Browsing by Author "Alkan, S."

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Adsorption Equilibrium and Thermodynamics of Diatomite (çaldiran/Van) Onsome Textile Dyes
(Chemical Society of Pakistan, 2018) Alkan, S.; Calişkan, M.; Irende, İ.; Kul, A.R.
Together with increasing world population, developing technology and rapid industrialization process bring about environmental pollution. Nowadays, cleaning environment from industrial wastes and pollutants is of utmost importance. Some organic materials, produced by the majority of textile waste, cause environmental pollution. Many dyestuffs, which are hazardous for environment, can be released to environment by industrial organizations without having any precaution. Textile dyestuffs, being above certain concentrations, can cause poisoning of aquatic organisms. Dyestuffs can be classified as following: Anionic: Direct, acid and reactive dyes Cationic: Basic dyes Nonionic: Disperse dyes It can be said that most problematic group of dyes used in the textile industry is the group of reactive dyes. Analyzing performed studies shows that these views are supported. Today, adsorption techniques are gaining ground due to efficiency in removal of too stable pollutants. Adsorption is, economically, a reasonable method and we can say that it provides formation of high quality products. With the development of industry search for materials, to be used as adsorbent for removal of factory wastes and water-soluable dyestuffs from water, accelerates. In our study, from natural adsorbents diatomite(Çaldıran/VAN) is used as an adsorbent material. The removal of natural red and basic blue from aqueous solution using diatomite, was investigated with respect to the adsorbent dose (0,02 g), initial concentration (20-140 mg/L), temperature (between 25 and 450C), on batch adsorption were studied as a function of contact time. The lineer Langmuir, Freundlich and Temkin adsorption equations were applied to describe the equilibrium isotherms. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (ΔH0), Gibbs free energy (ΔG0) and entropy (ΔS0) shoved spontaneous and endothermic in nature of adsorption for both of adsorbents. Copyright © 2018 Chemical Society of Pakistan. All Rights Reserved.
Adsorption of Basic Blue 41 Using Juniperus Excelsa: Isotherm, Kinetics and Thermodynamics Studies
(Yildiz Technical University, 2019) Kul, A.R.; Aldemir, A.; Alkan, S.; Elik, H.; Caliskan, M.
In this study Juniperus excelsa shavings powder (JESP) was utilized as an adsorbent for the removal of Basic Blue 41 (BB 41) which is one of the common basic dyes, from aqueous solution. The adsorption experiments were carried out in a batch system and effects of initial concentration of dye, interaction time and temperature were investigated. Langmuir, Freundlich and Temkin adsorption isotherms were used to model equilibrium data. According to the results, Freundlich isotherm model becomes more convenient option compared with Langmuir and Temkin models. Freundlich model coefficients are raise as the temperature rises, showing that the adsorption process becomes favorable higher temperature. The kinetic parameters were determined by pseudo first order (PFO), pseudo second order (PSO) and intra-particle diffusion (IPD) models. Results indicated that experimental and calculated qe values are matched to each other. Thus the process fits PSO kinetic model with higher R2 values than other two models. Kinetic constants become closer to both temperatures and initial concentrations and qe values are increases with increasing concentration of BB 41. Initial dye concentration elevates from 25 to 100 mg L-1, dye adsorption capacity onto JESP from 3.06 to 16.53 mg g-1, respectively. Thermodynamic parameters for instance free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were assessed. Enthalpy and entropy of this separation process are determined from 3081.91 J mol-1 and 12.33 kJ mol-1, respectively. The negative values of ΔG° showed that this separation process was endothermic and natural. The research results demonstrate that JESP may be a substitute than pricey adsorbents for dye removal. © 2019 Yildiz Technical University. All rights reserved.
A Bibliometric Analysis on Dicrocoelium Dendriticum
(Tehran University of Medical Sciences, 2023) Kiliç Altun, S.; Barlik, F.; Aydemir, M.E.; Alkan, S.
Background: Dicrocoelium dendriticum, a worldwide zoonotic trematode, is a common parasite of ruminant animals, but humans can be the definitive host by chance. We analyzed the world situation of the parasite from the perspective of the One Health concept by analyzing the research literature published from 1931 to 2022. Methods: Published documents related to D. dendriticum were searched from the Scopus database. Focusing on a visual analysis of the main research documents on D. dendriticum, Dimensions free web app was used to conduct co-occurrence analysis with keywords, countries, institutions, and authors. Moreover, key clustering research, affiliaitons, journals, countries, and authors were determined. Results: The Higher Council for Scientific Research (CSIC) was the most publishing affiliation on D. dendriticum with 19 articles. While the Veterinary Parasitology Journal was the mostly publishing journal on D. dendriticum with 38 articles, the most productive country was Iran. The authors Giuseppe Cringoli and Laura Rinaldi from Università degli Studi di Napoli Federico II, Naples, Italy were the mostly publishing authors. Conclusion: This bibliometric analysis provides an overall description of the current state of D. dendriticum research and the initial exploration of future research directions. Our analysis provides guidance for the development of research on D. dendriticum. © 2023 Altun et al. Published by Tehran University of Medical Sciences.
Bibliometric Assessment of Thelaziosis Research in Europe From 1970-2023
(University of Tabriz, 2023) Tahmaz, A.; Alkan, S.; Aydemir, S.
Given the increase in cases of thelaziosis in recent years, especially in Europe, we evaluate the publication patterns of research focusing on Thelazia. We also discuss the results of published articles and how more clinical and epidemiological information on Thelazia is still needed. All the documents registered in Web of Science with the subject of Thelazia between 1970 and 31 March 2023 were analyzed, using the Online Analysis Platform of Literature Metrology and the VOS viewer as tools. Between 1970 and March 2023, there were 336 publications on Thelazia. During the same period, these documents were mentioned 5597 times, averaging 16.66 times for each record. Thelazia's first publications appeared in 1970, and 55.95% of all publications were published after 2010. Regarding total publication numbers, the most influential country was Italy (n = 87), followed by the United States (n=57). The most prolific author in this field was "Domenico Otranto" (n = 77), while the journals that drew the most papers were Parasites & Vectors (n = 30) and Veterinary Parasitology (n = 29). The findings of this article will be useful in defining research priorities related to Thelazia and diagnosing the importance of scientific production associated with this pathogen. © 2023, Published by University of Tabriz.
Dissolution Kinetics of Thermally Dehydrated Colemanite in Perchloric Acid Solutions
(Asian Journal of Chemistry, 2008) Kubilay, S.; Yalcinkaya, Z.; Alkan, S.; Savran, A.
In this study, the dissolution of thermally dehydrated colemanite in aqueous perchloric acid solutions was investigated in a batch reactor employing the parameters of solid to liquid ratio particle size, temperature and acid concentration. It was found that the dissolution rate increased with increasing temperature and acid concentration, decreasing particle size and solid to liquid ratio. No important effect of stirring speed was observed, The dissolution kinetics of colemanite was examined according to heterogeneous and homogeneous reaction models and it was found that the dissolution rate was controlled by heterogeneous chemical reaction. The activation energy of the process was determined to be 41.07 kJ mol(-1). The experimental data were tested by graphical and statistical methods and it was found that the following model best fit the experimental data 1 - (1 -X)(1/3) = 7.56 x 10(5) (Rp)-0.1076 x (C-Lambda)0.4629 x (S/L) - 0.2525 x e(-4938) x t.
Erratum: Effects of Some Drugs on Enzyme Activity of Catalase From Bovine Liver (Asian Journal of Chemistry (2006) 18, 1 (601-607))
(Chemical Publishing Co., 2006) Alkan, S.; Savran, A.; Demir, H.; Ceylan, H.
Immobilization of Catalase Via Adsorption Into Natural and Modified Active Carbon Obtained From Walnut in Various Methods
(Academic Journals, 2009) Alkan, S.; Gur, A.; Ertan, M.; Savran, A.; Gur, T.; Genel, Y.
In the present work, the immobilization of catalase into natural active carbon and active carbon modified by hydrochloric acid was carried out. In the experimental section, the effects of pH, ionic strength and reaction temperature were chosen as parameters, with experiments performed in batch system. For the optimization of immobilization procedure, values of kinetic parameters were evaluated. It was observed that storage and operational stabilities of the enzyme increased with immobilization. The results obtained from experiments showed that active carbon is a valuable support for the adsorption of enzymes.
Immobilization of Catalase Via Adsorption Onto Natural and Modified Montmorillanit Analsim-Clay
(Polish Chemical Soc, 2009) Alkan, S.; Gur, T.; Gur, A.; Uruc, H.; Demir, H.
Immobilization of the enzyme catalase on natural and modified montmorillanit analsim-clays was investigated using a batch system. Such an immobilization does not result in enzyme inactivation and constitutes a valuable method for immobilizing catalase at high ionic strength. In the immobilization process, the effect of pH, ionic strength and reaction temperature were chosen as parameters. Furthermore the optimization of immobilization conditions were studied using data obtained from experimental results. For the free catalase and three different immobilized catalase enzymes, the optimum pH values 8, 7, 7 and 8; reaction temperature 30 degrees C; ionic strength 0.25 M were found. It was determined that enzyme activity for enzyme supported by natural clay was 73.3%, when it was retained during the storage at 4 degrees C for a period of 60 days. It was observed that storage and operational stabilities of the enzyme increased with immobilization. The results obtained show that montmorillanit analsim-clay is valuable and favourable support the simple adsorption of enzymes.
Investigation of Publication Trends and Hot Topics on Onchocerciasis Between 2000 and 2022
(University of Tabriz, 2023) Alkan, S.; Gürbüz, E.; Aydemir, S.
This study aimed to use bibliometric tools to investigate onchocerciasis research conducted worldwide between 2000 and 2022. This bibliometric study was carried out using the Scopus database. The analysis unit was the documents conducted on onchocerciasis between 2000 and 2022. The data obtained after the last evaluations were transferred to VOSviewer (VOSviewer 1.6.19 for Microsoft Windows systems) and biblioshiny (bibliometrix R package) programs for analysis. The present results showed that 1026 documents on onchocerciasis were indexed in the Scopus database between 2000 and 2022. 2554 authors have published this literature, and the annual growth rate was 1.34 %. Forty-one articles were published in 2000, and after 2014, there was an increase in the number of articles. The most publications were published in 2018 (n = 82). PLOS Neglected Tropical Diseases (n = 97) and Parasites & Vectors (n = 46) published the most publications on onchocerciasis. Most of the publications were published by authors from the United States (n = 341), the United Kingdom (n = 228), Cameroon (n = 150), Nigeria (n = 132), and Germany (n = 120). The documents originating from the United States (n = 2372) had the highest citation numbers. The onchocerciasis research landscape between 2000 and 2022 is outlined in this report. Furthermore, the analysis offers an enhanced comprehension of the trends in onchocerciasis development over the previous 23 years, which might serve as a scientific benchmark for subsequent research. © 2023, Published by University of Tabriz.
Trends in Anisakis Simplex Global Research: a Bibliometric Analysis Study
(Galenos Publishing House, 2024) Aydemir, M.E.; Aydemir, S.; Kılıç Altun, S.; Alkan, S.
Objective: Anisakis simplex is a fish-borne zoonotic parasite. Although this parasite has been known since the 19th century, publications on anisakiasis have increased in recent years. Despite this, this subject has yet to be well studied by bibliometric analysis. This study was conducted to show the research points and trends of A. simplex. Methods: The Web of Science Core Collection (WoSCC) was mined for articles on A. simplex. The VOSviewer software visually evaluated countries, institutions, authors, references, and keywords in this field. Results: A total of 1362 publications were included in this bibliometric analysis. The included publications were published between 1970 and 2022 from 79 countries, mainly from Spain (n=456, 33.48%). The most prolific year was 2020 (n=74). The research area that attracted the most publications was parasitology (n=452), while the most productive author in this area was Cuellar C (n=53). “Anisakis simplex”, “Anisakis” and “anisakiasis” were the most used three keywords. Conclusion: The number of publications on anisakiasis has been increasing over time, suggesting that A. simplex is becoming an increasingly important disease worldwide. Research cooperation should be established between researchers from developed and developing countries to determine effective control strategies for anisakiasis. © 2024 Turkish Society for Parasitology.