Koleksiyon/r/bayburt/10001

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Koleksiyondaki öğeler

  • MakaleYalnız künye2013Scopus SJRQ2
    Experimental and theoretical FTiR and FT-Raman spectroscopic analysis of 1-pyrenecarboxylic acid

    Karabacak, M.; Cinar, M.; Kurt, M.; Chinna Babu, P.; Sundaraganesan, N.

    The title molecule 1-pyrenecarboxylic acid (1PCA) has been characterized by FTiR, FT-Raman, NMR and UV-Vis spectral analyses. The molecular geometry, harmonic vibrational modes, the corresponding wavenumbers and iR intensities of 1PCA were calculated by DFT method with 6-311G(d, p) basis set. The assignments of the fundamentals were proposed on the basis of total energy distribution (TED) calculations. The calculated 13C and 1H NMR chemical shifts using gauge including atomic orbitals (GiAOs) approach are in good agreement with the observed chemical shifts. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. Using TD-DFT method, the electronic transitions have been compared with the experimental wavelengths. The molecular electrostatic potential map was used for prediction of possible hydrogen and oxygen bonding sites 1PCA molecule.

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  • BildiriYalnız künye2012Scopus SJRQ1
    The role of cogeneration systems in sustainability of energy

    Çakir, Uǧur; Çomakli, Kemal; Yüksel, Fikret

    Cogeneration system (CHP) is one of the ways to save the energy and use the energy efficiently. When compared to separate fossil-fired generation of heat and electricity, CHP may result in a consistent energy conservation (usually ranging from 10% to 30%) while the avoided CO 2 emissions are, as a first approximation, similar to the amount of energy saving. In terms of sustainability, one of the primary considerations is energy efficiency. Sustainable energy is considered as a kind of energy which is renewable and continuous, meaning that the use of such energy can potentially be kept up well into the future without causing harmful repercussions for future generations. In this study, environmental benefits and sustainability aspects of cogeneration systems and importance of those systems to the use of sustainable energy are underlined. To support this idea, first we have referred some scientific studies previously made on cogeneration systems and then we have used our own case study. The case study made on gas engined cogeneration system was applied for a hospital to show the sustainability aspects of cogeneration systems.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 12 · Sorumlu Üretim ve Tüketim
    • SDG 13 · İklim Eylemi
    AtıfScopus115WoS97OpenAlex135
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  • MakaleAçık Erişim2009Scopus SJRQ3
    Synthesis of two alnustone-like natural diarylheptanoids via 4+3 strategy

    Burmaoǧlu, Serdar; Çelik, Hülya; Göiksu, Süleyman; Maraş, Ahmet; Altundaş, Ramazan; Seçen, Hasan

    The first total synthesis of (4E,6E)-1,7-bis(3,4-dihydroxyphenyl)-hepta-4, 6-dien-3-one and an alternative synthesis of (4E,6E)-1,7-bis(4-hydroxyphenyl)- hepta-4,6-dien-3-one, two natural diarylheptanoids, mainly based on Claisen-Schmidt condensation were described. The crucial steps of the syntheses were the condensation of OH-protected 4-aryl-2-butanones with OH-protected 3-aryl-acrylaldehydes by the in situ enamination and then deprotection of OH groups to give the corresponding natural diarylheptanoids.

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  • MakaleYalnız künye2010Scopus SJRQ4
    Production of a novel pectin lyase from Bacillus pumilus (P9), Purification and characterisation and fruit juice application

    Nadaroǧlu, Hayrunnisa; Taşkin, Esen; Adigüzel, Ahmet; Güllüce, Medine; Demir, Nazan

    Extracellular pectin lyase (EC 4.2.2.10) was produced by Bacillus pumilus (P9) in solid state fermentation. Pectin lyase enzyme was purified 36.36 fold by using DEAE-cellulose anion exchange column chromatography and characterized. Molecular weight of the enzyme was determined as 25 kDa by using Sephadex G-100 gel filtration chromatography. Purification of enzyme was controlled by SDS-PAGE. The optimum pH and temperature of enzyme was determined as pH 6.0 and 60oC, respectively. Pectin lyase was mostly stable at 40°C. Its' activity deceased in 50% for 1h at 60°C and 40% for 4 h at 50°C. Vmax and KM were calculated respectively as 0.298 mg/mL and 132.6 mol/L*min. The presence of 10 mM concentration of Ca2+, Cu2+, Mn2+, Mg2+, Zn2+, Hg2+, Fe2+ and EDTA, L-cystein, ascorbic acid and -mercaptoethanol significantly enhanced the pectin lyase of the purified enzyme. The purified pectin lyase enzyme was used for getting fruits juices. It was determined that yields of fruits juices significantly improved when it was compared with control.

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  • MakaleYalnız künye2013Scopus SJRQ1
    Determination of aroma profiles of olive oils from Turkish olive cultivars

    Bayrak, Ali; Kıralan, Mustafa; Kara, Hasan Hüseyin

    This study analyzed volatile aromatic compounds present in the oils of Turkish olive cultivars. The cultivars Gemlik, AyvalIk, Memecik, Domat, Uslu, HalhalI, Kilis yaǧlIk, Nizip yaǧlIk, Haşebi and Karamani were harvested from important Turkish olive-growing locations, such as BalIkesir, Bursa, Manisa, AydIn, Muǧla, İzmir, Kilis, Mersin, Hatay and Gaziantep during the 2007-2008 and 2008-2009 growing seasons. Olive samples were collected in two harvest years, at almost the same maturity stage, and processed under the same conditions. Headspace solid-phase microextraction (HS-SPME) was used to analyze volatile aroma compounds in the olive oil samples. Forty-seven compounds were characterized and quantified using gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID). The most abundant identified compounds were trans-2-hexenal, hexanal and 3-methyl-1-butanol. The trans-2-hexenal, hexanal and 3-methyl-1-butanol contents of oil samples varied between 0.86-67.15, 3.93-61.82 and 0.48-84.74 %, respectively.

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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

    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
    AtıfOpenAlex2
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  • MakaleYalnız künye2017Scopus SJRQ2
    Optimum design of steel bridges including corrosion effect using TLBO

    Artar, Musa; Catar, Recep; Daloglu, Ayse T.

    This study presents optimum design of plane steel bridges considering corrosion effect by using teaching-learning based optimization (TLBO) method. Optimum solutions of three different bridge problems are linearly carried out including and excluding corrosion effect. The member cross sections are selected from a pre-specified list of 128 W profiles taken from American Institute of Steel Construction (AISC). A computer program is coded in MATLAB to carry out optimum design interacting with SAP2000 using OAPI (Open Application Programming Interface). The stress constraints are incorporated as indicated in AISC Allowable Stress Design (ASD) specifications and also displacement constraints are applied in optimum design. The results obtained from analysis show that the corrosion effect on steel profile surfaces causes a crucial increase on the minimum steel weight of bridges. Moreover, the results show that the method proposed is applicable and robust to reach the destination even for complex problems.

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  • MakaleAçık Erişim2015Scopus SJRQ3
    Primary school teacher candidates’ metaphorical perceptions related to multigrade classes concept; [Sınıf öğretmeni adaylarının birleştirilmiş sınıf kavramına ilişkin metaforik algıları]

    İlter, İlhan

    The purpose of the present study was to determine the teacher candidates’ perceptions related to ‘multigrade classes’ concept through metaphors. The study was conducted with the students who studied at their fourth (final) year in the Primary School Teaching Program, Faculty of Education at University of Bayburt in 2013-2014 academic year. The participants of the study were composed of 78 teacher candidates in total, 36 of them were girls and 42 of them were boys. The data collected in the research were obtained through an interview form in which there was an incomplete sentence like “The multigrade classes resemble…because…” In the process of collecting data, the teacher candidates were asked to write metaphors related to multigrade classes with the first justifications coming to their minds. In this study, phenomenology design, one of the qualitative research methods, was used and the research data were analyzed by means of the content analysis technique. According to the findings, the teacher candidates developed 60 different and valid metaphors in total about multigrade classes. The metaphors were classified under six different conceptual categories. These categories were classified in the form of multigrade classes as diversity in social-cognitive level and abilities, the process of challenging struggle, complementary-supportive service environment, source of life, family atmosphere and hierarchical order. It was found that the most preferred metaphors developed by the teacher candidates were extended family, family, flower garden, lush forest and Ashura.

    • SDG 4 · Nitelikli Eğitim
    AtıfScopus1OpenAlex7
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  • MakaleYalnız künye2016Scopus SJRQ1
    Characterisation of lactic acid bacteria from Turkish sourdough and determination of their exopolysaccharide (EPS) production characteristics

    Dertli, Enes; Mercan, Emin; Arici, Muhammet; Yilmaz, Mustafa Tahsin; Sağdiç, Osman

    A total of 249 Lactic Acid Bacteria (LAB) isolates were found in traditional Turkish wheat sourdoughs from Eastern Black Sea region of Turkey. Genotypic characterization of these isolates revealed the presence of 47 distinct LAB strains belonging to 11 different species: Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus curvatus, Lactobacillus rossiae, Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, Weissella paramesenteroides, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides and Weissella cibaria. The sourdough LAB microbiota differed depending on the sample origin and the collection period and heterofermentative LAB were dominant. The number of different species within a sourdough varied from 3 to 6 with the association of different hetero- and homofermentative LAB species. Exopolysaccharide (EPS) production characteristics of the isolates were determined and strain specific properties appeared to be important for the final EPS yields. Genes required for homopolysaccharide (gtf and lev) and heteropolysaccharide (epsA, epsB, p-gtf) production were PCR detected and several distribution patterns were observed. Results of this study confirmed the biodiversity of LAB species in traditional Turkish sourdough and highlighted the importance of EPS production in sourdough LAB strains.

    • SDG 2 · Açlığa Son
    AtıfScopus174WoS157OpenAlex168
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  • MakaleYalnız künye2017Scopus SJRQ1
    Characterization of functional properties of Enterococcus spp. isolated from Turkish white cheese

    İspirli, Hümeyra; Demirbaş, Fatmanur; Dertli, Enes

    Enterococcus species was isolated from Turkish white cheese and genotypic characterization of these isolates revealed the presence of 12 distinct strains belonging to 5 different species: Enterococcus faecium, E. faecalis, E. durans, E. gallinarum and E. italicus. All strains showed good survival ability under bile salt conditions. The antibiotic resistance of these strains was low but two strains showed high levels of resistance including resistance to vancomycin. PCR detection of virulence determinant in these isolates revealed that cheese isolate enterococci contained virulence genes common in gut and food originated enterococci and importantly two strains harboured cylB gene related to cytolysin metabolism. No complete hemolytic activity was observed for Enterococcus strains but partial hemolytic activity was observed 8 out of 12 strains. Additionally, all strains showed important levels of antimicrobial activity against food-borne pathogens and PCR screening of genes encoding enterocin A and B indicated the presence of enterocin B gene in all tested strains. The antimicrobial activities of the tested strains were lost after proteolytic enzyme treatments but no alteration was observed at different pHs and after heat treatments. In summary, this study reflected characteristics of Enterococcus strains presented in Turkish white cheese in terms of functional and safety perspectives.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus56WoS55OpenAlex68
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  • MakaleAçık Erişim2018Scopus SJRQ2
    Isolation and characterisation of lactic acid bacteria from traditional koumiss and kurut

    Ispirli, Hümeyra; Dertli, Enes

    Lactic acid bacteria (LAB) were isolated from traditional koumiss and kurut samples and identification of these isolates revealed the presence of Lactobacillus fermentum, Enterococcus faecalis, Enterococcus durans, and Lactobacillus helveticus species. L. fermentum and L. helveticus strains were further tested for different characteristics. All tested strains produced heteropolymeric exopolysaccharides (EPS) with the presence of glucose and galactose as sugar monomers whereas three strains produced fructan type EPS as homopolymeric EPS. Important levels of antibacterial and antifungal activities were observed in these strains. All tested strains were sensitive to the antibiotics tested except streptomycin. Half of the tested strains showed important levels of survival ability under mimicking gastrointestinal conditions.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus20WoS14OpenAlex22
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  • BildiriYalnız künye2017
    Effect of chemical dosage on color parameters of hydrophobic calcium carbonate obtained in aqueous solution

    Uçurum, M.

    Ultra-fine ground calcium carbonate is widely utilized as a performance mineral in rubber, plastics and paper industries. Both micronized calcium carbonate and a chemical (sodium oleate) treated calcium carbonate products, obtained in the aqueous solution, were used in the experiments. The color property is an important factor that affects the acceptability of the industrial mineral products. The current study describes the relationship between micronized calcium carbonate and coated calcium carbonate on the basis color parameters (L∗, a∗, b∗), whiteness index (WI), saturation index (SI), hue angle (H) and total color difference (ΔE). The results showed that the processing variables (chemical dosage) did not have a significant effect on the color parameters of hydrophobic calcium carbonate products.

  • MakaleAçık Erişim2015Scopus SJRQ2
    The investigation of prevalence and risk factors associated with cyber bullying and victimization; [Siber zorbalik ve maʇduriyetin yayginliʇinin ve risk faktörlerinin ̄ncelenmesi]

    Eroʇlu, Yüksel; Aktepe, Evrim; Akbaba, Sirri; Işik, Adem; Özkorumak, Evrim

    The aim of this study was to examine risk factors related to cyber bullying and victimization. The study was carried out with 160 adolescents applying to the Child/Adolescent Psychiatry Outpatient Clinic of the Faculty of Medicine of Süleyman Demirel University in Isparta, Turkey. Data was collected through using the Socio-Demographic Information Form, Internet Addiction Scale, and Cyber Victim and Bullying Scale. The results of the study showed that cyber bullying was related to gender, the risk of Internet addiction, the frequency of visiting Internet cafes, adolescents' perception of their mothers' Internet skills, the daily duration of visiting social networking sites, usage of the Internet predominantly to play online games, the monthly income of the family, and the mothers' educational status. Cyber victimization, on the other hand, was found to be related to the risk of Internet addiction, the frequency of visiting Internet cafes, adolescents' perception of their mothers' Internet skills, and usage of the Internet predominantly to play online games. The results of the study were discussed in the light of relevant literature.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    • SDG 5 · Toplumsal Cinsiyet Eşitliği
    • SDG 16 · Barış, Adalet ve Güçlü Kurumlar
    AtıfScopus19WoS24OpenAlex41
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  • MakaleAçık Erişim2017Scopus SJRQ2
    Zn/ZnSe thin films deposition by RF magnetron sputtering

    Yudar, H. Hakan; Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan

    In this paper, Zn/ZnSe thin films were deposited on glass substrates by RF magnetron sputtering system. XRD analyses were done. Zn and ZnSe phases were obtained. Miller indices of obtained Zn phases were detected in (320), (620) and (112) crystal formation. For the ZnSe phases, only one peak of (110)/(220) was observed. The surface morphology of the samples was investigated by an atomic force microscopy tools. It found that average roughness of the films was increased by raised RF power. The thin films around 80 % of high transmittance were measured. The band gap values were calculated as to be ~2.80 eV by the Cauchy model. The calculated refractive indices values were approximately 2.25 by a relation between the refractive index and the band gap.

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  • MakaleYalnız künye2018Scopus SJRQ2
    Investigation of the effect of RF energy on optical, morphological, chemical and antibacterial properties of PolyTerpenol thin films obtained by RF-PECVD technique

    Bayram, Ozkan; Simsek, Onder

    In this study, it was aimed to obtain PolyTerpenol thin films by radio frequency plasma enhanced chemical vapor deposition technique using Terpinen-4-ol essential oil, which is organic compounds. The surface morphology and chemical properties of polymer thin films were investigated by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy. AFM analyzes of PolyTerpenol thin films revealed that the thin films are homogeneous, smooth and nonporous. The optical properties of the thin films were determined using UV–Vis spectrophotometer. When optical band gaps of thin films were examined, it was found that this value varied from 3.83 to 3.20 eV. The extinction coefficients of the obtained thin films according to the increasing RF energy were calculated as 0.0011, 0.0060, 0.0085 and 0.0150, respectively, at a wavelength of 320 nm. In addition, antibacterial effects of these thin films against Escherichia Coli (E.Coli) bacteria were also investigated. The PolyTerpenol thin films were found to have high antibacterial activity against E. Coli bacteria.

    AtıfScopus8WoS8OpenAlex11
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  • MakaleAçık Erişim2015Scopus SJRQ3
    Some new records and one new species of the genus Lebertia Neuman (Acari: Hydrachnidia: Lebertiidae) from Turkey

    Esen, Yunus; Erman, Orhan

    In this study, water mites of the genus Lebertia Neuman, 1880 (Acari: Hydrachnidia) collected from Antalya, Artvin, Bingöl, Erzurum, Kahramanmaras, and Siirt provinces of Turkey are presented. In total, 12 species were determined. Of these, Lebertia (s. str.) marasensis sp. nov. is described as new to science, while L. (s. str.) rufipes Koenike, 1902; L. (Pilolebertia) longiseta Bader, 1955; L. (Pilolebertia) pilosa Maglio, 1924; L. (Mixolebertia) separata Lundblad, 1930; and L. (Brentalebertia) minutipalpis K. Viets, 1920 are new records for the Turkish fauna.

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  • MakaleAçık Erişim2017Scopus SJRQ1
    Delocalization and charge transfer studies of PERMENDUR49, KOVAR and Ti50Co50 alloys from relative K X-ray intensity ratios

    Uğurlu, Mine; Alım, Bünyamin; Han, İbrahim; Demir, Lütfü

    Kβ-to-Kα X-ray intensity ratios of Fe, Ni, Co, Ti, V in pure form and PERMENDUR49 (Fe49Co49V2), KOVAR (Fe54Ni29Co17) and Ti50Co50 alloys were calculated in order to determine valence-electron structure of the samples. The obtained experimental Kβ-to-Kα X-ray intensity ratios were found to be 0.1252 ± 0.0025, 0.1256 ± 0.0027, 0.1298 ± 0.0026, 0.1327 ± 0.0028, 0.1346 ± 0.0027 for pure Ti, V, Fe, Co and Ni, respectively. These values of present pure metals have increased with the increment in atomic number of these pure metals. Also, although the obtained these values for metal atoms in PERMENDUR49, Ti50Co50 and for Fe, Ni metal atoms in KOVAR approximately compatible with respect to results same pure metals, the obtained experimental Kβ-to-Kα X-ray intensity ratios for Co in KOVAR are significantly different from the appropriate values for pure Co metal. Then, the valence-electron populations of these alloys were calculated in order to answer as to why the characteristic properties of the studied alloys are distinct from each other. The valence-electron structures of these metals in pure form and alloys were determined by comparison of the calculated Kβ-to-Kα X-ray intensity ratios with the results of multi-configurations Dirac-Fock (MCDF) calculations to understand the charge-transfer and/or delocalization phenomena of these alloys. The experimental n3d values were found to be 3.2694, 4.7905, 7.7941, 7.9618, 8.500 for pure Ti, V, Fe, Co and Ni, respectively. The calculated 3d and 4s, 4p electron population values for Ti, V and Co in pure form have shown very little deviation from the appropriate values of Ti in Ti50Co50 and Co, V in PERMENDUR49. Also, the deviation for these values is greater for Fe, Ni, in KOVAR, Co in Ti50Co50, Fe in PERMENDUR49 with respect to the corresponding values of pure metals and the largest deviation for these values is observed for Co metal atoms in KOVAR alloy. We have also calculated the weighted average numbers of 3d and 4s, 4p electrons per one atom as well as the superposition of 3d and 4s, 4p electrons, as obtained from pure metal values. While the obtained superposition 3d electron numbers of present alloys exhibit a decreasing tendency as S3d(Ti50Co50) < S3d(PERMENDUR49) < S3d(KOVAR), the obtained weighted average 3d electron numbers of present alloys has opposite tendency (A3d(KOVAR) < A3d(PERMENDUR49) < A3d(Ti50Co50)). The analysis show that valance-electron population of elements in these alloys indicated differences with respect to the pure metal and each other. These differences can be related to type of alloy elements, concentration of alloy elements, charge transfer and/or delocalization phenomena between of individual metal atoms in alloys. Also, the obtained results show that there are alloying effect on valence-electron population due to charge transfer and/or delocalization phenomena.

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  • MakaleAçık Erişim2018Scopus SJRQ2
    Synthesis of Enantiomerically Enriched Drug Precursors by Lactobacillus paracasei BD87E6 as a Biocatalyst

    Öksüz, Selda; Şahin, Engin; Dertli, Enes

    Global sales of single enantiomeric drug products are growing at an alarming rate every year. A total of 7 bacterial strains were screened for their ability to reduce acetophenones to its corresponding alcohol. Among these strains Lactobacillus paracasei BD87E6 was found to be the most successful biocatalyst to reduce the ketones to the corresponding alcohols. The reaction conditions were systematically optimized for the reducing agent Lactobacillus paracasei BD87E6, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale asymmetric reduction of 3-methoxyacetophenone (1h) by Lactobacillus paracasei BD87E6 gave (R)-1-(3-methoxyphenyl)ethanol (2h) with 92% yield and 99% enantiomeric excess. Compound 2h could be used for the synthesis of (S)-rivastigmine which has a great potential for the treatment of Alzheimer's disease. This study demonstrates that Lactobacillus paracasei BD87E6 can be used as a biocatalyst to obtain chiral carbinol with excellent yield and selectivity. The whole cell catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that Lactobacillus paracasei BD87E6 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus16WoS14OpenAlex15
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  • BildiriYalnız künye2017
    Examination of absorption effects at the Compton to coherent scattering intensities X-rays using Fe-Ca and Fe-Ti binary compounds with WDXRF

    Boydaş, Elif; Boydaş, Mustafa Gökalp; Allm, Bünyamin

    Matrix absorption effects have been examined with scattered X-rays by using WDXRF system for Fe-Ca and Fe-Ti binary compounds. Fe as analyte and elements which some of them the K absorption edge just below the characteristic K X-ray energies of the analyte (Fe) as matrix have been chosen. Pure and binary with Fe ratio ranging from 10% to 90% samples were prepared with these elements. These samples have been analyzed in WDXRF system. At the end of measurement, the coherent and Compton scattering X-rays data of Rh Kα X-rays from these samples have been obtained. Matrix absorption effects have been examined by calculating coherent / Compton scattered X-rays intensity ratio.

    AtıfScopus3WoS2OpenAlex2
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  • MakaleYalnız künye2017Scopus SJRQ1
    Continuous and discontinuous contact problem of a functionally graded layer resting on a rigid foundation

    Adıyaman, Gökhan; Öner, Erdal; Birinci, Ahmet

    In this study, the continuous and discontinuous contact problem of a functionally graded (FG) layer resting on a rigid foundation is considered. The top of the FG layer is subjected to normal tractions over a finite segment. The graded layer is modeled as a non-homogenous medium with a constant Poissons’ ratio and exponentially varying shear modules and density. For continuous contact, the problem was solved analytically using plane elasticity and integral transform techniques. The critical load that causes first separation and contact pressures is investigated for various material properties and loadings. The problem reduced to a singular integral equation using plane elasticity and integral transform techniques in case of discontinuous contact. The obtained singular integral equation is solved numerically using Gauss–Jacobi integral formulation, and an iterative scheme is employed to obtain the correct separation distance. The separation distance and contact pressures between the FG layer and the foundation are analyzed for various material properties and loading. The results are shown in Tables and Figures. It is seen that decreasing stiffness and density at the top of the layer result in an increment in both critical load in case of continuous contact and separation distance in case of discontinuous contact.

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