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101.
S. Wali Abdi 《School science and mathematics》1993,93(7):391-392
Book reviewed in this article: Educational Prospective for Science Technology and Society in Japan , Japan Society for Science Education All Natural Pogo , Norman F. Hale 相似文献
102.
103.
H. R. Monsef-Esfahani F. Karamkhani B. Nickavar K. Abdi M. A. Faramarzi 《Chemistry of Natural Compounds》2007,43(1):40-43
The chemical composition of the essential oils of Dracocephalum kotschyi (Lamiaceae) aerial parts, grown in Iran and obtained from three different methods, were determined by GC and GC/MS. Fifty-seven
compounds (93.3%) in the hydrodistillate oil, 55 compounds (94.2%) in the steam distillate oil, and 34 compounds (98.4%) in
the hydrolate were identified. The major compounds in the hydrodistillate oil were α-pinene (12.1%), methyl geranate (11.2%),
β-ocimene (8.6%), and limonene (7.2%). α-Pinene (15%), methyl geranate (14.5%), limonene (11.2%), and β-ocimene (8.4%) were
the most abundant components in the steam distillate oil. The percentages of geraniol (13%), trans-verbenol (11.6%), and terpinen-4-ol
(11.2%) were more than other constituents in the hydrolate.
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 35–37, January–February, 2007. 相似文献
104.
T Villén Y A Abdi O Ericsson L L Gustafsson F Sj?qvist 《Journal of chromatography. A》1990,529(2):309-317
Analytical methods for determining metrifonate and dichlorvos in whole blood and a sampling procedure suitable for pharmacokinetic studies in man are described. Metrifonate concentrations were determined after chloroform extraction using gas chromatography-nitrogen-phosphorus detection. The within-assay coefficients of variation were 4 and 9% at 19.4 and 0.8 mumol/l (limits of determination), respectively. Dichlorvos was determined using gas chromatography-mass spectrometry of toluene extracts. The within-assay coefficients of variation were 2 and 5% at 225 and 50 nmol/l (limits of determination), respectively. Since both substances are chemically unstable, the blood was collected by dripping it directly from the vein into 0.74 M phosphoric acid. 相似文献
105.
M. R. Abdi H. Faghihian M. Mostajaboddavati A. Hasanzadeh M. Kamali 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(2):319-324
Summary A reconnaissance study has been made on the distribution of 238U, 232 Th, 40K, 137Cs and geochemical features in soil and sediment samples at various locations in the coast of Persian Gulf. Activity concentration
levels due to radionuclides were measured in 50 samples of soils and sediments collected from the coast of Hormozgan. From
the measured spectra, activity concentrations were determined for 40K (range from 140 to 1172 Bq . kg-1), 137Cs (from 0 to 15 Bq . kg-1), 238 U (from 29 to 385 Bq . kg-1) and 2321 Th (from 9 to 156 Bq . kg-1) with the lowest limit of detection (LLD) of 68, 3.2, 4.3 and 4.3 Bq . kg-1, respectively. The dose rate from ambient air at the soil ranges was between 23 to 177 nGy . h-1 with an average of 60±7.86 nGy . h-1. 相似文献
106.
Stéphanie Bougeard Hervé Abdi Gilbert Saporta Ndèye Niang 《Advances in Data Analysis and Classification》2018,12(2):285-313
Multiblock component methods are applied to data sets for which several blocks of variables are measured on a same set of observations with the goal to analyze the relationships between these blocks of variables. In this article, we focus on multiblock component methods that integrate the information found in several blocks of explanatory variables in order to describe and explain one set of dependent variables. In the following, multiblock PLS and multiblock redundancy analysis are chosen, as particular cases of multiblock component methods when one set of variables is explained by a set of predictor variables that is organized into blocks. Because these multiblock techniques assume that the observations come from a homogeneous population they will provide suboptimal results when the observations actually come from different populations. A strategy to palliate this problem—presented in this article—is to use a technique such as clusterwise regression in order to identify homogeneous clusters of observations. This approach creates two new methods that provide clusters that have their own sets of regression coefficients. This combination of clustering and regression improves the overall quality of the prediction and facilitates the interpretation. In addition, the minimization of a well-defined criterion—by means of a sequential algorithm—ensures that the algorithm converges monotonously. Finally, the proposed method is distribution-free and can be used when the explanatory variables outnumber the observations within clusters. The proposed clusterwise multiblock methods are illustrated with of a simulation study and a (simulated) example from marketing. 相似文献
107.
Tayebeh Asadi Nader Rahimi Kakavandi Amir Nili Ahmadabadi Ali Heshmati Akram Ranjbar Khosrou Abdi Maryam Ezoddin 《Biomedical chromatography : BMC》2022,36(5):e5304
An effervescent tablet-assisted switchable polarity solvent–based homogeneous liquid-phase microextraction combined with gas chromatography with flame ionization detection has been conducted for the separation, preconcentration, and detection of permethrin and deltamethrin in the river water specimens. Triethylamine (TEA) was utilized as the switchable polarity solvent in this method. The switching process was carried out by the dissolution of an effervescent tablet including an effervescency agent (sodium carbonate) and a proton donor agent (citric acid). Changing the pH of the specimen solution enhanced the conversion of TEA into protonated triethylamine carbonate through the tablet that generated carbon dioxide bubbles in situ. Finally, the addition of sodium hydroxide changed the ionization state of TEA and separated the two phases. Influential factors in the extraction were investigated. According to optimal situations, the limit of detection and the limit of quantification were 0.16 and 0.5 μg L−1 for permethrin and 0.03 and 0.1 μg L−1 for deltamethrin, respectively. The preconcentration factor was 194 in river water samples and inter- and intra-day precision (relative standard deviation %; n = 5) was <5%. The extraction recovery was obtained in the range of 93.0%–97% for permethrin and deltamethrin in water samples. 相似文献
108.
R. El Abdi A. Rujinski M. Poulain Irina Severin 《Optics and Lasers in Engineering》2009,47(5):519-526
Silica optical fibers that were developed for telecommunication networks are now being used for sensors and smart structures. Their reliability and expected lifetime has appeared as a major concern. A series of experiments were implemented in order to assess aging fiber under microwave and X-ray radiation and under mechanical stress. Optical fibers were aged in water under controlled stress overlapping microwave energy for different durations or to X-ray radiation for different voltages, currents and exposure times. Fiber samples were wound onto different diameter mandrels applying, consequently, a non-uniform tensile and compression stress in function with the fiber diameter. In certain cases and testing conditions, a comparison with received fibers revealed an increase in fiber strength with a generally mono-modal defect distribution on the fiber surface. 相似文献
109.
110.