Displaying publications 21 - 40 of 139 in total

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  1. Abazari S, Shamsipur A, Bakhsheshi-Rad HR, Ismail AF, Sharif S, Razzaghi M, et al.
    Materials (Basel), 2020 Oct 04;13(19).
    PMID: 33020427 DOI: 10.3390/ma13194421
    In recent years considerable attention has been attracted to magnesium because of its light weight, high specific strength, and ease of recycling. Because of the growing demand for lightweight materials in aerospace, medical and automotive industries, magnesium-based metal matrix nanocomposites (MMNCs) reinforced with ceramic nanometer-sized particles, graphene nanoplatelets (GNPs) or carbon nanotubes (CNTs) were developed. CNTs have excellent material characteristics like low density, high tensile strength, high ratio of surface-to-volume, and high thermal conductivity that makes them attractive to use as reinforcements to fabricate high-performance, and high-strength metal-matrix composites (MMCs). Reinforcing magnesium (Mg) using small amounts of CNTs can improve the mechanical and physical properties in the fabricated lightweight and high-performance nanocomposite. Nevertheless, the incorporation of CNTs into a Mg-based matrix faces some challenges, and a uniform distribution is dependent on the parameters of the fabricating process. The characteristics of a CNTs reinforced composite are related to the uniform distribution, weight percent, and length of the CNTs, as well as the interfacial bonding and alignment between CNTs reinforcement and the Mg-based matrix. In this review article, the recent findings in the fabricating methods, characterization of the composite's properties, and application of Mg-based composites reinforced with CNTs are studied. These include the strategies of fabricating CNT-reinforced Mg-based composites, mechanical responses, and corrosion behaviors. The present review aims to investigate and conclude the most relevant studies conducted in the field of Mg/CNTs composites. Strategies to conquer complicated challenges are suggested and potential fields of Mg/CNTs composites as upcoming structural material regarding functional requirements in aerospace, medical and automotive industries are particularly presented.
    Matched MeSH terms: Ceramics
  2. Yusof Abdullah, Mohd Reusmaazran Yusof, Azali Muhamad, Zaifol Samsu, Nurhaslinda Ee Abdullah
    MyJurnal
    Boron carbide (B4C) is a ceramic material which is effective to absorb thermal neutron due to wide neutron absorption cross section. In this work, B4C is added into concrete as fine aggregates to test the attenuation properties by getting the attenuation coefficient of the concrete/B4C. The samples of concrete/B4C were exposing to the thermal neutron radiation source (241-Americium-Berylium) at the dos rate of 29.08 mR/h. The result show that the attenuation coefficient of the sample with 20wt% B4C is 0.299cm -1 and the sample without B4C is 0.238cm -1 and hence, concrete/B4C is suitable as a shield for thermal neutron radiation.
    Matched MeSH terms: Ceramics
  3. Banjuraizah Johar, Hasmaliza Mohamad, Zainal Arifin Ahmad
    MyJurnal
    α Cordierite is very important phase in MgO-Al2O3-SiO2 system because of their very outstanding thermal, chemical and electrical properties. In this presents study nonstoichiometry cordierite (MgO:Al2O3:SiO2 = 3:1.5:5) using 2 different initial raw materials ( (i)mixture of pure oxide, and ii) mainly mixture of minerals) were fabricated and compared in terms of phase transformation and physical properties. Cordierite was prepared by glass method at low melting temperature (1350°C). Low melting temperature has resulted in partly crystalline glass which has possesses higher hardness, required longer milling time and result in contamination from grinding media. However, α-cordierite has successfully crystallized and fully densified at 850°C/2h. Activation energy for densification was investigated from thermal expansion coefficient (TCE) results. Other properties that were discussed included thermal properties using DTA/TGA.
    Matched MeSH terms: Ceramics
  4. Sandu AV, Vasilache V, Sandu IG, Sieliechi JM, Kouame IK, Matasaru PD, et al.
    Materials (Basel), 2019 Nov 21;12(23).
    PMID: 31766445 DOI: 10.3390/ma12233836
    The paper presents the results of ample investigations performed on industrial and traditional ceramics of fired clay used in processes of water potabilization in the last stage of filtration, after that of active charcoal. Using the data obtained through the scanning electron microscope coupled with energy dispersive X-ray analysis (SEM-EDX) and pH analyses, on the basis of the atomic composition and free concentration of hydronium ions, the normal caustic (Si/Al) and summative [(Si+Ti+FeIII+Cl)/(Al+Ca+Mg+Na+K)] modules were assessed, which were correlated with the free acidity and, respectively, the capacity of absorption and ionic exchange of the Fe3+ and Al3+ ions. The study allowed the selection, on the basis of the caustic module, of the ceramics with high capacity for ionic exchange.
    Matched MeSH terms: Ceramics
  5. Ahsan MR, Islam MT, Habib Ullah M, Mahadi WN, Latef TA
    ScientificWorldJournal, 2014;2014:909854.
    PMID: 25165750 DOI: 10.1155/2014/909854
    This paper presents a compact sized inset-fed rectangular microstrip patch antenna embedded with double-P slots. The proposed antenna has been designed and fabricated on ceramic-PTFE composite material substrate of high dielectric constant value. The measurement results from the fabricated prototype of the antenna show -10 dB reflection coefficient bandwidths of 200 MHz and 300 MHz with center resonant frequency of 1.5 GHz and 4 GHz, respectively. The fabricated antenna has attained gains of 3.52 dBi with 81% radiation efficiency and 5.72 dBi with 87% radiation efficiency for lower band and upper band, respectively. The measured E- and H-plane radiation patterns are also presented for better understanding. Good agreement between the simulation and measurement results and consistent radiation patterns make the proposed antenna suitable for GPS and C-band applications.
    Matched MeSH terms: Ceramics/chemistry*
  6. Pohchi A, Suzina AH, Samsudin AR, Al-Salihi KA
    Med J Malaysia, 2004 May;59 Suppl B:151-2.
    PMID: 15468863
    This in vivo study revealed that porous hydroxyapatite (PHA) and dense hydroxyapatite (DHA) are good implant materials that can accelerate bone healing and resorbed in acceptable time. But there were differences in the mechanism of the resorption of DHA and PHA due to variability in the physical properties and osteogenicity.
    Matched MeSH terms: Ceramics/analysis*
  7. Hisham NAN, Zaid MHM, Aziz SHA, Muhammad FD
    Materials (Basel), 2021 Jan 26;14(3).
    PMID: 33530370 DOI: 10.3390/ma14030570
    Soda lime silica (SLS) waste as the source of silica (SiO2) and ark clamshell (ACS) as the foaming agent has been utilized to fabricate the low-cost and lightweight foam glass-ceramics. A series of 1 and 6 wt% foam glass-ceramics were successfully prepared by the conventional solid-state sintering method at various sintering temperatures for 60 min. The bulk density of the samples has achieved minimum density (1.014 g/cm3) with maximum expansion (62.31%) at 6 wt% of the ACS content sintered at 800 °C for 60 min. The bulk density increases while the linear shrinkage and total porosity decrease with the progression of ACS contents and sintering temperature, where the results correspond with the FESEM micrograph. The result of XRD and FTIR transmittance spectra have shown that the formation of wollastonite crystal has occurred starting at 6 wt% of the ACS content sintered at 800 °C for 30 min. The highest mechanical performance (3.90 MPa) with an average total porosity (8.04%) is observed for the sample containing 1 wt% of ACS. It can be concluded that the composition of foam glass-ceramics (1 and 6 wt%) and sintering temperatures give significant results to the structural, physical, and mechanical properties of the fabricated foam glass-ceramics.
    Matched MeSH terms: Ceramics
  8. Ang Y, Tew IM
    J Conserv Dent, 2021 02 11;23(6):644-647.
    PMID: 34083924 DOI: 10.4103/JCD.JCD_533_20
    Restoring extensively damaged endodontically treated posterior teeth is always a challenge in dentistry. The use of endocrowns has gained popularity in restoring severely damaged endodontically treated teeth (ETT) in recent years. In this clinical report, a structurally compromised mandibular second molar with symptomatic irreversible pulpitis and normal apical tissue was endodontically treated. Surgical crown lengthening was attempted thereafter to increase the crown height. However, marginal periodontal tissue re-growth occurred after surgical crown lengthening. The tooth was subsequently restored with endocrown which was fabricated using computer-aided design and computer-aided manufacturing-based hybrid-ceramic. In conclusion, endocrown can be a viable restorative modality for ETT with compromised clinical crown height.
    Matched MeSH terms: Ceramics
  9. 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: Ceramics
  10. Hashim SM, Mohamed AR, Bhatia S
    Adv Colloid Interface Sci, 2010 Oct 15;160(1-2):88-100.
    PMID: 20813344 DOI: 10.1016/j.cis.2010.07.007
    There has been tremendous progress in membrane technology for gas separation, in particular oxygen separation from air in the last 20 years. It provides an alternative route to the existing conventional separation processes such as cryogenic distillation and pressure swing adsorption as well as cheaper production of oxygen with high purity. This review presents the recent advances of ceramic membranes for the separation of oxygen from air at high temperature. It covers the issues and problems with respect to the selectivity and separation performance. The paper also presents different approaches applied to overcome these challenges. The future directions of ceramic-based membranes for oxygen separation from air are also presented.
    Matched MeSH terms: Ceramics/chemistry*
  11. Okolo C, Rafique R, Iqbal SS, Subhani T, Saharudin MS, Bhat BR, et al.
    Molecules, 2019 Sep 01;24(17).
    PMID: 31480573 DOI: 10.3390/molecules24173176
    A novel tweakable nanocomposite was prepared by spark plasma sintering followed by systematic oxidation of carbon nanotube (CNT) molecules to produce alumina/carbon nanotube nanocomposites with surface porosities. The mechanical properties (flexural strength and fracture toughness), surface area, and electrical conductivities were characterized and compared. The nanocomposites were extensively analyzed by field emission scanning electron microscopy (FE-SEM) for 2D qualitative surface morphological analysis. Adding CNTs in ceramic matrices and then systematically oxidizing them, without substantial reduction in densification, induces significant capability to achieve desirable/application oriented balance between mechanical, electrical, and catalytic properties of these ceramic nanocomposites. This novel strategy, upon further development, opens new level of opportunities for real-world/industrial applications of these relatively novel engineering materials.
    Matched MeSH terms: Ceramics/chemistry*
  12. Hassan U, Farooq I, Moheet IA, AlShwaimi E
    Int J Health Sci (Qassim), 2017 Sep-Oct;11(4):23-27.
    PMID: 29085264
    OBJECTIVES: The aim of the present study was to test cutting efficiency of different materials against conventional alumina in an air abrasion system.

    MATERIALS AND METHODS: The powder samples were divided into three groups: Group 1 - alumina (control), Group 2 - 45S5 bioactive glass, and Group 3 - hydroxyapatite. 30 microscope glass slides of 0.5 mm thickness were used as an alternative of human enamel and were also divided randomly into these three groups. The time taken by the abrasive particles to cut a hole through the microscope glass slide was recorded with a stop watch. In addition, morphology of the particles was observed through scanning electron microscopy (SEM). A t-test was used to compare the times taken to cut a hole through the microscope glass slides, and the level of significance was set at P < 0.05.

    RESULTS: The mean time taken to cut a hole through the microscope glass slide was 2.96 s and 23.01s for Groups 1 and 2, respectively, whereas powder of Group 3 did not cut after 120 s. The differences between cutting times of Groups 1 and 2 were statistically significant (P < 0.05). The SEM micrographs revealed coarse angular shape for particles of Groups 1 and 2 but Group 3 particles were with round ends and presence of smaller particles was also observed in Groups 2 and 3.

    CONCLUSION: The alumina particles demonstrated excellent cutting efficiency followed by 45S5 particles. The use of bioactive glass particles should be encouraged for cutting purposes whenever a shortage of time for practitioners is not a concern.
    Matched MeSH terms: Ceramics
  13. Munusamy SM, Helen-Ng LC, Farook MS
    BMC Oral Health, 2024 Feb 01;24(1):162.
    PMID: 38302972 DOI: 10.1186/s12903-024-03905-7
    BACKGROUND: Computer-aided design/computer-aided manufacturing (CAD/CAM) dental composites were introduced with superior mechanical properties than conventional dental composites. However, little is known on effects of dietary solvents on microhardness or inorganic elemental composition of CAD/CAM composites.

    OBJECTIVES: The objectives of this study were to evaluate the degradation effects of each dietary solvent on the microhardness of the different CAD/CAM dental composites and to observe the degradation effects of dietary solvent on the inorganic elements of the dental composites investigated.

    METHODS: Fifty specimens with dimensions 12 mm x 14 mm x 1.5 mm were prepared for direct composite (Filtek Z350 XT [FZ]), indirect composite (Shofu Ceramage [CM]), and three CAD/CAM composites (Lava Ultimate [LU], Cerasmart [CS], and Vita Enamic [VE]). The specimens were randomly divided into 5 groups (n = 10) and conditioned for 1-week at 37°C in the following: air (control), distilled water, 0.02 N citric acid, 0.02 N lactic acid and 50% ethanol-water solution. Subsequently, the specimens were subjected to microhardness test (KHN) using Knoop hardness indenter. Air (control) and representative postconditioning specimens with the lowest mean KHN value for each material were analyzed using energy dispersive X-ray spectroscopy (EDX). Statistical analysis was done using one-way ANOVA and post hoc Bonferroni test at a significance level of p = 0.05.

    RESULTS: Mean KHN values ranged from 39.7 ± 2.7 kg/mm2 for FZ conditioned in 50% ethanol-water solution to 79.2 ± 3.4 kg/mm2 for VE conditioned in air (control). With exception to LU, significant differences were observed between materials and dietary solvents for other dental composites investigated. EDX showed stable peaks of the inorganic elements between air (control) and representative postconditioning specimens.

    CONCLUSIONS: The microhardness of dental composites was significantly affected by dietary solvents, except for one CAD/CAM composite [LU]. However, no changes were observed in the inorganic elemental composition of dental composites between air (control) and 1-week postconditioning.

    Matched MeSH terms: Ceramics*
  14. Tripathy A, Pramanik S, Manna A, Bhuyan S, Azrin Shah NF, Radzi Z, et al.
    Sensors (Basel), 2016 Jul 21;16(7).
    PMID: 27455263 DOI: 10.3390/s16071135
    Despite the many attractive potential uses of ceramic materials as humidity sensors, some unavoidable drawbacks, including toxicity, poor biocompatibility, long response and recovery times, low sensitivity and high hysteresis have stymied the use of these materials in advanced applications. Therefore, in present investigation, we developed a capacitive humidity sensor using lead-free Ca,Mg,Fe,Ti-Oxide (CMFTO)-based electro-ceramics with perovskite structures synthesized by solid-state step-sintering. This technique helps maintain the submicron size porous morphology of the developed lead-free CMFTO electro-ceramics while providing enhanced water physisorption behaviour. In comparison with conventional capacitive humidity sensors, the presented CMFTO-based humidity sensor shows a high sensitivity of up to 3000% compared to other materials, even at lower signal frequency. The best also shows a rapid response (14.5 s) and recovery (34.27 s), and very low hysteresis (3.2%) in a 33%-95% relative humidity range which are much lower values than those of existing conventional sensors. Therefore, CMFTO nano-electro-ceramics appear to be very promising materials for fabricating high-performance capacitive humidity sensors.
    Matched MeSH terms: Ceramics
  15. Li T, Heenan TMM, Rabuni MF, Wang B, Farandos NM, Kelsall GH, et al.
    Nat Commun, 2019 04 02;10(1):1497.
    PMID: 30940801 DOI: 10.1038/s41467-019-09427-z
    Ceramic fuel cells offer a clean and efficient means of producing electricity through a variety of fuels. However, miniaturization of cell dimensions for portable device application remains a challenge, as volumetric power densities generated by readily-available planar/tubular ceramic cells are limited. Here, we demonstrate a concept of 'micro-monolithic' ceramic cell design. The mechanical robustness and structural integrity of this design is thoroughly investigated with real-time, synchrotron X-ray diffraction computed tomography, suggesting excellent thermal cycling stability. The successful miniaturization results in an exceptional power density of 1.27 W cm-2 at 800 °C, which is among the highest reported. This holistic design incorporates both mechanical integrity and electrochemical performance, leading to mechanical property enhancement and representing an important step toward commercial development of portable ceramic devices with high volumetric power (>10 W cm-3), fast thermal cycling and marked mechanical reliability.
    Matched MeSH terms: Ceramics
  16. Affa Rozana Abdul Rashid, Nur Insyierah Md Sarif, Khadijah Ismail
    MyJurnal
    The consumption of low-power electronic devices has increased rapidly, where almost all applications use power electronic devices. Due to the increase in portable electronic devices’ energy consumption, the piezoelectric material is proposed as one of the alternatives of the significant alternative energy harvesters. This study aims to create a prototype of “Smart Shoes” that can generate electricity using three different designs embedded by piezoelectric materials: ceramic, polymer, and a combination of both piezoelectric materials. The basic principle for smart shoes’ prototype is based on the pressure produced from piezoelectric material converted from mechanical energy into electrical energy. The piezoelectric material was placed into the shoes’ sole, and the energy produced due to the pressure from walking, jogging, and jumping was measured. The energy generated was stored in a capacitor as piezoelectric material produced a small scale of energy harvesting. The highest energy generated was produced by ceramic piezoelectric material under jumping activity, which was 1.804 mJ. Polymer piezoelectric material produced very minimal energy, which was 55.618 mJ. The combination of both piezoelectric materials produced energy, which was 1.805 mJ from jumping activity.

    Matched MeSH terms: Ceramics
  17. Siew PF, Wan Yusmawati Wan Yusoff, Azman Jalar
    Sains Malaysiana, 2014;43:827-832.
    The physical properties and structural stability of the Quad Flat No-Leads (QFN) package with different gamma radiation doses have been investigated. The packages were irradiated with Co-60 gamma radiation with varying doses of 5 Gy, 50 Gy, 500 Gy, 5 kGy and 50 kGy with operating dose of 2.54 kGylh at room temperature. The infinite focus microscope (IFM) was used to measure the dimensional change and slantinglwarpage behaviour, while the 3D CT Scan X-ray machine was used to determine the occurrence of deflection on a wire in package due to exposure. It is believed that radiation effect on ceramic filler in the epoxy mold compound (EMC) plays an important role to induce the defects and resulted in swelling of the package. The slantinglwarpage behaviour is believed to be caused by the swelling behaviour of ceramic filler and further induced structural stability. The induced stress on the EMC structural after the dimensional change and slantinglwarpage failure leads to the occurrence of wire sweep. The finding suggests that defect production in swelled ceramic filler leads to the occurrence of dimensional and structure instability.
    Matched MeSH terms: Ceramics
  18. Yahya, N.A., Lim, K.H.D.
    Ann Dent, 2008;15(2):89-93.
    MyJurnal
    Direct composite veneers can be used to mask tooth discolorations and/or to correct unaesthetic tooth forms and/or positions. However, these type of restorations are often regarded as one of the most challenging in aesthetic dentistry presumably due to the extent of natural tooth structure that must be recreated. This paper discusses easy application techniques and tips for Ceram.X Duo™, a nano ceramic composite restorative material. Its natural shading system allows the restoration of tooth with both dentine and enamel shade and transforms it into a final direct veneer restoration that mimics a natural tooth.
    Matched MeSH terms: Ceramics
  19. Hassan M, Yahya A, Okamoto T
    In this paper, we report the effect of BaAl2O4 addition (0-30 wt. %) on power consumption and oxygen sensing response of hot-spots developed on short Er123 ceramic rods of around 12 mm length synthesized using standard solid-state reaction. All the sensor rods showed increase in output current with increasing voltage followed by sudden reduction in output current and appearance of hot spot. After appearance of hot spot, for each rod, output current was observed to decrease gradually with increasing voltage with the slope of the I-V curve gradually approaching zero. Output current after the hot spot formation showed sensitivity to oxygen partial pressure, pO2 between 1 to 100 kPa. Addition of 30 wt. % BaAl2O4 reduced the fluctuation of current and increased the sensitivity for pO2 below 10 kPa. In addition, overshoot current was also reduced and resulted in improvement of response time from around 10 s to 5 s. Our result also showed that minimum power consumption was significantly reduced in the Er123 rods with 30 wt. % BaAl2O4.
    Matched MeSH terms: Ceramics
  20. Al-Makramani BMA, Razak AAA, Abu-Hassan MI, Al-Sanabani FA, Albakri FM
    Open Access Maced J Med Sci, 2018 Mar 15;6(3):548-553.
    PMID: 29610618 DOI: 10.3889/oamjms.2018.111
    BACKGROUND: The selection of the appropriate luting cement is a key factor for achieving a strong bond between prepared teeth and dental restorations.

    AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material.

    MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - μm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test.

    RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05).

    CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.

    Matched MeSH terms: Ceramics
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