scholarly journals Properties of the Iron Bacteria Biofouling on Ni–P–rGO Coating

2020 ◽  
Vol 10 (5) ◽  
pp. 1567
Author(s):  
Zhiming Xu ◽  
Mingyang Sun ◽  
Zuodong Liu ◽  
Bingbing Wang ◽  
Huishuang Di
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Heat Exchange ◽  
Carbon Steel ◽  
Surface Coating ◽  
Coating Solution ◽  
Iron Bacteria ◽  
Heat Transfer Efficiency ◽  
Reduced Graphene ◽  
Scanning Electron

Biofouling on heat exchange devices can decrease heat transfer efficiency, corrode materials, and even lead to safety accidents. Most heat exchange devices are made of carbon steel that efficiently produces biofouling. However, in this paper, a nickel–phosphorus–reduced graphene oxide (Ni–P–rGO) coating was prepared on carbon steel by electroless plating to investigate the properties of iron bacteria biofouling. The surface coating was analyzed via scanning electron microscopy and Raman spectroscopy. After the carbon steel and the Ni–P–rGO coating were immersed into an iron bacteria solution for 120 h, the weight of the iron bacteria biofouling on the Ni–P–rGO coating sharply decreased when compared with the carbon steel. We can conclude that the concentration of graphene can affect the weight of iron bacteria biofouling. We also found that the coating solution with 40 mg/L of graphene performed the best in inhibiting biofouling by decreasing the weight of the biofouling by 97.2% compared to carbon steel.

scholarly journals Properties of Iron Bacteria Biofouling on Ni-P-rGO Coating under Flowing Conditions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 764
Author(s):  
Mingyang Sun ◽  
Zhiming Xu ◽  
Zuodong Liu ◽  
Bingbing Wang ◽  
Huishuang Di
Keyword(s):  
Heat Exchange ◽  
Carbon Steel ◽  
Advanced Materials ◽  
Fouling Resistance ◽  
Asymptotic Value ◽  
Advanced Material ◽  
Iron Bacteria ◽  
Heat Transfer Efficiency ◽  
Reduced Graphene ◽  
Different Temperatures

Biofouling on heat exchange devices can decrease heat transfer efficiency, corrode materials, and even lead safety accidents. Most heat exchange devices are made of carbon steel, which produces biofouling easily. In this paper, nickel-phosphorus-reduced graphene oxide (Ni-P-rGO) coating was prepared on carbon steel by electroless plating as a kind of advanced material to study the properties of iron bacteria biofouling under flowing conditions. The coating was analyzed via scanning electron microscopy and Raman spectroscopy. The properties of iron bacteria biofouling on carbon steel and Ni-P-rGO coating were then compared under flowing conditions. Compared with carbon steel, the asymptotic value of fouling resistance on the Ni-P-rGO coating significantly decreased. Additionally, the induction period and the time of reaching the asymptotic value greatly increased. The inhibition properties of biofouling of advanced materials Ni-P-rGO coating under different temperatures, flow velocities, and initial concentrations was also studied.

scholarly journals Thermo-Hydraulic Performance of U-Tube Borehole Heat Exchanger with Different Cross-Sections

2021 ◽  
Vol 13 (6) ◽  
pp. 3255
Author(s):  
Aizhao Zhou ◽  
Xianwen Huang ◽  
Wei Wang ◽  
Pengming Jiang ◽  
Xinwei Li
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Resistance ◽  
Cross Sections ◽  
Three Dimensional ◽  
Thermal Response ◽  
Transfer Efficiency ◽  
Cross Sectional ◽  
Heat Transfer Efficiency ◽  
Oval Tube

For reducing the initial GSHP investment, the heat transfer efficiency of the borehole heat exchange (BHE) system can be enhanced to reduce the number or depth of drilling. This paper proposes a novel and simple BHE design by changing the cross-sectional shape of the U-tube to increase the heat transfer efficiency of BHEs. Specifically, in this study, we (1) verified the reliability of the three-dimensional numerical model based on the thermal response test (TRT) and (2) compared the inlet and outlet temperatures of the different U-tubes at 48 h under the premise of constant leg distance and fluid area. Referent to the circular tube, the increases in the heat exchange efficiencies of the curved oval tube, flat oval tube, semicircle tube, and sector tube were 13.0%, 19.1%, 9.4%, and 14.8%, respectively. (3) The heat flux heterogeneity of the tubes on the inlet and outlet sides of the BHE, in decreasing order, is flat oval, semicircle, curved oval, sector, and circle shapes. (4) The temperature heterogeneity of the borehole wall in the BHE in decreasing order is circle, sector, curved oval, flat oval, and semicircle shapes. (5) Under the premise of maximum leg distance, referent to the heat resistance of the tube with a circle shape at 48 h, the heat exchange efficiency of the curved oval, flat oval, semicircle, and sector tubes increased 12.6%, 17.7%, 10.3%, and 7.8%, respectively. (6) We found that the adjustments of the leg distance and the tube shape affect the heat resistance by about 25% and 12%, respectively. (7) The flat-oval-shaped tube at the maximum leg distance was found to be the best tube design for BHEs.

Microstructure and Properties of Boronized Layer Produced by Borosulphurizing Method

2012 ◽  
Vol 562-564 ◽  
pp. 204-207
Author(s):  
Dong Wang ◽  
Hui Qin Li ◽  
Han Yu Zhao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Optical Microscope ◽  
Boride Layer ◽  
Microstructure And Properties ◽  
Scanning Electron ◽  
Microhardness Tester

In this study, 45 carbon steel was boronized and borosulphurized at 950°C for 2, 3， 4, 5, 6 and 8 h, respectively. The samples were characterized by scanning electron microscopy, optical microscope, microhardness tester and ring-on-block wear tester. It is found that the surface of borosulphurized samples was dense, compact and relatively smooth; Although the boride layers produced by boro- sulphurizing at 950°C showed a lower microhardness value compared with that produced by boronizing, the wear resistance of the borosulphurized carbon steel is higher than that of boronized sample due to formation of FeS phase in the boride layer.

scholarly journals Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Electron

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.

The Influence of the Addition of rGO and CNT on the Electrochemical Properties of the Batteries the LaNi-Based Battery Alloys

2020 ◽  
Vol 1012 ◽  
pp. 153-157
Author(s):  
Edson Pereira Soares ◽  
J.C.S. Filho ◽  
J.C.S. Casini ◽  
R.N. Faria ◽  
Hidetoshi Takiishi
Keyword(s):  
Electron Microscopy ◽  
Discharge Capacity ◽  
Cast Alloy ◽  
Negative Electrode ◽  
Cyclic Stability ◽  
X Ray Diffraction ◽  
Electrochemical Test ◽  
X Ray ◽  
Reduced Graphene ◽  
Scanning Electron

In this article the results of the negative electrode performance produced by La0.7Mg0.3Al0.3Mn0.4Co0.5Ni3.8 as-cast alloy adding 1 to 10% of carbon nanotube (CNT) or reduced graphene oxide (rGO) were investigated as Ni-MH batteries. The as cast alloy were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The CNT and rGO were characterized by high resolution SEM-FEG. The discharge capacity obtained during the electrochemical characterization showed that in the addition of 1% rGO the discharge capacity was 332 mAh and 1% CNT 364 mAh , being that the rGO batteries maintaining better cyclic stability during the electrochemical test.

SEM Studies on the Microstructure and Phase Composition Distribution in Cr3C2 + TiC Claddings on Low-Carbon Steel

2020 ◽  
Vol 303 ◽  
pp. 59-66
Author(s):  
Konstantin V. Ivanov ◽  
Vladimir E. Ovcharenko
Keyword(s):  
Electron Microscopy ◽  
Phase Composition ◽  
Carbon Steel ◽  
Structural Parameters ◽  
Low Carbon Steel ◽  
Relativistic Energy ◽  
Low Carbon ◽  
Composition Distribution ◽  
X Ray ◽  
Scanning Electron

Using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) we studied the distribution of structural parameters, phase composition and alloying elements concentration across the coatings obtained by cladding of chromium and titanium carbides mixture on low-carbon steel. The beam of relativistic energy electrons extracted into the atmosphere was used to form the coatings. The homogeneity in the allying elements distribution is shown to be defined by the lifetime of the melt bath while the phase composition distribution depends on the thickness of the melt layer. Both above parameters are determined by the density of the entered energy.

scholarly journals Scanning Electron Microscopy Characterization of Carbon Steel Fractured by Pressure while Exposed to Cryogenic Temperatures

2010 ◽  
Vol 16 (S2) ◽  
pp. 1260-1261 ◽  
Author(s):  
MW Pendleton ◽  
C Mazzella
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Steel ◽  
Cryogenic Temperatures ◽  
Microscopy Characterization ◽  
Scanning Electron Microscopy Characterization ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

scholarly journals Synthesis and thermal conductivity of functionalized biocarbon-Fe3O4 nanocomposite-based green nanofluid for heat transfer applications

2021 ◽  
Vol 321 ◽  
pp. 01003
Author(s):  
Divya Barai ◽  
Sohan Parbat ◽  
Bharat Bhanvase
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Nanocomposite Particles ◽  
X Ray ◽  
Conductivity Enhancement ◽  
Water Based ◽  
One Step ◽  
Ultrasound Assisted ◽  
Scanning Electron

Bio-based graphitic carbon was synthesized in this work by one-step carbonization of bamboo waste at low temperature. This bio-based carbon was then functionalized in order to decorated it with Fe3O4 nanoparticles. The functionalized biocarbon-Fe3O4 (f-biocarbon-Fe3O4) nanocomposite was synthesized using ultrasound-assisted coprecipitation method which was then confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffractometry. Water-based nanofluid was prepared using the synthesized f-biocarbon-Fe3O4 nanocomposite particles. Thermal conductivity of this nanofluid was analyzed at different concentrations and temperatures. A thermal conductivity enhancement of almost 80% was recorded at 35°C for nanofluid containing 0.1 vol.% of f-biocarbon-Fe3O4 nanocomposite particles compared to water. Also, empirical model is developed for prediction of thermal conductivity as a function of concentration and temperature of bamboo waste-derived f-biocarbon-Fe3O4 nanocomposite-based green nanofluid.

scholarly journals The Influence of the Preparation and Stability of Nanofluids for Heat Transfer

2019 ◽  
Vol 25 (4) ◽  
pp. 45-54 ◽  
Author(s):  
Noor Sabih Majeed ◽  
Basma A. Abdulmajeed ◽  
Anwar Khudhur Yaseen
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Base Fluid ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Scanning Electron

Recently the use of nanofluids represents very important materials. They are used in different branches like medicine, engineering, power, heat transfer, etc. The stability of nanofluids is an important factor to improve the performance of nanofluids with good results. In this research two types of nanoparticles, TiO2 (titanium oxide) and γ-Al2O3 (gamma aluminum oxide) were used with base fluid water. Two-step method were used to prepare the nanofluids. One concentration 0.003 vol. %, the nanoparticles were examined. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray diffraction (XRD) were used to accomplish these tests. The stability of the two types of nanofluids is measured by zeta potential and UV-vis spectrophotometer. The results showed that γ-Al2O3/water has more stable than TiO2/ water for the same period of time.  

scholarly journals Facile and green synthesis of silver nanoparticle-reduced graphene oxide composite and its application as nonenzymatic electrochemical sensor for hydrogen peroxide

2021 ◽  
pp. 295-308 ◽  
Author(s):  
Jagdish C. Bhangoji ◽  
Srikant Sahoo ◽  
Ashis Kumar Satpati ◽  
Suresh S. Shendage
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Metal Foil ◽  
Reduced Graphene ◽  
Scanning Electron

A simple and environment friendly protocol has been developed for the synthesis of Ag nanoparticles (AgNPs) supported on reduced graphene oxide (rGO) with copper metal foil as reductant. The prepared AgNPs-rGO, nanocomposite was characterized by various analytical techniques such as scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD). The electrochemical performance of the material has been evaluated using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The average crystallite size of AgNPs is found to be 32.34 nm. The application of prepared electrocatalyst (AgNPs-rGO) as a non-enzymatic sensor is examined through the modified electrode with the synthesized AgNPs-rGO. The sensor showed excellent performance toward H2O2 reduction with a sensitivity of 12.73 µA.cm-2.mM-1, with a linear dynamic range of 1.5 µM – 100 mM, and the detection limit of 1.90 µM (S/N = 3). Furthermore, the sensor displayed high sensitivity, reproducibility, stability and selectivity for the determination of H2O2. The results demonstrated that AgNPs-rGO has potential applications as sensing material for quantitative determination of H2O2.

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