Infrared and Structural Properties of Y1−xNdxBa2Cu3O7−δ (0 ≤ x ≤ 1)

Infrared and structural properties of Y_1?x Nd _x Ba₂Cu₃O_7?δ (0 ≤ x ≤ 1) were investigated using infrared absorption spectroscopy and X-ray powder diffraction. The unit cell parameters of the samples were defined using X-ray diffraction data. The resistance measurements showed that the samples revealed superconductivity in the temperature range of 80–100 K. It was observed that by the substitution of Nd to Y in YBa₂Cu₃O_{7 ? δ} IR band at 573 cm^?1 that is assigned as Cu–O axial antisymmetric stretching mode shifts to 533 cm^?1 while the band at 620 cm^?1 that is due to Cu–O symmetric stretching mode in YBa₂Cu₃O_7?δ shifts to 588 cm^?1.     

A Current-Mode Logic for Low-Voltage, High-Speed Mixed-Mode VLSI Circuits

A wired-AND current-mode logic (WCML) circuit is designed for high performance mixed analog and digital system designs on a common silicon substrate, using standard CMOS process. Current is used for digital information carrier in order to be able to reduce supply voltage, power consumption, digital switching noise and to increase operating frequency. The WCML circuit uses current-steering technique. It is composed of a simple current mirror with a current injector. Wired-AND connections cause the logic circuit to operate as a NAND logic gate which provides to implement any boolean function. High-speed is achieved by varying the injection current level even at low-voltage supply (<1.5 V) with low-power consumption.     

Fracture path prediction of diamond segment in a marble cutting disc

This study investigates the fracture path behaviour of diamond segments that have been brazed on a marble cutting disc. The segments are braze‐joined using the oxy‐gas welding technique. The micro‐structure of the brazing zone and the disc were investigated using standard metallographic techniques and scanning electron microscope (SEM). Additionally, we used numerical modelling to study crack growth at the welding zone. Two dimensional linear elastic fracture mechanics principles were used to analyze propagation behaviour of the crack. Stress intensity factors were calculated using displacement correlation method. It was deduced from the SEM analysis of the fractured segment surface that the fracture occurred in the diamond segment due to stress concentration near the sharp corners of the diamond particles that are embedded into the matrix. The existence of such sharp artefacts within the matrix leads to the formation of cracks.     

A modification to temperature-composition pdf method and its application to the simulation of a transitional bluff-body flame

This study proposes a modification to the temperature-composition pdf approach. Instead of equilibrium mass fractions, values of a time-varying homogeneous reacting system are used in the simplification of the joint-pdf into the multiplication of marginal pdfs. The approach takes into consideration of local time scales which are defined on the basis of energy balance with two competing transport mechanisms on the flame surface; these are the turbulent convective transport perpendicular to the flame and the diffusive flux tangent to the flame. The flame surface and flux directions are described by the gradient of mixture fraction and unitary tangent vector which is defined by the scalars. The new approach in combination with the ILDM chemistry is used in the numerical simulation of a transitional bluff-body flame. Despite the use of simple pdf models, the present formulation appears to be very successful in predicting the flow field, the temperature and progress variables and, except for the mixture fraction, show relatively good agreement with the experimental data. The profiles of the time scale show that the flame develops in relation to the distributions of progress variables in the $\mathit{T}?\xi$ parameter space. Hence, the approach offers the possibility of local flame extinction. It also gives a rational explanation of the bimodal distributions of the reactive scalar pdfs in a turbulent flow with fluctuations of a wide spectrum of scales.     

A new hybrid approach based on SARIMA and partial high order bivariate fuzzy time series forecasting model

In the literature, there have been many studies using fuzzy time series for the purpose of forecasting. The most studied model is the first order fuzzy time series model. In this model, an observation of fuzzy time series is obtained by using the previous observation. In other words, only the first lagged variable is used when constructing the first order fuzzy time series model. Therefore, this model can not be sufficient for some time series such as seasonal time series which is an important class in time series models. Besides, the time series encountered in real life have not only autoregressive (AR) structure but also moving average (MA) structure. The fuzzy time series models available in the literature are AR structured and are not appropriate for MA structured time series. In this paper, a hybrid approach is proposed in order to analyze seasonal fuzzy time series. The proposed hybrid approach is based on partial high order bivariate fuzzy time series forecasting model which is first introduced in this paper. The order of this model is determined by utilizing Box-Jenkins method. In order to show the efficiency of the proposed hybrid method, real time series are analyzed with this method. The results obtained from the proposed method are compared with the other methods. As a result, it is observed that more accurate results are obtained from the proposed hybrid method.     

Chemical Compositions and Mineral Contents of Some Hull-Less Pumpkin Seed and Oils

The main objective of this study was to determine total oil, total phenol, antioxidant activity and mineral contents of hull‐less pumpkin seeds and also fatty acid composition of seed oils. The results indicated that total oil, total phenol content and antioxidant activity values were found between 33.04 and 46.97 %, 56.94 and 87.15 mg GAE/100 g and 0.19 and 11.75 %, respectively (p < 0.05). Linoleic, oleic, palmitic and stearic acids were the most prominent fatty acids in all genotypes. The most abundant mineral in the studied seeds, which belong to different genotypes, was potassium (2704.75–1033.63 ppm) followed by phosphorus (3569.690–9108.835 ppm) and magnesium (1275.15–3938.16 ppm) (p < 0.05). Particularly genotype‐1 was the richest seed in essential fatty acids and minerals.     

The effect of ultrasound-vacuum-assisted extraction on bioactive properties of pitaya (Hylocereus undatus)

This study aimed to investigate the effect of ultrasound-assisted extraction under vacuum on bioactive properties of peel and flesh of pitaya fruit, and also compare with sonication under atmosphere condition using the principal component analysis (PCA). Vacuum sonication exhibited better results for total phenolic (56.78–71.54 mg GAE per 100 g for peel; 11.03–17.92 mg GAE per 100 g for flesh) and total flavonoid (95.33–115.71 mg QE per 100 g for peel; 13.26–19.36 mg QE per 100 g for flesh) amounts. DPPH free radical scavenging activity values of peel and flesh increased from 1.97 to 2.53 mmol TE kg^-1; from 0.33 to 0.50 mmol TE kg^-1 after sonication process, respectively. The main phenolic compounds of pitaya were identified as catechin (1.15–20.31 mg per 100 g) and rutin (0.88–14.55 mg per 100 g) in peel; catechin (1.11–9.35 mg per 100 g) and 3,4-dihydroxybenzoic acid (1.29–3.60 mg per 100 g) in flesh. The combination of vacuum and ultrasound process can be used as a green extraction technology in order to enhance the amounts of bioactive compounds of pitaya fruit.     

A new approach for determining the length of intervals for fuzzy time series

In the implementations of fuzzy time series forecasting, the identification of interval lengths has an important impact on the performance of the procedure. However, the interval length has been chosen arbitrarily in many papers. Huarng developed a new approach which is called ratio-based lengths of intervals in order to identify the length of intervals. In our paper, we propose a new approach which uses a single-variable constrained optimization to determine the ratio for the length of intervals. The proposed approach is applied to the two well-known time series, which are enrollment data at The University of Alabama and inventory demand data. The obtained results are compared to those of other methods. The proposed method produces more accurate predictions for the future values of used time series.