Exact solution of some nonlinear differential equations by Hirota method

Thesis (Master)--Izmir Institute of Technology, Mathematics, Izmir, 2005Includes bibliographical references (leaves: 45-47)Text in English; Abstract: Turkish and Englishix,60 leavesThe Hirota Bilinear Method is applied to construct exact analytical one solitary wave solutions of some class of nonlinear differential equations. first one the system of multidimensional nonlinear wave equation with the reaction part in form of the third order polynomial determined by three distinct constant vectors. Second one is the mixed diffusion wave equation in one dimension. The bilinear representation is derived by extracting one of the vector roots (unstable in general). This allows us reduce the cubic nonlinearity to a quadratic one. In our approach, the velocity of solitary wave is xed by truncating the Hirota perturbation expansion and it is found in terms of all three roots. Furthermore, Hirota Bilinear Method is also proposed to solve Brusselator reaction model. The simulations of solutions are illustrated for diffusion wave equation in one dimension. The bilinear representation is derived by extracting one of the vector roots (unstable in general). This allows us reduce the cubic nonlinearity to a quadratic one. In our approach, the velocity of solitary wave is xed by truncating the Hirota perturbation expansion and it is found in terms of all three roots.Furthermore, Hirota Bilinear Method is also proposed to solve Brusselator reaction model.The simulations of solutions are illustrated for different polynomial roots and parameters as well

Tuning of the electronic and optical properties of single layer black phosphorus by strain

Using first principles calculations we showed that the electronic and optical properties of single layer black phosphorus (BP) depend strongly on the applied strain. Due to the strong anisotropic atomic structure of BP, its electronic conductivity and optical response are sensitive to the magnitude and the orientation of the applied strain. We found that the inclusion of many body effects is essential for the correct description of the electronic properties of monolayer BP; for example while the electronic gap of strainless BP is found to be 0.90 eV by using semilocal functionals, it becomes 2.31 eV when many-body effects are taken into account within the G0W0 scheme. Applied tensile strain was shown to significantly enhances electron transport along zigzag direction of BP. Furthermore, biaxial strain is able to tune the optical band gap of monolayer BP from 0.38 eV (at -8% strain) to 2.07 eV (at 5.5%). The exciton binding energy is also sensitive to the magnitude of the applied strain. It is found to be 0.40 eV for compressive biaxial strain of -8%, and it becomes 0.83 eV for tensile strain of 4%. Our calculations demonstrate that the optical response of BP can be significantly tuned using strain engineering which appears as a promising way to design novel photovoltaic devices that capture a broad range of solar spectrum

A Case of Juvenile Ankylosing Spondylitis associated with Familial Mediterranean Fever

An eight year old male who was detected to have homozygous M694V mutation in the examinations for recurrent abdominal pain and familial history of Familial Mediterranean Fever (FMF) and who was then diagnosed with Juvenile Ankylosing Spondilitis (JAS) upon examination for hip joint pain was presented. This case was presented to emphasize the importance of high suspicion for JAS in FMF cases with atypical joint findings

Diet and wild ungulate preferences of wolves in northwestern Anatolia during winter

The gray wolf (Canis lupus) is making a comeback in many habitats in central Europe, where it has been once extirpated. Although densities are still low to moderate, this comeback already raises management concerns. In Anatolia, the gray wolf is one of the most common predator species occupying almost all kind of habitats. Although its numbers were reduced in some parts of the country, it has never been extirpated and lived in sympatry with humans. In this study we investigated, for the first time, the winter diet of wolves in north-west Anatolia, where a multispecies wild ungulate community occurs in sympatry with high density livestock. We selected two geographically close but different habitats (steppe and forest) with different wild prey availabilities and compositions. In both areas ungulate contribution to winter diet biomass was more than 90%. Wolf pack size (four to eight wolves) were higher in the study area where livestock numbers and human disturbance were lower and wild prey were more available. In both study areas, wild boar (Sus scrofa) was the main and most preferred food item (Chesson’s α = 0.7 − 0.9) and it occurred at higher density where wolf pack size was smaller. We could not find a high preference (Chesson’s α = 0.3) and high winter predation pressure on the reintroduced Anatolian wild sheep (Ovis gmelinii anatolica) population that occurs in the study area covered by steppe vegetation. Contribution of livestock and food categories other than wild ungulates to wolf diet stayed low. Wolves can help mitigate human-wildlife conflict regulating wild boar numbers, the most common conflict-causing ungulate species in Anatolia. Instead of managing wolf numbers in human dominated landscapes, we recommend reintroduction of wild ungulates to the areas where they became locally extinct and replaced by livestock

A New Efficient Technique for Solving Modified Chua's Circuit Model with a New Fractional Operator

Chua's circuit is an electronic circuit that exhibits nonlinear dynamics. In this paper, a new model for Chua's circuit is obtained by transforming the classical model of Chua's circuit into novel forms of various fractional derivatives. The new obtained system is then named fractional Chua's circuit model. The modified system is then analyzed by the optimal perturbation iteration method. Illustrations are given to show the applicability of the algorithms, and effective graphics are sketched for comparison purposes of the newly introduced fractional operatorsThe authors are grateful to the Spanish Government for Grant RTI2018-094336-B-I00 (MCIU/AEI/FEDER, UE) and to the Basque Government for Grant IT1207-1

New Record of the Velvet Belly Lanternshark Etmopterus spinax (Linnaeus, 1758) in the Deep Seas of Northern Cyprus

Lantern sharks are small shark species that can be seen at depths between 70 and 2000 meters.  Due to their luminescent characteristics, they have been called “Lantern shark”. In total eleven specimens of the velvet belly lantern shark, Etmopterus spinax (Linnaeus, 1758), were caught in the deep seas of Northern Cyprus by using a bottom trawl. Sampling was carried out using 13 trawling operations. The collected samples were placed in 4% formalin and stored at  the Museum of the Systematic, Faculty of Fisheries, Mersin University, (catalogue number: MEUFC-18-11-082). As a sampling area, the depths between 274 and 641 m were selected. Other cartilaginous fish caught during sampling except E. spinax were Galeus melastomus (1 individual), Squalus acanthias (4 individuals), Scyliorhinus canicula (85 individuals). E. spinax made up 10.89% of all cartilaginous fishes which were caught. Species identification for all fishes caught is made with the help of morphological features

Long term absolute sea level changes by tide gauge and continuous GPS data

Norveç kıyılarındaki ANDENES ve TREGDE mareograf istasyonlarındaki uzun dönemli mutlak deniz seviyesi değişimleri mareograf ve Sabit GPS zaman serilerinin analizi ile araştırılmıştır. Aylık ortalama deniz seviyesi ile Sabit GPS yükseklik zaman serilerindeki periyodik sinyallerin konumsal ve zamansal karakteri Deneysel Ortogonal Fonksiyon ve spektral analiz yöntemleri kullanılarak belirlenmiştir. Hem mareograf hem de Sabit GPS yükseklik zaman serisi doğrusal trendleri En Küçük Karelerle harmonik analiz yöntemiyle hesaplanmıştır. TREGDE’de anlamlı bir deniz seviyesi trendi bulunmazken, ANDENES mareograf istasyonunda uzun dönemli mutlak deniz seviyesinin 2.44 ± 0.21 mm/yıl hızla yükseldiği belirlenmiştir. Bu değer literatürdeki 1-3 mm/yıl düzeyindeki global deniz seviyesi değişimleri ile uyumludur.Anahtar Kelimeler: Mutlak deniz seviyesi, Sabit GPS, Deneysel Ortogonal Fonksiyon analizi, Spektral analiz. Long term absolute sea level changes at ANDENES and TREGDE tide gauges at Norwegian coasts are investigated by the analysis of the tide gauge and Continuous GPS time series. The spatial and temporal character of interannual to interdecadal sea level varitaions in tide gauge monthly mean sea level data and periodic signals in Continuous GPS height time series are determined by using Emprical Ortogonal Function and spectral analysis methods. The linear trends of both tide gauge and Continuous GPS height time series are calculated by harmonic analysis method with Least Squares Estimation. While no significant relative sea level trend is found at TREGDE, 2.04 ± 0.19 mm/year is found at ANDENES. While no significant absolute vertical movement is determined at TGDE and ANDE, the absolute vertical velocity of ANDO Continuous GPS station is 0.40 ± 0.10 mm/year and generally agrees with 0.89 mm/year land uplift determined by a Post Glacial Rebound model. The absolute sea level at ANDENES tide gauge is determined to be rising with a rate of 2.44 ± 0.21 mm/year by combining the vertical velocity of ANDE Continuous GPS station with the relative sea level trend. This value is consistent with the global sea level rise estimates which is in the order of 1-3 mm/year.Keywords: Absolute sea level, Continuous GPS, Emprical Orthogonal Function analysis, Spectral analysis.    

Some Dilemmas Regarding Teacher Training: On the Teacher’s (Not) Being a Role Model

In the research, the primary and secondary school teachers’ styles of teaching, beliefs and applications related to the teaching approach have been analyzed in terms of teaching applications. In the research, in which descriptive and qualitative analyses have been carried out, mixed method has been used. The research has been performed with totally 200 teachers consisting of 106 women, 94 men who are in charge in primary and secondary schools. In the research Anthony F. Grasha - Sherly Wetter Reichmann Learning Style scale and the constructivist learning environment scale developed by Tenenbaum, Naidu, Jegede and Austin have been used. Besides the diaries (80 diaries) written within the context of teaching applications by the 24 senior students in Faculty of Education have been analysed. Along with that the teachers have high levels of modelling, encouraging individualism, personal, advisor and counsellor teaching styles, it is seen that they have the teaching styles of information conveyor on a level higher than intermediate, and authoritative teaching style to a great extent. In the teacher candidates’ pre-service education, the differences between the existence of the role models “inappropriate” for the system or the approach and the beliefs and applications may cause the teacher candidates to suffer from some errors with regard to the role models in the education process

In vitro Antiprotozoal Activity of Extracts of five Turkish Lamiaceae Species

The in vitro antiprotozoal activities of crude methanolic extracts from the aerial parts of five Lamiaceae plants (Salvia tomentosa, S. sclarea, S. dichroantha, Nepeta nuda subsp. nuda and Marrubium astracanicum subsp. macrodon) were evaluated against four parasitic protozoa, i.e. Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and Plasmodium falciparum. The cytotoxic potentials of the extracts on L6 cells were also evaluated. Melarsoprol, benznidazole, miltefosine, chloroquine and podophyllotoxin were used as reference drugs. All crude MeOH extracts showed antiprotozoal potential against at least three parasites, so they were dispersed in water and partitioned against n-hexane and chloroform to yield three subextracts that were screened in the same test systems. The n-hexane extract of N. nuda was the most active against T. brucei rhodesiense while the CHCl3 extracts of S. tomentosa and S. dichroantha showed significant activity against L. donovani. All organic extracts displayed in vitro antimalarial and moderate trypanocidal activities against T. cruzi with the n-hexane extract of S. sclarea being the most active against the latter. The extracts displayed low or no cytotoxicity towards mammalian L6 cells

Ultrasound versus computed tomography scan findings in pediatric blunt abdominal traumas

Objective: We aimed to evaluate the performance of ultrasonography (US) versus computed tomography (CT) scan in detecting intra-abdominal injury among pediatric patients with blunt abdominal trauma. Methods: Pediatric patients aged<18, who were admitted to the emergency department (ED) due to abdominal trauma and underwent both US and CT scan were evaluated retrospectively. Results: A total of 732 pediatric patients were included in this study. Pathology was detected on US of 418 (57.1%) cases, whereas, intra-abdominal pathology was detected in CT scan of 359 (48.7%) cases. The sensitivity of US in detecting pathology (fluid and/or organ injury) was 95.3%, and its specificity was 79.6%. The sensitivity of US in detecting free fluid was 94.9%, and its specificity was 80.5%. In patients with unstable and stable hemodynamic, the sensitivities of US in detection of pathology (fluid and/or organ injury) were 97.6% and 91.6%, and its specificities were 74.3% and 80.9%, respectively. Conclusions: In our study, the sensitivity of US in terms of detecting pathology in pediatrics with blunt abdominal trauma was high, whereas the specificity of US was low