Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(67)
- Merdan, Mehmet(59)
- Duran, Celal(49)
- Ozdes, Duygu(46)
- Kaygusuz, Abdullah(45)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Karsli, Orhan(36)
- Öztürk, Serkan(35)
- Dokuz, Abdurrahman(34)
- Araz, Onur(32)
- Kandemir, Raif(31)
- Kulakaç, Nurşen(29)
- Sipahi, Ferkan(29)
- Arslan, Mehmet(27)
- Baltaci, Cemalettin(27)
- Baltacı, Cemalettin(27)
- Kurt, Kemal(27)
- Topal, Fevzi(27)
- Gücer, Mehmet Ali(25)
- Peker, Iskender(25)
- Aydin, Faruk(24)
- Bayrakdaroglu, Serdar(24)
- Maden, Nafiz(24)
- Ozturk, Samet(24)
- Vural, Alaaddin(24)
- Yolcu, Halil(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Kankal, Murat(23)
- Reis, Hatice Catal(23)
- Ürkek, Bayram(23)
- Günen, Mehmet Akif(22)
- Kurnaz, Muammer(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(21)
- Ashyralyyev, Charyyar(20)
- Aydin, Aydanur(20)
- Bayraktar, Alemdar(20)
Yayınlar
- MakaleYalnız künye2012Scopus SJRQ2Performance and emission studies of castor bean (Ricinus Communis) oil biodiesel and its blends with diesel fuel
Özcanli, M.; Serin, H.; Saribiyik, O.Y.; Aydin, K.; Serin, S.
An experimental study was conducted to evaluate the use of various blends of castor (Ricinus Communis) oil methyl ester with diesel fuel. Performance and exhaust emissions of castor oil biodiesel with diesel fuel in a commercial compression ignition engine were presented in this study. Biodiesel produced from castor oil was blended with diesel fuel at the volumetric ratios of 5% (B5), 10% (B10), 25% (B25), 50% (B50), and 100% (B100). Fuel properties of castor oil methyl ester and its blends with diesel fuel were stated. The performance results showed that blends of castor oil methyl ester with diesel provided an increase on brake specific fuel consumption and a small decrease on brake power output. Compared with diesel fuel, diesel-castor oil methyl ester blends showed that while the carbon monoxide and carbon dioxide emissions became reduced; the oxides of nitrogen emissions observed higher than diesel fuel emission characteristics. Test results showed that B25 was determined as a suitable alternative fuel for diesel engines.
AtıfScopus40WoS35OpenAlex39
İncele - MakaleYalnız künye2012Scopus SJRQ1A study on the effects of high temperature on mechanical properties of fiber reinforced cementitious composites
Çavdar, Ahmet
The flexural strength and ductility properties of cementitious composites (mortar) under high temperature may be significantly improved by incorporating different types of fibers. In this study, four different types of fibers are added to cement mortars with the aim to investigate their mechanical contributions to mortars under high temperature, comparatively. Polypropylene (PP), carbon (CF), glass (GF) and polyvinyl alcohol (PVA) fibers are chosen for research. These fibers are added into mortars in five different ratios (0.0%, 0.5%, 1.0%, 1.50% and 2.0%) by volume. The mortars are subjected to the following temperatures: 21°C (normal conditions), 100°C (oven dry), 450°C and 650°C. The mechanical properties investigated are flexural strength, deflection and compressive strength of the cement mortars. In addition, thin sections of mortars are investigated to obtain changes in mortar because of high temperature. It is concluded that all fiber types contribute to the flexural strengths of mortars under high temperature. However, this contribution decreases with an increase in temperature. The samples with PVA show the best flexural performance (75-150%) under high temperature. CF which does not melt under high temperature also gives high flexural strength (11-85%). The compressive strengths of the mortars reduce under high temperature or with fiber addition. The highest increase in flexural strength and the lowest decrease in compressive strength is at 0.5-1.5% for CF if all temperature conditions are taken into consideration. The optimum fiber addition ratios of the samples containing PP and GF are 0.5% by volume. And for PVA, it is between 0.5% and 1.5% by volume.
AtıfScopus173WoS152OpenAlex178İncele - MakaleAçık Erişim2012Scopus SJRQ2Determination of the dependence of HPGe virtual point detector location on source dimensions in 60 keV-2 MeV range using Monte Carlo simulation
Çelik, N.
The virtual point detector (VPD) concept for an HPGe detector with 55% relative efficiency was confirmed for bulky sources having different diameters and heights. After reproducing experimental data, Monte Carlo simulation was used to investigate the dependence of VPD location on photon energy for various source diameters and heights in the energy range from 60 keV to 2 MeV. The simulations were confirmed using a soil reference source prepared by International Atomic Energy Agency (IAEA). It was seen that increasing photon energy makes significant changes in VPD location up to 600 keV. It was observed that VPD locations increase with increasing source diameter and height. It was also seen that VPD locations were approximately linearly dependent on source diameters and heights.
AtıfScopus5WoS5OpenAlex6İncele - MakaleYalnız künye2012Scopus SJRQ4Artificial neural networks for estimation of temporal rate coefficient of equilibrium bar volume
Kankal, Murat; Kömürcü, Murat Ihsan; Yüksek, Ömer; Akpinar, Adem
Present study consists the growth of a bar profile caused by cross-shore sediment transport. This is especially on growth of bar volume (V) toward equilibrium bar volume (Veq). Three analysis methods being a power and linear regression analysis (PRA and LRA) and an Artificial Neural Network (ANN) analysis were performed to determine empirical temporal rate coefficient (α). Forty-two experimental data were used for training set and the rest of the experimental data were used for testing set in the ANN analysis. As the results of analyses, the smallest average relative and root mean square error (RMSE) computed for the ANN methods are 7.578% and 0.029, respectively. It has been obtained that the ANN analysis, which is used for determination of α coefficient, gives reasonable results. Finally, bar volumes were calculated by means of computed α values and compared with the results of experimental data.
AtıfScopus3WoS5İncele - MakaleAçık Erişim2012Scopus SJRQ3Numerical approximations to the solution of ray tracing through the crystalline lens
Yildirim, A.; Gökdogan, A.; Merdan, M.; Lakshminarayanan, V.
An approximate analytical solution in the form of a rapidly convergent series for tracing light rays through an inhomogeneous graded index medium is developed, using the multi-step differential transform method based on the classical differential transformation method. Numerical results are compared to those obtained by the fourth-order Runge - Kutta method to illustrate the precision and effectiveness of the proposed method. Results are given in explicit and graphical forms.
AtıfScopus7WoS5OpenAlex6İncele - MakaleYalnız künye2012Scopus SJRQ2The effect of adding sour cherry pulp into yoghurt on the physicochemical properties, phenolic content and antioxidant activity during storage
Şengül, Memnune; Erkaya, Tuba; Şengül, Mustafa; Yildiz, Hilal
This study investigated the effect of adding sour cherry pulp into yoghurt on its physicochemical properties, phenolic content, antioxidant activity and sensory characteristics. Sour cherry pulp was added at 0%, 8%, 12% and 16% into the yoghurt, and measures were checked through 14days cold storage. The increasing sour cherry pulp concentration in yoghurt resulted in increasing pH and whey separation, whereas the values of the other parameters, total solid, fat, protein, ash, titratable acidity and viscosity decreased. During storage, total phenolic contents and antioxidant activity in yoghurts ranged from 20 to 81μg gallic acid equivalent per mg of sample and from 48% to 86%, respectively.
AtıfScopus48WoS44OpenAlex63İncele - Derleme MakaleYalnız künye2012Scopus SJRQ1Hydropower for sustainable energy development in Turkey: The small hydropower case of the Eastern Black Sea Region
Capik, Mehmet; Osman Ylmaz, Ali; Cavusoglu, Ibrahim
Turkey is a rich country from the point of variety and potential of renewable energy resources. Hydros, winds, biomass, solar and geothermal are important renewable and environmentally friendly sources for energy in Turkey. Turkey produces large amount of hydropower with a total gross hydropower potential of 433 TW h/yr, which is equal to 13.8% of the total hydropower potential of Europe. Technically useable potential is 216 TW h/yr and economic potential is 140 TW h/yr. The main aim of the present study is to investigate hydropower potential of Turkey and small hydropower plants in Eastern Black Sea Region for sustainable energy development in Turkey. The geography of Turkey especially, Eastern Black Sea Region supports and suitable the development of the small hydro plants to increase the energy generation and utilization of available water sources in Turkey. Besides, the paper deals with hydropower policies to meet ever increasing energy demand for sustainable development of Turkey.
AtıfScopus51WoS43OpenAlex54İncele - DüzeltmeYayıncıda açık erişim2012Scopus SJRQ1Erratum: Probabilistic sensitivity analysis of two suspension bridges in Istanbul, Turkey to near- and far-fault ground motion (Natural Hazards and Earth System Sciences (2012) 12 (459-473))
Çavdar, O.
No abstract available.
- MakaleYalnız künye2012Scopus SJRQ1Two-Dimensional Geothermal Modelling Along the Central Pontides Magmatic Arc: Implications for the Geodynamic Evolution of Northern Turkey
Maden, Nafiz
The Pontides, which can be divided tectonically into three main segments as Eastern, Central, and Western Pontides, is one of the most complex geodynamic settings within the Alpine belt. The Central Pontides, where the Eastern and Western Pontides met and formed a tectonic knot, represent an amalgamated tectonic mosaic consisting of remnants of oceanic, continental, and island arc segments. Subduction polarity, which is responsible for the formation of the Pontides, is still under debate because of limited geological, geophysical, and geochemical data. Two-dimensional (2-D) thermal modelling studies along the Central Pontides magmatic arc (Northern Turkey), Sakarya and Ki{dotless}rşehir continents are investigated in order to delineate the crustal thermal structure and subduction polarity. The obtained numerical results indicate that arc and back-arc regions are hot because of the cooling effects of a subducting plate. Moho temperatures in the investigated region are found between 992°C in the south (back-arc) and 415°C in the north (arc). Moreover, mantle heat flow values vary from 57.2 mWm -2 in the south (back-arc) to 34.7 mWm -2 in the north (arc). It is shown from this study that the Eurasia plate had moved from north to south under the Anatolia plate along the south Black Sea coast.
AtıfScopus10WoS13OpenAlex12İncele - MakaleYalnız künye2012Scopus SJRQ2Virtual point detector for HPGe detectors for 26.6-1332 keV photon energies by experiment and Monte Carlo simulation
Çelik, N.; Çevik, U.; Küçükömeroğlu, B.
Variation of virtual point detector (VPD) position inside HPGe detector as a function of source photon energy for the energy range from 26.6 to 1,332 keV was investigated. Although VPD concept was well established for HPGe detectors from 59.5 to 10 MeV, a new attempt was made to obtain VPD positions for photon energies below 59.5 keV. It was found that VPD position shows different functional behavior for the energy ranges 26.6-59.5 keV and 59.5-1,332 keV. The VPD position decreases with increasing energy for 26.6, 31.7, 36.4, and 37.3 keV and increases with the energy until it reaches a plateau. The functional behavior of VPD position for the energy range 26.6-59.5 keV was attributed to the dead layer thickness of the Ge crystal. Monte Carlo simulations were performed to investigate the behavior of VPD position with various dead layer thickness ranging from 100 to 800 μm. It was seen that VPD position increases with increasing energy for 31.7, 59.5, and 80.1 keV more significant at relatively lower energies, but constant for the energies 661-1,332 keV.
AtıfScopus4WoS3OpenAlex3İncele - MakaleYalnız künye2012Scopus SJRQ2Effect of detector collimation on the measured mass attenuation coefficients of some elements for 59.5-661.6 keV gamma-rays
Çelik, Necati; Çevik, Ugur; Çelik, Ahmet
Mass attenuation coefficients were determined experimentally for Sc, Ni and W for gamma energies of 59.5, 122, 276, 302, 356, 383 and 662 keV for different detector collimator diameters ranging from 2 to 10 mm. The aim was to investigate the quantitative analysis of detector collimator diameter effect on measured mass attenuation coefficients. It was found that measured mass attenuation coefficients decrease systematically with the increasing collimator diameter. The relative difference was found to be up to around 3% in some cases. The observed decrease in mass attenuation coefficients was attributed to the detection of elastic and inelastic scattered photons from the absorber. In elastic scattering process the photons change in direction but not in energy and get counted under the full energy peak if they reach the detector. In inelastic scattering however, both direction and energy of the scattered photons change. It was seen that most of the inelastic scattered photons also get counted by the detection system since they lose an amount of energy lower than the energy resolution of the detector. It is understood from the present results that it is essential to take into account the experimental geometry when reporting mass attenuation coefficients.
AtıfScopus10WoS11OpenAlex13İncele - MakaleYalnız künye2012Scopus SJRQ2Determination of water level effects on the dynamic characteristics of a prototype arch dam model using ambient vibration testing
Sevim, B.; Bayraktar, A.; Altunişik, A.C.; Adanur, S.; Akköse, M.
This study investigated the water level effects on the dynamic characteristics of a prototype arch dam model using ambient vibration testing were investigated. Achievement of this purpose involved construction of a prototype arch dam-reservoir-foundation model under laboratory. The dam body was constructed with 60 cm height. Ambient vibration tests on the arch dam estimated its natural frequencies, mode shapes and damping ratios for different water levels. In the ambient vibration tests, ambient excitations are provided from small impact effects and the responses of the arch dam are measured. It can be stated from the study that natural frequencies are not overly changed among 0-30 cm water levels; however they are increased for higher water levels. The difference between the first natural frequencies of the arch dam obtained from empty reservoir (H = 0 cm) and full reservoir (H = 60 cm) is about 20-25%.
AtıfScopus24WoS21OpenAlex29İncele - MakaleYalnız künye2012Scopus SJRQ1Wave energy potential along the south-east coasts of the Black Sea
Akpinar, Adem; Kömürcü, Murat Ihsan
This study aims to assess and characterize wave energy resource along the southeastern coasts of the Black Sea. For this purpose, wave energy potential was investigated at a total of 7 study points in this area. The potential for energy generation was assessed based on six-hourly data from a third generation wave model (SWAN) covering the period 1995-2009. The results were validated with buoy measurements and wave energy and power was calculated with the numerical hindcast data. For characterization of wave energy potential, average annual and seasonal variations of the wave power in this area was firstly investigated. Second, wave energy development indexes and the probabilities of exceedance of wave power at the study points were determined. Third, wave energy resource in different ranges of significant wave heights and zero-crossing periods were characterized. Finally, It was found that annual wave energy of all points except Sinop point, whose annual wave energy is 10 MWh/m, is approximately 6 MWh/m and the bulk of annual wave energy occurs for significant wave heights between 0.5 and 2 m and periods between 2 and 5 s.
AtıfScopus86WoS81OpenAlex87İncele - MakaleAçık Erişim2012Scopus SJRQ2Metabolic syndrome in collection and disposal of solid waste sector
Eker, Hasan Huseyin; Bayraktarli, Recep Yilmaz; Issever, Halim; Ulas, Tumer; Erelel, Mustafa; Eser, Ali; Ozdilli, Kuraat; Ozder, Aclan
Objectives: This study aims to assess the frequency and factors relevant to metabolic syndrome in workers employed in the collection and disposal of solid waste sector. Materials and Methods: This cross-sectional study was conducted in the major solid waste collecting and disposal company named ISTAC AS (Istanbul Environmental Protection and Waste Processing Corporation) in Istanbul, Turkey. All 715 male employees of the company were included in the study without sampling. The study was completed with 619 subjects. Since it was a small group, female workers were not taken into ac-count in the study. Metabolic syndrome frequency was investigated according to the NCEP-ATP III criteria including the levels of systolic and diastolic blood pressure, waist perimeter, HDL, triglyceride, fasting blood glucose values. Results: Metabolic syndrome was present in 40.9% of participating employees. Metabolic syndrome was more common in those working in the excavation field (54.0%), such as caterpillar operators (56.5%), and less common in employees working in administrative offices, such as office staff or managers, who were under 35 years old and who had been working for less than 10 years (p < 0.05). Employees working in work stations other than administrative offices had a 2.60 times higher risk compared to those working in administrative offices. Conclusions: Metabolic syndrome may be related to work sta-tion, job, age and period worked by the subjects.
AtıfScopus6WoS5OpenAlex27
İncele - MakaleAçık Erişim2012Scopus SJRQ3On the numerical solution of fractional parabolic partial differential equations with the dirichlet condition
Ashyralyev, Allaberen; Cakir, Zafer
The first and second order of accuracy stable difference schemes for the numerical solution of the mixed problem for the fractional parabolic equation are presented. Stability and almost coercive stability estimates for the solution of these difference schemes are obtained. A procedure of modified Gauss elimination method is used for solving these difference schemes in the case of one-dimensional fractional parabolic partial differential equations.
AtıfScopus17WoS13OpenAlex23İncele - MakaleYalnız künye2012Scopus SJRQ3Burnout and job satisfaction in surgical nurses and other ward nurses in a tertiary hospital: A comparative study in Turkey
Cilingir, Dilek; Gursoy, Ayla Akkas; Colak, Ayse
Aim: Job dissatisfaction and burnout have a negative effect on health care providers, especially nurses. This often results in a shortage of qualified personnel as well as a decrease in the quality and level of care provided to patients. This study carried out to describe the level of burnout and job satisfaction among surgical nurses and to compare them to nurses working in other wards in terms of these aspects. Methods: The study was designed as a cross-sectional and descriptive survey. The sample of the research consisted of 330 nurses working in a tertiary hospital in the northeastern part of Turkey. A questionnaire form, Minnesota Job Satisfaction Questionnaire and Maslach Burnout Inventory were used in order to collect the data. The student t test in independent variables, ANOVA, and Pearson's Correlation Coefficient were used in order to analyze the data. Results: Study results indicated that surgical nurses experienced emotional exhaustion more than pediatric nurses. They had higher levels of depersonalization than the policlinic and gynecological nurses. It was also found that nurses working in operating rooms and urology units experienced more emotional exhaustion than other surgical nurses. Conclusion: The study results showed that the state of emotional exhaustion and depersonalization of the surgical nurses was higher than the means of nurses working in other wards and job satisfaction and personal accomplisment were similar.
AtıfScopus6WoS6İncele - MakaleYalnız künye2012Scopus SJRQ2Complete versus partial mobilization of splenic flexure during laparoscopic low anterior resection for rectal tumors: A comparative study
Gezen, Cem; Altuntas, Yunus E.; Kement, Metin; Vural, Selahattin; Civil, Osman; Okkabaz, Nuri; Aksakal, Nihat; Oncel, Mustafa
Background: The aim of the current study is to compare the results after partial and complete splenic flexure mobilization (SFM). Subjects and Methods: The records of laparoscopic and hand-assisted laparoscopic procedures for primary rectal tumor patients were abstracted from a prospectively designed database. The phrenicocolic and splenocolic ligaments were divided via a four-trocar technique in the partial SFM group, and dissection was continued with the separation of gastrocolic and pancreaticomesocolic attachments via a five-trocar procedure in the complete SFM group. The following data were compared between the groups: Demographics, intra- and postoperative information, and pathological features. Results: In total, 122 cases (77 [63.1%] male, 58.2±13.2 years old) who underwent a partial (n=36, 29.5%) or a complete (n=86, 70.5%) SFM were included. Reservoir creation (48.8% versus 19.4%, P=.003) was more common and conversion (8.1% versus 22.2%, P=.039) was less frequent in the complete SFM group, but there were significantly more T4 tumors in the partial group (16.7% versus 2.3%, P=.008). Demographics, other intra- and postoperative parameters, and pathological features were identical. Conclusions: In our study, complete SFM decreased conversion rates, but this finding may be related to the higher rate of T4 tumors in the partial SFM group. Complete SFM assures an increase in reservoir creation in patients receiving a low anterior resection. Because other parameters are identical, the decision for the level of SFM is better left to the surgeon in cases undergoing a low anterior resection, but complete SFM may be preferred in cases who are candidates for a reservoir formation.
AtıfScopus22WoS17OpenAlex28İncele - MakaleAçık Erişim2012Scopus SJRQ2Finite difference method for the reverse parabolic problem
Ashyralyyev, Charyyar; Dural, Ayfer; Sozen, Yasar
A finite difference method for the approximate solution of the reverse multidimensional parabolic differential equation with a multipoint boundary condition and Dirichlet condition is applied. Stability, almost coercive stability, and coercive stability estimates for the solution of the first and second orders of accuracy difference schemes are obtained. The theoretical statements are supported by the numerical example.
AtıfScopus20WoS20OpenAlex17İncele - MakaleYalnız künye2012Scopus SJRQ2In vitro antifungal evaluation of various plant extracts against walnut anthracnose (Gnomonia leptostyla (Fr.) Ces et de Not.)
Kalkişim, Özgün
Antifungal activity of different parts (fruit and leaf) of Cornus mas L. (Cornecea), Morus nigra L. (Moraceae) and Prunus laurocerasus L. (Rosaceae) methanol extracts has been tested against walnut anthracnose. Agar dilution method has been used in antifungal activity studies. A standard fungicide (80% Maneb; Hektas Group) was used in order to compare the herbal extracts. The highest antifungal effect was observed in the leaf extracts of C. mas and M. nigra for which mycelium growth inhibition ratios observed were 67.95% and 60.04%, respectively. Different antifungal effect ratios have been determined for other plant extracts used. Also, the effect of Gnomonia leptostyla disease on walnut yield was examined for three different types of walnut trees. According to these results, it has been concluded that walnut anthracnose disease has an effect on the yield.
AtıfScopus10WoS7İncele - MakaleYalnız künye2012Scopus SJRQ2Laparoscopic and conventional resections for low rectal cancers: A retrospective analysis on perioperative outcomes, sphincter preservation, and oncological results
Gezen, Cem; Altuntas, Yunus E.; Kement, Metin; Aksakal, Nihat; Okkabaz, Nuri; Vural, Selahattin; Oncel, Mustafa
Background: This study aims to compare the results of laparoscopic and conventional techniques in patients with low rectal cancers. Subjects and Methods: A retrospective data analysis was initiated in patients underwent laparoscopic or conventional surgery for cancers located in the low (<6 cm) rectum. Patient and tumor-related information, outcomes of operations, and survival were compared between the groups. Results: Among 142 patietns (91 men [64.1%]; mean±standard deviation age, 57.7±14.6 years) who had tumors located <6 cm from the dentate line, 92 (64.8%) were operated on with the laparoscopic technique. Demographics, tumor stage, and localization (2.9±2.0 versus 2.9±2.1 cm from the dentate line in laparoscopic and conventional arms, respectively; P=.968) were similar. However, there were more patients in the laparoscopic group who received neoadjuvant chemoradiation therapy (92.4% versus 80.0%; P=.03), since there were significantly fewer cases with stage I tumors in this group (3.3% versus 14%; P=.33). The conversion rate was 14.1% (n=13). The amount of bleeding and the requirement for transfusion decreased (P<.05 for both), and the possibility of sphincter-saving procedures (66.3% versus 34.0%; P<.001) increased, in the laparoscopy group. Other parameters were identical. In the laparoscopy group, the number of harvested lymph nodes (10.2±5.4 versus 12.4±6.0; P=.025) and the rate of vascular invasion (27.5% versus 47.8%; P=.021) were less, and Kaplan-Meier analysis revealed an improved survival (P=.042), although the follow-up period was significantly shorter in this group (P<.001). Conclusions: Laparoscopic surgery for low rectal cancers may be technically feasible and oncologically safe. Laparoscopy may increase the possibility of sphincter preservation.
AtıfScopus10WoS6OpenAlex8İncele