Hakkari University
  • Hakkari, Hakkari University, Turkey
Recent publications
Battery energy storage systems (BESS) are essential for flexible and reliable grid performance as the number of renewable energy sources in grids rises. The operational life of the batteries in BESS should be taken into account for maximum cost savings, despite the fact that they are beneficial for economical grid operation. In this context, this paper present a new battery cycle counting perspective for energy management of grid-connected BESS. For this purpose battery’s one full charge–discharge cycle characteristic is compared with the operating battery charge–discharge cycle every time step. This comparison was explained mathematically and graphically in detail. The results are compared with the rain flow counting method which is the most popular cycle counting algorithm. Consequently, this cycle counting approach successfully counts the battery charge/discharge cycles and it has shown that has an advantage for BESSs due to being specifically developed just for batteries.
BESS are now preferred to provide ancillary services due to their advantages of cost reductions and rapid response times. Based on the criteria in the regulation for the electricity grid, an advanced power management control algorithm with the technical features to provide the grid frequency support specified in the regulation on the use of BESSs in ancillary services has been developed in this study and evaluated in various scenarios. A 2 MW/1 MWh installed power BESS is considered for frequency support control, which is one of the grid ancillary services. The algorithm is tested for providing the appropriate power by optimally using the state of charge of the battery within the limits specified in the regulation. Since the maximum and minimum set limits for the state of charge cannot be exactly defined in the literature, the fuzzy logic method was chosen as the decision-maker for active power output. In the algorithm, the amount of power that must be supplied by the battery energy storage system will change according to the dynamically varied state of charge. The results show that the fuzzy logic control algorithm successfully provides the frequency response in the regulation zone with optimum SOC level and contributes the extending the battery life.
The present study investigates the effect of carbon fiber hybridization and graphene nanoplatelets inclusion on the vibration damping properties of glass fiber reinforced polymer composites. The hand layup method was utilized with hot press molding in hybrid/non-hybrid composite plate production. A total of sixteen laminates, eight containing pure glass/epoxy and pure carbon/epoxy, and the remainder containing glass/carbon, were stacked in four different arrays and impregnated with an epoxy matrix to provide a hybrid/non-hybrid configuration. In the first hybrid configuration, the glass fiber fabric is on the outer surface and the carbon fiber fabric is on the inside of the composite plate; in the second configuration, the opposite of this sequence was used. Graphene Nanoplatelets (GNPs) were added into the epoxy resin in different weight fractions (0, 0.1, 0.25, and 0.5 wt%). Experimental modal analysis was performed to evaluate the natural frequency and damping ratios of the GNPs modified/unmodified test samples. According to the results obtained, carbon fiber hybridization not only increased the natural frequency but also caused a decrease in the damping ratio of the glass fiber reinforced composite material. On the other hand, incorporating 0.5% by weight of GNPs into the epoxy matrix improved damping ratios by approximately 42.1, 51.6, 16.7 and 17.2% for the G05, GC05, CG05 and C05 samples, respectively, compared to the pure samples. Also, a decrease in natural frequency and loss storage values were observed at high GNPs content.
A computational study of the radical-mediated chemoselective difunctionalization of the tertiary alcohol substituted aliphatic alkenes is carried out employing density functional theory (DFT) and high-level coupled-cluster methods, such as coupled-cluster singles and doubles with perturbative triples [DLPNO-CCSD(T)]. Our results indicate that the cyclic vinyl radical plays an important role in the progression of the reactions. Our computations demonstrated that the chemoselective difunctionalization of unactivated alkenes with radical-mediated remote functional group migration is suitable for the 5- and 6-exo-dig cyclization, as opposite to 3- and 4-exo-dig cyclization suffering from cyclic intermediate with high energy. Our results show that the migration of nitrile group is more preferable than that of alkynyl group for the molecules including both cyano group and alkynyl group. For the 5- and 6-exo-dig cyclization, the rate-determining step is the homolysis of the C-C σ-bond in the cyclic intermediate, which results in the hydroxyl alkyl radical.
Two spider species of the liocranid genus Mesiotelus Simon, 1897 new to the fauna of Turkey are recorded on the basis of female specimens: M. caucasicus Zamani et Marusik, 2021 from Hakkari Province in the Eastern Anatolia and M. deltshevi Naumova, 2020 from Diyarbakır Province in the Southeast Anatolia. The characteristic features are illustarted. In addition, M. scopensis Drensky, 1935 and M. tenuissimus (L. Koch, 1866), two other species found in Turkey, are illustrated. The distribution records of all of these species in Turkey are mapped. With these new records, the number of species belonging to the family Liocranidae in Turkey has increased to 18.
Background Forage pea (Pisum sativum var. arvense L.) is an important legume species with high nutritional value used in animal feed nutrition around the world. Forage pea have been grown for animal feeding in the high altitude of the Eastern Anatolia Region for a long time. However, commercial varieties of forage peas are replacing local varieties, especially due to easier seed availability. Therefore, it is aimed in this study is determine of genetic diversity and genome size variation of some forage pea commercial and landraces populations by SSR markers. Methods and results This study was carried out in 2021 with 18 populations in cultivated in Turkey. The 11 SSR markers successfully produced total 66 polymorphic bands by percentage of 89,2% for 18 forage pea (Pisum sativum var. arvense L.) populations. The markers produced a total of 66 alleles. These polymorphic alleles were ranged from 3 to 11 with average of 6. Conclusions Genetic diversity dendrogram was created forage pea cultivars populations. Generally, seven commercial cultivars and eleven populations of forage pea seperated each other as two main groups. As a result of the study, genetic differences were found between pea varieties, and it was concluded that local varieties should be evaluated in breeding programs.
Nanoparticles (NPs) of CaO (Ca 2+) are significant components that act as signal transductors in plants' adaptive and developmental processes. The responses of two different landrace varieties (Uzuntekne and Barış) of Onobrychis viciifolia to the mannitol stress of CaO NPs were investigated in this study. Their response to various morphological and physiological processes under in vitro conditions was analyzed in this study. Two Onobrychis viciifolia cultivars were used in the presence of 50 and 150 mM of mannitol, including 0.5 ppm and 1.5 ppm Ca 2+ nanoparticles. The effects of CaO NPs were induced by mannitol which, root, stem, leaf development, MDA, H 2 O 2 , chlorophyll content, gene expression, and SEM images were determined for the in vitro seedlings. CaO remarkably increased the activation of growth parameters in two tested cultivars. Synergistic treatments of NPs affected the seedlings more than the sole treatments. In terms of MDA, H 2 O 2 , and chlorophyll content, it was found that the Ca 2+ NPs treatment was significant, and it exhibited a high level related to the resistance degrees of cultivars. The chlorophyll content demonstrated a reducing trend in response to increasing concentrations of mannitol. However, there were significant differences between the control group samples and the CaO mannitol treatment samples in response to H 2 O 2 and MDA. The gene expression analysis revealed that MtdDehyd and MtRD2 genes were expressed at various degrees in the seedlings of two Onobyrchis cultivars subjected to drought treatments. Improving resistance to drought stress in tested cultivars can be regulated by expressing MtdDehyd and MtRD2 genes in vitro conditions. SEM images in stomatal structures of cells were easily changed in the mannitol treatment samples in the presence of CaO, and a different stress severity level was detected in their control treatments.
Natrix natrix (Linnaeus, 1758) is a common species distributed from Central Europe to Central Asia. In this range, it forms four subspecies that include several mitochondrial evolutionary lineages. One of the lineages, the so-called mtDNA lineage 8, has a wide distribution from the Baltic area to Anatolia and Kazakhstan. In Anatolia, this lineage meets several others, however, their occurrence is unclear, especially in southeastern Türkiye where the species is uncommon. Obtaining one specimen from the poorly studied Hakkâri Province (Zagros part of Türkiye), we investigated its genetic affiliation (mitochondrial DNA) and basic morphology. The specimen represents a unique haplotype of the mtDNA lineage 8, closely related to populations from Georgia and northern and northeastern Türkiye. It thus extends the occurrence of this mitochondrial lineage representing subspecies Natrix natrix scutata (Pallas, 1771) southward to the northern edge of the Zagros Mountains. Despite the phenotype polymorphism of this species, the morphological comparison also confirmed that selected characters are similar to other populations of the region.
Water hardness affects metal uptake and toxicity in fish. Calcium is the most important ion determining water hardness. Fish are one of the most important food supplies for humans. Thus, Oreochromis niloticus were exposed to Cr⁶⁺, Ni²⁺, Zn²⁺ and Hg²⁺ in differing Ca²⁺ levels (30, 60 and 120 mg Ca²⁺/L) and subsequently serum biochemical parameters and muscle food quality were investigated. In acute experiments (3 days), fish were exposed to 30 µM of Cr⁶⁺, Ni²⁺ and Zn²⁺, and 0.3 µM of Hg²⁺, though they were exposed to 10 µM for Cr⁶⁺, Ni²⁺ and Zn⁺² and 0.03 µM for Hg²⁺ in chronic experiments (30 days). Data showed that there were significant (p < 0.05) alterations in the levels of glucose, alanine transaminase, aspartate transaminase, cholesterol and triglyceride in the serum, most alterations being at the lowest calcium level. Serum ion levels (Na⁺, K⁺, Ca²⁺⁾ also altered significantly, but only in chronic exposures. There were significant variations in the quality of muscle in both durations, as total protein, lipid and raw ash levels altered significantly (p < 0.05), though no significant change occurred in the water content of muscle tissue. This work demonstrated that metals affected the serum biochemistry and muscle food quality of Oreochromis niloticus, emphasizing the stress that fish could face in metal-contaminated waters.
One of the most debated problems in the history of philosophy is the problem of evil. However, this issue is not only a problem of philosophy but also that of the religions which have a tradition of revelation. Religions such as Judaism, Christianity and Islam deal with this problem to some extent. Their instruments for answering this issue differ from philosophical explanations used the reasoning process intensely. Philosophers and theologians have tried to answer according to the religious tradition they belong to while offering some solutions to this problem. However, while giving these answers, they did not always take religious tradition into consideration, and they often tried to offer philosophical answers. In this paper, I tried to concentrate on some verses of the Qur'an that can be associated with the problem of evil and to show the relations between the concepts used in this context. Subsequently, I discussed whether some of the parables in the Qur’an can be evaluated within the framework of theodicy. Moreover, throughout this study, I tried to reveal the differences between the argument and style in the Qur'an and the philosophical theodicy also called systematic theodicy.
In this research, fresh green peppers were dried in a kitchen microwave oven at 600W, 700W and 800W. The drying curves of the study were compared with 5 different thin layer drying models in the literature. The changes in the moisture values of the samples against time were expressed graphically. R2, χ2 and RMSE values were used to determine the most suitable model for dried green peppers. Color values of fresh and dried peppers were determined. It was found that the L* and b* values of the dried peppers were lower, and the a* value was higher than the fresh green peppers. In addition, the rehydration rate of dried peppers was calculated. It was determined that the rehydration ability of the peppers decreased as the applied microwave power increased. For this reason, it was found that the peppers with the highest rehydration rate were those dried with 600W. Also, it was found that the most suitable model for all microwave powers among the five drying models was the Logarithmic drying model. It was calculated that the R2 values of the drying models ranged between 0.830-0.999, χ2 values between 0.0001- 0.4684 and RMSE values between 0.0014-0.6121. It was determined that the highest R2 (0.997-0.999), the lowest χ2 (0.0001-0.0002) values, and the lowest RMSE (0.0014-0.0035) values for all microwave powers belong to the Logarithmic drying model.
Since the effectiveness of pedagogies relies heavily on the context they are practiced, scholars strive to revalidate them with different participants representing different disciplines, age, cultures and so on. In this regard, this piece of work was undertaken so as to reveal the impact of a digital game-based learning environment on the achievement of secondary school participants in the topic of Internet literacy in Turkey. To this end, a three dimensional multi-user digital game-based learning environment through Active Worlds game engine was created. The static-group pre-test post-test design was adopted. We recruited 266 students attending 10th-grade at a public high school. The participants were block-randomized to the groups. The control group partook in a lecture-based learning environment for two weeks, whereas the experimental group learned with a digital game-based learning environment. The results ascertained that even though there were significant learning gains in control as well as experimental groups, no substantial significant difference was observed in the achievement across the groups. The results illustrated that the interaction of method and gender had no influence on the achievement. Particularities of the context of the study causing the results and study’s far-reaching implications were discussed.
We analyse the evolution of a generalized bosonic oscillator in the near horizon geometry of the BTZ black hole by analytically obtaining a solution of the associated Klein-Gordon equation. We show that it is possible to obtain relativistic frequency expression in closed-form for the system in question. Here, we observe that such a system decays in time without any real oscillation and the damped modes depend explicitly on the parameters of the oscillator coupling besides the parameters of the background geometry. This result allows us to analyse the influences of both oscillator coupling and spacetime parameters on the evolution of such a test field. Also, the results indicate that the spacetime background is stable under this perturbation field.
We investigate the interaction of a generalized vector boson oscillator with the near-horizon geometry of the BTZ black hole and try to determine the corresponding quasibound state frequencies. To do this, we seek an analytical solution of the relativistic vector boson equation, derived as an excited state of Zitterbewegung, with Cornell-type non-minimal coupling in the near-horizon geometry of the BTZ black hole. The vector boson equation includes a symmetric spinor of rank two and this allows to obtain an analytical solution of the corresponding equation. By imposing appropriate boundary conditions, we show that it is possible to arrive at a relativistic frequency ($\omega$) expression in the form of $\omega=\omega_{\mathcal{R}e}+\omega_{\mathcal{I}m}$. Our results show that real($\propto \omega_{\mathcal{R}e}$) and damped($\propto \frac{1}{|\omega_{\mathcal{I}m}|}$) oscillations depend on the parameters of the background geometry, coefficients of the non-minimal coupling and strength of the oscillator. This allows us to analyse the effects of both non-minimal coupling and spacetime parameters on the evolution of the considered vector field. We discuss the results in details and see also that the background is stable under the perturbation field in question.
The effect of piston bowl geometry on reducing soot emissions, improving combustion, and in-cylinder flow movements in a direct injection diesel engine was investigated. Standard combustion chamber (SCC) and newly modified combustion chamber (MCC) geometries were compared at the same compression ratio (17.5:1). Experimental analysis of diesel engines is expensive and time consuming, and therefore the Computational Fluid Dynamics program was used to analyze the combustion, flow and emission process. AVL Fire ESE Diesel software was used in the numerical study. The numerical work was compared with the experimental results, and it was validated. In addition, 10% biodiesel mixture (10% Sal seed oil methyl ester + 90% diesel fuel) and diesel fuel were used in the analysis. These fuels and two different bowl geometries were investigated at 2000 rpm and full load conditions. Thus, the effect of the used biodiesel fuel and the developed bowl geometry were investigated. Sal seed oil methyl ester was used as biodiesel fuel. The results show that higher turbulence velocity distribution, better mixture fraction values and lower soot formation distribution are obtained by directing the MCC type fuel according to SCC type. When the pressure, temperature and heat release in the combustion chamber are examined, the highest values were obtained with B10 blended fuel used at the SCC type combustion chamber. The maximum heat release rates are 8.72, 9.38, 8.21, and 9.30 J/° for SCCD100, SCCB10, MCCD100 and MCCB10 fuels, respectively.
Oviposition was observed in Galeodes hakkariensis Erdek 2021. Part of the developmental changes post-hatch were recorded, and the cuticular surfaces of egg and first post-embryos were surveyed with a scanning electron microscope. This species has oval-shaped eggs varying from 2 mm to 4 mm in diameter. The fine structure of the external morphology of post embryos in a solifuge is shown for the first time. The cuticular patterns and sensilla on opisthosoma and tarsal sensilla on each pedipalp and leg were described in post-embryos. The surface of each opisthosomal basiconic sensilla without the socket is covered with pores, likely functioning as chemoreceptors. Tarsal basiconic sensilla not in a socket and without pores on pedipalps and legs likely function as mechanoreceptors. The single slit sensillum on the tarsus of pedipalps functions as mechanoreceptors.
There is a rising necessity concerning low energy consumption and thermal comfort, thus, new systems combining displacement ventilation and radiant heating are becoming common as a research topic. The current paper covers free, mixed, and forced convection in an experimental chamber consisting of a radiant wall heating system and a baseboard level diffuser. Air temperature in the test room is adjusted using an air blower via a novel designed baseboard level slot diffuser along with a hydronic wall heating circuit. Simultaneously; an upward direction air jet is blown through the heated or the opposite wall under two scenarios. The ranges of air inlet velocity and temperature are selected to be between 0.25 and 12.5 m/s and 14-26 • C, correspondingly. The heat transfer characteristics pertaining to the heated wall are studied with respect to the influences of wall and air temperatures, air inlet velocities, and the location of the diffuser. To derive convective heat transfer coefficient correlations valid for mixed and forced types for a radiant heated wall, acquired data have been processed. The convective, radiative, and total heat transfer coefficient intervals of 3-14.1, 5.2-5.5, and 9.3-21.7 W/m 2 K have been obtained for the radiant heated wall coupled with airflows, correspondingly.
Solar energy is one of the most prominent renewable energy sources today and it can contribute to the energy market with accurate solar radiation estimation. This study proposes a new deep learning-based solar radiation forecasting model using solar radiation data (W/m²) obtained from a ground-based Meteorology measurement station in Hakkari, Turkey, and satellite images taken simultaneously from the European Meteorological Satellites Utilization Organization (EUMETSAT). The model based on convolutional neural networks (CNN) framework adequately extracts the features inherent in multilayer satellite images used as input and obtains more accurate prediction results than traditional models. The prediction performance of the fully-trained CNN model was evaluated using different error metrics such as mean square error (MSE), mean absolute error (MAE), root mean squared error (RMSE), normalized root mean squared error (nRMSE), and coefficient of determination (R²). The results show that the proposed model can accurately predict solar radiation without the need for any measuring device, by making successful meteorological inferences from satellite images with 0.015% MSE, 8.21% nRMSE and 99.8% R² ratios. Furthermore, the proposed model can be used to verify and calibrate global solar radiation measured from the ground within other locations around the world with similar geographic and climatological characteristics.
The temperature dependence of the electrical parameters of the Au/α-Al2O3/p-Si/Al heterojunction diode and the variation of these parameters with radiation were investigated. It has been determined that the lnI–V curves of the diode have non-linear plots and this is due to the inhomogeneity in the potential barrier. The ideality factor (n), barrier height (Φb) and series resistance (Rs) values of the diode were calculated depending on the temperature. It was determined that n and Rs values decrease and Φb values increase with the increase in temperature. The voltage coefficients and standard deviation values are calculated using the [(1/n) − 1] − 1/2kT and Φb − 1/2kT graphs of heterojunction diode. The value of Richardson constant was calculated as A* = 7.64 A/K² cm² using conventional Richardson plot of ln(I0/T²) against 1/T. In addition, the effects of different X-ray irradiation doses on the I–V characteristics of Au/Al2O3/p-Si/Al heterojunction were examined.
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216 members
Mehmet Sait Taylan
  • Institute of Science - Biology Department
Ömer Demir
  • Department of Computer Technologies
Mehmet Bulut
  • Mechanical Engineering
Mehmet Nuri Bodur
  • Civil Engineering, Geotechnical Division
Ekrem Yasar Akcay
  • Department of Political Science and International Relations
Merzan Mah. Küçük Sanayi Sitesi Arkası 433. Sok. , 3100, Hakkari, Hakkari University, Turkey
Head of institution
Prof. Dr. Omer Pakis (Rector)
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