MAGNETOSTRICTION EFFECTS IN CRACK LENGTH MEASUREMENTS

Abstract— Fatigue crack lengths were measured in a ferromagnetic material (a low alloy steel) using the d.c. potential drop technique. Significant cyclic fluctuations in potential were observed. Using discriminatory tests it has been established that the fluctuations may be attributed to inverse magnetostriction known as the Villari effect. The strain rate dependence of the fluctuations was investigated using sinusoidal, square and sawtooth waveforms, and the amplitude of the fluctuations was shown to be proportional to strain rate. In some cases the amplitude of the fluctuations was of similar magnitude to the crack length measurement potential.     

Stochastic control by measure transformation: A general existence result

Conditions for the existence of an optimal nonanticipative control policy are given for a general stochastic control model in which control is achieved by absolutely continuous change of measures.     

Variation in human thymidylate synthase is associated with resistance to 5-fluoro-2'-deoxyuridine

Two human colorectal tumor cell lines are differentially sensitive to growth inhibition by 5-fluorodeoxyuridine (FdUrd); cell line RCA is less sensitive to FdUrd than is cell line C. Thymidylate synthase (TS), a target of FdUrd, has been purified to homogeneity from both cell lines. Because of differences in the avidity for a folate ligand affinity matrix, TS forms from the cells were purified by two different procedures. Relative to the enzyme from C cells, the enzyme from RCA cells demonstrated higher Km values for the substrates deoxyuridylate and 5,10-methylene-tetrahydrofolate, a lower rate of association of the inhibitor 5-fluorodeoxyuridylate (FdUMP), a similar rate of FdUMP dissociation, and lower enhancement of covalent FdUMP binding by folate derivatives. The activities of the enzymes in situ and the catalytic efficiencies of the purified enzymes were similar. Thus, a cell line that is naturally resistant to FdUrd has been identified that expresses a TS with reduced affinity for FdUMP and 5,10-methylenetetrahydrofolate, relative to the enzyme expressed in a FdUrd-sensitive cell line.     

The data encryption standard in perspective

The Data Encryption Standard (DES) was approved as a Federal Information Processing Standard (FIPS) by the Secretary of Commerce on November 23, 1976. This Standard was developed as a part of the Computer Security Program within the Institute for Computer Sciences and Technology at the National Bureau of Standards (NBS). This paper places this standard in perspective with other computer security measures that can and should be applied to Federal computer systems either before or coincident to using the Data Encryption Standard. In 1972, NBS initiated the standards development effort leading to adoption of the DES. During this period, NBS solicited for algorithms and information upon which a standard could be based, published for comment the algorithm which best satisfied the requirements of an encryption standard, and coordinated the effort with both the potential using communities and supplying communities. This paper outlines the environment surrounding and the history of the Data Encryption Standard and discusses the objectives of additional standards to be developed within the computer security program.     

Optical scattering in a nematic liquid crystal induced by acoustic surface waves

A standing acoustic-wave pattern at 2.6 MHz is displayed in a nematic liquid-crystal film on a piezoelectric substrate. The striations are visible because the liquid crystal is optically anisotropic, because of the acoustically induced turbulence. This result has implications for liquid-crystal display systems.     

Temporal memory for performed activities: Intentionality and adult age differences.

Investigated rehearsal independency and the age insensitivity of temporal memory for prior performances on various tasks, using 36 young (aged 18.08–29.83 yrs) and 36 older (aged 60.25–85.83 yrs) adults. Ss performed under varying incidental/intentional memory conditions on 16 tasks (e.g., dot connection, card rotation, maze tracing) assigned to 4 time blocks separated by rest breaks. Following the last task, Ss received 2 tests of temporal memory. The first required identifying the time block in which each task was performed; the second required reconstructing the serial order in which the tasks had been performed. Temporal memory proficiency was equivalent under incidental and intentional memory conditions for each measure at each age level, thus supporting the rehearsal-independent nature of this form of episodic memory. However, an age deficit was present for each measure. Thus, temporal memory for performed activities appears to be age sensitive rather than age insensitive, as assumed by the automaticity of encoding hypothesis. However, the locus of age deficit in terms of the encoding stage or retrieval state of temporal memory remains undetermined. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality changes following transorbital lobotomy.

From the Rorschach findings presented, it can be inferred that "transorbital lobotomy results in a lessening of inner tension, a lessening of introspective self-awareness and insight, and a loss of ardent enthusiasm and active interest." A significant increase in W% is interpreted as some change in apperception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)