Browsing by Author "Memon, N"

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    Comparative Analyses of Few West Turkish Varieties of Pomegranate (Punica granatum L.) Peels for Phenolic Content Using Liquid Chromatography
    Yenil, N; Yemies, F; Sabikoglu, I; Memon, N; Güler, A
    In this work, the amounts of phenolic compounds in the peels of four different pomegranate varieties grown in ozdere-Izmir, Turkey were investigated for the first time. Three different extraction processes namely reflux, ultrasonic bath and mixing, were carried out with dry and fresh pomegranate peels for two different periods of 4 and 12 h. The best results for ellagic acid, hesperidin, and quercetin, except resveratrol, were observed in refluxing extraction in MeOH. It is seen that the amounts of ellagic acid obtained from the dry samples are quite good in shorter extraction time (4-h) as 2778, 3376, 5024 and 3115 mu g/g, when compared to fresh samples where reduced amounts were obtained as 973, 2046, 3232 and 1822 mu g/g. Similarly, the highest ellagic acid quantities were observed in dry and fresh samples as named of Izmir 8; 2624 mu g/g and 8761 mu g/g, respectively by using HPLC-DAD for longer extraction time (12-h) which was found to negatively affect the phenolics for fresh samples. In fresh samples, extraction is rapid and long heating causes deterioration. As expected, the amount of ellagic acid was higher in the dry ones. The flavonoids hesperidin and quercetin were detected in quite well amounts for most of the samples, also hesperidin was in high as about 85.5 and 73.3 mu g/g in one of the samples. Fifteen different phenolics such as ellagic acid, hesperidin, quercetin, resveratrol, catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, cyanidin, delphinidin, malvidin, myricetin, caffeic acid, caftaric acid, p-coumaric acid, gallic acid and ferulic acid were investigated. The antioxidant activity and total phenolic content analyses were also conducted in the methanolic supernatant extracts. DPPH inhibitions of all extracts varied from 47.22% to 93.83% at 4-h and from 36.88% to 94.96% at 12-hour extractions. Furthermore, ANOVA analyzes for ellagic acid and some catechin derivatives was conducted.
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    Carbon Based Electrode Materials and their Architectures for Capacitive Deionization
    Samejo, B; Gul, S; Samejo, S; Abro, NQ; Yenil, N; Memon, N
    The effective desalination and purification devices for seawater/ brackish water treatment are crucial in sustainable progress. Techniques that render high salt removal efficiency and water purification ability at low applied potentials play a central role in sustainable water supplies. One of them is capacitive deionization (CDI) which has drawn significant consideration as a promising deionization technology since the last decade. Desalination efficiency profoundly depends on tie utilized electrode material. The most widely used CDI electrodes are carbons due to their cost effectiveness and good stability. However, to acquire high electrosorption capacity, extensive researches are reported with modified carbon materials. CDI cell architectures are equally important for practical high salt removal performance. This review focuses on carbon materials in CDI along with other emerging trends in diverse carbon types, e.g., carbon nanotubes and their composites. Various architectures reported in the literature to improve desalination efficiency are also included here.