Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(117)
- Kaya, Yunus(51)
- Şahin, Engin(48)
- İspirli, Hümeyra(47)
- Özen, Soner(46)
- Şenay, Volkan(45)
- Pat, Suat(44)
- Can, Zehra(39)
- Bayraktar, Bülent(37)
- Bayram, Sinan(37)
- Korkmaz, Şadan(36)
- Cuce, Erdem(35)
- Ecem Bayram, Nesrin(33)
- Kutlu, Naciye(33)
- Yilmaz, Mustafa Tahsin(32)
- Artar, Musa(31)
- Ertugrul, Mehmet(30)
- Öner, Erdal(30)
- Ayata, Ümit(29)
- Hasar, Ugur Cem(29)
- Esmer, Yusuf(28)
- Mercan, Emin(27)
- Cuce, Pinar Mert(26)
- Özdemir, Akın(25)
- Çolak, Murat(24)
- Bayram, Ozkan(23)
- Kamiloğlu, Aybike(23)
- Sert, Durmuş(22)
- Ayazoglu, Rabil(21)
- Abdioglu, Murat(20)
- Bayram, Nesrin Ecem(20)
- Kadakal, Mahir(20)
- Kara, Yakup(20)
- Kizil, Hamit Emre(20)
- Tozlu, Alperen(20)
- Birinci, Ahmet(19)
- Gerçek, Yusuf Can(19)
- Battal, Fetullah(18)
- Dirican, Ebubekir(18)
- Ergün, Mustafa(18)
Yayınlar
- Derleme MakaleYalnız künye2016Scopus SJRQ1Vacuum glazing for highly insulating windows: Recent developments and future prospects
Cuce, Erdem; Cuce, Pinar Mert
A comprehensive review of vacuum glazing technology from state-of-the-art developments to future prospects has been presented. The review has been conducted in a thematic way in order to allow an easier comparison, discussion and evaluation of the findings. First, a thorough overview of historical development of vacuum glazing has been given. Then, numerous experimental, theoretical, numerical and simulation works on the scope have been evaluated and the characteristic results from the said works have been analyzed. Commercial vacuum glazing products in market have been assessed in terms of several performance parameters such as overall heat transfer coefficient, visible light transmittance, solar heat gain coefficient and cost. Techno-economic and environmental aspects of vacuum glazing technology have also been discussed. It can be concluded from the results that overall heat transfer coefficient of a vacuum glazing can be reduced up to 0.20 W/m2K through optimized integrations with low-e coatings. The incomparable U-value range of vacuum glazing enables significant mitigation in energy consumption levels and greenhouse gas emissions. Retrofitting 25.6 million homes in the UK with vacuum glazing can provide a carbon abatement of about 40 million tonnes a year, which is very promising.
AtıfScopus138WoS117OpenAlex148
İncele - MakaleYalnız künye2016Scopus SJRQ1Effect of sugar beet fiber concentrations on rheological properties of meat emulsions and their correlation with texture profile analysis
Ağar, Berrin; Gençcelep, Hüseyin; Saricaoğlu, Furkan Türker; Turhan, Sadettin
The effect of sugar beet fiber (SBF) concentration on the rheological properties of meat emulsions was determined. In addition, texture profile analysis (TPA) of cooked meat emulsions was carried out to find a possible relationship between the dynamic rheological data and TPA parameters. All studied emulsions exhibited non-Newtonian, pseudoplastic behavior since apparent viscosity decreased with increasing shear rate. The Ostwald–de Waele model was successfully used to describe the flow properties of meat emulsions (R2 > 0.913). Emulsion systems were characterized as weak gel-like macromolecular dispersions with storage modulus (G′) much greater than loss modulus (G″). A modified Cox–Merz rule was applied by multiplying angular frequency with shift factors (αSF). Material stiffness parameter (Aα) calculated from complex modulus (G*) increased as SBF concentration increased. Significant correlations among the material stiffness data and TPA parameters were observed. It was concluded that TPA parameters could be predicted by using dynamic shear tests, and hence, this will make possible to save time and cost for meat processors when manufacturing a product with acceptable structural or textural characteristics.
AtıfScopus55WoS48OpenAlex66İncele - BildiriYalnız künye2016Investigation of the thickness effect to impedance analysis results AlGaN acoustic sensor
Özen, Soner; Bilgiç, Eyüp; Gülmez, Gülay; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Mohammadigharehbagh, Reza; Akkus, B.; Dogan, G.S.; Mutlu, R.B.C.
In this study, AlGaN acoustic sensors were deposited on aluminum metal substrate by thermionic vacuum arc (TVA) method, for the first time. Impedance analyses of the fabricated acoustic sensors were investigated for the determining of effect of the nano layer thickness. Thickness values are very close to each others. Fabricated sensors have been fabricated from AlGaN deposited on aluminum substrates. Gallium materials are used in many applications for optoelectronic device and semiconductor technology. Thermionic vacuum arc is the deposition technology for the variously materials and applications field. TVA production parameters and some properties of the deposited layers were investigated. TVA is the fast deposition technology for the gallium compounds and doped gallium compounds. Obtained results that AlGaN layer are very promising material for an acoustic sensor but also TVA is proper fast technology for the production.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2016Scopus SJRQ1Optical, morphological properties and surface energy of the transparent Li4Ti5O12 (LTO) thin film as anode material for secondary type batteries
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
LTO thin film was deposited for the first time on a glass microscope slide (MS) by RF magnetron sputtering technology. This method has been suitable for preparation of high-quality thin films. The surface properties of the produced film were determined by atomic force microscope (AFM). The surface of the produced film appeared smooth and homogeneous. LTO coated on MS had compact structure and low roughness. A UV-vis spectrophotometer was used to determine intensity of light passing through the samples. Thus, according to the results obtained the produced film was highly transparent. The refractive index of the LTO thin film was presented in a low MSE value by spectroscopic ellipsometry (SE) and it was about 1.5. The optical band gap (Eg) was determined by the Tauc method. The produced LTO thin film exhibited a wide band gap semiconductor property with a band gap energy of about 2.95 eV. Finally, the surface free energy of the LTO thin film was calculated from the contact angle measurements using the Lewis acid-base, OWRK/Fowkes, Wu and Zisman methods.
AtıfScopus24WoS23OpenAlex27İncele - MakaleAçık Erişim2016Scopus SJRQ1Effect of boron-containing additives on rheological properties of asphalt binder
Oruç, Şeref; Yılmaz, Bahadır; Sancak, Kemal
In this study, four novel boron-containing additives were synthesised chemically in the laboratory. The modification was performed by adding the additives, respectively, into asphalt at a certain amount by weight at the same temperature and mixing conditions. The modification mechanism and microstructure of the blends were characterised by Fourier transform infrared spectrometer and scanning electron microscopy. The variation in modified samples in comparison to base asphalt was investigated by performing the penetration, softening point, dynamic shear rheometer, amplitude–frequency–temperature sweeps and rotational viscosity tests. It was observed that the additives increased the softening point, rutting resistance, elastic properties and viscosity of asphalt. The additive synthesised with triazole borate ester octanol-sulphuric acid catalysts gave the most enhancements, relative to base asphalt.
AtıfScopus20WoS17OpenAlex22İncele - Derleme MakaleYalnız künye2016Scopus SJRQ1Toward multi-functional PV glazing technologies in low/zero carbon buildings: Heat insulation solar glass - Latest developments and future prospects
Cuce, Erdem
Heat insulation solar glass (HISG) is a recently developed multi-functional photovoltaic (PV) glazing technology to mitigate energy consumption of buildings and to provide optimum thermal comfort conditions to occupants. In essence, HISG represents an improved transparent amorphous silicon (a-Si) PV module prepared with several optimized coatings and structures. HISG differs from conventional PV glazing products by having some characteristic features such as thermal insulation, sound absorption, self-cleaning and notable energy saving. In addition, HISG has a 100% UV blocking rate and remarkably low shading coefficient, which provides desired lighting related thermal comfort conditions for indoor environments. HISG is also competitive with conventional double glazed products in market in terms of fabrication cost. In this respect, it is highly expected that HISG has a strong potential to dominate the fenestration market in the near future. In this research, a comprehensive review of HISG technology is presented. Power generation, thermal insulation, energy saving, self-cleaning, acoustic and aesthetic features of HISG are evaluated in detail through the state-of-The-art literature survey. Existing research projects on the scope and future prospects are also addressed within the scope of this study.
AtıfScopus75WoS62OpenAlex84İncele - MakaleYalnız künye2016Scopus SJRQ2Morphology, composition, structure and optical properties of CuO/Cu2O thin films prepared by RF sputtering method
Korkmaz, Şadan; Geçici, Birol; Korkmaz, S. Deniz; Mohammadigharehbagh, Reza; Pat, Suat; Özen, Soner; Şenay, Volkan; Yudar, Hafizittin Hakan
In this paper, copper oxide (CuO/Cu2O) nanocrystalline thin films were deposited by radio frequency (RF) magnetron sputtering system at 75 W and 100 W. The surface, optical, composition and structural properties of obtaining samples were characterized by using atomic force microscopy (AFM), UV–Vis spectrophotometer, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The optical band gaps of produced films were calculated as 2.05 eV and 1.83 eV for 75 W and 100 W. The layer's thicknesses were measured as 20 nm and 50 nm using a Filmetrics F20. FESEM images of the samples prove the AFM images change and also show homogeneity of thin films and variation relative to power change, thus revealed the surface of samples disturb in homogen mode. EDX results denote presence of Cu and O elements inside the deposited samples.
AtıfScopus56WoS52OpenAlex56İncele - MakaleYalnız künye2016Scopus SJRQ2In vitro inhibitory effects of palonosetron hydrochloride, bevacizumab and cyclophosphamide on purified paraoxonase-I (hPON1) from human serum
Türkeş, Cüneyt; Söyüt, Hakan; Beydemir, Şükrü
In this study, we investigated the effects of the drugs, palonosetron hydrochloride, bevacizumab and cyclophosphamide, on human serum paraoxonase-I (hPON1) enzyme activity in in vitro conditions. The enzyme was purified ~231-fold with 34.2% yield by using ammonium sulphate precipitation, DEAE-Sephadex A-50 ion-exchange chromatography and Sephadex G-200 gel-filtration chromatography from human serum. hPON1 exhibited a single protein band on the SDS polyacrylamide gel electrophoresis. The inhibition studies were performed on paraoxonase activity of palonosetron hydrochloride, bevacizumab and cyclophosphamide. Ki constants were found as 0.033 ± 0.001, 0.054 ± 0.003 mM and 3.419 ± 0.518 mM, respectively. Compared to the inhibition rates of the drugs, palonosetron hydrochloride has the maximum inhibition rate. However, inhibition mechanisms of the drugs were determined as noncompetitive by Lineweaver-Burk curves.
AtıfScopus49WoS49OpenAlex56
İncele - MakaleAçık Erişim2016Scopus SJRQ2Study of phylogenetic relationship of Turkish species of Matthiola (Brassicaceae) based on ISSR amplification
Doğan, Bekir; Çelik, Mustafa; Ünal, Murat; Sefali, Abdurrahman; Martin, Esra; Kaya, Ayla
Matthiola W.T.Aiton is a taxonomically complex genus in which there are many problems, mostly with Matthiola longipetala and M. odoratissima. Matthiola species native to Turkey were collected from various locations in Anatolia, and their DNA was isolated. Revision studies performed on the basis of molecular data obtained from studies conducted in recent years have made the phylogenetic relationships and systematic positions of the taxa more apparent and reliable. Consequently, the remaining taxonomic problems among the species have been resolved through the use of DNA-based molecular analysis methods, which, unlike phenotype studies, are not affected by environmental factors. The inter-simple sequence repeat (ISSR) fingerprinting method was used in the study because its properties were considered to be more reliable and consistent than those of the randomly amplified polymorphic DNA method. DNA fragments were amplified through the use of ISSR primers. The phylogenetic relationships among the taxa were represe ted on a dendrogram constructed through means of NTSYSpc 2.02 software. The infrageneric and intergeneric phylogenetic relationships between Matthiola and other related genera were also characterized. It was determined that the taxa Matthiola odoratissima and M. ovatifolia are separate but closely related. Moreover, it was observed that the Matthiola longipetala complex forms a separate group within the genera. Clearly, the genera Matthiola, Sterigmostemum, Strigosella, Malcolmia, and Chorispora are phylogenetically differentiated on the dendrogram.
AtıfScopus7WoS5OpenAlex6İncele - MakaleYalnız künye2016Scopus SJRQ1Energy saving potential of heat insulation solar glass: Key results from laboratory and in-situ testing
Cuce, Erdem; Cuce, Pinar Mert; Young, Chin-Huai
HISG (heat insulation solar glass) is a recently developed multi-functional glazing technology to mitigate energy consumption of buildings. HISG can generate electricity similar to conventional PV (photovoltaic) glazing products when exposed to sunlight, however it differs from them by having some extraordinary characteristic features such as thermal insulation, which is competitive with Argon filled triple glazed windows, acoustic comfort, remarkable energy saving potential and self-cleaning ability owing to TiO2 nano coating. Within the scope of this research, latest results from laboratory and in-situ testing of HISG are presented in terms of its key role in mitigating heating and cooling demand of buildings as well as clean energy generation. Lighting and thermal comfort related parameters such as shading coefficient, UV, IR and visible light intensity are also investigated through the tests conducted in real operating conditions. It is achieved from the results that instant electricity generation of HISG is 16% higher than that of standard PV glazing owing to its nano layer reflective film. Shading coefficient of HISG is only 0.136, which provides almost 80% reduction in solar heat gain compared to ordinary glazing. Indoor air temperature measured from HISG test house in summer time is very close to the ambient temperature, whereas it is found to be 14.7 °C higher in ordinary glass test house due to greenhouse effect. Annual heating and cooling demand tests indicate that HISG provides 38 and 48% energy saving in heating and cooling season, respectively.
AtıfScopus52WoS46OpenAlex56İncele - MakaleAçık Erişim2016Scopus SJRQ1Performance investigation of a jet loop membrane bioreactor for the treatment of an actual olive mill wastewater
Değermenci, Nejdet; Cengiz, İbrahim; Yildiz, Ergun; Nuhoglu, Alper
In this study, following the pre-treatment of olive mill wastewater (OMW), its treatment in a jet loop membrane bioreactor (JLMBR) was investigated. Among the pre-treatment options, the configuration composed of physical settling, cartridge filter and ceramic membrane showed the best performance in terms of investigated parameters. For the JLMBR that was fed by pretreated OMW, up to 93 and 87% removal efficiencies were achieved for the chemical oxygen demand (COD) and total phenol, respectively, at volumetric organic load (VOL) of 17.8 kg COD/m3 day. The calculated specific oxygen uptake rate (SOUR) values were in the range 7.7–34.7 g O2/kg MLVSS h. When even hydraulic retention times (HRT) values decreased by a factor of 1:24, system performance in terms of COD and total phenol removal remained almost stable. Decreasing the sludge retention time (SRT) to three days made considerable perturbations for the system performance, increasing the effluent COD and total phenol values in 900 and 80 mg/L, respectively. The JLMBR showed a high overall performance for the treatment of an actual OMW under the evaluated operational conditions.
AtıfScopus33WoS28OpenAlex33İncele - MakaleYalnız künye2016Scopus SJRQ1A novel antifungal surface-coating application to limit postharvest decay on coated apples: Molecular, thermal and morphological properties of electrospun zein–nanofiber mats loaded with curcumin
Yilmaz, Azime; Bozkurt, Fatih; Cicek, Perihan Kubra; Dertli, Enes; Durak, Muhammed Zeki; Yilmaz, Mustafa Tahsin
Coating surfaces of fruit with electrospun zein mats with functionalized antimicrobial properties can be a novel strategy to prevent fungal colonization on fruit surfaces. In this study, we tested curcumin-loaded electrospun zein nanofibers (CLZN) in terms of limitation of postharvest decay on CLZN–coated apples infected with Botrytis cinerea and Penicillium expansum. Mixtures of zein and curcumin (the curcumin amounts of 2.5 and 5 wt% based on the weight of zein powder) were electrospun to yield cylindrical and ultrafine (< 350 nm in diameter) polymeric nanofibers. In addition, molecular, thermal, zeta potential and morphological properties of the CLZN as well as their encapsulation efficiency and releasing kinetics were determined, revealing that the developed zein-based scaffolds showed high encapsulation efficiency, molecular interactions with curcumin within nanofibers, alterations in physical states of these components, smooth beadless structure and good thermal (an endothermic peak at 152 °C) and dispersion stability (− 24 mV of ζ potential) properties. In vitro antifungal activity tests conducted at 27 °C for six days showed that CLZN were effective against growth of the tested fungal pathogens, exhibiting almost 40–50% inhibition of mycelial growth of the fungal pathogens; but the antifungal effect against P. expansum was but two-fold higher than that against B. cinerea. In vivo tests conducted at 23 °C with 75% humidity for six days confirmed in vitro test results in terms of both visual inspections on uncoated and coated apples, revealing almost 50% reduction in lesion diameter measured on coated apples infected with Penicillium expansum. Our results suggest that CLZN mats open up new opportunities for a novel application of edible and biodegradable antifungal coating material with the ability to hinder fungal proliferation on coated apples during storage period. Industrial relevance We coated the surfaces of fruits with electrospun mats with functionalized antimicrobial properties to prevent fungal colonization on fruit surface. The coating of apples with curcumin-loaded zein nanoparticles (CLZNs) limited the postharvest decay caused by the fungal pathogens, Penicillium expansum and Botrytis cinerea. This study showed that by encapsulation of curcumin into zein-based nanofibers considerably increased the antifungal effectiveness of curcumin. Our results highlighted the potential use of the CLZN as an effective fungicidal coating material against P. expansum and B. cinerea and suggested that CLZNs can be promising tools to compete with synthetic fungicide counterparts of curcumin. The results of this study should be of great importance to industrial applications in terms of development of natural, but effective preservatives as alternative to synthetic ones.
AtıfScopus111WoS85OpenAlex110İncele - MakaleAçık Erişim2016Scopus SJRQ1The impact of internal aerogel retrofitting on the thermal bridges of residential buildings: An experimental and statistical research
Cuce, Erdem; Cuce, Pinar Mert
In this research, internal thermal superinsulation in residential buildings is experimentally and statistically evaluated in terms of potential thermal bridging effects. As a consequence of significant deviations in thermal resistance values in buildings at post-retrofit, large amounts of heat losses occur through non-insulated building elements such as separating walls. Therefore, it is of vital importance to determine the level of energy loss due to such thermal bridges through an internal thermal superinsulation retrofit conducted in a typical UK building. 20 mm thick fibre-silica opaque aerogel blanket is implemented internally on the walls of a test bedroom, and the heat flux from the separating wall is measured and compared for the cases of pre and post-retrofit. The results reveal that the average amount of heat loss through the non-insulated separating wall at the post-retrofit is 5.86 W/m2, whereas it is only 0.66 W/m2 at the pre-retrofit. The results are also verified through a statistical model, which is presented for the first time in literature. The novel model is capable of providing information about potential energy loss from non-insulated walls as a function of location.
AtıfScopus60WoS54OpenAlex69İncele - BildiriAçık Erişim2016Scopus SJRQ4Thermodynamic analysis of a cascade refrigeration system
Karaali, R.
There is a need for cooling by using the waste heat energy in food industry. Absorption cycles can be driven by waste thermal, geothermal, solar or industrial processes energies. In this study, cascade refrigeration system is thermodynamically modeled, and analyzed by using first law of thermodynamics, and exergy method. Thermodynamic properties such as pressure, temperature, entropy, enthalpy, exergy, mass flow rate in each stream are calculated for 50, 75, 100?C and for 0.8, 1.0, and 1.5 MPa pump pressure. A computer program is used that was prepared in FORTRAN by the author for the analyses. It is found that the compression-absorption cascade cooling cycle is appropriate for most of the kind of waste heat applications. Increase of the generator inlet heat temperature increases the generator inlet heat, the absorber outlet heat and the condenser 2 outlet heat energies and decreases the coefficient of performance of the absorption and the overall cycles. The generator heat decreases with increase of the pump pressure. Also increase of the pump pressure decreases the coefficient of performance of the absorption and the overall cycles. Increase of the pump pressure and the generator temperature decreases the exergetic coefficient of performance. Increase of the generator temperature and pump pressure increases the generator inlet exergy. It is concluded that increase of the generator temperature and the pump pressure increases the total destructed exergy of the cycle.
AtıfScopus10WoS5OpenAlex13İncele - MakaleYalnız künye2016Scopus SJRQ1Antibacterial poly(lactic acid) (PLA) films grafted with electrospun PLA/allyl isothiocyanate fibers for food packaging
Kara, Hasan H.; Xiao, Fugang; Sarker, Majher; Jin, Tony Z.; Sousa, Ana M. M.; Liu, Cheng-Kung; Tomasula, Peggy M.; Liu, Linshu
Poly(lactic acid) (PLA) fibers of submicron sizes encapsulating allyl isothiocyanate (AITC) (PfA) were made and electrospun onto the surfaces of PLA films. SEM examination confirmed the fusion of the two phases to form a bilayered fiber-grafted film after the film underwent air blowing and water washing to remove the nongrafted fibers. The fiber-grafted PLA films (PfA-g-film) retain the mechanical properties of PLA. The release of AITC from the fibers was temperature dependent. At temperatures lower than 4°C, the incorporated AITC remained within the fibers without losing activity; at room temperature, AITC released in a sustained manner over weeks. The release of AITC was also dependent on its initial concentration in the PLA electrospinning solution; samples with more AITC incorporated showed a higher release rate. PfA-g-films significantly inhibited the growth of Listeria innocua and Escherichia coli k12 when tested on package foods.
AtıfScopus48WoS36OpenAlex50İncele - MakaleAçık Erişim2016Scopus SJRQ1Effect of different processes on lamellar-free ultrafine grain formation, room temperature superplasticity and fracture mode of Zn-22Al alloy
Demirtas, M.; Purcek, G.; Yanar, H.; Zhang, Z.J.; Zhang, Z.F.
The Zn-22 wt.%Al was processed using five different selected routes including thermal, thermo-mechanical and severe plastic deformation (SPD) techniques in order to produce ultrafine grained (UFG) microstructure for achieving room temperature (RT) and high strain rate (HSR) superplasticity, and to compare the same set of the results. After all routes, the microstructural evolutions and RT uniaxial tensile tests at different strain rates ranging from 1 × 10-3 to 1 × 100 s-1 were investigated. The smallest grain size was achieved to be 300 nm after the thermo-mechanical process including conventional hot and cold rolling steps. However, the lamellar microstructure of the alloy was not completely eliminated during that process. On the other hand, equal-channel angular pressing (ECAP) as one of the SPD techniques decreased the grain size down to 400 nm with a lamellar-free microstructure. The maximum elongation value was achieved to be 330% with the sample tested at 1 × 10-3 s-1 after a thermo-mechanical process including conventional hot and cold rolling, and an aging stage between these rolling steps. It was found that lamellar-free microstructure causes higher superplastic elongation even if it has higher grain size compared to the sample having partially lamellar structure.
AtıfScopus40WoS39İncele - MakaleAçık Erişim2016Scopus SJRQ3Investigation of the cyanide leaching optimization for ultrafine grinding gold–silver ore
Birol, Onur; Uçurum, Metin
In recent years, the ultrafine grinding (UFG) process has become increasingly important for the recovery of precious metals (especially for Au and Ag) from raw ores. It is well known that cyanide leaching of gold–silver ore has been an accepted process in the world. In the current study, UFG was proposed as a pretreatment method prior to cyanide leaching of a gold–silver ore. First, the ore was crushed and ground by jaw, cone crusher, and ring mill, respectively. Particle size of ground product was 75 µm based d80. Second, the fine product was subjected to the grinding process by vertical wet stirred ball mill, and the final ultrafine product was used as leach feed material. The leach feed material had about d80 = 20 µm and d50 = 6.02 µm particle size. Some important leaching parameters were optimized by using the ultrafine powder in the study. The final leach experiments demonstrated that the recoveries of Au and Ag were 91.92% and 82.15% under optimum leaching conditions such as 150 kg/t quicklime dosage, 25% pulp density, 85°C leach temperature, 500 g/t cyanide concentration, and 90 h leaching time.
AtıfScopus11WoS10OpenAlex11İncele - MakaleYalnız künye2016Scopus SJRQ1Melt Cleanliness Comparison of Chlorine Fluxing and Ar Degassing of Secondary Al-4Cu
Çolak, Murat; Kayikci, Ramazan; Dispinar, Derya
The treatment of liquid aluminum prior to casting typically consists of purging gas and/or fluxes through the melt. By the use of several chemicals during these operations, several environmental problems can occur. Therefore, in this study, the melt cleanliness of Al-4Cu secondary alloy was investigated by comparing the use of argon degassing with or without chlorine fluxing. Reduced pressure test was used to assess the melt quality. Highest quality melt was obtained by Ar degassing with preheated graphite lance without the need to use any chemicals.
AtıfScopus14WoS11OpenAlex13İncele - MakaleYalnız künye2016Scopus SJRQ2Examination of the 8th grade students' TIMSS mathematics success in terms of different variables1
Kaleli-Yılmaz, Gül; Hanci, Alper
The aim of this study is to determine how the TIMSS mathematics success of the 8th grade students differentiates according to the school type, gender, mathematics report mark, parents' education level, cognitive domains and cognitive domains by gender. Relational survey method was used in the study. Six-hundred fifty two 8th grade students studying in the same city in Turkey participated in this study. In this study, a 45 question test that was made up by choosing TIMSS 2011 mathematics questionnaire was used as a data collection tool. Quantitative data analysis methods were used in the data analysis, frequency, percentage, average, standard deviation, independent sample test, one-way analysis of variance and post-hoc tests were applied to data by using SPSS packaged software. At the end of the study, it was determined that the school type, mathematics school mark, parents' education level and cognitive domains influenced the students' TIMSS mathematics success but their gender was a neutral element. Moreover, it was seen that schools which are really successful in national exams are more successful in TIMSS exam; students whose mathematics school marks are 5 and whose parents graduated from university are more successful in TIMSS exams than others.
AtıfScopus12WoS11OpenAlex18İncele - MakaleAçık Erişim2016Scopus SJRQ2Embedding analogical reasoning into 5E learning model: A study of the solar system
Devecioglu-Kaymakci, Yasemin
The purpose of this study was to investigate how the 5E learning model affects learning about the Solar System when an analogical model is utilized in teaching. The data were gathered in an urban middle school 7th grade science course while teaching relevant astronomy topics. The analogical model developed by the researchers was administered to 20 seventh grade students in a city of the Black Sea Region in Turkey. "The Solar System and Beyond: The space puzzle" unit was taught by using 5E learning model accompanied by analogical model during two class hours. In this case study, pre-experimental design with pre-test-post-test was used to collect data through questionnaire, reflective thinking scale, video recording, and informal observations. According to the findings of this study, the teaching intervention not only significantly increased the students' academic achievement but also improved their science process skills. The study suggests that analogies should be well-planned and deployed for teaching science courses. Furthermore, the number of the analogical models in textbooks should be increased to enrich meaningful learning for students' transition levels between concrete and abstract operational terms.
AtıfScopus16OpenAlex23İncele