Determination of fatty acid composition by gas chromatography: I. Analysis with use of thermal conductivity detector

For the purpose of establishing a standard method for the gas chromatographic determination of fatty acid composition, a collaborative study team has carried out replicate analyses of specified samples using gas chromatographs equipped with thermal conductivity detectors and has examined the entire set of experimental data by a statistical method. From the results of the four collaborative works it was found that deviation of analytical values from exact composition and interlaboratory scattering of data may be considerably decreased by the following means: (a) enlarging the size of narrow peaks (less than 5 mm at a half height) or peaks with low height by adjusting the attenuator range or chart speed; (b) correcting the analytical values by using correction factors determined from analysis of known mixtures having composition similar to that of an unknown sample. Presented at the JOCS-AOCS Joint Meeting, Los Angeles, April 1972.     

Investigation on Static Stability of Sheet Pile Quay Wall Improved by Cement Treated Sea-Side Ground from Centrifuge Model Tests

The static stability of sheet pile quay walls on a thick clay deposit against horizontal loads was studied through a series of centrifuge model tests. In the tests, an overconsolidated Kaolin clay layer was prepared over a layer of dense Toyoura sand in a rectangular container. The model quay wall was set to the bottom of the sand layer. The sea-side area adjacent to the quay wall was improved with cement-treated Kawasaki clay. Under 50 g centrifugal acceleration, the clay deposit was consolidated and horizontal line loads of about 0 to 70 kN/m were applied to the quay wall. The width and the depth of the improved area were varied and its performance was compared with that of a quay wall embedded in unimproved ground. Results of the study indicated that the improved ground provided significant resistance against horizontal loading. In addition, a numerical model to estimate the mechanical behavior of the sheet pile quay wall is presented. The outcomes of the numerical model show good agreement with the centrifuge test results.     

Emotype: Expressing emotions by changing typeface in mobile messenger texting

Multimedia Tools and Applications - Instant messaging is a popular form of text-based communication. However, text-based messaging lacks the ability to communicate nonverbal information such as...     

Direct Formation of Mg–Al-Layered Double-Hydroxide Films on Glass Substrate by the Sol–Gel Method With Hot Water Treatment

Amorphous Al₂O₃–MgO thin films with an Mg/Al ratio of unity were prepared on glass substrates by the sol–gel method with a heat treatment at 300°C for 30 min. By immersing the films in water containing sodium hydroxide (pH 10–13) at 100°C, nano-crystals of Mg–Al-layered double hydroxide (LDH) with a hexagonal structure, which is called hydrotalcite and the most basic composition of LDH, were precipitated on the amorphous Al₂O₃–MgO films. The maximum amount of Mg–Al nanocrystals was obtained when the film was immersed in basic solution of pH 12.     

Degradation of azo dyes by cell-free extract from Aeromonas hydrophila var. 24B

The degradation of several azo dyes by cell-free extract from Aeromonas hydrophila var. 24B has been studied. The compounds 4-dimethylaminoazobenzene, 4-diethylaminoazobenzene, 2′-carboxy-4-dimethylaminoazo-benzene, 2′-carboxy-4-diethylaminoazobenzene, 4′-carboxy-4-dimethylaminoazobenzene, and 2′-methoxy-carbonyl-4-dimethylaminoazobenzene were appreciably degraded by the cell-free extract. Azobenzene and 4-carboxyazobenzene were not degraded. Aniline was detected by gas chromatography-mass spectrometry as a degradation product from 4-aminoazobenzene and 4-dimethylaminoazobenzene. 4-DimethyIaminoaniline was detected by gas chromatography-mass spectrometry and spectrophotofluorimetry as a degradation product from 2′-carboxy-4-dimethylaminoazobenzene. The cell-free extract had high substrate specificity for 2′-carboxy-4-dimethylaminoazobenzene.     

Deposition and Analysis of Al‐Rich c‐AlxTi1−xN Coating with Preferred Orientation

Metastable c‐Al_xT_1?xN is an important and well‐established hard coating in the tool industry. To improve the mechanical and thermal properties, Al‐rich c‐Al_xTi_1?xN coatings with controllable preferred crystal orientations were fabricated via low‐pressure chemical vapor deposition (LP‐CVD) in an industrial plant, using an AlCl₃–TiCl₄–NH₃–Ar–H₂ precursor system. The c‐Al_xTi_1?xN coatings with (100)‐ and (111)‐preferred orientations and average x values of 0.82 and 0.73, respectively, comprised c‐Al(Ti)N/c‐Ti(Al)N nanolamellae with average compositions of c‐Al_0.9Ti_0.1N/c‐Al_0.6Ti_0.4N and c‐Al_0.80Ti_0.20N/c‐Al_0.50Ti_0.50N; the average lamellar periods were 7.7 and 4.5 nm, respectively. High‐resolution transmission electron microscopy indicated that the c‐Al(Ti)N/c‐Ti(Al)N nanolamellae were modulated along the <100> direction, implying coherent spinodal decomposition of c‐Al_xTi_1?xN in the as‐deposited state. The hardness of the c‐Al_xTi_1?xN coatings varied from 33 to 36 GPa, depending on the (100)‐ or (111)‐preferred orientation. Residual stress measurements in the as‐deposited state showed tensile stress values of 1.8 and 4.6 GPa for the (100)‐ and (111)‐oriented c‐Al_xT_1?xN coatings, respectively. This stress may be generated by the difference in the thermal expansion coefficient of the c‐Al_xT_1?xN coating and the carbide substrate and by coherency stress in the c‐Al(Ti)N/c‐Ti(Al)N nanolamellae. In situ high‐temperature X‐Ray diffraction results revealed high thermal stability up to 1000°C.     

Catalytic growth of carbon nanofilament in liquid hydrocarbon

Carbon nanofilaments were grown on silicon substrates by using a novel catalytic method in an organic liquid hydrocarbon. Nonequilibrium catalytic deposition gave significantly pure carbon nanofilaments with very little soot within a few minutes in n-octane. Scanning electron microscope images indicate that the nanofilaments are grown perpendicular to the Si substrate surface. This very rapid and dense production of carbon nanofilaments can be attributed to the great difference of chemical potential between the substrate surface and reactant liquid.     

Dehydrogenation of isopropylbenzene with vanadium-oxide-loaded activated carbon catalyst in the presence of carbon dioxide

Dehydrogenation of isopropylbenzene to α-methylstyrene was carried out using various supported metal oxide catalysts in the presence of carbon dioxide. An activated carbon-supported vanadium oxide catalyst afforded a high activity in carbon dioxide atmosphere: the α-methylstyrene yield in carbon dioxide atmosphere was two times greater than that in an argon atmosphere at 723 K. In order to investigate the role of carbon dioxide in this reaction, we carried out temperature-programmed reduction (TPR) studies using both fresh and used catalysts. The TPR profiles clearly indicate that carbon dioxide could keep the surface of vanadium oxide at a high oxidation state. This revised version was published online in July 2006 with corrections to the Cover Date.