Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Demir, Veysel(3)
- Sançar, Taylan(3)
- Zabci, Cengiz(3)
- Akyüz, H. Serdar(2)
- Danabas, Durali(2)
- Kurum, Hasan(2)
- Oksuztepe, Eyyup(2)
- Ural, Mesut(2)
- Yaman, Mehmet(2)
- Yazici, Muge(2)
- Abaci, Z. Tugba(1)
- Aksakal, B.(1)
- Aksu, Onder(1)
- Akyol, Sinem(1)
- Akyuz, H. Serdar(1)
- Alatas, Bilal(1)
- Arslan, Zikri(1)
- Arslanoglu-Isik, Hilal(1)
- Ates, Mehmet(1)
- Baldemir, A.(1)
- Baskonus, Haci Mehmet(1)
- Biryan, Fatih(1)
- Bogatu, Corneliu(1)
- Boztug, Ali(1)
- Boztug, Durmus(1)
- Camas, Mustafa(1)
- Can, Safak Seyhaneyildiz(1)
- Celik, E.(1)
- Celik, Fatih(1)
- Cooper, Alan F.(1)
- Demirbilek, Deniz(1)
- Demirci, B.(1)
- Demirelli, Kadir(1)
- Duran, Tuba Cakmak(1)
- Erdogan, M.(1)
- Erecevit, Pinar(1)
- Gul, Muhammet(1)
- Gumus, A. T.(1)
- Guneri, Ali Fuat(1)
- Gündogdu, Hande(1)
Yayınlar
- MakaleYalnız künye2023Scopus SJRQ1Spatial dispersion hot spots of contamination and human health risk assessments of PTEs in surface sediments of streams around porphyry copper mine, Iran
Ipek, Yeliz; Kocak, Berna; Moussavi-Harami, Reza; Zand-Moghadam, Hamed; Mahboubi, Asadollah; Tohidi, Mohammad Reza
This comprehensive research has been conducted to consider the distribution of PTEs in the surface sediments of a recently developed Dar-e-Allo copper mine in dependence on the potential ecological and human health risks. Field sampling was carried out discreetly at preselected sampling spots including the natural background, the streams around the mine, waste rock drainages, evaporative deposits, sediments containing Fe oxy-hydroxides and secondary phases. Distribution of target elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Se, and Zn) showed high levels of crustal elements. As regards, Fe, Al, and S are identified to exist as the most copious elements in the earth's crust, so have the major portion of potentially toxic elements (PTEs) in the sediment concentrations. Evaluating environmental indices reflected that in general, Cu, S, and Mo have a higher quota of contamination in sedimentary systems. the pollution load index (PLI), modified contamination degree (mCd), Contamination factor (C-f), Sediment potential index (SPI), Geo-accumulation index (I-geo) and Contamination degree (C-d) confirm that sedimentary systems of mining area are heavily contaminated by PTEs and were not found within the guideline acceptable values. The potential ecological risk index (PERI) displayed a high or severe risk level for Cu with a peak in green-blue sediments containing secondary minerals. The results of total carcinogenic risk (TCRs) show that As has high toxicity level and carries a risk of carcinogenicity among children and adults. The TCRs for Cd, Cr, Ni, and Pb with carcinogenic potential are found only in children and they are classified as the prime concern elements that have serious dangers to children's public health. The results of contamination source presumed that the sources of PTEs contamination were principally geogenic along with the anthropogenic sources in the study area. Therefore, the present study has highlighted the implication of human health risks of PTEs in sedimentary systems of copper mining, also will grant advice for prime stakeholders, including mine managers, Environmental Protection Agency, the government and public organizations in connection to protecting the environment, aquatic biota and consumer's health.
AtıfWoS9OpenAlex11
İncele - MakaleYalnız künye2021Scopus SJRQ2Palaeoseismic behaviour of strike-slip faults in slowly deforming regions: palaeoearthquakes and long-term slip history of the Ovacik Fault (eastern Turkey)
Yazici, Muge; Zabci, Cengiz; Natal'in, Boris A.; Sançar, Taylan; Akyuz, H. Serdar
The Ovacik Fault (OF) is one of the internal structures of the Anatolian Block, located close to its eastern boundary. Although it shows a very clear surface trace, there are no instrumentally recorded surface rupturing earthquakes on this fault. This study concludes results of the first palaeoseismological trench study on the OF with the evidence for three surface rupturing earthquakes for the last 6 kyr. Structural, stratigraphical and geochronological constraints show that the oldest event happened between 4700 and 3022 BCE, whereas the penultimate event was between 2262 and 1643 BCE. The youngest event happened after 56 BCE, which we could only delimit from below because of the absence of any dateable material from the upper layers of the relevant horizons. The derived mean interevent time of these three palaeoevents is 2400 +/- 765 years. We could not correlate any of these palaeoevents with historical earthquakes due to the absence of records in catalogues for the region of interest. Moreover, we used cumulative offsets of the major drainages to calculate the long-term slip rate of 2.7 mm/year since the Pliocene, which exceeds slip rates of other internal faults of Anatolia almost by the factor of two. Our results do not only show significant deformation for the internal parts of Anatolia but also point out a seismic potential of the OF.
AtıfWoS5OpenAlex5İncele - MakaleYalnız künye2019Scopus SJRQ2Geometry and Paleoseismology of the Malatya Fault (Malatya-Ovack Fault Zone), Eastern Turkey: Implications for intraplate deformation of the Anatolian Scholle
Sançar, Taylan; Zabci, Cengiz; Karabacak, Volkan; Yazici, Muge; Akyüz, H. Serdar
The sinistral Malatya-Ovack Fault Zone (MOFZ) is one of the outstanding intraplate deformation belts within Anatolia. The 165-km-long, NE-SW-striking Malatya Fault (MF), which constitutes the southern section of the MOFZ, is separated into five segments according to its surface geometry. These segments have evident morphotectonic features that reflect long- and short-term fault activity, such as morphologic structures offset by as little as 7m and as much as 7.3km. This study provides results from the first paleoseismological investigations on the MF. We find that the last earthquake occurred between 965 and 549 BCE and calculate a recurrence interval of 2275 +/- 605years from evidence for four paleo-events over the last 10ka. Considering fault segmentation and our paleoseismological data, we propose that the accumulated strain on the MF may cause a destructive earthquake (M=7.4) in the near future. Our results support the hypotheses that the MF and other NW-striking dextral and NE-striking sinistral strike-slip faults within the eastern part of Anatolia are plate boundary-related, active deformational structures.
AtıfWoS19OpenAlex29İncele - MakaleAçık Erişim2017Scopus SJRQ1Plant intelligence based metaheuristic optimization algorithms
Akyol, Sinem; Alatas, Bilal
Classical optimization algorithms are insufficient in large scale combinatorial problems and in nonlinear problems. Hence, metaheuristic optimization algorithms have been proposed. General purpose metaheuristic methods are evaluated in nine different groups: biology-based, physics-based, social-based, music-based, chemical-based, sport-based, mathematics-based, swarm-based, and hybrid methods which are combinations of these. Studies on plants in recent years have showed that plants exhibit intelligent behaviors. Accordingly, it is thought that plants have nervous system. In this work, all of the algorithms and applications about plant intelligence have been firstly collected and searched. Information is given about plant intelligence algorithms such as Flower Pollination Algorithm, Invasive Weed Optimization, Paddy Field Algorithm, Root Mass Optimization Algorithm, Artificial Plant Optimization Algorithm, Sapling Growing up Algorithm, Photosynthetic Algorithm, Plant Growth Optimization, Root Growth Algorithm, Strawberry Algorithm as Plant Propagation Algorithm, Runner Root Algorithm, Path Planning Algorithm, and Rooted Tree Optimization.
AtıfWoS188OpenAlex218İncele - MakaleYalnız künye2017Scopus SJRQ2Palaeoseismic history of the eastern part of the North Anatolian Fault (Erzincan, Turkey): Implications for the seismicity of the Yedisu seismic gap
Zabci, Cengiz; Akyüz, H. Serdar; Sançar, Taylan
The North Anatolian Fault showed a remarkable seismic activity especially between 1939 and 1999, when the westward migrating earthquake sequence created surface ruptures more than 1000 km, leaving unbroken only the Marmara segments, to the west, and the Yedisu Segment, to the east along the main strand of the fault. To understand the palaeoseismicity of the Yedisu Seismic Gap, we undertook trench investigations close to the village of Balaban SarA +/- kaya, on the western part of the Yedisu Segment. We found evidence for at least five surface faulting earthquakes, from which only two are correlated with the 18 July 1784 CE and 27 June 1583 CE historical events. Although the surface rupture of the 1784 CE was reported by other trench studies, the evidence of 1583 CE event is presented for the first time. In consideration with other historical earthquakes, affecting the region east of Erzincan, we suggest that this particular section of the North Anatolian Fault may be in a seismically quiescent period, following a cluster of earthquakes in its near history. In order to test this hypothesis, further studies are needed to increase our knowledge on the temporal and spatial seismic behaviour of the Yedisu Segment, which has potential to create an earthquake with M (w) similar to 7.2 in the near future.
AtıfWoS15OpenAlex23İncele - MakaleAçık Erişim2017Scopus SJRQ2Synthesis, thermal degradation and dielectric properties of poly[2-hydroxy,3-(1-naphthyloxy)propyl methacrylate]
Biryan, Fatih; Demirelli, Kadir; Torgut, Gulben; Pihtili, Guzin
2-Hydroxy-3-(1-naphthyloxy)propyl methacrylate (NOPMA) monomer was synthesized from reaction of 2-[(2-naphthyloxy)methyl]oxirane with methacrylic acid in the presence of pyridine. The polymerization of NOPMA was carried out by free radical polymerization method in the presence of AIBN at 60 A degrees C. The structure of monomer and polymer was characterized by H-1-NMR, C-13-NMR and FT-IR spectroscopy techniques. The glass transition temperature and average-molecular weights of poly(NOPMA) were measured using differential scanning calorimetry and gel permeation chromatography, respectively. The thermal degradation behavior of poly(NOPMA) has been investigated by FT-IR studies of the partially degraded polymer and thermogravimetry. The cold ring fractions (CRFs) were collected at two different temperatures, initially fraction-1 (CRF1) is from room temperature to 320 A degrees C, and the other fraction-2 (CRF2) is from 320 to 500 A degrees C. The volatile products of the degradation were trapped at -195 A degrees C (in liquid nitrogen). All the fractions were characterized by FT-IR, H-1 and C-13-NMR spectroscopic techniques, and the cold ring fractions (CRFs) were also characterized by GC-MS. For the degradation of polymer, the major compound between products of CRFs is alpha-naphthol. The GC-MS, FT-IR and NMR data showed that depolymerization corresponding to monomer was not prominent below 320 A degrees C in the thermal degradation of poly(NOPMA). The mode of thermal degradation containing formation of the major products was identified. The dielectric permittivity (epsilon'), the loss factor (epsilon aEuro(3)) and conductivity (sigma(ac)) were measured using a dielectric analyzer in the frequency range of 50 Hz to 20 kHz.
AtıfWoS17OpenAlex22İncele - MakaleYalnız künye2016Scopus SJRQ1New acoustic wave behaviors to the Davey-Stewartson equation with power-law nonlinearity arising in fluid dynamics
Baskonus, Haci Mehmet
This manuscript investigates the new acoustic wave behaviors of the Davey-Stewartson equation with power-law nonlinearity with the help of sine-Gordon expansion method. This technique yields many new acoustic wave behaviors such as hyperbolic, exponential and complex function structures to the problem considered. Wolfram Mathematica 9 has been used throughout the paper for mathematical calculations along with obtaining two-and three-dimensional surfaces of results.
AtıfWoS142OpenAlex156İncele - MakaleYalnız künye2016Scopus SJRQ3Essential Oil Composition of Scaligeria napiformis Native to Turkey
Baldemir, A.; Demirci, B.; Ilgun, S.; Kosar, M.; Paksoy, M. Y.
AtıfWoS3OpenAlex2İncele - MakaleAçık Erişim2016Scopus SJRQ2An extended fuzzy TOPSIS-GRA method based on different separation measures for green logistics service provider selection
Celik, E.; Erdogan, M.; Gumus, A. T.
In this paper, first, the criteria that make logistics service providers more green'' are determined as: cooperation with customer's company and its customer, green government regulations, environmental management system, green process design, reduction in energy consumption and green network design. The criteria weights are determined by fuzzy AHP, based on expert opinions. Then, a new method is proposed, which is the combination of fuzzy TOPSIS and GRA, and used to evaluate green 3PLs based on different separation measures, as an extension, using trapezoidal fuzzy numbers. Five Turkish 3PLs serve in Istanbul are selected in order to apply a case study to show the applicability of the proposed method. Finally, the proposed method is verified with respect to different resolving coefficient values and separation measures and also compared with fuzzy TOPSIS and fuzzy VIKOR method results. Different multi-criteria decision-making methods can be applied and compared to check validity of our results for future studies. The proposed method can also be implemented to 3PLs in other countries.
AtıfWoS47OpenAlex57İncele - MakaleYalnız künye2016Scopus SJRQ2Effects of hydroxyapatite/Zr and bioglass/Zr coatings on morphology and corrosion behaviour of Rex-734 alloy
Say, Y.; Aksakal, B.
To improve corrosion resistance of metallic implant surfaces, Rex-734 alloy was coated with two different bio-ceramics; single-Hydroxyapatite (HA), double-HA/Zirconia(Zr) and double-Bioglass (BG)/Zr by using sol-gel method. Porous surface morphologies at low crack density were obtained after coating and sintering processes. Corrosion characteristics of coatings were determined by Open circuit potential and Potentiodynamic polarization measurements during corrosion tests. Hardness and adhesion strength of coating layers were measured and their surface morphologies before and after corrosion were characterized by scanning electron microscope (SEM), XRD and EDX. Through the SEM analysis, it was observed that corrosion caused degradation and sphere-like formations appeared with dimples on the coated surfaces. The coated substrates that exhibit high crack density, the corrosion was more effective by disturbing and transmitting through the coating layer, produced CrO3 and Cr3O8 oxide formation. It was found that the addition of Zr provided an increase in adhesion strength and corrosion resistance of the coatings. However, BG/Zr coatings had lower adhesion strength than the HA/Zr coatings, but showed higher corrosion resistance.
AtıfWoS18OpenAlex19İncele - MakaleAçık Erişim2016Scopus SJRQ3Switched reluctance motor control without position sensor by using data obtained from finite element method in artificial neural network
Polat, Mehmet; Oksuztepe, Eyyup; Kurum, Hasan
Switched reluctance motors (SRMs) require sensitive rotor information in order to work sensitively and properly and especially for the commutation of phase currents. Position information is generally acquired from a sensor which is generally placed into the stator or connected to the rotor. However, sensors have disadvantages in terms of cost, safety, complexity and volume. In order to remove these disadvantages, recent studies concentrate on SRMs working without a position sensor. In this study control methods working without a position sensor are examined, the applied method is presented comprehensively. The education and test data of the artificial neural network is not obtained from simulation or experimental results; it is obtained from magnetic analyses carried out in ANSYS 10 and the results are used in position speed and current sensorless control of SRM. The validity of proposed method is demonstrated by using DS 1103.
AtıfWoS8OpenAlex11İncele - MakaleYalnız künye2016Scopus SJRQ1An artificial neural network-based earthquake casualty estimation model for Istanbul city
Gul, Muhammet; Guneri, Ali Fuat
Earthquakes over the world cause serious damages for people and the economy. The establishment of an appropriate model to estimate potential losses or injuries in earthquake disasters is fundamental to decrease their impacts and losses and effectively respond and mitigate. Turkey as a country that experienced many earthquakes in the last century and had serious human and financial losses needs a comprehensive knowledge of consequences of devastating earthquakes to be able to plan for the future. Artificial neural networks (ANNs) have abilities to solve and analyse complex relations as an appropriate method to estimate number of injuries. In this study, an ANN model is built up for the earthquake casualty prediction, which takes earthquake occurrence time, earthquake magnitude, and population density as the predictors and employs 21 Mw > 5 earthquake disasters occurred in Turkey from 1975 as samples for the training of the network. The model was then tested on a study region consisting of four districts in Istanbul which is estimated to have the highest injury rate according to the earlier reports and generated estimations of the expected number of injured people. Results show that 99.9 % of the variability in the number of injured people is predictable with using this ANN model. Comparison of actual values and estimated output values in the ANN model was also found apparently very close to each other. According to the test case study results, when the value of earthquake magnitude is 6.5 Mw, number of injured people has increased in a sharp trend compared to the previous magnitude value (6 Mw) for all districts. Estimated number of injured people in daytime is obtained higher than at night when the earthquake magnitude is 5 and 5.5 Mw. The highest value in estimated number of injured people has emerged in Fatih district as 7241 for a 7.5 Mw daytime earthquake. On conclusion, it was deduced that the model can reveal accurate estimation of casualties and it can provide information in order to develop mitigation policies, especially in earthquake emergency service management.
AtıfWoS32OpenAlex46İncele - MakaleÖn baskısı açık2016Scopus SJRQ1Determination of anthocyanins in cherry and cranberry by high-performance liquid chromatography-electrospray ionization-mass spectrometry
Karaaslan, Nagihan M.; Yaman, Mehmet
Anthocyanins are a group of widespread natural phenolic compounds in vegetables and fruits. The anthocyanins have a wide range of applications due to the antioxidant, anticancer and anti-inflammatory properties. In this study, anthocyanins (delphinidin-3-o-glucoside, cyanidin-3-o-glucoside, pelargonidin-3-o-glucoside and malvidin-3-o-glucoside) in cherry and cranberry were determined using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). The anthocyanins were separated using gradient elution and a reserved-phase analytical column before identification by high-performance liquid chromatography-electrospray ionization-mass spectrometry. A high-performance liquid chromatography-electrospray ionization-mass spectrometry method was optimized for the determination of anthocyanins in cherry and cranberry. Furthermore, in this study, we investigated extraction conditions of fruit samples as well as determination of optimum HPLC-ESI-MS conditions. This study is novel in terms of simultaneously examining both optimization of HPLC parameters and extraction conditions. Obtained optimum conditions were used for the determination as the quantitative and qualitative analysis of anthocyanins in cherry and cranberry. The content of anthocyanins on the basis of wet weight in cherry and cranberry samples was determined for delphinidin-3-o-glucoside < d.l. (detection limit) and < d.l., for cyanidin-3-o-glucoside varied from 3.5 +/- A 0.4 to 8.3 +/- A 1.1 mg kg(-1) (average 5.8 +/- A 0.8 mg kg(-1)) and 9.8 +/- A 1.4 to 18 +/- A 3.0 mg kg(-1) (average 13.2 +/- A 1.8 mg kg(-1)), for pelargonidin-3-o-glucoside < d.l. and varied from 136 +/- A 19 to 233 +/- A 35 mg kg(-1) (average 185.3 +/- A 28 mg kg(-1)), for malvidin-3-o-glucoside < d.l. and < d.l., respectively.
AtıfWoS25OpenAlex29İncele - MakaleYalnız künye2015Scopus SJRQ2Removal of Phosphate from Aqueous Solutions by Chemical- and Thermal-Modified Bentonite Clay
Tanyol, Mehtap; Yonten, Vahap; Demir, Veysel
The study investigated phosphate adsorption from aqueous solutions using chemical- and thermal-modified bentonite in batch system. The adsorbent was characterized by SEM, BET, and FTIR spectroscopy. Contact time, beginning phosphate concentration, pH of the solution, and the effects of the temperature on phosphate adsorption capacity were determined by a series of experimental studies. In a wide pH range (3-10), high phosphate removal yields were obtained (between 94.23 and 92.26 %), and with the increase in temperature (from 25 to 45 degrees C), phosphate removal increased. Langmuir and Freundlich isotherms were used to determine the sorption equilibrium, and the results demonstrated that equilibriumdata displayed better adjustment to Langmuir isotherm than the Freundlich isotherm. Phosphate sorption capacity, calculated using Langmuir equation, is 20.37 mg g(-1) at 45 degrees C temperature and pH 3. Mass transfer and kinetic models were applied to empirical findings to determine the mechanism of adsorption and the potential steps that control the reaction rate. Both external mass transfer and intra-particle diffusion played a significant role on the adsorption mechanism of phosphate, and adsorption kinetics followed the pseudo-second-order-type kinetic. Furthermore, thermodynamic parameters (Delta H degrees, Delta G degrees, Delta S degrees) which reveal that phosphate adsorption occur spontaneously and in endothermic nature were determined. The results of this study support that bentonite, which is found abundant in nature and modified as an inexpensive and effective adsorbent, could be used for phosphate removal from aqueous solutions.
AtıfWoS26OpenAlex27İncele - MakaleAçık Erişim2015Scopus SJRQ2Influence of Alpha and Gamma-Iron Oxide Nanoparticles on Marine Microalgae Species
Demir, Veysel; Ates, Mehmet; Arslan, Zikri; Camas, Mustafa; Celik, Fatih; Bogatu, Corneliu; Can, Safak Seyhaneyildiz
The effects of alpha-iron oxide (alpha-Fe2O3) and gamma-iron oxide (gamma-Fe2O3) nanoparticles (NPs) on marine microalgae species (Nannochloropsis sp. and Isochrysis sp.) were investigated in this study. Both Fe2O3 NPs covered the surface of algae with the agglomerates of the nanoparticles. This form of physical NP toxicity significantly decreased the sizes of phytoplankton. Both NPs were toxic to the tested algal species, while alpha-Fe2O3 showed less toxicity than gamma-Fe2O3 NPs for both algal species. A comparative analysis of growth data of the two algal species treated with alpha-Fe2O3 or gamma-Fe2O3 NPs revealed that Isochrysis sp. are more sensitive than Nannochloropsis sp. Toxicity of these widely used NPs to primary producers forming the base of the food chain in aquatic environments might result in widespread adverse effects on aquatic environmental health.
AtıfWoS43OpenAlex45İncele - MakaleYalnız künye2014Scopus SJRQ1Ecological risk assessment of heavy metals in surface sediments of northern littoral zone of Lake Cildir, Ardahan, Turkey
Kükrer, Serkan; Seker, Sebahat; Abaci, Z. Tugba; Kutlu, Banu
In this paper, the heavy metal levels (Cu, Pb, Zn, Ni, Mn, Fe, As, Cd, Cr, Hg), organic carbon, and chlorophyll degradation products were studied to prove their ecological effects in Lake CA +/- ldA +/- r, where fossil fuels are used as an energy source in the studied area for most of the year, and domestic waste from settlements is discharged directly into the lake. Sediment samples were collected from six sites on the northern shore of CA +/- ldA +/- r Lake, Turkey in November 2012. Enrichment (EF) and contamination factor (CF) values were determined, and Pollution Load (PLI) and Potential Ecological Risk (PER) indices were calculated. Average concentrations of heavy metals in the sediments were, in descending order, Fe > Mn > Zn > Ni > Cr > Cu > Pb > As > Cd > Hg, respectively. According to mean values, the source of these elements may be considered natural due to lack of enrichment in Cu, Pb, Zn, Ni, and Cr in the sediment samples. Regarding enrichment of As, Cd, Mn, and Hg, the highest EF belongs to Hg. PLI and PER values indicate there are moderate ecological risk in the lake.
AtıfWoS97OpenAlex102İncele - MakaleÖn baskısı açık2014Scopus SJRQ3Sensorless vector control of PMSM with non-sinusoidal flux using observer based on FEM
Oksuztepe, Eyyup; Omac, Zeki; Kurum, Hasan
Back electromotive force method has been widely used in the position and speed sensorless control of permanent magnet synchronous motors. In this method, it is supposed that the back electromotive forces induced on the stator windings by the rotor permanent magnets are sinusoidal. This assumption causes errors in the estimation of speed and position. In this paper, an observer using the stator winding linkage flux model obtained by using finite element method for position and speed sensorless field-oriented control of permanent magnet motor is proposed. The validity of the proposed method is demonstrated using DS 1104.
AtıfWoS11OpenAlex12İncele - MakaleYalnız künye2014Scopus SJRQ4NMR Proton Spin-Lattice Relaxation Mechanism in D2O Solutions of Albumin Determined at 400 MHz
Yilmaz, A.; Zengin, B.; Ulak, F. Sadan
T-1 values in pure D2O and D2O solutions of human serum albumin (HSA) were measured versus temperature. A formula was derived based on H-H interactions between the surface HDO and non-exchangeable protein protons. The formula was used to evaluate the average distance of the interactions (rav). The effective correlation times were then derived by replacing the experimental data in the formula. Short correlation times obtained for the solution with low HSA (0.02 g albumin for one ml of D2O) decreased from 53 to 29 ps, while longer times increased from 1.19 to 2.22 ns. They are of the order of a fraction of a nanosecond for the solution with high HSA (0.08 g albumin per one ml of D2O). The perfect consistency between the derived theory and experimental data indicates that the high-field 1/T-1 in D2O solutions of albumin is caused by dipolar interactions between the surface HDO and non-exchangeable protein protons. It also suggests that the effective correlation time of the surface HDO is of the order of the mean lifetime of short-lived surface water.
AtıfWoS9OpenAlex12İncele - MakaleYalnız künye2013Scopus SJRQ2Amine-modified maleic anhydride containing terpolymers for the adsorption of uranyl ion in aqueous solutions
Simsek, Selcuk; Yilmaz, Ersen; Boztug, Ali
Maleic anhydride-styrene-methyl methacrylate (MA-S-MM) terpolymer was prepared. It was modified by ethylenediamine (EDA) and diethylenetriamine (DETA) in order to get cross-linked polymers bearing carboxyl and amine groups. Modified polymers used as an adsorbent for the removal of UO2 (2+) from water. The characterizations of structures of all the polymers were performed by Fourier transform infrared. The adsorptive features of adsorbents were then investigated for UO2 (2+) in view of dependency on ion concentration, pH, temperature and kinetics. Experimentally obtained isotherms were evaluated with reference to Langmuir, Freundlich and Dubinin-Radushkevich models. The maximum monolayer adsorption capacity for UO2 (2+) was found to be 1.59 and 2.43 mol kg(-1) for EDA-MA-S-MM and DETA-MA-S-MM, respectively. It can be said that the new modified polymers prepared in our laboratory have been suggested as new adsorbents for uranyl ions.
AtıfWoS27İncele - MakaleAçık Erişim2013Scopus SJRQ2Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates
Demirbilek, Deniz; Önal, Ayten Oztufekci; Demir, Veysel; Uslu, Gulsad; Arslanoglu-Isik, Hilal
Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD5/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.
AtıfWoS23OpenAlex21İncele