Nonaqueous potentiometry of coal-derived asphaltenes and model nitrogen-containing compounds in acetophenone and nitrobenzene

A series of 34 nitrogen-containing compounds with a wide range of basicities was examined under differential nonaqueous potentiometric conditions in acetophenone and nitrobenzene. These compounds could be resolved into five classes based on pK_aand half-neutralization-potential (HNP) values. Asphaltenes isolated from the vacuum still overhead (VSO) and vacuum still bottoms (VSB) fractions of the H-coal process were titrated under similar conditions. The titration results of both asphaltenes indicated the presence of two classes of nitrogen-containing compounds, a titratable class of the pyridine-ring or aniline type and a nontitratable class.     

Structure in carbon/carbon fibre composites as studied by microscopy and etching with chromic acid

Structure of the matrix carbon in two industrially prepared carbon/carbon fibre composites and in four composites prepared in the laboratory was studied using optical microscopy and SEM examination of surface topography after oxidation in chromic acid solution. In the industrial composites and in the laboratory composites prepared with PAN fibres, the orientation of the basal planes of the matrix carbon is parallel to the fibre length within ～ 5μm of the fibre. The fibre-matrix interface is an area of weakness. Use of CVD coated carbon fibres, however, prevented this alignment; here the basal planes of the matrix carbon are randomly aligned relative to the surfaces of the fibres.     

One dimensional elasto-plastic wave interaction and boundary reflections

Elasto-plastic wave propagation in a one dimensional rod is treated by utilizing finite element analysis. The time dependence is handled by means of a variable time step numerical integration method. Elasto-plastic reflections from a fixed boundary and interaction of plastic waves are discussed.

Theoretical expressions are presented for determining the stress response for a material exhibiting bilinear hardening behavior during elasto-plastic wave interaction and boundary reflection. These expressions are employed to evaluate predictions made by the numerical procedure.

In the computations, steep wave fronts are approximated by ramps. The steepness of these ramps may be increased by refining the finite element grid. Excellent agreement is obtained between numerical and theoretical elastic and inelastic stress response levels.     

A restatement and test of Schlosberg's theory of emotion with two kinds of subjects from Greece.

Schlosberg's dimensional theory of emotion, including the dimension of tension-sleep, is tested to compare results obtained previously with American college students with those obtained in this study using Greek Ss. 15 Greek villagers and 15 college students in Athens comprised the 2 experimental groups which differed from each other in educational level and in lifetime movie attendance. The data indicate that Schlosberg's conclusions are now valid for non-Western groups as well as Western. Furthermore an emotion solid can be plotted from data collected by making use of Schlosberg's procedure, but the shape of the solid is not the same as that previously presented by Schlosberg. 18 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Volatile flavour components of malt extract

The Likens-Nickerson concurrent steam distillation-solvent extraction apparatus was used to obtain an essence from malt extract. The essence was submitted to combined gas chromatography-mass spectrometry (g.c.-m.s.), to examination by sulphurspecific and nitrogen-specific detectors, and to sensory evaluation of the components eluted from gas chromatographic capillary columns. Some 33 compounds were identified by direct examination by g.c.-m.s., another 14 by trapping and re-injection, which provides an efficient method of concentration, and a further six, which had not been previously identified due to interference from the solvent peak, by the use of charcoal adsorption traps. Results indicate that several compounds need to be combined to simulate malt flavour. The odour contributions of several components are discussed.     

An XPS study of binding energies of sulphur in carbon

X-ray photoelectron spectroscopy was used to measure binding energies of S 2p electrons of sulphur in S-trithiane, and in anisotropic carbon (heat-treatment temperature 873 K) formed from S-trithiane and from a humic acid derived from a Polish brown coal. A satisfactory technique is to prepare the specimens as a thin film on a gold plate. In all these materials, the sulphur atom environments are identical, corresponding to heterocyclic sulphur, 163.3 eV binding energy. Experimental binding energies are compared with those obtained using a charge-potential model from CNDO orbital calculations.     

A study of Hogan's model of counselor development and supervision.

The construct validity and developmental structure of R. A. Hogan's (see record 1966-00843-001) model of counselor development and supervision were studied using a sample of 141 counseling psychology graduate student trainees, interns, and professional staff in 20 university counseling centers. Counselor development questionnaire items were developed into 2 arrangements: one based on Hogan's concepts as he organized them into levels, and another derived empirically using factor analysis. The 2 configurations were compared for their ability to predict experience level of Ss using discriminant function analysis. Each empirical factor was also examined for relationship with experience by means of 1-way ANOVA with preplanned comparisons. Results indicate that counselor development is best described by a complex rather than a simple model and that it involves factors of Anxiety/Doubt, Independence, Method/Skills Training, Work Validation, Commitment Ambivalence, and Respectful Confrontation. Developmental profiles of these issues are described, and implications for supervision and training programs are discussed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A corrected modal representation of thickness vibrations in quartz plates and its influence on the transversely varying case

A modal representation of the thickness vibrations of rotated Y-cut quartz plates, which was used in the treatment of driven transversely varying thickness modes, is shown to be defective in certain respects. The differential equations and edge conditions for transversely varying thickness modes have been used in the accurate treatment of trapped energy resonators, monolithic crystal filters, and contoured quartz resonators, even though those defects were present. In this work those defects in the thickness solution are corrected along with the influence on the differential equations and edge conditions in the transversely varying case. The corrected modal representation shows that, because in practical applications to the above mentioned devices, the driving frequency is always near a thickness resonant frequency, essentially the same results will be obtained with the corrected representation as were obtained with the defective one, which explains why the results obtained with the defective equations were so accurate.