IZTECH Research Centers Collection / İYTE Araştırma Merkezleri Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11147/2636
Browse
8 results
Search Results
Article Citation - WoS: 17Citation - Scopus: 16Synthesis, Characterization and Adsorption Studies of Phosphorylated Cellulose for the Recovery of Lithium From Aqueous Solutions(Editura Acad Romane, 2021) Recepoğlu, Yaşar Kemal; Yüksel, AslıIn this study, pristine cellulose was functionalized by the phosphorylation reaction to make it suitable for lithium separation. After characterization studies of the synthesized adsorbent with SEM, EDX, FTIR, TGA and XPS, the effects of various parameters on the lithium uptake capacity of the adsorbent were examined. The analysis of equilibrium data by several adsorption models showed that maximum adsorption capacity of the adsorbent was found to be 9.60 mg/g at 25 degrees C by the Langmuir model. As initial concentration and contact time increased, adsorption capacity also increased, however, mild temperature (25-35 degrees C) and pH (5-6) were better for the adsorption of lithium. 80% of lithium adsorption within three minutes proved the fast kinetic nature of the adsorbent. A 99.5% desorption efficiency of lithium was achieved with 0.5 M H2SO4, among HCl and NaCl with different molarities. Phosphorylated cellulose was shown to be a favorable adsorbent for the recovery of lithium from aqueous solutions.Conference Object Citation - Scopus: 1Enterprise Systems Applications Development Plans To Build and Develop Robust and Environmentally Sensitive Green Logistics Systems Management Software(Springer Verlag, 2009) Yıldız, Türkay; Yercan, FundaWithin the concept of enterprise-wide development of environmentally sensitive systems' application modules to fully integrate all-in-one green logistics services principles have received much attention and consideration from practitioners, academia, and from the industry, for about more than a decade. However, by taking into the consideration of the multidisciplinary nature of the issue, large scale effective collaborative framework is needed to be developed. Therefore, utilization of UML diagrams, class definitions, defining class relationships, fields, tables, views, etc. so on play crucial roles in the design phases of the enterprise system. Thus, this article largely deals with the major logistics work processes and their interactions within the consideration of environmental engineering issues on business operations to address step-by-step process control mechanisms to provide necessary input to build robust-design and better implementation of the needed IT software backbone.Article Citation - WoS: 9Citation - Scopus: 13X-Ray Fluorescence Spectroscopic Determination of Heavy Metals and Trace Elements in Aerial Parts of Origanum Sipyleum L From Turkey(Pharmacotherapy Group, 2016) Durmuşkahya, Cenk; Alp, Hakan; Hortooğlu, Zehra Sinem; Toktaş, Ümit; Kayalar, HüsniyePurpose: To determine the heavy metal and trace element composition of the powdered aerial parts of Origanum sipyleum L. and its water extract. Methods: The heavy metal and trace elements content of the powdered plant material and 2% aqueous extract were evaluated by x-ray fluorescence spectroscopy with silicon drift detector SDD at a resolution of 145 eV and 10,000 pulses. The process conditions were 0.1 g sample weight, process time of 300 s at a voltage of 25 kV and 50 kV, and at a current of 0.5 and 1.0 mA under helium atmosphere. Results: The major elements, K, Ca and Na, known as macronutrients, constituted 11990, 10490 and 970 ppm of the powdered drug and 8910, 2991 and 810 ppm of the water extract, respectively. Among other constituents, arsenic, lead and uranium levels were < 1, 2.1 and < 3 ppm, respectively, in the powdered material while in the aqueous extract, the levels were < 1, < 2 and 200 ppm, respectively. Conclusion: O. sipyleum is a potential source of macro- and micronutrients from which useful food additives and health supplements can be derived.Article Citation - Scopus: 1Prognostic Significance of the Igvh Mutation Status and Immunohistochemical Analysis of Zap70 and Cd38 in Bone Marrow Biopsies in Chronic Lymphocytic Leukemia(Türkiye Klinikleri Journal of Medical Sciences, 2014) Kahraman Çetin, Nesibe; Kaçar Döger, Füruzan; Kurtgöz, Serkan Erkan; Rusçuklu, Dane; Yavaşoğlu, İrfanObjective: Chronic lymphocytic leukemia (CLL) is one of the most common leukemia type among adults in the industrialized countries. Due to the nature of CLL, it is important to recognize patients with a more rapid course of disease. The goal of our study was to study ZAP70 and CD38 antibodies along with immunglobulin heavy chain variable region (IgVH) mutation status, which have been associated with rapid progression and aggressive clinical course in CLL, and to correlate the expression of these molecules with patterns of bone marrow infiltration. Material and Methods: We included 84 bone marrow biopsy samples into the study to determine ZAP70 and CD38 status using immunohistochemistry. Expression patterns for both antibodies were then correlated with the bone marrow infiltration patterns. We also analyzed IgVH mutations in 20 patients using DNA obtained from paraffin-embedded formalin-fixed bone marrow biopsies. These findings were then correlated with immunohistochemical results. Results: We identified a positive correlation between the expression patterns of ZAP70 and CD38, factors that were previously identified as poor prognostic factors (p<0.001). However, there was no correlation between these two markers and IgVH mutation status (p=1.000 and p=0.931). In addition, we showed a statistically significant positive correlation with ZAP70 immunostaining, and the necessity for an early intervention (p=0.046). ZAP70 and CD38 expressions were statistically significantly correlated with the diffuse pattern infiltration of bone marrow (p<0.001 and p<0.001, respectively). Conclusion: Despite small number of our patients, the findings of our study suggested that ZAP70 and CD38 expression patterns as well as IgVH mutation status might be helpful to determine the course of the disease, and the risk of progression. Particularly ZAP70 immunopositive patients appear to have a faster disease progression, and may require earlier intervention and a closer follow up.Article Citation - Scopus: 19Application of Geothermal Energy and Its Environmental Problems in Turkey(Inderscience Enterprises Ltd., 2015) Baba, AlperHuman beings have been benefiting from geothermal energy for different uses since the dawn of the civilisation in many parts of the world. One of the earliest uses of geothermal energy was for heating and it was used extensively by Romans in Turkey. The Aegean region is favoured by a large number of thermal springs known since ancient times. However, it was first in the 20th century that geothermal energy was used on a large scale for direct use and electricity generation. The country's installed heat capacity is 2,705 MWt for direct use and 322.39 MWe for power production. In parallel to developing geothermal energy applications in Turkey, many sites are now experiencing problems such as water contamination associated with geothermal fluid. Especially, the high temperature solution of elements and compounds, causes operational limitations in geothermal power plants. These limitations are due to the severe scaling and corrosion of geothermal fluid. Copyright © 2015 Inderscience Enterprises Ltd.Article Mineral Compositions of Some Selected Centaurea Species From Turkey(Chemical Publishing Co., 2014) Kayalar, Hüsniye; Durmuşkahya, Cenk; Hortooğlu, Zehra SinemCentaurea calolepis Boiss., Centaurea lydia Boiss. and Centaurea polyclada DC. were investigated for major minerals and trace elements by X-ray fluorescence spectrometry. Calcium and potassium were found in maximum concentrations in Centaurea species. The results revealed that the concentrations of iron, manganese and zinc were found to be high in C. calolepis. On the other hand, copper, magnesium and phosphorous were found in higher concentrations in C. polyclada. Mineral composition of Centaurea species, will be descriptive in terms of the traditional use of this species. In addition, C. calolepis, C. lydia and C. polyclada may be utilized in nutraceuticals as potential natural sources of major minerals and trace elements.Article Citation - WoS: 3Citation - Scopus: 7Elemental Analysis of Galium Incanum Sm Subsp Centrale Ehrend by X-Ray Fluorescence Spectroscopy(Pharmacotherapy Group, 2013) Kayalar, Hüsniye; Durmuşkahya, Cenk; Hortooğlu, Zehra SinemPurpose: To evaluate the content of trace elements in Galium incanum SM. subsp. centrale Ehrend. Methods: The air-dried aerial parts of the plant material were used and its water extract (2 % w/v infusion) was analysed for trace elements using x-ray fluorescence (XRF) spectrometry. Results: The aqueous extract depicted significant concentrations of macro- and micro-nutrients with heavy metal and metal oxide content of 4.07 - 6.02 and 3.19 - 4.01 % for powdered plant material and water extract, respectively. The contents of Ca (22840 ppm) and K (8204 ppm) were the highest among all the elements while Zn (45.9 ppm) and Fe (328 ppm) were also detected in significant amounts. Zn, Mn and Cu showed the highest content while those of Mg, Al, K, Ca, Fe and P lowest in the water extract. Conclusion: The presence of significant levels of Ca, K, Na, Fe, Zn, Mg, Mn and Cu in G. incanum subsp. centrale showed that this plant has notable nutrient elements. The traditional use of Gallium species as a diuretic may be attributed to its rich content of potassium.Article Citation - WoS: 20Citation - Scopus: 20Screening Virulence Properties of Staphylococci Isolated From Meat and Meat Products(B W K Public Relations, 2009) Sudağıdan, Mert; Aydın, A.Virulence properties (biofilm formation, antibiotic susceptibility, production of extracellular enzymes and the presence of toxin genes) of staphylococci isolated from various meat and meat products were investigated. 22 Staphylococcus spp. (S. aureus n = 9, S. haemolytlcus n = 4, S. cohnii n = 3, S. saprophytics n = 3, S. hominis n = 1, S. simulans n = 1 and S. warneri n = 1) were isolated from 120 meat and meat product samples. 10 strains were biofilmformers. Although none of the strains was resistant to vancomycin, oxacillin, teicoplanin, ofloxacin and gentamicin, 8 strains were found to be resistant to penicillin and one strain was found to be resistant to erythromycin. In addition, all strains were negative for the mecA PCR. 8 strains showed lipolytic activity against Tween 80,10 strains against Tween 20, and 18 strains against tributyrin. Moreover, 9 strains showed proteolytic activity against casein, 11 strains against milk and 17 strains against skim milk containing media. Mostly S. aureus strains showed positive results for icaA-SA, nuc, geh, sspA, sspB, aur, serine protease gene, hla, hlb, set1, and etb. However, 7 of coagulase-negative staphylococci strains were found to carry see gene. As both prevalence and concentration of this bacterium were low, and no isolate contained all virulence factors, it is concluded that common hygiene and process control measures should be sufficient to control meatborne staphylococcal intoxication.