Mine operating accurate stability control with optical fibersensing and Bragg grating technology: the European BRITE/EURAM STABILOSproject

Recent developments of stability control in mines, essentially based on Ge-doped fiber Bragg gratings (FBG) are reported including results about the different aspects of the system: accurate characterizations of FBG, sensor network topology and multiplexing method, user interface design and sensor packaging     

Methods for the determination of cyclopropenoid fatty acids. VII. The dilution-HBr-titration technique as a general method

The stepwise HBr titration method for the cyclopropenoid analysis of cottonseed oils is subject to serious inaccuracies when applied to samples containing higher cyclopropenoid concentrations, particularly if they contain appreciable amounts of alumina-adsorbable materials. A modification of the method is described which eliminates these sources of error. Its validity has been established by the analysis of a wide range of synthetic compositions including compositions containing massive amounts of interfering HBr-reactive substances and other alumina-adsorbable materials. The method with further modification can be used to analyze glycerides with the same high degree of accuracy. Presented at the AOCS Meeting in Houston, April 1965. So. Utiliz. Res. Dev. Div., ARS, USDA.     

Preparation and characterization of a number of amine salts of long-chain fatty acids

Summary Eighty-eight amine salts of long-chain fatty acids have been prepared, purified by solvent crystallization, and characterized. Forty-five of these were salts of palmitic acid. The rest included salts of capric, lauric, myristic, stearic, oleic, elaidic, and 12-hydroxystearic acids. A variety of aliphatic, aromatic, and heterocyclic amines, including primary, secondary, and tertiary amines, were investigated. The majority of these gave 1∶1 acid-amine compounds on solvent recrystallization of an equimolar mixture of acid and amine. Some of the amines gave no crystallizable salt, and with others the pure salt could not be obtained by this procedure. Under the same conditions the symmetrical alkyl, substituted alkyl, and aralkyl secondary amines investigated gave crystallizable compounds containg two molecules of fatty acid to one of amine. Molecular compounds of 2-aminopyridine with four molecules of saturated fatty acid were formed by recrystallization starting with a 1 to 4 amine-acid mixture. Surface-tension measurements were made for aqueous solutions of a few of the amine salts. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Fatty acid morpholides as plasticizers for vinyl chloride resins. III. Ternary compatibility-composition diagrams for the oleic-linoleic-stearic and oleic-linoleic-palmitic systems

A systematic investigation has been made of the effect of fatty acid composition on the compatibility of the corresponding mixed morpholides as plasticizers for vinyl chloride-vinyl acetate copolymer resins. Plasticizer evaluation data were obtained for the morpholides of lauric, palmitic, elaidic, and epoxyoleic acids and compared with the literature values for other fatty acid morpholides and morpholide mixtures. Ternary compatibility-composition diagrams have been constructured for the oleic-linoleic-stearic and the oleic-linoleic-palmitic morpholide systems. These diagrams make it possible to predict what adjustment, if any, must be made in the composition of any mixture of these fatty acids so that the corresponding morpholide mixture will be compatible. The diagrams will be useful in selecting the most appropriate and economical fatty acid sources from which to make compatible morpholide mixtures. Presented at the 52nd Annual Meeting, American Oil Chemists’ Society, St. Louis, Mo., May 1–3, 1961. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed.The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape.By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view.     

Predicting proteinase specificities from free energy calculations

The role of the primary binding residue (P1) in complexes between three different subtilases (subtilisin Carlsberg, thermitase and proteinase K) and their canonical protein inhibitor eglin c have been studied by free energy calculations. Based on the crystal structures of eglin c in complex with subtilisin Carlsberg and thermitase, and a homology model of the eglin c-proteinase K complex, a total of 57 mutants have been constructed and docked into their host proteins. The binding free energy was then calculated using molecular dynamics (MD) simulations combined with the linear interaction energy (LIE) method for all complexes differing only in the nature of the amino acid at the P1 position. LIE calculations for 19 different complexes for each subtilase were thus carried out excluding proline. The effects of substitutions at the P1 position on the binding free energies are found to be very large, and positively charged residues (Arg, Lys and His) are particularly deleterious for all three enzymes. The charged variants of the acidic side chains are found to bind more favorably as compared to their protonated states in all three subtilases. Furthermore, hydrophobic amino acids are accommodated most favorably at the S1-site in all three enzymes. Comparison of the three series of binding free energies shows only minor differences in the 19 computed relative binding free energies among these subtilases. This is further reflected in the correlation coefficient between the 23 relative binding free energies obtained, including the possible protonation states of ionizable side chains, but excluding the P1 Pro, for subtilisin Carlsberg versus thermitase (0.95), subtilisin versus proteinase K (0.94) and thermitase versus proteinase K (0.96).     

Ride comfort optimization of a city bus

Ride comfort optimization of a city bus is considered in this article, using stiffness and related damping of the power unit mounts as design variables. The response of the bus, due to road irregularities, is calculated in the time domain by using a finite element (FE) model describing the complete vehicle. The body of the bus is condensed, using a substructuring technique, in order to reduce the simulation times. Operational deflection shapes (ODS) have been used to compare measured and calculated vibrations and some corrections of the FE model have been done. The response, i.e. acceleration, at three locations in the bus has been frequency-weighted according to the comfort standard ISO 2631:1997. The resulting root mean square (RMS) values of these responses are then used in the objective functions in the optimization procedure. The computational results show that it is possible to increase the ride comfort. However, the improvement of the ride comfort is probably too small to have a substantial subjective impact on the passenger in the bus. The results show that the objective function, regarding the overall ride comfort in the bus, has local optima. Received October 10, 1999     

Interfacial Tension; a Stabilizing Factor for Janus Emulsions of Silicone Bixa Orellana Oils

The destabilization process was investigated for a Janus emulsion of silicone and Bixa Orellana oils stabilized by polyoxyethylene sorbitan monooleate (Tw 80) and carboxymethyl cellulose. The emulsion stabilized with Tw 80 showed significant and fast creaming, a process that was prevented by the addition of the polymer. During the extensive coalescence of the emulsions stabilized by Tw 80, the Janus topology was retained for months of storage until, finally, separation of the oils occurred. This result strongly indicates an unexpected stabilizing action of the i nterfacial free energy. This conclusion was supported by a calculation for a realistic model system of the interfacial energy difference between two cases of coalescence. In the first case, the two coalescing Janus drops united into a larger Janus drop, while in the second case two drops formed, each with only one oil. The first case gave a spontaneous reaction (reduced interfacial energy), while the second one meant an increase of energy, i.e. it cannot happen without adding energy. The authors are aware that this stabilization is a new phenomenon in emulsion science with potential ramifications in future emulsion technology. However, it is essential to realize that the stabilization is of temporary occurrence in the destabilization process, and the free energy to give a final emulsion state with separated oils is overwhelmingly dominant. In short, Janus emulsions will, in the end, separate into layers of the liquids, like all emulsions.     

Phase structural analyses of polyethylene coatings on high‐density papers. III. Determination of the crystallite thicknesses by T1 measurements

Two different extrusion‐coating qualities of polyethylene, namely LDPE and HDPE, were coated on high‐density papers. Differences were observed with respect to their response to storage and low temperature heat treatment. HDPE does not respond to storage at ambient temperature and heat treatment in the same way as LDPE. The LDPE‐coating exhibits an increase in the monoclinic crystalline fraction at the paper surface as a result of heat treatment. The nature of this response appears to be a result of adhesion to a paper surface, the properties of this surface, orientation of polymer chains, and chain mobility differences. The increase of the monoclinic fraction is shown to relate to an increase of the mean crystallite thickness and initiation of new crystallites at the paper surface. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 235–241, 2004