Displaying publications 41 - 60 of 185 in total

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  1. Balasbaneh AT, Ramli MZ
    Environ Sci Pollut Res Int, 2020 Dec;27(34):43186-43201.
    PMID: 32734541 DOI: 10.1007/s11356-020-10141-3
    In recent years, off-site volumetric construction has been promoted as a viable strategy for improving the sustainability of the construction industry. Most prefabricated prefinished volumetric construction (PPVC) structures are composed of either steel or concrete; thus, it is imperative to carry out life cycle assessments (LCAs) for both types of structures. PPVC is a method by which free-standing volumetric modules-complete with finishes for walls, floors, and ceilings-are prefabricated and then transferred and erected on-site. Although many studies have examined these structures, few have combined economic and environmental life cycle analyses, particularly for prefinished volumetric construction buildings. The purpose of this study is to utilize LCA and life cycle cost (LCC) methods to compare the environmental impacts and costs of steel and concrete PPVCs "from cradle to grave." The results show that steel necessitates higher electricity usage than concrete in all environmental categories, while concrete has a higher emission rate. Steel outperforms concrete by approximately 37% in non-renewable energy measures, 38% in respiratory inorganics, 43% in land occupation, and 40% in mineral extraction. Concrete, on the other hand, performs 54% better on average in terms of measures adopted for greenhouse gas (GHG) emissions. Steel incurs a higher cost in the construction stage but is ultimately the more economical choice, costing 4% less than concrete PPVC owing to the recovery, recycling, and reuse of materials. In general, steel PPVC exhibits better performance, both in terms of cost and environmental factors (excluding GHG emissions). This study endeavors to improve the implementation and general understanding of PPVC.
    Matched MeSH terms: Steel
  2. Sulaimon AA, Murungi PI, Tackie-Otoo BN, Nwankwo PC, Bustam MA
    Environ Sci Pollut Res Int, 2023 Dec;30(56):119309-119328.
    PMID: 37924403 DOI: 10.1007/s11356-023-30635-0
    Plant extracts have been shown to effectively inhibit metal corrosion. Using the Box-Behnken design, gravimetric, and electrochemical techniques, analyses were designed to investigate the anti-corrosion potential of okra in a 1M HCl medium. The inhibition performances derived from the various methods were in good agreement, demonstrating that physio-chemisorption was effective and adhered to the Langmuir isotherm model. The efficiency of okra mucilage extract was 96% at a much lower concentration compared to 91.2% and 88.4% for the unsieved extract and gelly-okra filtrate, respectively. FTIR results showed the presence of several functional groups in the okra mucilage extract that are associated with adsorption, and TGA analysis revealed that the extract has high thermal stability. FESEM analysis also supported evidence of adsorption. It was determined that corrosion inhibition by okra mucilage extract was primarily influenced by temperature, followed by extract concentration, with immersion time having the least effect. From the model optimization, it was observed that okra mucilage extract at 200 ppm, 60°C, and 24 h gave an inhibition efficiency of 89.98% and high desirability. These results demonstrate the high capacity of natural okra as an efficient biodegradable corrosion inhibitor.
    Matched MeSH terms: Steel
  3. Al-Amiery AA, Al-Majedy YK, Kadhum AA, Mohamad AB
    Molecules, 2014 Dec 29;20(1):366-83.
    PMID: 25551187 DOI: 10.3390/molecules20010366
    The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxy)acetohydrazide (EFCI), for mild steel (MS) in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM) was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT) was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy) and μ (dipole moment), and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies.
    Matched MeSH terms: Steel/chemistry*
  4. Abd Aziz SN, Pung SY, Ramli NN, Lockman Z
    ScientificWorldJournal, 2014;2014:252851.
    PMID: 24587716 DOI: 10.1155/2014/252851
    The photodegradation efficiency of ZnO nanoparticles in removal of organic pollutants deteriorates over time as a high percentage of the nanoparticles can be drained away by water during the wastewater treatment. This problem can be solved by growing the ZnO nanorods on stainless steel wire. In this work, ZnO nanorods were successfully grown on stainless steel wire by chemical vapour deposition. The SAED analysis indicates that ZnO nanorod is a single crystal and is preferentially grown in [0001] direction. The deconvoluted O 1s peak at 531.5 eV in XPS analysis is associated with oxygen deficient, revealing that the ZnO nanorods contain many oxygen vacancies. This observation is further supported by the finding of the small I(uv)/I(vis) ratio, that is, ~1 in the photoluminescence analysis. The growth of ZnO nanorods on stainless steel wire was governed by vapour-solid mechanism as there were no Fe particles observed at the tips of the nanorods. The photodegradation of Rhodamine B solution by ZnO nanorods followed the first-order kinetics.
    Matched MeSH terms: Stainless Steel/chemistry*
  5. Raba’atun Adawiyah Shamsuddin, Wan Ramli Wan Daud, Kim BH, Jamaliah Md. Jahim, Mimi Hani Abu Bakar, Wan Syaidatul Aqma Wan Mohd Noor
    Sains Malaysiana, 2018;47:3043-3049.
    Microbial fuel cells (MFCs) have a high potential application for simultaneous wastewater treatment and electricity
    generation. However, the choice of the electrode material and its design is critical and directly affect their performance.
    As an electrode of MFCs, the anode material with surface modifications is an attractive strategy to improve the power
    output. In this study, stainless steel (SS) and carbon steel (CS) was chosen as a metal anode, while graphite felt (GF)
    was used as a common anode. Heat treatment was performed to convert SS, CS and GF into efficient anodes for MFCs.
    The maximum current density and power density of the MFC-SS were achieved up till 762.14 mA/m2
    and 827.25 mW/m2
    ,
    respectively, which were higher than MFC-CS (641.95 mA/m2
    and 260.14 mW/m2
    ) and MFC-GF (728.30 mA/m2
    and 307.89
    mW/m2
    ). Electrochemical impedance spectroscopy of MFC-SS showed better catalytic activity compared to MFC-CS and
    MFC-GF anode, also supported by cyclic voltammetry test.
    Matched MeSH terms: Stainless Steel; Steel
  6. Nasution AK, Murni NS, Sing NB, Idris MH, Hermawan H
    J Biomed Mater Res B Appl Biomater, 2015 Jan;103(1):31-8.
    PMID: 24757071 DOI: 10.1002/jbm.b.33174
    This article describes the development of a partially degradable metal bone pin, proposed to minimize the occurrence of bone refracture by avoiding the creation of holes in the bone after pin removal procedure. The pin was made by friction welding and composed of two parts: the degradable part that remains in the bone and the nondegradable part that will be removed as usual. Rods of stainless steel 316L (nondegradable) and pure iron (degradable) were friction welded at the optimum parameters: forging pressure = 33.2 kPa, friction time = 25 s, burn-off length = 15 mm, and heat input = 4.58 J/s. The optimum tensile strength and elongation was registered at 666 MPa and 13%, respectively. A spiral defect formation was identified as the cause for the ductile fracture of the weld joint. A 40-µm wide intermetallic zone was identified along the fusion line having a distinct composition of Cr, Ni, and Mo. The corrosion rate of the pin gradually decreased from the undeformed zone of pure iron to the undeformed zone of stainless steel 316L. All metallurgical zones of the pin showed no toxic effect toward normal human osteoblast cells, confirming the ppb level of released Cr and Ni detected in the cell media were tolerable.
    Matched MeSH terms: Stainless Steel*
  7. Javanmardi A, Ibrahim Z, Ghaedi K, Khan NB, Benisi Ghadim H
    PLoS One, 2018;13(7):e0200482.
    PMID: 30059506 DOI: 10.1371/journal.pone.0200482
    This paper investigated the seismic retrofitting of an existing cable-stayed bridge through the use of a seismic isolation system. The bridge is situated in a high seismic zone. During the Saguenay earthquake 1988, one of the anchorage plates of the bridge supports failed. Herein, several configurations of seismic isolation system were considered to identify an appropriate solution for the seismic retrofitting of the bridge in both the longitudinal and transverse directions. A three-dimensional model of the bridge was created, and its seismic behavior studied through nonlinear dynamic time-history analysis. The comparative performance study among the five retrofitting configurations showed that the partial seismic isolation of the bridge led to an enhancement of the seismic response of the bridge in one direction only. However, the overall seismic response of the cable-stayed bridge substantially improved in the longitudinal and transverse directions in cases where the isolation systems were utilized between the supports and the deck-tower connection of the bridge.
    Matched MeSH terms: Steel*
  8. Agi A, Junin R, Rasol M, Gbadamosi A, Gunaji R
    PLoS One, 2018;13(8):e0200595.
    PMID: 30089104 DOI: 10.1371/journal.pone.0200595
    Treated Rhizopora mucronata tannin (RMT) as a corrosion inhibitor for carbon steel and copper in oil and gas facilities was investigated. Corrosion rate of carbon-steel and copper in 3wt% NaCl solution by RMT was studied using chemical (weight loss method) and spectroscopic (FTIR) techniques at various temperatures in the ranges of 26-90°C. The weight loss data was compared to the electrochemical by the application of Faraday's law for the conversion of corrosion rate data from one system to another. The inhibitive efficiency of RMT was compared with commercial inhibitor sodium benzotriazole (BTA-S). The best concentration of RMT was 20% (w/v), increase in concentration of RMT decreased the corrosion rate and increased the inhibitive efficiency. Increase in temperature increased the corrosion rate and decreased the inhibitive efficiency but, the rate of corrosion was mild with RMT. The FTIR result shows the presence of hydroxyl group, aromatic group, esters and the substituted benzene group indicating the purity of the tannin. The trend of RMT was similar to that of BTA-S, but its inhibitive efficiency for carbon-steel was poor (6%) compared to RMT (59%). BTA-S was efficient for copper (76%) compared to RMT (74%) at 40% (w/v) and 20% (w/v) concentration respectively. RMT was efficient even at low concentration therefore, the use of RMT as a cost effective and environmentally friendly corrosion inhibiting agent for carbon steel and copper is herein proposed.
    Matched MeSH terms: Steel/chemistry
  9. Nurul Atikah Shariff, Azman Jalar, Muhamad Izhar Sahri, Norinsan Kamil Othman
    Sains Malaysiana, 2014;43:1069-1075.
    Austenitic stainless steels of grade 304 were exposed to dry (Ar-75%CO2) and wet (Ar-75%CO2-12%H2O) environments at 700oC. This experimental setup involved horizontal tube furnace connected to CO2 gas and water vapour facilities. X-ray diffraction (XRD) technique, variable pressure-scanning electron microscope (VP-SEM) and optical microscope techniques were used to characterize the products of corrosion. The results of XRD showed that the phase of oxide layers consists of Cr2O3 and NiCr2O4 in dry CO2, meanwhile Fe2O3, Cr2O3, Fe0.56Ni0.34, Fe3O4 were identified in wet condition after 50 h. Adding 12%H2O in Ar-75%CO2 leads significantly in weight change occurred at 10 h exposure. However, after 20 h, the weight gain was decreased due to spallation of the oxide scale. The addition of water vapour accelerates the oxidation rate on the steel than that in dry condition. Morphologies and growth kinetics of these oxides vary with reaction condition. The oxidation behaviour at different times of exposure and the effect of water vapour were discussed in correlation with the microstructure of the oxides.
    Matched MeSH terms: Stainless Steel; Steel
  10. Lee HS, Park JH, Singh JK, Ismail MA
    Materials (Basel), 2016 Sep 03;9(9).
    PMID: 28773875 DOI: 10.3390/ma9090753
    Waste water treatment reservoirs are contaminated with many hazardous chemicals and acids. Reservoirs typically comprise concrete and reinforcement steel bars, and the main elements responsible for their deterioration are hazardous chemicals, acids, and ozone. Currently, a variety of techniques are being used to protect reservoirs from exposure to these elements. The most widely used techniques are stainless steel plating and polymeric coating. In this study, a technique known as arc thermal spraying was used. It is a more convenient and economical method for protecting both concrete and reinforcement steel bar from deterioration in waste water treatment reservoirs. In this study, 316L stainless steel coating was applied to a concrete surface, and different electrochemical experiments were performed to evaluate the performance of coatings in different acidic pH solutions. The coating generated from the arc thermal spraying process significantly protected the concrete surface from corrosion in acidic pH solutions, owing to the formation of a double layer capacitance-a mixture of Cr3+ enriched with Cr₂O₃ and Cr-hydroxide in inner and Fe3+ oxide on the outer layer of the coating. The formation of this passive film is defective owing to the non-homogeneous 316L stainless steel coating surface. In the pH 5 solution, the growth of a passive film is adequate due to the presence of un-dissociated water molecules in the aqueous sulfuric acid solution. The coated surface is sealed with alkyl epoxide, which acts as a barrier against the penetration of acidic solutions. This coating exhibits higher impedance values among the three studied acidic pH solutions.
    Matched MeSH terms: Stainless Steel; Steel
  11. Wan Dagang WR, Bowen J, O'Keeffe J, Robbins PT, Zhang Z
    Biotechnol Lett, 2016 May;38(5):787-92.
    PMID: 26892223 DOI: 10.1007/s10529-016-2047-x
    The adhesion of colloidal probes of stainless steel, glass and cellulose to Pseudomonas fluorescens biofilms was examined using atomic force microscopy (AFM) to allow comparisons between surfaces to which biofilms might adhere.
    Matched MeSH terms: Stainless Steel
  12. Ebenezer Akin Oluwasola, Md. Maniruzzaman A. Aziz, Naquiddin M. Warid M, Mohd Rosli Hainin
    Sains Malaysiana, 2016;45:278-287.
    This study focuses on the potential of electric arc furnace (EAF) steel slag and copper mine tailings as asphalt paving materials with respect to issues of volumetric properties and leaching. In this study, four different asphalt mixes were investigated; each contained EAF steel slag and copper mine tailings of various proportions. Apart from the microstructure analysis of the materials, a toxicity characteristics leaching procedure (TCLP) test was conducted on both the mixes and the aggregates. All the mixes were evaluated by the following parameters: Voids in the mineral aggregates (VMA), voids in total mix (VTM), voids filled with asphalt (VFA), Marshall stability and flow and specific gravity. F-test ANNOVA was used to evaluate the degree of significance of the mixes with each of the evaluated standards. It was observed that the mixes containing either EAF steel slag or copper mine tailings or both gave better results than the control mix. In terms of the TCLP test, none of the detected hazardous elements exceeded the standard limits, which indicates the possibility of using them as construction materials.
    Matched MeSH terms: Steel
  13. Mohd Zambri M.M., Wan Nurazreena W.H.
    Ann Dent, 2018;25(1):1-10.
    MyJurnal
    This report aimed to describe an effective biomechanics to control the upper incisors inclination during the
    correction of gummy smile with bimaxillary proclinations. A 14-year-old female presented with a Class II
    division I incisor relationship complicated with bimaxillary proclination on a Class 2 skeletal base. The lips
    were incompetent, showing 7 mm of upper incisors at rest and 5mm maxillary gingival display on smiling
    with normal upper lip length. Treatment involved extraction of all first permanent premolars followed by
    upper and lower fixed appliances. Intrusion of the upper incisors with controlled labial crown torque was
    accomplished with mini-implant anchorage placed bilaterally on the infrazygomatic crests with the retraction
    forces above the centre of resistance using 0.019x0.025-in stainless steel archwire in 0.022-in slot. The
    0.019x0.025-in stainless steel archwire in 0.022-in slot provided the vertical play to favour lingual crown
    tipping despite having forces above the centre of resistance for concurrent anterior segment intrusion.
    Matched MeSH terms: Stainless Steel
  14. Ahad Javanmardi, Zainab Ibrahim, Khaled Gheadi, Mohammed Jameel, Usman Hanif, Gordan, Meisam
    Scientific Research Journal, 2018;15(1):1-14.
    MyJurnal
    Nowadays, development of cable-stayed bridges is increasing around the world. The mitigation of seismic forces to these bridges are obligatory to prevent damages or failure of its structural members. Herein, this paper aimed to determine the near-fault ground motion effect on an existing cablestayed bridge equipped with lead-rubber bearing. In this context, Shipshaw cable-stayed bridge is selected as the case study. The selected bridge has a span of 183.2 m composite deck and 43 m height of steel tower. 2D finite element models of the non-isolated and base isolated bridges are modelled by using SAP2000. Three different near-fault ground motions which are Tabas 1978, Cape Mendocino 1992 and Kobe 1995 were subjected to the 2D FEM models in order to determine the seismic behaviour of the bridge. The near-fault ground motions were applied to the bridge in the longitudinal direction. Nonlinear dynamic analysis was performed to determine the dynamic responses of the bridge. Comparison of dynamic response of nonisolated and base isolated bridge under three different near-fault ground motions were conducted. The results obtained from numerical analyses of the bridge showed that the isolation system lengthened the period of bridge and minimised deck displacement, base shear and base moment of the bridge. It is concluded that the isolation system significantly reduced the destructive effects of near-fault ground motions on the bridge.
    Matched MeSH terms: Steel
  15. Soomro IA, Pedapati SR, Awang M
    Materials (Basel), 2021 Feb 08;14(4).
    PMID: 33567606 DOI: 10.3390/ma14040802
    Resistance spot welding (RSW) of dual phase (DP) steels is a challenging task due to formation of brittle martensitic structure in the fusion zone (FZ), resulting in a low energy capacity of the joint during high-rate loading. In the present study, in situ postweld heat treatment (PWHT) was carried out by employing a double pulse welding scheme with the aim of improving the mechanical performance of DP590 steel resistance spot weld joint. Taguchi method was used to optimize in situ PWHT parameters to obtain maximum peak load and failure energy. Experiments were designed based on orthogonal array (OA) L16. Mechanical performance was evaluated in terms of peak load and failure energy after performing low dynamic tensile shear (TS) test. Microstructural characterization was carried out using a scanning electron microscope (SEM). The results show that improvements of 17 and 86% in peak load and failure energy, respectively, were achieved in double-pulse welding (DPW) at optimum conditions compared to traditional single-pulse welding (SPW). The improvement in mechanical performance resulted from (i) enlargement of the FZ and (ii) improved weld toughness due to tempering of martensite in the FZ and subcritical heat affected zone (SCHAZ). These factors are influenced by heat input, which in turn depends upon in situ PWHT parameters.
    Matched MeSH terms: Steel
  16. Amer AAR, Abdullah MMAB, Liew YM, A Aziz IH, Wysłocki JJ, Tahir MFM, et al.
    Materials (Basel), 2021 Feb 26;14(5).
    PMID: 33652863 DOI: 10.3390/ma14051094
    The demand for durable, resistant, and high-strength structural material has led to the use of fibers as reinforcing elements. This paper presents an investigation into the inclusion of chopped steel wool fibers (CSWFs) in cement to form a high-flexural strength cementitious composite matrix (CCM). CSWFs were used as the primary reinforcement in CCM at increments of 0.5 wt%, from 0.5-6 wt%, with ratios of cement to sand of 1:1.5 and water to cement of 0.45. The inclusion of CSWFs resulted in an excellent optimization of the physicomechanical properties of the CCM, such as its density (2.302 g/cm3), compressive strength (61.452 MPa), and maximum flexural strength (10.64 MPa), all of which exceeded the performances of other reinforcement elements reported in the literature.
    Matched MeSH terms: Steel
  17. Ghazali MF, Abdullah MMAB, Abd Rahim SZ, Gondro J, Pietrusiewicz P, Garus S, et al.
    Materials (Basel), 2021 Mar 26;14(7).
    PMID: 33810517 DOI: 10.3390/ma14071628
    This paper reports on the potential use of geopolymer in the drilling process, with respect to tool wear and surface roughness. The objectives of this research are to analyze the tool life of three different economy-grade drill bit uncoated; high-speed steel (HSS), HSS coated with TiN (HSS-TiN), and HSS-cobalt (HSS-Co) in the drilling of geopolymer and to investigate the effect of spindle speed towards the tool life and surface roughness. It was found that, based on the range of parameters set in this experiment, the spindle speed is directly proportional to the tool wear and inversely proportional to surface roughness. It was also observed that HSS-Co produced the lowest value of surface roughness compared to HSS-TiN and uncoated HSS and therefore is the most favorable tool to be used for drilling the material. For HSS, HSS coated with TiN, and HSS-Co, only the drilling with the spindle speed of 100 rpm was able to drill 15 holes without surpassing the maximum tool wear of 0.10 mm. HSS-Co exhibits the greatest tool life by showing the lowest value of flank wear and produce a better surface finish to the sample by a low value of surface roughness value (Ra). This finding explains that geopolymer is possible to be drilled, and therefore, ranges of cutting tools and parameters suggested can be a guideline for researchers and manufacturers to drill geopolymer for further applications.
    Matched MeSH terms: Steel
  18. Mohamad Zaky Noh, Luay Bakir Hussain, Zainal Arifin Ahmad
    MyJurnal
    The joining of ceramic-metal could be done through a few techniques: brazing, diffusion bonding, friction welding etc. However, the mechanism of ceramic-metal joining was still not properly understood. In this study, alumina rod was bonded to mild steel rod via friction welding technique by using Al 1100 sheet as interlayer. The diameter of the rods was 10 mm. Friction pressure of 20 MPa and forging pressure of 40 MPa were used. Rotational speeds were maintained at 900 rpm and friction times of 2 to 20 seconds were applied. The joining strength was determined through four point bending test. The maximum bending strength, 240 MPa was obtained at the friction times of 20 seconds. Under optical microscope and SEM observation, the deformation of the aluminum interface was clearly obtained. Mechanical interlocking and close contact between the aluminaaluminum and aluminum-mild steel were observed at magnifications of 3000X. The strength of alumina-steel bonding is much dependent on the wettability of the alumina surface by the molten aluminum and the existing of mechanical interlocking between interlayer and sample materials.
    Matched MeSH terms: Steel
  19. Lopez JM, Sachithanandan A, Leow MP
    Med J Malaysia, 2016 Jun;71(3):142-3.
    PMID: 27495890 MyJurnal
    Hypersensitivity to stainless steel sternal sutures are an uncommon occurrence. We present a case of such a patient who developed chronic tissue overgranulation over a sternotomy wound eight weeks post-operatively. Primary suspicion was infection, a more common complication however radiological and laboratory investigation showed otherwise. Conservative management provided limited ephemeral success. After ensuring adequate sternal bone healing, the sutures and granulation tissue were eventually surgically removed without complication and the reoperated wound healed well.
    Matched MeSH terms: Steel
  20. Luo D, Li P, Yue Y, Ma J, Yang H
    Sensors (Basel), 2017 May 04;17(5).
    PMID: 28471372 DOI: 10.3390/s17050962
    The protection of concrete structures against corrosion in marine environments has always been a challenge due to the presence of a saline solution-A natural corrosive agent to the concrete paste and steel reinforcements. The concentration of salt is a key parameter influencing the rate of corrosion. In this paper, we propose an optical fiber-based salinity sensor based on bundled multimode plastic optical fiber (POF) as a sensor probe and a concave mirror as a reflector in conjunction with an intensity modulation technique. A refractive index (RI) sensing approach is analytically investigated and the findings are in agreement with the experimental results. A maximum sensitivity of 14,847.486/RIU can be achieved at RI = 1.3525. The proposed technique is suitable for in situ measurement and monitoring of salinity in liquid.
    Matched MeSH terms: Steel
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