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The Scheffe design was applied to a ternary mixture of 4,4′-diethoxy-2,2′-dihydroxy-α,α-dimethylbenzalazine, 4,4′-dipropoxy-2,2′-dihydroxy-α,α'-dimethylbenzalazine and 4,4′-dibutoxy-2,2′-dihydroxy-α,α-dimethylbenzalazine in order to improve the physical properties of each individual component. Twenty-two different mixtures were selected and their thermodynamical properties measured. A third order model was chosen to account for the experimental measurements. Thus, it was possible to determine the best region in the ternary diagram.

Some spiro[indoline-naphthoxazines] I and spiro[indoline-pyridobenzoxazines] II substituted by different groups were synthesized in order to evaluate their photochromic properties1 and to optimize the preparation of spiroheterocyclic systems. In addition, some spiro[indoline-naphthopyrans] III were also prepared as reference compounds. Their physical and spectroscopic characteristics (UV, 1H and 13C NMR) were determined. A study using the experimental design methodology allowed to point out the most important factors for improving the reaction yields.

Binary, ternary and quaternary mixtures of four smectogenic compounds: 4,4′-didecyloxy-2,2′-dihydroxybenzalazine, S-4′-decyloxy-2-hydroxy-4-(2-methylbutoxy)-α,α′-dimethylbenzalazine, 4,4′-didodecyloxy-2,2′-dihydroxy-α,α′-dimethylbenzalazine and 2-hydroxy-4,4′-dinonyloxy-α,α'-dimethylbenzalazine were studied. These systems of mixture were studied using the Scheffe algorithm which had proved to be particularly useful in the study of these types of mixture. Induction of chirality in a SC phase by mixture with compounds optically active was studied. Numerous transition solid-solid in mixtures during the melting were obtained and their repetition was verified.

This study examined the hypotheses that positive mood enhances conformity and that negative mood reduces it. Participants were induced to feel positive, neutral, or negative moods and then answered, in private, six mathematical questions. They observed that wrong answers were unanimously given by five bogus participants for three of the questions. Conformity was measured by whether they indicated the erroneous answers given by these bogus participants in these three questions. The results were supportive of the hypothesis. The current results are consistent with past findings about mood differences in heuristic versus elaborative processing. Copyright © 2007 John Wiley & Sons, Ltd.

This paper reports the synthesis of tetragonal zirconia nanowires using template method. An as-prepared sample was characterized by scanning and transmission electron microscopy. It was found that the as-prepared materials were tetragonal zirconia nanowires with average diameters of ca. 80 nm and length of over 10 μm. The Raman spectrum showed peaks at 120, 461, and 629 cm–1, which are attributed to the Eg, Eg, and B1g phonon modes of the tetragonal zirconia structure, respectively. The UV-vis absorption spectrum showed an absorption peak at 232.5 nm (5.33 eV in photon energy). Photoluminescence (PL) spectra of zirconia nanowires showed a strong emission peak at ca. 388 nm at room temperature, which is attributed to the ionized oxygen vacancy in the zirconia nanowires system.

We used an experimental design (Scheffe simplex-centroid design) to examine ingredient interactions in food protein mixtures and their effects on functional properties. A defined and limited number of milk, albumen, and egg yolk blends were made and evaluated for heat gelation properties and for emulsifying and foaming capacity and stability. The method accounted for nonlinear interactions between the ingredients. Synergistic effects were revealed on heat gelation and emulsifying properties but antagonistic effects for foaming properties were noted.

Treatment of C57BL/6J mice with an epoxide, glycidyl 1-naphthyl ether (GNE), resulted in an average of a 3.4-fold increase in frequency of 6-thioguanine-resistant mutants of mouse spleen T-lymphocytes. In similar experiments with the epoxide trichloropropylene oxide, no increase in mutant frequency was found. To determine the kind and location of mutations in the coding region of the hypoxanthine phosphoribosyl transferase (HPRT) gene, 26 GNE-induced mutants and 17 spontaneous mutants were analyzed by direct sequencing of polymerase chain reaction amplified cDNA. Among the GNE-induced mutants, HPRT cDNA was present in 22, while that from 4 could not be detected. Among the spontaneous mutants, HPRT cDNA was present in 15 and absent in 2. Among GNE-induced mutants, base substitution in HPRT occurred in 15 of 22 mutants analyzed. Nine of 15 base substitutions involved TA base pairs, primarily TACG transitions. Base substitutions were found throughout exons 3–7 but 46% of substitutions were located in exon 3 and one frameshift mutation involving a GC base pair in exon 3 was also observed. Among the spontaneous mutants, base substitutions of HPRT occurred in 7 of 15 mutants analyzed with 6 of 7 base substitutions involving a TA base pair and another 2 of the 15 mutants showed a 4 base pair deletion. The base substitution spectrum in GNE-induced mutants was different from that of the spontaneous mutants. © 1993 Wiley-Liss, Inc.

We present a full- ¤ ector Maxwell equation sol ¤ er for theanalysis of ¤ ertical-ca ¤ ity surface-emitting lasers VCSELs with circular()symmetry using the finite-difference time-domain FDTD method. We()apply this model to the air-post index-guided 1.55 m m VCSEL structure,and determine the resonant wa ¤ elengths and the quality factor forselected lowest order modes. The results of this study enable quantitati ¤ eand qualitati ¤ e descriptions of the trans erse-mode competition andemission spectra of VCSELs. Q 1998 John Wiley & Sons, Inc.Microwave Opt Technol Lett 18: 385]387, 1998. Key words: electromagnetic field sol ¤ er; finite-difference time-domainmethods; ¤ ertical-ca ity lasers Vertical-cavity surface-emitting lasers VCSELs demonstrate .many properties desirable for optical communications andinterconnects, such as low-beam divergence and single-modeoperation which result in superior coupling efficiency intosingle-mode fibers 1 , the possibility of wafer-level testing,wxand ease for two-dimensional array fabrication 2 . In manywxapplications, and for long-haul optical communications, inparticular, single-transverse-mode operation is desired. Forthis reason, a number of theoretical analyses have beenrecently reported in an attempt to understand the transverse-mode competition and the emission spectra of these lasers.The scalar beam-propagation 4 and the effective index 5wx wxmethods have been successfully used, but since they neglectthe vector nature of the electromagnetic field, these methodsare unable to model the full transverse-mode spectrum ofthese lasers. The transverse modes of vertical-cavity lasersare rather complicated, while their spatial shape and polar-ization properties depend on the type of mode definitionscheme. Index-guided, gain-guided, and oxide-apertured lasersshow distinctly different transverse modes and their depen-dence on injection current 6, 7 . Because these cavities arewxsmall on the order of a few wavelengths in all directions , the .application of beam-propagation methods and effective-indexmethods is unable to provide a sufficiently accurate descrip-tion of the optical field in the cavity. Moreover, the beam-propagation method does not account for multiple reflectionsin quarter-wave mirrors. Particularly difficult structures tomodel are the index-guided air-post devices and the oxide-apertured devices in which the large lateral refractive indexvariations severely add to the complexity of the problem 8 .wxFor this reason, it is necessary to include the vector nature ofthe electromagnetic field to accurately analyze vertical-cavitylasers. In this paper, we present an analysis of the passivecavity of a 1.55 mm air-post index-guided VCSEL using afull-vector finite-difference time-domain FDTD method. .The analyzed VCSEL structure is a 1550 nm double-fusedcavity that consists of an InGaAsP cavity sandwiched betweentwo AlGaAs AlGaAs .rGaAs quarter-wavelength distributedBragg reflectors DBR . A detailed description and the physi- .cal and optical structure parameters of this device are givenin 9 , while the simplified structure is shown in Figure 1 a .wx .The transverse modes of this resonator are determined byindex guiding in the top mirror, while the cavity loss occursdue to diffraction of the wave in the unguided sections of theactive layer and the bottom mirror. In a high-quality res-onator, such as the VCSEL, one may assume that the modesare not significantly perturbed by free-space propagation, andthe approximate cavity spectrum may be obtained by model-ing the VCSEL as a perfect cylindrical dielectric resonatorwx10 . However, this model does not provide the quality factorof each individual mode, namely, the discrimination betweenthe modes. For this purpose, one has to resort to a moreinvolved analysis: we use a full-vector finite-difference time-domain FDTD applicable to cylindrical high-quality open .resonators with dielectric andror metal boundaries. The pro-gram is used to determine the resonance wavelengths, thequality factor, and the mode spatial distribution for selectlowest order modes in the VCSEL cavity.The principle of operation of the FDTD program is basedon determining the passive-resonator temporal response tonarrowband noise delivered by an antenna source within thecavity. The resonator temporal response, detected at several

A methodological approach was used to optimize experimental conditions leading to complete saponification of cod liver oil without loss of polyunsaturated fatty acids. Each experiment, using conditions imposed by a Doehlert design, was analyzed for the percentages of fatty acids with different chain lengths and degrees of unsaturation: Y1=%C22:6ω3, Y2=%C20:5ω3, Y3=%C18:4ω3, Y4=%C18:1ω9+ω7, Y5=%C16:0. The difference between values obtained in each experiment and values obtained by transesterification allowed the extent of fatty acid degradation to be quantified. The experimental results were expressed by response surfaces allowing the choice of saponification conditions for each type of fatty acid. An optimum zone for saponification was observed which was larger when carried out under nitrogen. Nitrogen did not eliminate degradation, but degradation was less marked under nitrogen than under air. The fatty acid having the greatest degree of unsaturation in this study, C22:6ω3, was the first to be degraded. The extension of the Doehlert design to four factors showed that under air, alkali concentration and reaction time were the major factors governing loss of polyunsaturated fatty acids.

The use of modern methods of building optimal experimental matrices is especially suitable for optimization of properties of polymeric compound mixtures. We show how, with a limited number of well defined experiments, we optimized rheological properties of a mixture of a lauryl acrylate-stearyl methacrylate based copolymer and a resinic ester. The methodology is founded upon the determination of coefficients of a mathematical model postulated a priori, describing the property studied in function of variables of composition. This model is then used for forecasting purposes to determine simultaneously the copolymer composition and the ratio of different ingredients to obtain a mixture possessing the expected rheological properties. These mixtures were studied to elaborate a truly polyvalent cross-country ski-wax. Die Anwendung moderner Methoden fur den Aufbau optimaler Versuchsmatrices ist besonders geeignet, um die Eigenschaften von polymeren Gemischen zu prufen. Wir zeigen in dieser Arbeit, wie wir mit Hilfe einer begrenzten Zahl von gut ausgewahlten Versuchen die rheologischen Eigenschaften der Copolymeren von Laurylacrylat und Stearylmethacrylat im Gemisch mit einem Esterharz optimiert haben. Die Methodik ist auf die Koeffizientenbestimmung eines empirischen, von vornherein vorgegebenen mathematischen Modells gestutzt, das die gepruften Eigenschaften, gemas der verschiedenen Zusammensetzung, beschreibt. Dieses Modell wird benutzt, um gleichzeitig die Zusammensetzung der Copolymeren und die Anteile der verschiedenen Komponenten zu bestimmen, um Mischungen mit den gewunschten rheologischen Eigenschaften zu erhalten. Diese Gemische wurden gepruft, um ein vielseitiges Skiwachs fur den Skilanglauf auszuarbeiten.

A study has been made to determine the basic conditions to develop an economical manufacturing process for vinyl glycol ethers. To achieve the aforesaid purpose, the synthesis of the above-mentioned products by means of glycol ether dehydration has been experimentally investigated; the most suitable way to achieve it has been found to be an indirect dehydration (pyrolysis of the corresponding acetates). After having found the best way of synthetizing the vinyl glycol ethers, a determination has been made of the parameters which have a significant influence on the reaction carried out, in the gaseous phase, in a glass tubular reactor under normal pressure. An optimization study has enabled to develop a model from which the maximum response area has been found, selectivity being the objective function. Cette etude s'est proposee d'etablir les conditions fondamentales pour le developpement d'un processus economique pour la fabrication des ethers vinyliques de glycol. On a recherche la possibilite de les synthetiser par deshydratation des ethers de glycol. La voie, la plus convenable dans ce but a ete celle de la deshydratation indirecte (pyrolyse des acetates correspondants). Une fois defini la voie de synthese, on a determine les parametres ayant une influence significative sur la reaction qui a ete effectuee en phase gazeuse dans un reacteur tubulaire en verre sous pression normale. Une etude d'optimisation a permis d'obtenir un modele a partir duquel on a trouve la region de reponse — maximale, ayant comme fonction objective la selectivite.

We describe a method to optimize simultaneously Slater orbital exponents. The procedure is based on Newton's method and requires the derivatives of the energy as a function of the exponents. The calculation of these derivatives is described explicitly. The method has been applied to the hydrogen molecule.