scholarly journals Experimental Study on Foci Development in Mortar Using Seawater and Sand

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1799 ◽  
Author(s):  
Yajun WANG ◽  
Chuhan ZHANG ◽  
Jinting WANG ◽  
Yanjie XU ◽  
Feng JIN ◽  
...  
Keyword(s):  
Damage Detection ◽  
Energy Dispersive Spectrometer ◽  
Natural Seawater ◽  
Interfacial Behavior ◽  
X Ray Diffraction ◽  
Computer Tomography Scan ◽  
On Line ◽  
Composition Optimization ◽  
Helical Computer Tomography ◽  
Saline Minerals

Mortar using seawater and sand was the material studied here. The mortar specimens, in particular, were cured in natural seawater. The foci development in the mortar was the principal interest in this study. The on-line damage detection experiment art, including dynamically global MSHCT (Multi-Slices Helical Computer Tomography) scan and the local detection of EDS (Energy Dispersive Spectrometer), SEM (Scanning Electron Microscopy), and XRD (X-ray Diffraction) was designed to research the foci development in the mortar specimen. The mortar specimens with 70-day age were produced and investigated by the on-line damage detection experiments. The experiment results indicated that the mortar using seawater and sand offered appreciable strength at the early age, at least, although some saline minerals were generated during the preparation. The residual strength of the mortar was above 13 MPa, which helped to prevent the sharp damage of engineering bodies. The micro-interfacial behavior and the parental foci development controlled the damage evolution in the mortar using seawater and sand, the performance of which was still the adjustable one by composition optimization.

scholarly journals Experimental and Physico-Chemical Comparison of ZnO Nanoparticles’ Activity for Photocatalytic Applications in Wastewater Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 678
Author(s):  
Stefano Alberti ◽  
Irene Basciu ◽  
Marco Vocciante ◽  
Maurizio Ferretti
Keyword(s):  
Wastewater Treatment ◽  
Zno Nanoparticles ◽  
Energy Dispersive Spectrometer ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Commercial Sample ◽  
Synthetic Process ◽  
Physico Chemical ◽  
Photocatalytic Applications ◽  
Reflectance Measurements

In this contribution, the photoactivity upon activation by simulated sunlight of zinc oxide (ZnO) obtained from two different synthetic pathways (Acetate and Nitrate) is investigated for water purification. Different reagents and processes were exploited to obtain ZnO nanoparticles. Products have been characterized by means of X-Ray Diffraction, Scanning Electron Microscopy along with Energy Dispersive Spectrometer, Dynamic Light Scattering, and Diffuse Reflectance Measurements, to highlight the different outcomes ascribable to each synthesis. A comparison of characteristics and performances was also carried out with respect to commercial ZnO. Nanoparticles of this semiconductor can be obtained as aggregates with different degrees of purity, porosity, and shape, and their physical-chemical properties have been addressed to the specific use in wastewater treatment, testing their effectiveness on the photocatalytic degradation of methylene blue (MB) as a model pollutant. Excluding the commercial sample, experimental results evidenced a better photocatalytic behavior for the ZnO Nitrate sample annealed at 500 °C, which was found to be pure and stable in water, suggesting that ZnO could be effectively exploited as a heterogeneous photocatalyst for the degradation of emerging pollutants in water, provided that thermal treatment is included in the synthetic process.

scholarly journals Extraction of Boron from Ludwigite Ore: Mechanism of Soda-Ash Roasting of Lizardite and Szaibelyite

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 533 ◽  
Author(s):  
Xin Zhang ◽  
Guanghui Li ◽  
Jinxiang You ◽  
Jian Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Energy Dispersive Spectrometer ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Selective Activation ◽  
X Ray ◽  
Shed Light ◽  
Soda Ash ◽  
Scanning Electron

Ludwigite ore is a typical low-grade boron ore accounting for 58.5% boron resource of China, which is mainly composed of magnetite, lizardite and szaibelyite. During soda-ash roasting of ludwigite ore, the presence of lizardite hinders the selective activation of boron. In this work, lizardite and szaibelyite were prepared and their soda-ash roasting behaviors were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analyses, in order to shed light on the soda-ash activation of boron within ludwigite ore. Thermodynamics of Na2CO3-MgSiO3-Mg2SiO4-Mg2B2O5 via FactSage show that the formation of Na2MgSiO4 was preferential for the reaction between Na2CO3 and MgSiO3/Mg2SiO4. While, regarding the reaction between Na2CO3 and Mg2B2O5, the formation of NaBO2 was foremost. Raising temperature was beneficial for the soda-ash roasting of lizardite and szaibelyite. At a temperature lower than the melting of sodium carbonate (851 °C), the soda-ash roasting of szaibelyite was faster than that of lizardite. Moreover, the melting of sodium carbonate accelerated the reaction between lizardite with sodium carbonate.

Preparation and Characterization of Zn-Containing Hydroxyapatite/TiO2 Composite Coatings on Ti Alloys

2011 ◽  
Vol 685 ◽  
pp. 367-370 ◽  
Author(s):  
Min Qi ◽  
Da Yi Yang ◽  
Jing Ying Zhang ◽  
Hong Jun Ai
Keyword(s):  
Adhesion Strength ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Zn Content ◽  
Micro Arc Oxidation ◽  
Gel Technique ◽  
Bacteria Resistance

In order to improve the osteoblast growth and bacteria resistance, Zn-containing hydroxyapatite (Zn-HA) and titanium oxide (TiO2) composite coatings were prepared to improve binding between coating and Ti substrate. TiO2 film was prepared on the surface of Ti by micro-arc oxidation (MAO) and Zn-HA coating was deposited on TiO2 using sol–gel technique. Phase structure, composition and microstructure of the surface coatings were analyzed by X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS), respectively. The adhesion strength between the coatings with different Zn content was measured by tensile testing. The results showed that there was no significant influence of Zn content on adhesion strength between coating and Ti substrate.

Research on the Microstructure and Microhardness of 9Cr18 Semi-Solid Billet

2015 ◽  
Vol 817 ◽  
pp. 278-282 ◽  
Author(s):  
Yong Jin Wang ◽  
Ren Bo Song ◽  
Ya Ping Li ◽  
Ruo Ling Bi
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Eutectic Structure ◽  
X Ray Diffraction ◽  
Graded Materials ◽  
Primary Austenite ◽  
Secondary Austenite ◽  
Austenite Grains ◽  
Semi Solid ◽  
Sloping Plate ◽  
Eutectic Area

Formed in the semi-solid state, materials can obtain unconventional microstructures and properties compared with traditional method. In this paper, semi-solid billet of 9Cr18 steel was obtained through a wavelike sloping plate. Microstructure analysis of the semi-solid billet was conducted through scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). X-ray diffraction (XRD) test and microhardness test were also used to analyze the properties. The results showed that the structure of 9Cr18 semi-solid billet contained globular primary austenite and secondary austenite-Cr7C3 eutectic. Globular primary austenite grains were first formed during partial solidification in the sloping plate, and then the rest liquid metal formed secondary austenite and Cr7C3 eutectic structure surrounding the primary grains. Cr atoms had a concentration in the rest liquid side, which along with C atoms contributed to the formation of the Cr7C3 carbide. Hardness in the primary solid grain area and the eutectic area was about 330 HV and 650 HV, respectively. These specific properties were important for subsequent thixoforming of the functional graded materials.

scholarly journals Morphology and Elemental Composition of Product Obtained from Struvite Fluidized Bed Reactor

2018 ◽  
Vol 28 (2) ◽  
pp. 139-149
Author(s):  
Franciszek Bydałek ◽  
Anna Kula ◽  
Jacek Mąkinia
Keyword(s):  
Fluidized Bed ◽  
Energy Dispersive Spectrometer ◽  
Treatment Plant ◽  
Fluidized Bed Reactor ◽  
Pilot Scale ◽  
X Ray Diffraction ◽  
Distant Future ◽  
Struvite Precipitation ◽  
Ph Level ◽  
Highly Porous

Abstract Phosphorus scarcity is no longer a distant future, therefore the idea of phosphoru recovery is currently widely adopted and developed. Technologies based on the struvite precipitation are consider to address the future P challenges in the optimum way. This paper presents the results of the pilot scale implementation of fluidized bed reactor for struvite precipitation at the wastewater treatment plant. The test was carried out to assess the applicability of the technology in terms of robustness and final product quality, operating at low pH level (7,5-7,8). Obtained struvite pellets were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS). The presence of foreign ions and particulate impurities in the feed source, affected the uniform growth of the crystal structure, resulting in highly porous structure of the pellets. Despite the varying physiochemical conditions, typical for wastewater, obtained pellets were determined with 95% struvite purity.

MICROSTRUCTURE AND BLUE PHOTOLUMINESCENCE OF HYDROGENATED SILICON CARBONITRIDE THIN FILMS

2019 ◽  
Vol 26 (04) ◽  
pp. 1850177 ◽  
Author(s):  
YINQIAO PENG ◽  
JICHENG ZHOU ◽  
GUIBIN LEI ◽  
YUANJU GAN ◽  
YUEFENG CHEN
Keyword(s):  
Thin Films ◽  
Network Structure ◽  
Energy Dispersive Spectrometer ◽  
Silicon Carbonitride ◽  
X Ray Diffraction ◽  
Hydrogenated Silicon ◽  
X Ray ◽  
Atomic Force ◽  
Scanning Electron ◽  
Blue Photoluminescence

Hydrogenated silicon carbonitride (SiCN:H) thin films were deposited by sputtering of silicon carbide target in hydrogen-doped argon and nitrogen atmospheres. The properties of the SiCN:H films were analyzed by scanning electron microscopy with energy dispersive spectrometer, atomic force microscope, Fourier transform infrared spectroscopy, X-ray diffraction and fluorescence spectrophotometer. No distinct crystal was formed in the SiCN:H films as-deposited and annealed at 600∘C and 800∘C. The SiCN:H films were mainly composed of Si–N, Si–C, Si–O, C–C, C–N, C[Formula: see text]N, N–Hn bonds and SiCxNy network structure. The strong blue photoluminescence observed from the SiCN:H film annealed at 600∘C was attributed to SiCxNy network structure.

The transformation of corrosion products on 0Cu2Cr carbon steel in the marine

2021 ◽  
Vol 68 (5) ◽  
pp. 457-463
Author(s):  
Hongyu Liu ◽  
Yingxue Teng ◽  
Jing Guo ◽  
Qinghe Xiao ◽  
Miao Wang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Energy Dispersive Spectrometer ◽  
Low Carbon Steel ◽  
Transformation Process ◽  
Corrosion Products ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
Content Type ◽  
Marine Engineering

Purpose This paper aims to explore the transformation process and transformation mechanism of carbon steel under the marine environment. Design/methodology/approach In this paper, the transformation and rust layers corrosion products on 0Cu2Cr carbon steel with different cycles coupon test was investigated and deeply explored by scanning electron microscope, energy dispersive spectrometer, X-ray diffraction. Findings The results showed that the thickness of rust layers grew from 71.83 µm to 533.7 µm with increasing duration of corrosion. The initial corrosion product was γ-FeOOH, then part of the γ-FeOOH continued growing, and under the capillary action, the other part of the γ-FeOOH transformed to α-FeOOH. Originality/value To the best of the authors’ knowledge, this paper puts forward for the first time a new viewpoint of the development of corrosion products of low-carbon steel in two ways. This discovery provides a new idea for the future development of steel for marine engineering.

scholarly journals Properties and Reaction Mechanisms of Magnesium Phosphate Cement Mixed with Ferroaluminate Cement

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2561 ◽  
Author(s):  
Liang Jia ◽  
Fangli Zhao ◽  
Jian Guo ◽  
Kai Yao
Keyword(s):  
Water Resistance ◽  
Energy Dispersive Spectrometer ◽  
Setting Time ◽  
Cementitious Materials ◽  
Magnesium Phosphate ◽  
Curing Time ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Composite Cement ◽  
Hydrated Product

A certain amount of ferroaluminate cement (FAC) was substituted for MgO during the magnesium phosphate cement (MPC) preparation to obtain the MPC–FAC composite cement. The influence of FAC on the strength, water resistance, pH, and setting time of MPC–FAC composite cement were examined. The microstructure and chemical composition were also analyzed by adopting scanning electron microscopic energy-dispersive spectrometer and X-ray diffraction, respectively. The study showed that setting time of MPC–FAC composite cement was dramatically prolonged when FAC substitution for MgO was between 30 and 40 wt %. The strength of MPC–FAC did not decrease during the early curing time (1 h and 1 d), whereas it increased during the late curing time (3, 7, and 28 days). Moreover, the existence of FAC decreased the hydrated product K-struvite during the early curing time and thus dramatically enhanced the water-resistance of MPC–FAC. With the addition of FAC, a large number of cementitious materials of AFt and AFm, as well as flocculent colloidal substances of AH3, C–S–H, and FH3, were generated during the hydration of MPC, which were filled in the internal pore of the hydrate. Thus, the internal compactness of the sample increased, while the compact protective covering layer was generated on the surface to enhance the water resistance and strength in the late curing time.

Morphology Control of the Nano-MnO2 by Microwave Hydrothermal Synthesis

2012 ◽  
Vol 624 ◽  
pp. 47-50
Author(s):  
Shi Lei Zhang ◽  
Ben Niu ◽  
Enlei Qi ◽  
Lei Wang ◽  
Jie Qiang Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Energy Dispersive Spectrometer ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Microwave Assisted ◽  
Structure And Morphology ◽  
Microwave Hydrothermal ◽  
Scanning Electron

In this paper, KMnO4 was used as raw material, nano-MnO2 with different morphologies such as flowers globular, hollow tubular and rodlike were obtained by the microwave assisted hydrothermal synthesis under the acidic condition. The crystal structure and morphology of the resultant MnO2 were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM), respectively. The elements and content of samples were tested by Energy Dispersive Spectrometer (EDS). The influence of reaction temperature and holding time on crystal forms and morphologies of the MnO2 was analyzed.

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