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Khalid Mohammed Ridha W, Reza Kashyzadeh K, Ghorbani S. Common Failures in Hydraulic Kaplan Turbine Blades and Practical Solutions. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093303. [PMID: 37176185 PMCID: PMC10179411 DOI: 10.3390/ma16093303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
Kaplan turbines, as one of the well-known hydraulic turbines, are generally utilized worldwide for low-head and high-flow conditions. Any failure in each of the turbine components can result in long-term downtime and high repair costs. In a particular case, if other parts are damaged due to the impact of the broken blades (e.g., the main shaft of the turbine), the whole power plant may be shut down. On the other hand, further research on the primary causes of failures in turbines can help improve the present failure evaluation methodologies in power plants. Hence, the main objective of this paper is to present the major causes of Kaplan turbine failures to prevent excessive damage to the equipment and provide practical solutions for them. In general, turbines are mainly subjected to both Internal Object Damage (IOD) and Foreign Object Damage (FOD). Accordingly, this paper presents a state-of-the-art review of Kaplan turbine failures related to material and physical defects, deficiencies in design, deficits in manufacturing and assembly processes, corrosion failures, fatigue failure, cavitation wear, types of cavitation in hydro turbines, hydro-abrasive problems, and hydro-erosion problems. Eventually, the authors have attempted to discuss practical hints (e.g., nanostructured coatings) to prevent damages and improve the performance of Kaplan turbines.
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Affiliation(s)
- Waleed Khalid Mohammed Ridha
- Department of Mechanical Engineering Technologies, Academy of Engineering, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia
| | - Kazem Reza Kashyzadeh
- Department of Transport, Academy of Engineering, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia
| | - Siamak Ghorbani
- Department of Mechanical Engineering Technologies, Academy of Engineering, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia
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Shamsabadipour A, Pourmadadi M, Rashedi H, Yazdian F, Navaei-Nigjeh M. Nanoemulsion carriers of porous γ-alumina modified by polyvinylpyrrolidone and carboxymethyl cellulose for pH-sensitive delivery of 5-fluorouracil. Int J Biol Macromol 2023; 233:123621. [PMID: 36773864 DOI: 10.1016/j.ijbiomac.2023.123621] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
5-Fluorouracil (5-FU) is a cytotoxic drug with a low half-life. These features can cause some problems such as burst drug release and numerous side effects. In the present study, a pH-sensitive nanocomposite of polyvinylpyrrolidone (PVP)/carboxymethyl cellulose (CMC)/γ-alumina developed by using water in oil in water (W/O/W) double emulsion method. The fabricated emulsion has been employed as the 5-FU carrier to investigate its effects on drug half-life, side effects, drug loading efficiency (DLE), and drug entrapment efficiency (DEE). Analyzing the FTIR and XRD indicated the successful loading of 5-FU into the nanocarrier and affirmed the synthesized nanocomposite's chemical bonding and crystalline features. Furthermore, by using DLS and Zeta potential assessment, size and undersize distribution, as well as the stability of the drug-loaded nanocomposite were determined, which demonstrated the monodisperse and stable nanoparticles. Moreover, the nanocomposites with spherical shapes and homogeneous surfaces were shown in FE-SEM, which indicated good compatibility for the constituents of the nanocomposites. Moreover, by employing BET analysis the porosity has been investigated. Drug release pattern was studied, which indicated a controlled drug release behavior with above 96 h drug retention. Besides, the loading and entrapment efficiencies were obtained 44 % and 86 %, respectively. Furthermore, the curve fitting technique has been employed and the predominant release mechanism has been determined to evaluate the best-fitted kinetic models. MTT assay and flow cytometry assessment has been carried out to investigate the cytotoxic effects of the fabricated drug-loaded nanocomposite on MCF-7 and normal cells. The results showed enhanced cytotoxicity and late apoptosis for the PVP/CMC/γ-alumina/5-FU. Based on the MTT assay outcomes on normal cell lines (L929), which indicated above 90 % cell viability, the biocompatibility and biosafety of the synthesized nanocarrier have been confirmed. Moreover, due to the porosity of the PVP/CMC/γ-alumina, this nanocarrier can exploit from high specific surface area and be more sensitive to environmental conditions such as pH. These outcomes propose that the novel pH-sensitive PVP/CMC/γ-alumina nanocomposite can be a potential candidate for drug delivery applications, especially for cancer therapy.
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Affiliation(s)
- Amin Shamsabadipour
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Mehrab Pourmadadi
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Hamid Rashedi
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
| | - Fatemeh Yazdian
- Department of Life Science Engineering, Faculty of New Science and Technologies, University of Tehran, Tehran, Iran.
| | - Mona Navaei-Nigjeh
- Pharmaceutical Sciences Research Center, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
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Mi B, Wang Q, Xu Y, Qin Z, Chen Z, Wang H. Improvement in Corrosion Resistance and Interfacial Contact Resistance Properties of 316L Stainless Steel by Coating with Cr, Ti Co-Doped Amorphous Carbon Films in the Environment of the PEMFCs. Molecules 2023; 28:molecules28062821. [PMID: 36985793 PMCID: PMC10057137 DOI: 10.3390/molecules28062821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 03/30/2023] Open
Abstract
In order to obtain films with high corrosion resistance and excellent interfacial contact resistance (ICR) on 316L stainless steel used for bipolar plates in proton-exchange membrane fuel cells (PEMFCs), Cr, Ti co-doped amorphous carbon films were prepared on 316L stainless steel. The preparation method for the coating was magnetron sputtering. The doping amount of the Ti element was controlled by a Cr target and a Ti target current. The change in the structure and properties of the coating after the change from Cr single-element doping to Cr and Ti co-doping was studied. The change rule of the structure and properties of the coating from Cr single-element doping to Cr and Ti co-doping was studied. An increase in the Ti content led to a decreased grain boundary, a flatter surface, and a higher sp2-hybridized carbon content. TiC and CrC nanocrystals were formed in the amorphous carbon structure together. The amorphous carbon films doped with Cr and Ti simultaneously achieved a low ICR and high corrosion resistance compared with single-Cr-doped amorphous carbon. The enhanced corrosion resistance was attributed to the decreasing grain boundary, the formation of the TiC crystal structure, and the smaller grain size. The best performance was obtained at a Ti target current of 2A. Compared with bare 316L stainless steel, the corrosion resistance of Cr, Ti co-doped amorphous carbon (Icorr = 5.7 × 10-8 A/cm2, Ti-2 sample) was greatly improved. Because Ti doping increased the content of sp2-hybridized carbon in the coating, the contact resistance of the coating decreased. Moreover, the interfacial contact resistance was 3.1 mΩ·cm2 in the Ti-2 sample, much lower than that of bare 316L stainless steel. After the potentiostatic polarization test, the coating still had excellent conductivity.
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Affiliation(s)
- Baosen Mi
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Quan Wang
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Yuhao Xu
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Ziwei Qin
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
- Panxing Technology Zhejiang Co., Ltd., Jinhua 321000, China
| | - Zhuo Chen
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
- Panxing Technology Zhejiang Co., Ltd., Jinhua 321000, China
| | - Hongbin Wang
- Panxing Technology Zhejiang Co., Ltd., Jinhua 321000, China
- Institute of Materials Science, Shanghai DianJi University, Shanghai 201306, China
- Shanghai Engineering Research Centre for Metal Parts Green Remanufacture, Shanghai 200444, China
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Xuan J, Liu Y, Xu L, Xin Y, Xue L, Li L. Properties of SS304 Modified by Nickel-Cobalt Alloy Coating with Cauliflower-Shaped Micro/Nano Structures in Simulated PEMFC Cathode Environment. NANOMATERIALS 2022; 12:nano12121976. [PMID: 35745315 PMCID: PMC9228718 DOI: 10.3390/nano12121976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/27/2022] [Accepted: 06/08/2022] [Indexed: 02/01/2023]
Abstract
This study presents the corrosion behavior and surface properties of SS304 modified by electrodeposited nickel-cobalt (Ni-Co) alloy coating with cauliflower-shaped micro/nano structures (Ni-Co/SS304) in the simulated PEMFC cathodic environment. The hydrophobicity of the as-prepared Ni-Co alloy coating can be improved simply by low-temperature annealing. The morphology and composition of the Ni-Co/SS304 were analyzed and characterized by SEM, EDS, XRD, and XPS. The polarization, wettability, and ICR tests were respectively conducted to systemically evaluate the performance of Ni-Co/SS304 in the simulated PEMFC cathode environment. As revealed by the results, the Ni-Co/SS304 can maintain its hydrophobicity under hot-water droplets as high as 80 °C and demonstrates higher conductivity than the bare SS304 substrate before and after polarization (0.6 V vs. SCE, 5 h), which is of great significance to improve the surface hydrophobicity and conductivity of bipolar plates.
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Affiliation(s)
- Junji Xuan
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; (J.X.); (L.X.); (L.L.)
- State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute, Qingdao 266237, China; (Y.L.); (Y.X.)
| | - Yueren Liu
- State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute, Qingdao 266237, China; (Y.L.); (Y.X.)
| | - Likun Xu
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; (J.X.); (L.X.); (L.L.)
- State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute, Qingdao 266237, China; (Y.L.); (Y.X.)
- Correspondence:
| | - Yonglei Xin
- State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute, Qingdao 266237, China; (Y.L.); (Y.X.)
| | - Lili Xue
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; (J.X.); (L.X.); (L.L.)
| | - Li Li
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; (J.X.); (L.X.); (L.L.)
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Performance of SS304 Modified by Silver Micro/Nano-Dendrite Coating with Hot-Water Super-Repellency in Simulated PEMFC Cathode Environment. NANOMATERIALS 2022; 12:nano12101726. [PMID: 35630946 PMCID: PMC9145656 DOI: 10.3390/nano12101726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/14/2022] [Accepted: 05/16/2022] [Indexed: 02/04/2023]
Abstract
In this study, an silver (Ag) plating with micro/nano-dendrite structures is prepared on the 304 stainless steel (SS304) surface by potentiostatic deposition (Ag/SS304). After being modified by n-dodecyl mercaptan (NDM) with the low surface energy, the obtained sample (NDM@Ag/SS304) exhibits stable superhydrophobicity and excellent hot-water repellency. The surface morphology and composition of NDM@Ag/SS304 are analyzed by scanning electron microscope (SEM), X-ray spectrometer (EDS), X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS) characterization. The electrochemical measurements, tests of water contact angle (WCA), and interfacial contact resistance (ICR) are employed to systematically study the performance of the NDM@Ag/SS304 in the simulated cathode environment of proton exchange membrane fuel cell (PEMFC). The results show that the NDM@Ag/SS304 has high corrosion potential (~0.25 V) and low corrosion current density (~4.04 μA/cm2); after potentiostatic polarization (0.6 V, 5 h), the NDM@Ag/SS304 also shows high superhydrophobic stability.
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