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An exact solution has been obtained to the integral equation for the current in a frame antenna built with an infinitely narrow gap. The total current at the input is infinite because of the infinite capacity of the gap and the finite thickness of the antenna. 相似文献
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O Kalayci T Coskun A Tokatli E Demir G Erdem C Güng?r A Yükselen I Ozalp 《Canadian Metallurgical Quarterly》1994,124(1):103-104
Two patients with biotinidase deficiency had diagnoses of infantile spasms made at 1 month of age. Biotinidase deficiency may be seen early in the neonatal period without the characteristic findings such as alopecia and seborrheic dermatitis. This diagnosis should be considered in patients with infantile spasms. 相似文献
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Hidden Markov Models (HMM) are used to detect abnormal operation of dynamic processes and diagnose sensor and actuator faults. The method is illustrated by monitoring the operation of a pasteurization plant and diagnosing causes of abnormal operation. Process data collected under the influence of faults of different magnitude and duration in sensors and actuators are used to illustrate the use of HMM in the detection and diagnosis of process faults. Case studies with experimental data from a high‐temperature‐short‐time pasteurization system showed that HMM can diagnose the faults with certain characteristics such as fault duration and magnitude. 相似文献
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Gozde Gurdeniz Banu Ozen Figen Tokatli 《European Journal of Lipid Science and Technology》2010,112(2):218-226
The composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier‐transform infrared (FT‐IR) spectroscopy data in combination with chemometric methods were used to classify extra‐virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30 different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT‐IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils. 相似文献
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Differentiation of mixtures of monovarietal olive oils by mid‐infrared spectroscopy and chemometrics
Gozde Gurdeniz Figen Tokatli Banu Ozen 《European Journal of Lipid Science and Technology》2007,109(12):1194-1202
Fourier transform infrared (FT‐IR) spectroscopy in combination with chemometric techniques has become a useful tool for authenticity determination of extra‐virgin olive oils. Spectroscopic analysis of monovarietal extra‐virgin olive oils obtained from three different olive cultivars (Erkence, Ayvalik and Nizip) and mixtures (Erkence‐Nizip and Ayvalik‐Nizip) of monovarietal olive oils was performed with an FT‐IR spectrometer equipped with a ZnSe attenuated total reflection sample accessory and a deuterated tri‐glycine sulfate detector. Using spectral data, principal component analysis successfully classified each cultivar and differentiated the mixtures from pure monovarietal oils. Quantification of two different monovarietal oil mixtures (2–20%) is achieved using partial least square (PLS) regression models. Correlation coefficients (R2) of the proposed PLS regression models are 0.94 and 0.96 for the Erkence‐Nizip and Ayvalik‐Nizip mixtures, respectively. Cross‐validation was applied to check the goodness of fit for the PLS regression models, and R2 of the cross‐validation was determined as 0.84 and 0.91, respectively, for the two mixtures. 相似文献
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Fatty acid composition and mid-infrared spectra of olive oils in combination with chemometric techniques were used in the
classification of Turkish olive oils with respect to their varieties, growing location and harvest year. In particular, olive
oil samples belonging to five different cultivars were obtained from the same orchard in the middle part of Aegean region
and two of these varieties were also received from another orchard in northern part of the same region of Turkey in two consecutive
harvest years. Evaluation of nine different fatty acid compositions with principal component analysis revealed clear differentiation
with respect to variety, geographical origin and harvest year. On the other hand, mid-infrared spectra also achieved varietal
and seasonal discrimination to some extent, but differentiation is not as clear as that obtained using fatty acid compositions. 相似文献
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Permeation of CO2 and O2 through a low density polyethylene film was studied with CO2-N2 mixtures in the temperature range 263-283 K, and with CO2-O2-N2 mixtures in the range 257-313 K. The temperature dependence of the permeabilities of these gases agreed with the Arrhenius expression. The activation energy for carbon dioxide diffusion was between 3.53 × 104 and 3.74 × 104J/mol; the activation energy for oxygen diffusion was 3.13 × 104J/mol. The pre-exponential constant for oxygen was higher than that of carbon dioxide in various mixtures. It was also found that the pre-exponential constant of carbon dioxide decreased with increasing CO2 concentration in the mixtures. 相似文献
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Derya Alkan Figen Tokatli Banu Ozen 《Journal of the American Oil Chemists' Society》2012,89(2):261-268
The aim of this research was to characterize the extra virgin olive oil samples from different locations in the Aegean coastal
area of Turkey in terms of their phenolic compositions for two consecutive years to show the classification of oil samples
with respect to harvest year and geography. Forty seven commercial olive oil samples were analyzed with HPLC–DAD, and 17 phenolic
compounds were quantified. Hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, cinnamic acid, luteolin and apigenin were the characteristic phenols observed in all oil samples
for two harvest years. Syringic acid, vanillin and m-coumaric acid were the phenolic compounds appeared in the olive oil depending on the harvest year. Partial least square-discriminant
analysis (PLS-DA) of data revealed that oils from the north Aegean and south Aegean areas had different phenolic profiles.
The phenolic compounds, which played significant roles in the discrimination of the olive oils, were tyrosol, oleuropein aglycon,
cinnamic acid, apigenin and hydroxytyrosol to tyrosol ratio. The Aegean coastal region is the largest olive oil producer and
exporter of Turkey. This study shows that the olive oils from different parts of the region have their own defining characteristics
that can be used in the authentication studies and geographical labeling of Turkish olive oils. 相似文献