The Essential Oil of a New Sideritis Species: Sideritis ozturkii Aytac and Aksoy

Water-distilled essential oils from flowering spikes ofSideritis ozturkii (Lamiaceae), a new species, were analyzed by GC/MS. The main components were found to be-pinene (31.1%, 16.0%, and 6.2%), and-pinene (20.2%, 14.2%, and 7.3%) in three samples collected from the same locality at different times     

Evaluation of in vivo analgesic activity of Scrophularia kotscyhana and isolation of bioactive compounds through activity-guided fractionation

The present study was undertaken to evaluate the in vivo analgesic activities of the extracts prepared from the aerial parts and roots of Scrophularia kotscyhana and to isolate the bioactive metabolites from the most active extract. Analgesic activities of all extracts and subextracts at the doses of 5, 10 and 30 mg/kg (i.p.) were examined using hot plate test in mice. Among the tested extracts, MeOH extract prepared from the aerial parts and the n-butanol subextract prepared thereof displayed the best analgesic activity at all doses. Phytochemical studies on n-butanol subextract led to the isolation of two new iridoid glycosides as an inseparable mixture, 8-O-acetyl-4′-O-(E)-(p-coumaroyl)-harpagide (1) and 8-O-acetyl-4′-O-(Z)-(p-coumaroyl)-harpagide (2) along with five known secondary metabolites, β-sitosterol 3-O-β-glucopyranoside (3), apigenin 7-O-β-glucopyranoside (4), apigenin 7-O-rutinoside (5), luteolin 7-O-β-glucopyranoside (6) and luteolin 7-O-rutinoside (7). The iridoid mixture (1 and 2), 3 and 4 elicited significant inhibition of pain at 5 mg/kg dose.     

A Korovkin type approximation theorems via $$\mathcal{I}$$ -convergence

Using the concept of -convergence we provide a Korovkin type approximation theorem by means of positive linear operators defined on an appropriate weighted space given with any interval of the real line. We also study rates of convergence by means of the modulus of continuity and the elements of the Lipschitz class.     

Statistical approximation to Bögel-type continuous and periodic functions

In this paper, considering A-statistical convergence instead of Pringsheim’s sense for double sequences, we prove a Korovkin-type approximation theorem for sequences of positive linear operators defined on the space of all real valued Bögel-type continuous and periodic functions on the whole real two-dimensional space. A strong application is also presented. Furthermore, we obtain some rates of A-statistical convergence in our approximation.     

Asymptotic expansions for the Sturm-Liouville problem by homotopy perturbation method

The asymptotic formulae for the eigenvalues and eigenfunctions of Sturm-Liouville problem with the Dirichlet boundary conditions when the potential is square integrable on [0, 1] are obtained by using homotopy perturbation method.     

Production of fungicidal oil and activated carbon from pistachio shell

The main objective of this study was to evaluate the feasibility of pistachio shell as a biomass feedstock for the production of fungicidal oil and a precursor for the production of activated carbon by physical activation. For this purpose, pistachio shell was pyrolyzed in a fixed bed reactor at the different temperatures (300-600 °C). The pyrolysis products were identified as gas, bio-oil, aqueous solution and char. The product distribution from pyrolysis process did not significantly change when the pyrolysis temperature was above 300 °C. The pyrolysis gas product had low calorific value since it contained the high proportion of carbon oxides. Because of their high oxygen content, the bio-oils were found not to be used as a fuel. Thus, the bio-oil was tested again four different types of fungi (pathogenetic, wood decaying and saprophyting). It was shown fungicidal activity again all tested fungi at the concentration of 10-50 mg ml⁻¹. The pyrolysis char was evaluated as a precursor for the production of activated carbon. The surface area and micropore volume of the activated carbon produced from the char by CO₂ activation at 900 °C were found to be 708 m² g⁻¹ and 0.280 cm³ g⁻¹, respectively.     

FePt nanocrystals embedded in methylmethacrylate polymers

A simple, controlled and reproducible procedure is reported to obtain polymerized methylmethacrylate by embedding monodisperse Fe₆₀Pt₄₀ nanoparticles. The magnetic properties of the composite material can be controlled by the magnetic properties and the concentration (up to 0.3 wt%) of the starting nanoparticle dispersions. SQUID magnetometry measurements of FePt-doped methylmethacrylate polymers show superparamagnetic behavior at room temperature confirming the homogeneous particle distribution and the non-occurrence of agglomerates inside the polymeric matrix also observed by transmission electron microscopy. Even at the highest concentration the average particle distances are so large that no particle interactions play a role.     

The Growth of P-type TlGaSe2(1−x) S2x Single Crystals

TlGaSe_2(1–x) S_2x single crystals were grown by the modified Bridgman-Stockbarger method in our crystal growth laboratory. A^IIIB^III C₂ ^VI compounds are formed of elements from vertical groups of the periodic table (group III: Tl, Ga, In; group VI: Se, S, Te) and are classified into two types. The first type has a layer structure: TlGaSe₂, TlGaS₂ and TlInS₂. The second type has a chained structure: TlInSe₂, TlInTe₂ and TlGaTe₂. None of the grown crystals had cracks and voids on the surface. The freshly cleaved crystals had a mirror-like surface and there was no need for mechanical or chemical polishing treatments. By the hot probe technique, we have found that the crystals were of p-type. The ingots produced were single crystalline and the useful region of single crystal was 90% with steps of 10 K if changes were small, and with steps of 3 and 5 K if changes were large in the direct and indirect band gaps energies. The direct and indirect band gaps for TlGaSe_2(1–x)S_2x samples were calculated as a function of temperature.     

Composition of the Essential Oils of Two Endemic Species from Turkey: Achillea lycaonica and A. ketenoglui

The hydrodistilled essential oils ofAchillea lycaonicaBoiss. & Heldr. andA. ketenogluiH. Duman were analyzed by GC/MS. The main components in the oils were trans-sabinene hydrate (9.3%) inA. lycaonicaand borneol (14.1%) and terpinen-4-ol (14.5%) inA. ketenoglui