Some remarks on b-(E.A)-property in b-metric spaces

In this paper we consider, discuss, improve and generalize recent b-(E.A)-property results for mappings in b-metric spaces established by Ozturk and Turkoglu (J Nonlinear Convex Anal 16(10): 2059-2066, 2015). Thus, all our results are with much shorter proofs. One example is given to support the result

Common fixed point results for four mappings on partial metric spaces

We give fixed point results for four mappings which satisfy almost generalized contractive condition on partial metric space and we support the results with an example

On fixed points in the context of b-metric spaces

In this paper, we obtain sufficient conditions for the existence of common fixed points in the framework of ordered b-metric spaces. Our results generalize some recent results in the literature. Also, to illustrate the usability of the results we give an adequate example in which b-metric is not continuous

Trophic Characteristics of the Sapanca Lake (Turkey)

Systematic measurements of optical properties, concentrations of major and minor chemicals and primary production throughout 1989-1992 enabled us to identify the oligotrophic state of Sapanca lake, Marmara region, Turkey. Lake waters which have low concentrations of major anions and cations (total = 49 μM) overturn every February-March, ventilating the bottom waters and enriching the surface waters with nutrients. Surface waters cool down to 6.5 °C by late winter and then warm steadily to 26 °C by late summer, while temperatures in deep waters range between 6.5 and 10.0 °C throughout the year. When the seasonal thermocline develops, the dissolved oxygen profiles exhibit a subsurface maximum in the thermocline, while in the hypolimnion water, the content varies seasonally from 11.5-12.0 ppm (350-375 μM) in March to 0.5-1.7 ppm (16-56 μM) in late autumn. Surface nitrate concentrations vary markedly with season, from < 0.15 μM in summer to 5.7 μM in early March, whilst the bottom water concentrations range from 13.5-14.0 μM in late autumn to 5.7 μM after the winter overturn. Phosphate concentrations are always less than 0.1 μM throughout the entire water column. Subsurface chlorophyll-a maximum descends in late summer to 20-25 m depths, where the light intensity is less than 1% of the surface value. Below 10-15 m depths, corresponding to the upper thermocline, primary productivity is very low. The range was from 35 to 93 mg C/ m2 day-1 during 1989-1991, consistent with the values in other oligotrophic lakes

Microplastic pollution in Turkish aquatic ecosystems: Sources, characteristics, implications, and mitigation strategies

Aquatic environments are one of the final destinations for microplastics. In this review, a combination of systematic and narrative literature review was conducted to identify and summarise advances, gaps, and future directions in microplastic monitoring studies in the Turkish aquatic environment and in inhabiting aquatic organisms. A total of 62 peer-reviewed publications available on Web of Science were considered in the systematic review. Additionally, the current state of microplastic pollution in Turkish aquatic environments which includes marine and freshwater ecosystems, as well as aquatic organisms, and sources and characteristics of microplastics were reviewed narratively. Turkiye's position on the global plastic treaty and mitigation practices were also addressed. Although an increase in the number of publications over time was observed, the number and extent of studies carried out in freshwater ecosystems are limited. Strict legislation should be enacted and enforced to tackle plastic pollution in Turkiye. Additionally, nationwide, long-term monitoring studies at sufficiently regular intervals in aquatic environments should be considered

Fıxed poınt theorems ın cone metrıc and unıform spaces

Bu tez çalışmasında konik metrik uzaylarda ve düzgün uzaylarda bazı sabit nokta teoremleri incelenmiştir. Öncelikle ön bilgiler, bazı temel tanım ve teoremler verildi. Genel hatlarıyla konik metrik uzaylar tanıtıldı. Konik metrik uzaylarda çakışma noktası ve sabit nokta incelendi ve zayıf bağdaşık dönüşümler için çakışma noktasının sabit noktaya eşit olacağı görüldü. Ayrıca düzgün uzaylarda integral tipte iki büzülme koşulunu sağlayan dönüşümler için bazı sabit nokta teoremleri incelendi. Son olarak düzgün uzaylarda küme değerli zayıf büzülmenin random iterasyonu ve küme değerli dinamik sistemler ele alındı.In this thesis, some fixed point theorems in cone metric and uniform spaces have been studied. At first, background information, some basic definitions and theorems were given. Then cone metric spaces were given fundamentally. In cone metric spaces, coincidence point and fixed point have been studied and it was seen that coincidence point is same with fixed point for weakly compatible mappings. Also some fixed point theorems for selfmappings satisfying two contractive conditions of integral type in uniform spaces have been studied. Lastly set-valued dynamic systems and random iterations of set-valued weaker contractions in uniform space were given