• Natural Product Sciences
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• v.24 no.1
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• pp.71-78
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• 2018

The present study deals with the determination of optimal values of operating parameters such as the temperature of heating, the mass of the plant material and the volume of water leading to the best yield of electromagnetic induction (EMI) heating extraction of Algerian Thymus fontanesii essential oil. After an appropriate choice of the three critical variables, eight experiments leaded to a mathematical model as a first-degree polynomial presenting the response function (yield) in the relation to the operating parameters. From the retained model, we were able to calculate the average response, the different effects and their interactions. The maximum of essential oil recovery percentage relative to the initial mass of plant material was 1.69%, and was obtained at ($140^{\circ}C$, 250 g and 4.5 L). The chemical composition of the Algerian T. fontanesii essential oil under the obtained optimal conditions ($140^{\circ}C$, 250 g and 4.5 L), determined by GC/MS and GC/FID, reveled of the presence of major components such as: carvacrol ($70.6{\pm}0.1%$), followed by p-cymene ($8.2{\pm}0.2%$).

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.375-381
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• 2012

Two experiments were conducted to establish a digestible energy (DE) content prediction model of rapeseed meal for growing-finishing pig based on rapeseed meal's chemical composition. In experiment 1, observed linear relationships between the determined DE content of 22 rapeseed meal calibration samples and proximate nutrients, gross energy (GE) and neutral detergent fiber (NDF) were used to develop the DE prediction model. In experiment 2, 4 samples of rapeseed meal selected at random from the primary rapeseed growing regions of China were used for testing the accuracy of DE prediction models. The results indicated that the DE was negatively correlated with NDF (r = -0.86) and acid detergent fiber (ADF) (r = -0.73) contents, and moderately correlated with gross energy (GE; r = 0.56) content in rapeseed meal calibration samples. In contrast, no significant correlations were found for crude protein, ether extract, crude fiber and ash contents. According to the regression analysis, NDF or both NDF and GE were found to be useful for the DE prediction models. Two prediction models: DE = 16.775-0.147${\times}$NDF ($R^2$ = 0.73) and DE = 11.848-0.131${\times}$NDF+0.231${\times}$GE ($R^2$ = 0.76) were obtained. The maximum absolute difference between the in vivo DE determinations and the predicted DE values was 0.62 MJ/kg and the relative difference was 5.21%. Therefore, it was concluded that, for growing-finishing pigs, these two prediction models could be used to predict the DE content of rapeseed meal with acceptable accuracy.

• Mass Spectrometry Letters
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• v.5 no.4
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• pp.115-119
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• 2014

The Brazil nut (Bertholletia excelsa - Lecythidaceae) is considered a product with high economic value, being a food widely appreciated for its nutritional qualities. Although previous studies have reported the biochemical composition of Brazil nut oil, the knowledge regarding the phospholipid composition exhibits a disagreement: the composition of fatty acids present in the structures of phospholipids is reported as being different from the composition of the free fatty acids present in the oil. In this work, solid phase extraction (SPE) was employed to provide a fast extraction of the phospholipids from Brazil nuts, in order to compare the phospholipid profile of the in nature nuts and their fatty acids precursor present in the oil. The major phospholipids were characterized by mass spectrometry approach. Their fragmentation pattern through direct infusion electrospray ionization ion-trap tandem mass spectrometry ($ESI-IT-MS^2$) proved to be useful to unequivocal characterization of these substances. High resolution (HR) experiments through ESI using a quadruple time of flight mass spectrometry (QTOF) system were performed to reinforce the identifications.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.169-178
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• 2014

Samples of Clitoria ternatea L. (Cunh$\tilde{a}$) were harvested at 35, 50, 70, and 90 d after a uniformity harvest in a field study designed as a completely randomized design with a total of 18 experimental plots. The dry matter yield of the whole plant was separated quantitatively into leaves, stems, and pods at each harvesting age. Chemical analyses and in vitro gas production kinetics were performed to assess the quality of the plant parts. Yields, chemical composition, and estimates of gas production parameters were analyzed by fitting a mixed statistical model with two types of covariance structures as follows: variance components and an unrestricted structure with heterogeneous variances. Fast and slow gas yielding pools were detected for both leaves and stems, but only a single pool was detected for pods. The homoscedasticity assumption was more likely for all variables, except for some parameters of the gas production kinetics of leaves and stems. There was no presence of typical pods at 35 and 50 d. In the leaves, the fibrous fractions were affected, whereas the non-fibrous fractions were unaffected by the harvesting age. The harvesting age affected the majority of the chemical constituents and gas kinetic parameters related to the stems. The leaves of this legume were the least affected part by the aging process.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.83-84
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• 2006

Processing of W-Cu graded materials from attritor-milled W-CuO mixtures is described. The powder reduction steps are investigated by TG and XRD analyses and by microstructural observations (SEM, TEM). Sintering of reduced powder with different compositions is analysed by dilatometry. Sintering behaviour of the graded component processed by co-compaction of a 10/20/30wt%Cu multi-layer material is briefly discussed. Liquid Cu migration is observed and smooths the composition gradient. Perspectives to control this migration are discussed.

• Journal of the Korean Mathematical Society
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• v.41 no.1
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• pp.1-20
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• 2004

Let A be a uniform algebra, and let $\phi$ be a self-map of the spectrum $M_A$ of A that induces a composition operator $C_{\phi}$, on A. It is shown that the image of $M_A$ under some iterate ${\phi}^n$ of \phi is hyperbolically bounded if and only if \phi has a finite number of attracting cycles to which the iterates of $\phi$ converge. On the other hand, the image of the spectrum of A under $\phi$ is not hyperbolically bounded if and only if there is a subspace of $A^{**}$ "almost" isometric to ${\ell}_{\infty}$ on which ${C_{\phi}}^{**}$ "almost" an isometry. A corollary of these characterizations is that if $C_{\phi}$ is weakly compact, and if the spectrum of A is connected, then $\phi$ has a unique fixed point, to which the iterates of $\phi$ converge. The corresponding theorem for compact composition operators was proved in 1980 by H. Kamowitz [17].

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.929-932
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• 1993

A fuzzy microcontroller is presented implementing a simplified inference mechanism. Fuzzification, rule composition and defuzzification are carried out by means of (basically) analog current-mode CMOS circuits operating in strong inversion. Also a voltage interface is provided with the external world. Combining analog and digital techniques allow a programming capability.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.4-5
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• 2001

Advent of lasers offering high intensity beam has opened the glass to the nonlinear optic (NLO). The high electric field associated with such laser beams can be so large that high order components of the glass polarization can be measured. Such development is of scientific and technological interests in particular in systems involving an intensity-dependent refractive index and/or ultra-fast response (＜10$\^$-12/s). From a scientific viewpoint the NLO response intensity must be understood as a function of the glass composition. On the other hand, large family of applications are presently under investigation in various fields of optical materials or systems e.g. laser glasses for fusion energy, soliton propagation for ultra-long distances, ultra-fast-switching, optical storage etc....(omitted)

• Advances in materials Research
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• v.13 no.2
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• pp.141-151
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• 2024

The aim of this work was to determine the behavior of alloy elements and compounds formed during solidification in the manufacturing process of the CuAgZrCr alloy under an oxidizing environment. Bulk and surface analysis techniques, such as Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Raman and X-ray diffraction (XRD) were used to characterize the phases obtained in the solidification process. In order to focus the analysis on the on grain boundary interface, partial removal of the matrix phase by acid attack was performed. The compositional differences obtained by SEM-EDX, Raman and XPS on post-manufacturing materials allowed us to conclude that the composition of grain boundaries of the alloy is directly influenced by the oxidizing environment of alloy manufacturing.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.3
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• pp.63-74
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• 1999

In this paper we present a Hangul Encryption Algorithm (HEA) which encrypts composition Hangul syllables into composition Hangul syllables using the non-linear structure of Hangul. Since ciphertexts generated by HEA are displayable characters HEA can be used in applications such as Privacy Enhanced mail (PEM) where ciphertexts should be displayable characters. HEA is based on DES and it can be shown that HEA is as safe as DES against the exhaustive key search differential cryptanalysis and linear cryptanalysis. HEA also has randomness of phonemes of ciphertexts and satisfies plaintext-ciphetext avalanche effect and key-ciphertext avalanche effect.