Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleYalnız künye2011Scopus SJRQ1
    The investigating high school students' learning styles with respect to the different variables: A sample from Turkey

    Metin, Mustafa; Yilmaz, Gul Kaleli; Birisci, Salih; Coskun, Kerem

    The aim of this study is to investigate high school students' learning styles in terms of gender, grade level, type of school, graduation type of mother and father variables. The study was carried out at spring semester of 2010 with 660 high school students who were chosen as a sample from the cities of Artvin and Trabzon, in Turkey. "Kolb Learning Style Inventory" was used as a data collection tool. The inventory was used to determinate the students' learning styles as divergent, assimilator, convergent, and accommodator and the information sheet for demographic factors such as gender, grade level, school type, education of mother and father was used to collect information from students. The data were analyzed by using frequency, percent value, mean scores, standard deviation, independent samples t-test and one-way ANOVA. The results show that the dominant learning style among the students is accommodator and it is followed by divergent learning style. There was not significantly difference between students' learning style and gender except for "Active Experimentation (AE) and AE-RO", grade level "except for Concrete Experience (CE)", school type, education of mother "expert for Reflective Observation (RO)" and education of father.

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  • MakaleYalnız künye2011Scopus SJRQ1
    Waste utilization: The removal of textile dye (Bomaplex Red CR-L) from aqueous solution on sludge waste from electrocoagulation as adsorbent

    Yilmaz, Alper Erdem; Boncukcuoglu, Recep; Kocakerim, Muhtar; Karakas, Ibrahim Hakki

    The potential of removing Bomaplex Red CR-L dye from electro coagulation sludge has been investigated for different Bomaplex Red CR-L concentrations with varying adsorbent amount, temperature, pH and stirrer speed. Removal of Bomaplex Red CR-L is found to be high at lower pH values. The maximum adsorption of the dye has been achieved in aqueous solutions using 0.5g of calcinated sludge from electro coagulation at a pH of 2.0 within 20min. The Langmuir and Freundlich isotherm models were tested and it was found that the Langmuir equation was fitted better than the Freundlich equation. Maximum adsorption capacity (q m) was calculated as 192.31mg g -1 at 333K. In addition, the adsorption data obtained at various temperatures were successfully applied to pseudo first-order, pseudo second-order and intraparticle diffusion models. The rates of adsorption were found to conform to pseudo second-order kinetics with good correlation (R 2≥0.9997). This study showed that calcinated the sludge from electrocoagulation has a highly adsorbent capacity.

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  • MakaleAçık Erişim2011Scopus SJRQ3
    A new species of Raphignathus Dugés (Acari, Raphignathidae) and newly discovered male of R. Fani Doǧan and Ayyildiz from Turkey

    Dönel, Güldem; Doǧan, Salih

    A new mite species, Raphignathus kelkitensis n. sp. and a newly discovered male of Raphignathus fani Doǧan and Ayyildiz from Turkey are described and illustrated.

    AtıfScopus10WoS9OpenAlex8
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  • MakaleAçık Erişim2011Scopus SJRQ3
    The effects of silica fume and fly ash on the scaling resistance and flexural strength of pavement concretes

    Yener, Engin; Hinislioǧlu, Sinan

    The purpose of this study is to investigate the effects of Silica Fume (SF) and Fly Ash (FA) additives on the frost salt scaling resistance and flexural strength properties of pavement concrete. An attempt is also made to attain a more durable and higher strength concrete by a suitable combination of Ordinary Portland Cement (OPC), SF and FA. SF and FA are used as cement replacement in proportions of 0, 5, 10% and 0, 5, 10, 15% by weight respectively. Flexural strength is tested after 7, 28 and 91 days of the lime saturated water curing period. The experimental results indicate that using FA only decreases while SF only slightly increases 28-days flexural strength. On the other hand, using SF and FA together shows relatively more strength gain. Among all those tested, maximum 28 days flexural strength of 4.53 MPa is obtained for the mix proportions of 85% OPC + 10% FA and 5% SF. SF significantly decreases the amount of liquid absorption by capillary suction and has a significant effect on the scaling resistance. In addition, all the ternary mixtures showes better scaling resistance than the control mixture with 100% OPC.

    AtıfScopus13WoS23
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  • BildiriYalnız künye2011
    A Novel approach for modeling mechanical behavior of porous media

    Altan, Burhanettin S.; Mollamahmutoglu, Murat

    A multi-scale novel homogenization technique is introduced to model mechanical behavior of open-cell porous media. The proposed method consists of primarily four components. The first component is based on two assumptions. First, a random porous structure can be approximated by superimposing regular grids that are interacting with each other at "junction" points. The second component consists of replacing each grid by an equivalent continuum. The forces at the junction points are also replaced by interacting body forces. The third component is to represent the equivalent media by single medium by expressing the "average stresses" in the elastic mixture in terms of the "average displacement" It is discussed how to extract the information about the geometrical and mechanical properties of the grids by comparing the analytical and experimental data for the dispersion of waves propagating in porous medium.

  • MakaleYalnız künye2011Scopus SJRQ2
    Engineering properties of medium-to-fine sands injected with microfine cement grout

    Mollamahmutoglu, Murat; Yilmaz, Yuksel

    This article investigates the penetrability of microfine cement suspensions prepared with Rheocem 900 with and without superplasticizer additive into various graded fine-to-medium sands into which chemical grout permeation is only possible. Initially, the basic rheological properties such as viscosity, setting time, and stability of microfine cement suspensions are studied. In addition, penetration performance of the suspensions into various graded fine to medium sand specimens under different grouting pressures is examined. Finally, the strength and permeability characteristics of various graded fine-to-medium sand specimens permeated with microfine cement suspensions are studied. It is found that a superplasticizer additive greatly increases the grouting performance of microfine cement and reduces the grouting pressure. Moreover, it is seen that the unconfined compressive strengths of sand specimens permeated with a cement grout without additive are slightly less than those of sand specimens permeated with cement grout and superplasticizer additive. Further-more, permeability tests on specimens permeated with cement grouts with or without a superplasticizer reveals that all specimens are impermeable (k<1 10 7 m=s).

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  • BildiriYayıncıda açık erişim2011
    Identifying the secondary school students' misconceptions about functions

    Cansiz, Şükrü; Küçük, Betül; Lşleyen, Tevfik; Akcamete, G; Uzunboylu, H; Oulmu, S; Karahoca, A; Babadoan, C; Ozdamli, F; Kanbul, S

    It is very important to identify and correct the mistakes that students make about mathematical concepts. The purpose of this study is to detect the secondary school students' misconceptions about functions in the 2009-2010 academic year. Research data was collected 61 students, included 9 th,10 th and 11 th grade students selected randomly, in Erzincan (2009-2010) academic year. Data collection tools consist of knowledge test and interviews. Frequency tables and percentages were used by analyzing students' explanations as answers to questions on the function information test. Pearson correlation was chosen to state the meaningful difference among the questions, if there is any, on the Function information test also included four different categories. Student, being believed to be in error, were interviewed with the help of data obtained from Function information test. As a result of the interview, it is most commonly observed that students make mistakes to understand whether a graphic is a function graphic or not, and about the demonstration of the table and function especially on the function information test.

    • SDG 4 · Nitelikli Eğitim
    AtıfScopus6WoS3OpenAlex12
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  • BildiriAçık Erişim2011Scopus SJRQ2
    Site-response effects on RC buildings isolated by triple concave friction pendulum bearings

    Ates, Sevket; Yurdakul, Muhammet

    The main object of this study is to evaluate the seismic response effects on a reinforced concrete building isolated by triple concave friction pendulum (TCFP) bearings. The site-response effects arise from the difference in the local soil conditions at the support points of the buildings. The local soil conditions are, therefore, considered as soft, medium and firm; separately. The results on the responses of the isolated building are compared with those of the non-isolated. The building model used in the time history analysis, which is a two-dimensional and eight-storey reinforced concrete building with and without the seismic isolation bearings and/or the local soil conditions, is composed of two-dimensional moment resisting frames for superstructure and of plane elements featuring plane-stress for substructure. The TCFP bearings for isolating the building are modelled as of a series arrangement of the three single concave friction pendulum (SCFP) bearings. In order to investigate the efficiency of both the seismic isolation bearings and the site-response effects on the buildings, the time history analyses are elaborately conducted. It is noted that the site-response effects are important for the isolated building constructed on soft, medium or firm type local foundation soil. The results of the analysis demonstrate that the siteresponse has significant effects on the response values of the structure-seismic isolation-foundation soil system.

    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    AtıfScopus9OpenAlex7
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  • MakaleYalnız künye2011Scopus SJRQ2
    The stigmaeid mites (Acari: Stigmaeidae) of kelkit valley (Turkey)

    Dönel, Güldem; Doǧan, Salih

    The stigmaeid mites collected from Kelkit Valley in Turkey are investigated. Nine new species, Cheylostigmaeus urhani sp. nov., Eustigmaeus varius sp. nov., Ledermuelleriopsis indiscretus sp. nov., Stigmaeus additicius sp. nov., S. angustus sp. nov., S. ayyildizi sp. nov., S. furcatus sp. nov., S. kelkitensis sp. nov. and Prostigmaeus integrius sp. nov., are described and illustrated. The following four stigmaeid species are new records for the Turkish fauna: Cheylostigmaeus salinus Evans, Eustigmaeus lacuna (Summers), Stigmaeus glabrisetus Summers and S. solidus Kuznetsov. Some known stigmaeid mites are recorded from new localities. This is the first record of the genus Prostigmaeus Kuznetsov in Turkey. Keys to Kelkit Valley genera and species of Stigmaeidae are included.

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  • MakaleAçık Erişim2011Scopus SJRQ3
    Purification and characterization of a pectin lyase produced by Geobacillus stearothermophilus Ah22 and its application in fruit juice production

    Demir, Nazan; Nadaroglu, Hayrunnisa; Tasgin, Esen; Adiguzel, Ahmet; Gulluce, Medine

    Extracellular pectin lyase (PL) (EC 4.2.2.10) was produced by Geobacillus stearothermophilus Ah22 in solid state fermentation. The PL enzyme was purified 40.8-fold by DEAE-cellulose anion exchange column chromatography and characterized. The molecular weight of the enzyme was determined as 36 kDa by Sephadex G-100 gel filtration chromatography. Purification of the enzymewas verified by SDS-PAGE. The optimumpHand temperature of the enzyme were determined as pH 6.0 and 60°C, respectively. The PL was mostly stable at 40°C. Its activity deceased by 50% after 2 h at 60°C and by 60% after 6 h at 50°C. The V max and K m were calculated as 0.47 mg/mL and 355.3 μmol/L•min, respectively. The presence of 10 mM Ca 2+, Cu 2+, Mn 2+, Mg 2+, Zn 2+, Hg 2+, Fe 2+ and EDTA, L-cysteine and ascorbic acid significantly enhanced enzyme activity. The purified PL enzyme was used in the production of fruit juices; yields of fruits juice improved significantly compared with controls.

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  • MakaleYalnız künye2011Scopus SJRQ1
    Azathia crown ethers carrying pyrene pendant as receptor molecules for metal sensor systems

    Ocak, Ümmühan; Ocak, Miraç; Parlayan, Semanur; Başoǧlu, Aysel; Çaǧlar, Yasemin; Bahadr, Zekeriyya

    A series of crown ethers carrying a pyrene group with nitrogensulfur donor atoms, that differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 1-bromomethylpyrene. The influence of metal cations such as Mn 2+, Fe2+, Fe3+, Co2+, Ni 2+, Cu2+, Zn2+, Cd2+, Hg 2+, Pb2+ and Al3+ on the spectroscopic properties of the ligands was investigated in acetonitriledichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+. The results of spectrophotometric titration experiments disclosed the complexation compositions and complex stability constants of the novel ligands with Fe 2+, Zn2+, Cu2+, Pb2+ and Hg 2+ cations. The monoazatetrathia crown ether showed good sensitivity for Cu2+ with linearity in the range 5.0×10-72. 5×10-6 M and detection limit of 1.6×10-8 M.

    AtıfScopus9WoS9OpenAlex10
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  • BildiriYayıncıda açık erişim2011
    Investigation of university students' attitude toward the use of powerpoint according to some variables

    Kahraman, Sakip; Çevik, Ceren; Kodan, Hülya; Karahoca, A; Kanbul, S

    In this study it is aimed to investigate whether university students' attitudes toward the use of PowerPoint as a supporting teaching tool in the lectures change according to variables such as gender, academic units attended. For this purpose, the sample consisted of total 653 students who enrolled, Faculty of Education (N=287), Faculty of Engineering (N=125), School of Economics and Administrative Sciences (N=92) and Vocational School (N=149) in Bayburt University. Data was collected using "attitude toward the use of PowerPoint" scale. Additionally, students' opinions of the use of PowerPoint as a supporting teaching tool was collected from their responses to a questions form developed by researchers, then written documents analyzed to reveal their opinions with respect to the use of PowerPoint. The data obtained was statistically analyzed (ANOVA). It was found that there is no any statistically meaningful difference in the participants' attitude toward the use of PowerPoint in respect to gender, but there was significant difference in the participants' attitude toward the use of PowerPoint according to academic units attended. Recently, the findings were discussed in terms of the use of PowerPoint as a supporting tool in the lectures and its importance.

    • SDG 4 · Nitelikli Eğitim
    • SDG 5 · Toplumsal Cinsiyet Eşitliği
    AtıfScopus11WoS14OpenAlex25
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  • BildiriAçık Erişim2011
    A study on developing an attitude scale towards multi-grade classrooms for elementary school teachers

    Coskun, Kerem; Metin, Mustafa; Bülbül, Kenan; Yilmaz, Gül Kaleli; Akcamete, G; Uzunboylu, H; Oulmu, S; Karahoca, A; Babadoan, C; Ozdamli, F

    The aim of this study is to develop an attitude scale towards multi-grade classrooms (AMC) for elementary school teachers who work in the Multi-grade Classrooms. The research was carried out with the total 215 elementary school teachers in Tokat and Samsun provinces in Turkey. The study carried out in five stages that are literature review, creating item pool, expert opinions, administer of scale and computing the reliability and validity. The five point rating scale consisted of 50 items was developed. The draft scale obtained has been applied to the total 205 elementary school teachers and as a result of factor analysis; the number of items in draft scale was reduced to 43. The Cronbach-Alpha internal integrity coefficient of the final version of the scale was found to be 0.81 after factor analysis was carried out. The scale has been ready to be used.

    • SDG 4 · Nitelikli Eğitim
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