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61.
Bushra Rashid Z. Leman M. Jawaid M. J. Ghazali M. R. Ishak 《Cellulose (London, England)》2016,23(5):2905-2916
Sugar palm fiber (SPF) is one of the prospective fibers used to reinforce polymer composites. The aim of this study is to evaluate the physicochemical, thermal, and morphological properties of SPF after alkali and sea water treatments. The chemical constituents group and thermal stability of the SPF were determined using scanning electronic microscopy (SEM) along with energy dispersive X-ray spectroscopy and thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy was carried out to detect the presence of functional groups in untreated and treated SPF. The SEM images after both treatments showed that the external surface of the fiber became clean as a result. However, the sea water treatment affected the fiber properties physically, while the alkali treatment affected it both physically and chemically by dissolving the hemicellulose in the fiber. The TGA results showed that untreated fiber is significantly more stable than treated fiber. In conclusion, the results show that the fiber surface treatment significantly affected the characterization of the fiber. 相似文献
62.
Ozsoz M Erdem A Ozkan D Kara P Karadeniz H Meric B Kerman K Girousi S 《Bioelectrochemistry (Amsterdam, Netherlands)》2005,67(2):199-203
Electrochemical DNA biosensors have become strong candidates for DNA based analysis. Allele-specific genotyping is also one of the important research areas, where electrochemical approaches provide promising advances. Recently reported two methods based on electrochemical guanine and colloidal gold (Au) nanoparticle oxidation signals are reviewed and compared with the existing genotyping methods in this report. 相似文献
63.
Kuang Leman 《International Journal of Theoretical Physics》1994,33(2):261-278
Complex contour integral techniques, developed in a previous paper for theN=0 and 1 superconformal theories on higher-genus Riemann surfaces, are applied to a Becchi-Rouet-Stora-Tyutin (BRST) quantization procedure of superconformal theories withN=2, 3, and 4 super-Krichever-Novikov (KN) constraint algebras on a genus-g Riemann surface. The BRST charges of the superconformai theories are constructed and the nilpotency of the BRST charges is checked. The critical spacetime dimension and the intercepts are found for theN=2 and 4 cases. Also calculated are the central charge and the intercept for theN=3 case. 相似文献
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65.
Preliminary picture of 137Cs radioactivity levels in forested areas in and around Izmir is illustrated. Both activity concentrations and activity depositions
of 137Cs in soil samples were determined. Their values varied from 8.29±0.27 to 445±3.16 Bq.kg−1 (d.w.) and 0.63±0.01 to 11.6±0.08 kBq.m–2 (d.w.), respectively. It was found that while activity deposition of 137Cs is normally distributed, activity concentration of 137Cs is log-normally distributed in forest soils and the activity deposition is less variable than the activity concentration.
Cesium-137 activities in soils increase with increasing elevation, annual average rainfall and soil organic matter. 相似文献
66.
Miraç Ocak Hakan Alp Halit Kantekin Hülya Karadeniz Ümmühan Ocak 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(1-2):17-24
Three new macrocyclic crown ether ligands containing nitrogen–oxygen donor atoms were designed and synthesized from 1,4-bis(2′-formylphenyl)-1,4-dioxabutane
and 4-nitro-o-phenylenediamine. Ion-pair extraction of metal picrates such as Ag+, Hg2+, Cd2+, Zn2+, Cu2+, Ni2+, Mn2+, Co2+, and Pb2+ from aqueous phase to the organic phase was carried out using the novel ligands. The solvent effect over the metal picrate
extractions was investigated at 25 ± 0.1 °C by using UV–visible spectrometry. The extractability and the values of the extraction
constants (log Kex) were determined for the extracted complexes. 相似文献
67.
The application of multiwalled carbon nanotube (MWCNT) based screen printed graphite electrodes (SPEs) was explored in this study for the electrochemical monitoring of DNA hybridization related to specific sequences on Hepatitis B virus (HBV) DNA. After the microscopic characterization of bare MWCNT‐SPEs and DNA immobilized ones was performed, the optimization of assay has been studied. The development of screen printing process combined with nanomaterial based disposable sensor technology leads herein a great opportunity for DNA detection using differential pulse voltammetry (DPV) by measuring the guanine oxidation signal observed at +1.00 V in the presence of DNA hybridization between HBV probe and its complementary, target. The detection limit estimated for signal to noise ratios =3 corresponds to 96.33 nM target concentration in the 40 μL samples. The advantages of carbon nanotube based screen printed electrode used for electrochemical monitoring of DNA hybridization are discussed with sensitivity, selectivity and reproducibility in comparison with previous nanomaterial based electrochemical transducers developed for DNA or other biomolecular recognitions. 相似文献
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70.
DPPH, superoxide and nitric oxide radical scavenging activities and total phenolic content (TPC) of some less known plants, distributed in Burdur-Antalya provinces and consumed both as food and for the medicine, Asplenium ceterach L. (golden herb), Valeriana dioscoridis Sm. (valerian), Doronicum orientale Hoffm. (tiger herb), Cota pestalozzae (Boiss.) Boiss. (camomile), Eremurus spectabilis M. Bieb. (foxtail lily), Asphodeline lutea (L.) Rchb. (asphodel) and Smyrnium connatum Boiss. and Kotschy (hemlock) were investigated. As a result, the highest 2,2-diphenyl-1-picril hydrazyl (DPPH) radical scavenging activity was determined in C. pestalozzae extract (IC50 = 18.66 μg mL? 1), the highest superoxide and nitric oxide radical scavenging activity was determined in A. ceterach extract (IC50 = 145.17 and 372.03 μg mL? 1). The highest TPC was determined in A. ceterach extract (59,26 μg mL? 1) as gallic acid equivalent. Further bioactivity and phytochemistry studies on these plants may enlighten new drug discovery researches. 相似文献