Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(17)
- Şahin, Engin(8)
- Bayram, Ozkan(7)
- Esmer, Yusuf(7)
- Degirmenci, Yavuz(6)
- Yilmaz, Mustafa Tahsin(6)
- Dursunoğlu, İsmail(5)
- Göktaş, Bora(5)
- İspirli, Hümeyra(5)
- Şenay, Volkan(5)
- Bulut, Mehmet(4)
- Can, Zehra(4)
- Kaban, Güzin(4)
- Korkmaz, Özge(4)
- Pabuçcu, Hakan(4)
- Sagdic, Osman(4)
- Sefali, Abdurrahman(4)
- Serencam, Hüseyin(4)
- Simsek, Onder(4)
- Taylan, Osman(4)
- Ag, Aliriza(3)
- Bayraktar, Bülent(3)
- Bulut, Ayhan(3)
- Cuce, Erdem(3)
- Dayi, Faruk(3)
- Durmaz, Atakan(3)
- Gökçe, H. Süleyman(3)
- Küçük Demir, Betül(3)
- Mavi, Ahmet(3)
- Ucan, Izzet(3)
- Uçurum, Metin(3)
- Özen, Soner(3)
- Öztürk, Mesut(3)
- Abdioglu, M.(2)
- Acar, Adalet(2)
- Agirman Aydin, Tuba(2)
- Akay, Ebru Çağlayan(2)
- Akkan, Yaşar(2)
- Akkoyunlu, Ebubekir(2)
- Akkuş, Ömer(2)
Yayınlar
- MakaleAçık Erişim2019Scopus SJRQ1High temperature resistance of boron active belite cement mortars containing fly ash
Gökçe, H.Süleyman
Boron allowing stability of reactive belite phase in clinker production enhances neutron shielding capability of cement. In the study, neutron attenuation factor of boron active belite cements at various fly ash introduction was theoretically revealed by comparing with an alternative low heat cement (portland composite cement). High temperature resistance of the cements with and without fly ash introduction was determined on standard mortar prisms at elevated temperatures up to 900 °C with regard to compressive strength and flexural strength. Neutron shielding performance of boron active belite cement was found almost 25 times higher than Portland composite cement. Fly ash introduction significantly reduced the neutron attenuation factor of boron active belite cement. High temperature resistance of boron active belite cement mortar was found lower than that of Portland composite cement mortar at 700 °C at later curing time. 10% fly ash introduction improved the high temperature performance of boron active belite cement mortar exposed to 900 °C. Residual compressive strength values of the mortars containing fly ash were between 16% and 28% after exposing 900 °C.
AtıfScopus39WoS36OpenAlex39
İncele - MakaleAçık Erişim2019Scopus SJRQ2Resource- and content-aware, scalable stitching framework for remote sensing images
Eken, Süleyman; Mert, Ümit; Koşunalp, Selahattin; Sayar, Ahmet
This paper proposes a new approach to solving the scalability problem in stitching and registration of satellite images. The image stitching process is mostly utilized to capture an image of an entire object, whose parts fall in separate but overlapping mosaics. Due to their high resolutions and huge sizes, the stitching of satellite mosaic images is time- and resource-consuming process. The work presented in this paper proposes a resource- and content-aware, scalable stitching technique. The main idea is based on measuring and assessing the available hardware resources of the machine, on which stitching process runs, and scaling the resolution of the images accordingly. Moreover, preprocessing is not needed, and the adjustment is performed dynamically at run time. The effectiveness of the proposed technique was assessed by partially registering overlapping satellite mosaic images of the island of Cyprus and Lake Van. The scalability tests are performed on varying numbers and sizes of the overlapping LandSat-8 satellite images.
AtıfScopus8WoS6OpenAlex8İncele - MakaleAçık Erişim2019Scopus SJRQ2Fruit and seed macro- and micromorphologies of the genus Matthiola (Brassicaceae) in turkey and their taxonomic value
Kaya, Ayla; Ünal, Murat; Sefali, Abdurrahman; Martin, Esra
Macro- and micromorphological features of fruit and seeds belonging to 12 taxa genera of Matthiola W.T.Aiton were studied via stereomicroscope and scanning electron microscope. In macromorphological studies, the following variables were investigated: The shape, size, and color of fruit and seeds; the length of fruiting pedicel; the structure of the median vein; stigma (horns); and trichome properties and density in fruit. In micromorphological studies, the presence or absence of seed wings, seed coat pattern in disc and wing, and epidermal cell shape in disc and wing were determined. According to our findings, all characters of fruit and seeds are extremely variable and can be used as criteria to distinguish species of the genus.
AtıfScopus5WoS4TR Dizin1
İncele - MakaleAçık Erişim2019Scopus SJRQ3A Differential Evolution Algorithm-Based Traffic Control Model for Signalized Intersections
Cakici, Ziya; Murat, Yetis Sazi
Sustainable management of traffic flows at signalized intersections is an important issue in terms of traffic engineering. The minimization of lost time, emission, fuel consumption, etc., can be achieved by optimization-based intersection management. In this study, a new traffic signal control model is developed for the management of three-leg signalized intersections. In the proposed model, signal timing and signal phasing are optimized simultaneously using Differential Evolution (DE) algorithm which is one of the population-based metaheuristic algorithms. The effectiveness of the model is tested on sample traffic scenarios with VISSIM simulation software considering average vehicle delay performance criteria. Results show that the proposed approach may reduce the average vehicle delay between the rates of 28%-42% and 3%-38% comparing to the optimum fixed-time signal control and vehicle-actuated signal control for tested scenarios, respectively.
AtıfScopus39WoS37OpenAlex39İncele - MakaleAçık Erişim2019Scopus SJRQ1Characterization of a 4,6‑α‑glucanotransferase from Lactobacillus reuteri E81 and production of malto-oligosaccharides with immune-modulatory roles
İspirli, Hümeyra; Şimşek, Ömer; Skory, Christopher; Sağdıç, Osman; Dertli, Enes
A wide number of Lactic Acid Bacteria (LAB) species produce α-glucans with their ability to synthesize glucansucrases (GS) which use sucrose as substrate for the glucan production. Recently another group of enzymes in LAB gained special interest for their ability to produce α-glucans targeting the substrates containing α1-4-linkages and synthesizing new (α1-6) or (α1-3)–linkages as α‑glucanotransferases. In this study, a putative 4,6‑α‑glucanotransferase (GTFB) from sourdough isolate Lactobacillus reuteri E81 was identified and expressed in Escherichia coli. The biochemical characterization of the GTFB-E81 confirmed its function as it cleaved the α1-4-linkages in different substrates and produced new gluco-oligomers/polymers containing α1-6 linkages together with the α1-4-linkages detected by NMR analysis. GTFB-E81 produced malto-oligosaccharides targeting maltose and maltoheptaose as substrates with up to DP 8 detected by TLC and ESI-MS/MS analysis. The functional roles of these malto-oligosaccharides were determined by testing their immune-modulatory functions in HT29 cells and they triggered the production of anti-inflammatory 1L-4 and pro-inflammatory IL-12 cytokines.
AtıfScopus43WoS40OpenAlex42
İncele - MakaleAçık Erişim2019Scopus SJRQ2Physicochemical characterisation of an α-glucan from Lactobacillus reuteri E81 as a potential exopolysaccharide suitable for food applications
İspirli, Hümeyra; Sagdic, Osman; Yılmaz, Mustafa Tahsin; Dertli, Enes
Lactobacillus reuteri strain (E81) is an alpha glucan producer from traditional sourdough and the physicochemical characteristics of this glucan was determined in this study. The HPLC analysis confirmed the presence of glucose as the only sugar monomer in the repeating structure of this exopolysaccharide (EPS). The functional groups within the glucan structure was detected by FTIR analysis. The scanning electron microscopy (SEM) analysis demonstrated the web-like branched structure of the glucan. Morphological characterisation of the glucan E81 by atomic force microscopy (AFM) analysis showed clear roundness lumps and chains. Importantly, thermal characteristics of glucan E81 determined by thermogram analysis (TGA) and differential scanning calorimeter (DSC) analysis revealed that glucan E81 has a melting point of 290 °C making it promising to be used in thermal processed foods including sourdough bread.
AtıfScopus77WoS71OpenAlex77İncele - Derleme MakaleAçık Erişim2019Scopus SJRQ2Thermoelectric Coolers (TECs): From Theory to Practice
Guclu, Tamer; Cuce, Erdem
Thermoelectric coolers (TECs) are solid state units, which provide reliable energy conversion with no noise or vibration. They are also lightweight and do not include any moving parts. The current coefficient of performance (COP) range of TECs has shown a trend of improvement, and TECs have a wide range of usage areas. Within the scope of this research, TECs are comprehensively evaluated in terms of several aspects such as type, material, design, modelling, thermal performance, potential applications, economic and environmental issues. It can be achieved through the results that the COP of TECs is highly dependent on the temperature difference between hot and cold side (ΔT), and maximum COP is obtained when ΔT is close to zero. It is also observed that COP can be enhanced by more than 55% when the hot side is thermally regulated by phase change materials (PCMs) or integrated with a water cooling unit.
AtıfScopus69WoS61OpenAlex76İncele - MakaleAçık Erişim2019Scopus SJRQ2Characterization of an interesting selenium-dependent glutathione peroxidase (Se-GPx) protecting cells against environmental stress: The Camelus dromedarius erythrocytes Se-GPx
Chafik, Abdelbasset; Essamadi, Abdelkhalid; Çelik, Safinur Yildirim; Solak, Kübra; Mavi, Ahmet
Camel lives most of its life under high environmental stress in the desert. Glutathione peroxidase plays a key role in protecting cells against oxidative stress. For the first time, selenium-dependent glutathione peroxidase (Se-GPx) was purified from camel erythrocytes, biochemically characterized, and some of its properties were studied. The enzyme was purified using ethanol-chloroform treatment, acetone precipitation and ion exchange chromatography. A purification fold of 33.72 with 0.19% yield were obtained. The native molecular weight of the enzyme was estimated to be about 69 kDa. On SDS-PAGE, the enzyme was composed of two different subunits with a molecular weight of approximately 53 and 21 kDa. An optimum temperature of 47 °C and an optimum pH of 7.2 were found. The activation energy was 41.71 kJ/mol. This enzyme was inhibited by thiol reagents, D,L-Dithiothreitol and β-Mercaptoethanol, and was sensitive to bivalent cations. The enzyme had a general specificity toward hydroperoxides, and high specificity for reduced glutathione. The purified enzyme contained 3.06 mol of selenium per mol of protein. The Km and Vmax values for hydrogen peroxide and reduced glutathione were 0.72 and 1.58 mM, and 25.33 and 31.03 U/mg, respectively. The biochemical properties of camel Se-GPx were different comparing to those of mammalian species. Lower molecular weight, heterodimeric structure, higher optimum temperature, relatively lower optimum pH, lower content of selenium and higher affinity for hydrogen peroxide at low reduced glutathione concentration, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert.
AtıfScopus11WoS10OpenAlex10İncele - MakaleAçık Erişim2019Scopus SJRQ2Effects of artificial weathering on the surface properties of ultraviolet varnish applied to lemonwood (Citrus limon (L.) Burm.)
Ayata, Ümit
Ultraviolet varnishes are widely used for production processes in the parquet industry. A large number of chemicals are used in this sector, and each one has different characteristics. In this study, the effects of accelerated aging of ultraviolet varnish (3 and 5 coats) when applied to lemonwood (Citrus limon (L.) Burm.) (grown in Mezitli, Mersin, Turkey) were investigated. The ultraviolet varnish coated samples were subjected to aging processes (144 h, 288 h, and 432 h) by using UV-A 340 nm lamps. Color (L*, a*, b*, and ΔE*) parameters, glossiness (perpendicular (⊥) and parallel (//) at 20°, 60°, and 85°), and surface adhesion strength via the pull-off method for ultraviolet varnish coated samples were quantified before and after weathering. According to the results, the varnish type, aging period, and interaction between all studied variables, i.e. L*, a*, b* color parameters, glossiness (perpendicular (⊥) and parallel (//) at 20°, 60°, and 85°), and adhesion strength were found to alter the surface properties. As a result, the lemon tree can be used in the production of an ultraviolet parquet system.
AtıfScopus16WoS12OpenAlex17İncele - MakaleAçık Erişim2019Scopus SJRQ3Genotypic identification of lactic acid bacteria in pastirma produced with different curing processes; [Farklı kürleme İşlemleri İle üretilen pastırmada laktik asit bakterilerinin genotipik İdentifikasyonu]
Çınar, Kübra; Fettahoğlu, Kübra; Kaban, Güzin
The lactic acid bacteria isolated from pastirma, produced under controlled conditions using two different curing temperatures (4°C or 10°C) and two different curing agents (150 mg/kg sodium nitrite or 300 mg/kg potassium nitrate), were subjected to genotypic (16S rRNA sequecing) identification. According to the identification results, 68 of 87 isolates (78.16%) was identified as Pediococcus pentosaceus. This species was followed by P. acidilactici (14.94%), Lactobacillus sakei (4.60%) and L. plantarum (2.30%), respectively. P. pentosaceus was dominant species in all curing applications (4°C/nitrate or nitrite or 10°C/nitrate or nitrite). Another species determined in all groups was P. acidilactici. While L. plantarum was only isolated from samples produced with nitrate (4°C or 10°C), L. sakei was isolated from samples produced with nitrite (4°C or 10°C). The effect of the curing agent on the biodiversity of lactic acid bacteria in pastirma was more effective than the curing temperature.
AtıfScopus3WoS3OpenAlex2İncele - MakaleAçık Erişim2019Phenolic composition and antioxidant properties of anzer honey from black sea region of Turkey; [Türkiye'nin Karadeniz Bölgesinden Anzer Balinin Fenolik Bilesimi ve Antioksidan Özellikleri]
Malkoç, Meltem; Çakir, Hilal; Kara, Yakup; Can, Zehra; Kolayli, Sevgi
Anzer honey is produced on the Anzer plateau, known for its rich flora, in the Eastern Black Sea region of Turkey. It is well known across the world, and is believed to be of high medical value. This study is the first detailed research in which the polyphenolic profiles responsible for the bioactive properties of Anzer honey was determined, melissopalynological analysis was performed, and in which total phenolic contents (TPC), total flavonoid contents (TFC), and total antioxidant activities were identified. The ferric (III) reducing antioxidant power (FRAP) assay and 1,1-diphenyl-2- picrylhydrasil (DPPH) free radical scavenging test were used to determine antioxidant activity. The total mean phenolic content of Anzer honey was 26.92 GAE/100 g, and the total flavonoid content was 2.79 mgQE/100g. Anzer honeys' mean FRAP and DPPH values were 110.11 μmoLTrolox/100g and 49,12 mg/mL, respectively. The phenolic acids and flavonoids of Anzer honey were determined using highperformance liquid chromatography (HPLC). Of the 19 standard compounds used in the analysis, pinocembrin, hesperidin, chrysin, protocatechuic acid, p-coumaric acid, catechin, caffeic acid phenyl ester (CAPE), p-OH benzoic acid, and caffeic acid as major compounds, while myricetin, luteolin, rutin, resveratrol, epicatechin, t-cinnamic acid, ferulic acid, and gallic acid were identified as minor compounds. Daidzein and syringic acid were not detected. Based on these findings, Anzer is a flower honey noteworthy for the rich variety of its polyphenols.
AtıfScopus22OpenAlex26TR Dizin8İncele - MakaleAçık Erişim2019Scopus SJRQ3A study concerning berger type deformed sasaki metric on the tangent bundle
Altunbas, Murat; Simsek, Ramazan; Gezer, Aydın
Let TM be the tangent bundle over an almost anti-paraHermitian manifold endowed with Berger type deformed Sasaki metric gBS. In this paper,first, we obtain the Levi-Civita connection of this metric and study geodesics on TM. Secondly, we construct some almost anti-paraHermitian structures on TM and search conditions for these structures to be anti-paraKähler and quasi-anti-paraKähler. Finally, we present certain Riemannian curvature properties of (TM, gBS).
AtıfScopus36OpenAlex21İncele - MakaleAçık Erişim2019Scopus SJRQ3Investigation of Stress Corrosion Cracking Behaviour of Mg-Al-Zn Alloys in Different pH Environments by SSRT Method
Catar, Recep; Altun, Hikmet
In this study, stress corrosion behaviors of AZ31, AZ61 and AZ91 Mg alloys which contain different amounts of Al were investigated under acidic, basic and neutral environments having chloride ions using Slow Strain Rate Test (SSRT) method. Stress corrosion indexes (ISCC), ultimate tensile strength (UTS) and elongation of AZ31, AZ61, and AZ91 Mg alloys were determined and compared. Slow strain rate test showed that three Mg alloys in basic environments were the least stress corrosion susceptible, while the most stress corrosion susceptible occurred in acidic environments. Also, it has been shown that the stress corrosion indexes of AZ91 Mg alloys are less than AZ31 and AZ61 Mg alloys in all environments. UTS and elongation of AZ61 Mg alloys were higher than those of AZ31 and AZ91 in all media. The fracture of surface images also examined in the scanning electron microscope (SEM) and both intergranular stress corrosion cracking (IGSCC) and transgranular stress corrosion cracking (TGSCC) were observed in all three alloys.
AtıfScopus16WoS13OpenAlex14İncele - MakaleYalnız künye2019Scopus SJRQ1The effectiveness of the monetary transmission mechanism channel in Turkey
Okur, Fatih; Akkuş, Ömer; Durmaz, Atakan
This study investigates on which channels the monetary transmission mechanism works effectively. In this context, quarterly data for the period 2005-2017 is used for Turkey and the variables used to determine the efficiency of the monetary transmission mechanism are analyzed by the VAR method. The obtained results indicate that the loans and reserves have a more effective role on the inflation as a channel of the monetary transmission mechanism. According to the long run results, while the exchange rate and reserves channel have a negative effect on the real GDP, it is revealed that loans have a positive effect on the real GDP in the long run stabilization.
AtıfScopus3İncele - MakaleAçık Erişim2019Scopus SJRQ1Electrospraying method for fabrication of essential oil loaded-chitosan nanoparticle delivery systems characterized by molecular, thermal, morphological and antifungal properties
Yilmaz, Mustafa Tahsin; Yilmaz, Azime; Akman, Perihan Kubra; Bozkurt, Fatih; Dertli, Enes; Basahel, Abdulrahman; Al-Sasi, Basil; Taylan, Osman; Sagdic, Osman
Fabrication of essential oil loaded-chitosan nanoparticles using electrospraying technique appears to be a novel strategy to develop thermally stable nanoparticles possessing higher encapsulation efficiency and particle stability. This study aims to fabricate chitosan nanoparticles (CNPs) loaded with Origanum vulgare essential oil (OEO, Origanum vulgare L.) at different proportions (OEO/CH proportions of 0:1, 0.0625:1, 0.125:1, 0.25:1 and 0.5:1 mL/g) using electrospraying technique. The CNPs were characterized in term of their particle size and stability (dynamic light scattering), encapsulation efficiency (spectrophotometry), and molecular (Fourier transform infrared spectroscopy), thermal (differential scanning calorimetry/thermogravimetric analysis), morphological (scanning electron microscopy) and antifungal (agar dilution method) and fungistatic activity properties. The average particle sizes of the CNPs ranged between 290 and 483 nm with a spherical morphology. Positively charged surface characteristics were observed to increase with the increment of OEO concentration in CNPs. The encapsulation efficiency values were determined in the range of 70.1 and 79.6%. The molecular and thermal analyses exposed very decent encapsulation of OEO into thermally stable chitosan nanoparticles. Morphological analysis verified the spherical shapes of these nanoparticles. Above all, the antifungal effectiveness of OEO against the Alternaria alternata AY1 could be significantly (p < 0.05) increased by its encapsulation into chitosan nanoparticles fabricated by the electrospraying technique. Consequently, it can be stated that the electrospraying technique developed is able to fabricate thermally stable nanoparticles owning higher encapsulation efficiency and particle stability. The results and findings suggest that the electrospraying technique would be a promising method to fabricate chitosan-based nanoparticles as an antimicrobial agent to control their release in a prolonged preservative effect in cosmetic, pharmaceutical and food applications for adjustable dosage forms. Industrial relevance: The fungal agents such as Alternaria alternata cause great damages on post-harvest fresh fruits and vegetables, thus leading to a great economical lose. Therefore, a great variety of methods in struggling with disease have been previously proposed. Nowadays, the most effective leading methods to struggle against plant diseases are those applied with synthetic fungicides to minimize such lose in post-harvest fruit and vegetables. However, intensive and unconscious use of the fungicides leads the pathogens to develop resistance against these agents as well as to accumulation of chemical residues in soil, water and air and finally to formation of carcinogenic effects on human health. Nowadays, a great effort is being exerted to develop novel biodegradable and natural antimicrobial agents for struggling fungal spoilage in postharvest products. Essential oils are among the most widely used natural struggling methods. Essential oils obtained from plants have been extensively used since they are natural antimicrobial agents. However, they cannot be effectively used in spite of their extensive applications. Recently, some researches in the field of nanotechnology have demonstrated that the effectiveness of active substances could be increased by using some techniques. In this respect, we aimed at developing essential-oil-loaded-chitosan-nanoparticle delivery systems using an electrospraying deposition system to prevent fungal colonization on food and plant materials. By increasing antifungal effectiveness of essential oils by their encapsulation into nanoparticles, it will be possible to decrease the levels of regularly applied dose and reflect the obtained outcomes to the food and agriculture industry. This study is the first example of production of essential oil loaded nanoparticles using the electrospraying-hydrodynamic process and showed that encapsulation of oregano essential oil into chitosan based nanoparticles (CNPs) by using the electrospraying deposition technique considerably increased the antifungal effectiveness of the Origanum vulgare essential oil. Our results highlight the potential use of the chitosan nanoparticles (CNPs) loaded with different amounts of Origanum vulgare in food and agriculture industry as an effective fungicidal material against Alternaria alternata, suggesting that the CNPs can be promising tools to compete with synthetic fungicide counterparts and limit use of synthetic ones for struggling of food and plant pathogens. Therefore, 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. In this respect, the CNPs would find a great industrial application area in the food and agriculture industry which seek natural preservatives due to the recent health concerns.
AtıfScopus119WoS101OpenAlex118İncele - MakaleAçık Erişim2019Scopus SJRQ3A functional bleeding test apparatus for concrete
Gökçe, H. Süleyman; Andiç-Çakır, Özge
Bleeding is one important indicator that is related to the physical and mechanical properties of fresh and hardened concrete. Standards generally prefer methodologies that are similar to one another to measure the bleeding of fresh concrete. The preferred test apparatus used in the standards is troublesome because it requires a manual test procedure and repeated measurements until final setting of the fresh concrete. The functional bleeding test apparatus presented in this study will ease test performance and eliminate the faults caused by the test procedure and the experimenter.
AtıfScopus2WoS1OpenAlex3İncele - MakaleAçık Erişim2019Scopus SJRQ1Characterization of chemical, molecular, thermal and rheological properties of medlar pectin extracted at optimum conditions as determined by Box-Behnken and ANFIS models
Al-Amoudi, Rami H.; Taylan, Osman; Kutlu, Gozde; Can, Asli Muslu; Sagdic, Osman; Dertli, Enes; Yilmaz, Mustafa Tahsin
In this work, response surface methodology and adaptive neuro-fuzzy inference system approaches were used to predict and model effect of extraction conditions of pectin from medlar fruit (Mespilus germanica L.). The pectin extracted at optimized conditions (89 °C, 4.83 h and 4.2 pH) could be classified as high methoxyl pectin. Sugar composition analysis showed that pectin was mainly composed of D-galacturonic acid, L-arabinose, L-rhamnose, D-galactose and D-glucose. Fourier Transform Infrared Spectroscopy, RAMAN and nuclear magnetic resonance spectra confirmed molecular structure, revealing presence of D-galacturonic acid backbone. X-ray diffraction patterns revealed an amorphous structure. Differential scanning calorimetry showed endothermic (123 °C) and exothermic peaks (192 °C). Thermogravimetric analysis revealed three decomposition regions, 50–225 °C, 225–400 °C and 400–600 °C. Steady and dynamic shear analyses revealed that pectin had a pseudo-plastic behavior with storage (G′) and loss (G″) modulus increasing with increment in frequency, indicating viscoelastic structure more predominantly elastic than viscous.
AtıfScopus89WoS79OpenAlex83İncele - MakaleAçık Erişim2019Scopus SJRQ2A study of gamma attenuation property of UHMWPE/Bi 2 O 3 nanocomposites
Abdalsalam, Alyaa H.; Sayyed, M.I.; Ali Hussein, Thulfiqar; Şakar, Erdem; Mhareb, M.H.A.; Ceviz Şakar, Betul; Alim, Bünyamin; Kaky, Kawa M.
In this study, nanocomposite material made of ultra-high molecular weight and bismuth oxide was developed to be used for protection from nuclear radiation. The traditional hot-pressing technique was used for preparing composite samples. The concentrations of Bi 2 O 3 were selected to be 0.5, 1.0, 1.5, 2.0 wt%. In order to study the changes in surface morphology, we examined all samples by scanning electron microscopic (SEM). We evaluated the semi-quantitative of all elements used to fabricate these samples using EDX. Additionally, all samples including pure Bi 2 O 3 has been examined with X-ray diffraction (XRD). Besides that, Raman spectroscopy of all synthesized polymer matrix was measured to explore the different molecular groups. Also, the photon attenuation ability for the present samples was measured experimentally at eight energies varying from 30.8 keV to 383.9 keV using 133 Ba radioactive point source.
AtıfScopus68WoS64OpenAlex70İncele - MakaleYalnız künye2019Scopus SJRQ2Investigation on seismic isolation retrofit of a historical masonry structure
Artar, Musa; Çoban, Keziban; Yurdakul, Muhammet; Can, Ömer; Yilmaz, Fatih; Yildiz, Mehmet B.
In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.
AtıfScopus12WoS12OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ3Biodiversity and characterization of gram-positive, catalase-positive cocci isolated from pastırma produced under different curing processes
Fettahoğlu, Kübra; Çinar, Kübra; Kaya, Mükerrem; Kaban, Güzin
The aim of this study was to determine the effects of different curing temperatures (4 °C or 10 °C) and agents (KNO3 or NaNO2) on microbiological and physicochemical properties of pastırma and diversity of gram-positive, catalase-positive cocci (GCC+) and also to investigate some technological properties of the strains. Four different groups of pastırma were produced applying different curing temperatures and agents. After production, GCC+ isolated from pastırma were subjected to phenotypic and genotypic (16S rRNA sequencing) identification. Genotypically characterized strains were evaluated for their technological properties. In all groups, aw and pH were observed to be under 0.90 and over 5.5, respectively. In genotypic identification, 45 isolates were identified as Staphylococcus vitulinus, while other isolates identified were S. equorum (n = 15), S. saprophyticus (n = 15), and S. xylosus (n = 12). All of the strains could grow at different salt concentrations (8% and 15%) and temperatures (4 °C, 10 °C, and 37 °C). Four strains of S. saprophyticus showed strong lipolytic activity while nine strains of S. vitulinus had strong proteolytic activity. This study showed that different curing temperatures and agents are particularly effective on the microflora in pastırma; however, these factors do not cause a high diversity in GCC+ in terms of species.
AtıfScopus6WoS6OpenAlex7TR Dizin2İncele