Genotyping of the kappa‐casein and beta‐lactoglobulin genes in Anatolian water buffalo by PCR‐RFLP

The objective of this study was to identify allele and genotype frequencies of the κ‐CN and β‐LG genes in Anatolian water buffalo. A total of 126 water buffalos from Turkey were genotyped using the PCR‐RFLP method. For gene κ‐CN, only B allele and BB genotype were observed. And for gene β‐LG, two types of alleles (A and B) and three types of genotypes were observed. The genotype frequencies of AA, AB and BB of β‐LG in Anatolian water buffalo were 0.254, 0.698 and 0.048, respectively. Surprisingly, the frequency of allele A was higher than that of allele B in contrast to world buffalo breeds.     

Hydrogen production probability distributions for a PV-electrolyser system

In this study, we comprehensively analyze the probability distribution of the hydrogen production for PV assisted PEM electrolyser system. A case study is conducted using the experimental data taken from a recently installed system in Balikesir University, Turkey. A novel computational tool is developed in Matlab-Simulink for analyzing the data. The concept of probability density frequency is successfully applied in the analyses of the wind speed and the solar energy in literature. This study presents a method of applying this knowledge to solar energy assisted hydrogen production. The change in the probability distribution of the hydrogen production with the solar irradiation throughout a year is studied and illustrated. It is found that the maximum amount of hydrogen production occurs at between 600 and 650 W/m² of solar radiation. Annual hydrogen production is determined as 2.97 kg for per m² of PV system. Average hydrogen production efficiency of the studied PEM electrolyser is found to be 60.5% with 0.48 A/cm² of current density. The presented results of this study are expected to be valuable for the researchers working on renewable hydrogen production systems.     

Optical, structural and surface characterization of CdO:Mg films

In this work, we have tried to improve some physical properties of CdO films by Mg doping. Ultrasonic spray pyrolysis technique has been used to obtain the films. Thicknesses and refractive indices of the films have been determined by Spectroscopic ellipsometry technique using Cauchy-Urbach model for fitting. Transmission and reflectance spectra have been taken by UV Spectrophotometer, and band gap values have been determined by optical method. X-ray diffraction patterns have been used to study the structural properties. Texture coefficient, grain size and lattice constants have also been determined. AFM images have been taken to see the effect of Mg doping on surface topography and roughness of CdO films. Finally, it has been concluded that Mg doped CdO films (especially at 4%) have improved properties and are good candidates for photovoltaic applications.     

Mode I and mixed mode fracture studies in brittle materials using the Brazilian disc specimen

High Strength Cement Mortar (HSCM) with very fine sand exhibits a typical brittle behavior. In the present work, a linear elastic fracture mechanics based model is used for the fracture studies conducted on this material. The experimental testing program is based on the diametral compression test of disc specimens containing an internal slant crack. Under the Mode I loading condition, the test method which has been previously used is applied to determine the critical value of the stress intensity factor, K_IC, for HSCM. The same dise specimen is also tested under combined Mode I and Mode II loading conditions. By changing the notch orientation angle with respect to the loading direction, the mode of fracture is varied from pure Mode I to Mixed-Mode. Based on the Mixed-Mode fracture envelope, it is shown that the disc specimen which is currently used for several brittle materials provides a wide range of |K_II|/K₁ ratios. In pure Mode I loading case, after determining K_IC, it is possible to obtain the graph of normalized critical load versus normalized crack length. For the purpose of comparison, some available experimental data on Mode I and/or Mixed Mode fracture of some other brittle materials such as glass, sintered carbide, and polymethyl methacrylate (PMMA) were also evaluated. It can be concluded that there is a good fit between the experimental results and the theory.

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Résumé Les mortiers à très haute résistance (MTHR) préparés avec du sable très fin ont exhibité un comportement typiquement fragile. Dans cet article un modèle de rupture élastique linéaire est utilisé pour étudier la rupture de ces matériaux. L'étude expérimentale consistait des essait des consistait des essais de compression diamétrale sur des éprouvettes en forme de disques contenant une fissure inclinée. Les essais conformes au Mode I utilisés auparavant sont appliqués pour déterminer la valeur critique du facteur d'intensité de la contrainte K_IC du MTHR. Les mêmes éprouvettes ont été ensuite essayées sous charge combinée du Mode I et Mode II. En changeant l'angle d'orientation de l'entaille par rapport à la direction de la force appliquée, le mode de rupture a été modifié du Mode I au Mode-Mixte. En se servant de l'enveloppe du Mode-Mixte de rupture, utilisée actuellement on a montré que l'éprouvette disque pouvait fournir une large pour les rapports |K_II|/K₁. Au cas de chargement simple de Mode I, après avoir déterminé K_IC il était possible d'obtenir un graphique entre la charge critique et la longueur de la fissure normalisées. D'autres résultats expérimentaux obtenus sur d'autres matériaux fragiles comme verre, carbide synthérisé et méthacrylate de polymethyl (PMMA) sont aussi évalués afin de réaliser une comparaison. On peut conclure qu'il existe une bonne conformité entre les résultats expérimentaux et théoriques.

     

Comparison of different irrigation activation techniques on smear layer removal: An in vitro study

The purpose of this study was to evaluate the efficiency of different irrigation activation techniques on smear layer removal. About 80 single‐rooted human maxillary central teeth were decoronated to a standardized length.The samples were prepared by using ProTaper system to size F4 and divided into eight equal groups (n = 10) according to the final irrigation activation technique; distilled water was used as an irrigant in Group 1. The other groups were treated with 2.5% NaOCl and 17% EDTA, respectively. Conventional syringe irrigation (CSI) was used in Group 2. Irrigation solutions were activated using passive ultrasonic irrigation (PUI, Group 3), EndoVac apical negative pressure (ANP, Group 4), diode laser (Group 5), Nd:YAG laser (Group 6), Er:YAG laser (Group 7), and Er:YAG laser using with photon‐induced photoacoustic streaming (PIPS?, Group 8). Teeth were split longitudinally and subjected to scanning electron microscope (SEM). PIPS showed the best removal of smear layer when compared with PUI, ANP, Nd:YAG, and Er:YAG, but the difference was not statistically significant (P > 0.05). Smear layer scores obtained with PIPS technique were statistically significant different from those of obtained with control, CSI and diode laser groups (P < 0.05). All experimental irrigation techniques except ANP and diode laser removed smear layer more effectively at the coronal and middle levels compared to the apical level (P < 0.05). Irrigation activated/delivered techniques except diode laser have a positive effect on removing of smear layer. Microsc. Res. Tech. 78:230–239, 2015. © 2015 Wiley Periodicals, Inc.     

Spring Fatigue Fractures Due to Microstructural Changes in Service

Multiple in-service fractures of torsion springs were experienced in the same system, which was the support assembly to the electrical pickup for an electric-powered vehicle, similar to a subway rail car or electric trolley car. Scanning electron microscopy and metallographic examinations determined that the fractures initiated due to electric arc damage. Intergranular quench cracks at the spring surface through the transformed untempered martensite provided crack initiations for fatigue that propagated during operation.     

Grayanotoxin-III Detection and Antioxidant Activity of Mad Honey

“Mad honey” is a complex mixture of numerous chemicals produced by honeybees from Rhododendron flowers. Consumption of mad honey leads to diarrhea, perspiration, dizziness, changes in consciousness, syncope, diplopia, as well as blurred vision, hypotension, and bradycardia due to the presence of grayanotoxins (GTXs). Therefore, it is important to detect the level grayanotoxins in mad honey. Besides its toxicity, mad honey also has antioxidant activity. This study was designed to determine the level of grayanotoxin-III toxin and antioxidant activity of ten different mad honey samples collected from the Black Sea region of Turkey. Liquid chromatography-tandem mass spectrometry was used for the quantitation of grayanotoxin-III. Antioxidant activity was evaluated using total phenolic contents, total ferric reducing antioxidant power, scavenging of 2,2-diphenyl-1-picrylhydrazyl and 3-(2-pyridyl)-5, 6-diphenyl-1,2,4-triazine-4’,4’’-disulfonic acid radicals. Quantities of grayanotoxin-III levels ranged from 68.754 to 0.701 µg grayanotoxin-III/g honey. Mad honey MH7 from Artvin/Hopa had the highest grayanotoxin-III level. Although there were varying levels of grayanotoxin-III, mad honey samples were outstanding in terms of antioxidant activity. MH₃ had the highest antioxidant potential. Although toxicity effect comprises, a metered dose of mad honey might also be explored as a potential source in clinical trials due to high bioactivity levels.     

Preparation and characterization of aluminum-incorporated cadmium oxide films

Opto-electronic and photovoltaic solar cell technologies which are developing day by day need novel and alternative materials. Also, economic cost is the other important parameter when producing and using these materials. With this purpose, we have prepared aluminum-incorporated CdO films by ultrasonic spray pyrolysis (USP) technique. Firstly, elemental analyses were performed to observe the distribution rate of Al in the structure. We have attempted to explain the structural and electrical properties of these films in detail. The crystalline structure was studied by X-ray diffraction (XRD). Besides, some structural parameters such as texture coefficient, grain size and dislocation density were calculated. Van der Pauw and Hall measurements were used to investigate the electrical properties. Electrical conductivity, carrier concentration and mobility values were determined for all films. Finally, we conclude that Al-incorporated CdO films with low Al concentrations will be promising materials for future works because of their high conductivity and mobility values as compared to others.