Morkoc Karadeniz, S.; Ekinci, A.E.; Tuzluca, F.N.; Ertugrul, M.

Zinc sulfide thin films were deposited on bare glass by the chemical spray pyrolysis technique. 10-2 M Zinc acetate and 4 × 10 -2 M thiourea ((NH2)CS) were used as a precursor solution in this work. The temperature of the substrate was set at 350 °C. Deposited ZnS thin films show a hexagonal (wurtzite) phase structure. The crystalline quality and surface morphology of the deposited ZnS thin films were characterized using X-ray diffraction, atomic force microscopy and photoluminescence intensity. According to the XRD result, the (002) reflection is the most intense for films deposited at 350 °C.

Coldur, Fatih; Andac, Muberra

A potentiometric multi-sensor array, comprising of all-solid-state selective and non-selective electrodes, was constituted and calibrated via artificial neural networks (ANNs) for the determinations of NH4 +, Na+ and K+ ions in aqueous model solutions. Various artificial neural network configurations were constituted and their root mean square errors of calibration (RMSEC) and root mean square errors of prediction (RMSEP) values were calculated. The model which has the lowest RMSECxRMSEP value was preferred as the best model. Artificial neural network models calculated for Na+ and K+ have nearly similar prediction ability to univariate calibrations which were performed using the main ion concentrations of the calibration solutions and respective ion-selective electrode responses. Artificial neural network model calculated for NH4+ had the superior prediction ability when compared with its univariate calibration model.

Karadeniz, S. Morkoç; Ekinci, A.E.; Tuzluca, F.N.; Ertuorul, M.

Nickel oxide thin films were deposited by chemical spray pyrolysis. The influence of the nickel sulfate hexahydrate (NiSO4·6H 2O) precursor on the thin film properties was studied. Present experimental conditions such as the substrate temperature and precursor concentration which are 350 °C and 0.3 M, respectively, were investigated. It is found that pure NiO thin films crystallized in the cubic phase. Nickel oxide thin films have been annealed at 425 °C for 3 h under vacuum. It is found that annealing under vacuum is more efficient for the NiO films under the present experimental conditions. After the annealing process NiO thin film was evaluated by XRD, SEM and optical microscopy.

Sengül, Memnune; Yildiz, Hilal; Güngör, Neva; Okçu, Zühal

The objective of the present investigation is to determine total phenolic content, antioxidant activity, some physical and chemical properties of mulberry pestil (without additive, with glucose, with peanut, with walnut), plum pestil and cornelian cherry pestil. Total phenolic content of the water extracts of pestil samples was estimated as gallic acid equivalents (GAE) by Folin-Ciocalteu method spectrophotometrically. The antioxidant activity of water extracts prepared from pestil samples was measured by β-carotene bleaching method. Total phenolic content was found from 4.79 (mulberry pestil without additive) to 28.36 μg E/mg (plum pestil). The antioxidant activity of pestil samples varied from 40.05 % (mulberry pestil without additive) to 90.92 % (plum pestil). Dry matter, ash, protein, total sugar, reducing sugar, sucrose, pH, titratable acidity, colour (L, a, b), thickness of pestil samples were determined between 75.30-87.53 %, 0.18-3.42 %, 2.44-7.35 %, 30.91-54.60 %, 21.38-41.05 %, 0.83-27.54 %, 3.39-5.72 %, 0.06-6.25 % (malic acid); 27.35-41.35, (+1.25)-(+l 1.50), (+0.99)-(+l 8.22), 0.57-6.40 mm, respectively. The present study shows that pestil samples had high amount of phenolics content, antioxidant activity, carbohydrates and protein content.

Yigit, D.; Akar, F.; Baydas, E.; Buyukyildiz, M.

A comparative study on the elemental composition of various mulberry fruits and leaves was conducted with wavelength dispersive X-ray fluorescence (WDXRF). The element compositions of P, K, Ca, Mg, Na, Al, Si, S, Cl, Cr, Fe, Mn, Sr and Zn were determined in white (Morus alba), red (Morus rubra) and black (Morus nigra) mulberry leaves and fruits. Significant differences (p < 0.05 or p < 0.01) were observed in the mineral contents of mulberry leaves and fruits, depending on the species. The concentrations of elements in white, red and black mulberry leaves were 4.60, 4.53 and 4.61%, respectively of the total mass and the quantities of the elements were 2.13, 2.0 and 2.23% of the total mass. Among the various macronutrients in the mulberry species, K was present in the highest quantity for fruits samples, whereas Ca was predominant in the leaves. However, another result found with this study shows that the main advantage of this method is the non-modification of original sample, both during sample preparation and in the exciting X-ray beam. Therefore, this method might easily be used in the diagnosis of the nutrient status of fruit trees.

Yolcu, Halil; Serin, Yunus

Intercropping has been used widely in forage plant production all around the world. In intercropping systems, forage plants need different requirements are grown together. Requirement of fertilization and seeding pattern of intercropping differ from mono cropping. The research goals were to evaluate the effects of various seeding patterns and fertilization on the crude protein and chemical content of lucerne-smooth brome grass mixture under field conditions in 2002-2003. Lucerne and smooth bromegrass mixtures were established with different seeding patterns (mixed, alternative and cross-seeding), N fertilizer rates (0, 60 and 120 kg N ha-1) and P fertilizer rates (0, 40, 80 and 120 P2O5 ha-1). The results of this study indicated that different seeding patterns, N and P fertilization affected chemical contents of alfalfa and smooth brome grass mixture in the intercropping system. Depending on different seeding patterns, N, Ca, K and Mg content varied significantly, but no P content in the intercropping system. Nitrogen application increased N content and P application likewise increased P content. While P application increased N content, N application had no effect on the P content of the intercropping. Calcium and K did not vary significantly depending on N and P fertilization; yet, a relationship between P application and Mg content was determined.

Yigit, D.; Baydas, E.; Güleryüz, M.

A comperative study on elemental composition of various cherry fruits was conducted by using a sensitive method, wavelength dispersive X-ray fluorescence (WDXRF). Elements such as Na, Mg, Al, Si, Cl, K, Ca, Cr, Fe and Zn were determined in sweet (Prunus avium cv. Napolyon), sour (Prunus cerasus cv. Kütahya) and native cornelian (Cornus mas L.) cherries. Significant differences (p < 0.05 - p < 0.01) were observed in the mineral contents of cherry fruits. The concentration of elements in sour, sweet and cornelian cherry fruits was 1.21, 1.98 and 2.31 % of the total mass, respectively. Na was detected only in cornelian cherry fruits and its level was 150 ppm. The amounts of major elements potassium, magnesium, calcium and phosphor in cherry fruits were ranged to 9267-16778,1012-2113,510-2438 and 585-1546 ppm, respectively. The results show that the cherries are rich in the mineral elements that are of importance in man's well being. However, another result with this study shows that the main advantage of this method is the non-modification of the original sample, both during sample preparation and in the exciting X-ray beam.

Yigit, D.; Yigit, N.; Mavi, A.; Yildirim, A.; Güleryüz, M.

Antioxidant and antimicrobial studies were performed on methanol and water extracts of leaf, fruit and seed of Vitis vinifera L. cv. Karaerik. Lipid peroxidation inhibition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the amount of total phenolic compounds present in the extracts were determined. All parts of the plant have antioxidant potential. While seeds have the highest antioxidant potential, fruits have the lowest one. Antimicrobial activities of the above extracts were also tested against 96 clinical isolates of bacteria strains (Enterobacter aerogenes, Escherichia coli, Proteus miribalis, Pseudomonas aeroginosa, Staphylococcus aureus) and 90 Candida strains (Candida albicans, Candida glabrata, Candida guillermondii, Candida kefyr, Candida krusei, Candida parapisilosis, Candida pseudotropicalis, Candida tropicalis, Geotricum candidum) by disc-diffusion method and minimal inhibitory concentration (MIC) values of each active extract were determined. Water extracts of the grape leaves had shown the anticandidal activity against 3 Candida spp. (C. albicans, C. glabrata, C. tropicalis) and 1 bacteria species (S. aureus), and methanol and water extract of it have shown antibacterial activity against only Staphylococcus aureus with 13 mm inhibition zone and 0.625 mg/mL MIC value amoung the tested microorganisms. The highest anticandidal activity of leaves extract was found to be in their water extract against Candida albicans with 20 mm inhibition zone and 1.25 mg/mL MIC. Each one of the water and methanol extracts of seeds had shown antibacterial activity against three bacteria with inhibition zone range of 10-30 mm and 0.312-2.5 mg/mL MIC values. The highest activities were shown by water and methanol extracts of the seed against Staphylococcus aureus with 30 mm inhibition zone and 0.312 to 0.156 mg/mL MIC values, respectively. Unlike leaves and seeds extracts, none of the fruits extracts had shown antimicrobial activity.

Demir, Hulya; Coban, Abdulkadir; Ciftci, Mehmet

Catalaze (H2O2:H2O2 oxidoreductase; E.C 1.11.1.6) was purified from Coriander (Coriandrum sativum) leaves. The kinetic behaviour and some properties of the enzyme were also investigated. The purification was done at 4°C in two steps: (a) ammonium sulfate fractionation and (b) DEAE-Sephadex A50 ion exchange chomatography. The enzyme was obtained with a yield of 10.67 % and had a specific activity of 89.68 EU/mg protein. Optimum pH, stable pH, optimum temperature, molecular weight, KM and Vmax values for H2O2 was also determined. The overall purification was about 64.06-fold. SDS-PAGE of the purified enzyme showed a single band. Enzymatic activity was spectrophotometrically measured at 240 nm. The molecular mass was estimated to be 60.95 kDa by SDS-PAGE and 58.12 kDa by Sephadex G-150 gel filtration column chromatography. The enzyme had optimum pH at 7.3 and was stable at pH 7.3 in 0.1 M tris-HCl buffer. The optimum temperature was at 30°C. The KM value for H2O2 was 7.87 mM. The Vmax value for this substrate was 42.19 EU/mL.

Yolcu, Halil; Dasci, Mahmut; Turan, Metin

The purpose of this study was to assess the mineral contents of twelve lucerne cultivars on the highlands for livestock. Lucerne cultivars (Bilensoy, alfa-484, Resis, alfa-1312, Savas, Kayseri, alfa-1313, Planet, Seker, Daisy, Bilensoy-80, CW-3567) were collected from cultivated fields. In general, Ca, Fe and Mn contents of the lucerne cultivars were the highest in Bilensoy cultivar, N in Planet cultivar, K in Savas cultivar, P in Daisy cultivar, Mg in alfa-1313 cultivar and Zn and Cu in Bilensoy-80 cultivar. Bilensoy, Daisy and Seker cultivars especially had very high mineral contents. The determination of mineral contents of Lucerne cultivars has been a phase in the evaluation of impacts to animal feeding. Lucerne cultivars had a very high nutritional potential and their N, P, K, Ca, Mg, Na, Fe and Zn values were higher than those required for animal nutrition. Because of high digestion, taste, cheapness of Lucerne plant and provision of macro and micro mineral, it has very important raw material nutrition for animal nourishment.