Displaying publications 1 - 20 of 225 in total

Abstract:
Sort:
  1. Lim JHC, Azman BAR, Othman BHR
    Zookeys, 2019;859:17-29.
    PMID: 31327920 DOI: 10.3897/zookeys.859.33284
    A new species of caprellid, Aciconulatinggiensis (Amphipoda, Senticaudata, Caprellidae) was discovered from Pulau Tinggi, Sultan Iskandar Marine Park (SIMP), South China Sea, Malaysia. The new Malaysian species can be distinguished from the other Aciconula species by the combination of the following characters: 1. the presence of a very small suture between head and pereonite 1; 2. antenna 1 flagellum with 4 articles; 3. inner lobe of lower lip unilobed; 4. gnathopod 2 palm of propodus with a large proximal projection (stretching from the proximal margin of the palm to nearly mid-way of palm); 5. pereopods 3-4 with 2 articles (article 1 subrectangular, article 2 conical or tapering at the tip with 1 plumose seta and 2 normal setae) and; 6. pereopod 5 covered with relatively dense and long setae. An updated identification key for the five known species in the genus, including information on the respective geographical distribution and habitat, is presented.
    Matched MeSH terms: Zinc Oxide
  2. Aljuboury DA, Palaniandy P, Abdul Aziz HB, Feroz S, Abu Amr SS
    Water Sci Technol, 2016 Sep;74(6):1312-1325.
    PMID: 27685961
    The aim of this study is to investigate the performance of combined solar photo-catalyst of titanium oxide/zinc oxide (TiO2/ZnO) with aeration processes to treat petroleum wastewater. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, air flow, pH, and reaction time to identify the optimum operating conditions. Quadratic models for chemical oxygen demand (COD) and total organic carbon (TOC) removals prove to be significant with low probabilities (<0.0001). The obtained optimum conditions included a reaction time of 170 min, TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), and pH 6.8 COD and TOC removal rates of 99% and 74%, respectively. The TOC and COD removal rates correspond well with the predicted models. The maximum removal rate for TOC and COD was 99.3% and 76%, respectively at optimum operational conditions of TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), reaction time (170 min) and pH (6.8). The new treatment process achieved higher degradation efficiencies for TOC and COD and reduced the treatment time comparing with other related processes.
    Matched MeSH terms: Zinc Oxide/chemistry*
  3. Lee KM, Lai CW, Ngai KS, Juan JC
    Water Res, 2016 Jan 01;88:428-448.
    PMID: 26519627 DOI: 10.1016/j.watres.2015.09.045
    Today, a major issue about water pollution is the residual dyes from different sources (e.g., textile industries, paper and pulp industries, dye and dye intermediates industries, pharmaceutical industries, tannery and craft bleaching industries, etc.), and a wide variety of persistent organic pollutants have been introduced into our natural water resources or wastewater treatment systems. In fact, it is highly toxic and hazardous to the living organism; thus, the removal of these organic contaminants prior to discharge into the environment is essential. Varieties of techniques have been employed to degrade those organic contaminants and advanced heterogeneous photocatalysis involving zinc oxide (ZnO) photocatalyst appears to be one of the most promising technology. In recent years, ZnO photocatalyst have attracted much attention due to their extraordinary characteristics. The high efficiency of ZnO photocatalyst in heterogeneous photocatalysis reaction requires a suitable architecture that minimizes electron loss during excitation state and maximizes photon absorption. In order to further improve the immigration of photo-induced charge carriers during excitation state, considerable effort has to be exerted to further improve the heterogeneous photocatalysis under UV/visible/solar illumination. Lately, interesting and unique features of metal doping or binary oxide photocatalyst system have gained much attention and became favourite research matter among various groups of scientists. It was noted that the properties of this metal doping or binary oxide photocatalyst system primarily depend on the nature of the preparation method and the role of optimum dopants content incorporated into the ZnO photocatalyst. Therefore, this paper presents a critical review of recent achievements in the modification of ZnO photocatalyst for organic contaminants degradation.
    Matched MeSH terms: Zinc Oxide/chemistry*
  4. Bayrami A, Ghorbani E, Rahim Pouran S, Habibi-Yangjeh A, Khataee A, Bayrami M
    Ultrason Sonochem, 2019 Nov;58:104613.
    PMID: 31450359 DOI: 10.1016/j.ultsonch.2019.104613
    The leaf extract of a medicinally important plant, watercress (Nasturtium officinale), was obtained through an ultrasound-facilitated method and utilized for the preparation of ZnO nanoparticles via a joint ultrasound-microwave assisted procedure. The characteristics of the extract enriched nanoparticles (Ext/ZnO) were determined by SEM, TEM, XRD, EDX, BET, FTIR, TGA, and UV-Vis DRS analyses and compared to that of ZnO prepared in the absence of the extract (ZnO). The presence of carbon and carbonaceous bonds, changes in the morphology, size, band gap energy, and weight-decay percentage were a number of differences between ZnO and Ext/ZnO that confirmed the link of extract over nanoparticles. Ext/ZnO, watercress leaf extract, ZnO, and insulin therapies were administrated to treat alloxan-diabetic Wister rats and their healing effectiveness results were compared to one another. The serum levels of the main diabetic indices such as insulin, fasting blood glucose, and lipid profile (total triglyceride, total cholesterol, and high-density lipoprotein cholesterol) were estimated for healthy, diabetic, and the rats rehabilitated with the studied therapeutic agents. The watercress extract-enriched ZnO nanoparticles offered the best performance and suppressed the diabetic status of rats. Moreover, both ZnO samples satisfactory inhibited the activities of Staphylococcus aureus and Escherichia coli bacteria. Based on the results, the application of Nasturtium officinale leaf extract can strongly empower ZnO nanoparticles towards superior antidiabetic and enhanced antibacterial activities.
    Matched MeSH terms: Zinc Oxide/chemistry*
  5. Bayrami A, Alioghli S, Rahim Pouran S, Habibi-Yangjeh A, Khataee A, Ramesh S
    Ultrason Sonochem, 2019 Jul;55:57-66.
    PMID: 31084791 DOI: 10.1016/j.ultsonch.2019.03.010
    The synthesis of nanoparticles often result in the generation of harmful chemical pollutants. As such, many researchers have focused on developing green processes, which include the biosynthesis. In this research, ZnO nanoparticles were prepared using the leaf extract of whortleberry (Vaccinium arctostaphylos L.) via a simple ultrasonic-assisted method. The morphology, crystal size and structure, surface, thermal, and optical properties of the bio-mediated ZnO sample (ZnOext) were analyzed and compared with that produced without incorporating the extract (ZnOchem). The ZnO samples were evaluated for their antidiabetic, antibacterial, as well as their sono- and photo-catalytic performances. Initially, the samples were intraperitoneal injected to alloxan-diabetic rats to examine their treatment efficiency in terms of effects on fasting blood glucose, insulin, cholesterol, high-density lipoprotein, and total triglyceride levels. The ZnOext showed significantly higher efficiency for improving the health status of alloxan-diabetic rats in contrast with other tested treatments, vis. ZnOchem, insulin, and only leaf extract. In addition, both the ZnO samples were assessed against gram-negative and gram-positive bacteria and through sono- and photo-catalytic processes for removing rhodamine B, respectively. The results of this study indicated that not only the ZnOext sample was pollution free, it also exhibited higher potentials for treating diabetic rats, bacterial decontamination, and also oxidative removal of organic compounds under the influences of ultrasound and UV irradiations when compared with ZnOchem sample.
    Matched MeSH terms: Zinc Oxide/pharmacology*; Zinc Oxide/chemistry*
  6. SITI RABIATUL ADAWIYAH MAZLI, HANIS MOHD YUSOFF, NURUL HAYATI IDRIS
    MyJurnal
    Synthesis of nanoparticles by using plant have sparked interest among researchers due to environmentally safe, inexpensive and simple method to compare with chemical method. Use of plant in synthesis zinc oxide nanoparticles (ZnO NPs) that act as reducing and capping agent are more recommended, due to high production of product and rate of synthesis is faster than using microorganism. This study focus on the synthesis of ZnO NPs by using leaf extract of aloe vera (Aloe bardenisis miller) with different concentration (30%, 40% and 50%) and various calcination temperature which are 500 ˚C, 700 ˚C and 900 ˚C for 4 hours. Fourier – transform infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), scanning electron microscopy (SEM), X-ray Diffraction (XRD) and Brunauer-Emmet and Teller (BET) were used to characterize the prepared samples. FTIR spectra showed present wavenumber in between 400-500 cm-1 indicated the presence of Zn-O stretch. Powder XRD pattern confirmed the hexagonal wurtzite structure with average particles size from 24.19 nm to 67.69 nm for all concentration and temperature by using Scherer’s equation. For SEM analysis the images show irregular shape for concentrations 30% and 50% with size range from 500 nm to 900 nm while for concentration 40% cubic shape was observe with size range from 140 nm to 900 nm. All characterize show that formation of ZnO NPs depend on the concentration and calcination temperature. Sample 30% and 50% ZnO NPs was applied in lithium battery at voltage from 0.01 to 3. 1.2 mAhg-1 was recorded for sample 30% ZnO NPs while 100 mAhg-1.
    Matched MeSH terms: Zinc Oxide
  7. MOHAMAD HANIF AKMAL HUSSIN, WAN RAFIZAH WAN ABDULLAH, MOHAMAD AWANG
    MyJurnal
    Semiconductor oxides such as titanium dioxide (TiO2) and zinc oxide (ZnO) are used as the photocatalyst for removing contaminants. In addition, TiO2 and ZnO nanoparticles in the suspension form makes it difficult to be recovered and recycled. This study was conducted to investigate the efficiency of immobilizing TiO2 and ZnO nanoparticles in epoxy beads. The immobilization process using different ratios of photocatalysts TiO2/ZnO (1:0, 3:1, 1:1, 1:3 and 0:1) fixed on epoxy material. These epoxy beads were used for dye removal in photocatalysis using methylene blue (MB) solution at a concentration of 10mg/L. Besides, epoxy beads also characterized using scanning electron microscope (SEM), attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA). The results showed that the highly recommended epoxy bead is 3:1 ratio of TiO2/ZnO because it has good performance in dye degradation that proved from reducing concentration of MB to 2.4mg/L (76%). However, TiO2/ZnO characterization of 3:1 by SEM show on the surface the particle are found to be spherical in shape which is relatively high efficiency for the degradation, ATR-FTIR pattern in broad band 4000 cm-1 - 400cm-1 which correspond to hydroxyl stretching to be adsorbed at peak (474.49 cm-1 - 3722.61cm-1) respectively to the optimum for the degradation and TGA rate of change are 5mg to 2.5mg that residue (49.78%) due to decomposition or oxidation from mass loss. These findings are very effective and economical technique to be cost saving and highly efficient photocatalyst.
    Matched MeSH terms: Zinc Oxide
  8. FARAH EILYANA MOHAMED
    MyJurnal
    Solar photocatalysis is a green technology that takes advantage of sustainable solar energy for enhancing oxidation process of numerous harmful water contaminants. In this study, a custom solar driven zinc oxide (ZnO)-mediated photocatalytic system was developed and its efficiency to remove organic contaminants as well as to disinfect selected bacteria was investigated. Methylene blue (MB) dye was used as the model organic contaminant, while Escherichia coli(E.coli) was used as the model fecal coliform bacteria in contaminated water. A series of photodegradation experiments were conducted on water contaminated with either 10 mg/L of MB or ~1010CFU/ml of E.coli. The experiments were completed under sunlight irradiation in the presence of 1 g/L of nano ZnO photocatalyst for up to 6 hours. Using a solar thermal collector, the photoreactor operated in the temperature range of 25 to 50 oC. The findings revealed that the combination of solar thermal with solar photocatalysis usingZnO intensified the degradation of MB and disinfection of E.coli. 98.08% of MB dye and 99.99% of E.coliwere successfully removed from the water within the first 3 hours of treatment. Almost complete removal was eventually achieved after 6 hours of treatment. It is therefore suggested that ZnO-based solar photocatalytic system developed in this study is highly efficient at enhancing water decontamination process.
    Matched MeSH terms: Zinc Oxide
  9. Abdollahi Y, Zakaria A, Sairi NA, Matori KA, Masoumi HR, Sadrolhosseini AR, et al.
    ScientificWorldJournal, 2014;2014:726101.
    PMID: 25538962 DOI: 10.1155/2014/726101
    The artificial neural network (ANN) modeling of m-cresol photodegradation was carried out for determination of the optimum and importance values of the effective variables to achieve the maximum efficiency. The photodegradation was carried out in the suspension of synthesized manganese doped ZnO nanoparticles under visible-light irradiation. The input considered effective variables of the photodegradation were irradiation time, pH, photocatalyst amount, and concentration of m-cresol while the efficiency was the only response as output. The performed experiments were designed into three data sets such as training, testing, and validation that were randomly splitted by the software's option. To obtain the optimum topologies, ANN was trained by quick propagation (QP), Incremental Back Propagation (IBP), Batch Back Propagation (BBP), and Levenberg-Marquardt (LM) algorithms for testing data set. The topologies were determined by the indicator of minimized root mean squared error (RMSE) for each algorithm. According to the indicator, the QP-4-8-1, IBP-4-15-1, BBP-4-6-1, and LM-4-10-1 were selected as the optimized topologies. Among the topologies, QP-4-8-1 has presented the minimum RMSE and absolute average deviation as well as maximum R-squared. Therefore, QP-4-8-1 was selected as final model for validation test and navigation of the process. The model was used for determination of the optimum values of the effective variables by a few three-dimensional plots. The optimum points of the variables were confirmed by further validated experiments. Moreover, the model predicted the relative importance of the variables which showed none of them was neglectable in this work.
    Matched MeSH terms: Zinc Oxide/chemistry*
  10. Dorraj M, Zakaria A, Abdollahi Y, Hashim M, Moosavi S
    ScientificWorldJournal, 2014;2014:741034.
    PMID: 25243225 DOI: 10.1155/2014/741034
    In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this study, the optimal dopant levels of Bi2O3, TiO2, and Sb2O3 to achieve maximized nonlinear electrical property (alpha) were quantified by the response surface methodology (RSM). RSM was also used to understand the significance and interaction of the factors affecting the response. Variables were determined as the molar ratio of Bi2O3, TiO2, and Sb2O3. The alpha was chosen as response in the study. The 5-level-3-factor central composite design, with 20 runs, was used to conduct the experiments by ball milling method. A quadratic model was established as a functional relationship between three independent variables and alpha. According to the results, the optimum values of Bi2O3, TiO2, and Sb2O3 were obtained 0.52, 0.50, and 0.30, respectively. Under optimal conditions the predicted alpha (9.47) was calculated using optimal coded values from the model and the theoretical value is in good agreement with the value (9.43) obtained by confirmation experiment.
    Matched MeSH terms: Zinc Oxide/standards; Zinc Oxide/chemistry*
  11. Yarmand H, Gharehkhani S, Kazi SN, Sadeghinezhad E, Safaei MR
    ScientificWorldJournal, 2014;2014:369593.
    PMID: 25254236 DOI: 10.1155/2014/369593
    Thermal characteristics of turbulent nanofluid flow in a rectangular pipe have been investigated numerically. The continuity, momentum, and energy equations were solved by means of a finite volume method (FVM). The symmetrical rectangular channel is heated at the top and bottom at a constant heat flux while the sides walls are insulated. Four different types of nanoparticles Al2O3, ZnO, CuO, and SiO2 at different volume fractions of nanofluids in the range of 1% to 5% are considered in the present investigation. In this paper, effect of different Reynolds numbers in the range of 5000 < Re < 25000 on heat transfer characteristics of nanofluids flowing through the channel is investigated. The numerical results indicate that SiO2-water has the highest Nusselt number compared to other nanofluids while it has the lowest heat transfer coefficient due to low thermal conductivity. The Nusselt number increases with the increase of the Reynolds number and the volume fraction of nanoparticles. The results of simulation show a good agreement with the existing experimental correlations.
    Matched MeSH terms: Zinc Oxide/chemistry
  12. Saifullah B, Arulselvan P, El Zowalaty ME, Fakurazi S, Webster TJ, Geilich B, et al.
    ScientificWorldJournal, 2014;2014:401460.
    PMID: 25050392 DOI: 10.1155/2014/401460
    Tuberculosis is a lethal epidemic, difficult to control disease, claiming thousands of lives every year. We have developed a nanodelivery formulation based on para-aminosalicylic acid (PAS) and zinc layered hydroxide using zinc nitrate salt as a precursor. The developed formulation has a fourfold higher efficacy of PAS against mycobacterium tuberculosis with a minimum inhibitory concentration (MIC) found to be at 1.40 μg/mL compared to the free drug PAS with a MIC of 5.0 μg/mL. The newly developed formulation was also found active against Gram-positive bacteria, Gram-negative bacteria, and Candida albicans. The formulation was also found to be biocompatible with human normal lung cells MRC-5 and mouse fibroblast cells-3T3. The in vitro release of PAS from the formulation was found to be sustained in a human body simulated phosphate buffer saline (PBS) solution at pH values of 7.4 and 4.8. Most importantly the nanocomposite prepared using zinc nitrate salt was advantageous in terms of yield and free from toxic zinc oxide contamination and had higher biocompatibility compared to one prepared using a zinc oxide precursor. In summary, these promising in vitro results are highly encouraging for the continued investigation of para-aminosalicylic acid and zinc layered hydroxide nanocomposites in vivo and eventual preclinical studies.
    Matched MeSH terms: Zinc Oxide/chemistry
  13. 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: Zinc Oxide/chemistry*
  14. Tapsir Z, Aly Ahmed HM, Luddin N, Husein A
    J Contemp Dent Pract, 2013 Jan 1;14(1):47-50.
    PMID: 23579892
    To evaluate and compare the microleakage of various restorative materials used as coronal barriers between endodontic appointments.
    Matched MeSH terms: Zinc Oxide/chemistry
  15. Kamari Z
    Malays J Med Sci, 2009 Jan;16(1):16-24.
    PMID: 22589644 MyJurnal
    Our Hospital University Sains Malaysia (HUSM) was given the Cabinet approval to exist under the Ministry of Education on 23 November 1982. The Deputy Prime Minister during that period, Yang Berhormat Tun Musa Hitam announced this after the cabinet meeting was held together with the presence of the Yang Berhormat Ministers of Health; and Education, Director of the Public Works Department and the Implementation and Coordinating Unit, Prime Minister's Department. The first patients moved in on 14 March 1983 and the inauguration of HUSM was done on 26 August 1984 by the Duli Yang Maha Mulia Tuanku Ismail Petra Ibni Al-Marhum Sultan Yahya Petra, the Sultan of Kelantan Darul Naim. HUSM celebrated it's 25th anniversary at the Dewan Utama, USM Health Campus on the 15th December 2008 which was inaugurated by Yang Berhormat, Minister of Higher Education Dato' Seri Mohamed Khaled Nordin. USM's Vice Chancellor Professor Tan Sri Dato' Dzulkifli Abdul Razak, Chairman of the USM Board of Directors Tan Sri Dato' Haji Dr. Ani bin Arope, Health Campus Director Professor Dato' Dr. Mafauzy Mohamed, former Campus Director, Dato' Prof Mohd Roslani Abdul Majid, the current and previous Hospital Directors and Deputy Directors since 1983 were present. The achievements of HUSM since its establishment and its vision to fulfil the University's Accelerated Programme for Excellence (APEX) are elaborated.
    Matched MeSH terms: Zinc Oxide
  16. Adnan M, Abdullah JM, Ibharim LFM, Hoe TW, Janan D, Abdullah N, et al.
    Malays J Med Sci, 2019 Jul;26(4):127-133.
    PMID: 31496902 MyJurnal DOI: 10.21315/mjms2019.26.4.15
    This study presents the results of a year-long project focused on analysis and reflection on working with comics by Year One students in Hulu Langat districts. This study presents the use of science, technology, engineering and mathematics (STEM) comics to help children understand certain physical phenomena and try to make students interested in mathematics and science subject. Thirteen excellent teachers of science and mathematics from the Hulu Langat district were involved in the analysis of syllabus Year One science and mathematics subjects and the preparation of scripts while the STEM comic illustrator was created by two lecturers from the Faculty of Art, Computing and Creative Industry from Universiti Pendidikan Sultan Idris, Perak Malaysia. The study is based on observations of changing perception of phenomena by children as a result of the use of comics. As a result, a STEM comic that contains ten series for Year One science and mathematics subjects has been successfully developed. This comic is expected to attract and enhance the achievement of Year One students in science and mathematics. Implication of this study, STEM comics can be used by teachers as science and mathematics teaching aids. Comics are proven to be a modern pedagogical strategy, which is starting to gain its popularity in teaching about mathematics and science. Comics can be very helpful tools in making science and mathematics concepts interesting, fun learning and comprehensible for a Year One children.
    Matched MeSH terms: Zinc Oxide
  17. Chong LE, Jow TK
    Dent J Malaysia Singapore, 1967 Oct;7(2):44-51.
    PMID: 5247441
    Matched MeSH terms: Zinc Oxide-Eugenol Cement/therapeutic use
  18. Ng SM, Wong DS, Phung JH, Chin SF, Chua HS
    Talanta, 2013 Nov 15;116:514-9.
    PMID: 24148438 DOI: 10.1016/j.talanta.2013.07.031
    Quantum dots are fluorescent semiconductor nanoparticles that can be utilised for sensing applications. This paper evaluates the ability to leverage their analytical potential using an integrated fluorescent sensing probe that is portable, cost effective and simple to handle. ZnO quantum dots were prepared using the simple sol-gel hydrolysis method at ambient conditions and found to be significantly and specifically quenched by copper (II) ions. This ZnO quantum dots system has been incorporated into an in-house developed miniature fluorescent probe for the detection of copper (II) ions in aqueous medium. The probe was developed using a low power handheld black light as excitation source and three photo-detectors as sensor. The sensing chamber placed between the light source and detectors was made of 4-sided clear quartz windows. The chamber was housed within a dark compartment to avoid stray light interference. The probe was operated using a microcontroller (Arduino Uno Revision 3) that has been programmed with the analytical response and the working algorithm of the electronics. The probe was sourced with a 12 V rechargeable battery pack and the analytical readouts were given directly using a LCD display panel. Analytical optimisations of the ZnO quantum dots system and the probe have been performed and further described. The probe was found to have a linear response range up to 0.45 mM (R(2)=0.9930) towards copper (II) ion with a limit of detection of 7.68×10(-7) M. The probe has high repeatable and reliable performance.
    Matched MeSH terms: Zinc Oxide/chemistry*
  19. Halimah MK, Ami Hazlin MN, Muhammad FD
    Spectrochim Acta A Mol Biomol Spectrosc, 2018 Apr 15;195:128-135.
    PMID: 29414569 DOI: 10.1016/j.saa.2017.12.054
    A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Dy2O3)xwhere x=0.01, 0.02, 0.03, 0.04 and 0.05M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3,TeO4and TeO3vibrational groups. The density of the glass systems is increased with the addition of Dy2O3while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the4F9/2→6H15/2and4F9/2→6H13/2transitions of Dy3+ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region.
    Matched MeSH terms: Zinc Oxide
  20. Tan KH, Lim FS, Toh AZY, Zheng XX, Dee CF, Majlis BY, et al.
    Small, 2018 May;14(20):e1704053.
    PMID: 29665226 DOI: 10.1002/smll.201704053
    Observation of visible light trapping in zinc oxide (ZnO) nanorods (NRs) correlated to the optical and photoelectrochemical properties is reported. In this study, ZnO NR diameter and c-axis length respond primarily at two different regions, UV and visible light, respectively. ZnO NR diameter exhibits UV absorption where large ZnO NR diameter area increases light absorption ability leading to high efficient electron-hole pair separation. On the other hand, ZnO NR c-axis length has a dominant effect in visible light resulting from a multiphoton absorption mechanism due to light reflection and trapping behavior in the free space between adjacent ZnO NRs. Furthermore, oxygen vacancies and defects in ZnO NRs are associated with the broad visible emission band of different energy levels also highlighting the possibility of the multiphoton absorption mechanism. It is demonstrated that the minimum average of ZnO NR c-axis length must satisfy the linear regression model of Z p,min = 6.31d to initiate the multiphoton absorption mechanism under visible light. This work indicates the broadening of absorption spectrum from UV to visible light region by incorporating a controllable diameter and c-axis length on vertically aligned ZnO NRs, which is important in optimizing the design and functionality of electronic devices based on light absorption mechanism.
    Matched MeSH terms: Zinc Oxide
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links