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Non-linear response of the rockfill in a concrete-faced rockfill dam under seismic excitation

Kartal M.E. | Bayraktar A.

Article | 2015 | Mathematical and Computer Modelling of Dynamical Systems21 ( 1 ) , pp.77 - 101

This study investigates the non-linear response of the rockfill in a concrete-faced rockfill dam under seismic excitation for various concrete slab thicknesses from 30 to 100 cm thick. The effect of the friction in the concrete slab rockfill interface on the non-linear response of the rockfill is also considered in the numerical solutions. The friction contact in the concrete slab joints is provided with contact elements based on the Coulomb’s friction law. The hydrodynamic pressure of the reservoir water is considered by the fluid finite elements based on the Lagrangian approach. Geometrical and material non-linear behaviours of th . . .e dam-foundation-reservoir interaction system are considered together in the finite element analyses. The Drucker–Prager model is used to obtain materially non-linear behaviour of the concrete slab. The multi linear kinematic hardening model is used for rockfill and foundation rock in the material non-linear analyses. Therefore, the uniaxial stress–strain relations of the rockfill and foundation rock are determined from the shear stress–shear strain relations of the gravel and rock, respectively. The principle compressive and tensile stresses of the rockfill are investigated along the horizontal section of the rockfill. According to numerical analyses, the most critical stresses occur in the upstream and downstream faces of the dam for the concrete slab thickness of 30 cm, while the optimum thickness for seismic performance is 58 cm. © 2014, © 2014 Taylor & Francis Daha fazlası Daha az

Equilibrium, Kinetics, and Thermodynamics of Bovine Serum Albumin Adsorption on Single-Walled Carbon Nanotubes

Kopac T. | Bozgeyik K.

Article | 2016 | Chemical Engineering Communications203 ( 9 ) , pp.1198 - 1206

We investigated the equilibrium, kinetics, and thermodynamics of bovine serum albumin (BSA) adsorption on single-walled carbon nanotubes (SWNTs) from aqueous solutions with different pH and temperatures. We analyzed the experimental adsorption equilibrium and kinetic data to evaluate the adsorption characteristics of SWNTs for BSA. The results show that the effects of pH and temperature were important. Moreover, the adsorption isotherm data of BSA on SWNTs are consistent with the Langmuir and Freundlich models, while the kinetics can be expressed by the pseudo-first-order and the intraparticle diffusion rate models. The maximum prot . . .ein adsorption capacity of SWNTs, which have a surface area of 191.2 m2/g, was found to be 609.8 mg g-1 at pH 4 and 40°C, and this was the highest value obtained among our previous studies examined with various metal oxides. In addition, the zeta potential measurements were examined to understand the effects of charge density of the surface and the protein on the adsorption process. Thermodynamic analysis results indicate that the nature of adsorption changes with pH. SWNTs were found to be effective for BSA adsorption. © 2016, Copyright © Taylor & Francis Group, LLC Daha fazlası Daha az

Area-based quality control of airborne laser scanning 3D models for different land classes using terrestrial laser scanning: sample survey in Houston, USA

Sefercik U.G. | Glennie C. | Singhania A. | Hauser D.

Article | 2015 | International Journal of Remote Sensing36 ( 23 ) , pp.5916 - 5934

Airborne laser scanning (ALS) is a remote-sensing technique that provides scale-accurate 3D models consisting of dense point clouds with x, y planimetric coordinates and altitude z. Using ALS, very high-resolution (VHR) digital surface models (DSMs) have been widely used for commercial and scientific applications since the early 1990s. Although there is widespread usage, there has been little comprehensive investigation of quality control for ALS DSMs in the literature, as most studies have been limited to assessing point-based vertical accuracy. This article is dedicated to investigating the quality of ALS DSMs for different land c . . .lasses using statistical and visual approaches based on absolute and relative vertical accuracy metrics. Rather than a limited number of ground control points (GCP), the model-to-model-based approach is applied and DSMs derived from terrestrial laser scanning (TLS) point clouds that have around 5 mm absolute and 3 mm relative geolocation accuracy were used as the reference data for comparison. The results demonstrate that in open, grass, and building land classes, the ALS DSMs reached both standard deviation (?) and normalized median absolute deviation (NMAD) of 3–5 cm after the elimination of any systematic biases. This result sufficiently satisfies the vertical accuracy requirements for 1/1000-scale topographic maps determined by National Digital Elevation Program (NDEP) specifications. In tall vegetation, a higher number of discrepancies larger than 0.5 m exist, reversing the relation between ? and NMAD. These vegetation errors also do not appear to be normally distributed. As an additional investigation, the performance of ALS DEMs under dense high-vegetation areas was assessed. These under-canopy ALS DEMs, created using only classified ground returns, offer both ? and NMAD of 12–14 cm, a performance level that is difficult to achieve under-canopy using photogrammetric techniques. © 2015 Taylor & Francis Daha fazlası Daha az

Antibacterial chitosan/silk sericin 3D porous scaffolds as a wound dressing material

Karahaliloglu Z. | Kilicay E. | Denkbas E.B.

Article | 2017 | Artificial Cells, Nanomedicine and Biotechnology45 ( 6 ) , pp.1172 - 1185

Antimicrobial mixed dressings have traditionally been used to minimize bacterial infection of burns and other wounds. This study presents the advancement of biocompatible chitosan/silk sericin (CHT/SS) scaffolds combined with lauric acid (LA) and zinc oxide nanoparticles (nZnO) for the successful wound dressing applications. Antibacterial assay results showed that the diameters of the inhibition zone increased from 2 ± 0.4 to 7 ± 0.1 mm for Escherichia coli, as well as from 2.5 ± 0.2 to 6 ± 0.4 mm for Staphylococcus aureus while CHTS/SS/100nZnO compared to CHT/SS/0.01LA. The results not only showed excellent inhibition against Gram- . . .positive and Gram-negative bacterial growth but also revealed improved proliferation and extended viability for HaCaT cells. © 2016 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

A subclass supported convolutional neural network for object detection and localization in remote-sensing images

Kilic E. | Ozturk S.

Article | 2019 | International Journal of Remote Sensing40 ( 11 ) , pp.4193 - 4212

This article proposes a novel subclass-based classifier based on convolutional neural networks (CNNs) for detecting objects more accurately on remote-sensing images. The proposed classifier, called subclass supported CNN (SSCNN), is used to separate the representation of the objects into subclasses such as nearcentre, centre, and border depending on the distance of the object centre to obtain more effective feature extractor. A three-stage object recognition framework is used to evaluate the performance of the proposed classifier. In the first of these stages, the Selective Search algorithm generates object proposals from the image. . . . Then, the proposed SSCNN classifies the proposals. Finally, subclass-based localization evaluation function has been proposed to calculate the localization of the object with classification results. Due to the limited number of satellite image samples, pretrained AlexNet is used by transfer learning approach to build effective feature extractor. The proposed method has been compared with region-based CNN (R-CNN) on a four-class remote-sensing test dataset consisting of 411 airplanes, 240 baseball diamonds, 468 storage tanks, and 83 ground track fields. In addition, Faster R-CNN has been trained with SSCNN features and the performances of the trained Faster R-CNNs are comparatively evaluated on 10-class remote-sensing image dataset. Experiment results have shown that the proposed framework can locate the objects precisely. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Chemometric approach to the optimisation of LC-FL and GC-MS methods for the determination of nitrite and nitrate in some biological, food and environmental samples

Ata Ş. | Akyüz M. | Dinç E.

Article | 2016 | International Journal of Environmental Analytical Chemistry96 ( 7 ) , pp.636 - 652

Gas chromatography–mass spectrometry (GC-MS) method and a liquid chromatography–fluorescence (LC-FL) detection method using experimental design and optimisation approach were improved for the quantitative determination of nitrite and nitrate in biological, food and environmental samples. The obtained recoveries of nitrite and nitrate ions from samples based on both GC-MS and LC-FL results ranged from 98.5% to 98.9% for nitrite and 97.9% to 98.4% for nitrate. The precision of these methods, as indicated by the relative standard deviations (RSDs), was within the range from 2.4% to 3.6% for nitrite and 2.5% to 3.8% for nitrate, respect . . .ively. The limits of detection of nitrite and nitrate ions from samples based on GC-MS and LC-FL results ranged from 0.01 to 0.14 ng L-1 for nitrite and 0.02 to 0.71 ng L-1 for nitrate, respectively. The optimised isolation procedure by central composite design was successfully applied to real samples. The results revealed that the proposed procedure combined with GC-MS and LC-FL techniques is more sensitive, reliable and selective compared to the other methods available for the precise determination of trace levels of nitrite and nitrate in biological, food and environmental samples. © 2016 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Comparative evaluation of push-out bond strength of Neo MTA Plus with Biodentine and white ProRoot MTA

Aktemur Türker S. | Uzunoğlu E. | Bilgin B.

Article | 2017 | Journal of Adhesion Science and Technology31 ( 5 ) , pp.502 - 508

Objective: The aim of this in vitro study was to evaluate the bond strength of a new calcium silicate cement, Neo MTA Plus (Avalon Biomed Inc. Bradenton, FL, U.S.A) by comparing ProRoot MTA and Biodentine. Material and Methods: Sixty dentin slices were instrumented to achieve a diameter of 1.3 mm. Group 1: white ProRoot MTA, group 2: Biodentine, group 3: Neo MTA Plus–G (powder mixed with gel), group 4: Neo MTA Plus–W (powder mixed with distilled water) were loaded into cavities. The push-out bond strength values were measured. Data were analyzed using Welch ANOVA with Bonferroni correction p = 0.05. Failure modes (adhesive, cohesive . . ., and mixture) were analyzed. Results: The highest bond strength value was recorded in Neo MTA Plus mixed with gel (5.23 ± 1.78 MPa), whereas white ProRoot MTA (2.57 ± 0.66 MPa) had the lowest. Bond strength values of Neo MTA Plus mixed either with gel or with distilled water were statistically different from both white ProRoot MTA and Biodentine (2.61 ± 0.70 MPa) (p Daha fazlası Daha az

Geometric correction accuracy of different satellite sensor images: Application of figure condition

Sertel E. | Kutoglu S.H. | Kaya S.

Article | 2007 | International Journal of Remote Sensing28 ( 20 ) , pp.4685 - 4692

In this study, the figure condition method was introduced to analyse the accuracy of geometric correction. Figure condition denotes the transformation ability of estimated model parameters for a given transformation model, and it can be used in a geometric correction procedure. To study the figure condition, multisensor satellite images were geometrically corrected using ground control points obtained by different methods. The accuracy of each geometric model was analysed by means of the root mean square error of unit weight and variance-covariance matrix of unknown parameters. Then, an error propagation law was applied to the geome . . .tric model in order to investigate the transformation ability of the model parameters and estimate error values of geometric correction for the whole image surface. The results of the research demonstrated that the figure condition can be applied to geometric correction, and error values of the whole study area can be obtained with this new approach without using check points Daha fazlası Daha az

Information content of optical satellite images for topographic mapping

Topan H. | Maktav D. | Jacobsen K. | Buyuksalih G.

Conference Object | 2009 | International Journal of Remote Sensing30 ( 7 ) , pp.1819 - 1827

Geometric high-resolution satellite imagery (HRSI) is being used increasingly for generating large-scale topographic maps. The detection of object shapes has become easier and more accurate with improved geometric resolution. The grey value range and spectral resolution are also important for the identification and classification of objects. The nominal ground sampling distance (GSD) must not be the same as the effective GSD corresponding to the information content. In addition, the topographic conditions, object contrast, sun elevation and azimuth and atmospheric conditions influence the object identification. The information conte . . .nt of panchromatic and multispectral satellite images (Landsat 7 ETM+, ASTER, TK-350, KVR-1000, SPOT-5, IRS-1C, IKONOS, QuickBird and OrbView-3) available for the Zonguldak test field were investigated with respect to the generation of large-scale topographic maps. The rule of thumb for topographic mapping of at least 0.1 mm GSD in the map scale with the limit of a maximum of 5 m GSD also for smaller map scales has been confirmed Daha fazlası Daha az

Quantifying coherence between TDM90, SRTM90 and ASTER90

Sefercik U.G.

Article | 2019 | Geocarto International , pp.1819 - 1827

German Aerospace Centre released TanDEM-X 90 m (TDM90) global digital elevation model (GDEM) as freely available in October, 2018 and declared that it describes all Earth’s landmasses pole to pole with 1 m absolute height accuracy which could not been achieved by previous space-borne GDEMs. In this study, the coherence level of TDM90 with SRTM90 and ASTER90 were comprehensively analysed by visual and statistical comparison approaches in two study areas including different topographic characteristics. In visual approaches, colour-scaled coherence maps, contour maps, aspects depending on ascending and descending flying orbits and outl . . .ier illustrations were generated and interpreted. In statistical approaches, horizontal and vertical absolute and relative geolocation disparities and frequency distributions of height differences were presented. The results demonstrated that the terrain slope has a great impact on the coherence levels between TDM90 and compared GDEMs. Overall, TDM90 is more coherent with SRTM90 against ASTER90 except clear dissimilarity problems in strip border lines. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

Spectroscopic and structural properties of complexes of 3,3'-bis(2-benzimidazolyl)-2,2'-bipyridine with copper(i) and silver(i)

Şengül A. | Kurt Ö. | Adler P.D.F. | Coles S.J.

Article | 2014 | Journal of Coordination Chemistry67 ( 14 ) , pp.2365 - 2376

The pseudo-tetrahedral complexes [CuL2]PF6·7H2O·CH3OH (1) and [AgL2]CF3SO3·H2O (2) (L = 3,3’-bis(2-benzimidazolyl)-2,2’-bipyridine) have been synthesized and characterized through crystal structure analyses, electrochemistry, and spectroscopic methods. X-ray structural analyses of 1 and 2 indicate that sterically constrained N4 ligands L are cis and behave as bidentate chelates to a single metal ion in a pseudo-tetrahedral fashion through the benzimidazole. As two benzimidazolyl rings exhibit considerable steric hindrance, the bipyridine unit of L remains uncoordinated. The pseudo-tetrahedral cation [CuL2]+ shows a quasi-reversible . . .CuI/CuII oxidation–reduction wave in the CV in DMF (counter-ion PF6-). The fluorescence titration of L with copper(I), silver(I), and also with pH have been conducted to examine the selectivity. The ligand shows remarkably high selectivity and sensitivity for Ag(I). © 2014 Taylor & Francis Daha fazlası Daha az

Quality function deployment in the speculative house-building market: How to satisfy high-income customers

Ulubeyli S. | Kazaz A. | Soycopur B. | Er B.

Article | 2015 | International Journal of Construction Management15 ( 2 ) , pp.148 - 156

This paper presents a study that reports a detailed process of 'quality function deployment', considering an ultra-luxury villa project. It is based on a questionnaire survey that was applied to 42 residents and seven top managers. The results highlight real expectations of high-income residents. Residents were not satisfied with the 'sauna', 'sports areas', and 'fitness centre' despite the fact that these were among the least important expectations. However, residents were satisfied with the 'security of the complex', 'architectural design', and 'quality of the end-products'. If some expectations (i.e. 'areas for common use', 'play . . .ing areas for children', and 'quality of the end-products') achieve better technical standards in the next projects, demand for luxury residences will likely be improved. Consequently, 25 expectations and corresponding findings constitute a preliminary framework for an expectations agenda for such projects for builders who wish to improve marketing practices. © 2015 Taylor & Francis Daha fazlası Daha az

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