Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(116)
- Şahin, Engin(48)
- Kaya, Yunus(46)
- Özen, Soner(46)
- İspirli, Hümeyra(45)
- Pat, Suat(44)
- Şenay, Volkan(42)
- Korkmaz, Şadan(36)
- Yilmaz, Mustafa Tahsin(33)
- Kutlu, Naciye(32)
- Cuce, Erdem(31)
- Öner, Erdal(31)
- Artar, Musa(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Mercan, Emin(28)
- Bayraktar, Bülent(27)
- Bayram, Sinan(27)
- Can, Zehra(25)
- Ecem Bayram, Nesrin(25)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Ayata, Ümit(21)
- Bayram, Ozkan(21)
- Dirican, Ebubekir(20)
- Abdioglu, Murat(19)
- Ayazoglu, Rabil(19)
- Birinci, Ahmet(19)
- Kamiloğlu, Aybike(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Tozlu, Alperen(18)
- Gul, Volkan(15)
- Hasar, Ugur C.(15)
- Kadakal, Mahir(15)
- Sagdic, Osman(15)
- Ergün, Mustafa(14)
- Kadakal, Huriye(14)
Yayınlar
- MakaleYalnız künye2015Scopus SJRQ3Some physical properties of the SiGe thin film coatings by thermionic vacuum arc (TVA)
Özen, Soner; Pat, Suat; Şenay, Volkan; Korkmaz, Şadan; Geçici, Birol
SiGe thin films were deposited on glass and PET substrate by the thermionic vacuum arc (TVA) method for the first time. TVA is an anodic plasma generator which works in high vacuum conditions. Highly pure and quality films can be deposited on different substrates by means of this method. In order to characterize the produced films, X-ray diffraction, field emission scanning electron microscope (FESEM), atomic force microscope (AFM), energy dispersive X-ray spectrometer (EDX), optical tensiometer, UV-Vis spectrophotometer and spectroscopic ellipsometer (SE) devices were used. The obtained XRD peaks at 47° and 75° are described to the reflections of (220) and (331) planes of Ge or Si. According to the measurement results, substrates materials are affect the surface and optical properties of the deposited SiGe layers. SiGe coated samples with low optical band gaps exhibit low transparency and high absorption. The structures are homogenous and less rough.
AtıfScopus15WoS16OpenAlex14
İncele - MakaleAçık Erişim2015Scopus SJRQ2Optimum design of composite steel frames with semi-rigid connections and column bases via genetic algorithm
Artar, Musa; Daloʇlu, Ayşe T.
A genetic algorithm-based minimum weight design method is presented for steel frames containing composite beams, semi-rigid connections and column bases. Genetic Algorithms carry out optimum steel frames by selecting suitable profile sections from a specified list including 128 W sections taken from American Institute of Steel Construction (AISC). The displacement and stress constraints obeying AISC Allowable Stress Design (ASD) specification and geometric (size) constraints are incorporated in the optimization process. Optimum designs of three different plane frames with semi-rigid beam-to-column and column-to-base plate connections are carried out first without considering concrete slab effects on floor beams in finite element analyses. The same optimization procedures are then repeated for the case of frames with composite beams. A program is coded in MATLAB for all optimization procedures. Results obtained from the examples show the applicability and robustness of the method. Moreover, it is proved that consideration of the contribution of concrete on the behavior of the floor beams enables a lighter and more economical design for steel frames with semi-rigid connections and column bases.
AtıfScopus26WoS25OpenAlex21İncele - MakaleAçık Erişim2015Scopus SJRQ2Characterization of functional properties of enterococcus faecium strains isolated from human gut
İspirli, Humeyra; Demirbaş, Fatmanur; Dertli, Enes
The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut-and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests.
AtıfScopus41WoS37OpenAlex42
İncele - MakaleAçık Erişim2015Scopus SJRQ2Experimental study to remediate acid fuchsin dye using laccase-modified zeolite from aqueous solutions
Kalkan, Ekrem; Nadaroglu, Hayrunnisa; Celebi, Neslihan; Celik, Hulya; Tasgin, Esen
This paper studies, the removal of acid fuchsin dye from aqueous solutions using zeolite natural material after its modification with laccase from Russulaceae (Lactarius volemus). Batch adsorption experiments were performed as a function of pH, contact time, temperature, and adsorbent dosage. The optimum results were obtained at pH 5, contact time of 60 min, temperature of 60ºC, and an adsorbent dosage of 1.5 mg/mL. The isotherm studies show that the adsorption experimental data are fitted well by Langmuir isotherm model. The adsorption capacity found is 31 mg/g. The kinetics of AFD adsorption on LMZ is best described with the pseudo-first-order kinetics model. Thermodynamic parameters including Gibbs free energy, enthalpy, and entropy changes indicate that the adsorption of Acid Fuchsin dye onto laccase-modified zeolite is feasible, spontaneous, and exothermic. The results show that laccase-modified zeolite can be used as an alternative lowcost adsorbent for dye removal from aqueous solutions.
AtıfScopus33WoS27OpenAlex29İncele - MakaleYalnız künye2015Scopus SJRQ1Spectral features, electric properties, NBO analysis and reactivity descriptors of 2-(2-Benzothiazolylthio)-Ethanol: Combined experimental and DFT studies
Srivastava, Ruchi; Sinha, L.; Karabacak, M.; Prasad, O.; Pathak, S.K.; Asiri, A.M.; Cinar, M.
(Chemical Equation Presented). Quantum chemical calculations of ground state energy, geometrical structure and vibrational wavenumbers, nuclear magnetic behaviors, electronic absorption spectra along with the nonlinear optical properties of 2-(2-benzothiazolylthio)-ethanol (BTZTE) were carried out using density functional (DFT/B3LYP) method with 6-311++G(d,p) as basis set. The FT-IR and FT-Raman spectra were measuredinthe condensed state. The fundamental vibrational wavenumbers as well as their intensities were calculated, and a good correlation between experimental and scaled calculated wavenumbers was accomplished. The electric dipole moment, polarizability and the first hyperpolarizability values of the BTZTE were calculated at the same level of theory and basis set. The results show that the BTZTE molecule possesses nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization was analyzed using natural bond orbital (NBO) analysis. UV spectrum of the studied molecule was recorded in the region 200-500 nm and the electronic properties were predicted by time-dependent DFT approach. The calculated transition energies are in good concurrency with the experimental data. 1H nuclear magnetic resonance (NMR) chemical shifts of the title molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The thermodynamic properties of the studied compound at different temperatures were calculated. Global and local reactivity descriptors were computed to predict reactivity and reactive sites on the molecule.
AtıfScopus23WoS28OpenAlex28İncele - MakaleAçık Erişim2015Scopus SJRQ3Experimental and numerical investigation of a novel energy-efficient vacuum glazing technology for low-carbon buildings
Cuce, Erdem
In this study, a recently developed innovative window technology called vacuum tube window is introduced, and its performance assessment is presented through an experimental and numerical research. The novel design of vacuum tube window consists of evacuated tubes surrounded by Argon as inert gas to eliminate conductive and convective effects inside the window and thus to produce a building element with remarkably low overall heat transfer coefficient (U-value). Heat transfer inside the window was modelled via a reliable commercial computational fluid dynamics software ANSYS FLUENT. The accuracy of simulations was verified by environmental chamber tests. For the vacuum tube diameter of 28 mm, an excellent agreement between experimental and numerical data was achieved. For different values of design parameters such as pane thickness, tube thickness, tube diameter and Argon gap, total heat loss and U-value of the vacuum tube window and optimum data were evaluated. Optimum tube diameter was found to be 60 mm in terms of thermal performance characteristics, cost, lightness and aesthetic issues. It is concluded that the vacuum tube window is able to provide a U-value lower than 0.40 W/m2K, which is very promising for both retrofitting of existing buildings and new-build applications.
AtıfScopus16WoS11OpenAlex18İncele - MakaleYalnız künye2015Scopus SJRQ1Thermal loop test to determine structural changes and thermal stability of creamed honey: Rheological characterization
Karasu, Salih; Toker, Omer Said; Yilmaz, Mustafa Tahsin; Karaman, Safa; Dertli, Enes
This study was the first attempt to understand if thermal stability of any food product during storage could be determined. In this respect, a novel method, namely, the thermal loop test was used to determine structural changes and thermal stability of creamed honey in this study. The novelty of this method was that thermal stability of a product is tested within a number of thermal cycles over a determined range of temperature. Creamed honey was characterized in terms of physicochemical, thermomechanical and rheological properties. It showed non-Newtonian thixotropic behavior at all temperature levels (10, 25 and 40 °C). Time-dependent flow behavior was successfully defined by Weltman and second order structural models. Hysteresis loop area depended on temperature and decreased with increase in temperature. Creamed honey had liquid-like structure, showing that it had more pronounced viscous nature than elastic nature (G″ > G′). Temperature sweep tests were conducted to determine temperature dependency of η50, G′ and G″ values using Arrhenius equation. These test results confirmed the thermal stability test results, revealing that thermal loop test can be an accurate method to determine thermal stability of similar food products, as a new information. Relative structural index value (Δ) increased with number of thermal loop, suggesting that creamed honey had low thermal stability and showed a great structural change by the thermal stress applied between 5 °C and 50 °C. These results suggest that crystallized honey be abstained from large temperature fluctuations to avoid from irreversible changes in rheological characters; thus, to maintain spreadability.
AtıfScopus45WoS43OpenAlex47İncele - MakaleAçık Erişim2015Scopus SJRQ2Decontamination of Escherichia coliO157: H7 and Staphylococcus aureus from Fresh-Cut Parsley with Natural Plant Hydrosols
Törnük, Fatih; Dertli, Enes
The inhibitory effects of sage, rosemary, oregano and thyme hydrosols were evaluated against Escherichia coliO157:H7 and Staphylococcus aureus inoculated on parsley at high and low concentrations. Following the pathogen inoculations, parsley samples were washed with the hydrosols and sterile tap water as a control for 0, 20, 40 and 60min, and reductions on pathogen counts were determined. Sterile tap water was ineffective on all conditions tested. After 20min of application, oregano and thyme hydrosols were able to significantly (P<0.05) reduce E.coliO157:H7 counts on low inoculum level, while all hydrosols showed significant reductions (P<0.05) on high inoculum levels at this period. Additional reductions on E.coliO157:H7 counts were observed with the increasing time. S.aureus was more sensitive to hydrosol treatments, and oregano hydrosol was able to completely eliminate S.aureus after 40min. In conclusion, decontamination of foodborne pathogens from fresh-cut vegetables can be achieved by hydrosol treatments.
AtıfScopus14WoS11OpenAlex16İncele - MakaleAçık Erişim2015Scopus SJRQ3Influence of RF power on optical and surface properties of the ZnO thin films deposited by magnetron sputtering
Pat, Suat; Şenay, Volkan; Özen, Soner; Korkmaz, Şadan; Geçici, Birol
The influences of the effects of sputtering power on the optical and structural properties of ZnO thin films were investigated. The ZnO layers were deposited on glass slides by RF magnetron sputtering. RF sputtering powers were adjust to 150 W and 250 W. Optical analysis and tools and methods were used for the comparison of the optical and surface properties. The results show that sputtering powers have affected the optical and surface properties. The band gap variations of ZnO thin films are observed. The samples are transparent. The roughness values of sample grown at 250 W are increased threefold in comparison with sample grown at 150 W while RF power is increased. Furthermore, surface contact angle was decreased to one-half of its values obtained at low RF power. This value is close to theoretical limit of contact angle. Obtained results show that surface properties of the layers can changed by RF power, but optical properties are slightly different.
AtıfScopus5WoS6OpenAlex6İncele - MakaleAçık Erişim2015Scopus SJRQ1Impact of the exopolysaccharide layer on biofilms, adhesion and resistance to stress in Lactobacillus johnsonii FI9785
Dertli, Enes; Mayer, Melinda J.; Narbad, Arjan
Background: The bacterial cell surface is a crucial factor in cell-cell and cell-host interactions. Lactobacillus johnsonii FI9785 produces an exopolysaccharide (EPS) layer whose quantity and composition is altered in mutants that harbour genetic changes in their eps gene clusters. We have assessed the effect of changes in EPS production on cell surface characteristics that may affect the ability of L. johnsonii to colonise the poultry host and exclude pathogens. Results: Analysis of physicochemical cell surface characteristics reflected by Zeta potential and adhesion to hexadecane showed that an increase in EPS gave a less negative, more hydrophilic surface and reduced autoaggregation. Autoaggregation was significantly higher in mutants that have reduced EPS, indicating that EPS can mask surface structures responsible for cell-cell interactions. EPS also affected biofilm formation, but here the quantity of EPS produced was not the only determinant. A reduction in EPS production increased bacterial adhesion to chicken gut explants, but made the bacteria less able to survive some stresses. Conclusions: This study showed that manipulation of EPS production in L. johnsonii FI9785 can affect properties which may improve its performance as a competitive exclusion agent, but that positive changes in adhesion may be compromised by a reduction in the ability to survive stress.
AtıfScopus201WoS179OpenAlex211İncele - DüzeltmeAçık Erişim2015Scopus SJRQ4Erratum to: “Antagonistic effects of Satureja hortensis essential oil against AFB1, on human lymphocytes in vitro” (Cytology and Genetics, (2014), 48, (5), 327, 10.3103/S0095452715010120)
Ceker, S.; Agar, G.; Alpsoy, L.; Nardemir, G.; Kizil, H.E.
AtıfOpenAlex1İncele - MakaleAçık Erişim2015Scopus SJRQ2The investigation of prevalence and risk factors associated with cyber bullying and victimization; [Siber zorbalik ve maʇduriyetin yayginliʇinin ve risk faktörlerinin ̄ncelenmesi]
Eroʇlu, Yüksel; Aktepe, Evrim; Akbaba, Sirri; Işik, Adem; Özkorumak, Evrim
The aim of this study was to examine risk factors related to cyber bullying and victimization. The study was carried out with 160 adolescents applying to the Child/Adolescent Psychiatry Outpatient Clinic of the Faculty of Medicine of Süleyman Demirel University in Isparta, Turkey. Data was collected through using the Socio-Demographic Information Form, Internet Addiction Scale, and Cyber Victim and Bullying Scale. The results of the study showed that cyber bullying was related to gender, the risk of Internet addiction, the frequency of visiting Internet cafes, adolescents' perception of their mothers' Internet skills, the daily duration of visiting social networking sites, usage of the Internet predominantly to play online games, the monthly income of the family, and the mothers' educational status. Cyber victimization, on the other hand, was found to be related to the risk of Internet addiction, the frequency of visiting Internet cafes, adolescents' perception of their mothers' Internet skills, and usage of the Internet predominantly to play online games. The results of the study were discussed in the light of relevant literature.
AtıfScopus19WoS24OpenAlex41İncele - MakaleAçık Erişim2015Scopus SJRQ3Some new records and one new species of the genus Lebertia Neuman (Acari: Hydrachnidia: Lebertiidae) from Turkey
Esen, Yunus; Erman, Orhan
In this study, water mites of the genus Lebertia Neuman, 1880 (Acari: Hydrachnidia) collected from Antalya, Artvin, Bingöl, Erzurum, Kahramanmaras, and Siirt provinces of Turkey are presented. In total, 12 species were determined. Of these, Lebertia (s. str.) marasensis sp. nov. is described as new to science, while L. (s. str.) rufipes Koenike, 1902; L. (Pilolebertia) longiseta Bader, 1955; L. (Pilolebertia) pilosa Maglio, 1924; L. (Mixolebertia) separata Lundblad, 1930; and L. (Brentalebertia) minutipalpis K. Viets, 1920 are new records for the Turkish fauna.
AtıfScopus1WoS1OpenAlex2İncele - MakaleYalnız künye2015Scopus SJRQ3Biodiversity and Landscape Use of Sea Buckthorn (Hippophae rhamnoides L.) in the Coruh Valley of Turkey; [Sanddorn (Hippophae rhamnoides L.) im Coruh-Tal (Türkei): Biologische Vielfalt und Landschaftsnutzung]
Sezen, Isik; Ercisli, Sezai; Cakir, Ozlem; Koc, Aysen; Temim, Elma; Hadziabulic, Alisa
The Sea buckthorn, one of the most important wild edible fruits widely grown in Northeastern part of Turkey, is characterized by resistance to hard environmental conditions and looks spectacular, especially in autumn and winter when it is decorated with orange berries. Climatic conditions in Northern Anatolia are suitable for the growing of the Sea buckthorn, which can be encountered in various dry areas as well as by riversides. Local people traditionally processed or preserved sea buckthorn fruits (berries). The decorative sea buckthorn shrubs/trees and berries are an important element of natural landscape in Northeastern Anatolia. The aim of the study was to define the biodiversity among trees/shrubs, berries and leaves of the Sea buckthorn accessions based on morphological and biochemical data. Results showed a high diversity among accessions in terms of plant, leaf and berry characteristics. Berry diameter, length and 100 berry weight ranged from 5.48 to 7.18 mm; 6.64 to 9.14 mm and 15 to 26 g, respectively. A wide variability of berry skin colour was observed to be yellow, light yellow, dark yellow, yellow orange, orange and dark orange. The anthocyanin content varied from 7 to 38 mg/l berry juice.
AtıfScopus14WoS11OpenAlex14İncele - MakaleAçık Erişim2015Scopus SJRQ1Numerical modeling of cold powder compaction using multi particle and continuum media approaches
Güner, Faruk; Cora, Ömer Necati; Sofuoğlu, Hasan
Numerical analysis of powder compaction process requires multi-particle modeling approach as continuum models fail to simulate the nature of process (e.g. interparticle, and particle-die interactions), accurately. This study aimed for analyzing powder compaction process utilizing 3-D finite element modeling approach along with different material models including modified Cam-Clay, Mohr-Coulomb, Shima-Oyane and von-Mises. The finite element analyses were carried out by implementing multi-particle finite element method. Moreover, continuum modeling was also performed for comparison purposes. In both cases, the compaction of spherical copper particles was analyzed at room temperature conditions. The obtained FEA results were compared in terms of equivalent stress and strain, and deformed shape. Results showed that the FE models in which von-Mises and modified Cam-clay material models were used yielded results of similar magnitude while those of Shima-Oyane and Mohr-Coulomb material models resulted in equivalent stress and strain values are in close proximity. Effect of coefficient of friction on the results was also investigated by implementing three distinct coefficients of friction ( μ= 0.1, 0.25, 0.4). It was noted that increasing friction resulted in elevated level of deformation for the particles and harsher particle-particle, and particle-die contact interactions.
AtıfScopus72WoS67OpenAlex76İncele - MakaleAçık Erişim2015Scopus SJRQ3Selective separation, preconcentration and determination of Pd(II) ions in environmental samples by coprecipitation with a 1,2,4-triazole derivative
Ozdes, Duygu; Duran, Celal; Serencam, Huseyin; Sahin, Deniz; Gundogdu, Ali; Soylak, Mustafa
A simple, sensitive, facile and low cost methodology, combined with flame atomic absorption spectrometry (FAAS), was employed to evaluate the selective separation and preconcentration of Pd(II) ions in environmental samples by using a triazole derivative as an organic coprecipitating agent without a carrier element. The developed method was systematically investigated in different set of experimental parameters that influence the quantitative recovery of Pd(II) ions. The accuracy of the method was tested by analyzing certified reference material and spike tests. The developed coprecipitation procedure has been applied to road dust, anodic slime, industrial electronic waste materials and water samples to determine their Pd(II) levels.
AtıfScopus12WoS12OpenAlex16İncele - MakaleAçık Erişim2015Scopus SJRQ2The effect of magnetic field distribution and pole array on the vertical levitation force properties of HTS Maglev systems
Ozturk, Kemal; Abdioglu, Murat; Sahin, Ercin; Celik, Sukru; Gedikli, Hasan; Savaskan, Burcu
In this paper, the levitation force measurements have been carried out by the magnetic force measurement system under both field-cooling and zero-field-cooling regimes, whereas the magnetic field distribution over the permanent-magnet guideway (PMG) was calculated by numerical analysis based on the finite-element method. It was shown in this study that the vertical levitation capability and stability of Maglev systems can be improved depending on the cooling regime, pole number, and suitable arrangement of the PMG. In this paper, it was shown that when the pole number increases, the levitation force density increases. It also appeared that the reasonable position of the supplementary permanent magnet and appropriate cooling heights are key parameters for both levitation performance and stabilization of the high-temperature superconductor (HTS) Maglev. It is believed that the numerical and experimental data in this paper are useful for relative design and practical application of HTS Maglev systems.
AtıfScopus38WoS33OpenAlex36İncele - MakaleYalnız künye2015Scopus SJRQ3AlGaAs film growth using thermionic vacuum arc (TVA) and determination of its physical properties
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
In this research, an AlGaAs film was deposited on a microscope slide by means of the thermionic vacuum arc (TVA) technique which is a novel plasma production technique. AlGaAs structures were grown by this deposition technique for the first time and this process occurred in a very short period of time. In order to characterize the produced film, nano-structural, nano-mechanical, optical, and surface properties were determined by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray diffractometer (XRD) and interferometer. According to the results of the measurements, the mean thickness value of the produced film was obtained as 1.8 μm. The band gap value was determined as 2eV from the Kubelka-Munk plot. The refractive index value was obtained as approximately 3.4. Hardness value was determined as 2 GPa from the Oliver-Pharr method. All these values are consistent with the reported values in the literature for the AlGaAs films produced by different methods. TVA technique appeared as a suitable and promising technique for the production of AlGaAs films.
AtıfScopus22WoS24OpenAlex24İncele - MakaleYalnız künye2015Scopus SJRQ1Reference-Plane-Invariant Effective Thickness and Electromagnetic Property Determination of Isotropic Metamaterials Involving Boundary Effects
Hasar, Ugur Cem; Barroso, Joaquim José; Buldu, Gul; Bute, Musa; Kaya, Yunus; Karacali, Tevhit; Ertugrul, Mehmet
It is well recognized that near-field effects become dominant when the metamaterial (MM) is in resonance. In addition, any inaccurate information of the location of reference planes, and the effective length can seriously affect the accuracy of retrieved electromagnetic properties of MMs. By considering all these issues, in this research paper, we propose a retrieval method for reference-plane invariant and thickness-independent determination of electromagnetic parameters of MM slabs involving boundary effects. Our method first accomplishes determination of effective length of MMs and calibration-plane factors using scattering parameter measurements, aside the resonance region, of two identical MMs with different lengths. Our method then incorporates near-field effects in accurate retrieval of electromagnetic properties of MMs. The method is verified by scattering parameters simulated for a homogeneous conventional material and a weakly or negligibly coupled inhomogeneous MM slab made by two metallic concentric split-ring-resonators. Consequences of an inaccurate information of reference-plane transformation factors and the value of effective lengths and of noninclusion of near field effects on the retrieved electromagnetic properties are thoroughly discussed by way of few examples to substantiate the accuracy of the proposed method.
AtıfScopus15WoS15OpenAlex15İncele - MakaleAçık Erişim2015Scopus SJRQ2Determination of the critical fraction of solid during the solidification of a PM-cast aluminium alloy
Kayikci, Ramazan; Colak, Murat; Sirin, Selcuk; Kocaman, Engin; Akar, Neset
During the solidification of aluminium alloys, a flow of the interdendritic liquid through the mushy zone plays an important role in the feedability and shrinkage-driven porosity formation. Therefore, for almost all the studies about casting modelling, a good knowledge of the mushy-zone behaviour is necessary. In this study, the limit of the mushy-zone permeability for permanent-mould (PM)-cast aluminium alloys was investigated. A novel experimental technique was developed to quantify the value of the critical fraction of solid (CFS) at which the interdendritic feeding stops. Grain-refined and non-grain-refined aluminium alloys were used to evaluate the effect of the grain size on the CFS limit of both the non-grain-refined and fully grain-refined alloys. Three different initial mould temperatures were used to find if the mould temperature has any effect on the feeding of a casting. Alloys of varying solidification intervals were also used to determine the critical fraction of solid (CFS) for the feeding limit of solidifying castings. The results showed that the CFS values for solidifying aluminium alloys may vary from 34 % to 57 % depending on the casting conditions. The results also showed that for A356 aluminium-alloy castings the CFS value is not an alloy property, yet it significantly depends on the parameters such as the grain refinement and the modification of eutectic silicon.
AtıfScopus9WoS5OpenAlex9İncele