Displaying publications 21 - 40 of 181 in total

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  1. Fulltext Novel Functionalized Polythiophene-Coated Fe₃O₄ Nanoparticles for Magnetic Solid-Phase Extraction of Phthalates
    Baharin SNA, Muhamad Sarih N, Mohamad S
    Polymers (Basel), 2016 Apr 28;8(5).
    PMID: 30979266 DOI: 10.3390/polym8050117
    Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy)-benzylidene)-amine) (P3TArH) was successfully synthesized and coated on the surface of Fe₃O₄ magnetic nanoparticles (MNPs). The nanocomposites were characterized by Fourier transform infra-red (FTIR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, analyzer transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). P3TArH-coated MNPs (MNP@P3TArH) showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE) of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCP), di-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DNOP), were conducted by a gas chromatography-flame ionization detector (GC-FID). The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L-1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1⁻50 µg·L-1 and a limit of detection at 0.08⁻0.468 µg·L-1 for all of the analytes studied. The intra-day (n = 7) and inter-day (n = 3) relative standard deviations (RSD%) of three replicates were each demonstrated in the range of 3.7⁻4.9 and 3.0⁻5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%⁻101% and RSD% lower than 7.7 were attained.
    Matched MeSH terms: Fourier Analysis
  2. Mineral and physiochemical evaluation of cockle shell (Anadara granosa) and other selected molluscan shell as potential biomaterials
    Bharatham H, Md Zuki Abu Bakar Zakaria, Perimal EK, Loqman Mohamad Yusof, Muhajir Hamid
    Sains Malaysiana, 2014;43:1023-1029.
    Molluscan shells are attracting research interest due to the diverse application properties possessed. As shells are very similar to bones, this study was conducted to analyze the mineral and physiochemical composition of Cockle (Anadara granosa) shell and three other types of molluscan shell, namely Strombus canarium, Oliva sayana and Terebra dislocata as potential biomaterial for bone tissue engineering applications. Approximately 200 g of shells from each species were processed and powdered for the purpose of this study. Carbon was analyzed using the carbon analyzer while minerals and heavy metals through ICP-MS. The phase purity and crystallographic structures of the powders were identified using X-Ray Diffractometer (XRD) while the chemical functionality was determined using the Fourier transform infrared (FTIR) spectrophotometer. The analysis showed that Cockle shells contained higher content of calcium and carbon including varying amount of other minor elements comparatively. However, all four types of shell powders were found to contain below detectable levels of toxic elements. Physiochemical analysis on phase purity and crystallographic structures showed similar characteristics of carbonate group present in all four shell types. A predominantly aragonite form of calcium carbonate was detected in both XRD diffractogram and FTIR spectra for all samples. Our findings demonstrated that different types of molluscan shells have almost similar mineral and physiochemical characteristics and a predominantly aragonite form of calcium carbonate that provides a strong basis for their use as a potential bone tissues engineering material.
    Matched MeSH terms: Fourier Analysis
  3. Harmonic phase interference for the detection of tag line crossings and beyond in homogeneous strain analysis of cardiac tagged MRI data
    Bilgen M
    Australas Phys Eng Sci Med, 2010 Dec;33(4):357-66.
    PMID: 21110236 DOI: 10.1007/s13246-010-0039-z
    Homogenous strain analysis (HSA) was developed to evaluate regional cardiac function using tagged cine magnetic resonance images of heart. Current cardiac applications of HSA are however limited in accurately detecting tag intersections within the myocardial wall, producing consistent triangulation of tag cells throughout the image series and achieving optimal spatial resolution due to the large size of the triangles. To address these issues, this article introduces a harmonic phase (HARP) interference method. In principle, as in the standard HARP analysis, the method uses harmonic phases associated with the two of the four fundamental peaks in the spectrum of a tagged image. However, the phase associated with each peak is wrapped when estimated digitally. This article shows that special combination of wrapped phases results in an image with unique intensity pattern that can be exploited to automatically detect tag intersections and to produce reliable triangulation with regularly organized partitioning of the mesh for HSA. In addition, the method offers new opportunities and freedom for evaluating myocardial function when the power and angle of the complex filtered spectra are mathematically modified prior to computing the phase. For example, the triangular elements can be shifted spatially by changing the angle and/or their sizes can be reduced by changing the power. Interference patterns obtained under a variety of power and angle conditions were presented and specific features observed in the results were explained. Together, the advanced processing capabilities increase the power of HSA by making the analysis less prone to errors from human interactions. It also allows strain measurements at higher spatial resolution and multi-scale, thereby improving the display methods for better interpretation of the analysis results.
    Matched MeSH terms: Fourier Analysis
  4. Fulltext Synthesis of silver nanoparticles in chitosan, gelatin and chitosan/gelatin bionanocomposites by a chemical reducing agent and their characterization
    Bin Ahmad M, Lim JJ, Shameli K, Ibrahim NA, Tay MY
    Molecules, 2011 Aug 25;16(9):7237-48.
    PMID: 21869751 DOI: 10.3390/molecules16097237
    In this research, silver nanoparticles (AgNPs) were synthesized in chitosan (Cts), Cts/gelatin and gelatin suspensions using a chemical reducing agent. Cts and gelatin were used as natural stabilizers and solid support, whereas AgNO(3) was used as the silver precursor. Sodium borohydride (NaBH(4)) was used as the reducing agent. The properties of AgNPs in Cts, Cts/gelatin and gelatin bionanocomposites (BNCs) were studied in terms of their surface plasmon resonance, crystalline structure, average diameter size, particle distributions, surface topography and functional groups. All the samples were characterized by UV-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy.
    Matched MeSH terms: Fourier Analysis
  5. Delineation of the intimate details of the backbone conformation of pyridine nucleotide coenzymes in aqueous solution
    Bose KS, Sarma RH
    Biochem Biophys Res Commun, 1975 Oct 27;66(4):1173-9.
    PMID: 2
    Matched MeSH terms: Fourier Analysis
  6. Fulltext Thixotropic Supramolecular Pectin-Poly(Ethylene Glycol) Methacrylate (PEGMA) Hydrogels
    Chan SY, Choo WS, Young DJ, Loh XJ
    Polymers (Basel), 2016 Nov 18;8(11).
    PMID: 30974681 DOI: 10.3390/polym8110404
    Pectin is an anionic, water-soluble polymer predominantly consisting of covalently 1,4-linked α-d-galacturonic acid units. This naturally occurring, renewable and biodegradable polymer is underutilized in polymer science due to its insolubility in organic solvents, which renders conventional polymerization methods impractical. To circumvent this problem, cerium-initiated radical polymerization was utilized to graft methoxy-poly(ethylene glycol) methacrylate (mPEGMA) onto pectin in water. The copolymers were characterized by ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), and used in the formation of supramolecular hydrogels through the addition of α-cyclodextrin (α-CD) to induce crosslinking. These hydrogels possessed thixotropic properties; shear-thinning to liquid upon agitation but settling into gels at rest. In contrast to most of the other hydrogels produced through the use of poly(ethylene glycol) (PEG)-grafted polymers, the pectin-PEGMA/α-CD hydrogels were unaffected by temperature changes.
    Matched MeSH terms: Fourier Analysis
  7. Fulltext Functionalized KIT-6/Polysulfone Mixed Matrix Membranes for Enhanced CO2/CH4 Gas Separation
    Chew TL, Ding SH, Oh PC, Ahmad AL, Ho CD
    Polymers (Basel), 2020 Oct 09;12(10).
    PMID: 33050226 DOI: 10.3390/polym12102312
    The development of mixed matrix membranes (MMMs) for effective gas separation has been gaining popularity in recent years. The current study aimed at the fabrication of MMMs incorporated with various loadings (0-4 wt%) of functionalized KIT-6 (NH2KIT-6) [KIT: Korea Advanced Institute of Science and Technology] for enhanced gas permeation and separation performance. NH2KIT-6 was characterized by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and N2 adsorption-desorption analysis. The fabricated membranes were subjected to FESEM and FTIR analyses. The effect of NH2KIT-6 loading on the CO2 permeability and ideal CO2/CH4 selectivity of the fabricated membranes were investigated in gas permeation and separation studies. The successfulness of (3-Aminopropyl) triethoxysilane (APTES) functionalization on KIT-6 was confirmed by FTIR analysis. As observed from FESEM images, MMMs with no voids in the matrix were successfully fabricated at a low NH2KIT-6 loading of 0 to 2 wt%. The CO2 permeability and ideal CO2/CH4 selectivity increased when NH2KIT-6 loading was increased from 0 to 2 wt%. However, a further increase in NH2KIT-6 loading beyond 2 wt% led to a drop in ideal CO2/CH4 selectivity. In the current study, a significant increase of about 47% in ideal CO2/CH4 selectivity was achieved by incorporating optimum 2 wt% NH2KIT-6 into the MMMs.
    Matched MeSH terms: Fourier Analysis
  8. Fulltext Isolation and Characterization of Cellulose Nanocrystals from Oil Palm Mesocarp Fiber
    Chieng BW, Lee SH, Ibrahim NA, Then YY, Loo YY
    Polymers (Basel), 2017 Aug 11;9(8).
    PMID: 30971032 DOI: 10.3390/polym9080355
    The aim was to explore the utilization of oil palm mesocarp fiber (OPMF) as a source for the production of cellulose nanocrystals (CNC). OPMF was first treated with alkali and then bleached before the production of CNC by acid hydrolysis (H₂SO₄). The produced materials were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It was proven that acid hydrolysis can increase the crystallinity of bleached OPMF and reduce the dimension of cellulose to nano scale. Changes in the peaks of the FTIR spectrum at 2852 (C-H stretching), 1732 (C=O stretching) and 1234 cm-1 (C-O stretching) indicated that the alkali treatment completely removed hemicelluloses and lignin from the fiber surface. This can be seen from the thermogram obtained from the TGA characterization. Morphological characterization clearly showed the formation of rod-shaped CNCs. The promising results prove that OPMF is a valuable source for the production of CNC.
    Matched MeSH terms: Fourier Analysis
  9. Phomopsidione-Loaded Chitosan Polyethylene Glycol (PEG) Nanocomposite Dressing for Pressure Ulcers
    Chin IBI, Yenn TW, Ring LC, Lazim Y, Tan WN, Rashid SA, et al.
    J Pharm Sci, 2020 09;109(9):2884-2890.
    PMID: 32534882 DOI: 10.1016/j.xphs.2020.06.005
    Pressure ulcers are commonly associated with microbial infections on the wounds which require an effective wound dressing for treatment. Thus far, the available silver dressing has shown tremendous result, however, it may cause argyria and complicate the internal organ function. Hence, our study aims to develop and characterize phomopsidione-loaded chitosan-polyethylene glycol nanocomposite hydrogel (C/PEG/Ph) as an antimicrobial dressing. Physically, the C/PEG/Ph hydrogel demonstrated a uniform light blue color, soft, flexible, and elastic, with no aggregation form. The evaluation via Fourier Transform Infrared (FTIR) exposed the C/PEG/Ph hydrogel has a notable shift towards lower frequency at 1600 and 1554 cm-1. For drug release test, the phomopsidione attained plateau at 24 h, with a total release of 67.9 ± 6.4% from the C/PEG/Ph hydrogel. There was a null burst release effect discovered throughout the experimental period. The C/PEG/Ph hydrogel showed significant results against all 4 Gram-negative bacteria and 1 yeast, with 99.99-100% reduction of microbial growth. The findings revealed that the C/PEG/Ph hydrogel can potentially act as an antimicrobial dressing for pressure ulcers.
    Matched MeSH terms: Fourier Analysis
  10. Fulltext Parametric Studies of Titania-Supported Gold-Catalyzed Oxidation of Carbon Monoxide
    Chong S, Yang TC
    Materials (Basel), 2017 Jul 05;10(7).
    PMID: 28773110 DOI: 10.3390/ma10070756
    This paper remarks the general correlations of the shape and crystallinity of titanium dioxide (TiO₂) support on gold deposition and carbon monoxide (CO) oxidation. It was found that due to the larger rutile TiO₂ particles and thus the pore volume, the deposited gold particles tended to agglomerate, resulting in smaller catalyst surface area and limited gold loading, whilst anatase TiO₂ enabled better gold deposition. Those properties directly related to gold particle size and thus the number of low coordinated atoms play dominant roles in enhancing CO oxidation activity. Gold deposited on anatase spheroidal TiO₂ at photo-deposition wavelength of 410 nm for 5 min resulted in the highest CO oxidation activity of 0.0617 mmol CO/s.gAu (89.5% conversion) due to the comparatively highest catalyst surface area (114.4 m²/g), smallest gold particle size (2.8 nm), highest gold loading (7.2%), and highest Au⁰ content (68 mg/g catalyst). CO oxidation activity was also found to be directly proportional to the Au⁰ content. Based on diffuse reflectance infrared Fourier transform spectroscopy, we postulate that anatase TiO₂-supported Au undergoes rapid direct oxidation whilst CO oxidation on rutile TiO₂-supported Au could be inhibited by co-adsorption of oxygen.
    Matched MeSH terms: Fourier Analysis
  11. Fulltext Antibacterial performance of Ag nanoparticles and AgGO nanocomposites prepared via rapid microwave-assisted synthesis method
    Chook SW, Chia CH, Zakaria S, Ayob MK, Chee KL, Huang NM, et al.
    Nanoscale Res Lett, 2012;7(1):541.
    PMID: 23020815 DOI: 10.1186/1556-276X-7-541
    Silver nanoparticles and silver-graphene oxide nanocomposites were fabricated using a rapid and green microwave irradiation synthesis method. Silver nanoparticles with narrow size distribution were formed under microwave irradiation for both samples. The silver nanoparticles were distributed randomly on the surface of graphene oxide. The Fourier transform infrared and thermogravimetry analysis results showed that the graphene oxide for the AgNP-graphene oxide (AgGO) sample was partially reduced during the in situ synthesis of silver nanoparticles. Both silver nanoparticles and AgGO nanocomposites exhibited stronger antibacterial properties against Gram-negative bacteria (Salmonella typhi and Escherichia coli) than against Gram-positive bacteria (Staphyloccocus aureus and Staphyloccocus epidermidis). The AgGO nanocomposites consisting of approximately 40 wt.% silver can achieve antibacterial performance comparable to that of neat silver nanoparticles.
    Matched MeSH terms: Fourier Analysis
  12. Fulltext Biosorption Potential of Bacillus salmalaya Strain 139SI for Removal of Cr(VI) from Aqueous Solution
    Dadrasnia A, Chuan Wei KS, Shahsavari N, Azirun MS, Ismail S
    Int J Environ Res Public Health, 2015 Dec;12(12):15321-38.
    PMID: 26633454 DOI: 10.3390/ijerph121214985
    The present study investigated the biosorption capacity of live and dead cells of a novel Bacillus strain for chromium. The optimum biosorption condition was evaluated in various analytical parameters, including initial concentration of chromium, pH, and contact time. The Langmuir isotherm model showed an enhanced fit to the equilibrium data. Live and dead biomasses followed the monolayer biosorption of the active surface sites. The maximum biosorption capacity was 20.35 mg/g at 25 °C, with pH 3 and contact time of 50 min. Strain 139SI was an excellent host to the hexavalent chromium. The biosorption kinetics of chromium in the dead and live cells of Bacillus salmalaya (B. salmalaya) 139SI followed the pseudo second-order mechanism. Scanning electron microscopy and fourier transform infrared indicated significant influence of the dead cells on the biosorption of chromium based on cell morphological changes. Approximately 92% and 70% desorption efficiencies were achieved using dead and live cells, respectively. These findings demonstrated the high sorption capacity of dead biomasses of B. salmalaya 139SI in the biosorption process. Thermodynamic evaluation (ΔG⁰, ΔH⁰, and ΔS⁰) indicated that the mechanism of Cr(VI) adsorption is endothermic; that is, chemisorption. Results indicated that chromium accumulation occurred in the cell wall of B. salmalaya 139SI rather than intracellular accumulation.
    Matched MeSH terms: Fourier Analysis
  13. Fulltext Forensic analysis of accelerant on different fabrics using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and chemometrics techniques
    Farah Izza Jais, Sharifah Mastura, Naji Arafat Mahat, Dzulkiflee Ismail, Muhammad Naeim Mohamad Asri
    Malaysian Journal of Medicine and Health Sciences, 2020;16(2):112-117.
    MyJurnal
    Introduction: Accelerants and fabrics are commonly used to spread fire attributable to their highly flammable prop- erties. Hence, having the ability to discriminate the different types of accelerants on various types of fabrics after fire and/or arson using the non-destructive Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spec- troscopy coupled with chemometric techniques appears forensically relevant. Methods: Six types of fabrics viz. cotton, wool, silk, rayon, satin, and polyester, were burnt completely with RON95 and RON97 gasoline as well as diesel. Subsequently, the samples were analyzed by ATR-FTIR spectroscopy followed by Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) for discriminating the different types of accelerants on such burned fabrics. Results: RON95 showed the fastest rate of burning on all fabric types. Results also revealed that while wool had the slowest burning rate for all the three different accelerants, polyester, cotton, and satin demon- strated the highest rate of burning in RON95, RON97, and diesel, respectively. FTIR spectra revealed the presence of alkane, alcohol, alkene, alkyne, aromatic, and amine compounds for all fabrics. The two dimensional PCA (PC1 versus PC2) demonstrated 71% of variance and it was improved by cross-validation through the three dimensional LDA technique with correct classification of 77.8%. Conclusion: ATR-FTIR spectroscopy coupled with chemometric techniques had enabled identification of the functional groups, as well as statistically supported discrimination of the different accelerants, a matter of relevance in forensic fire and arson investigations.
    Matched MeSH terms: Fourier Analysis
  14. Characterization of Microcrystalline Cellulose Isolated from Conocarpus Fiber
    Fouad H, Kian LK, Jawaid M, Alotaibi MD, Alothman OY, Hashem M
    Polymers (Basel), 2020 Dec 07;12(12).
    PMID: 33297332 DOI: 10.3390/polym12122926
    Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.
    Matched MeSH terms: Fourier Analysis
  15. Fulltext Estimation of Caffeine Content in Coffee of Malaysian Market Using Fourier Transform Infrared (FTIR) Spectroscopy
    Francis Davin Nyoro, Siong Fong Sim, Amelia Laccy Jeffrey Kimura
    Trends in Undergraduate Research, 2018;1(1):0-0.
    MyJurnal
    This study reports the caffeine content in seven locally available coffee. The caffeine was extracted with chloroform and analysed using Fourier Transform Infrared (FTIR). The method reports an average recovery of 101% with the limit of determination established at 0.1%. The absorption band at 1654 cm-1 was used to construct the calibration curve for quantification of caffeine where the regression was fitted with satisfactory linearity. An average of 0.55% of caffeine was detected in the seven coffee products with Arabica coffee demonstrating lower caffeine concentration. The study evidenced that caffeine content in coffee is determined by the coffee types. The caffeine content found in the local coffee products was relatively lower likely due to the solvent types, extraction procedure and analytical method used.
    Matched MeSH terms: Fourier Analysis
  16. Contactless respiration rate measurement using optical method and empirical mode decomposition
    Gan KB, Yahyavi ES, Ismail MS
    Technol Health Care, 2016 Sep 14;24(5):761-8.
    PMID: 27163300 DOI: 10.3233/THC-161161
    BACKGROUND: At the emergency triage center, assessment of the present of the danger signs and measurement of vital signs are measured according to the guidelines. The respiration rate is still posing a challenge to the doctor as it is impractical to use conventional devices. Attaching measurement devices to the patient will induce artificial measurements (self-awareness stress effects) besides being time-consuming. Currently, the medical officers visually count the number of times the chest movement in a minute, sometimes poses cultural challenges especially for female patients.

    OBJECTIVE: The main objective of this paper is to develop a robust algorithm to extract respiration rate using the contactless displacement sensor.

    METHODS: In this study, chest movements were used as an indicative of inspiration and expiration to measure respiratory rate using the contactless displacement sensor. The contactless optical signals were recorded from 32 healthy subjects in four different controlled breathing conditions: rest, coughing, talking and hand movement to obtain the motion artifacts that the patients may have in the emergency department. The Empirical mode decomposition (EMD) algorithm was used to derive continuous RR signal from the contactless optical signal.

    RESULTS: The analysis showed that there is a good correlation (0.9702) with RMSE of 0.33 breaths per minutes between the contact respiration rate and contactless respiration rate using empirical mode decomposition method.

    CONCLUSION: It can be concluded that the empirical mode decomposition method can extract the respiration rate of the contactless optical signal from chest movement.

    Matched MeSH terms: Fourier Analysis
  17. Synthesis of kenaf cellulose carbamate using microwave irradiation for preparation of cellulose membrane
    Gan S, Zakaria S, Chia CH, Kaco H, Padzil FN
    Carbohydr Polym, 2014 Jun 15;106:160-5.
    PMID: 24721064 DOI: 10.1016/j.carbpol.2014.01.076
    Cellulose carbamate (CCs) was produced from kenaf core pulp (KCP) using microwave reactor-assisted method. The effects of urea concentration and reaction time on the formation of nitrogen content in CCs were investigated. The CCs' solubility in LiOH/urea system was determined and its membranes were characterized. As the urea content and reaction time increased, the nitrogen content form in CCs increased which enhanced the CCs' solubility. The formation of CCs was confirmed by Fourier transform infrared spectroscopy (FT-IR) and nitrogen content analysis. The CCs' morphology was examined using Scanning electron microscopy (SEM). The cellulose II and crystallinity index of the membranes were confirmed by X-ray diffraction (XRD). The pore size of the membrane displayed upward trend with respect to the urea content observed under Field emission scanning electron microscope (FESEM). This investigation provides a simple and efficient procedure of CCs determination which is useful in producing environmental friendly regenerated CCs.
    Matched MeSH terms: Fourier Analysis
  18. Fulltext Novel chemical synthesis and characterization of copper pyrovanadate nanoparticles and its influence on the flame retardancy of polymeric nanocomposites
    Ghiyasiyan-Arani M, Masjedi-Arani M, Ghanbari D, Bagheri S, Salavati-Niasari M
    Sci Rep, 2016 05 04;6:25231.
    PMID: 27143312 DOI: 10.1038/srep25231
    In this work, copper pyrovanadate (Cu3V2O7(OH)2(H2O)2) nanoparticles have been synthesized by a simple and rapid chemical precipitation method. Different copper-organic complexes were used to control the size and morphology of products. The morphology and structure of the as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrum, electron dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), differential thermal analysis (DTA) and photoluminescence (PL) spectroscopy. The influence of copper pyrovanadate nanostructures on the flame retardancy of the polystyrene, poly vinyl alcohol and cellulose acetate was studied. Dispersed nanoparticles play the role of a magnetic barrier layer, which slows down product volatilization and prevents the flame and oxygen from the sample during decomposition of the polymer. Cu3V2O7(OH)2(H2O)2 is converted to Cu3V2O8 with an endothermic reaction which simultaneously releases water and decrease the temperature of the flame region.
    Matched MeSH terms: Fourier Analysis
  19. Fulltext Hydrothermal preparation of silver telluride nanostructures and photo-catalytic investigation in degradation of toxic dyes
    Gholamrezaei S, Salavati-Niasari M, Ghanbari D, Bagheri S
    Sci Rep, 2016;6:20060.
    PMID: 26805744 DOI: 10.1038/srep20060
    Different morphologies of Ag2Te nanostructures were synthesized using TeCl4 as a new precursor and hydrazine hydrate as reducing agent by a hydrothermal method. Various parameters that affect on morphology and purity of nanostructures were optimized. According to our experiments the best time and temperature for preparation of this nanostructure are 12 h and 120 °C. The photo-catalytic behaviour of nanostructures in presence of UV-visible light for degradation of methyl orange was investigated. Results show that the presence of UV light is necessary for an efficient degradation of dye in aqueous solution. On the other hand, as observations propose the Ag2Te reveal a strong photoluminescence peak at room temperature that could be attributed to high level transition in the semiconductor. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) techniques and UV-visible scanning spectrometer (UV-Vis).
    Matched MeSH terms: Fourier Analysis
  20. Effects of Rf power on structural properties of Nc-Si:h thin films deposited by layer-by-layer (LBL) deposition technique
    Goh BT, Muhamad Rasat Muhamad, Saadah Abdul Rahman
    Sains Malaysiana, 2012;41:993-1000.
    The effects of rf power on the structural properties of hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited using layer-by-layer (LbL) deposition technique in a home-built plasma enhanced chemical vapor deposition (PECVD) system were investigated. The properties of the films were characterized by X-ray diffraction (XRD), microRaman scattering spectroscopy, high resolution transmission electron microscope (HRTEM) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the films consisted of different size of Si crystallites embedded within an amorphous matrix and the growth of these crystallites was suppressed at higher rf powers. The crystalline volume fraction of the films was optimum at the rf power of 60 W and contained both small and big crystallites
    with diameters of 3.7 nm and 120 nm, respectively. The hydrogen content increased with increasing rf power and enhanced the structural disorder of the amorphous matrix thus decreasing the crystalline volume fraction of the films. Correlation of crystalline volume fraction, hydrogen content and structure disorder of the films under the effect of rf
    power is discussed.
    Matched MeSH terms: Fourier Analysis
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