The physics of mechanical alloying: A first report

In this paper, we present a first attempt to define the basic geometry, mechanics, and physics of the process of mechanical alloying. The geometry of the collision events which lead to particle fragmentation and coalescence is modeled on the basis of Hertzian contacts between the grinding media which entrap a certain amount of material volume between the impacting surfaces. This geometry essentially defines the volume of material affected per collision, and from this information and characteristics of the specific mill and the material being processed, impact times, powder strain rates and strains, powder temperature increase, powder cooling times, and milling times can be approximated.     

Repeated point contact loading on Ce-TZP

The deformation and fragmentation behaviour in a toughened ceria-stabilized zirconia ceramic have been investigated by using unlubricated repeated metallic point contact loading at room temperature to explore the possibilities of cyclic fatigue effects. All tests were conducted on a purpose-designed and built computer-controlled apparatus. 120° hardened silver steel cones were cyclically loaded on the polished Ce-TZP substrate, and the damage was observed and analysed as a function of the number of cycles for loads of 19.6 ± 9.8 N. The ground tips of the cones plastically deformed during the initial loading cycle to produce a flattened end which conformed with the substrate. A tetragonal → monoclinic martensitic transformation occurred in the zirconia beneath, and adjacent to, the contact zone. This transformation zone increased in size as the number of cycles increased, even though there was virtually no change in the diameter of the flattened tip. The expansion associated with this phase change in the zirconia caused granular lifting from the surface, at the edge of the contact zone, that resulted in intergranular fragmentation and spelling of the substrate. The hardness of the substrate in the contact zone increased by approximately 15% after 2×10⁵ cycles. Traces of metal transfer onto the ceramic substrate could be observed only at 2×10⁵ cycles and above.     

Formal computations of non deterministic recursive program schemes

We extend to non deterministic recursive program schemes the methods and results which permit definition of the semantics of such schemes in the deterministic case. Under natural hypothesis the set of finite and infinite trees generated by a scheme is proved to be the greatest fixed point of the functional mapping usually attached to this scheme.     

In-pile creep study on mixed oxide (U,Pu)O2

The in-pile creep of a mixed oxide UO₂-PuO₂ under compression was studied up to fission rate of $\text{6 × 10}{}^{13}\text{f cm}{}^{\mathrm{?3}}\text{s}{}^{\mathrm{?1}}$, for stresses up to 26.5 MN m^?2, at temperatures ranging from 700 to 900°C. The results obtained agree with those of other authors. The creep rate is proportional to the applied stress and to the fission yield. However, it is athermal within the temperature range explored and is not affected by the burn-up, which has so far reached 30000 MWd t^?1 (3.6% FIMA). When the sample is under compression the fuel swells under the action of the fission products formed in the oxide during its irradiation. The swelling rate is about that commonly accepted for a clad fuel element. Finally it seems that the oxide swells more when free from stress than when subjected to a stress field, but this point has to be confirmed.     

Algorithmes relatifs a la decomposition des polynomes

Améliorations et remarques sur un algorithme dû à H. Zassenhaus, qui fournit la factorisation d'un polynôme à coeffecients entiers. Puis un algorithme très rapide et très simple qui donne des informations utiles sur la décomposition d'un polynôme modulo p. Applications: tests modulo p d'irréductibilité, de décomposition en facteurs linéaires d'un polynôme, de décomposition d'un idéal en O (log p) opérations.     

Epitope mapping of the major inner capsid protein of group A rotavirus using peptide synthesis

Nucleic acid amplification by polymerase chain reaction (PCR) is a very powerful technique in terms of sensitivity but is limited in terms of ability to perform accurate quantitation. While there is a theoretical correlation between copies of input target sequence and those of PCR product, the quantitative nature of this relationship is obscured by unpredictable variations in reaction conditions and by inhibitory and/or stimulatory substances which might be present in sample preparations, especially those derived from biological fluids. To reliably estimate copies of input DNA target from PCR product, we designed a combination of internal and external control systems coupled to DNA/RNA hybridization and enzymatic immunodetection techniques. The internal control system served to monitor amplification efficiency and to correct for the effects of inhibitors or stimuli on the efficiency of the DNA amplification. The assay is quantitative, nonisotopic, and can be widely applied to assessment of the quantity of DNA present in a wide range of preparations.     

Prospective and cross-sectional mood reports offer no evidence of a "blue Monday" phenomenon.

Conducted 3 studies, 2 using prospective and 1 using cross-sectional methods, to examine mood variation in married men over the days of the week. In Study 1, 46 Ss (mean age 42 yrs) kept a record of daily events, illnesses, and moods for 90 consecutive days. In Study 2, 58 Ss (mean age 43 yrs) also kept records, but for 112 days; severe dysphoric mood was also measured. 57 Ss in Study 2 also were asked on the telephone about which days of the week were worst and best for their mood. 21 Ss from this study also participated in a study in which they reported on their mood 5 times/day for 2 wks. In Study 3, 616 Ss (aged 18–60 yrs) completed 1 depressed mood scale. Although Ss thought that their mood was lowest on Monday, mood measures collected on a daily basis did not support the belief. Monday's mood was not different than mood on Tuesday, Wednesday, or Thursday, but positive mood was higher and negative mood was lower on the weekend; measures of depressed mood did not vary by day of the week. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The funding of psychological health care services.

Examines issues related to the funding of psychological services identified by a joint task force of the Canadian Psychological Association and the Council of Provincial Associations of Psychologists. Discussion focuses on the identification and assessment of systems, sources, and methods of payment. The review of delivery and payment systems suggests that the majority of psychologists use a few payment sources and methods and that education about payment alternatives is needed. Implementation of training in psychology practice innovations and implications of the task force findings for professional standards are discussed. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One determinant of the capacity to free-associate in psychotherapy.

The hypothesis tested was that "clients whose behavior when asked to free associate is highly variable, flexible, or productive exhibit significantly greater variability when judging the extent of autokinetic movement on successive trials than Ss whose behavior at the outset of psychotherapy is highly inflexible, stereotyped, or rigid." 7 neurotic college student analysands in the extremely flexible group were matched with 10 Ss of the extremely rigid group for relevant personal variables. Sherif's autokinetic apparatus was used, and each S's judgmental variability was determined. The highly significant difference between autokinetic variability scores of the 2 groups lends strong support to the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)