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Koleksiyondaki öğeler
- MakaleYalnız künye2015Scopus SJRQ4New data on the genus Axonopsis Piersig, 1893 (Acari: Hydrachnidia, Aturidae) in Turkey
Esen, Yunus; Kaya, Yücel; Erman, Orhan
New records of the water mites of the genus Axonopsis Piersig, 1893 (Acari: Hydrachnidia, Aturidae) from Siirt Province, Turkey, are presented in this paper. Two subgenera and three species are newly recorded to the Turkish fauna, i.e. Axonopsis (Axonopsis) complanata (Müller, 1776), A. (Brachypodopsis) guadarramensis Valdecasas, 1981 and A. (Brachypodopsis) inferorum Motaş & Tanasachi, 1947. In addition, two previously reported species from Turkey, A. (Hexaxonopsis) serrata Walter, 1928 and A. (Navinaxonopsis) persica Pešić, 2004 are also found in Siirt Province.
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İncele - MakaleAçık Erişim2016Scopus SJRQ2The power of graphic organizers: Effects on students' word-learning and achievement emotions in social studies
Ilter, Ilhan
The purpose of this study was to investigate the effectiveness of three graphic organizers for teaching vocabulary and the development of the emotions-related to achievement. The study focused on the effects of different types of graphic organizers on word-learning and various emotions in social studies. This study was designed as a quasi-experimental design by utilizing a nonequivalent control group pretest-posttest design. The experimental group was instructed on vocabulary by using the Concept definition map, a Word-questioning strategy and a Circle thinking map for word-learning, while the control group was taught to use the C(2)QU [(Context (2)-Questioning-Using)] as a process of learning new vocabulary from context. The participants of this study were fourthgrade students from a state school in Bayburt, Turkey. The results indicated that the graphic organizers group was more successful than the comparison group in terms of improving general word recognition knowledge and meaningful leaps in acquisition of target word meanings. In addition, it was found that using different types of graphic organizers developed positive achievement emotions (i.e., enjoyment, hope and pride) more than contextual learning process in social studies.
AtıfScopus6OpenAlex16İncele - MakaleAçık Erişim2019Scopus SJRQ4Investigation of the relationship between the self-confidence and motivation of high school students participating school sport contests
Toktas, Sermet; Bas, Mustafa
The purpose of this study is to examine the relationships between the levels of self-confidence and motivation of high school students participating sport contests at school and the various demographic variables (gender, high school type, sport age, sports branch and sport category). In the study, survey model, which is frequently used in descriptive research method is used. The population of the study consisted of students who studied at high schools and those who attended contests in Adıyaman, while sample consisted of 856 athletes, 39% of whom were female students (334) and 61% (522) of whom were male students. To collect data for the study, personal data form, ''Motivation in Sport'' scale, which was developed by Pelletier et al. (1995) and adapted to Turkish by Pelletier et al. and ''Self-confidence'' scale developed by Akın (2007) were used. SPSS 21.00 package program was used for data analysis. Multiple regression analysis, Pearson product-moment correlation co-efficient technique, independent t-test and one-way analysis of variance were performed in the quantitative data of the research. According to the findings obtained from the study, it was determined that there was a significant relationship between demographic information and self-confidence and motivation levels. While there was a significant difference in gender self-confidence level with intrinsic and extrinsic self-confidence and high school type sports branch, there was no significant difference between sport age and sport category. A significant relationship was found between the sub-dimension of non-motivation, intrinsic motivation and extrinsic motivation, and there was no significant relationship with other independent variables such as gender, sports branch, sport category and sport age. Based on these results, it is recommended that secondary school students participate in sports competitions to have some elements that may have positive effects on their self-confidence and motivation.
AtıfScopus5OpenAlex14İncele - MakaleAçık Erişim2014Scopus SJRQ2FT-IR, FT-Raman, NMR, UV and quantum chemical studies on monomeric and dimeric conformations of 3,5-dimethyl-4-methoxybenzoic acid
Karabacak, Mehmet; Sinha, Leena; Prasad, Onkar; Asiri, Abdullah M.; Cinar, Mehmet; Shukla, Vikas K.
Extensive spectroscopic investigations along with theoretical quantum chemical studies on 3,5-dimethyl-4-methoxybenzoic acid (DMMBA) have been consummated. The fundamental vibrational transitions were addressed by experimental FT-IR (4000-400 cm-1) and FT-Raman (4000-10 cm -1) techniques and density functional calculations at B3LYP/6-311++G(d,p) and B3LYP/6-311++G(df,pd) levels of theory. The 1H, 13C and DEPT 135 NMR spectra of studied compound were recorded in deuterated dimethylsulfoxide (DMSO-d6), and compared with computed data obtained by using gauge including atomic orbital (GIAO) method. The electronic absorption spectra in methanol and ethanol solution were evaluated in the range of 200-400 nm, and TD-DFT method was chosen for computational study. The spectroscopic and theoretical results were compared to the corresponding properties for monomer and dimer structures for the most stable conformer. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Moreover, the thermodynamic and nonlinear optical (NLO) properties were evaluated.
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İncele - MakaleAçık Erişim2019Scopus SJRQ2The role of cobalt doping on the optical and structural properties of Mn 3 O 4 nanostructured thin films obtained by SILAR technique
Bayram, Ozkan; İgman, Erdal; Guney, Harun; Simsek, Onder
Cobalt doped manganese oxide thin films (Mn 3 O 4 :Co) were successfully deposited on soda lime glass substrates using SILAR technique. Mn 3 O 4 :Co thin films were characterized using XRD, SEM, Uv–VIS and Raman spectroscopy. The XRD spectra showed that thin films had substantially Hausmannite crystal structure. The preferential orientation of the pure and 0.5 at.% Co doped manganese oxide thin films (Mn 3 O 4 ) was (002), but with increasing Co doping, it was detected that this preferential orientation shift towards the (211) plane. The absorbance, transmittance and optical band gap of the Mn 3 O 4 :Co thin films were determined using Uv–Vis spectroscopy and these properties of the thin films differed considerably due to cobalt doping. The optical band gap of pure Mn 3 O 4 thin films was 2.00 eV, but on the other hand, due to the Co doping this value increased before and then decreased slightly. Optical transmittance of Mn 3 O 4 :Co films increased from 60% to 72% with the effect of Co doping. A1g mode, which is the characteristic vibration peak of Mn 3 O 4 films, was confirmed for pure and doped Mn 3 O 4 thin films at a wavelength of 658 nm.
AtıfScopus26WoS24OpenAlex25İncele - MakaleAçık Erişim2019The effect of VR and traditional videos on learner retention and decision making
Yildirim, Gurkan; Yildirim, Serkan; Dolgunsoz, Emrah
Virtual reality (VR) as computer-mediated 3-D environments including real-life situations presented via different tools in which users can interact effectively with visuals. This study is significant as it primarily aimed to investigate effects of VR on retention by comparing it with traditional 2-D videos. The main aim of this study is to compare the effect of VR and 2-D videos on learner retention and decision making. About 18 students from the Department of English language teaching in an age range of 18-20 (nine males and nine females) voluntarily participated in this study and took course credits. As all participants were tested under the same two conditions in different time periods; repeated measures were chosen for statistical analysis. It can be inferred that both technologies have similar effects on short-term retention and VR does not provide any extra retention performance. However, VR was found to have a significant effect on long-term retention.
AtıfScopus18İncele - Derleme MakaleYalnız künye2016Nasreddin Hodja tales may inspire Turkish foreign language gifted and talented students to speak better English
Yurtbaşi, Metin
This study deals with a special methodology to meet the special needs of Turkish gifted and talented students (GTS) in terms of improving their English oral proficiency. Most GTS are known to have been born also "gifted in languages". Their language awareness shows by their "communicative skills, creative flair and arguing and reasoning". Their skill in using their native language reflect in their talents in foreign languages by their "strong desire to put language pieces together by themselves, by their creativity and imagination, picking up new words and structures very quickly, constantly asking questions and showing an intense interest in the cultural features of the new language they are learning." So benefitting from these talents they could easily be oriented to fine-tune their pronunciation and intonation in acceptable norms of phonetics. Turkish GTS having greater ease in learning new skills than their peers and are not usually satisfied with the usual methods and curriculum which do not fit to their vision of perfection at their own pace. The official foreign language training they are offered lacks the method by which they can learn to speak clearly and effectively, which is a skill they need to acquire in order to communicate orally with the rest of the world. Therefore they must be trained in new approaches to bring their proficiency on that line up to higher standards. In order to compensate this vital gap, such GTS need to learn first a special technique called "IPA transcription reading" and practice on relevant materials. In this innovative approach, students first acquire an awareness of the individual sounds and speech rhythm of the target language, i.e. English and practice on them by reading aloud texts written in IPA codes accompanied by their sound recordings and have their performance monitored by their speech instructions until perfection is reached. As for the drilling material to be chosen humor has been found great advantage, as it makes learning easier. The best known Turkish philosopher Nasreddin Hodja's satirical tales, traditionally a great source of inspiration for Turks, has been considered as a great source for such activities. By working hard on the transcriptions Hodja tales, students find not only to express themselves in English more clearly, understandably and fluently, their audience but also their conversation became wiser and more humourous. Because a sense of humor in conversation makes both speakers and listeners feel better as it smoothes out their interactions as a social lubricant. Those GTS grasping the correct norms of English pronunciation after much drilling on transcription are expected to speak English more efficiently and confidently than earlier and than their peers not undergone such training. The desired outcome will of course be achieved through constant practice and monitoring their performances.
AtıfScopus1OpenAlex2İncele - 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 - MakaleYalnız künye2014Scopus SJRQ1Power analysis of multilayer structures composed of conventional materials and bi-anisotropic metamaterial slabs
Hasar, Ugur Cem; Bute, Musa; Barroso, Joaquim J.; Sabah, Cumali; Kaya, Yunus; Ertugrul, Mehmet
In this paper, we analyze wave propagation properties (transmitted, reflected, and absorbed powers) of composite multilayer structures consisting of bi-anisotropic metamaterial (MM) slabs and conventional isotropic materials. We also separately investigate the propagation properties of bi-anisotropicMMslabs and conventional materials to better interpret the results. We consider two different bi-anisotropic MM slab structures composed of only splitring- resonators (SRRs) and composing SRRs and a rod. In the analysis, we apply the well-known transfer matrix method to obtain transmitted, reflected, and absorbed powers of the composite structures. From the analysis, we note the following three important results. First, while the transmitted powers from forward and backward directions of the multilayer structure are identical (reciprocal feature), reflected (and absorbed) powers from forward and backward directions of the multilayer structure are different. This difference arises from reflection asymmetric nature of the bi-anisotropic MM slabs. Second, whereas the conventional material loss influences propagation characteristics aside resonance frequencies of bi-anisotropic MM slabs, bi-anisotropic MM loss worsens propagation properties of the multilayer structure at resonance frequencies of these slabs. Third, variations in (or determination of) electromagnetic properties of low-loss thin conventional materials in between two bi-anisotropic MM slabs can be realized at frequencies in which conventional materials demonstrate thickness-resonance effect.
AtıfScopus11WoS11OpenAlex13İncele - MakaleAçık Erişim2017Scopus SJRQ2Comparison of telomere length and insulin-like growth factor-binding protein 7 promoter methylation between breast cancer tissues and adjacent normal tissues in Turkish women
Kaya, Zehra; Akkiprik, Mustafa; Karabulut, Sevgi; Peker, Irem; Gullu Amuran, Gokce; Ozmen, Tolga; Gulluoglu, Bahadır M.; Kaya, Handan; Ozer, Ayse
Background: Both insulin-like growth factor-binding protein 7 (IGFBP7) and telomere length (TL) are associated with proliferation and senescence of human breast cancer. This study assessed the clinical significance of both TL and IGFBP7 methylation status in breast cancer tissues compared with adjacent normal tissues. We also investigated whether IGFBP7 methylation status could be affecting TL. Methods: Telomere length was measured by quantitative PCR to compare tumors with their adjacent normal tissues. The IGFBP7 promoter methylation status was evaluated by methylation-specific PCR and its expression levels were determined by western blotting. Results: Telomeres were shorter in tumor tissues compared to controls (P<.0001). The mean TL was higher in breast cancer with invasive ductal carcinoma (IDC; n=72; P=.014) compared with other histological type (n=29), and TL in IDC with HER2 negative (n=53; P=.017) was higher than TL in IDC with HER2 positive (n=19). However, telomeres were shortened in advanced stages and growing tumors. IGFBP7 methylation was observed in 90% of tumor tissues and 59% of controls (P=.0002). Its frequency was significantly higher in IDC compared with invasive mixed carcinoma (IMC; P=.002) and it was not correlated either with protein expression or the other clinicopathological parameters. Conclusion: These results suggest that IGFBP7 promoter methylation and shorter TL in tumor compared with adjacent tissues may be predictive biomarkers for breast cancer. Telomere maintenance may be indicative of IDC and IDC with HER2 (−) of breast cancer. Further studies with larger number of cases are necessary to verify this association.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2017Scopus SJRQ4The merrifield-simmons indices of 2-methyl alkanes and 1-methyl bicyclo [X.1.0] alkanes
Gültekin, Inci; Sahin, Bünyamin
In this paper the Merrifield-Simmons indices of the 2-methyl alkanes and the 1-methyl bicyclo [X.1.0] alkanes are obtained. After that, the Merrifield-Simmons index of the binary compositions of these molecules which are connected with a single carbon atom are obtained.
- MakaleYalnız künye2016Scopus SJRQ2Comparisons of surface and optical properties of the heavily carbon-doped GaN nanocrystalline films deposited by thermionic vacuum arc method
Pat, Suat; Özen, Soner; Şenay, Volkan; Korkmaz, Şadan
In this paper, heavily C-doped GaN samples were deposited on glass and PET substrates by the thermionic vacuum arc (TVA) method, for the first time. Microstructure, surface and optical properties of the carbon-doped GaN samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy, atomic force microscopy, and UV–Vis spectrophotometer. According to XRD pattern, fullerene (C60) structures were able to deposit in doped samples, for the first time. The fullerene structures were detected at heavily carbon-doped GaN. The obtained band gap changes of heavily carbon-doped GaN samples are determined. The band gap of CGaN on PET substrate decreased to a lower value, about 100 meV. The band gaps were shifted to the lowest wavelengths towards the edge of the UV region by heavily doped carbon. (002) and (004) peaks for GaN were also detected.
AtıfScopus6WoS5OpenAlex7İncele - MakaleYalnız künye2018Scopus SJRQ1Effect of ultrasound treatment on the properties of nano-emulsion films obtained from hazelnut meal protein and clove essential oil
Gul, Osman; Saricaoglu, Furkan Turker; Besir, Aysegul; Atalar, Ilyas; Yazici, Fehmi
Hazelnut meal protein (4% (w/v)) and clove essential oil (CEO) (3% (v/v)) were homogenized with ultrasound (US) at different times (2, 4 and 6 min) and amplitudes (50, 75 and 100%) to obtain nano-emulsion films. Film forming nano-emulsions (FFNs) were analyzed for average particle size (Dz) and zeta potential, and edible film characterization were evaluated depending on US treatment, as well as antibacterial and antioxidant activities. Dz values and zeta potential of FFNs decreased with increasing acoustic energy delivered to nano-emulsion system. Thickness and water solubility of films significantly decreased with increasing US treatment. Films became more transparent depending on US treatment probably due to particle size reduction. Tensile strength (TS) of films significantly increased with US treatment, while elongation at break (EAB) slightly increased. Microstructure of films became more homogeneous after US treatment and caused to lower water vapor permeability. Enrichment with CEO has given the films antibacterial activity against L. monocytogenes, B. subtilis, S. aureus, P. aeruginosa and E. coli, and antioxidant activity, and US application has improved these activities. US technology can be used to improve mechanical, barrier and antimicrobial properties of hazelnut meal protein based edible films enriched with CEO.
AtıfScopus158WoS141OpenAlex160İncele - MakaleAçık Erişim2018Scopus SJRQ2Production of (R)-1-(1,3-benzodioxol-5-yl)ethanol in high enantiomeric purity by Lactobacillus paracasei BD101
Şahin, Engin
Piperonyl ring is found in a number of naturally occurring compounds and possesses enormous biological activities. There are many studies in the literature with compounds containing a piperonyl ring, but there are very few studies on the synthesis of chiral piperonyl carbinol. The objective of this study was to determine the microbial reduction ability of bacterial strains and to reveal the effects of different physicochemical parameters on this reduction ability. A total of 15 bacterial isolates were screened for their ability to reduce 1-(benzo[d][1,3]dioxol-5-yl) ethanone 1 to its corresponding alcohol. Among these isolates Lactobacillus paracasei BD101 was found to be the most successful biocatalyst to reduce the ketone containing piperonyl ring to the corresponding alcohol. The reaction conditions were systematically optimized for the reducing agent L paracasei BD101, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale study was performed, and a total of 3.72 g of (R)-1-(1,3-benzodioxol-5-yl) ethanol in high enantiomeric form (>99% enantiomeric excess) was produced in a mild, cheap, and environment-friendly process. This study demonstrates that L paracasei BD101 can be used as a biocatalyst to obtain chiral carbinol with excellent yield and selectivity.
AtıfScopus43WoS42İncele - MakaleAçık Erişim2019Scopus SJRQ3An explicit characterization of spherical curves according to Bishop frame and an approximately solution
Balki Okullu, Pinar; Kocayigit, Huseyin; Agirman Aydin, Tuba
In this paper, spherical curves are studied by using Bishop frame. First, the differential equation characterizing the spherical curves is given. Then, we exhibit that the position vector of a curve which is lying on a sphere satisfies a third-order linear differential equation. Then we solve this linear differential equation by using Bernstein series solution method.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2018Investigation of learning outcomes in biology course curriculum in terms of mental skills
Toman, Ufuk
The purpose of this study is to examine the learning outcomes in the curriculum of Biology course in terms of reflective thinking skills. It is a documentary qualitative research. The target area of the study is the curriculum of the Biology course in secondary school level. Biology course curriculum of grades 9-12 was included in the research without any sampling in the research. Data collection method of the research is document analysis, and data analysis method is content and document analysis. We find that the vast majority of the learning outcomes of the units and subject areas in the biology course curriculum are in the practical reflection level. While the learning outcomes of the biology course curriculum are determined, mental skills need to be taken into account.
- BildiriAçık Erişim2017Scopus SJRQ3Evaluation of marble dust for soil stabilization
Yilmaz, F.; Yurdakul, M.
Usage of marble dust was investigated for soil stabilization in the scope of utilization of waste material. Geotechnical properties, such as compaction, Atterberg limits, unconfined compressive strength of the mixtures and changes of these properties with the marble dust ratio were determined. From the test results it is seen that marble dust increases the mechanical properties of soil and application of dust wastes for soil stabilization will be an efficient practice in terms of solid waste management.
AtıfScopus20WoS11OpenAlex23İncele - MakaleAçık Erişim2019Scopus SJRQ3Modeling of the impact of initial mold temperature, Al5Ti1B and Al10Sr additions on the critical fraction of solid in die casting of aluminum alloys using fuzzy expert system
Teke, Ç.; Çolak, M.; Taş, M.; İpek, M.
In the casting of liquid metal, the feeding stops when the mushy zone is clogged and does not allow the transfer of feeding liquid. The growing resistance of the solid dendrites against the fluidity of the feeding liquid is defined as the critical fraction of solid (CFS). CFS value varies depending on many factors such as alloy solidification range, initial mold temperature, and the grain size. Therefore, in many casting simulation applications, it is quite common to get inconsistent results due to insufficient information about the CFS. In this study, a fuzzy expert system (FES) model has been developed in order to determine the value of the CFS in the die casting process, based on the parameters of the alloy type, the initial mold temperature, Al5Ti1B addition and Al10Sr addition. In order to create the rule base for the FES model, 54 die casting experiments have been carried out. The CFS values obtained using the FES model has revealed that the developed model of the FES predicts the CFS value in a high performance.
AtıfScopus4WoS3OpenAlex6İncele - 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 - MakaleAçık Erişim2017Examining social and sociomathematical norms in different classroom microcultures: Mathematics teacher education perspective
Güven, N. Dilşad; Dede, Yüksel
Each classroom has its own microculture with its own norms that belong to this microculture. It is these norms that characterize every kind of activity and discussion in the classroom. What makes a mathematics classroom different from any other classroom is the nature of norms, rather than their existence or absence. This study aims to identify the social and sociomathematical norms that belong to different mathematics learning environments within this framework as a multiple-case study based on the qualitative design. The data has been collected through observations of two different classrooms in a mathematics teacher education program at a state university in Turkey. The constant comparative method was used for data analysis. This study, with prospective teachers as participants, identifies the social and sociomathematical norms that regulate the classroom microcultures. The findings show how norms with different qualities can be established and sustained in two different courses within the same teacher training program, and their possible effects on learning and teaching are discussed in the context of teacher education.
AtıfScopus21WoS11OpenAlex30İncele
