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Now showing 1 - 10 of 266
  • Article
    Citation - WoS: 13
    Citation - Scopus: 16
    An Analytic Network Process Based Risk Assessment Model for Ppp Hydropower Investments
    (Vilnius Gediminas Tech Univ, 2021) Akcay, Emre Caner
    The number of public-private partnership (PPP) projects has gone up especially in developing countries. The risk assessment of PPP projects is essential in ensuring project success. The objective of this study is to develop an Analytic Network Process (ANP) based risk assessment model for hydropower investments, and a tool to facilitate quantification of risk ratings based on this model. The results show that the three most important risk factors that affect the overall risk rating of a PPP hydropower investment are legal risks, contractor/subcontractor risks, and operator risks. In addition, the three most important risk clusters were identified as stakeholders, government requirements, and resources, whereas market was the least important cluster. The tool that measures the risk rating of a PPP of hydropower project was tested on ten real cases, and satisfactory results were obtained in terms of its predictive capability. The contributions of this research include (1) identification of the risk factors and clusters of factors associated with PPP hydropower investments; (2) determination of the priority of each risk factor and cluster; (3) development a tool that guides the investors through the risk assessment of PPP hydropower investments.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 18
    Metagenomic and Chemical Analysis of Tarhana During Traditional Fermentation Process
    (Elsevier, 2021) Soyucok, Ali; Yurt, Mediha Nur Zafer; Altunbas, Osman; Ozalp, Veli Cengiz; Sudagidan, Mert
    Tarhana is one of the favourable traditional fermented food consumed as a soup. Different flour, vegetables, spices and yogurt are main constituents and they compose of microbiota of Tarhana. In this study, bacterial communities in each fermentation process and in their constituents were identified by metagenomic analysis. Also, chemical properties (pH, acidity, salt content and dry matter) were analysed in each step. The results showed that in the dough formation, mainly Lactobacillus, Bacillus, Enterococcus and Streptococcus were present and after Day 4, Clostridium and Bacillus became dominant, after drying Clostridium disappeared and in the final product bacterial communities from Bacillus and Streptococcus genus were observed. Chemical analysis showed that pH decreased from 4.94 to 4.46, acidity increased by time at the beginning of fermentation from 7.5% to 22.5% in first 6 days period, then, became stable at 14% in drying process. Salt content increased by time from 1.74 to 3.08 g salt/100 g Tarhana in first 8 days and in drying process salt content was recorded as 2.81-2.90 and dry matter was obtained as 94 g dry matter/100 g Tarhana in the final product. This study elucidated the effects of ingredients, raw materials and how microbiota and chemical properties changes during fermentation steps of home-made traditional Tarhana production and thus preparation methods could be developed to obtain standardized Tarhana products for industrial production in future.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 7
    Clinical Characteristics of Patients With Intraocular Lens Calcification After Pars Plana Vitrectomy
    (Mdpi, 2023) Bopp, Silvia; Ozdemir, Huseyin Baran; Aktas, Zeynep; Khoramnia, Ramin; Yildirim, Timur M.; Schickhardt, Sonja; Ozdek, Sengul
    Aim: To determine the clinical risk factors that may increase the occurrence of intraocular lens (IOL) calcification in patients who had undergone pars plana vitrectomy (PPV). Methods: The medical records of 14 patients who underwent IOL explantation due to clinically significant IOL opacification after PPV were reviewed. The date of primary cataract surgery, technique and implanted IOL characteristics; the time, cause and technique of PPV; tamponade used; additional surgeries; the time of IOL calcification and explantation; and IOL explantation technique were investigated. Results: PPV had been performed as a combined procedure with cataract surgery in eight eyes and solely in six pseudophakic eyes. The IOL material was hydrophilic in six eyes, hydrophilic with a hydrophobic surface in seven eyes and undetermined in one eye. The endotamponades used during primary PPV were C2F6 in eight eyes, C3F8 in one eye, air in two eyes and silicone oil in three eyes. Two of three eyes underwent subsequent silicone oil removal and gas tamponade exchange. Gas in the anterior chamber was detected in six eyes after PPV or silicone oil removal. The mean interval between PPV and IOL opacification was 20.5 +/- 18.6 months. The mean BCVA in logMAR was 0.43 +/- 0.42 after PPV, which significantly decreased to 0.67 +/- 0.68 before IOL explantation for IOL opacification (p = 0.007) and increased to 0.48 +/- 0.59 after the IOL exchange (p = 0.015). Conclusions: PPV with endotamponades in pseudophakic eyes, particularly gas, seems to increase the risk for secondary IOL calcification, especially in hydrophilic IOLs. IOL exchange seems to solve this problem when clinically significant vision loss occurs.
  • Article
    Citation - WoS: 172
    Citation - Scopus: 190
    Interpolative Reich-Rus Type Contractions on Partial Metric Spaces
    (Mdpi, 2018) Karapinar, Erdal; Agarwal, Ravi; Aydi, Hassen
    By giving a counter-example, we point out a gap in the paper by Karapinar (Adv. Theory Nonlinear Anal. Its Appl. 2018, 2, 85-87) where the given fixed point may be not unique and we present the corrected version. We also state the celebrated fixed point theorem of Reich-Rus-Ciric in the framework of complete partial metric spaces, by taking the interpolation theory into account. Some examples are provided where the main result in papers by Reich (Can. Math. Bull. 1971, 14, 121-124; Boll. Unione Mat. Ital. 1972, 4, 26-42 and Boll. Unione Mat. Ital. 1971, 4, 1-11.) is not applicable.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 14
    On Relations Between Transportation Cost Spaces and l1<
    (Academic Press inc Elsevier Science, 2020) Ostrovska, Sofiya; Ostrovskii, Mikhail I.
    The present paper deals with some structural properties of transportation cost spaces, also known as Arens-Eells spaces, Lipschitz-free spaces and Wasserstein spaces. The main results of this work are: (1) A necessary and sufficient condition on an infinite metric space M, under which the transportation cost space on M contains an isometric copy of l(1). The obtained condition is applied to answer the open questions asked by Cuth and Johanis (2017) concerning several specific metric spaces. (2) The description of the transportation cost space of a weighted finite graph G as the quotient l(1) (E(G))/Z(G), where E(G) is the edge set and Z(G) is the cycle space of G. (C) 2020 Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 3
    Existence of solutions of integral equations via fixed point theorems
    (Springeropen, 2014) Gulyaz, Selma; Erhan, Inci M.
    Existence and uniqueness of fixed points of a mapping defined on partially ordered G-metric spaces is discussed. The mapping satisfies contractive conditions based on certain classes of functions. The results are applied to the problems involving contractive conditions of integral type and to a particular type of initial value problems for the nonhomogeneous heat equation in one dimension. This work is a generalization of the results published recently in (Gordji et al. in Fixed Point Theory Appl. 2012:74, 2012, doi:10.1186/1687-1812-2012-74) to G-metric space.
  • Article
    Citation - WoS: 10
    Fixed Point Results in Orbitally Complete Partial Metric Spaces
    (Malaysian Mathematical Sciences Soc, 2013) Nashine, Hemant Kumar; Karapinar, Erdal
    In this paper, we prove two fixed point theorems for maps that satisfy a contraction principle involving a rational expression in complete partial metric spaces.
  • Article
    Citation - WoS: 35
    Citation - Scopus: 46
    Some unique fixed point theorems for rational contractions in partially ordered metric spaces
    (Springeropen, 2013) Arshad, Muhammad; Karapinar, Erdal; Ahmad, Jamshaid
    In this paper, we prove some unique fixed point results for an operator T satisfying certain rational contraction condition in a partially ordered metric space. Our results generalize the main result of Jaggi (Indian J. Pure Appl. Math. 8(2):223-230, 1977). We give several examples to show that our results are proper generalization of the existing one. MSC: 47H10, 54H25, 46J10, 46J15.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Pressure Injury Knowledge of Turkish Internship Nursing Students
    (Elsevier Sci Ltd, 2021) Sonmez, Munevver; Tasdemir, Nurten; Oren, Nursen
    Aim: This study aimed to describe the pressure injury (PI) knowledge of Turkish internship nursing students (INSs). Materials and methods: This descriptive study was performed using the Turkish version of the Modified Pieper Pressure Ulcer Knowledge Test. The study population consisted of INSs in a nursing program in the West Black Sea Region, Turkey. The sample of the study was 278 (74.1% of a total of 375 volunteer INSs). Results: The mean knowledge test score was 29.03 +/- 7.15 (range 11-44). The prevention/risk score was higher; only 28.4% of the students had a satisfactory test score. Conclusion: The results of this study indicated that the INSs had significant knowledge gaps regarding PI. Nursing students' knowledge deficiencies regarding PIs should be identified at undergraduate level, and the necessary educational measures should be taken.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Lyapunov-Type Inequalities for Lidstone Boundary Value Problems on Time Scales
    (Springer-verlag Italia Srl, 2020) Agarwal, Ravi P.; Oguz, Arzu Denk; Ozbekler, Abdullah
    In this paper, we establish new Hartman and Lyapunov-type inequalities for even-order dynamic equations x.2n (t) + (-1)n-1q(t) xs (t) = 0 on time scales T satisfying the Lidstone boundary conditions x.2i (t1) = x.2i (t2) = 0; t1, t2. [t0,8) T for i = 0, 1,..., n - 1. The inequalities obtained generalize and complement the existing results in the literature.