On weak structures due to Császár

In [4], Császár has introduced the notions of weak structures and the structures α(w), π(w), σ(w), β(w). The main aim of this paper is to introduce and study properties of the structures r(w), α(w), π(w), σ(w) and β(w).     

The adjacency-Jacobsthal-Hurwitz sequences in groups

In [3 Deveci, O., Aküzüm, Y. (in press). The adjacency-Jacobsthal-Hurwitz type numbers. Filomat. [Google Scholar]], Deveci and Aküzüm defined the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind. In this work, firstly we produce the cyclic groups from the multiplicative orders of the generating matrices of the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind when read modulo λ and we study the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind modulo λ. Then, we give the relationship between the orders of the cyclic groups obtained and the periods of the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind modulo λ. Further, we extend the adjacency-Jacobsthal-Hurwitz sequences of the first and second kind to groups and then we examine these sequences in the quaternion group Q₈ in detail.     

Gas chromatographic-mass spectrometric analysis of essential oils from Pimpinella species gathered from Central and Northern Turkey

Essential oils from 15 Pimpinella species were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. One species, Pimpinella anisum, in which only fruits were evaluated, was also included in the study. A total of 140 different compounds were identified and significant qualitative and quantitative differences were observed among the samples. Pimpinella essential oils were characterized as having mono-, sesqui- and trinorsesquiterpenoids, propenylphenols, and pseudoisoeugenols. Trinorsesquiterpenoids and phenylpropanoids appear to be chemical markers of Pimpinella species analyzed thus far. Essential oils obtained from Pimpinella roots share the same principal compound, epoxypseudoisoeugenyl-2-methylbutyrate at concentrations from 20 to 82.6%.     

Comparative spectral analysis of veterinary powder product by continuous wavelet and derivative transforms

Comparative simultaneous determination of chlortetracycline and benzocaine in the commercial veterinary powder product was carried out by continuous wavelet transform (CWT) and classical derivative transform (or classical derivative spectrophotometry). In this quantitative spectral analysis, two proposed analytical methods do not require any chemical separation process. In the first step, several wavelet families were tested to find an optimal CWT for the overlapping signal processing of the analyzed compounds. Subsequently, we observed that the coiflets (COIF-CWT) method with dilation parameter, a=400, gives suitable results for this analytical application. For a comparison, the classical derivative spectrophotometry (CDS) approach was also applied to the simultaneous quantitative resolution of the same analytical problem. Calibration functions were obtained by measuring the transform amplitudes corresponding to zero-crossing points for both CWT and CDS methods. The utility of these two analytical approaches were verified by analyzing various synthetic mixtures consisting of chlortetracycline and benzocaine and they were applied to the real samples consisting of veterinary powder formulation. The experimental results obtained from the COIF-CWT approach were statistically compared with those obtained by classical derivative spectrophotometry and successful results were reported.     

A numerical solution of 3D inviscid rotational flow in turbines and ducts

The numerical solutions of inviscid rotational (Euler) flows were obtained using an explicit hexahedral unstructured cell vertex finite volume method. A second-order-accurate, one-step Lax–Wendroff scheme was used to solve the unsteady governing equations discretized in conservative form. The transonic circular bump, in which the location and the strength of the captured shock are well predicted, was used as the first test case. The nozzle guide vanes of the VKI low-speed turbine facility were used to validate the Euler code in highly 3D environment. Despite the high turning and the secondary flows which develop, close agreements have been obtained with experimental and numerical results associated with these test cases. © 1998 John Wiley & Sons, Ltd.     

Generalized submaximal spaces

The notion of generalized submaximal spaces is introduced and studied. Properties and characterizations of generalized submaximal spaces are discussed.     

MEIR-KEELER TYPE CONTRACTIONS FOR TRIPLED FIXED POINTS

In 2011,Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces.In our paper,we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction.     

A new fractional wavelet approach for the simultaneous determination of ampicillin sodium and sulbactam sodium in a binary mixture

A new application of the fractional wavelet transform (FWT) was proposed for the simultaneous determination of ampicillin (AP) and sulbactam (SB) in a pharmaceutical combination for injection. FWT approach is a new powerful tool for removing noise and irrelevant information from the absorption spectra. Cardinal information having higher peak amplitude, eliminated noise, sharp peaks with shrinking width of spectral range was obtained by the application of FWT procedure to the original absorption spectra. In this paper, FWT approach was subjected to the data vector of the UV-signals obtained from AP and SB in the wavelength range of 211.5-313.8 nm. Derivative transform was applied to the original absorption signal together with its FWT generalization. The calibration graphs for AP and SB were obtained by measuring the FWT and usual derivative amplitudes at zero-crossing points. The method validation was carried out by using the synthetic mixture analysis. Our proposed FWT approach was compared with the usual derivative spectrophotometry and chemometric methods (CLS, PCR and PLS) and a good agreement was reported.     

3,4‐Bis[(4‐methoxy­benzo­yl)methyl­sulfanyl]thio­phene

A new type of thio­phene derivative having α‐thio­ketone groups at the 3‐ and 4‐positions, viz. the title compound, C₂₂H₂₀O₄S₃, has been prepared and studied by NMR spectroscopy and single‐crystal X‐ray diffraction techniques. The mol­ecule is nearly planar, the dihedral angles between the essentially planar thio­phene and benzene rings being 9.4 (1) and 10.6 (1)°. One of the thio­ketone O atoms is involved in an inter­molecular C—H⋯O hydrogen‐bonding inter­action.