Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(62)
- Merdan, Mehmet(58)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(43)
- Ashyralyyev, Charyyar(38)
- Karsli, Orhan(33)
- Öztürk, Serkan(32)
- Araz, Onur(31)
- Demir, Selim(29)
- Kulakaç, Nurşen(29)
- Dokuz, Abdurrahman(28)
- Arslan, Mehmet(27)
- Baltacı, Cemalettin(27)
- Maden, Nafiz(27)
- Sipahi, Ferkan(27)
- Topal, Fevzi(27)
- Turan, Ibrahim(27)
- Kandemir, Raif(25)
- Kurt, Kemal(24)
- Ozturk, Samet(24)
- Peker, Iskender(24)
- Vural, Alaaddin(24)
- Reis, Hatice Catal(23)
- Yücel, Cem(23)
- Aydin, Faruk(22)
- Baltaci, Cemalettin(22)
- Gücer, Mehmet Ali(22)
- Günen, Mehmet Akif(22)
- Kankal, Murat(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(20)
- Kurnaz, Muammer(19)
- Tuncer, Metin(19)
- Yolcu, Halil(19)
- Çelik, Necati(19)
- Ürkek, Bayram(19)
- Şan, Murat(19)
- Aliyazicioglu, Yuksel(18)
Yayınlar
- MakaleAçık Erişim2011The relationship between the peroxisome proliferator-activated receptor gamma 2 gene polymorphism, lipids and adipokines in patients with major depression; [Majör depresyonlu hastalarda peroksizom çoǧaltici-aktive edici reseptör gama 2 gen polimorfizmi, lipidler ve adipokinlerle ilişkisi]
Aliyazicioglu, Rezzan; Deǧer, Orhan; Vanizor Kural, Birgül; Hocaoǧlu, Çiçek; Çolak, Meltem; Balaban Yücesan, Fulya
Objective: Peroxisome proliferator-activated receptor gamma (PPARγ), lipids, lipoproteins, and adipokines have recently been shown to be associated with psychiatric diseases. Our major aim is to investigate the contribution of the PPARγ gene polymorphism, adipokines, lipids, and lipoproteins to the development of major depression. Material and Methods: The frequency of Pro12Ala in exon 2 and C478T in exon 6 of the PPARγ gene, lipids and adipokines in major depression (n = 78) and control subjects (n= 64) were analyzed. Genotypes of PPARy gene polymorphisms were examined. Serum leptin, adiponectin, and resistin were studied by enzyme-linked immunosorbent assay (ELISA). Serum apo A1, apo B, and Lp(a) levels were determined by immunonephelometry. Serum total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol levels were analyzed by enzymatic methods. Results: The genotypes of exon 2 and exon 6 distribution did not differ between the control subjects and patients with major depression. Frequencies of genotypes of Pro12Ala, and Ala12Ala in exon 2 in overweight and obese patients with major depression were higher than those of overweight and obese controls. C478T polymorphism was highest in overweight and obese patients with major depression. Pro12Ala and Ala12Ala genotypes in exon 2 of PPARγ gene in patients were found to be associated with triglyceride and HDL-cholesterol. There were significant differences regarding glucose, total cholesterol, LDL-cholesterol, apo B, Lp(a), adiponectin and resistin levels between patient and control subjects. Conclusion: PPARγ exon gene polymorphisms, alterations in lipid profile and adipokines may be associated with the development of major depression.
- MakaleYalnız künye2011Kinetics and isotherm analysis of basic dyes adsorption onto almond shell (Prunus dulcis) as a low cost adsorbent
Duran, Celal; Ozdes, Duygu; Gundogdu, Ali; Senturk, Hasan Basri
The feasibility of using an agricultural byproduct, almond shell (Prunus dulcis), as an adsorbent in removal of basic dyes, namely, methylene blue (MB), methyl violet (MV), and toluidine blue O (TB), were evaluated in a batch adsorption process. The adsorption characteristics of MB, MV, and TB onto almond shell (AS) were investigated with respect to the changes in initial pH of dye solutions, contact time, initial dye concentration, and temperature. The dye adsorption equilibria were rapidly attained after 30 min of contact time. The adsorption kinetics were analyzed using pseudofirst-order, pseudosecond-order, Elovich, and intraparticle diffusion models and the adsorption data were well described by the pseudosecond-order model. The equilibrium adsorption data were interpreted in terms of the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherm models. The monolayer adsorption capacity of AS was found to be 51.02 mg·g-1 for MB, 76.34 mg·g-1 for MV, and 72.99 mg·g-1 for TB by using the Langmuir model equation. The thermodynamic parameters proved that the present adsorption process was feasible, spontaneous and endothermic in nature in the temperature range of (5 to 40) °C.
- MakaleYalnız künye2011Operating regimes of the government: Accounting and accountability changes in the sultan süleyman waqf of the ottoman empire (the 1826 experience)
Yayla, Hilmi Erdoǧan
Following Foucauldian accounting research, this article analyzes the relationship between accounting changes and "governmentality" practices by examining the accounting and accountability changes in the Sultan Süleyman Waqf of the Ottoman Empire in accordance with the restructuring regulations of Evkaf-i{dotless} Humayun Nezareti, established in 1826 for the purpose of the centralization of waqfs. It is argued that accounting was a technique in the hands of the Ottoman government that facilitated the translation of imperial objectives of the 1826 regulation into practice, the formation of the waqf in tune with government's desired outcomes, and the construction of governable bodies, as well as providing a controlling device from a distance (Latour, 1987; Miller & Rose, 1990). This article also aims to show how accounting and accountability techniques were used to make people calculable in the organizational spaces of an Islamic state standing in history (Foucault, 1991a). Thus, this article adds to the Foucauldian understanding of the role and functioning of accounting by examining a non-western oriented setting.
- MakaleYalnız künye2011Late Triassic subduction-related ultramafic-mafic magmatism in the Amasya region (eastern Pontides, N. Turkey): Implications for the ophiolite conundrum in Eastern Mediterranean
Eyuboglu, Yener; Santosh, M.; Bektas, Osman; Chung, Sun-Lin
The eastern Pontides orogenic belt of northeastern Turkey offers critical clues on convergent margin tectonics associated with the late Mesozoic-early Cenozoic geodynamic evolution of the eastern Mediterranean region. Here we report the geology, petrology, geochemistry, Nd-Sr-Pb isotopes and U-Pb zircon ages from a ultramafic-mafic complex in Aksalur which forms part of a series of Alaskan-type ultramafic-mafic bodies in the Amasya region located at the south-western corner of the eastern Pontides orogenic belt. These ultramafic-mafic intrusions occur as minor (30-300m in diameter), scattered, roughly circular bodies within the low-grade metamorphic rocks of the Tokat metamorphic massif. Petrographic studies characterise the rock types as gabbro and wehrlite, with the latter showing typical cumulate texture and mainly comprising serpentinized olivine, clinopyroxene, hornblende, mica and opaque minerals. The gabbroic rocks are characterized by relatively high initial ratios of 143Nd/144Nd (0.512618-0.512633) and low initial ratios of 87Sr/86Sr (0.70420-0.70435). Their initial Pb isotope ratios range from 17.306 to 17.771. The gabbros and cumulate wehrlites display geochemical distribution patterns analogous to the Alaskan-type intrusions that were derived from a subduction-related, high-alumina, hydrous basaltic parental magma in a convergent plate setting. LA-ICPMS analyses of zircons separated from the gabbros show high Th/U ratios (1.35-5.26) typical of magmatic origin. The U-Pb isotopic data define a weighted mean 206Pb/238U age of 203.3±4.9Ma. Detailed evaluation of the magma tectonics suggests that the Alaskan-type Aksalur ultramafic-mafic intrusions were accumulated in magma chamber(s) located at relatively shallow crustal levels. Two distinct magmatic pulses are identified: the first phase produced the gabbroic intrusions and the second phase was characterized by numerous small-scale werhlitic cumulate intrusions. In contrast to the previous models which assigned a mid-oceanic ridge-derived ophiolite affinity for ultramafic-mafic complexes in the eastern Pontides orogenic belt, our study reveals that these intrusions were derived from subduction-related high-alumina hydrous basaltic magmas transferred into the overlying relatively thin continental crust along deep-seated fractures.
- MakaleYalnız künye2011Cultivar characterization of Aegean olive oils with respect to their volatile compounds
Ilyasoglu, Huri; Ozcelik, Beraat; Hoed, Vera Van; Verhe, Roland
Cultivar characterization of Aegean olive oils (cv. Ayvalik and Memecik) based on their volatile compounds was carried out. The main volatile compounds detected in the Aegean olive oils were the C6 compounds derived from polyunsaturated fatty acids through the lipoxygenase pathway. The C6 aldehydes and C6 alcohols contributing to the green and fruity sensory notes of olive oil were determined in the Aegean olive oils as the major volatile compounds. Significant differences in the levels of hexanal, (E)-2-hexenal, 3-ethyl-1,5-octadiene and total compounds from linolenic acid were observed between Ayvalik and Memecik oils (p < 0.01). Principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to process the experimental data. The results of the chemometric analysis revealed that the two cultivars were clearly discriminated on the PC1-PC3 planes and LDA produced a 100% correct group classification.
- BildiriYalnız künye2011Environmental problems from the open dump in Gümüşhane Province and investigation of biological recycling for the organic solid wastes
Nas, S. Serkan; Bayram, Adem; Gokcekus, H; Turker, U; LaMoreaux, JW
This paper presents a general overview of current municipal waste management in Gümüşhane Province. Both the drawbacks of present disposal method are discussed and solution proposals are submitted. The solid waste samples, one sample in every week and total fifty two samples in a year, were taken from the municipal solid waste open dumping area during a year, 2004 March-2005 February. Compostable organic parts of the samples, separated from the mixed municipal solid waste, were analyzed in order to determine the suitability of composting for the disposal of municipal solid wastes in Gümüshane. The moisture content, C/N ratio and pH for all samples were determined and evaluated. The values with high moisture content being 78% (74% in spring, 83% in summer, and 78% in autumn and 77% in winter), relatively low C/N ratio being 21.6/1 (22.2/1 in spring, 16.2/1 in summer, 23.7/1 in autumn and 27.5/1 in winter), and low pH being 4.73 (5.50 in spring, 4.25 in summer, 4.45 in autumn and 4.72 in winter) disclose that composting of the organic wastes aren't suitable.
- MakaleYalnız künye2011Alternative gaseous fuels in port fuel injection spark ignition engines
Sezer, I.
This paper investigates the use of alternative gaseous fuels in port fuel injection spark ignition engines via the Lotus engine simulation program. To this end, the engine model for a port fuel injection spark ignition engine was designed, and engine performance was determined separately for gasoline and alternative gaseous fuels, i.e. compressed natural gas and liquefied petroleum gas. According to the results, brake thermal efficiency increases while engine performance and fuel consumption decrease with methane and propane when compared to gasoline under the same conditions. While a slight increase in the fuel/air equivalence ratio of gaseous fuels improves the engine performance, fuel consumption remains almost stable. Another factor that enhances engine performance is the increasing compression ratio for methane and propane. In this manner, performance values that are closer/equal to gasoline are achieved. Under these conditions, fuel consumption decreases notably, while significant increases are observed in brake thermal efficiency.
- BildiriYalnız künye2011Stable difference schemes for fractional parabolic PDE
Ashyralyev, Allaberen; Cakir, Zafer; Simos, TE
The stable difference schemes for the multidimensional fractional parabolic equation with Dirichlet and Neumann boundary conditions are presented. Stability estimates and almost coercive stability estimates with ln 1/τ+|h| for the solution of these difference schemes are obtained. A procedure of modified Gauss elimination method is used for solving these difference schemes of one-dimensional fractional parabolic partial differential equations.
- MakaleYalnız künye2011Preventive and protective effects of turkish propolis on H 2O 2-induced DNA damage in foreskin fibroblast cell lines
Aliyazicioglu, Yuksel; Demir, S.; Turan, I.; Cakiroglu, Tugba; Akalin, I.; Deger, O.; Bedir, A.
The aim of the present study was to evaluate the potential of Turkish propolis extracts if they prevent or protect foreskin fibroblast cells against hydrogen peroxide (H 2O 2)-induced oxidative DNA damage. Hydrogen peroxide (40 μM) was used as an inducer of oxidative DNA damage. The damage of DNA was evaluated by using the alkaline single cell gel electrophoresis (comet) assay. Turkish propolis extracts at concentrations of 25, 50, 75 and 100 μg/ml were prepared by ethanol. Anti-genotoxicity was assessed before, simultaneously, and after treatment of propolis extract (50 μg/ml) with H 2O 2. The results showed a significant decrease in H 2O 2-induced DNA damage in cultures treated with propolis extract. The antioxidant activity of phenolic components found in propolis may contribute to reduce the DNA damage induced by H 2O 2. Our findings confirmed the chemopreventive activity of propolis and showed that this effect may occur under different mechanisms.
- MakaleYalnız künye2011The effect of antifreeze admixtures on compressive strength of concretes subjected to frost action
Arslan, Metin; Çullu, Mustafa; Durmuş, Gökhan
This study aims to determine the effect of antifreeze admixture used in the concretes subjected to frost action on the concrete compressive strength. Three groups of concrete samples of C30 class were prepared with antifreeze admixtures by using the mixture of 30% calcium nitrate and 5% hydroxy ethoxy amin (A), calcium nitrate (B), Polyhydroxy amine (C). Concrete samples are put in the freezer in a fresh state 15 min after the mixing. Samples are subjected to frost action in 0, -5, -10, -15 and -20°C degrees for 48 hours. On the concrete samples water cured after 48 hours, compressive strength tests of 28 day are conducted. Consequently, it is seen that with the increase of the set temperature that concrete is cured, compressive strength of concrete is decreased and among all types of antifreezes the maximum decrease is seen between 0 and -5°C while the decrease in compressive strength is relatively less for -10, -15 and -20°C.
- MakaleAçık Erişim2011Heat and drought resistance criteria in spring bread wheat (Triticum aestivum L.): Morpho-physiological parameters for heat tolerance
Bahar, Bilge; Yildirim, Mehmet; Yucel, Cemal
This study was aimed at evaluating some morpho-physiological parameters such as stomatal conductance (gs), canopy temperature (CT), canopy temperature depression (CTD) and stay green duration (SGD) in terms of heat tolerance. For this purpose, trials designed according to randomized complete blocks were conducted with twenty-four spring bread wheat genotypes as three replicated in the Research and Application Area of Field Crops Department of Agricultural Faculty of Cukurova University in 2002 to 2003 and 2003 to 2004 growth seasons. The measurements of gs were made at two different dates at heading stage in 2003 to 2004 growth season. CT was measured at two growth stages (late milky and soft dough) in 2002 to 2003 (first) season and it was also measured at two different hours at the complete heading stage in 2003 to 2004 (second) season. CTD was measured at two different hours at the complete heading stage in the second season. The other morpho- physiological parameter was SGD, which was determined in the first growth season. As a result: (1) The high gs values were observed at both measuring dates even though there was no significant differences among the genotypes; (2) CT showed significant differences except T2 measurement in 2003 to 2004 season, yet significant negative correlations were found between CT and grain yield (GY) in 2003 to 2004 season and in general mean; (3) Despite not being significant differences among the genotypes, a strong positive correlation was found between CTD and GY; (4) In spite of the fact that genotypes did not show any statistical differences, it was found that SGD had a negative significant correlation with CT but positive non-significant correlation with GY. It is concluded from assessments of all physiological traits that such genotypes as Kauz/Altar 84//Ads, Varona Cno 79, Mon's'/Ald's'//Bow's' and WL6718 can be high yielding even if under heat stressed conditions, and can be used as gene pool in wheat breeding programs for tolerance to heat stress.
- MakaleYalnız künye2011Application of cattle manure, zeolite and leonardite improves hay yield and quality of annual ryegrass (Lolium multiflorum Lam.) under semiarid conditions
Yolcu, Halil; Seker, Hayati; Gullap, M. Kerim; Lithourgidis, Anastasios; Gunes, Adem
A field experiment was conducted under semiarid conditions to investigate the effect of cattle manure (20 and 40 t ha -1), zeolite (250, 500 and 750 kg ha -1), and leonardite (250, 500 and 750 kg ha -1) applications on hay yield and nutrient quality of annual ryegrass. Application of manure, leonardite, and zeolite increased ryegrass hay yield by 4, 24 and 47%, respectively compared with the control. In all fertilizer levels, the crude protein (CP) content was greater than the control and increased as the level of each fertilizer was increased. Most fertilizer treatments (except from the first level of cattle manure) gave higher CP yield than the control. All fertilizers increased the content of K, S, Ca, Mg, Fe, Mn and B of ryegrass hay as compared with the control, whereas they had no significant effect on Cu and Zn content. The content of most minerals increased as the amount of manure and leonardite applications increased. In conclusion, all fertilizers (especially zeolite) showed great potential for use in organic agriculture as they can improve plant growth and soil conditions in the long term.
- MakaleYalnız künye2011The Sumela Monastery slope in Maçka, Trabzon, Northeast Turkey: Rock mass properties and stability assessment
Gelişli, Kenan; Şeren, Aysel; Babacan, Ali Erden; Çataklı, Aycan; Ersoy, Hakan; Kandemir, Raif
In 2001, rock falls occurred on the southern slope of the Sumela Monastery, which was built on a cliff in Trabzon, north east Turkey, and is visited by many tourists. Considering the steepness of the slope and difficulty of access, rock classifications were made based on seismic wave velocity, rock mass quality (Q), rock quality designation (RQD) and rock mass rating (RMR). The results indicated extremely poor to very poor rock in the cracked, fractured and weathered parts and poor to fair rock in the intact parts of the monastery slope. As a consequence, rock fall, slide and rolling may occur from time to time. These constitute a hazard to the facilities of the monastery and access paths. It is recommended that cracked areas are strengthened with cement-based materials, that accumulated rocks are removed, and that retaining walls are constructed on solid rock around the unstable rock blocks.
- MakaleAçık Erişim2011Solution of nonlinear oscillators with fractional nonlinearities by using the modified differential transformation method
Merdan, Mehmet; Gökdoǧan, Ahmet
In this paper, an aproximate analytical method called the differential transform method (DTM) is used as a tool to give approximate solutions of nonlinear oscillators with fractional nonlinearites. The differential transformation method is described in a nuthsell. DTM can simply be applied to linear or nonlinear problems and reduces the required computational effort. The proposed scheme is based on the differential transform method (DTM), Laplace transform and Padé approximants. The results to get the differential transformation method (DTM) are applied Padé approximants. The reliability of this method is investigated by comparison with the classical fourth-order Runge-Kutta (RK4) method and Cos-AT and Sine-AT method. Our the presented method showed results to analytical solutions of nonlinear ordinary differential equation. Some plots are gived to shows solutions of nonlinear oscillators with fractional nonlinearites for illustrating the accurately and simplicity of the methods.
- MakaleYalnız künye2011Microwave assisted essential oil analysis and antimicrobial activity of M. alpestris subsp. alpestris
Cansu, Tayyibe Beyza; Yücel, Murat; Sinek, Kadriye; Baltaci, Cemalettin; Karaoglu, Sengül Alpay; Yayli, Nurettin
The present work describes the chemical composition and antimicrobial activity of the essential oil of Myosotis alpestris F.W. Schmidt subsp. alpestris (Boraginaceae). The essential oil was obtained from all parts of the plant by microwave distillation and analyzed by GCFID and GC-MS. Forty-seven components representing 88.2 % of the total oil were characterized and the main components of this species were found to be n-nonanal (11.8 %), decanal (10.8 %), n-octanal (10.7 %), hexahydrofanesyl acetone (6.6 %), o-cymene (3.9 %), tetradecanal (3.7 %), eicosanol (2.2 %) and E-β-farnesene (2.0 %). The isolated essential oils of M. alpestris subsp. alpestris was tested for antimicrobial activity against the bacteria Escherichia coli, Yersinia pseudotuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Mycobacterium smegmatis and the fungus Candida albicans and Saccharomyces cerevisiae at maximum essential oil concentration in hexane of 1000 μg/mL and they showed only antibacterial activity against fungus bacteria.
- MakaleYalnız künye2011Assessment of nonlinear seismic performance of a restored historical arch bridge using ambient vibrations
Sevim, Bariş; Bayraktar, Alemdar; Altunişik, Ahmet Can; Atamtürktür, Sezer; Birinci, Fatma
Historic masonry arch bridges are vital components of transportation systems in many countries worldwide, ensuring the ready access of goods and services to millions of people. The structural failure of these historic structures would severely and adversely impact the economies of these nations due to the massive disruptions of transportation systems accompanying such failures. To successfully maintain these aging masonry structures, performance assessment must incorporate the unique mechanical characteristics of masonry. Therefore, the preferred analysis technique must go beyond a linear approach. This study assesses the earthquake performance of a restored historical masonry arch bridge through nonlinear finite element analysis incorporating the Drucker-Prager damage criterion. The case study structure is the Mikron Arch Bridge, a nineteenth century Ottoman Era structure built over the Firtina River near Rize, Turkey, and restored in 1998. The Mikron Arch Bridge was first subjected to ambient vibration testing, during which accelerometers were placed at several points on the bridge span to record the bridge vibratory response. The investigators then used Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques to extract the experimental natural frequencies, mode shapes, and damping ratios from these measurements. Experimental results were compared with those obtained by the linear finite element analysis of the bridge. Good agreement between mode shapes was observed during this comparison, though natural frequencies disagree by 8-10%. The boundary conditions of the linear finite element model of Mikron Arch Bridge are adjusted such that the analytical predictions agree with the ambient vibration test results. By introducing the Drucker-Prager damage criterion, the calibrated linear FE model was next extended into a nonlinear model. Nonlinear analysis of seismic behavior of Mikron arch bridge was performed considering the acceleration record of Erzincan earthquake in 1992 that occurred near the Mikron Bridge region. The displacement and stress results were observed to be allowable level of the stone material. Moreover, linear FE model calibrations elicited a significant influence on the nonlinear FE model simulations.
- MakaleAçık Erişim2011Synthesis, characterization and catalytic investigation of novel polymeric thiourea
Saribiyik, O.Y.; Serin, S.
In this study, in order to obtain polymeric thiourea compounds which have unsolubulity properties and higher metal content, new reaction pathways based on the use of the template effect were investigated. For this purpose, the reactions between different diamines, such as ethylendiamine, ortho (o-) and para (p-) phenylenediamine, and carbon disulfide (CS2) were investigated and optimized by using the template effect of Ni(II). Catalytic activity of the polymeric structure on oxidation of styrene was also investigated in terms of different parameters such as heat (25 and 80° C), time (4 and 8 h), oxidant hydrogen peroxide (H2O2), tert-butyl hydroperoxide (TBHP), di-tert-butyl peroxide (DtBP) and solvent (acetonitrile and benzene). The products have been characterized on the basis of analytical and spectral method, Fourier transform infrared spectroscopy, 1H- and 13C-nuclear magnetic resonance, gel-permeation chromatography, elemental analysis, thermogravimetric analysis, atomic adsorbtion spectrometry, gas chromatography and gas chromatography mass spectrometry.
- MakaleYalnız künye2011Applicability of excavatability classification systems in underground excavations: A case study
Kaya, Ayberk; Bulut, Fikri; Alemdaǧ, Selçuk
In this study, applicability of the excavatability classification systems in underground excavations is investigated. For this purpose, the entrance portal of the Konakönü (Arakli{dotless}-Trabzon) tunnel, excavated in volcanic rocks within the scope of Black Sea coastal highway project, is chosen as pilot study area. The entrance portal of tunnel is excavated through the rocks of Eocene-aged Kabaköy formation of basaltic-andesitic tuffs, aglomerate and basalt. In excavation, basaltic and andesitic tuffs were ripped by using hydraulic breaker; aglomerate and basalt were excavated by using explosives. Based on the results obtained from field and laboratory studies, rock masses are classified in terms of excavatability. According to Pettifer and Fookes (1994), basaltic and andesitic tuffs are included in "hard ripping", aglomerate and basalt in "blasting required" categories. With reference to Tsiambaos and Saroglou (2009), basaltic and andesitic tuffs fall in "ripping", agglomerate and basalt in "hammer and blasting" categories. It was found out that the classifications made according to these two methods are completely compatible with in-situ excavation works. Also, it is determined that the parameters give the best results for determining excavation class in underground excavations are GSI (Geological Strength Index), I s (50) (Point load strength index) and I f (Discontinuity spacing index).
- MakaleYalnız künye2011An approximate solution of a model for HIV infection of CD4+ T cells
Merdan, M.; Gokdogan, A.; Erturk, V.S.
In this paper, the approximate solution of the differential system modeling HIV infection of CD4+ T cells is obtained by a reliable algorithm based on an adaptation of the standard variational iteration method (VIM), which is called the multi-stage variational iteration method(MSVIM). A comparison between MSVIM and the fourthorder Runge-Kutta method (RK4-method) reveal that the proposed technique is a promising tool to solve the considered problem.
- MakaleYalnız künye2011Experimental and analytical system identification of Eynel arch type steel highway bridge
Altunişik, Ahmet Can; Bayraktar, Alemdar; Sevim, Bariş; Özdemir, Hasan
This paper describes a full scale arch type steel highway bridges, its finite element modelling and Operational Modal Analysis. Eynel Highway Bridge which has arch type structural system with a total length of 336 m and located in the AyvacIk county of Samsun, Turkey is selected as a case study. The bridge connects the villages which are separated with Suat Uǧurlu Dam Lake. The three dimensional finite element model is constructed using project drawings and an analytical modal analysis is then performed to generate natural frequencies and mode shapes in the three-orthogonal directions. The ambient vibration tests on the bridge deck under natural excitation such as traffic, human walking and wind loads are conducted using Operational Modal Analysis. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, two output-only system identification methods are employed namely, Enhanced Frequency Domain Decomposition method in the frequency domain and Stochastic Subspace Identification method in time domain. The correlation between the finite element model and experimental results is studied. Good agreement is found between dynamic characteristics in the all measurement test setups performed on the bridge deck. It is demonstrated that the ambient vibration measurements using Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are enough to identify the most significant modes of steel highway bridges. It is seen that there are some differences between analytical and experimental natural frequencies and experimental natural frequencies are generally bigger than the others.