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Now showing 1 - 10 of 672
  • Article
    Citation - WoS: 7
    Citation - Scopus: 10
    Ann-Assisted Forecasting of Adsorption Efficiency To Remove Heavy Metals
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Buaısha, Magdi; Balku, Şaziye; Yaman, Şeniz Özalp
    In wastewater treatment, scientific and practical models utilizing numerical computational techniques suchas artificial neural networks (ANNs) can significantly help to improve the process as a whole through adsorption systems.In the modeling of the adsorption efficiency for heavy metals from wastewater, some kinetic models have been used such as pseudo first-order and second-order. The present work develops an ANN model to forecast the adsorption efficiency of heavy metals such as zinc, nickel, and copper by extracting experimental data from three case studies. To do this, we apply trial-and-error to find the most ideal ANN settings, the efficiency of which is determined by mean square error (MSE) and coefficient of determination (R2). According to the results, the model can forecast adsorption efficiency percent (AE%) with a tangent sigmoid transfer function (tansig) in the hidden layer with 10 neurons and a linear transferfunction (purelin) in the output layer. Furthermore, the Levenberg–Marquardt algorithm is seen to be most ideal for training the algorithm for the case studies, with the lowest MSE and high R2 . In addition, the experimental results and the results predicted by the model with the ANN were found to be highly compatible with each other.
  • Article
    ON A GENERALIZED α-ADMISSIBLE RATIONAL TYPE CONTRACTIVE MAPPING
    (Yokohama Publ, 2016) Erhan, Inci M.; Kir, Mehmet
    Recently, many generalized contractive conditions which involve rational contractive inequalities have been introduced in the context of partially ordered metric spaces. In this paper, we aim to give a generalized rational contractive condition which involves some of these results without need of extra restrictions.
  • Conference Object
    Citation - Scopus: 1
    Crm System Implementation in a Multinational Enterprise
    (2009) Mishra,A.; Mishra,D.
    The concept of customer relationship management (CRM) resonates with managers in today's competitive economy. As more and more organizations realize the significance of becoming customer-centric in today's competitive era, they embrace CRM as a core business strategy. CRM an integration of information technology and relationship marketing provides the infrastructure that facilitates long-term relationship building with customers at an enterprise-wide level. Successful CRM implementation is a complex, expensive and rarely technical projects. This paper presents the successful implementation of CRM in a multinational organization. This study will facilitate in understanding transition, constraints and implementation of CRM in multinational enterprises. © Springer-Verlag 2009.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Construction of Self-Assembled Vertical Nanoflakes on Cztsse Thin Films
    (Iop Publishing Ltd, 2019) Terlemezoglu, M.; Surucu, O. Bayrakli; Colakoglu, T.; Abak, M. K.; Gullu, H. H.; Ercelebi, C.; Parlak, M.
    Cu2ZnSn(S, Se)(4) (CZTSSe) is a promising alternative absorber material to achieve high power conversion efficiencies, besides its property of involving low-cost and earth-abundant elements when compared to Cu(In, Ga) Se-2 (CIGS) and cadmium telluride (CdTe), to be used in solar cell technology. In this study, a novel fabrication technique was developed by utilizing RF sputtering deposition of CZTSSe thin films having a surface decorated with self-assembled nanoflakes. The formation of nanoflakes was investigated by detailed spectroscopic method of analysis in the effect of each stacked layer deposition in an optimized sequence and the size of nanoflakes by an accurate control of sputtering process including film thickness. Moreover, the effects of substrate temperature on the formation of nanoflakes on the film surface were discussed at a fixed deposition route. One of the main advantages arising from the film surface with self-assembled nanoflakes is the efficient light trapping which decreases the surface reflectance. As a result of the detailed production and characterization studies, it was observed that there was a possibility of repeatable and controllable fabrication sequence for the preparation of CZTSSe thin films with self-textured surfaces yielding low surface reflectance.
  • Article
    Citation - WoS: 32
    Citation - Scopus: 45
    Fixed Point Theorems for a Class of Α-Admissible Contractions and Applications To Boundary Value Problem
    (Hindawi Publishing Corporation, 2014) Alsulami, Hamed H.; Gulyaz, Selma; Karapinar, Erdal; Erhan, Inci M.
    A class of alpha-admissible contractions defined via altering distance functions is introduced. The existence and uniqueness conditions for fixed points of such maps on complete metric spaces are investigated and related fixed point theorems are presented. The results are reconsidered in the context of partially ordered metric spaces and applied to boundary value problems for differential equations with periodic boundary conditions.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 10
    Synthesis and Characterization of Hydrothermally Grown Potassium Titanate Nanowires
    (Korean Assoc Crystal Growth, inc, 2015) Kapusuz, Derya; Kalay, Y. Eren; Park, Jongee; Ozturk, Abdullah; Metallurgical and Materials Engineering
    Potassium titanate (KT) nanowires were synthesized by a one-step hydrothermal reaction between TiO2 and aqueous KOH solution. The effects of KOH concentration and reaction time on hydrothermal formation and KT nanowire growth were investigated. The nanowire growth mechanism was elucidated using a combined study of powder X-ray diffraction, and scanning and transmission electron microscopy. The results revealed that hydrothermal growth was initiated by the formation of amorphous-like Ti-O-K sheets in anatase. Increasing hydrothermal reaction time caused the transformation of anatase to Ti-O-K sheets, from which potassium hexa-titanate (K2Ti6O13) nuclei formed and grew to establish one-dimensional morphology through preferential growth along the b-axis. It was revealed that the hydrothermal reactions followed a quite different mechanism than the well-known calcination route. Potassium tetra-titanate (K2Ti4O9) crystals formed in the amorphous region using the hexa-titanate phase as a nucleation site for heterogeneous crystallization. Increasing the KOH concentration in the solution accelerated the hydrothermal reaction rate.
  • Conference Object
    Citation - Scopus: 12
    Design and Implementation of a Mobile Webcast Application With Google Analytics and Cloud Messaging Functionality
    (Institute of Physics Publishing, 2019) Jonathan,O.; Misra,S.; Ibanga,E.; Maskeliunas,R.; Damasevicius,R.; Ahuja,R.
    Church cast is an application developed to bring the messages of ministries closer to their members by harnessing the Internet and mobile devices. Due to the very busy schedules of people and religious restrictions in some countries, people are not usually able to be physically present at their locations of worship to listen to or watch their ministers. Existing applications developed in the past like DOMI radio and Redemption TV Media were limited to only audio, poor and unintuitive user interfaces and not providing the administrator any interactions with the users of the application. In this work, we develop an Android-based application that makes it possible for users to watch live streams and on-demand videos from their ministries using their mobile devices. The application also incorporates sharing and analytics functionalities to enable users to share videos messages with loved ones and help the administrator monitor users' activities on the application respectively. The cloud messaging functionality enables the administrator to send messages such as announcements to user devices as push notifications. This would eventually increase user knowledge and interaction with the activities going on in their respective places of worship. © 2019 Published under licence by IOP Publishing Ltd.
  • Article
    Common Fixed Point Theorem for Three Mappings in Banach Valued Norm Spaces
    (Gazi Univ, 2013) Karapinar, Erdal; Moradlou, Fridoun; Salimi, Peyman; Mathematics
    In this paper, we give a generalized theorem on point of coincidence and common fixed point for three weakly compatible mappings in Banach valued norm spaces. We give a new method for construction of the sequence, which is convergence to the common fixed point of these three mappings.
  • Article
    Citation - WoS: 9
    Fixed Point Results for Almost Generalized Cyclic (ψ, Φ)-Weak Contractive Type Mappings With Applications
    (Hindawi Publishing Corporation, 2012) Jleli, Mohamed; Karapinar, Erdal; Samet, Bessem
    We define a class of almost generalized cyclic (psi,phi)-weak contractive mappings and discuss the existence and uniqueness of fixed points for such mappings. We present some examples to illustrate our results. Moreover, we state some applications of our main results in nonlinear integral equations.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 17
    Calcination Characteristics of Laterite Ores From the Central Region of Anatolia
    (Southern African inst Mining Metallurgy, 2012) Keskinkilic, E.; Pournaderi, S.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials Engineering
    Drying, calcination, prereduction, and smelting are the main steps in conventional crude ferronickel production. Industrially, these steps are conducted using the rotary kiln-electric arc furnace (RKEF) process. In this paper, calcination characteristics of Sivrihisar laterite ores from the Central Anatolia region are investigated. The extent of elimination of chemically bound water and other volatiles was studied by experiments conducted at various temperatures in the 250-800 degrees C range. Phase changes were examined using X-ray diffractometry. For the particle size used in the study, 300 degrees C was determined to be almost sufficient for complete transformation of goethite to haematite, and 700 degrees C was required for effective elimination of all volatiles in the ore.