Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleYalnız künye2011Scopus SJRQ1
    Modeling of triple concave friction pendulum bearings for seismic isolation of buildings

    Yurdakul, Muhammet; Ates, Sevket

    Seismic isolated building structures are examined in this study. The triple concave friction pendulum (TCFP) is used as a seismic isolation system which is easy to be manufactured and enduring more than traditional seismic isolation systems. In the TCFP, take advantage of weight which pendulum carrying and it's geometry in order to obtain desirable result of seismic isolation systems. These systems offer advantage to buildings which subject to severe earthquake. This is result of damping force of earthquake by means of their internal constructions, which consists of multiple surfaces. As the combinations of surfaces upon which sliding is occurring change, the stiffness and effective friction change accordingly. Additionally, the mentioned the TCFP is modeled as of a series arrangement of the three single concave friction pendulum (SCFP) bearings. A two dimensional- and eight- story of a building with and without isolation system are used in the time history analysis in order to investigate of the effectiveness of the seismic isolation systems on the buildings. Results are compared with each other to emphasize efficiency of the TCFP as a seismic isolation device against the other friction type isolation system like single and double concave surfaces. The values of the acceleration, floor displacement and isolator displacement obtained from the results by using different types of the isolation bearings are compared each other. As a result, the findings show that the TCFP bearings are more effective devices for isolation of the buildings against severe earthquakes.

    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    AtıfScopus14OpenAlex12
    Scopusİncele
  • MakaleAçık Erişim2011Scopus SJRQ2
    A new eyeless mite species of the genus Eustigmaeus Berlese (Acari: Stigmaeidae) from Turkey; [Türkiye'den Eustigmaeus Berlese (Acari: Stigmaeidae) cinsine ait gözsüz yeni bir akar türü]

    Doǧan, Salih; Dönel, Güldem; Özçelik, Sezgin

    A new eyeless mite species of the genus Eustigmaeus from Turkey, Eustigmaeus anophthalmus, is described and illustrated.

    AtıfScopus27WoS27OpenAlex28
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2011Scopus SJRQ2
    Determination of protein and gluten quality-related parameters of wheat flour using near-infrared reflectance spectroscopy (NIRS); [Yakın Kızılötesi Spektroskopisi (NIRS) kullanarak buǧday unlarının protein ve glutenle ilgili kalite parametrelerinin belirlenmesi]

    Başlar, Mehmet; Ertugay, Mustafa Fatih

    Wet chemistry analyses done for quality control purposes in wheat and flour processing are time-consuming. Near-infrared spectroscopy (NIRS) as an alternative technology to conventional methods allows us to obtain results in a few seconds. In this study, NIRS was used in the development of calibration models for protein, wet and dry gluten contents and Zeleny sedimentation of flours from the grinding of 120 varieties of bread wheat collected from different regions of Turkey. Therefore, spectra in the range of 1100 to 2500 nm of the flours were acquired by scanning with the NIRSystems 6500 monochromator. Multiple linear regression (MLR) and partial least squares (PLS) regression were applied to the spectral data in log 1/R, and first derivative and second derivative of log 1/R formats. Reasonable results were obtained for protein, wet and dry gluten contents, and Zeleny sedimentation with r = 0.985, 0.976, 0.953, and 0.924, respectively.

    • SDG 2 · Açlığa Son
    AtıfScopus41WoS38OpenAlex52
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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; Hinislioğlu, 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.

    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    AtıfScopus9OpenAlex25
    Scopusİncele
  • MakaleAçık Erişim2011Scopus SJRQ2
    Airy's functions in nonlocal elasticity

    Altan, Burhanettin S.

    Nanostructured devices and materials, such as carbon nanotubes, Atomic Force Microscope, MEMS, etc. attract increasing attention in the scientific world. It has been realized that the classical elasticity is not capable to capture the mechanical behavior of them precisely. There is a wide consensus among the scientists that nonlocal elasticity is more capable than the classical counterpart to model the mechanical behavior of nanostructured materials and devices. In this paper a method which is useful for solving problems in nonlocal is introduced. Airy's stress functions for plane stress problems in nonlocal elasticity are studied. The nonlocal constitutive equations in integral form are discussed and a method is suggested to invert the constitutive equation which allows expressing strains in terms of stresses. A qualitative discussion is given on this inversion process. For the nonlocality kernel of exponential form, the differential equation for Airy's functions in nonlocal elasticity is obtained by introducing the strains into the compatibility condition. Appropriate polynomial forms for the Airy's function are considered and are applied to solve beam bending problems. The solutions are compared with their classical counterparts. The results are given in a series of figures and tables and are discussed in detail. This paper is concluded by indicating the implications of the presented study in nanomechanics and nanotechnology.

    AtıfScopus1OpenAlex1
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  • MakaleYalnız künye2011Scopus SJRQ1
    Synthesis of sterically constrained tricyclic pyrrolidinyl alcohol ligands for the enantioselective ethylation of aryl aldehydes: Assessment of the influence of ring strain and N-alkyl chain length on asymmetric induction

    Sahin, Engin; Kilic, Hamdullah

    A series of chiral sterically constrained tricyclic pyrrolidinyl alcohol ligands were synthesized from the appropriate amino acids, and a comparative study of the activity and selectivity of the ligands for the enantioselective ethylation of aromatic aldehydes was carried out. The results obtained were compared with those previously reported for related monocyclic analogues; it was found that the bicyclo[2.2.2]octane backbone fused to pyrrolidine and the groups attached to the carbinol centre, as well as the chain length of the β-amino alcohol, had a marked effect on the enantioselectivity. The enantioselective addition of dialkylzincs to aryl aldehydes in the presence of ligands with diethyl substituents on the carbinol carbon afforded (R)-sec-alcohols in up to 99% enantiomeric excess (ee).

    AtıfScopus5WoS5OpenAlex7
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  • MakaleYalnız künye2011Scopus SJRQ1
    A Taguchi approach for optimization of design parameters in a tube with coiled wire inserts

    Gunes, Sibel; Manay, Eyuphan; Senyigit, Ercan; Ozceyhan, Veysel

    This study presents the determination of the optimum values of the design parameters in a tube with equilateral triangular cross-sectioned coiled wire inserts. The effects of the design parameters such as the ratio of the distance between the coiled wire and test tube wall to tube diameter (s/D), pitch ratio (P/D), ratio of the side length of equilateral triangle to tube diameter (a/D) and Reynolds number (Re) on heat transfer and pressure drop were investigated by using Taguchi method. The Nusselt number and friction factor were considered as performance parameters. An L9(34) orthogonal array was chosen as experimental plan. The goal of this study is to reach maximum heat transfer (i.e. Nusselt number) and minimum pressure drop (i.e. friction factor). First of all, each goal was optimized, separately. Then, all the goals were optimized together, considering the priority of the goals. Contribution ratios for each parameter on the heat transfer and pressure drop were determined. Consequently, the optimum results were found to be s/D = 0.0357, P/D = 1, a/D = 0.0714 and Re = 19800.

    AtıfScopus115WoS100OpenAlex113
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  • MakaleYalnız künye2011Scopus SJRQ1
    A new energy saving for the determination of mixing temperature in hot mix asphalts

    Yener, Engin; Hinislioglu, Sinan

    The equi-viscous temperature range of asphalt has long been used in establishing the mixing temperature for mix designs and field production of hot mix asphalt (HMA). However, this method considers only binder viscosity to determine the mixing temperatures of the aggregate and asphalt. It is well known that depending on the gradation of aggregate and the type of plant and the mixing time. The appropriate mixing temperature for the proper coating may be lower than that of the viscosity based method. The excessive temperature causes the possible performance problems related to the hardening of the asphalt binder and increases the energy consumption, the gas emissions and fumes. In this study, a new method for the determination of asphalt-aggregate mixing temperature which considers the mixture properties was introduced to asphalt industry. The mixing temperatures of different nine mixtures were determined by both conventional and the proposed method. The effects of the nominal maximum aggregate size (NMAS), crushed coarse aggregate ratio (CCAR), the type of gradation, and the grade of binder on the mixing temperature were evaluated with an experimental study. Results show that decreasing NMAS, CCAR and increasing the grade of binder decreased the mixing temperature which is needed for proper coating. In addition, results showed that as going away from restricted zone of the Superpave gradation, the needed temperature to coat the aggregates decreased. The proposed method resulted in lower temperatures comparing to the conventional method on an average of 13°C. This means a possible energy saving of 14.3 x 10 9 kcal or 1362000 kg of crude oil in a year in Turkey. As a result, the new method is recommended due to not only the saving in energy but also decreasing the gas emissions and fume, and possible performance benefits.

    AtıfScopus16
    Scopusİncele
  • MakaleAçık Erişim2011Scopus SJRQ1
    Effect of photosonication treatment on inactivation of total and coliform bacteria in milk

    Şengül, Mustafa; Erkaya, Tuba; Başlar, Mehmet; Ertugay, M. Fatih

    The combined effect of simultaneously applied acoustic energy and ultraviolet irradiation (UV-C), named photosonication, on the population reduction of total and coliform bacteria in raw milk was investigated. Photosonication was carried out at 100% (120 μm; 240 W) amplitude of ultrasound accompanied by UV light of 13.2 W cm-2 while sonication was carried out at 100% amplitude without UV light. An ultrasonic processor (400 W and 24 kHz with a 22 mm diameter probe) and 3 ultraviolet lamps (4400 μW cm-2 per lamp) were used. The exposure time was 15 min for all treatment, and samples were taken after 0, 3, 6, 9, 12 and 15 min. Thermal treatment (at 65 °C for 30 min) achieved a 3.29 log and 5.31 log-reduction for total and coliform bacteria, respectively. However, the reduction achieved was 4.79 log cfu mL-1 and 5.31 log cfu mL-1 for total and coliform bacteria, respectively, in photosonication while 1.31 log cfu mL-1 and 4.01 log cfu mL-1 for total and coliform bacteria, respectively in sonication. During photosonication, UV light contributed to an increase of lethality.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    • SDG 6 · Temiz Su ve Sanitasyon
    AtıfScopus33WoS32OpenAlex39
    ScopusWeb of Scienceİncele
  • 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.

    AtıfScopus13
    Scopusİncele
  • 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.

    AtıfScopus62WoS55
    ScopusWeb of Scienceİncele
  • 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
    ScopusWeb of Scienceİncele
  • 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
    ScopusWeb of Scienceİncele
  • 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).

    AtıfScopus73WoS65
    ScopusWeb of Scienceİncele
  • 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.

    AtıfScopus50OpenAlex54
    Scopusİncele
  • 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.

    AtıfScopus35WoS28OpenAlex28
    ScopusWeb of Scienceİncele
  • 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
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2010
    A Solution Approach to Assembly Line Balancing Problem With Task Related Constraints and an Application At An Enterprise

    İşlier, A. Attila; Altuntas, Serkan

    Occasionally certain tasks in an assembly line balancing problem are required to be kept together due to some specific reasons. These tasks are attained to the same work stations. Such problems are called as ‘Assembly Line Balancing Problem with Task Related Constraints (ALBTRC)’. Certain situations like awkward product construction, simultaneous operations or specific requirements leading to zoning and positional constraints like utilization of common resources as tools, jigs and fixtures are implemented thanks to these supplementary constraints. Additionally, materials handling and tooling costs, distances, set-up and lead times are also reduced. Literature on ALBTRC seems quite rare compared to Classical Line Balancing papers, although ALBTRC is one of the common real life balancing problems. This study aimed to develop and implement a novel line balancing method for a manufacturing concern where known methods are impractical to employ due to some specific positional constraints. ‘Largest Candidate Method’ known as a simple but effective tool is modified for this purpose first. Then a thorough ‘method and time study’ is conducted to get the necessary data to utilize that method. As a result, more efficient alternatives are generated and presented to decision maker

    AtıfTR Dizin3
    TR Dizinİncele
  • MakaleYalnız künye2010
    Authority: Divine Or Qur'anic?

    Şentürk, Mustafa; Elelvânî, Tâhâ C

    The Author who examines divine authority in his article, differentiated between the authority in the Qur'an to the authority asserted by contemporary Islamic movements. According to him, contemporary Islamists have been colored by attempts to counter Western concepts of authority, government and legitimacy by taking the concept of Qur'anic authority out of context and without considering the Qur'an's structural integrity, universality and final significance. According to the author, the authority of the Qur'an is like human authority, because it functions through a human reading and application.

  • MakaleYalnız künye2010
    Determination of economical-social satisfaction, trust and loyalty relations of channel members: A research conducted over dealers of white goods located in Eastern Anatolia

    Yilmaz, Mustafa Kemal; Erciş, Aysel; Unal, Sevtap

    Channel members enabling the delivery of goods and services to target markets play a significant role in terms of capturing marketing goals of manufacturer businesses and in terms of providing goods and services of buyers they require. But, intensification of competition and by means of new outcomes pertaining to marketing assimilation, enterprises discovered the dominant advantages of better relations with intermediaries and long term cooperation. The present study aiming to determine economical-social satisfaction, trust and loyalty relations of channel members have been conducted on white goods dealers located in Eastern Anatolia. At the end of the study, economical satisfaction level and understanding of Manufacturer Company&amp;#8217;s friendly treatment further to determination of dealer&amp;#8217;s loyalty to manufacturer firm have been found playing a direct role and social satisfaction levels and trustworthiness of manufacturer firm have been found playing an indirect role.