Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(66)
- Merdan, Mehmet(56)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(42)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Ashyralyyev, Charyyar(34)
- Dokuz, Abdurrahman(33)
- Araz, Onur(31)
- Öztürk, Serkan(31)
- Sipahi, Ferkan(30)
- Kandemir, Raif(28)
- Arslan, Mehmet(27)
- Karsli, Orhan(27)
- Kulakaç, Nurşen(26)
- Baltacı, Cemalettin(25)
- Gücer, Mehmet Ali(25)
- Kurt, Kemal(25)
- Maden, Nafiz(25)
- Ozturk, Samet(25)
- Topal, Fevzi(25)
- Baltaci, Cemalettin(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Bayrakdaroglu, Serdar(23)
- Kankal, Murat(23)
- Peker, Iskender(23)
- Yolcu, Halil(23)
- Reis, Hatice Catal(21)
- Topal, Meryem(21)
- Vural, Alaaddin(21)
- Aydin, Aydanur(20)
- Aydin, Faruk(20)
- Bayraktar, Alemdar(20)
- Kurnaz, Muammer(20)
- Çelik, Necati(20)
- Ürkek, Bayram(20)
- Cakir, Tufan(18)
- Günen, Mehmet Akif(18)
Yayınlar
- MakaleAçık Erişim2013Scopus SJRQ2Development of a new solid phase extraction procedure for selective separation and enrichment of Au(III) ions in environmental samples
Elvan, Hamide; Ozdes, Duygu; Duran, Celal; Bulut, V. Numan; Gümrükçüoglu, Nurhan; Soylak, Mustafa
A highly sensitive, selective and low cost solid phase extraction (SPE) procedure was developed for separation and enrichment of Au(III) ions in environmental samples prior to its flame atomic absorption spectrometric detection. Au(III)-2-pyridin-5-(4-tolyl)-1,3,4-oxadiazole (PYTOX) complex was adsorbed quantitatively on Amberlite XAD-4 resin in 0.5 mol L-1 HNO3 condition and the elution was carried out with 7.5 mL of 1.0 mol L-1 HCl in acetone. Some analytical parameters, affect the recoveries of Au(III) ions, such as HNO3 concentration of sample solution, amount of PYTOX, type, concentration and volume of eluent, sample volume and concomitants were examined. Adopting optimized experimental conditions, the limit of detection for Au(III) ions was 1.03 μg L-1 with preconcentration factor of 50 and a relative standard deviation (RSD) of 3.7%. The determination of Au(III) ions in anodic slime, gold ore, soil and sea and stream waters was performed after checking the accuracy of the method by addition-recovery tests.
AtıfScopus7WoS7OpenAlex6
İncele - MakaleYalnız künye2013Scopus SJRQ2Decaying source model: Alternative approach to determination of true counting rates at X and gamma ray counting systems
Karabidak, S.M.; Cevik, U.
The counting systems consisting of electronic devices are used for detection of radiation due to X or gamma rays. The dead time of the counting system is based on time limitations of these electronic devices. The dead time causes counting losses. Determination of counting rate losses in quantitative and qualitative analysis become a vital step for correction of analysis. Therefore, compensating for counting rate losses is of great importance. These counting rate losses are due to piled up reject time, paralyzable or non-paralyzable system dead time or a combination of these mechanisms. Paralyzable and non-paralyzable models are well-known and frequently used for correction of counting rate losses dependent on the system dead time. However, these two models do not provide enough correction at medium and high counting rates. Therefore, the new models for corrections of counting rate losses are needed. For this reason, both an alternative approach is proposed and a simulation program is coded for counting rate losses in this study. A good agreement is obtained between theoretical model and simulation program.
AtıfScopus7WoS6OpenAlex9İncele - MakaleAçık Erişim2013Scopus SJRQ4Effect of some spice essential oils on the stability of frying oils
Tanriverdi, Ebru Sandal; Özcan, Mehmet Musa; Juhaimi, Fahad Al
In this study, peppers and potatoes were fried in olive and peanut oils. In order to evaluate the oxidative stability of frying oils, essential oils of sage, rosemary, thyme at the concentration of 0.3, 0.6, 0.9 and 1.2 %, separately and 0.01 % butylated hydroxytoluene were added into olive and peanut oils. Chemical properties of frying oils (free fatty acid %, peroxide value, DPPH, total phenolic and fatty acid composition) were determined after frying. Butylated hydroxytoluene showed the best effect on free fatty acid % and peroxide value of olive oils after frying of peppers and potatoes. Free fatty acid % values of frying oils of peppers and potatoes showed variation. The nearest values of oleic, linoleic and linolenic acid contents of frying olive oils of peppers and potatoes were determined with sample addition of butylated hydroxytoluene. Oleic, linoleic and linolenic acid contents of peanut oil with butylated hydroxytoluene and potato frying oil that addition of 0.3 % rosemary essential oil were determined to nearly the initial value of oil. These essential oils were also determined to show high radical scavenging effect. Rosemary essential oil was determined higher the radical scavenging effect and lower total phenolic compounds than thyme essential oils. There were not exact a relationship between radical scavenging effect and the amount of total phenolic compounds. The aim of current study is to establish to the effect of some spice essential oils on the stability of frying oils.
- MakaleYalnız künye2013Scopus SJRQ1Effects of charge properties on exergy balance in spark ignition engines
Sezer, Ismet; Bilgin, Atilla
This study investigates the effects of the air-fuel mixture (charge) properties on the exergy balance in spark ignition engines. A thermodynamic cycle model including compression, combustion and expansion processes is used. The principles of the second law are applied to the cycle model to perform an exergy analysis. Variation of the exergetic variables during the investigated portion of the cycle are examined as a function of the charge properties, i.e., fuel-air equivalence ratio, residual gas fraction and initial charge temperature. The results show that increasing fuel-air equivalence ratio causes an increase in irreversibilities and also exergy losses with heat transfer and exhaust gases, but enriching the air-fuel mixture beyond the stoichiometric ratio makes no significant contribution to the exergy transfer with work transfer. A slightly lean mixture also gives the best first and second law efficiencies. It is observed that there is a linear relation between the residual gas fraction and the exergetic variables. An increase in the residual gas fraction decreases the irreversibilities and exergy losses aside from the exergy transfer with work transfer. However, increasing the residual gas fraction positively affects the first and second law efficiencies because of the diluting of the charge. Increase of initial charge temperature creates a reduction in the irreversibilities and the exergy losses and, it also results in a lower exergy output by work transfer. Further, increase of initial charge temperature negatively influences the first and second law efficiencies.
AtıfScopus32WoS28OpenAlex40İncele - MakaleYalnız künye2013Scopus SJRQ2Effects of different curvature patches on the strength of double-strap adhesive joints
Akpinar, Salih
In general, the damage in adhesively bonded joints initiates from and propagates through the ends of the overlap area due to high stress concentration in that area. The reduction of these stress concentrations results in an increase in the strength of the joints. For this reason, the rounding of the overlap region before bonding and then applying compression during the bonding process will exert compressive residual stresses on the adhesive layer in the overlap end regions. It is known that the residual stresses formed in this process increase the failure strength of the joint and hence delay the initiation of the damage. In this study, the effects of overlap length (L = 50,75, and 100 mm), patch thickness (h = 1.6, 3.2, and 5 mm) and patch materials (AA2024 aluminum alloy, AISI 304 steel, AISI 1040 steel) on bond strength were experimentally investigated for adhesively bonded double-strap joint (DSJ) and curvature double-strap joint (CDSJ) subjected totensile loading. The experimental study showed that the overlap length, patch thickness and patch materials have considerable influence on the failure strength and displacement capacity of the joints.
AtıfScopus31WoS29İncele - MakaleYalnız künye2013Scopus SJRQ1Prediction of offshore bar-shape parameters resulted by cross-shore sediment transport using neural network
Kömü rcü, Murat Ihsan; Kömür, Mehmet Aydin; Akpinar, Adem; Özölçer, Ismail Hakki; Yüksek, Ömer
In order to understand the features of coastal zone and to utilize the coastal areas, it is necessary to determine the sediment movement and the resulting transport. Waves, topographic features, and material properties are known as the most important factors affecting the sediment movement and coastal profiles. In this study, by taking into consideration of wave height and period (H0, T), bed slope (m) and sediment diameter (d50), cross-shore sediment movement was studied in a physical model and various bar-shape parameters of the resultant erosion type profile were determined. Using 80 experimental data which are obtained from physical model studies, a neural network (NN) has been calibrated to predict bar-shape parameters of beach profiles. A sensitivity analysis was firstly carried out to decide data of training and test sets. Four different models, in which the rates of their training and testing set data were 80% and 20%, 70% and 30%, 60% and 40%, 50% and 50% were constituted and their performances were compared. It was determined that the model, in which the rate of its training and testing set data was 80% and 20%, respectively, has the best results. Therefore, a total of 64 experimental data were used as training set and the remainders of the experimental data were used as a testing set for the model. The performance of the NN model was compared with the regression equations developed in a previous study and the equations cited in literature indicating better performance over the equations.
AtıfScopus16WoS14OpenAlex22İncele - BildiriYalnız künye2013Self-deploying composite shell reflector antenna for Ku-band missions: 1.5 m diameter demonstrator
Soykasap, Omer; Karakaya, Sukru; Kaplan, Erdar; Ilarslan, M; Ince, F; Kaynak, O; Basturk, S
Carbon fiber reinforced plastic (CFRP) composite shell reflectors have been developed for space borne antennas due to their light weight, high thermal stability, and high surface accuracy. In order to reduce launch cost and structural mass, compactly folding and self-deployment of the reflector is preferred. In this paper, the full-scale offset reflector with a diameter of 6 m was designed by introducing reinforcements in the central region. After modal analysis was carried out for full-scale reflector model, the suitability of design was determined and 1/4-scaled version was manufactured. The experiments of the demonstrator were conducted for modal analysis, folding, dynamic deployment behavior and surface accuracy. As a result of study, new reflector model was successfully designed with low-mass, manufacturing ease, lower cost and has a monolithic structure, which two opposite edges of the reflector can be rolled toward the center of the reflector for packaging.
AtıfScopus4WoS3İncele - MakaleYalnız künye2013Scopus SJRQ3Heavy metal analysis by moss species in the Black Sea region of Turkey
Koz, Bahadir; Cevik, Ugur; Bulut, Volkan Numan; Kaya, Selim; Gundogdu, Ali; Celik, Necati
The heavy metal analysis of mosses in the Black Sea region of Turkey was determined using atomic absorption spectrometry method. The procedure was also validated by analysis of standard reference material (IAEA-336 Lichen). A qualitative analysis showed that the samples contained chromium, manganese, cobalt, nickel, copper, zinc, and lead. While the mean concentration values of Cr, Mn, Co, Ni, Cu, Zn, and Pb in the moss samples collected from city centers are 60.6, 820, 12.2, 18.8, 293, 181 and 39.8 mg.kg-1, the mean concentration values in the moss samples collected from the city intervals are 43.8, 761, 11.0, 15.6, 242, 170 and 38.4 mg.kg-1, respectively. Since this study was a heavy metal analysis along the highway, evaluation of these elements with their potential hazards for ecology and human was briefly discussed. A strong relationship was observed between Pb concentration and the traffic density.
AtıfScopus2WoS2İncele - MakaleAçık Erişim2013Scopus SJRQ2Simulation of a large electric distribution system having intensive harmonics in the industrial zone of Konya
Eroǧlu, Hasan; Aydin, Musa
In this study, measurements were taken at difierent points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. With the help of this study, advanced analysis can be performed in the electrical distribution system for power quality analyses and this study can be a background for similar kinds of simulation studies.
AtıfOpenAlex1
İncele - MakaleAçık Erişim2013Scopus SJRQ1Petrogenesis of the late Cretaceous Turnagöl intrusion in the eastern Pontides: Implications for magma genesis in the arc setting
Kaygusuz, Abdullah; Sipahi, Ferkan; Ilbeyli, Nurdane; Arslan, Mehmet; Chen, Bin; Aydinçakir, Emre
A series of Cretaceous plutons is present in the eastern Pontides of northeastern Turkey. The Turnagöl intrusion is the least studied and, thus, the least understood plutons in the orogen. This intrusion consists of hornblende-biotite granodiorites emplaced at 78 Ma based on LA-ICP-MS U-Pb zircon dating. It is of sub-alkaline affinity, belongs to the medium- to high-K calc-alkaline series, and displays features typical of I-type granites. The rocks of the intrusion are enriched in large-ion lithophile elements and light rare earth-elements with negative Eu anomalies (Eu/Eu* = 0.69-0.82), but are deficient in high-field-strength elements. They have a small range of ( 87Sr/86Sr)i (0.7060-0.7063), ÉNdi(-2.6 to -3.1), and δ18O (+8.1 to +9.1) values. Their Pb isotopic ratios are 206Pb/204Pb = 18.63-18.65, 207Pb/ 204Pb = 15.62-15.63, and 208Pb/204Pb = 38.53-38.55. The fractionation of plagioclase, hornblende, and Fe-Ti oxides had key functions in the evolution of the Turnagöl intrusion. The crystallization temperatures of the melts ranged from 758 to 885 C as determined by zircon and apatite saturation thermometry. All these characteristics, combined with the low values of K2O/Na2O and (Na 2O + K2O)/(FeOt + MgO + TiO2), as well as the high values of (CaO + FeOt + MgO + TiO2), suggest an origin by dehydration melting from a metabasaltic lower crustal source.
AtıfScopus54WoS49OpenAlex60İncele - MakaleYalnız künye2013Scopus SJRQ1Probabilistic sensitivity analysis of suspension bridges to near-fault ground motion
Çavdar, Özlem
The sensitivities of a structural response due to variation of its design parameters are prerequisite in the majority of the algorithms used for fundamental problems in engineering as system uncertainties, identification and probabilistic assessments etc. The paper presents the concept of probabilistic sensitivity of suspension bridges with respect to near-fault ground motion. In near field earthquake ground motions, large amplitude spectral accelerations can occur at long periods where many suspension bridges have significant structural response modes. Two different types of suspension bridges, which are Bosporus and Humber bridges, are selected to investigate the near-fault ground motion effects on suspension bridges random response sensitivity analysis. The modulus of elasticity is selected as random design variable. Strong ground motion records of Kocaeli, Northridge and Erzincan earthquakes are selected for the analyses. The stochastic sensitivity displacements and internal forces are determined by using the stochastic sensitivity finite element method and Monte Carlo simulation method. The stochastic sensitivity displacements and responses obtained from the two different suspension bridges subjected to these near-fault strong-ground motions are compared with each other. It is seen from the results that near-fault ground motions have different impacts stochastic sensitivity responses of suspension bridges. The stochastic sensitivity information provides a deeper insight into the structural design and it can be used as a basis for decision-making.
AtıfScopus12WoS9OpenAlex9İncele - MakaleYalnız künye2013Scopus SJRQ2Increasing single-lap joint strength by adherend curvature-induced residual stresses
Temiz, Ş.; Akpinar, S.; Aydin, M.D.; Sancaktar, E.
Single-lap joint (SLJ) geometry is the most widely used type of adhesive joint geometry. In this joint, peel stresses occur at the overlap ends due to load eccentricity and the presence of shear-free adhesive termination surfaces. These peel stresses, along with the transverse tensile stresses which occur along the overlap longitudinal axes, and adhesive shear stresses, ultimately cause joint failure. Obviously, reductions in these stresses should result in higher joint strength and increased load capacity. To this end, we exploited elastic spring-back capability of (steel) metal adherends by initially forming curved segments of varying arc lengths and radii at overlap ends. These adherends with curved-end sections were then bonded in single-lap configuration, simply by applying sufficient bonding pressure to elastically flatten the curved segments to result in typically flat overlap sections subsequent to adhesive cure and the removal of bonding pressure. Since the elastic adherend overlap ends tend to revert back to their initial curved form, they exert compressive residual stresses on the adhesive layer in the overlap end regions. We determined that the compressive residual stresses induced in this fashion considerably increased the load capacity of SLJs subjected to tension.
AtıfScopus18WoS18İncele - MakaleAçık Erişim2013Scopus SJRQ2Testing for causality between the foreign direct investment, current account deficit, GDP and total credit: Evidence from G7
Akbas, Yusuf Ekrem; Senturk, Mehmet; Sancar, Canan
In this study, countries were analyzed between 1990 and 2011 in order to determine whether a causal relationship exists among current account deficit, GDP, foreign direct investment, and total credits of G7. Analysis took into account the cross-sectional dependence and was applied to test the causality among the variables form the panel. Firstly, panel unit root tests were used for determining stationary of variables. As a result of the panel unit root tests, it was found that GDP and foreign direct investment have a stationary structure and that total credits and current account deficit contain unit root. In order to see whether there is a long-term relationship among the variables or not, the panel co-integration test was used. As a result of the test, it was concluded that there is a co-integration relationship among the series. The possibility of a causal relationship was analyzed among the variables using the causality test developed by Elena Ivona Dumitrescu and Christophe Hurlin (2012). Results of the analysis showed a unidirectional causal relationship from current account deficit and foreign direct investment to GDP. Bidirectional causality was found between current account deficit and total credits. Finally, a unidirectional relationship was found from foreign direct investment to current account deficit and total credits.
AtıfScopus25WoS26OpenAlex63İncele - MakaleYalnız künye2013Scopus SJRQ1Assessment of wave energy resource of the Black Sea based on 15-year numerical hindcast data
Akpinar, Adem; Kömürcü, Murat I.hsan
In this study, the existence and variability of wave energy resource potential of the Black Sea based on 15-year hindcast data is described in detail. The hindcasts of wave parameters were carried out by using the third generation wave prediction model (Simulated WAves Nearshore - SWAN), which is one of the most popular numerical wave models and has been widely used for estimating ocean waves. The model was forced with the ECMWF ERA Interim wind fields and applied with a spatial resolution of about 0.0167°. ×. 0.0167° and a model time step of 6. h to resolve efficiently offshore and nearshore wave conditions. The results were presented in the form of charts of the spatial distribution of significant wave height and wave power, on a monthly, seasonal and annual basis. Annual energy was calculated in the study region with the hindcast data set covering 15. years (1995-2009). The areas with the highest wave energy resource were determined and the south west coasts of the Black Sea are suggested as the best site for the installation of a wave farm. It was determined the western parts of the Black Sea (especially the south-west) are exposed to energetic waves more than the eastern parts.
AtıfScopus167WoS155OpenAlex180İncele - MakaleYalnız künye2013Scopus SJRQ1Production of human fat milk analogue containing α-linolenic acid by solvent-free enzymatic interesterification
Ilyasoglu, Huri
Human milk fat (HMF) analogue was synthesized by lipase-catalysed interesterification of tripalmitin with extra virgin olive oil, and flaxseed oil in a solvent-free media. Lipozyme® TL IM, immobilized sn-1,3 specific lipase, was used as biocatalysts. Substrate molar ratio, reaction temperature and reaction time were used to model and to optimize the reaction conditions via response surface methodology. Good quadratic models were obtained for the incorporation of palmitic acid and α-linolenic acid. At the optimal conditions generated from the model, the palmitic acid and α-linolenic acid contents of the product were found to be 25.2g/100g and 15.9g/100g, respectively. The chemical properties (free fatty acid, iodine value, and saponification value), sn-2 positional fatty acid composition, and sterol composition of the final structured lipid (SL) were determined. Furthermore, the oxidative stability of the SL and the SLs with antioxidants (BHT, gallic acid, and rosemary extract) was evaluated. The peroxide and thiobarbituric acid reactive substances (TBARS) values of the SLs showed they had antioxidant activity on the SL. The HMF analogue synthesized in this study may have potential use in infant formulas to provide omega-3 fatty acids (α-linolenic acid).
AtıfScopus18WoS14OpenAlex19İncele - MakaleAçık Erişim2013Scopus SJRQ4Evaluation of protein tyrosine phosphatase activity in patients with acute leukemia
Akdogan, Elif; Cengiz, Sevil; YIlmaz, Mustafa; Sönmez, Mehmet; Durmus, Ahmet; Oval, Ercüment; Omay, Serdar Bedii
Protein tyrosine phosphatases regulate physiological processes including growth, differentiation, metabolism and the cell cycle. Together with tyrosine kinases, they control the phosphorylation state of tyrosine residues of signaling proteins. An increased level of protein phosphorylation results in abnormal proliferation and many cancer types show a mutation or deletion of a protein tyrosine phosphatase gene. In this study we evaluated the protein tyrosine phosphatase activity in acute leukemia patients. Tyrosine phosphatase activity in bone marrow mononuclear cells of acute leukemia patients was measured using a tyrosine phosphatase assay system kit and compared with a control group. We found that tyrosine phosphatase activity in acute leukemia patients was high compared to the controls. According to subgroups of acute leukemia, tyrosine phosphatase activity in the AML-M2 subgroup was high compared to the controls. The effect of increased level of protein tyrosine phosphatase activity on leukemogenesis needs further evaluation. Studies in a large group of patients are needed to emphasize the importance of tyrosine phosphatase activity in acute leukemia patients.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2013Scopus SJRQ1The effects of high temperature on mechanical properties of cementitious composites reinforced with polymeric fibers
Çavdar, Ahmet
Polymeric fibers are cheap and popular materials used in the concrete industry, and they may improve the mechanical properties of cementitious composites under high temperature. In this study, three different types of polymeric fibers - Copolymer Polypropylene/polyethylene (CPP), Homopolymer Polypropylene (HPP), and Aramid (AR) - are added to cement mortars with the aim to investigate their mechanical contributions to mortars under high temperature, comparatively. These fibers are added into mortars in five different ratios (0.0%, 0.3%, 0.6%, 0.9% and 1.2%) by volume. The mortars are subjected to following temperatures: 21 °C (normal conditions), 100 °C (oven dry), 450 °C, 650 °C and 850 °C. It is concluded that polymeric fibers used in this study contribute to the flexural strength of mortars under normal dry conditions (100 °C). This effect continues clearly up to 450 °C and polymeric fibers show effects on flexural strength especially at 450 °C. Each fiber shows the best performance different addition ratio when flexural and compressive strength are taken into consideration at the same time under high temperature. The highest increase in flexural strength and the lowest decrease in compressive strength are at 0.3-0.9% fiber addition ratio for HPP, at 0.3-0.6% fiber addition ratio for CPP and at 0.9% fiber addition ratio for AR for every temperature.
AtıfScopus57WoS56OpenAlex59İncele - MakaleAçık Erişim2013Scopus SJRQ1A study on 3-D stress distributions in the bi-adhesively bonded T-joints
Akpinar, Salih; Aydin, Murat Demir; Özel, Adnan
In this study, the normal (σx,. σy,. σz) and shear stress (τxy,. τyz,. τzx) distributions occurring in a bi-adhesively bonded T-joint with was investigated via a non-linear three dimensional finite element analysis. For this purpose, first of all, using 2024-T3 aluminum alloy as the adherend and the support, a two-part paste (DP 460) and a film type (SBT 9244) as adhesive, two different types of T-joint samples (single-adhesively bonded T-joint and bi-adhesively bonded T-joint) were produced for experimental studies. After experimental studies on the three different T-joint types were conducted, stress analyses in the T-joints were performed with a three-dimensional finite element analysis by considering the geometrical non-linearity and the material non-linearities of the adhesive (DP460 and SBT9244) and adherend (AA2024-T3). Finally, for a given adherend, the lower the stiffness of the adhesive used in the overlap, the lower the stress concentration, leading to potentially higher joint strength. The use of relatively low stiffness adhesives at the ends of the overlap in a bi-adhesive can decrease the stress concentration and, therefore, potentially lead to higher joint strength.
AtıfScopus47WoS40OpenAlex50İncele - MakaleYayıncıda açık erişim2013Scopus SJRQ4Serum anti-carbonic anhydrase I and II antibodies and polycystic ovary syndrome; [Serum anti-karbonik anhidraz I ve II antikorları ve polikistik over sendromu]
Menteşe, Ahmet; Güven, Süleyman; Sümer, Ayşegül; Turan, Ibrahim; Demir, Selim; Karahan, Süleyman Caner; Alver, Ahmet
Aim: The aim of this study is to investigate anti-carbonic anhydrase antibodies (anti-CA I and CA II antibodies) in the sera of women with polycystic ovary syndrome (PCOS). Methods: In this study serum anti-CA I and II antibody levels of age and BMI matching fifty women with PCOS and fifty women without PCOS on day three of menstrual cycle were assessed with an ELISA method previously developed by Hosoda and modified by Alver et al. Results: The mean serum anti-CA I antibody levels were significantly higher in women with PCOS and anti-CA II antibody levels were not significantly different in women with PCOS compared with control subjects. For serum anti-CA I antibody, the absorbance higher than 0.484 (mean + 3SD of control subjects) was taken as positive, Anti-CA I antibody was detected in 13 of 50 patients with PCOS (26%). Considering serum anti-CA II antibody, the absorbance higher than 0.654 (mean + 3SD of control subjects) was taken as positive. Anti--CA II antibody was detected in 2 of 50 patients with PCOS (4%). All patients with positive anti-CA II antibody also had positive anti-CA I antibody. Autoantibodies specifically reactive to CA I were found to be present at a higher frequency than CA II in the serum of subjects with PCOS in the present study. Conclusion: The results may suggest that autoimmune responses against CA I may be involved in the pathogenesis of PCOS.
AtıfScopus9WoS7OpenAlex8İncele - MakaleYalnız künye2013Scopus SJRQ13-D non-linear stress analysis on the adhesively bonded T-joints with embedded supports
Akpinar, Salih; Aydin, Murat Demir; Temiz, Şemsettin; Özel, Adnan
In the present study, it is aimed to compare mechanical behaviors of T-joint types with embedded and non-embedded supports subjected to bending moment. For this purpose, after experimental studies on the two different T-joint types were conducted, stress analyses in the T-joints were performed with a three-dimensional finite element method by considering the geometrical non-linearity and the material non-linearities of the adhesive (DP460) and adherend (AA2024-T3). Finally, stress analyses and experimental results show that the variation of the geometry of the bonding zone, e.g., embedding the supports, would change the stress distributions and strength of the joint. Additionally, it is seen that T-joints with embedded supports carry 30% more load than T-joints with non-embedded supports although their bending stiffnesses decrease.
AtıfScopus17WoS15OpenAlex19İncele