Displaying publications 1 - 20 of 104 in total

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  1. [Ionic liquid based ultrasonication-assisted extraction of essential oil from the leaves of Persicaria minor and conductor-like screening model for realistic solvents study]
    Habib U, Cecilia DW, Maizatul SS
    Se Pu, 2017 Jun 08;35(6):656-664.
    PMID: 29048794 DOI: 10.3724/SP.J.1123.2017.02002
    Ionic liquids (ILs) based ultrasonic-assisted extract has been applied for the extraction of essential oil from Persicaria minor leaves. The effects of temperature, sonication time, and particle size of the plant material on the yield of essential oil were investigated. Among the different ILs employed, 1-ethyl-3-methylimidazolium acetate was the most effective, providing a 9.55% yield of the essential oil under optimum conditions (70 ℃, 25 min, IL:hexane ratio of 7:10 (v/v), particle size 60-80 mesh). The performance of 1-ethyl-3-methylimidazolium acetate in the extraction was attributed to its low viscosity and ability to disintegrate the structural matrix of the plant material. The ability of 1-ethyl-3-methylimidazolium acetate was also confirmed using the conductor like-screening model for realistic solvents. This research proves that ILs can be used to extract essential oils from lignocellulosic biomass.
    Matched MeSH terms: Ultrasonics
  2. Fulltext Zeolite RHO Synthesis Accelerated by Ultrasonic Irradiation Treatment
    Ng TYS, Chew TL, Yeong YF, Jawad ZA, Ho CD
    Sci Rep, 2019 10 21;9(1):15062.
    PMID: 31636339 DOI: 10.1038/s41598-019-51460-x
    In recent years, there are increasing interest on applying ultrasonic irradiation for the synthesis of zeolite due to its advantages including remarkable shortened synthesis duration. In this project, the potential of ultrasonic irradiation treatment on the synthesis of zeolite RHO was investigated. Ultrasonic irradiation treatment time was varied from 30 to 120 minutes for the synthesis of zeolite RHO. The zeolite RHO solid samples were characterized with X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and nitrogen adsorption-desorption analysis. The application of ultrasonic irradiation treatment in this study has accelerated the synthesis of zeolite RHO where the synthesis duration has been significantly shortened to 2 days compared to 8 days required by conventional hydrothermal heating without ultrasonic irradiation treatment. Highly crystalline zeolite RHO crystals in truncated octahedron morphology were successfully formed.
    Matched MeSH terms: Ultrasonics
  3. Fulltext Using a syringe needle to cut dentin and dislodge and remove a metallic obstruction from the root canal
    Vivekananda Pai AR, Arora V
    J Conserv Dent, 2018 4 21;21(2):230-232.
    PMID: 29674831 DOI: 10.4103/JCD.JCD_316_16
    A metallic obstruction in the canal orifice of a maxillary right canine could not be bypassed during endodontic treatment. Aids such as ultrasonics and retrieval kits were not available for the removal of the obstruction. Therefore, a novel approach using a disposable syringe needle was employed. A 22-gauge needle was inserted into the orifice and turned in an arc with a gentle apical pressure and alternate rocking motion around the obstruction. This procedure was repeated few times to cut dentin and successfully dislodge and remove the obstruction using the sharp beveled tip of the needle. This case report demonstrates that, in the absence of other aids, the use of a disposable syringe needle is a simple, economical, and yet an effective technique for conservative removal of dentin and to dislodge and remove an obstruction from the root canal. However, its effectiveness depends on case selection and straight-line accessibility to the obstruction.
    Matched MeSH terms: Ultrasonics
  4. Use of ultrasonic velocity travel time to estimate uniaxial compressive strength of granite and schist in Malaysia
    Abdul Ghani Rafek, Azimah Hussin, Lee KE, Ailie Sofyiana Serasa, Goh TL
    Sains Malaysiana, 2016;45:185-193.
    The uniaxial compressive strength (UCS) is one of the most common mechanical parameters required in geotechnical engineering to characterize the compressive strength of rock material. Measurements of UCS are expensive, time consuming, destructive and thus, not favorable in the presence of limited samples. Therefore, a simple yet practical application is needed for the estimation of UCS. This research presents two correlations to predict UCS values for granite and schist by using ultrasonic velocity travel time (tp) from ultrasonic tests. The validity of the practical approach presented in this research is confirmed based on the strong correlations developed from the experimental tests conducted. For the entire data set, the correlation between UCS and ultrasonic velocity travel time was expressed as UCS = 217.2 e-0.016(tp) for granite and UCS = 1110.6 e-0.037(tp) for schist and the coefficient of determination (R2) value for both granite and schist is 0.93. These correlations may be useful for applications related to geotechnical engineering designs.
    Matched MeSH terms: Ultrasonics
  5. Fulltext Ultrasound-assisted extraction of valuable compounds from winter melon (Benincasa hispida) seeds
    Bimakr, M., Rahman, R.A., Saleena Taip, F., Adzahan, N.M., Islam Sarker, Z., Ganjloo, A
    International Food Research Journal, 2013;20(1):331-338.
    MyJurnal
    Ultrasound-assisted extraction (UAE) was applied for the extraction of bioactive valuable compounds from winter melon (Benincasa hispida) seeds. Effects of amplitude (25-75%), temperature (40-60°C) and sonication time (20-60 min) on crude extraction yield (CEY) and radical scavenging activities (RSA, % inhibition of DPPH˙ and ABTS˙+ free radicals) of extracts were determined using complete randomised design (CRD). The results showed that the CEY and RSA of extracts significantly affected by independent variables. The maximum value of CEY (97.14±0.36 mgg-1), scavenging of DPPH˙ radicals (32.12 ± 0.38%) and scavenging of ABTS˙+ radicals (40.52±0.73%) were obtained at the combined treatment conditions of 75%, 55°C and 40 min. The UAE results obtained were compared with those achieved by using conventional Soxhlet extraction (CSE) method. It was found UAE allowed extraction at lower temperature and the extracts obtained posses higher quality compare with CSE. UAE is a promising environment friendly technique for the extraction of bioactive compounds from winter melon (Benincasa hispida) seeds.
    Matched MeSH terms: Ultrasonics
  6. Fulltext Ultrasound-assisted encapsulation of Pandan (Pandanus amaryllifolius) extract
    Omer N, Choo YM, Ahmad N, Mohd Yusof NS
    Ultrason Sonochem, 2021 Nov;79:105793.
    PMID: 34673338 DOI: 10.1016/j.ultsonch.2021.105793
    Pandan (Pandanus amaryllifolius) is commonly used as a food ingredient in Southeast Asia due to its delicious flavor, appetizing aroma and bright green colour. Pandan plant is uniquely found only in certain parts of the world. Despite its increasing popularity worldwide, its export market is limited by practical issues. One of the main problems for exporting Pandan to global market is its stability during transport. Due to the volatility of its active constituent, the functional properties of Pandan are lost during storage and shipment. In this study, we explored the ability of ultrasound processing technology to encapsulate the aromatic Pandan extract using lysozyme or chitosan as a shell material. 20 kHz ultrasonicator was used to encapsulate the pandan extract at 150 W of applied power. Two parameters, the ultrasonic probe tip and the core-to-shell ratio were varied to control the properties of the encapsulates. The diameters of the probe tip used were 0.3 and 1.0 cm. The core-to-shell volume ratios used were 1:160 and 1:40. The size distribution and the stability of the synthesized microspheres were characterized to understand and explore the possible parameters variation impact. Both size and size distribution of the microspheres were found to be influenced by the parameters varied to certain extent. The results showed that the mean size of the microspheres was generally smallest when using 1 cm probe tip with lower core-to-shell volume ratio but largest when using the 3 mm tip with higher core-to-shell volume ratio. This indicates that the sonication parameters could be fine-tuned to achieve the encapsulation of Pandan extract for storage and export. The pandan-encapsulated microspheres were also found to be stable during storage at least for one month.
    Matched MeSH terms: Ultrasonics
  7. Ultrasound enhanced growth and cholesterol removal of Lactobacillus fermentum FTDC 1311 in the parent cells but not the subsequent passages
    Lye HS, Khoo BY, Karim AA, Rusul G, Liong MT
    Ultrason Sonochem, 2012 Jul;19(4):901-8.
    PMID: 22265020 DOI: 10.1016/j.ultsonch.2011.12.018
    The aim of this study was to evaluate the effect of ultrasound on the intestinal adherence ability, cell growth, and cholesterol removal ability of parent cells and subsequent passages of Lactobacillus fermentum FTDC 1311. Ultrasound significantly decreased the intestinal adherence ability of treated parent cells compared to that of the control by 11.32% (P<0.05), which may be due to the protein denaturation upon local heating. Growth of treated parent cells also decreased by 4.45% (P<0.05) immediately upon ultrasound (0-4h) and showed an increase (P<0.05) in the viability by 2.18-2.34% during the later stage of fermentation (12-20 h) compared to that of the control. In addition, an increase (P<0.05) in assimilation of cholesterol (>9.74%) was also observed for treated parent cells compared to that of the control, accompanied by increased (P<0.05) incorporation of cholesterol into the cellular membrane. This was supported by the increased ratio of membrane cholesterol:phospholipids (C:P), saturation of cholesterol in the apolar regions, upper phospholipids regions, and polar regions of membrane phospholipids of parent cells compared to that of the control (P<0.05). However, such traits were not inherited by the subsequent passages of treated cells (first, second, and third passages). Our data suggested that ultrasound treatment could be used to improve cholesterol removal ability of parent cells without inducing permanent damage/defects on treated cells of subsequent passages.
    Matched MeSH terms: Ultrasonics*
  8. Ultrasonic-assisted glycosylation with κ-carrageenan on the functional and structural properties of fish gelatin
    Ding K, Geng H, Guo W, Sun W, Zhan S, Lou Q, et al.
    J Sci Food Agric, 2023 Aug 30;103(11):5322-5331.
    PMID: 37016806 DOI: 10.1002/jsfa.12600
    BACKGROUND: Fish gelatin (FG) has multifunctional properties similar to mammalian gelatin (MG), and it has been recognized as the optimal alternative to MG. While its poor surface-active and gelling properties significantly limit its application values, glycosylation has been successfully used to increase surface-active properties of FG, but the influence of ultrasonic-associated glycosylation (UAG) on the gelling and structural characteristics of FG is still rarely reported. This article explores UAG (100-200 W, 0.5-1 h) with κ-carrageenan (κC) on the functional properties (emulsifying, gelling and rheological properties) and structural characteristics of FG.

    RESULTS: The longer time and higher power of ultrasonics accelerated the glycosylation reaction with an increase in glycosylation degree and browning index values. Compared with original FG, FG-κC mixture and bovine gelatin, UAG-modified FG possessed higher emulsification activity index, emulsion stability index, gel strength, hardness and melting temperature values. Among them, gelatin modified by appropriate ultrasonic conditions (200 W, 0.5 h) had the highest emulsifying and gelling properties. Rheological results showed that UAG contributed to the gelation process of gelatin with advanced gelation time and endowed it with high viscosity. Structural analysis indicated that UAG promoted κC to link with FG by the formation of covalent and hydrogen bonds, restricting more bound and immobilized water in the gels, exhibiting higher gelling properties.

    CONCLUSION: This work showed that UAG with κC is a promising method to produce high gelling and emulsifying properties of FG that could replace MG. © 2023 Society of Chemical Industry.

    Matched MeSH terms: Ultrasonics*
  9. Fulltext Ultrasonic scissors-assisted 'open-book' thyroidectomy in massive goiter compressing airway and causing unilateral vocal cord paralysis
    Irfan M, Yaroko AA, Soleh MN, Periasamy C
    Med J Malaysia, 2013 Apr;68(2):183-5.
    PMID: 23629575
    A massive goiter may constrict the trachea resulting in shortness of breath. Recurrent laryngeal nerve compression may cause vocal cord paralysis. We highlight a case of a 62- year-old female with a 30 year history of an anterior neck swelling gradually increasing in size. She presented with acute symptoms of upper airway obstruction and voice changes. Emergency thyroidectomy was performed by dividing the middle part of the gland using ultrasonic scissors. The recovery was uneventful and the patient regained normal vocal cord function post operatively.
    Matched MeSH terms: Ultrasonics
  10. Fulltext Ultrasonic liquid exfoliation for producing graphene materials from rice stem: Investigating cellular components and functionalities
    Wu X, Sivakumar M, Lim SS, Wu T, Heng PC
    Ultrason Sonochem, 2024 Feb;103:106782.
    PMID: 38309050 DOI: 10.1016/j.ultsonch.2024.106782
    This study investigates a prospective and straightforward method for producing graphene material derived from biomass, examining the influence of plant cell composition and functions. The experimental outcomes highlight ultrasound's crucial role in synthesizing graphene material sourced from biomass. Ultrasound, a pivotal element in the experiment, significantly affects graphene production from biomass by working synergistically with the liquid components in the solvent system. Notably, the ethanol content reduces the solution's surface tension, facilitating the effective dispersion of biochar and graphene oxide sheets throughout the process. Simultaneously, the water content maintains the solution's polarity, enhancing the cavitation effect induced by ultrasound. Biomass-derived graphene is exfoliated utilizing an ultrasonic bath system (134.4 W, 40 kHz, 0.5 W/cm2) from biochar. The as-synthesized graphene oxide exhibits a structure comprising a few layers while remaining intact, featuring abundant functional groups. Interestingly, the resulting product displays nanopores with an approximate diameter of 100 nm. These nanopores are attributed to preserving specific cell structures, particularly those with specialized cell wall structures or secondary metabolite deposits from biomass resources. The study's findings shed light on the impact of cellular structure on synthesizing graphene material sourced from biomass, emphasizing the potential application of ultrasound as a promising approach in graphene production.
    Matched MeSH terms: Ultrasonics
  11. Ultrasonic extraction of anthocyanin from Clitoria ternatea flowers using response surface methodology
    Chong FC, Gwee XF
    Nat Prod Res, 2015;29(15):1485-7.
    PMID: 25836369 DOI: 10.1080/14786419.2015.1027892
    The ultrasonic extraction (UE) method of anthocyanin from Clitoria ternatea flowers using response surface methodology (RSM) was performed in this study. By using RSM, the objective is to optimise the extraction yield of anthocyanin from C. ternatea which is influenced by various factors, including the extraction temperature, time, ratio of solvent to solid and ultrasonic power. The empirical model was investigated by performing first-level optimisation in a two-level factorial design with Design Expert 7 software. In comparison with the conventional solvent extraction, UE showed a 246.48% better extraction yield and produced an anthocyanin extract with a radical scavenging activity of 68.48% at the optimised factors of 50°C, 150 min, 15 mL/g and 240 W.
    Matched MeSH terms: Ultrasonics/methods*
  12. Fulltext Ultrasonic cavitation: An effective cleaner and greener intensification technology in the extraction and surface modification of nanocellulose
    Hoo DY, Low ZL, Low DYS, Tang SY, Manickam S, Tan KW, et al.
    Ultrason Sonochem, 2022 Nov;90:106176.
    PMID: 36174272 DOI: 10.1016/j.ultsonch.2022.106176
    With rising consumer demand for natural products, a greener and cleaner technology, i.e., ultrasound-assisted extraction, has received immense attention given its effective and rapid isolation for nanocellulose compared to conventional methods. Nevertheless, the application of ultrasound on a commercial scale is limited due to the challenges associated with process optimization, high energy requirement, difficulty in equipment design and process scale-up, safety and regulatory issues. This review aims to narrow the research gap by placing the current research activities into perspectives and highlighting the diversified applications, significant roles, and potentials of ultrasound to ease future developments. In recent years, enhancements have been reported with ultrasound assistance, including a reduction in extraction duration, minimization of the reliance on harmful chemicals, and, most importantly, improved yield and properties of nanocellulose. An extensive review of the strengths and weaknesses of ultrasound-assisted treatments has also been considered. Essentially, the cavitation phenomena enhance the extraction efficiency through an increased mass transfer rate between the substrate and solvent due to the implosion of microbubbles. Optimization of process parameters such as ultrasonic intensity, duration, and frequency have indicated their significance for improved efficiency.
    Matched MeSH terms: Ultrasonics*
  13. Ultrasonic assisted ultrafiltration process for emulsification of oil field produced water treatment
    Agi A, Junin R, Alqatta AYM, Gbadamosi A, Yahya A, Abbas A
    Ultrason Sonochem, 2019 Mar;51:214-222.
    PMID: 30401623 DOI: 10.1016/j.ultsonch.2018.10.023
    Ultrafiltration has been proven to be very effective in the treatment of oil-in-water emulsions, since no chemical additives are required. However, ultrafiltration has its limitations, the main limits are concentration polarization resulting to permeate flux decline with time. Adsorption, accumulation of oil and particles on the membrane surface which causes fouling of the membrane. Studies have shown that the ultrasonic is effective in cleaning of fouled membrane and enhancing membrane filtration performance. But the effectiveness also, depends on the selection of appropriate membrane material, membrane geometry, ultrasonic module design, operational and processing condition. In this study, a hollow and flat-sheet polyurethane (PU) membranes synthesized with different additives and solvent were used and their performance evaluated with oil-in-water emulsion. The steady-state permeate flux and the rejection of oil in percentage (%) at two different modes were determined. A dry/wet spinning technique was used to fabricate the flat-sheet and hollow fibre membrane (HFMs) using Polyethersulfone (PES) polymer base, Polyvinylpyrrolidone (PVP) additive and N, N-Dimethylacetamide (DMAc) solvent. Ultrasonic assisted cross-flow ultrafiltration module was built to avoid loss of ultrasonic to the surrounding. The polyurethane (PU) was synthesized by polymerization and sulphonation to have an anionic group (-OH; -COOH; and -SO3H) on the membrane surface. Changes in morphological properties of the membrane had a significant effect on the permeate flow rate and oil removal. Generation of cavitation and Brownian motion by the ultrasonic were the dominant mechanisms responsible for ultrafiltration by cracking the cake layers and reducing concentration polarization at the membrane surface. The percentage of oil after ultrafiltration process with ultrasonic is about 90% compared to 49% without ultrasonic. Ultrasonic is effective in enhancing the membrane permeate flux and controlling membrane fouling.
    Matched MeSH terms: Ultrasonics
  14. Fulltext Ultrasonic Assisted Synthesis of Size-Controlled Cu-Metal-Organic Framework Decorated Graphene Oxide Composite: Sustainable Electrocatalyst for the Trace-Level Determination of Nitrite in Environmental Water Samples
    Arul P, Gowthaman NSK, John SA, Lim HN
    ACS Omega, 2020 Jun 23;5(24):14242-14253.
    PMID: 32596560 DOI: 10.1021/acsomega.9b03829
    Excess levels of nitrite ion in drinking water interact with amine functionalized compounds to form carcinogenic nitrosamines, which cause stomach cancer. Thus, it is indispensable to develop a simple protocol to detect nitrite. In this paper, a Cu-metal-organic framework (Cu-MOF) with graphene oxide (GO) composite was synthesized by ultrasonication followed by solvothermal method and then fabricated on a glassy carbon (GC) electrode for the sensitive and selective determination of nitrite contamination. The SEM image of the synthesized Cu-MOF showed colloidosome-like structure with an average size of 8 μm. Interestingly, the Cu-MOF-GO composite synthesized by ultrasonic irradiation followed by solvothermal process produce controlled size of 3 μm colloidosome-like structure. This was attributed to the formation of an exfoliated sheet-like structure of GO by ultrasonication in addition to the obvious influence of GO providing the oxygen functional groups as a nucleation node for size-controlled growth. On the other hand, the composite prepared without ultrasonication exhibited 6.6 μm size agglomerated colloidosome-like structures, indicating the crucial role of ultrasonication for the formation of size-controlled composites. XPS results confirmed the presence of Cu(II) in the as-synthesized Cu-MOF-GO based on the binding energies at 935.5 eV for Cu 2p3/2 and 955.4 eV for Cu 2p1/2. The electrochemical impedance studies in [Fe(CN)6]3-/4- redox couple at the composite fabricated electrode exhibited more facile electron transfer than that with Cu-MOF and GO modified electrodes, which helped to utilize Cu-MOF-GO for trace level determination of nitrite in environmental effluent samples. The Cu-MOF-GO fabricated electrode offered a superior sensitive platform for nitrite determination than the Cu-MOF and GO modified electrodes demonstrating oxidation at less positive potential with enhanced oxidation current. The present sensor detects nitrite in the concentration range of 1 × 10-8 to 1 × 10-4 M with the lowest limit of detection (LOD) of 1.47 nM (S/N = 3). Finally, the present Cu-MOF-GO electrode was successfully exploited for nitrite ion determination in lake and dye contaminated water samples.
    Matched MeSH terms: Ultrasonics
  15. Fulltext Towards a New Innovation of Smart Bat Hat for Visually Impaired People
    Saud, Safaa Najah, Muhammad Irsyad Abdullah, Siti Hadijah Shariff, Ram Singh, Ambrick Singh, Baharudin Hamzah, Nordayati Mat Lehat, et al.
    Journal of Management & Science, 2018;16(2):54-66.
    MyJurnal
    Blindness is an area of inadequate the visual conception because of physiological or even neurological aspects. The partial blindness corresponds to the insufficient integration in the expansion of the optic confidence or perhaps visual center of the eye, and also over-all total blindness is the complete inadequacy of the visual light perception. Within this research, a basic, inexpensive, friendly user, sensible blind assist technique is developed to be integrated with the portability of both blind and even visually impaired people in a particular region. The presented work consists of a wearable apparatus is made up of the head hat to facilitate the blind particular person to get around single-handedly safely and securely in order to keep away from any kind of obstructions that could be experienced, even if mounted and also mobile phone, to avoid virtually any probable accident. The primary function of this product is the Ultrasonic sensing unit which is able to inform the blind people if there exist any specific obstacles or otherwise not around them along with the vibrating motor probably would informs the blind people who which negative are the obstacles located. In addition, by pressing the home or work button this system will straight away link to MIT app inventor and the app will send a signal to Google maps to guide the blind people to its desired location. The implemented system is fast, and easy to use and an innovative affordable solution to blind and visually impaired people in third world countries.
    Matched MeSH terms: Ultrasonics
  16. Fulltext Toughness, elasticity and physical properties for the evaluation of foamed concrete reinforced with hybrid fibers
    Dawood ET, Mohammad YZ, Abbas WA, Mannan MA
    Heliyon, 2018 Dec;4(12):e01103.
    PMID: 30603721 DOI: 10.1016/j.heliyon.2018.e01103
    This study has been undertaken to investigate the evaluation of Fiber-reinforced Foamed Concrete (FRFC) performance by the use of toughness and non-destructive tests. These tests cover the workability, density, static modulus of elasticity, toughness, ultrasonic pulse velocity and absorption tests. Different FRFC mixes using carbon fibers in the order of 0.5, 1 and 1.5% carbon fibers were used. Also, the combinations of carbon fibers (C) and polypropylene fibers (PP) as 1% C+ 0.5% PP, and 0.5% C+1% PP were prepared. Lastly, the inclusion of polypropylene fibers with the order of 1.5% PP was used to strengthen the foamed concrete mix. The results showed that the use of 1.5% of C has affected the modulus of elasticity and flexural toughness of foamed concrete. On the other hand, a strong relationship is found between compressive strength and ultrasonic pulse velocity for FRFC.
    Matched MeSH terms: Ultrasonics
  17. Fulltext Tongue pyogenic granuloma excision by using ultrasonic scissors
    Irfan Mohamad, Chentilnathan, Periasamy, Yahia, Dawood
    Archives of Orofacial Sciences, 2011;6(2):1-3.
    MyJurnal
    Pyogenic granuloma is a benign lesion which is commonly found in the oral cavity. It is a reactive inflammatory process of the injured mucosa to trauma. It can appear as a sessile or pedunculated mass with smooth or lobulated surface, which sometimes can mimic malignant lesion. Excision biopsy of the lesion is the confirmatory investigation which also a treatment tool. We report a case of middle-aged lady who had pyogenic granuloma of the tongue, which was safely excised using ultrasonic scissors. This case highlights the new technique of using ultrasonic instruments for excision of benign tongue lesion, with marked reduction of blood loss and operation time.
    Matched MeSH terms: Ultrasonics
  18. Fulltext The use of ultrasound in ocular biometry
    Kuan BB, Lim TK
    Med J Malaysia, 1984 Dec;39(4):280-4.
    PMID: 6544933
    Ultrasound measurement of ocular dimension is the chosen method for assessing axial length when determining dioptric power for intraocular lens. From the current results of 30 cases studied, the mean axial length ranges from 22 to 23 mm. Despite the limitation of the accuracy of the ultrasonic measurements with the 7.5 mHz transducer, the power of intraocular lens can. be determined satisfactorily in accordance with the knowledge of keratometric reading. Hence, high refractive errors could be avoided post-operatively.
    Matched MeSH terms: Ultrasonics*
  19. Fulltext The application of waste marble as coarse aggregate in concrete production
    Chang, Kok Yung, Kwan, Wai Hoe, Kua, Hui Bun
    Scientific Research Journal, 2018;15(1):75-83.
    MyJurnal
    The massive growth of construction industry especially in the developing countries results in extensive quarrying activities which ultimately would lead to the depletion of natural resources. Apart from extensive extraction of the natural granite from the earth for concrete production, marble production industry is also majorly contributing to the quarrying activities. In addition, high volume of waste is generated by the marble production industry as 70% of marble is wasted during the production such as quarrying, cutting, processing and others which is environmental unfriendly. In a way to achieve sustainable construction, the present study is to utilise the waste marble in replacing the coarse aggregate in concrete production. The engineering performance including workability, compressive strength, ultrasonic pulse velocity (UPV) and chloride penetration were analysed. The raw waste marble obtained from the industry were crushed and sieved into maximum size 20 mm and used to replace the coarse aggregate at the level of 20%, 40%, 60%, 80% and 100% respectively. Results show that 60% of the replacement level has yield to optimum result by achieving the highest compressive strength and UPV at approximate 5% higher than the control. Meanwhile, the effect on chloride penetration resistance is more significant, i.e. approximate 19% better than the control. However, increasing the replacement level of waste marble has no significant effect on workability, although an increasing trend was observed.
    Matched MeSH terms: Ultrasonics
  20. Sonophotocatalytic degradation of bisphenol A and its intermediates with graphitic carbon nitride
    Sunasee S, Leong KH, Wong KT, Lee G, Pichiah S, Nah I, et al.
    Environ Sci Pollut Res Int, 2019 Jan;26(2):1082-1093.
    PMID: 28290089 DOI: 10.1007/s11356-017-8729-7
    Since bisphenol A (BPA) exhibits endocrine disrupting action and high toxicity in aqueous system, there are high demands to remove it completely. In this study, the BPA removal by sonophotocatalysis coupled with nano-structured graphitic carbon nitride (g-C3N4, GCN) was conducted with various batch tests using energy-based advanced oxidation process (AOP) based on ultrasound (US) and visible light (Vis-L). Results of batch tests indicated that GCN-based sonophotocatalysis (Vis-L/US) had higher rate constants than other AOPs and especially two times higher degradation rate than TiO2-based Vis-L/US. This result infers that GCN is effective in the catalytic activity in Vis-L/US since its surface can be activated by Vis-L to transport electrons from valence band (VB) for utilizing holes (h+VB) in the removal of BPA. In addition, US irradiation exfoliated the GCN effectively. The formation of BPA intermediates was investigated in detail by using high-performance liquid chromatography-mass spectrometry (HPLC/MS). The possible degradation pathway of BPA was proposed.
    Matched MeSH terms: Ultrasonics/methods
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