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Now showing 1 - 10 of 77
  • Article
    Citation - WoS: 38
    Citation - Scopus: 48
    Fixed Points of Modified f-contractive Mappings in Complete Metric-Like Spaces
    (Hindawi Ltd, 2015) Alsulami, Hamed H.; Karapinar, Erdal; Piri, Hossein
    We introduce the notion of modified F-contractive mappings in the setting of complete metric-like spaces and we investigate the existence and uniqueness of fixed point of such mappings. The presented results unify, extend, and improve several results in the related literature.
  • Article
    Citation - WoS: 43
    Coupled Fixed Points for Meir-Keeler Contractions in Ordered Partial Metric Spaces
    (Hindawi Ltd, 2012) Abdeljawad, Thabet; Aydi, Hassen; Karapinar, Erdal
    In this paper, we prove the existence and uniqueness of a new Meir-Keeler type coupled fixed point theorem for two mappings F : X x X -> X and g : X -> X on a partially ordered partial metric space. We present an application to illustrate our obtained results. Further, we remark that the metric case of our results proved recently in Gordji et al. (2012) have gaps. Therefore, our results revise and generalize some of those presented in Gordji et al. (2012)
  • Article
    Citation - WoS: 16
    Citation - Scopus: 17
    A Generalized Meir-Keeler Contraction on Partial Metric Spaces
    (Hindawi Ltd, 2012) Aydi, Hassen; Karapinar, Erdal; Rezapour, Shahram; Karapnar, Erdal
    We introduce a generalization of the Meir-Keeler-type contractions, referred to as generalized Meir-Keeler-type contractions, over partial metric spaces. Moreover, we show that every orbitally continuous generalized Meir-Keeler-type contraction has a fixed point on a 0-complete partial metric space.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 14
    Emergency Planning Zones Estimation for Karachi-2 and Karachi-3 Nuclear Power Plants using Gaussian Puff Model
    (Hindawi Ltd, 2016) Sahin, Sumer; Ali, Muhammad
    Emergency planning zones (PAZ and UPZ) around the Karachi-2 and Karachi-3 nuclear power plants (K-2/K-3 NPPs) have been realistically determined by employing Gaussian puff model and Gaussian plume model together for atmospheric transport, diffusion, and deposition of radioactive material using onsite and regional data related to meteorology, topography, and land-use along with latest IAEA Post-Fukushima Guidelines. The analysis work has been carried out using U.S. NRC computer code RASCAL 4.2. The assumed environmental radioactive releases provide the sound theoretical and practical bases for the estimation of emergency planning zones covering most expected scenario of severe accident and most recent multiunit Fukushima Accident. Sheltering could be used as protective action for longer period of about 04 days. The area about 3 km of K-2/K-3 NPPs site should be evacuated and an iodine thyroid blocking agent should be taken before release up to about 14 km to prevent severe deterministic effects. Stochastic effects may be avoided or minimized by evacuating the area within about 8 km of the K-2/K-3 NPPs site. Protective actions may become more effective and cost beneficial by using current methodology as Gaussian puff model realistically represents atmospheric transport, dispersion, and disposition processes in contrast to straight-line Gaussian plume model explicitly in study area. The estimated PAZ and UPZ were found 3 km and 8 km, respectively, around K-2/K-3 NPPs which are in well agreement with IAEA Post-Fukushima Study. Therefore, current study results could be used in the establishment of emergency planning zones around K-2/K-3 NPPs.
  • Article
    Citation - Scopus: 1
    Polarization Sensitive Reflection and Dielectric Spectra in Gase Thin Films
    (Hindawi Ltd, 2016) Khanfar, Hazem K.; Qasrawi, Atef A.
    The light polarization effects on the optical reflective and dielectric spectra of GaSe thin films are studied in the incident light wavelength range of 200-1100 nm. In this range of measurement, the angle of incidence (theta(i)) of light was varied between 30 degrees and 80 degrees. In addition, at theta(i) of 30 degrees the light polarizing angle (delta) was altered in the range of 0-90 degrees. Regardless of the value of lambda, for all theta(i) > 65 degrees, the total reflectance sharply decreased with increasing theta(i). In addition, when theta(i) is fixed at 30 and delta was varied, the amplitudes ratio of the polarized waves exhibits a resonance-antiresonance phenomenon at a wavelength that coincides with the film's thickness (800 nm). This behavior was assigned to the coupled interference between incident and reflected waves and to the strong absorption effects. Two main resonance peaks are observed as response to s-polarized and normal incident beam: one is at similar to 540 (556 nm) and the other at similar to 420 THz (714 nm). The dielectric constant of the GaSe films exhibits anisotropic characteristics that nominate it for use as multipurpose optoelectronic devices.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 21
    Some Results on Best Proximity Points of Cyclic Contractions in Probabilistic Metric Spaces
    (Hindawi Ltd, 2015) De la Sen, Manuel; Karapinar, Erdal; Karapńar, Erdal
    This paper investigates properties of convergence of distances of p-cyclic contractions on the union of the p subsets of an abstract set X defining probabilistic metric spaces and Menger probabilistic metric spaces as well as the characterization of Cauchy sequences which converge to the best proximity points. The existence and uniqueness of fixed points and best proximity points of p-cyclic contractions defined in induced complete Menger spaces are also discussed in the case when the associate complete metric space is a uniformly convex Banach space. On the other hand, the existence and the uniqueness of fixed points of the p-composite mappings restricted to each of the p subsets in the cyclic disposal are also investigated and some illustrative examples are given.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Concentration Dependent Different Action of Progesterone on the Order, Dynamics and Hydration States of the Head Group of Dipalmitoyl-Phosphatidylcholine Membrane
    (Hindawi Ltd, 2005) Korkmaz, F; Kirbiyik, H; Severcan, F
    Interactions of progesterone with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes (MLVs) were investigated as a function of progesterone concentration at selected temperatures monitoring both the gel and liquid crystalline phase, by using Fourier Transform Infrared spectroscopy (FTIR). It has been show that the effect of progesterone on membrane dynamics is dependent on progesterone concentration. At 1 mol%, which is close to physiological level, progesterone behaves differently. At this concentration the decrease in dynamics is more noticeable. Additionally a dramatic decrease in the strength of hydrogen bonding in the interfacial region of the bilayer is also observed. When concentration increases up to 12 mol% opposite behaviour is observed at all interactions. Above 12 mol%, progesterone-DPPC interactions shows almost linear plot.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 8
    Coupled Coincidence Point and Coupled Fixed Point Theorems via Generalized Meir-Keeler Type Contractions
    (Hindawi Ltd, 2012) Aydi, Hassen; Karapinar, Erdal; Erhan, Inci M.
    We prove coupled coincidence point and coupled fixed point results of F : X x X -> X and g : X -> X involving Meir-Keeler type contractions on the class of partially ordered metric spaces. Our results generalize some recent results in the literature. Also, we give some illustrative examples and application.
  • Article
    Citation - WoS: 41
    Citation - Scopus: 52
    Discussion on Generalized-(αψ, Βφ)-Contractive Mappings Via Generalized Altering Distance Function and Related Fixed Point Theorems
    (Hindawi Ltd, 2014) Berzig, Maher; Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio-Francisco
    We extend the notion of (alpha psi, beta phi)-contractive mapping, a very recent concept by Berzig and Karapinar. This allows us to consider contractive conditions that generalize a wide range of nonexpansive mappings in the setting of metric spaces provided with binary relations that are not necessarily neither partial orders nor preorders. Thus, using this kind of contractive mappings, we show some related fixed point theorems that improve some well known recent results and can be applied in a variety of contexts.
  • Article
    Citation - WoS: 4
    Best Proximity Points for Generalized α-ψ-Proximal Contractive Type Mappings
    (Hindawi Ltd, 2013) Jleli, Mohamed; Karapinar, Erdal; Samet, Bessem; Hamzehnejadi, Javad; Alqahtani, Badr; Lashkaripour, Rahmatollah
    We introduce a new class of non-self-contractive mappings. For such mappings, we study the existence and uniqueness of best proximity points. Several applications and interesting consequences of our obtained results are derived.