5,716 research outputs found
Two-Dimensional Ferroelectric Photonic Crystals: Optics and Band Structure
In this report we present an investigation of the optical properties and band
structure calculations for the photonic structures based on the functional
materials- ferroelectrics. A theoretical approach to the optical properties of
the 2D and 3D photonic crystals which yields further insight in the phenomenon
of the reflection from different families of lattice planes in relation to the
presence of photonic gaps or photonic bands. We calculate the photonic bands
and optical properties of LiNbO3 based photonic crystals. Calculations of
reflection and transmission spectra show the features correspond to the onset
of diffraction, as well as to additional reflectance structures at large values
of the angle of incidence.Comment: 10 pages, 4 figures, 1 table, This paper were presented at 21 st
International Symposium on Applications of Ferroelectrics (ISAF ECAPD PFM
2012 Averio, Portugal) and accepted for publication in Ferroelectrics (2013
Evaluation of selected fig genotypes from South east Turkey
Turkey has great variations and distributions in wild fig forms as well as fig cultivars. This study was carried out in Mardin and anlýurfa provinces during 2004 - 2005. Nine fig genotypes were evaluated in this selection study for two years. In this study, some morphological characteristics investigated were tree growth habit, tree vigour, relative degree of branching, leaf shape and leaf margin dentation. Also, the characteristics of all the fig genotypes were identificated. 63-07-006 and 63-07-007 fig genotypes which had the highest scores in all the fig genotypes according to analysis in the weighted rankedmethod were evaluated to be best table fig genotypes. In pomological characteristics, fruit weight ranged between 71.77 g (47-02-003) and 43.29 g (63-07-005). Some other values were: 65.26 mm (47-02-003) and 46.99 mm (47-02-019) of width; 56.87 mm (47-02-003) and 38.23 mm (47-02-008) of length; 4.44 mm (63-07-007) and 3.58 mm (47-02-020) of ostiole width; 28.57% (47-02-012) and 16.87% (63-07-007) of total soluble solids (TSS) ratio were determined
Static and vibration analysis of functionally graded beams using refined shear deformation theory
Static and vibration analysis of functionally graded beams using refined shear deformation theory is presented. The developed theory, which does not require shear correction factor, accounts for shear deformation effect and coupling coming from the material anisotropy. Governing equations of motion are derived from the Hamilton's principle. The resulting coupling is referred to as triply coupled axial-flexural response. A two-noded Hermite-cubic element with five degree-of-freedom per node is developed to solve the problem. Numerical results are obtained for functionally graded beams with simply-supported, cantilever-free and clamped-clamped boundary conditions to investigate effects of the power-law exponent and modulus ratio on the displacements, natural frequencies and corresponding mode shapes
Effects of different irrigation regimes and nitrogen levels on yield and quality of melon (Cucumis melo L.)
In order to study the effects of different irrigation regimes and nitrogen (N) levels on yield and some yield components of melon, a research was conducted at the Agricultural Experimental Field of the Harran University (Sanliurfa, Turkey) during the growth periods of 2007 and 2008. The growing season of melon was divided into four phenological stages: (i) Stage I, from seed germination to beginning of flowering; (ii) stage II; from beginning of flowering to small fruit, (iii) stage III; from small fruit to fullexpanded fruit and (iv) stage IV; from full-expanded fruit to harvesting. Regulated deficit irrigation (RDI), deficit irrigation (DI), full (I-full) and excessive irrigation (I-excessive) strategies were examined. The irrigation treatments were 33% (I0.33), 67% (I0.67), 100% (I1.00), and 133% (I1.33) ratios of total irrigation water applied (IW)/cumulative pan evaporation (CPE) with four day irrigation interval. Totally, 28 treatments were designed and applied as combination of nitrogen and irrigation levels. Four nitrogen treatments were: Control (N1), basic fertilizer (100 kg ha-1 pure N); N2, basic fertilizer + 30; N3, basic fertilizer + 60 and N4, basic fertilizer + 90 kg ha-1 as urea. The field experiment was setup employing a randomized split-plot design with three replications. N levels were assigned to the main plot and irrigation to the sub plot. Irrigation water amount applied, fruit yield and some quality parameters, yield response factor, irrigation water use efficiency, water use efficiency, water saving at different N levels and irrigation regimes were determined. Results show that irrigation regimes and N levels had significant effects on fruit yield. The best combination of treatments was N3*DI-low (T19) with a yield of 59.77 t ha-1 which corresponds to 10% yield loss providing 55% water saving. It could be applied for sustainable production, saving a significant amount of water and increasing the nitrogen use efficiency, where water is scarce.Key words: Melon, regulated deficit irrigation (RDI), nitrogen, yield
Fruit characteristics of the selected fig genotypes
The aim of this research was determine of fruit characteristics and select of some significant fig genotypes grown in Kiziltepe district of Mardin province. No studies have been made on the fig genotypes in Kiziltepe district by researchers up to now. Therefore, this study was very important. In this research, six fig genotypes were evaluated for two years. A lot of pomological characteristics of the selected fig genotypes were determined during years 2007 and 2008. According to the averages in two years, fruit weight ranged between 68.04 and 43.96 g,ostiolum width ranged between 4.55 and 2.46 mm, total soluble solids (TSS) ranged between 21.10 and 16.78% and acidity ranged between 0.28 and 0.22%. In addition, KZTP-32 and KZTP-30 fig genotypes scored the highest in overall quality according to the results of the weighted ranked method.Key words: Ficus carica L., genotype, fruit characteristics, quality, selection
Effects of deficit irrigation on yield and yield components of vegetable soybean [Glycine max L. (Merr.)] in semi-arid conditions
Vegetable soybeans [Glycine max L (Merr.)] are very sensitive crops to environmental conditions during their growth stages, especially in term of water scarcity. Water scarcity is one of the major environmental factors influencing sustainable agricultural production in arid and semi-arid regions. Careful management irrigation strategies need to save irrigation water with marginal yield reduction. The objective of this research was to investigate the effects of the water deficit on yield and yield components of soybean in semi-arid conditions. This research was carried out at the Agricultural Experimental Field of the Harran University (Sanliurfa, Turkey) on clay soil during the growth periods of 2006 and 2007. The irrigation treatments were 33% (I33), 67% (I67), 100% (I100) and 133% (I133) ratios of total irrigation water applied (IW)/cumulative pan evaporation (CPE) with four day irrigation interval. The average amount of irrigation water applied to treatments (I133, I100, I67 and I33) was 1058, 795, 533 and 263 mm and 1094, 823, 551 and 272 mm for Toyokomachi and Toyohomare cultivars, respectively. The maximum green pod yields were 20.6 and 29.1 t ha-1 with 997 and 922 mm water consumption for Toyohomare and Toyokomachi, respectively in I133 treatments. Yield response factor (ky) values of I100, I67 and I33 treatments were determined as 2.17, 0.92 and 0.59 for Toyohomare and 3.50, 0.61 and 0.61 for Toyokomachi, respectively. The results of the study implied that at least equal (I100) or excess of the evaporated water amount is required to produce high yield in soybean. Differences of yield between cultivars in response to irrigation levels make it necessary to select less sensitive cultivars to water stress especially in semi-arid and arid areas. Varietal characteristics must be considered for successful growing of soybean.Key words: Soybean, Glycine max, deficit irrigation, water deficit
Effects of rootstocks and irrigation levels on grape quality of Vitis vinifera L. cv. Shiraz
The influence of two rootstocks (SO4 and 1103P) on grape quality and berry chemical composition was studied in a factorial experiment, in field grown grapevines of cv. Shiraz (Vitis vinifera L.), subjected to five irrigation levels [0% (T1), 25% (T2), 50% (T3), 75% (T4) and 100% (T5) of irrigation depth (IW, mm): Class A pan evaporimeter (CPE)]. Spectrophotometric analyses of total anthocyanins (TA), total phenolics (TP) and total antioxidant activity (AA) in grape extracts were performed. Also, total soluble solids (TSS), total acidity, pH, total sugar content, ash, juice yield and color index of red grapes (CIRG) of berry samples were determined. TA, TP, AA, TSS, total sugar content, ash, and CIRG valuesdecreased together with increasing irrigation levels. On the contrary, T4 and T5 irrigation treatments increased total acidity, pH and juice yield of samples compared to the effects of T1, T2 and T3 irrigation treatments for both rootstocks. Moreover, T1 or T2 treatments caused an increase in TA, TP, AA, TSS, total sugar content, ash, and CIRG index values of grape samples in comparison to that of vines irrigated with T3, T4 and T5 levels. Grape quality response to irrigation levels was altered by rootstocksand quality of grapes harvested from vines grafted on SO4 was higher compared to those from 1103P under all irrigation treatments. Based on the findings, it was suggested that T2 irrigation level might be sufficient to guarantee Shiraz yield potential without significant loss in grape quality under the study conditions. Also, the results make it possible to recommend use of SO4 rootstock under non-limiting water conditions because of its positive on grape quality parameters, while 1103P might be better choice under water-limiting conditions
Bernoulli type polynomials on Umbral Algebra
The aim of this paper is to investigate generating functions for modification
of the Milne-Thomson's polynomials, which are related to the Bernoulli
polynomials and the Hermite polynomials. By applying the Umbral algebra to
these generating functions, we provide to deriving identities for these
polynomials
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