective of this paper is to address the inherent biases in the calculation of carbon emissions trading (CET) and foster the development of green innovation. By employing panel data from carbon emission trading pilots, the spatial Durbin model (SDID) is applied to assess the impact of CET on corporate environmental responsibility. By integrating CET and corporate environmental responsibility within a unified framework, this paper presents a novel analysis of the influence of environmental regulations on corporate environmental responsibility at the micro-level. Additionally, this study examines the spatial spillover effect of CET, thereby rectifying estimation biases. The model validation results indicate statistical significance below the 1 % level. The findings of this research reveal that it analyses the specific channels through which CET influences corporate environmental responsibility, providing insights that address the limitations of previous studies in mechanism analysis.

2

Monitoring the performance of a ship’s main engine based on big data technology

Liang Meng, Chen Mingzhi

Polish Maritime Research

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2022

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nr 3

128--140

EN

Under the recent background of ‘Green Shipping’ and rising fuel prices, it is very important to reduce the fuel consumption rate of ships, which is directly affected by the performance of the main engine. A reasonable maintenance schedule can optimise the performance of the main engine. However, a traditional maintenance schedule is based on the navigation distance and time, ignoring many other factors, such as a harsh working environments and frequently changing operating conditions, which will lead to faster performance degradation. In this study, a real-time evaluation method combing big data of ship energy efficiency with physics-based analysis is proposed to judge the degradation of main engine performance and assist in determining the maintenance schedule. Firstly, based on the developed ship energy efficiency big data platform, the distribution statistics and comparison of different operating states are carried out. Gaussian mixture model (GMM) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) are used to cluster the data and the high-density data areas are obtained as the analysis points. Then, the data of the analysis points are polynomial fitted, by the least square method, to obtain the propulsion characteristics curves, load characteristic curves, and speed characteristic curves, which can be used to observe the performance degradation of the main engine. The results show that this method can effectively monitor the degradation degree of the main engine performance, and is of great significance to fuel efficiency improvements and greenhouse gas (GHG) emissions reduction.

3

Effect and mechanism analysis of hydroxylated nano‑boron nitride on workability and multi‑scale mechanical properties of cement paste

Liu Jianglin, Li Yue, Jin Caiyun, Lin Hui, Li Hongwen

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e122

EN

Nano-boron nitride (h-BN) has excellent physical and mechanical properties. Due to its stable chemical performance, the improvement effect on the properties of cement-based materials was limited. Therefore, the chemical modification method was used to prepare functional h-BN to improve its application potential in cement-based materials in this paper. The hydroxylated nano-boron nitride (h-BN-OH) was prepared by modified pristine h-BN with saturated sodium hydroxide (NaOH). The effects of h-BN-OH after ultrasonic dispersion for 10 min, 20 min, 30 min and 40 min on the setting time, fluidity, resistivity, mascroscopic strength and microscopic Young’s modulus of hydration products of ordinary Portland cement were investigated. Fourier transform infrared spectroscopy (FTIR) test results showed that h-BN-OH had obvious hydroxyl infrared characteristic peaks. After adding h-BN-OH into cement paste, the initial and final setting time of cement paste was shortened 6.44-15.34% and 5.05-13.00%, respectively; the fluidity was reduced 9.86-22.79%, and the resistivity was increased 7.14-25.96%. Meanwhile, the compressive strength of cement paste and the microscopic Young’s modulus of hydration products were significantly improved 10.82-40.85% and 9.90-31.01%, respectively. The main reasons were as follows: (1) The dispersion effect and stability of h-BN-OH in cement pore solution were better than that of pristine h-BN, and the hydroxyl group grafted on the h-BN-OH provided nucleation sites for the growth of calcium-silicate hydrate (C-S-H) gel. (2) The hydroxyl groups grafted on the h-BN-OH can absorb Ca2+, resulting the polymerization degree (nc) and medium chain length (MCL) of C-S-H gel increased. The formation of C-S-H gel network structure was accelerated by the increasing proportion of Q3. (3) The pore structure of cement hydration products was significantly optimized.

4

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.

5

Effect of multi-walled carbon nanotubes on the damping property of cement mortar and mechanism analysis

Li Yue, Li Hongwen, Jin Caiyun

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

289--302

EN

The effect of the type and content of multi-wall carbon nanotubes (MWCNTs) on the damping performance of cement mortar is studied in this paper. The pristine MWCNTs (P-CNT) and the functionalized MWCNTs (F-CNT) grafted with COOH were used in the experiment. The content of MWCNTs was 0.05wt% and 0.1wt% of cement. The flexural/compressive strength and loss factor of CNT-mortar composites were measured. The experimental results show that MWCNTs can significantly enhance the flexural strength and loss factor, and the values increased with the increase of CNTs content. The effect F-CNT was better than P-CNT when the MWCNTs content was the same due to the presence of COOH. The mechanism of MWCNTs reinforced mortar damping performance was analyzed by a variety of micro test techniques. The test results of X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and thermogravimetry showed that MWCNTs did not change the compositions of mortar, but improved the polymerization degree of gel and the degree of hydration of cement. The results of mercury intrusion porosimetry, N2 adsorption and backscattered scanning electron microscopy showed that MWCNTs effectively reduced the porosity and interfacial transition zone thickness of mortar. Transmission electron microscope results showed that the energy dissipation capacity of mortar is increased due to the bridging effect of MWCNTs.

6

Influence of Material Damping on Dynamics of Slider-Crank Mechanism

Hać M.

Machine Dynamics Research

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2012

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Vol. 36, No. 2

16-25

EN

In this paper the dynamic analysis of a slider-crank mechanism is presented. It is taken into account the flexibility of links by applying finite element method with beam-type planar finite elements. The influence of material damping on dynamic behaviour of slider- crank mechanism is investigated. Mechanism is driven by variant torque applied to the crank and vibrational transient response is analysed. The midpoint deflection of the connecting rod as well as the displacement and velocity of slider are shown for the cases when Rayleigh proportional damping model is taken into account and for undamped vibration of links.

7

Positioning of Manipulator's Tip with Regard to Accuracy of Link Machining

Hać M., Kiszka K.

Machine Dynamics Research

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2011

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Vol. 35, No. 2

108-120

EN

In this paper the kinematic and dynamic analysis of planar two-link flexible manipulator is studied with the machining tolerance of links taken into account. The influence of different cross-section area within the assumed tolerance on the dynamic behaviour of manipulator's tip is investigated. For vibration analysis of links the finite element method is used with Bernoulli-Euler beam elements. The results of analysis show that the changes in the cross-sectional shape of manipulator's links, within the assumed tolerance of machining, can be quite significant and can influence the positioning accuracy of themanipulator. In order to obtain the exact trajectory of manipulator's tip the adaptive control system should be applied.