bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical simulation of a heat exchanger using Al2O3 nanofluid and STES
Authors: Baran A I , Mateescu T , Luciu R S 
Published: September 2019

Abstract
The major energy crisis, predictable for the global economy, requires attentive research & development in order to grow energy performance, heat transfer and energy storage. It is a known fact that in the energy balance, the biggest share is in thermal energy and that justifies the continuous effort in the optimization of fossil fuel saving solutions and intense promotion of renewable energies. Use of the latter in heating and cooling systems as well as “waste heat” from different processes is consistent with the concept of sustainable development and results in reduction of conventional fuel consumption and emissions. Optimizing such a system can be made by replacing the usual storage material with phase changing materials and by using nanofluids as a secondary agent with the beneficial effect on heat transfer. In this paper we have studied a simplified multitubular heat exchanger, buried in the ground, having as a primary working fluid plain water and nanofluid, using Ansys. The nanofluid is composed of particles of A12O3 dispersed in water at a concentration of 1%. The study indicates an increase in convective heat transfer coefficient of nanofluid compared to water.
The effect of Stone Powder content of dolomite manufactured sand on the cement Hydration
Authors: Guo Jun-Hua , Li Gong-Zhou , Gao Chun-Yong 
Published: September 2019

Abstract
In this paper, the effects of different stone powder content (5%, 10%, 15%, 20%, 25%) of dolomite manufactured sand on the workability and mechanical properties of cement were studied. The influence of stone powder content on the hydration products and microstructure of cement were studied by XRD, SEM. The results show that the workability and mechanical properties of cement can be improved obviously when the content of stone powder is less than 10%, and the influence of stone powder on hydration products and Microstructure of cement is small.
Study on Properties of Binary Composite Cementitious Self-leveling Mortar
Authors: Dong W Y , Fang C Q , Hu R 
Published: September 2019

Abstract
The binary composite cementitious self-leveling mortar is an important development direction of modern building construction. At present, there are great differences in opinions on the mixing proportion of Portland cement and aluminate cement or sulphoaluminate cement in binary system and there are few literatures comparing the fluidity and strength of the two kinds of mortar. In this paper, the fluidity, flexural strength and compressive strength of the two kinds of mortar with different dosages were compared. The research results showed that the addition of aluminate cement and sulphoaluminate cement could reduce the initial fluidity and 20min fluidity of mortars, but the decreasing degree was different. The influence of different dosages of aluminate cement and sulphoaluminate cement on the flexural strength and compressive strength of mortars was obviously different. When the dosage of aluminate cement was 0-10%, the flexural strength and 1d compressive strength of mortar could be improved remarkably. When the dosage was higher than 10%, the strengths were obviously reduced, even lower than the strengths of Portland cement mortar. The flexural strength of the mortar increased with the increase of sulphoaluminate cement in the range of test dosages, but the 1d compressive strength had little difference. When the dosage was 10%-20%, the influences of the two kinds of cement on the 28d compressive strength of mortars were basically consistent and both could improve the 28d compressive strength of mortars.
Study on the effect of iron tailings manufactured sand powder content on cement Hydration
Authors: Guo Jun-Hua , Li Gong-Zhou , Gao Chun-Yong 
Published: September 2019

Abstract
In this paper, the effects of different stone powder content (5%, 10%, 15%, 20%, 25%) of iron tailings manufactured sand on the workability and mechanical properties of cement were studied. The results show that the strength of hardened paste can be improved by adding appropriate amount of stone powder. When the content of stone powder is 5%, The compressive strength reached 34.4MPa. The results of XRD show that the hydration products of cementitious materials mixed with stone powder are mainly ettringite, Ca(OH)2, hydro calcium, calcium silicate hydrate and quartz. The results of SEM show that proper amount of stone powder can effectively improve the porosity of composite cementitious materials, but the content of stone powder increases, the bond between stone powder and hydration products is not close enough, and the paste structure becomes loose.
Characterization of functionally graded concrete produced with fibres and recycled aggregates
Authors: Hu Tong , Chan Ricardo , Galobardes Isaac , Liu Xingzi , Moy Charles K.S. , Hao Jian Li , Krabbenhoft Kristian 
Published: September 2019

Abstract
Conventional reinforced concrete is widely used in the pavement construction despite its technical drawbacks, economic and environmental issues. To address these matters, the concept of functionally graded material (FGM) with materials that present changeable properties over its volume is adopted on concrete, generating functionally graded concrete (FGC). However, more studies are needed to understand how this material performs. In this study, six mixes of FGC concretes were produced to assess the effect of the recycled aggregate and different depths of the fiber reinforced layer on the flexural performance. Besides, the inductive method was performed to estimate the fiber content and distribution in the mixes. The outcomes of the study highlight the inductive method as a good tool to perform the quality control of the mixes and that FGC produced with recycled aggregates and fibers present great potential in terms of Serviceability Limit States (small deflection).
Heat and humidity performance of EPS and Rock wool board external thermal insulation system
Authors: Yang Z H , Guo P L , Chen X , Jiang W 
Published: September 2019

Abstract
A coupled heat and humidity transfer model of external thermal insulation wall is established, and the accuracy of the model is verified by the field test data. Taking Shanghai, a typical hot summer and cold winter area, as an example, this paper simulated and analysed the effects of different climatic conditions (winter and summer) and types of insulation board (rock wool and EPS) on the thermal and humidity properties of concrete-mortar-insulation-mortar external insulation wall. The results show that the temperature variation of the bonding mortar on the inside of the insulation board is much smaller than that on the outside of the insulation board due to the thermal insulation effect; the relative humidity of the bonding mortar layer in the external insulation system of rock wool can reach more than 80% within 7 days in summer, which has a high risk of falling off; and the relative humidity of the coating mortar layer can reach about 73% within 7 days in winter, which is likely to become mildewed; The resistance to moisture migration of rock wool is weaker than that of EPS.
Finite Element Analysis of PGM Process for Wafer Based Lens Array
Authors: Hu Yang , Zhou Jian , Li Mujun , Shen Lianguan 
Published: September 2019

Abstract
In order to study the PGM process for wafer based lens array, we established a 3D finite element model of glass wafer with lens array by using the submodel technique in ABAQUS. Then assessment criteria of the molded lens and influence of different PGM process parameters were investigated thoroughly. The obtained results show that during the molding stage, proper molding pressure can help the lens fill better and decrease the sag height deviation significantly. While during the annealing stage, holding pressure is essential for keeping the molded lens’ structure and position, but residual stress must be considered at the same time.
Study on the properties of PPS composite modified with Tungsten powder
Authors: Zhang Yi , Yang Weiwei , Zhuang Xiaohui , Liu Jiping , Han Jia 
Published: September 2019

Abstract
The tungsten powder (W) and polyphenylene sulfide (PPS) as the main raw material, through mixing, extrusion molding and extrusion molding method contrast, determines the extrusion method for the preparation of tungsten powder/PPS (W/PPS) composites, was studied by DSC, XRD and SEM after modification, the W powder for W/PPS material microstructure and the influence of thermal performance. W was mixed evenly in PPS, and the thermal decomposition temperature of PPS was increased.
Study on Application of Waste Polyethylene and SBS in Modified Asphalt
Authors: Peng Yang , Long Wu-Jian , Han Ning-Xu , Sui Li-Li , Wang Xue-Lian , Liu Yan-Hong 
Published: September 2019

Abstract
In this paper, modified asphalt was prepared by using waste polyethylene and SBS. Through the performance test of modified asphalt, it was found that waste PE (Polyethylene) and SBS (Styrene-Butadiene-Styrene) modified asphalt had good physical and mechanical properties. Through the asphalt mixture’s test, it was found that the waste polyethylene and SBS modified asphalt mixture had good high temperature stability, low temperature crack resistance and excellent fatigue performance.
First-principle and molecular dynamic calculation of concrete-filled steel tubular to introduce stainless steel technology
Authors: Guo Yaqin , Liang Duoqiang , Deng Yong , Zheng Xuemei 
Published: September 2019

Abstract
The concrete-filled steel tubular (CFST) structure offers numerous structural benefits, including high strength and fire resistances, favorable ductility and large energy absorption capacities. There is also no need for the use of shuttering during concrete construction; hence, the construction cost and time are reduced. These advantages have been widely exploited and have led to the extensive use of concrete-filled tubular structures in civil engineering structures. In the existing dozens of species types of stainless steel, some are suitable for concrete-filled steel tubular, some not. In this paper, the principles for selection of such types are studied, by both quantum mechanism and molecular dynamic method.
Evaluation of ionic liquid “greenness”-cytotoxicity of ionic liquids
Authors: Kong Q , Zheng S S , Liu T Q , Nie Y , Song K D 
Published: September 2019

Abstract
Ionic liquids have become a hot spot in research and application due to their own superiority. At the same time, the “risk” of ionic liquids has attracted more and more attention. The toxicity of ionic liquids varies according to the target. We have to obtain the toxicity data of ionic liquids on various organisms and cell lines, fill in the blanks of ionic liquid toxicity data and clarify the toxicity mechanism. Only in this way, can we lay the foundation for the design and synthesis of new ionic liquids that are truly non-toxic, environmentally friendly and meet functional requirements. In this experiment, 1-ethyl-3-imidazole diethyl phosphate ([Emim]DEP) was prepared by using 1-methylimidazole and triethyl phosphate as raw materials. The rat cranial anterior osteoblast cell line (MC3T3-E1) was used as the research object, using MTT method, fluorescent death-sense staining observation and flow cytometry to study the cytotoxicity of 1-allyl-3-methylimidazolium chloride ([Emim]DEP) type ionic liquid. This article aims to determine the median lethal concentration by the inhibition rate-concentration curve of [Emim]DEP type ionic liquid and measure cell survival index at this concentration.
Experimental study on electrical conductivity of carbon nanofiber reinforced concrete
Authors: Wang Tengjiao , Xu Jinyu , Bai Erlei , Chen Haowen , Liu Gaojie , Chang Sen 
Published: September 2019

Abstract
To study the effect of carbon nanofibers (CNFs) on the electrical conductivity of concrete, we used the four-electrode method to measure the resistance and resistivity of carbon nanofiber reinforced concrete (CNFRC) under different ages, different fiber content and different test voltages. The results show that the incorporation of CNFs into concrete can improve the electrical conductivity of concrete. The electrical resistance and electrical resistivity of CNFRC increase with the increase of concrete age, but the growth rate decreases gradually. The resistance and electrical resistivity of CNFRC decrease with the increase of carbon nanofiber content and the optimum dosage range is 0.1%-0.3%. The resistance and electrical resistivity of CNFRC decrease with the increase of test voltage, and when the test voltage is 1V~5V, the resistance and electrical resistivity decrease significantly.
Stability enhancement of flexible CZTSSe solar cells by using nanopore array substrate
Authors: Li Jinze , Hao Wenbin , Duan Jingjing , Xu Jie 
Published: September 2019

Abstract
Flexible CZTSSe solar cells were prepared on both thinned silicon substrate with and without nanopore array surface. The nanopore array structure could release thermal stress during the CZTSSe thin film preparation process, which improved the crystallization of CZTSSe thin film. The array structure could also absorb some bending stress during the bending test of CZTSSe solar cell, leading to obtaining a more reliable device. A flexible CZTSSe solar cell with only 14% efficiency loss after 3 times bending at 50mm radius was prepared by using nanopore array substrate.
Growth of Single-Layer MoS2 by Chemical Vapor Deposition on sapphire substrate
Authors: Yue Jiaojie , Jian Jiaying , Dong Pengfan , Luo Lei , Chang Fange 
Published: September 2019

Abstract
Single-layer molybdenum disulfide (MoS2) has attracted a significant amount of interest owing to its excellent electrical, optical, and mechanical properties. In this paper, we study that the effects of the distance between the molybdenum source and substrate as well as the substrate angle on the morphology, size, and structure of MoS2 films grown from molybdenum trioxide (MoO3) sulfide on sapphire substrates via the Chemical Vapor Deposition (CVD) by using Scanning electron microscopy (SEM), Raman spectra and Photoluminescence spectra (PL). On the results show that the distance between the substrate and molybdenum source affects the controllable growth of MoS2 films. When the substrate is too close to the molybdenum source, it results in increasing amount of non-reduced MoO3 particles which were deposited on the substrate. When the distance between the substrate and molybdenum source is too large, only a small amount of MoS2 is deposited on the substrate. High-quality MoS2 films can be prepared when the molybdenum source and substrate are 9.5 cm apart. When the substrate is inclined 30° and placed downstream of the molybdenum source with a distance of 9.5 cm, the size of the prepared single-layer MoS2 is approximately 100 μm, which is greater than that of MoS2 prepared on the horizontal face-up substrate.
Effect of Reaction Temperature on Silicon-Aluminum Alloy Prepared from Fly Ash
Authors: Bai Zhiling , Qin Bingke 
Published: September 2019

Abstract
The effect of carbothermal reduction of fly ash on the preparation of silicon and aluminium at different reaction temperatures was studied. XRD was used to analyze the phase of the reduction products at different reaction temperatures. The results showed that the products of carbothermal reduction fly ash included Al2O3, SiC, Al2SiO5, FeSiO3 and FeSi at 2073K. At 2123K, the products of carbon reduction fly ash were Al2O3, Al2SiO5, SiC, FeSi, Si and Al4.5FeSi. At 2173K, the main products of carbon reduction fly ash were Al2O3, Si, Al, SiC, FeSi and Al4.5FeSi. The diffraction peak intensity of silicon at 2173K was higher than that at 2123K, which indicated that increasing the reaction temperature was beneficial to the formation of silicon. Under the reaction conditions of 2223K and 2273K, the kinds of reduction products were the same, which were Al4.5FeSi, Si, Al, SiC and FeSi. The intensity of the diffraction peak of aluminium at 2273K was higher than that of aluminium at 2223K, which indicated that increasing the reaction temperature was beneficial to the formation of aluminium. In this experiment, with the increase of temperature, the degree of carbon reduction fly ash was more sufficient and 2273K was the optimum reaction temperature for preparing silicon-aluminium alloy from carbon reduction fly ash.
A new anti-freezing foam scrubbing agent technology research
Authors: Zhang Guangsheng , Duan Qiong , Cao Feng , Sun Ning 
Published: September 2019

Abstract
With the long delaying development and the higher pressure, the anniversary production of Yu-Lin Gas Field is reducing. Because of the lower temperature in the winter, the traditional foam scrubbing agent is not easy to foam that makes a poor drainage effect, lower developing and decreasing benefits. According to the common anti-freezer properties and parts of some development data, new anti-freezing foam scrubbing agent laboratory experimental study was put forward. Computed with the water production, when the new foam agent consumption is 200-400g/L, the roaming ration, foam stability and water carrying ability is greatly improved. When the foam agent consumption is 200g/L, the freezing point of foam scrubbing agent can reach to-10°C, and when 400g/L, it can reach to -25°C, which both satisfy the site temperature condition.
Progress in Preparation and Research of Hydrophilic Composite Nanofiltration Membrane
Authors: Yang Zhenhao , Zhang Liqing , Zhang Zhiqiang , Hu Jiyu 
Published: September 2019

Abstract
Most of the commercial nanofiltration membranes are composite nanofiltration membranes obtained by interfacial polymerization of polyamines and polyacid chlorides on ultrafiltration membranes with non-woven fabrics. During the operation of the membrane, membrane fouling is caused by inorganic salt scale, colloid, organic matter and other factors in the environment, resulting in a decrease in water quality and water flux so that a significant reduction in membrane life and an increase in operating costs. Therefore, it is necessary to improve the pollution resistance of the film. The hydrophilic modification of the membrane can improve the anti-pollution performance of the membrane. This paper discusses the preparation and research progress of the hydrophilic composite nanofiltration membrane from three aspects: new monomer development, active layer modification and new base film development and the current research content is summarized and some of the contents that need urgent research are proposed.
Control of the emission of NOx during coal combustion by inhibiting the formation of NOx precursor in the pyrolysis process
Authors: Zhang Kaixia , Shangguan Ju , Yang Song , Guo Sicong , Du Wenguang , Liu Shoujun , Chen Lili , Shi Pengzheng 
Published: September 2019

Abstract
NOX emitted from coal combustion cause serious pollution to the ecological environment. At present, controlling and reducing NOX emissions has become one of the most important technologies to control the pollutants in the atmosphere. Due to the formation of a large amount of NOX precursor HCN, NH3, char-N during coal pyrolysis, and these nitrogen species with O2 in the air cause the emissions of NOx during combustion. Therefore, it is of great significance to study the control of NOX precursors during coal pyrolysis. The addition of additives to coal has an important catalytic effect on the control of NOX precursors during coal pyrolysis. In this paper, the catalytic effect of additive Fe, Ca, Na on nitrogen transport during pyrolysis of raw coal or demineralized coal was discussed. It can be concluded that Fe, Ca, Na can catalyze the conversion of NH3, HCN and char-N to N2, thus reducing the NOX precursor in the pyrolysis of coal and reducing the emission of NOX in the subsequent combustion process. The result provides an important scientific basis for the control of NOX emission by reducing NOX precursor formed in pyrolysis during coal combustion.
Study on the action law of key influencing factors of magnetic field strength of magnetic filter material
Authors: Wang Xiaoyu , Wang Jiabin , Qiu Liping , Zhang Dong , Li Tianhang 
Published: September 2019

Abstract
In recent years, the application of magnetic field technology in the field of water treatment has been relatively mature. The common ways of adding magnetic field are external magnetic field and internal magnetic powder. In order to solve the problem of uneven distribution of magnetic field caused by external mode and easy loss of magnetic powder caused by internal injection mode, this paper studied a preparation method of magnetic filter material used in biological filter tank, and studied the key influencing factors such as composition, particle size, magnetization time and times that affect magnetic field strength of filter material. The results show that the nanometer Fe3O4 content has a great influence on the magnetic field strength of the magnetic filter material. When the content is 16.6%, the magnetic field strength of the filter material is the best. The larger the particle size of the filter material is, the less the magnetic structure of the surface magnetization vector is not collinear, and the higher the internal coercivity is, the higher the magnetic field strength of the filter material is. The magnetic field intensity of the filter material increased gradually with the extension of magnetization time, and basically became saturated after 60min. Repeated magnetization can improve the initial magnetic field strength of the filter material, but has little effect on the stable magnetic field strength after magnetic recession.
Control of the NOx emissions by metal additive in-situ catalyze the reduction of NOx during combustion
Authors: Chen Lili , Shangguan Ju , Ma Yuchuan , Zhao Cong , Liu Shoujun , Yang Song , Du Wenguang , Zhang Kaixia , Shi Pengzheng 
Published: September 2019

Abstract
The emissions of NOx during combustion causes serious pollution to the environment. It is especially important to reduce NOx pollution during coal combustion through clean coal utilization. The use of civil clean coke, which is mainly prepared by mixing metal additives with coal, is one of the ways of clean coal utilization. In this work, a series of coke samples with loading metal additives were prepared by physical method, and the NOx emissions were investigated in a fixed bed reactor. The results show that Na, K, Mg, Ca, Cr, Fe, Co, Ni and Cu play in-situ catalytic effects on the NOx reduction reactions. It is of great practical value and scientific significance to the comprehensive treatment of NOx and the clean utilization process of coal.
The Development of Shale Gas Modularized Surface Engineering
Authors: Chen Yingjie , Zhang Baosheng 
Published: September 2019

Abstract
Shale gas is one of the most important unconventional natural gas, which is an effective clean energy and has bright future. However, because of the characteristic of shale gas reserve, the conventional construction mode cannot be used to explore shale gas. With the development of 3D design software, the modularized engineering is gradually becoming the solution. The standardized engineering plays a key role to promote developing level of modules by several ways. These standardized modules can be transferred and reused in other wells. The whole project can be assembly design with standardized modules. The information technique is also applied into module engineering to improve the efficiency of operation monitoring and control. The shale gas surface engineering project is becoming like product, and it will cause a new evolution of project management and shale gas exploration.