24 research outputs found

    Role Enhancement of ZnO nanoparticles and ZnO/Ag composite for Medical Applications

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    ZnO nanoparticles assisted with ethanol and 2propanol as capping agent investigated the medical activities of ZnO nanoparticles and ZnO/Ag composite. ZnO nanoparticles were prepared using zinc acetate and silver nitrate as a source of zinc and silver. ZnO/Ag composite also prepared and studied the medical activities. XRD pattern indicates that the structure of ZnO was hexagonal wurtzite with average size 5 nm according to Scherre's formula. The optical band gap of ZnO nanoparticle showed very sensitive for using different capping agent as shown in UV-VIS spectra and also showed blue shift in wavelength corresponding to capping agent. Finally, the antibacterial properties of ZnO and ZnO/Ag composite against Gram-negative and Gram-positive bacteria have been demonstrated using well diffusion method and indentify their antibacterial effects compared with organic antibacterial agents. Keywords: ZnO nanoparticles, ZnO/Ag composite, antibacterial

    Enhancement of DSSC by Using Gold Nanoparticles

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    In this research, AuNPs prepared by laser ablation in liquid (PLAL) at 750 mJ energy and 90 pulses. They have been added to N719-dye to form (Au-N719) mixture. TiO2 paste was deposited on FTO substrates and immersion in a mixture dye and AuNPs. DSSC was fabricated and enhancement of the DSSC conversion efficiency was achieved. Scanning electron microscope, X-ray diffraction and UV-Visible spectrophotometer were used to characterize and study the DSSC components. The UV-Vis data show high absorbance of AuNPs+N719 dye compared to N719 dye only; that means the immersion of AuNPs in the N719-dye solution tend to increase the total absorbance of the dye. The XRD pattern of AuNPs has diffraction peaks at 38.2° and 44.4° which can be indexed by (111), (200) plane of Au in the cubic phase. The shape and size distribution shows spherical AuNPs with particle size about (50-60) nm. The relative increase of short circuit current density after the adding gold nanoparticles was about 76%. In the same way the relative increase of open circuit voltage after adding gold nanoparticles was about 6.7%. The total photon-to-current energy conversion efficiency for the standard DSSC is 1.75 while its 2.8 of the enhanced DSSC with gold NPs.The maximum enhancement is about 60 % under illumination (105 mW/cm2, (AM1.5)

    Preparing of Barium Titanate Using Chemical Method and Studying of Its Structural Properties

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    Single crystalline BaTiO3 (BT) was prepared using TiCl4, BaCl2 and oxalic acid. The structure of the prepared nanocrystalline BT powders were a tetragonal perovskite according to XRD and HRTEM analysis. Annealing powder to 750oC show that pure BT phase was formed according to XRD, TG, and FTIR spectroscopy. The TEM images of the prepared powder reveal spherical morphology of BT, while a finger twin, dendritic and embryo shape are observed of BT powder calcined at 230, 530, and 750oC respectively. SAED and HRTEM images showed a high crystalline BT powder and a single crystalline BT respectively

    Efficacy evaluation of empty palm oil fruit bunch compost in improving soil characteristics, plant growth and disease suppression of tomato plants under tropical acid soils

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    Aim: Tomato is one of the most important crops worldwide as it is the second most important vegetable in the world after potato. A study was conducted to investigate the efficacy of empty fruit bunch (EFB) compost in improving soil characteristics, plant growth and disease suppression of tomato plants under tropical acid soil. Methodology: Twelve tomato seedling cv MT-11 were transplanted on each planting bed. The growth of tomato plant was assessed based on plant height, leaf area, dry matter weight and incidence of bacterial wilt disease. Soil sampling was done at 45 and 60 day after transplanting (DAT) for physio-chemical and microbial properties. Results: Applying EFB compost increased plant height, leaf area, dry matter accumulation, and suppressed development of bacterial wilt disease compared to using chicken manure. A higher disease reduction (16.7 %) occurred with 15 mg ha⁻¹ EFB compost, followed by 22.5 mg ha⁻¹ EFB compost (14.3 %), and 7.5 mg ha⁻¹ EFB compost (8.33 %). Interpretation: Organic amendment in tomato cultivation affects soil properties, plant development and disease suppression. Application of EFB compost at 15 mg ha⁻¹ appeared as the best treatment soil amendment in tomato cultivation under tropical acidicsoil condition

    Youtube Usage Pattern Among Communication Science Students

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    This study aims to determine the motives and patterns of using youtube among Communication science students. This research was conducted using quantitative methods. Data was collected online using a questionnaire created on Google Form. The questionnaire link was distributed using the crowdsourcing method using Whatsapp. The population of this study were students majoring in Communication Science, Faculty of Social and Political Sciences (FISIP), Makassar Islamic University. We have described both the cognitive motive and the affective motive. Second, we have calculated the value of the motive for both and found that the value of cognitive motive is slightly higher than the value of affective motive. This means that the cognitive motives and affective motives of students in using Youtube are quite balanced

    Intensity modulated silver coated glass optical fiber refractive index sensor

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    Miniature optical fiber sensors with thin films as sensitive elements could open new fields for optical fiber sensor applications. Thin films work as sensitive elements and a transducer to get response and feedback from environments, in which optical fibers act as a signal carrier. A novel Ag coated intensity modulated optical fiber sensor based on refractive index changes using IR and UV-Vis (UV-visible) light sources is proposed. The sensor with an IR light source has higher sensitivity compared to a UV-Vis source. When the refractive index is enhanced to 1.38, the normalized intensity of IR and UV-Vis light diminishes to 0.2 and 0.8, respectively

    Properties of Al- and Ga-doped thin zinc oxide films treated with UV laser radiation

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    This paper reports the Nd:YAG laser irradiation treated modified properties of aluminum (Al) and gallium (Ga) co-doped zinc oxide (ZnO) (AGZO) films prepared on Si-substrate via combined sol–gel and spin-coating method. The impact of varying laser energy (150–200 mJ) on the structure, morphology, electrical and optical properties of such AGZO films were determined. Laser-treated samples were characterized using various analytical tools. Present techniques could achieve a high-quality polycrystalline films compared with those produced via conventional high temperature processing. AGZO films irradiated with third harmonics UV radiation (355 nm) from Nd:YAG laser source revealed very low resistivity of 4.02 × 10− 3 Ω cm. The structural properties grain size was calculated firm the X-ray diffraction spectra using the Scherrer equation that increased from 12.7 to 22.5 nm as the annealing laser energy increased from (150–200) mJ. The differences in crystallinity and orientation are explained in terms of the thermal effect caused by laser irradiation. (FESEM) images have been demonstrated that Nd:YAG laser annealing can significantly improve the crystallinity level, densification, and surface flatness of sol–gel derived AGZO thin films that occurred as a result of laser processing. Synthesized AGZO films displayed favorable growth orientation along (101) lattice direction. AGZO films with energy band gap of 3.37–3.41 eV were obtained. Results on the crystallinity, surface morphology, roughness, bonding vibration, absorption, photoluminescence, and resistivity of the laser-irradiated films were analyzed and discussed

    Nanocomposite membrane by incorporating graphene oxide in sulfonated polyether ether ketone for direct methanol fuel cell

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    Few-layers graphene oxide enriched with oxygen functional groups is successfully obtained and incorporated into sulfonated polyether ether ketone (SPEEK) matrix. The functional groups and the surface modification of membranes were identified using FTIR spectroscopy, and X-ray Photoelectron Spectroscopy (XPS). Subsequently, FESEM was employed to study the surface morphology changes, and the X-Ray diffraction (XRD) was performed to ascertain the crystallinity of the fabricated membrane. The distribution of carbonaceous fillers GO in SPEEK matrix was found to actively improved the ion exchange capacity (IEC), and concurrently obstructed the methanol crossover, thus making them intriguing candidates as proton exchange membranes (PEMs)

    Preparation and characterization of hydrophilic surface modifier macromolecule modified poly (ether sulfone) photocatalytic membrane for phenol removal

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    A modified poly (ether sulfone) (PES) by hydrophilic surface modifying macromolecules (LSMM) incorporated with oxygenated graphitic carbon nitride (OGCN) photocatalyst (PES/OGCN-LSMM) was successfully prepared as a hybrid photocatalytic membrane. The effect of solvent evaporation time during membrane fabrication was studied by focusing on the positioning of LSMM in order to provide the desirable properties of the PES/OGCN-LSMM hybrid membrane for phenol removal performance by photocatalytic and separation. The PES/OGCN-LSMM membranes exhibited a decreased value of contact angle as the solvent evaporation time increased. The SEM images revealed a dense top layer supported by finger-like structures underneath, which was formed for the membranes at 0–4 min solvent evaporation time, while a sponge-like microvoid structure was observed at 5 min of solvent evaporation time. It is interesting to highlight that as the evaporation time increased, the pure water flux decreased as the result of compact denser membrane. Benefitting the special feature of LSMM that tends to migrate upwards upon mixing, the LSMM effectively assisted OGCN photocatalyst to the top layer of the membrane. This was revealed by SEM top surface images that more OGCN photocatalyst particles were seen distributed on the dense top layer of the membrane upon longer solvent evaporation time supported by the membrane topography analysis. It was found that the phenol reduction by rejection and photocatalytic tests was the highest at 5 min solvent evaporation time, whilst water flux was the lowest. The obtained results showed that the LSMM has indeed assisted the positioning of OGCN towards the top layer of the membrane and consequently increased the photocatalytic activity of the membrane on phenol
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