Yazarlar
- Bayram, Ozkan(7)
- Simsek, Onder(5)
- Dertli, Enes(4)
- Guney, Harun(3)
- Igman, Erdal(3)
- Akın, Nihat(2)
- Artar, Musa(2)
- Bayram, Nesrin Ecem(2)
- Demirtas, M.(2)
- Erdogan, Ummugulsum(2)
- Ertargin, Mehmet Emrah(2)
- Mercan, Emin(2)
- Purcek, G.(2)
- Sert, Durmuş(2)
- Sorkun, Kadriye(2)
- Yanar, H.(2)
- Abdioglu, M.(1)
- Abuşoğlu, Ayşegül(1)
- Agar, Guleray(1)
- Akdeniz, Dilsad Güven(1)
- Akkus, B.(1)
- Akyol, Hayati(1)
- Aloui, F(1)
- Andiç-Çakır, Özge(1)
- Argün, Ziya(1)
- Aruntas, Huseyin Y.(1)
- Ates, Fadime(1)
- Ates, Sevket(1)
- Aygün, Bünyamin(1)
- Ayten, Kagan Koray(1)
- Ayşegül, Çokgez Kuş(1)
- Bahadır, Zekeriyya(1)
- Bayram, Özkan(1)
- Bektaş, Hakan(1)
- Belaidi, Salah(1)
- Besir, Ahmet B.(1)
- Beydemir, Şükrü(1)
- Birgul, Recep(1)
- Bochvar, N.R.(1)
- Bolat, Fevzi Cakmak(1)
Yayınlar
- MakaleYayıncıda açık erişim2018Isolation and characterisation of lactic acid bacteria from traditional koumiss and kurut
Ispirli, Hümeyra; Dertli, Enes
Lactic acid bacteria (LAB) were isolated from traditional koumiss and kurut samples and identification of these isolates revealed the presence of Lactobacillus fermentum, Enterococcus faecalis, Enterococcus durans, and Lactobacillus helveticus species. L. fermentum and L. helveticus strains were further tested for different characteristics. All tested strains produced heteropolymeric exopolysaccharides (EPS) with the presence of glucose and galactose as sugar monomers whereas three strains produced fructan type EPS as homopolymeric EPS. Important levels of antibacterial and antifungal activities were observed in these strains. All tested strains were sensitive to the antibiotics tested except streptomycin. Half of the tested strains showed important levels of survival ability under mimicking gastrointestinal conditions.
AtıfScopus20
İncele - MakaleYalnız künye2018Investigation of the effect of RF energy on optical, morphological, chemical and antibacterial properties of PolyTerpenol thin films obtained by RF-PECVD technique
Bayram, Ozkan; Simsek, Onder
In this study, it was aimed to obtain PolyTerpenol thin films by radio frequency plasma enhanced chemical vapor deposition technique using Terpinen-4-ol essential oil, which is organic compounds. The surface morphology and chemical properties of polymer thin films were investigated by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy. AFM analyzes of PolyTerpenol thin films revealed that the thin films are homogeneous, smooth and nonporous. The optical properties of the thin films were determined using UV–Vis spectrophotometer. When optical band gaps of thin films were examined, it was found that this value varied from 3.83 to 3.20 eV. The extinction coefficients of the obtained thin films according to the increasing RF energy were calculated as 0.0011, 0.0060, 0.0085 and 0.0150, respectively, at a wavelength of 320 nm. In addition, antibacterial effects of these thin films against Escherichia Coli (E.Coli) bacteria were also investigated. The PolyTerpenol thin films were found to have high antibacterial activity against E. Coli bacteria.
AtıfScopus8İncele - MakaleYayıncıda açık erişim2018Synthesis of Enantiomerically Enriched Drug Precursors by Lactobacillus paracasei BD87E6 as a Biocatalyst
Öksüz, Selda; Şahin, Engin; Dertli, Enes
Global sales of single enantiomeric drug products are growing at an alarming rate every year. A total of 7 bacterial strains were screened for their ability to reduce acetophenones to its corresponding alcohol. Among these strains Lactobacillus paracasei BD87E6 was found to be the most successful biocatalyst to reduce the ketones to the corresponding alcohols. The reaction conditions were systematically optimized for the reducing agent Lactobacillus paracasei BD87E6, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale asymmetric reduction of 3-methoxyacetophenone (1h) by Lactobacillus paracasei BD87E6 gave (R)-1-(3-methoxyphenyl)ethanol (2h) with 92% yield and 99% enantiomeric excess. Compound 2h could be used for the synthesis of (S)-rivastigmine which has a great potential for the treatment of Alzheimer's disease. This study demonstrates that Lactobacillus paracasei BD87E6 can be used as a biocatalyst to obtain chiral carbinol with excellent yield and selectivity. The whole cell catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that Lactobacillus paracasei BD87E6 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest.
AtıfScopus16
İncele - MakaleYalnız künye2018X-ray CT monitoring of macro void development in mortars exposed to sulfate attack
Tekin, Ilker; Birgul, Recep; Aruntas, Huseyin Y.
This study reports the results of nondestructive monitoring of macro void developments in mortars manufactured with both ordinary Portland cement and sulfate resistant cement. Two types of curing were utilized; tap water curing and another curing environment that contains 5% Na2(SO4) solution. Being the primary objective of this study, macro void developments of the mortar specimens were monitored by X-ray Medical Computerized Tomography. Compressive strength tests and water absorption tests were conducted on specimens that were kept in both curing environments for a duration of 560 days. Data analyses yielded consistent results among the three tests used in this experimental study. Macro void ratios of mortars decreased at the beginning of experiments for a certain period; afterwards, macro void ratios increased. The objective of this study was accomplished as anticipated since X-CT image analysis was able to nondestructively monitor macro void development process in cement mortars.
AtıfScopus6WoS6
İncele - MakaleYalnız künye2018Stochastic responses of isolated bridge with triple concave friction pendulum bearing under spatially varying ground motion
Yurdakul, Muhammet; Ates, Sevket
This study aims to investigate the stochastic response of isolated and non-isolated highway bridges subjected to spatially varying earthquake ground motion model. This model includes wave passage, incoherence and site response effects. The wave passage effect is examined by using various wave velocities. The incoherency effect is investigated by considering the Harichandran and Vanmarcke coherency model. The site response effect is considered by selecting homogeneous firm, medium and soft soil types where the bridge supports are constructed. The ground motion is described by power spectral density function and applied to each support point. Triple concave friction pendulum (TCFP) bearing which is more effective than other seismic isolation systems is used for seismic isolation. To implement seismic isolation procedure, TCFP bearing devices are placed at each of the support points of the deck. In the analysis, the bridge selected is a five-span featuring cast-in-place concrete box girder superstructure supported on reinforced concrete columns. Foundation supported highway bridge is regarded as three regions and compared its different situation in the stochastic analysis. The stochastic analyses results show that spatially varying ground motion has important effects on the stochastic response of the isolated and non-isolated bridges as long span structures.
AtıfScopus13WoS13İncele - MakaleYalnız künye2018Determining the Patient-Specific Optimum Osteotomy Line for Severe Mandibular Retrognathia Patients
Şensoy, Abdullah Tahir; Kaymaz, Irfan; Ertaş, Ümit; Kiki, Ali
Purpose: The purpose of this study is to suggest a patient-specific osteotomy line to optimize the distractor position and thus to minimize the disadvantages of conventional mandibular distraction osteogenesis (MDO) protocols. In addition, this study also aims to compare the conventional MDO protocols with the new MDO protocol proposed in this study in terms of both orthodontic outcomes and mechanical effects of osteotomy level on callus stabilization by means of the finite element method. Methods: A preoperative patient-specific 3-dimensional bone model was created and segmented by using computed tomography images of an individual patient. Virtual orthodontic set-up was applied to the segmented model prior to the virtual surgery. In order to compare the proposed osteotomy line with the conventional lines used in clinical applications, virtual surgery simulations were performed and callus tissues were modelled for each scenario. The comparison of the success of each osteotomy line was carried out based on the occlusion of the teeth. Results: The osteotomy line determined using the method proposed in this study has resulted in far less malocclusion than the conventional method. Namely, any angular deviation from the optimum osteotomy line determined in this study might result in deep-bite or open-bite. On the other hand, the finite element analysis results have indicated that this deviation also negatively affects the callus stability. Conclusion: In order to achieve a better MDO treatment in terms of occlusion of the teeth and the callus stability, the location of the osteotomy line and the distractor position can be computationally determined. The results suggest that MDO protocol developed in this study might be used in clinic to achieve a better outcome from the MDO treatment.
AtıfScopus7WoS4İncele - MakaleYalnız künye2018Influence of high pressure torsion-induced grain refinement and subsequent aging on tribological properties of Cu-Cr-Zr alloy
Purcek, G.; Yanar, H.; Shangina, D.V.; Demirtas, M.; Bochvar, N.R.; Dobatkin, S.V.
Effects of ultrafine grain formation via high pressure torsion (HPT) and precipitation during aging on the microstructure, mechanical and tribological properties of a Cu-Cr-Zr alloy have been investigated systematically. HPT results in the formation of ultrafine-grained (UFG) structure in the alloy with an average grain/subgrain size of 155 nm which leads to remarkable improvement in its hardness and strength along with a reduction in elongation to failure. Aging of UFG alloy brings about further strengthening due to the precipitation. UFG formation by HPT increases substantially the wear resistance of Cu-Cr-Zr alloy and reduces the friction coefficient. The highest wear resistance and the lowest friction coefficient are obtained on the sample processed by HPT and subsequent aging. The dominant wear mechanism of the alloy varies depending on the applied processes. Adhesion with smearing is the predominant wear mechanism for the initial (warm extruded) samples having coarse-grained (CG) structure. UFG samples show less adhesional effect with less smearing, and a higher tendency to the formation of cracks, abrasion and delamination seem to be dominant in those samples. Oxidative wear mechanism is also operative in both CG and UFG alloy samples. It may be concluded from this study that a combined process including UFG formation by HPT and subsequent precipitation by artificial aging provides a simple and effective processing procedure for improving the strength, hardness and wear resistance of Cu–Cr–Zr alloys without modification of the chemical composition.
AtıfScopus96WoS91İncele - MakaleYayıncıda açık erişim2018Synthesis and characterization of Zn-doped Mn3O4 thin films using successive ionic layer adsorption and reaction technique: Its structural, optical and wettability properties
Bayram, Ozkan; Ertargin, Mehmet Emrah; Igman, Erdal; Guney, Harun; Simsek, Onder
In this study, it is aimed to obtain Zn doped Mn3O4 (manganese oxide) nanostructured thin films on the soda lime glass substrates by successive ionic layer adsorption and reaction technique. The tetragonal crystal structure of the all thin films was detected using XRD spectroscopy. The average crystallite size of undoped Mn3O4 thin films was calculated to be 29 nm and for Zn-doped thin films, this value decreased to 23 nm with increasing Zn concentration. Characteristic peaks for thin films were also confirmed by RAMAN spectroscopy. The morphological structures of zinc-doped manganese oxide nano-sheets thin films were revealed by SEM. Using UV–Vis spectroscopy, it was found that the optical band gap of Mn3O4 thin films decreased from 2.05 to 1.73 eV with Zn doping. It has also been understood from the wettability analyzes of thin films that all thin films have a hydrophilic character. From all these analyzes, it is thought that the Zn doped Mn3O4 thin films have the potential to be used in supercapacitor applications.
AtıfScopus25WoS22İncele - MakaleYalnız künye2018Energy and exergy analysis of a solid-oxide fuel cell power generation system for an aerial vehicle (ISSA- 2015–139)
Genç, Gamze; Sarikoç, Selçuk
This paper presents the performance of the solid-oxide fuel cell/gas turbine hybrid power generation system with heat recovery waste unit based on the energy and exergy analyses. The effect of air inlet temperature and air/fuel ratio on exergy destruction and network output is determined. For the numerical calculations, air inlet temperature and air fuel ratio are increased from 273 to 373 K and from 40 to 60, respectively. The results of the numerical calculations bring out that total exergy destruction quantity increases with the increase of air inlet temperature and air/fuel ratio. Furthermore, the maximum system overall first and second law efficiencies are obtained in the cases of air inlet temperature and air/fuel ratio equal to 273 K and 60, respectively, and these values are 62.09% and 54.91%.
AtıfScopus9İncele - MakaleYalnız künye2018Determination of effective constitutive parameters of inhomogeneous metamaterials with bianisotropy
Hasar, Ugur Cem; Buldu, Gul; Kaya, Yunus; Ozturk, Gokhan
A recursive algorithm is proposed to accurately extract the electromagnetic parameters of isotropic/bianisotropic metamaterial (MM) slabs of inhomogeneous structures. The algorithm is based on the recursive calculations of measured/ simulated forward and backward scattering (S-) parameters from previously extracted wave impedances and refractive indices of each homogeneous layer (except the analyzed intermediate layer) by a suitable retrieval method. There are two main advantages of our proposed method over existing extraction algorithms. First, it could retrieve the electromagnetic parameters of both isotropic and bianisotropic MM slabs. Second, it is applicable for electromagnetic parameter extraction of inhomogeneous structures. For validation of our method and assessing its accuracy over existing extraction methods, we used the simulation results of various inhomogeneous structures constructed by different isotropic/bianisotropic MM slabs (split-ring-resonator (SRR), SRR-wire, omega, and omega-wire). For completeness, the effects of noise present in S-parameters and iterative error (by increasing the value of iteration numbers) are examined to test the robustness of the proposed algorithm.
AtıfScopus43WoS42İncele - Derleme MakaleYalnız künye2018Green roofs and facades: A comprehensive review
Besir, Ahmet B.; Cuce, Erdem
Based on United Nations Environment Program (UNEP), building sector accounts for 40% of total energy consumption. In European countries, 36% of total greenhouse gas emissions is attributed to buildings. In this respect, green roofs are considered to be one of the most appropriate sustainable solutions to resolve the urban heat island-related issues. Roofs account for nearly 20–25% of overall urban surface areas. Energy saving, thermal insulation, shading and evapotranspiration features highlight the key role of green roofs in overall thermal performance of buildings and microclimatic conditions of indoor environments. Within the scope of this research, the concept of green roofs and facades is comprehensively analysed in a holistic and thematic way. Following a historical overview of the technology, the research is split into various subfields such as energy saving in buildings through greenery systems, multifunctional thermal benefits including evapotranspiration, thermal insulation, shading and thermal comfort features, evaporative cooling for reducing cooling demand and minimising wind driven convection losses. The results achieved from the literature survey clearly indicate that green roofs and facades are key solutions to mitigate building-related energy consumptions and greenhouse gas emissions. According to the previous works, heat flow through the building roofs in summer can be reduced by approximately 80% via green roofs. The green roofs are reported to consume less energy in the range of 2.2–16.7% than traditional roofs during summer time. A similar tendency is observed for the winter season depending on regional and climatic conditions. The temperature difference between conventional and greens roofs in winter is found to be about 4 °C, which is remarkable. Energy demand of buildings in summer is highly dependent on the plant intensity as it is reported to be 23.6, 12.3 and 8.2 kWh/m2/year for extensive, semi-intensive and intensive greenery surface, respectively. Greenery systems are also capable of providing thermally comfortable indoor and outdoor conditions. It is underlined that the annual average accumulation of CO2 reaches the level of 13.41–97.03 kg carbon/m2 for 98 m2 of vertical greenery system. The results of this research can be useful for dwellers, builders, architects, engineers and policy makers to have a good understanding about the potential of green roofs and facades to mitigate building-related energy consumptions and carbon emissions in a renewable, sustainable, energy-efficient and cost effective way.
AtıfScopus547İncele - Kitap BölümüYalnız künye2018Solar calculations of modified arch (Semi-spherical)-type greenhouse system for Bayburt City
Uğur, Çakir; Erol, Şahin; Kemal, Çomakli; Ayşegül, Çokgez Kuş; Aloui, F; Dincer, I
Solar energy is thought as the main source of all energy sources in the world, and it can be used in many applications like agricultural areas, heating-cooling or electricity production directly or indirectly. Greenhousing is the first one of the agricultural activities that solar energy can be used directly in. Greenhouses offer us suitable conditions which can be controlled easily for the growth of the plant, and they are made by using a covering material that allows the sunlight to enter into the system. Covering material can be glass, fibre glass, plastic or another transparent element. This study investigates the solar energy usability rates and solar energy benefitting rates of a semi-spherical (modified arch)-type greenhouse system according to different orientations and positions which exist under climatic conditions of Bayburt. In the concept of this study, it is tried to determine the best direction and best sizes of a semi-spherical greenhouse to get the best solar benefit from the sun. To achieve this aim, a modelling study is made by using MATLAB. However, this modelling study is run for some determined shapes and greenhouses, and it can be used for different shaped greenhouses or buildings. The basic parameters are determined as greenhouse azimuth angle, the rate of size of long edge to short and seasonal solar energy gaining of greenhouse.
AtıfScopus1İncele - MakaleYalnız künye2018High temperature superplasticity and deformation behavior of naturally aged Zn-Al alloys with different phase compositions
Demirtas, M.; Kawasaki, M.; Yanar, H.; Purcek, G.
Two Zn-Al alloys, eutectoid Zn-22Al and dilute Zn-0.3Al, were processed through equal-channel angular pressing (ECAP). The ECAP-processed alloys were subjected to long-term natural aging at room temperature for 120 days in order to investigate the effect of long-term natural aging on high-temperature superplasticity and the deformation behavior of these alloys. The grain size of the Zn-22Al alloy increased from 200 nm after ECAP to 400 nm after the natural aging process. The Zn-0.3Al alloy with a grain size of 1.3 µm after ECAP demonstrated a reasonably stable microstructure with the grain size of ~ 1.7 µm after long-term natural aging. The naturally aged ultrafine-grained (UFG) Zn-22Al alloy showed an excellent superplastic elongation of about 1800% at 200 °C. Grain boundary sliding was determined as the dominant deformation mechanism in this alloy. On the contrary, a considerably low elongation to failure of 230% was recorded in the naturally aged fine-grained (FG) Zn-0.3Al alloy at 150 °C, and dislocation creep was evaluated as the main deformation mechanism for this alloy. Detailed microstructural analyses showed that the FG Zn-0.3Al alloy was exposed to grain boundary corrosion during the natural aging process due to the presence of Al precipitates at grain boundaries whereas such formation was not observed in the UFG Zn-22% Al alloy. Grain boundary sliding was hindered by grain boundary corrosion and the cavity nucleation at the corroded grain boundaries caused a premature failure leading to such a low elongation in the Zn-0.3Al alloy.
AtıfScopus30WoS30İncele - MakaleYalnız künye2018Investigating 5-hydroxymethylfurfural formation kinetic and antioxidant activity in heat treated honey from different floral sources
Turkut, G. Merve; Degirmenci, Atiye; Yildiz, Oktay; Can, Zehra; Cavrar, Sevda; Yaylaci Karahalil, Fatma; Kolayli, Sevgi
The quality and biochemical properties of honey are affected by heating or during storage period. The most important biochemical reaction that occurs in this process is the Maillard reaction. HMF (5-hydroxymethylfurfural) is one of the major intermediate products in the Maillard reaction that can lead to quality reduction in heated honey. In this study, the effect of heating on the antioxidant activity, and colour values as Maillard reaction indicators of three different botanical honeys were investigated; the HMF formation was also determined. Temperatures of 50, 70 and 80 °C were applied on the honeys between 0 and 48 h. Total phenolic content, ferric reducing/antioxidant power and scavenging of 2,2-diphenyl-1-picrylhydrazyl free radical assays are used to determine the antioxidant capacity. Results showed that the formation of HMF and the antioxidant properties of honeys were significantly increased during the heating process. Pure HMF compound also showed lower antioxidant activity. The formation of HMF has higher degree of linearity in the fit of the zero order reaction and also it was the highest in the chestnut honey. Furthermore, it was found that as the biochemical value of the honeys increased, the HMF formation decelerated.
AtıfScopus45WoS35İncele - MakaleYalnız künye2018Conjugated polythiophene/Ni doped ZnO hetero bilayer nanocomposite thin films: Its structural, optical and photoluminescence properties
Bayram, Ozkan
In this study, synthesis and characterization of plasma polymerized Thiophene/ Nickel doped Zinc Oxide (PTNZO) bilayer nanocomposite films were carried out. Nickel doped zinc oxide (NZO) thin films were obtained by magnetron sputtering technique on glass substrates at 40 W Radio Frequency (RF) power. Plasma polymerized Thiophene (PT) thin films were deposited on the NZO thin films obtained on the glass substrate by Radio Frequency (RF) plasma polymerisation technique. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), FTIR and Photoluminescence (PL) analyzes were performed for the characterization of PTNZO hetero bilayer nanocomposite films. In the XRD spectra of PTNZO bilayer nanocomposite thin films, (002) planes were determined as the most basic peak, and it was determined that the intensity of this peak, changed depending on the RF power of polymer thin films. Optical properties of nanocomposite thin films such as transmittance, absorbance and optical band gap were determined by UV–Vis spectroscopy. Optical band gap for PTNZO nanocomposites were 2.72 eV, 2.34 eV, and 2.45 eV, respectively, with increasing RF power. For NZO thin films, this value is 3.12 eV. The optical band gaps calculated from the absorption and transmittance spectra obtained using UV–visible spectroscopy had a good compatibility with those of the optical band spectra calculated from the PL spectra. The tetragonal wurtzite structure of the NZO thin films was examined by SEM analysis. The grain size of NZO nanostructure was found to be approximately 59 nm.
AtıfScopus9İncele - MakaleYalnız künye2018Melissopalynological analysis for geographical marking of Kars honey; [Kars balının coğrafi İşaretlemesi İçin melissopalinolojik analiz]
Çelemli, Ömür Gençay; Özenirler, Çiğdem; Bayram, Nesrin Ecem; Zare, Golshan; Sorkun, Kadriye
In this research, the melissopalynological analysis of honey samples collected from Kars city located in the East Anatolian Region of Turkey was conducted for geographical marking. Within this context, melissopalynological analyses of 100 honey samples determined by sampling method were collected from eight districts of Kars in Eastern Anatolia Region of Turkey were done, to determine the nectarous source plants of Kars honey. As a result of melisopalynological analyses carried out in 100 honey samples; pollens of the taxa belonging to Apiaceae, Asteraceae, Berberidaceae, Betulaceae, Brassicaceae, Boraginaceae, Campanulaceae, Caryophyllaceae, Chenopodiaceae, Cistaceae, Cyperaceae, Dipsacaceae, Ericaceae, Fabaceae, Iridaceae, Lamiaceae, Liliaceae, Malvaceae, Onagraceae, Papaveraceae, Plantaginaceae, Poaceae, Polygonaceae, Ranunculaceae, Rhamnaceae, Rosaceae, Rubiaceae, Rutaceae, Salicaceae and Scrophulariaceae families were detected at different rates. Almost in all of the honey samples, Lotus corniculatus (in 99 samples), Onobrychis radiata (in 99 samples), Trifolium nigrescens (in 88 samples) from Fabaceae family and pollens of Echium vulgaris (81 samples) and Myosotis lithoospermifolia (15 samples) taxa from the Boraginaceae family, were found in honey samples. Onobrychis radiata pollen was the most intensely observed one among these samples (in dominant, secondary, minor, trace amounts). The total number of pollens (TPN-10) in 10 grams of honey were also detected during the melissopalynological analyses. TPN-10 values minimum: 226, maximum: 481157 and mean: 31678 were detected and the pollen abundance of the honeys are classified as good category. Kars is an important province for beekeeping with floral variety. As a result of this study, the first step of the geographical marking studies of Kars’ honey was completed.
AtıfScopus17İncele - MakaleYalnız künye2018A new method for determination of dynamic stability of self-consolidating concrete: 3-Compartment sieve test
Gökçe, H. Süleyman; Andiç-Çakır, Özge
There are many standard test methods and applications to determine or estimate the workability of fresh concrete mixtures, most of them are focused on highly flowable concrete mixtures. Due to its high flowability, self-consolidating concrete (SCC) is much more vulnerable to segregation compared to conventional concrete mixtures. Thus, researchers have been working on adopting dynamic and static test methods for determination and improvement of segregation stability of those mixtures. In this study, the different segregation test methods presented in the literature were assessed and a novel method, i.e. 3-compartment sieve test, was introduced. The dynamic stability of fresh self-consolidating concrete mixtures was evaluated by the suggested test method after slump-flow and J-Ring tests. In conclusion, the developed new method is recommended for determination of segregation in SCC due to satisfactory concurrency of results with those of visual stability index test (0.67 ≤ R2 ≤ 0.90) and sieve segregation resistance test (0.83 ≤ R2 ≤ 0.90), respectively.
AtıfScopus23WoS19İncele - BildiriYalnız künye2018Threshold effect on particle tracking algorithms
Yücel, Harun; Velu, Sabareesh K. P.; Oktem, Y.; Ozturk, F.C.; Dogan, G.S.; Guzelcimen, F.; Akkus, B.
Automated particle tracking algorithms are widely used by soft matter physicists as a research tool to detect and construct the trajectories of micron-sized particles in ffuids. Analyzing these trajectories will uncover the physics of the investigated particles mainly on the type of motion they undergo making them suitable for potential applications. A plethora of methods has been proposed and used for detection and tracking. In this work, we examine the performance of two commonly used tracking algorithms in terms of threshold dependencies in digital video images. One of them is the centroid method (CM), a well-known and used algorithm and the other is radial symmetry method (RSM) which is recently proposed. Here, we generate the synthetic digital video images consisting of randomly placed multiple particles and compare the absolute errors on the particle detection by varying threshold values. Our results suggest that both algorithms show dependence on the threshold value and on comparison RSM algorithm performs better than the CM algorithm when the noise level is zero. Moreover, the measured absolute errors show a strong dependence on threshold values when noise levels are increased (up to 20) especially for the RSM algorithm.
AtıfScopus1WoS1İncele - MakaleYalnız künye2018Real-time implementation of self-tuning regulator control technique for coupled tank industrial process system
Ayten, Kagan Koray; Dumlu, Ahmet; Kaleli, Aliriza
This article presents the self-tuning regulator control technique for a coupled tank liquid level system that often used in industry. An autoregressive with exogenous model has been used as the liquid process model with the self-tuning control implementation in order to track the desired tank level trajectories with disturbances and uncertainties of the system dynamics. The designed self-tuning controller has been sensitive to parameter variations of the nonlinear coupled tank system. The parameters of the proposed controller are periodically updated themselves during the process by means of online recursive least square method with the forgetting factor algorithm. In this way, the parameter variations and unwanted disturbances of the system are eliminated in real-time application. In order to demonstrate the efficiency of the self-tuning regulator control technique, the real-time studies have been executed. The obtained experimental results demonstrated that the proposed controller gives the better trajectory tracking performance and smaller magnitude in overshot and undershot than the designed classical proportional–integral and sliding mode controllers.
AtıfScopus11İncele - MakaleYalnız künye2018Drug likeness scoring and quantitative structure anaplastic lymphoma kinase (ALK) inhibitors activities relationships of pyrazolone derivatives
Ouadah, Karim; Tchouar, Noureddine; Belaidi, Salah; Oukil, Oualid; Cinar, Mehmet
Series of twenty-four compounds was the field for applying multi-parameter optimization (MPO) methods and qualitative approximations of structural activity relationships in order to determine the role of various physico-chemical and quantum descriptors used in QSAR modeling as independent variables. Anaplastic lymphoma kinase (ALK) inhibitory activity was considered as a component in this study. In order to illustrate the quantitative relationships between the molecular descriptors and the activity of pyrazolone derivatives, we have applied a multiple linear regression (MLR) procedure. By adopting cross-validation with the leave-one-out method, we could estimate the predictability of models. Our results suggest a QSAR model based on the following descriptors: S, V, LogP, POL, Ref, HOMO, LUMO, E, , HBA, PSA and NRB, for the inhibitory activities against ALK. Results show high correlation between experimental and predicted activity values, indicating the validation and the good quality of the QSAR model.