Seung Kyo Lee, Dongil Chu, Eun Kyu Kim^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 93-93, 2019, DOI:10.32604/icces.2019.04995

Abstract We studied on a liquid exfoliation technique for the robust production of transition metal dichalcogenides (TMDC) thin films, because this technique has advantages for residue-free, large-scale, and low-cost fabrication. During the process of liquid exfoliation, a mixture of DI water and ethanol was used to obtain higher concentrations of TMDC flakes in the solution compared to that in water-based solution. The film thicknesses were controlled by a two-step centrifuge process to analyze the influence on the photovoltaic properties with gold/TMDC/silicon geometry. Based on ultraviolet photoelectron spectroscopy measurement results, the energy band diagram of the devices… More >

Guiping Liu^*, Sheng Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 92-92, 2019, DOI:10.32604/icces.2019.05523

Abstract In engineering multi-objective optimization of structures, the parameters involved in the problems are usually given deterministic values. However, due to the presence of manufacturing and measurement errors, uncertainty inevitably exists in the geometrical properties of the structure, the material properties, the boundary conditions, etc. For uncertain problems, the interval optimization methods are widely used. They describe the uncertainty by intervals which only need to find the upper and lower bounds of the uncertain parameters instead of constructing the exact probability distribution function. However, in multi-objective optimization problems, if considered all the upper and lower bounds… More >

Bingyu Ni, Chao Jiang^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 91-91, 2019, DOI:10.32604/icces.2019.05517

Abstract Uncertain parameters with inherent spatial variability are commonly encountered in engineering. These include material properties of the heterogeneous media such as concrete or porous rock, external loads such as wind or snow loads applied on structures, etc. This type of uncertain parameters is traditionally quantified by the random field model, while the large amount of information required in construction of the precise probability distribution functions is often difficult to obtain for many practical engineering problems. The authors propose an interval field model to represent the spatial uncertainties with insufficient information, in which the variation of… More >

Hideo Matsufuru^1,*, Kohsuke Sumiyoshi²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 90-90, 2019, DOI:10.32604/icces.2019.05390

Abstract The core collapse supernovae are one of key phenomena to understand the history of the Universe and the origin of heavy elements. To understand their explosion mechanism, large scale numerical simulations are essential that require to solve a multi-physics system described by coupled equations of hydrodynamics and neutrino-radiation transfer in multidimensions. Since the neutrino transfer is governed by the Boltzmann equation in six-dimensional space, necessary computational resource rapidly increases as the number of grids in simulations grows. So far numerical studies have been performed mostly on massively parallel computers and only a few studies have… More >

Ye Chen, Yonghai Gao, Guizhen Xin, Wang Yao, Dongzhi Gao, Litao Chen, Baojiang Sun^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 88-89, 2019, DOI:10.32604/icces.2019.05522

Abstract Natural gas hydrate is regarded as a kind of potential alternative energy resource and attracts the attention all over the world. Geological surveys have found that most natural gas hydrates are buried at the bottom of the sea. Several development methods, such as depressurization, thermal stimulation and inhibitor injection are proposed gradually on the basis of hydrate special properties, obtaining certain trial-produce performance. It is of great significance to learn the flow rules underground for production safety guarantee and efficiency improvement. However, the special phase transition of hydrate between solid and fluid accompanied by energy… More >

Hongwei Yang^1,*, Jun Li¹, Gonghui Liu^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 87-87, 2019, DOI:10.32604/icces.2019.05080

Abstract When gas kick occurs in deepwater drilling, solid hydrate particles are easily formed during the gas bubble rising in the wellbore under low temperature and high pressure conditions, which not only affects the flow characteristics of the mud, but also may lead to wellbore blockage and increase the difficulty and risk of well control treatment.
In this paper, based on water-in-oil drilling fluid, a comprehensive model of hydrate shell growing on droplet surface is established, including an inward growth model and an outward growth model of hydrate shell. The main factors considered in this model are:… More >

Na Wei^1,*, Jinzhou Zhao¹, Wantong Sun¹, Shouwei Zhou¹, Liehui Zhang¹, Qingping Li², Haitao Li¹, Qiang Fu^1,2, Xin Lv², Lijun Zheng²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 84-86, 2019, DOI:10.32604/icces.2019.04533

Abstract Currently, marine natural gas hydrate has attracted people’s attention due to its huge amount of resources. As a creative way to securely and efficiently exploit metastable hydrate reservoir which is in shallow subsurface of sea floor and with weak cementing, the method of solid fluidization exploitation is to excavate and crush the marine natural gas hydrate reservoir, transport the hydrate to the sea surface platform through the airtight pipeline, and finally the methane gas is obtained after post-processing.
In the process that the hydrate solid particles are transported up, as the temperature rises and the pressure… More >

Lin Jiang^1,*, Na Wei^1,*, Jinzhou Zhao¹, Shouwei Zhou^1,2, Liehui Zhang¹, Qingping Li³, Guorong Wang¹, Jun Zhao¹, Kaisong Wu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 81-83, 2019, DOI:10.32604/icces.2019.04515

Abstract With huge reserves, marine natural gas hydrate is one of the most potential unconventional alternative energy sources after shale gas, coalbed methane and tight gas. The research and pilot engineering of natural gas hydrate exploitation technology mainly adopts the depressurization method at home and abroad, all of which refer to the exploitation technology of conventional oil and gas.
While using the depressurization method to exploit the non-diagenetic gas hydrate, the undersea hydrate decomposes in situ, partly flows to the bottom of the well, and escapes into the seawater in large quantities, and the hydrate will face… More >

Wei Cai^*, Hua Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 80-80, 2019, DOI:10.32604/icces.2019.05672

Abstract Recent decades have witnessed a fast growing research on the theory of wave propagation in granular materials because of its important applications of frequency dependent attenuation. Fractional calculus has been recognized as an efficient tool to model such kind of phenomena. This study firstly presented a survey of the frequency-dependent attenuated fractional wave models. To have a better understanding of the wave propagation in layered materials, the variable-order fractional wave equation is subsequently proposed on the basis of the corresponding viscoelastic constitutive equation. Numerical simulations compared with traditional models are presented by the implicit finite More >

Jichang Wang, Xiaoming Guo^*, Xiaoxiao Sun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 79-79, 2019, DOI:10.32604/icces.2019.05248

Abstract Cement mortar is an important component of many composite materials and one of the most widely used materials in engineering construction. At microscopic level, cement mortar can be regarded as a multiphase material composed of fine aggregates, cement paste, and a great many of initial defects, the form of which are micro-cracks and micro-voids. The macroscopic properties of cement mortar will be influenced by mechanical properties of different constituents and complex internal structures. The microscopic model containing micro-voids is established by the method of secondary development. The process of cement mortar damage fracture is studied.… More >