Microwave processing of electroceramic materials and devices

Microwave synthesis of nano-sized BaTiO₃ and decrystallized titania, and microwave sintering of electroceramics including BaTiO₃, Ba(Zn_1/3Ta_2/3)O₃ (BZT), lead zirconate–titanate (i.e. Pb(Zr _x Ti_1?x )O₃, or PZT), etc., as well as multilayer ceramic capacitors based on X7R, C0G, and ferrite multilayer chip inductors are presented. The results indicate that microwave processing significantly accelerated synthesis and sintering kinetics. As a result, processing time can be saved up to 90%, with the product properties comparable to or better than that of the conventional products.     

Affect and the overjustification effect.

Studied the role of affect as a mediator of the overjustification effect and proposed that negative affect has a critical detrimental influence on intrinsic motivation, either as a reaction derived from self-perception and evaluation processes or as a factor that acts independently of these cognitive activities. Two studies, with 180 undergraduates, used the typical overjustification paradigm to test these hypotheses. In Exp I, the overjustification effect was successfully replicated for both behavioral and self-report measures of intrinsic motivation. It is important that the negative affect paralleled these results and was greatest in those conditions in which intrinsic motivation was predicted and found to be low (e.g., expected reward). In Exp II, affect was directly manipulated, independently of the cognitive manipulations. Results show that the induced positive affect erased the decrease in intrinsic motivation that was observed in Exp I. It is suggested that what determines the decrease in intrinsic interest in any activity is, in part, the amount of negative affect that becomes associated with the activity. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fractographic study of high-density polyethylene pipe

High-density polyethylene (HDPE) pipe is now being used as an alternative to medium-density polyethylene (MDPE) for gas, water, sewage and waste-water distribution systems. Laboratory tests appear to show that HDPE is more able to suppress rapid crack propagation (RCP), whilst remaining sufficient resistance under the operational circumstances that lead to the type of slow crack growth observed in service failures. There have been many fractographic studies on MDPE pipe materials, actual pipe and fittings, but little on HDPE. A fractographic study of the type of HDPE pipe in current production has been undertaken. For these tests, whole pipe sections were subjected to either static or dynamic internal (water) pressurization fatigue loading. Failure mechanisms are discussed based on the fracture morphologies resulting from these tests. A further argument for good resistance of HDPE pipe to RCP is suggested. © 1998 Chapman & Hall     

Segregation analysis of breast cancer in a population-based sample of postmenopausal probands: The Iowa Women's Health Study

Inheritance of a major susceptibility gene for breast cancer has been primarily investigated in families with early-onset disease. However, familial clustering of late-onset breast cancer is well documented, and genetic factors may also be relevant. In the Iowa Women's Health Study, we evaluated evidence for a major gene after allowing for measured environmental risk factors. Two hundred sixty-five incident breast cancer probands were identified from a prospective cohort study of 41,837 women aged 55 to 69 years at baseline in 1986. A pedigree development form was mailed to the probands to ascertain all first-degree female relatives. A questionnaire and body measurement protocol were mailed to identified living relatives or surrogates. Segregation analyses were conducted on a total of 1,145 women in 251 families using regressive models as implemented in S.A.G.E. Mendelian codominant inheritance of an allele that produced an earlier-age-at-onset provided the best fit to the data. Incorporation of measured environmental risk factors as covariates yielded no significant improvements in the likelihoods. Approximately 50% of this population could be expected to carry a late-onset breast cancer susceptibility gene, and 23% of the population is susceptible because of the environment in which they live. Homozygous gene carriers are predicted to have a mean age-at-onset of 48 years, over 20 years earlier than heterozygotes; few cases would be expected among non-gene carriers. In conclusion, the transmission pattern of late-onset breast cancer may be determined by a common susceptibility gene.     

Antibiotics from the newly isolated Streptomyces elizabethii. II. Isolation and characterisation of the antibiotics

The principal antibiotics formed by Streptomyces elizabethii have been isolated and identified as actinomycins IV and V, together with a methylpentaene macrolide, elizabethin, stereoisomeric with previously reported compounds.     

Recruitment of minority group students and women.

Examined recruitment efforts of 65 fully approved American Psychological Association doctoral programs in clinical psychology. Results suggest that the programs were ambivalent about the recruitment of minority groups and of women in particular. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-consistently computed magnetization patterns in thin magnetic recording media

A model involving head motion is given for self-consistently computing magnetic recording medium magnetization patterns. The reduction in demagnetizing field due to the presence of the high-permeability head structure is included, as is record head removal, read head replacement, and computation of the readback voltage. The model is capable of handling an arbitrary record current waveform. Optimum record-current amplitude for nonreturn to zero (NRZ) digital recording is first determined, and then single-, double-, and quadruple-transition computations are performed using two different values of hysteresis loop squarenessM_{r}/M_{s}and both linear and exponential current reversals. Results are primarily for the Karlquist fringe field, but the recording properties of a head exhibiting regions in which the fringe field reverses sign are also briefly investigated.     

DIFFUSION COEFFICIENT OF OXYGEN IN LIQUIDS

The laminar dispersion of a solute in a capillary tube is used to measure diffusion coefficient of oxygen in liquids. A Polarographic type oxygen microelectrode is used to detect the pulse. Such a procedure overcomes the problems of measuring dissolved gases and makes it possible to apply this well known technique to oxygen-liquid systems. The results are in agreement with literature values     

Acute pretreatment with pyrazole and ethanol: effects on glucose-induced changes in insulin and glucagon

Ethanol suppressed, in a dose-related manner, glucose-induced insulin (IRI) release and thus delayed the disappearance of glucose from the blood of rats. Pretreatment with pyrazole, an alcohol dehydrogenase inhibitor, exacerbated the effect of ethanol on IRI release, glucose tolerance and glucagon (IRG) release. These results suggest that ethanol produces glucose intolerance by inhibiting glucose-induced IRI release and by augmenting IRG release. Moreover, these findings indicate that ethanol does not have to be metabolized completely in order to produce these effects.