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Numerical investigation of coalescing plate system to understand the separation of water and oil in water treatment plant of petroleum industry

Yayla, S. | Ibrahim, S.S. | Olcay, A.B.

Article | 2017 | Engineering Applications of Computational Fluid Mechanics11 ( 1 ) , pp.184 - 192

The most widely utilized process of produced water treatment is considered to be use of coalescing or corrugated plate systems in the oil industry because these systems have promising results in the acceleration of the separation process. Even use of corrugated plate systems seem to be effective in separation processes, the geometrical parameters of the plate system could greatly influence the performance of separation process. In this study, a two-dimensional computational fluid dynamics model for coalescing plates was developed to investigate Reynolds number and plate hole shape on separation efficiency. Spacing between plates was . . . set to 12 mm while fluid mixture’s Reynolds number varied between 5 and 45 for the computational model. Hole profile and dimensions were determined to be cylindrical, rectangular and ellipse shapes as 10, 15 and 20mmbased on hydraulic diameter definition, respectively. Furthermore, when hole profiles of coalescing plates were chosen to be ellipse and rectangular shapes, separation efficiency nearly stayed constant regardless of hole dimension. The study also reported that change of oil fraction from 5% to 15% caused approximately 30% increase in the separation efficiency. The investigation also revealed Reynolds number of the mixture was inversely proportional to the separation efficiency. It was also found that the highest separation efficiency was obtained for a cylindrical shape with a hole diameter of 15 mm when distance between plates was 12 mm and Reynolds number was 18. © 2017 The Author(s) Daha fazlası Daha az

Karyomorphology and nuclear DNA content of sixteen Ophrys L. taxa from Turkey

Deniz, İ.G. | Genç, İ. | Yücel, G. | Sümbül, H. | Sezik, E. | Tuna, M.

Article | 2018 | Plant Biosystems152 ( 4 ) , pp.711 - 719

Karyotypes in 16 representative taxa of the Ophrys genus are compared, based on Feulgen-stained somatic metaphase chromosomes. The karyotypes of O. omegaifera subsp. israelitica, O. ulupinara, O. lycia, O. argolica subsp. lucis, O. argolica subsp. lesbis, O. climacis and O. reinholdii subsp. reinholdii are described for the first time. Karyological analyses indicate relationships among the species with respect to their asymmetry indices. All Ophrys taxa studied were diploid with 2n = 2x = 36 chromosomes. One B chromosome has been detected among the chromosomes of O. argolica subsp. lucis. All karyotypes are symmetrical, consisting o . . .f metacentric and submetacentric chromosomes. The longest chromosomes of all the investigated specimens contain a secondary constriction. It is determined that there is a correlation between the total number of chromosomes having secondary constrictions and the evolutionary development order of the taxa. Based on nuclear DNA content, analysis was carried out by flow cytometer using propodium iodide as fluorochrome, 2C nuclear DNA content of 16 Ophrys species varying between 20.80 pg (O. argolica subsp. lucis) and 23.11 pg (O. omegaifera subsp. israelitica). Karyotype asymmetry relationships are discussed according to the bidimensional scatter plots of A1–A2, CVCL–CVCI, CVCL–MCA and CVCI–MCA. © 2017 Società Botanica Italiana Daha fazlası Daha az

Development and in vitro/in vivo evaluation of dihydroergotamine mesylate loaded maltodextrin-pullulan sublingual films

Esim, O. | Ozkan, C.K. | Kurbanoglu, S. | Arslan, A. | Tas, C. | Savaser, A. | Ozkan, Y.

Article | 2019 | Drug Development and Industrial Pharmacy45 ( 6 ) , pp.914 - 921

Dihydroergotamine mesylate (DHE), ergotamine derivative, has been offered for clinical use to stop or treat symptoms of an emerging migraine as injection for more than a half century. It is shown that bioavailability of DHE greatly changes between the subjects and up to 99% of the orally absorbed dose may be cleared by first pass metabolism. The aim of this study was to design and optimize DHE fast-dissolving sublingual films for migraine treatment. For this purpose pullulan and maltodextrin was chosen as film-forming polymers and propylene glycol as plasticizer. For optimization process Box Behnken design was used. The formed films . . . were free from air bubbles, cuttings, or cracks. Disintegration, mechanical strength and dissolution of films were compared. It is found that pullulan and maltodextrin formed films with the most desired properties at the concentration of 1.5% and 2%. The application of optimum formulation to rabbits showed that bioavailability of formulation is about 23.35% with a t max 20 min. Due to this fast onset of action and higher bioavailability than oral administration, it is suggested that the polymer combinations of pullulan and maltodextrin formed successful films and were considered as an alternative dosage form for DHE in migraine therapy. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Efficacy of multi-mode adhesive systems on dentin wettability and microtensile bond strength of resin composite

Arhun, N. | Halacoglu, D.M. | Ozduman, Z.C. | Tuncer, D.

Article | 2018 | Journal of Adhesion Science and Technology32 ( 21 ) , pp.2405 - 2418

Purpose: To evaluate the wetting ability and the microtensile bond strength of adhesive systems in various depths of dentin. Materials and Method: 48 extracted human molars cut in half in buccolingual direction. Buccal and lingual surfaces were used to obtain deep (n = 48) and superficial (n = 48) dentin. Groups were divided into 4 subgroups: Self-etch (CSE), etch&rinse (SB), multi-mode self-etch (SAU) and multimode etch&rinse (EAU) adhesive systems. 3 consecutive contact-angle measurements were obtained: T0- 3 µl drop of distilled water on dentin; T1-Droplet of the adhesive; T2- Distilled water after polymerization of the adhesive. . . . After composite build-ups, microtensile measurements were performed. Contact angle data were analysed with analysis of variance for repeated measures. Bond strength data were analyzed by repeated measures analysis of variance, comparisons were made according to the logarithmic values (p Daha fazlası Daha az

The effect of MDP-based primer on shear bond strength of various cements to two different ceramic materials

Pak Tunc, E. | Ozer, F. | Ayyildiz, S. | Ula, T.A. | Sen, D.

Article | 2017 | Journal of Adhesion Science and Technology31 ( 10 ) , pp.1142 - 1150

The aim of this study was to determine the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based primer on the shear bond strengths of thermally aged self-adhesive and conventional adhesive resin cements and zinc phosphate cement to zirconia and lithium disilicate substructures. Sixty zirconia (Z) and 60 lithium disilicate (L) disk specimens were cut from ceramic blocks. Each group was divided into six subgroups (n = 10). Half of the specimens of each ceramic group were treated with primer (P) and the other half was remained untreated. Three types of cement were applied: zinc phosphate cement [(ZPC) (Hoffmann Harmonic S . . .hades)]; self-adhesive resin cement [(SAC) (RelyX U200)]; conventional adhesive resin cement [(CAC) (C&B)]. The specimens were subjected to thermal aging procedure for 1 week under 37 °C water bath. Shear bond strength (SBS) was determined using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with three-way (ANOVA). Pairwise comparisons and interactions between groups were analyzed by using Tukey’s simultaneous confidence intervals. There was no significant difference between the SBS values of SAC-Z (11,47 ± 0,47) and SAC-ZP (11,39 ± 0,42) (p > 0.05). However, the SBS values of SAC-L (12.34 ± 0,55) and SAC-LP (12,50 ± 0,49) were significantly higher than those of SAC-Z and SAC-ZP (p Daha fazlası Daha az

Analysis of real world problems in mathematics textbooks of early twentieth and twenty-first century Turkish education: political and social reflections

Yilmaz, Z. | Ozyigit, S.E.

Article | 2017 | BSHM Bulletin32 ( 2 ) , pp.171 - 182

This paper aims to show that historical eras from the perspective of socio-political approaches can be linked to the context of mathematical real world problems in conformity with the eras they were used. Three mathematics high school textbooks were selected from the Hamidian era [1876–1909], Early Republican era [1923–28] and the Contemporary era [2002–]. A content analysis was carried out by taking the political events into consideration and linked them with the context of the problems. The problem contexts were examined under four general categories, military, gender, religion, and work force. Findings of the study indicated that . . . mathematics could be related to socio-political aspects of history. © 2016 British Society for the History of Mathematics Daha fazlası Daha az

Transit coordination with heterogeneous headways

Aksu, D.T. | Yilmaz, S.

Article | 2014 | Transportation Planning and Technology37 ( 5 ) , pp.450 - 465

We consider the transit coordination problem with heterogeneous headways. Timetables with heterogeneous headways improve coordination between transit lines and reduce transfer time for connecting passengers. Unfortunately, deviating from homogeneous headways impacts adversely on initial waiting times experienced prior to embarking on the initial vehicle of a trip. We focus on this trade-off between transfer waiting time and initial waiting time, which has not been explored previously, and develop a mathematical model to quantify the benefits of heterogeneous headways. We also propose a genetic algorithm (GA) to solve the transit coo . . .rdination problem with heterogeneous headways and demonstrate the benefit of heterogeneous headways based on two examples from the literature and one real-life example based on the rail transit network of Istanbul. Computational results suggest that the GA solves the transit coordination problem within a reasonable time and significant benefits can be achieved by adopting timetables with heterogeneous headways. © 2014 Taylor & Francis Daha fazlası Daha az

Tree crown detection and delineation in satellite images using probabilistic voting

Özcan, A.H. | Hisar, D. | Sayar, Y. | Ünsalan, Cem

Article | 2017 | Remote Sensing Letters8 ( 8 ) , pp.761 - 770

Crop yield forecasting in a region has become an important research area due to global warming and related climate changes. Although this can be performed by available statistical information, obtaining recent and up to date data to extract reliable statistical information is not easy. Very high resolution satellite images can be used for this purpose. However, manually processing these images acquired from large regions is neither feasible nor reliable. Therefore, automated methods are needed for this purpose. In this study, we propose a novel method to help forecasting the crop yield in an orchard. The number of trees in an orchar . . .d with the size and type of each tree crown gives an approximate crop that can be harvested. Therefore, we focus on both tree crown detection and delineation for this purpose. The proposed method for tree crown detection is based on probabilistic voting. For tree crown delineation, we propose a watershed segmentation based ellipse fitting method. We tested the proposed method on 17 satellite images containing 13,476 trees. We compared the method with the classical local maxima/minima filtering and a recent method in literature using three more test images. These tests indicate the strengths and weaknesses of the proposed method. © 2017 Informa UK Limited Daha fazlası Daha az

Transformation and integration through interpretation

Şahin, M.

Article | 2012 | Journal of Asian Architecture and Building Engineering11 ( 1 ) , pp.103 - 110

This article focuses on the re-examination and re-interpretation of a small but noteworthy pavilion designed and built in 1937. Compromising with the client's demands by creating a common ground and shared judgment, minimizing new resources and conserving energy by working with the local climate and conditions, the architect, in the late thirties, achieved an integrated design having both sentimental value and a raison d'être, that is to say, poetic and rational meanings of sustainability, which appear to be of significant value to contemporary design. The basic objective of this study is to rediscover, reinterpret and represent the . . . architect's peculiar solution to the problem of addition and transformation, along with his conception of preservation and remodeling issues; to underscore the complex web of spatiotemporal relations the design establishes with various regional and global contexts through observations, analysis and survey studies in the framework of the concept of integration. This particular design, an evident example of sustainable design and timelessness; concepts not yet then on the agenda of architecture, reveals that sustainability is not an added concept, but rather should be an intrinsic part of any architectural design Daha fazlası Daha az

Polyharmonic robin problem for complex linear partial differential equations

Aksoy, Ü. | Çelebi, A.O.

Article | 2014 | Complex Variables and Elliptic Equations59 ( 12 ) , pp.1679 - 1695

In this article, generalized polyharmonic Robin functions are introduced together with some of their properties. A hierarchy of integral operators with relevant kernel functions are investigated. These operators are used to transform the Robin problem for a 2nth order linear partial complex differential equation with polyharmonic leading term (generalized n-Poisson equation) into a singular integral equation having Fredholm property. © 2014 Taylor & Francis.

Schwarz problem for bi-analytic functions in multiply connected domains

Çelebi, A.O. | Mityushev, V.V.

Article | 2015 | Complex Variables and Elliptic Equations60 ( 4 ) , pp.566 - 582

The Schwarz problem for bi-analytic functions in unbounded circular multiply connected domains is considered. We combine constructive methods applied to boundary value problems for complex partial differential equations in simply connected domains and for the Riemann–Hilbert type problems in multiply connected domains. A general method is outlined and the case of doubly connected domains is discussed in details. Solution is obtained in the form of a series. © 2014, Taylor & Francis.

Modelling cadmium bioaccumulation in Gammarus pulex by using experimental design approach

Serdar, O. | Pala, A. | Ince, M. | Onal, A.

Article | 2019 | Chemistry and Ecology35 ( 10 ) , pp.922 - 936

Recently, although dynamic approaches have been used increasingly to describe metal bioaccumulation in aquatic organisms, the validation of such laboratory-derived modelling is rarely assessed under environmental conditions. The present study aims to evaluate and verify statistical and mathematical models for the bioaccumulation of cadmium (Cd) and to evaluate the suitability of Gammarus pulex as a biomonitor for Cd. To optimise Cd2+ ion bioaccumulation conditions a Box–Behnken design was used and whether G. pulex can be used as an estimated tool to assess aquatic quality was investigated. A Box–Behnken experimental design combined . . .with response surface modelling (RSM) was employed for Cd2+ bioaccumulation in G. pulex. Independent variables including temperature, contact time and Cd2+ ion concentration significance and their interactions were tested using analysis of variance. The selected variables’ optimum values were obtained by solving the quadratic regression model along with by analysing the response surface contour plots. Based on Box–Behnken design, the applied model is significant because model F-value and R2 were obtained as 5121.49, 0.9998, respectively. Bioaccumulation of Cd amount was analysed using electrothermal atomic absorption spectrophotometer. The obtained data suggest that G. pulex can be evaluated as Cd biomonitor. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

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