Showing papers by "Ahi Evran University published in 2011"

Boundedness of Sublinear Operators and Commutators on Generalized Morrey Spaces

Abstract: In this paper the authors study the boundedness for a large class of sublinear operators \({T_{\alpha}, \alpha \in [0,n)}\) generated by Calderon–Zygmund operators (α = 0) and generated by Riesz potential operator (α > 0) on generalized Morrey spaces \({M_{p,\varphi}}\) . As an application of the above result, the boundeness of the commutator of sublinear operators \({T_{b,\alpha}, \alpha \in [0,n)}\) on generalized Morrey spaces is also obtained. In the case \({b \in BMO}\) and Tb,α is a sublinear operator, we find the sufficient conditions on the pair \({(\varphi_1,\varphi_2)}\) which ensures the boundedness of the operators \({T_{b,\alpha}, \alpha \in [0,n)}\) from one generalized Morrey space \({M_{p,\varphi_1}}\) to another \({M_{q,\varphi_2}}\) with 1/p − 1/q = α/n. In all the cases the conditions for the boundedness are given in terms of Zygmund-type integral inequalities on \({(\varphi_1,\varphi_2)}\) , which do not assume any assumption on monotonicity of \({\varphi_1, \, \varphi_2}\) in r. Conditions of these theorems are satisfied by many important operators in analysis, in particular, Littlewood–Paley operator, Marcinkiewicz operator and Bochner–Riesz operator.

Comparative phylogeography of two African carnivorans presumably introduced into Europe: disentangling natural versus human-mediated dispersal across the Strait of Gibraltar

Abstract: Aim Natural processes of colonization and human-mediated introductions have shaped current patterns of biodiversity in the Mediterranean Basin. We use a comparative phylogeographic approach to investigate the genetic structure of Herpestes ichneumon and Genetta genetta (Carnivora) across the Strait of Gibraltar, and test for their supposedly contemporaneous introduction into Iberia. Location Mediterranean Basin and Africa. Methods We sequenced two mitochondrial fragments (cytochrome b and control region) of 91 (H. ichneumon) and 185 (G. genetta) individuals, including the sole archaeological record of G. genetta in Iberia, dating from the Muslim occupation. We used phylogenetic and tokogenetic methods, summary statistics, neutrality tests, geographic–genetic pairwise comparisons and coalescent estimates to explore the history of the two species in the Mediterranean Basin. Results In North Africa, an autochthonous (Clade I) and a western African mtDNA clade, coalescing in the Middle to Late Pleistocene, co-occurred in both species. Only Clade I was present in Europe. In H. ichneumon, the European pool showed deep coalescence (median = 335 kyr) and high genetic differentiation and diversity compared with its North African counterpart, suggesting long-term stability of female effective population size. In sharp contrast, G. genetta in Europe exhibited lower genetic diversity, weak differentiation with North Africa and recent demographic expansion; however, Andalusia and Catalonia (Spain) showed distinctly higher genetic diversity, and the archaeological specimen had the predominant European haplotype. Main conclusions The co-occurrence of autochthonous and sub-Saharan lineages in North Africa (1) supports a new, emerging biogeographic scenario in North Africa, and (2) suggests a connection through the Sahara, possibly from the Middle Pleistocene onwards. Our results refute the idea that H. ichneumon was introduced into Europe contemporaneously with G. genetta. Instead, they support a scenario of sweepstake dispersal during Late Pleistocene sea-level fluctuations, followed by long-term in situ evolution throughout the last glaciation cycles. Genetta genetta appears to have undergone a recent spread from at least two independent introduction ‘hotspots’ in Catalonia and Andalusia, possibly following antique trade routes and/or Muslim invasions. Despite their contrasting histories, the European gene pools of both species represent unusual cases leading to the preservation of autochthonous, North African lineages.

Boundedness of the Riesz Potential in Local Morrey-Type Spaces

Abstract: The problem of boundedness of the Riesz potential in local Morrey-type spaces is reduced to the problem of boundedness of the Hardy operator in weighted L p -spaces on the cone of non-negative non-increasing functions. This allows obtaining sharp sufficient conditions for boundedness for all admissible values of the parameters, which, for a certain range of the parameters wider than known before, coincide with the necessary ones.

Synthesis, molecular conformation, vibrational, electronic transition, and chemical shift assignments of 4-(thiophene-3-ylmethoxy)phthalonitrile: a combined experimental and theoretical analysis

Abstract: This work presents the synthesis and characterization of a novel compound, 4-(thiophene-3-ylmethoxy)phthalonitrile (TMP). The spectroscopic properties of the compound were examined by FT-IR, FT-Raman, NMR, and UV techniques. FT-IR and FT-Raman spectra in solid state were observed in the region 4000–400 cm−1 and 3500–50 cm−1, respectively. The 1H and 13C NMR spectra were recorded in CDCl3 solution. The UV absorption spectrum of the compound that dissolved in THF was recorded in the range of 200–800 nm. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR and FT-Raman spectra. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts (13C NMR and 1H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The HOMO and LUMO analyses have been used to elucidate information regarding charge transfer within the molecule. Comparison of the calculated frequencies, NMR chemical shifts, absorption wavelengths with the experimental values revealed that DFT method produces good results.

Turkish school students and global warming beliefs and willingness to act

Abstract: One aim of environmental education is to persuade people to act in more proenvironmental ways. However, there is not a linear relationship between environmental knowledge in general and a willingness to act pro-environmentally. This research explores, using a specially-devised questionnaire, Turkish school students’ beliefs about the benefits of specific actions for reducing global warming (their Believed Usefulness of Action), their readiness to adopt them (their Degree of Willingness to Act), and the relationships between these. Students appear willing to take certain actions such as switching off un-used electrical items, but unwilling to undertake other actions such as increasing their use of public transport. Planting more trees was thought to be the most useful action, whereas few students appreciated the role that buying fewer new consumables might play. A novel index, the Potential Effectiveness of Education, was constructed to quantify the relationships between these two parameters for specific actions. For some actions, such as purchasing fewer new goods, there were stronger relationships between a belief in the effectiveness of an action in reducing global warming and the willingness to undertake it. Teaching about the benefits of such actions might be effective in terms of encouraging individuals to adopt them.

Parametric cost estimation system for light rail transit and metro trackworks

Abstract: The main objective of this work is to develop early cost estimation models for light rail transit and metro trackworks using the multivariable regression and artificial neural network approaches. These two approaches were applied to a data set of 16 projects by using 17 parameters available at the early design phase. The regression analysis estimated the cost of testing samples with an error of 2.32%. On the other hand, artificial neural network estimated the cost with 5.76% error, which was slightly higher than the regression error. As a result, two successful cost estimation models have been developed depending on the findings of this paper. These models can effectively be utilized in the tender decision-making phase of projects with trackworks.

Synthesis of cationic N‐[3‐(dimethylamino)propyl]methacrylamide brushes on silicon wafer via surface‐initiated RAFT polymerization

Abstract: Surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization of N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA) on the silicon wafer was conducted in attempt to create controllable cationic polymer films. The RAFT agent-immobilized substrate was prepared by the silanization of hydroxyl groups on silicon wafer with 3-aminopropylthriethoxysilane (APTS) and by the amide reaction of amine groups of APTS with ester groups of 4-cyano-4-((thiobenzoyl) sulfanyl) pentanoic succinimide ester (CPSE); followed by the RAFT polymerization of DMAPMA using a “free” RAFT agent, that is, 4-cyanopentanoic acid dithiobenzoate (CPAD) and an initiator, that is, 4,4′-azobis-4-cyanopentanoic acid (CPA). The formation of homogeneous tethered poly(N-[3-(dimethylamino)propyl]methacrylamide) [poly(DMAPMA)] brushes, whose thickness can be tuned by reaction time varying, is evidenced by using the combination of grazing angle attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and water contact-angle measurements. The calculation of grafting parameters from the number-average molecular weight, Mn (g/mol) and ellipsometric thickness, h (nm) values indicated the synthesis of densely grafted poly(DMAPMA) films and allowed us to predict a polymerization time for forming a “brush-like” conformation for the chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Electrical conduction properties of In-doped ZnO thin films

Abstract: The electrical conduction mechanism of undoped and In-doped ZnO thin films is investigated. The behavior of conductivity is consistent with the variable-range hopping conduction mechanism. From the experimental data, the values of the density of states at the Fermi level, the hopping distance and the average hopping energy are obtained. The effect of these parameters on In doping level is discussed. It was found that the value of the density of states at the Fermi level increases with increasing In doping level, which is the reason for the rise in conductivity of the films.

Ni doping effect on electrical conductivity of ZnO nanocrystalline thin films

Abstract: The electrical conductivity behavior of undoped and Ni-doped ZnO nanocrystalline thin films prepared by spin-coating method was investigated as a function of temperature. The films were found to have polycrystalline structure. Grain size and the conductivity of the films were found to decrease significantly with increase in Ni concentration. This behavior was well explained by the grain boundary conduction model that takes into account electron trapping in surface states. It was observed that by increasing the Ni-doping level the surface trap density increases and implicitly the conductivity decreases.

Multiphonon hopping of carriers in CuO thin films

Abstract: We have performed a detailed study of the electrical conduction process in CuO thin films deposited by the sol–gel dip coating technique in a temperature range 280–420 K. The electrical conduction is analyzed within the framework of various hopping conduction models. Multiphonon hopping conduction mechanism is found to dominate the electrical transport in the entire temperature region. Our results are consistent with this model of hopping conduction mechanisms with weak carrier–lattice coupling.

Extraction of important electrical parameters of CuO

Abstract: Conductivity, X-ray diffraction (XRD), optical absorption and atomic force microscopy (AFM) measurements of CuO thin film were presented. Three distinct electrical conduction contributions with discrete characteristic activation energies were observed. The applicability of various theoretical models was considered to explain results on electrical transport. We extracted important electrical parameters of CuO, which might be useful for its gas sensor applications.

Effect of plant extracts on lipid oxidation during frozen storage of minced fish muscle

Abstract: Summary The aim of the study is to determine the effect of pomegranate seed extract (PSE) and grape seed extract (GSE) addition to chub mackerel minced muscle on lipid oxidation during frozen storage. Each extract was added to minced fish muscle at 2% concentration and then stored at −18 °C for 3 months. The effect of plant dietary fibres to control lipid oxidation was compared with untreated samples (control). Formation of lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) was significantly inhibited by PSE and GSE addition when compared with control. Both extracts significantly retarded lipid oxidation according to the results of TBARS. A significant reduction of L* (lightness), a* (redness) and b* (yellowness) values was detected during frozen storage. GSE added samples had the highest redness and the lowest lightness and yellowness. However, samples with PSE showed the lowest redness and highest yellowness and h° (hue angle) values. The results from this study suggest GSE is a very effective inhibitor of primary and secondary oxidation products in minced fish muscle and have a potential as a natural antioxidant to control lipid oxidation during frozen storage of fatty fish.

An Analysis of Internet Addiction Levels of Individuals according to Various Variables.

Abstract: The concept of internet addiction refers to the excessive use of internet which in turn causes various problems in individual, social and professional aspects. The aim of this study was to determine internet addiction levels of internet users from all age groups. The study used survey model. Study group of the study consisted of a total of 596 people from all age groups. “Personal Information Form” and “Internet Addiction Scale” were used for data collection. Arithmetic mean, standard deviation, independent sampling and t test, ANOVA and LSD tests were performed on collected data. The findings of the study revealed that the individuals had low levels of internet addiction both in sub-scales and in the general of the scale according to age groups. It was found that there was a significant difference between internet addiction scores of the individuals who belonged to the age group of 19 and below and 30 and below. There was a significant difference between the internet addiction scores of students and other professional groups. It was found that internet addiction levels of males were higher than those of females. The results of the study were discussed together with the results of different studies and suggestions were made.

Electrical conduction mechanism and gas sensing properties of Pd-doped TiO2 films

Abstract: Undoped and Pd-doped titanium oxide thin films (0.5 wt.%) were prepared by the sol–gel technique (dip-coating) on glass and silicon substrates. The as-deposited thin films were compacted by subjecting them to different annealing temperatures (300 °C, 500 °C). The dependences of the electrical conductivity vs. inverse temperature were investigated in air and in vacuum. A study of the effects of Pd-doping, annealing temperature and ambient conditions on their electrical properties was performed. The sensing behavior of titanium oxide thin films exposed to some reducing gases (methane, acetone, ethanol, formaldehyde and liquefied petroleum gas) was carried out, by means of electrical conductivity measurements. All the studied films are most sensitive to formaldehyde, with a special remark for the Pd-doped ones deposited on silicon substrates.

Boundedness of a Class of Sublinear Operators and Their Commutators on Generalized Morrey Spaces

Abstract: The authors study the boundedness for a large class of sublinear operator generated by Calderon-Zygmund operator on generalized Morrey spaces . As an application of this result, the boundedness of the commutator of sublinear operators on generalized Morrey spaces is obtained. In the case , and is a sublinear operator, we find the sufficient conditions on the pair () which ensures the boundedness of the operator from one generalized Morrey space to another . In all cases, the conditions for the boundedness of are given in terms of Zygmund-type integral inequalities on (), which do not assume any assumption on monotonicity of in . Conditions of these theorems are satisfied by many important operators in analysis, in particular pseudodifferential operators, Littlewood-Paley operator, Marcinkiewicz operator, and Bochner-Riesz operator.

A Path Analysis Study of School Culture and Teachers' Organisational Commitment

Abstract: In this study, the direct and indirect relations between school culture and the organisational commitment of primary school teachers were analyzed. The subjects of the research consisted of primary school teachers who worked at a district in Istanbul in the academic year 2007-2008. The sampling group was defined by the cluster sampling method. In total 200 teachers participated. Two scales were used to collect data, the organisational commitment scale (OCS) and the school culture scale (SCS). Linear regression and path analysis were used to explain the influence of school culture on organisational commitment, and LISREL 7 was used as a structural equation model. The findings indicated that although there was a positive correlation between school culture and organisational commitment, the direct effect of school culture on organisational commitment was not meaningful.