Properties of high density polyethylene and its behaviour under ‘Galisol’ heat storage conditions

High density polyethylene (HDPE), crosslinked by electron beams in air, is presented as a latent heat storage material for energy storage applications at a temperature level of about 120°C. The study includes thermal investigations before and after the irradiation, investigations of the form stability, gel content determinations and microscopic investigations of HDPE. An electron energy of 0.4 MeV and a radiation dosage of 200 kGy were found to be the optimum conditions for the irradiation of the investigated HDPE in air. The pellets obtained were form-stable owing to the formation of a thin crosslinked surface layer (about 0.5 mm thickness). In spite of the presence of oxygen during irradiation, the melting enthalpy of the initial state was retained almost quantitatively. Apart from that, a quasicomplete irradiation of the pellets in volume in air, with a higher electron energy, is also possible. In this case about 95% of the initial melting enthalpy is obtained, providing a maximum gel content of 50%. Moreover, the paper offers a possibility of overcoming the low heat transfer power of HDPE by applying it in form of modified pellets in a ‘Galisol’ model storage unit with water as the heat transfer liquid. Owing to the large heat transfer area connected to boiling and condensation of water, excellent values of heat transfer power of 100–114 W/kg HDPE (ΔT=16 K) are obtained. These are comparable to those of salt hydrates, provided there is sufficient form stability. The significant influence of somewhat lower form stability on the heat output is shown.     

Etiology of alcoholism reconsidered: The case for a biopsychosocial process.

Argues that the etiology of alcoholism is best understood within the context of a longitudinal–developmental framework that includes physiological, behavioral, and sociocultural variables. It is further argued that G. E. Valliant and E. S. Milofsky's (see record 1982-30620-001) follow-up study on the etiology of alcoholism, although ostensibly set within such a framework, in fact understates the role of personality influences and dismisses childhood effects out of hand. Valliant and Milofsky's data are reviewed, and a different set of conclusions about the roles of childhood influences, personality, and cultural factors in the etiologic process is offered. An alternative integrative review of the existing longitudinal literature is presented that sets these findings in the context of a biopsychosocial process. (90 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Über die zweckmäßige Untersuchungsmethode der wiederholten mechanischen Beanspruchung unter korrosiven Bedingungen

A suitable method of investigating repeated mechanical loading under corrosive conditions For assessing the different parameters of repeated mechanical loading under corrosive conditions, Wöhler curves are unsuitable because of the large scatter. Such investigations must be carried out on numerous specimens and at stresses corresponding to the practical applications of the material. The results must then be statistically evaluated, the Weibull destribution being most suitable for the purpose. As a statistical evaluation based on the number of stress cycles endured before fatique failure does not yield a clear picture, it is worthwhile repeating the evaluation based on the period of time required to secure failure because, in this way, the influence of the test frequency becomes clearly apparent. Where the results of a fatigue test carried out in a corrosive medium are to be quited in literature, it is also necessary for clarity's sake, to state the test frequency.     

Mass Spectra of 4,4-Dimethyloxazoline Derivatives of Oxooctadecanoic Acids

The mass spectrometrical fragmentation patterns of the 4,4-dimethyloxazoline derivatives (DMOX) of the studied oxo fatty acids are easily to understand. The oxo group positions can be assigned unequivocally. The spectra are similar to those of the corresponding pyrrolidide derivatives. Since DMOX derivatization proofed to be good for the GC-MS analysis of epoxy fatty acids as well, the method could be interesting for studies on oxidized fatty acids, as well.     

Effect of high fat corn oil,olive oil and fish oil on phospholipid fatty acid composition in male F344 rats

Epidemiological and laboratory animal model studies have provided evidence that the effect of dietary fat on colon tumorigenesis depends on the amount of fat and its composition. Because of the importance of the composition of dietary fat and of tissue membrane fatty acid composition in tumor promotion, experiments were designed to investigate the relative effects of high fat diets rich in ω3, ω6 and ω9 fatty acids and colon carcinogen on the phospholipid fatty acid composition of liver, colon, small intestine, erythrocytes and blood plasma. At 6 wk of age, groups of animals were fed diets containing 5% corn oil (LFCO), 23.5% corn oil (HFCO), 23.5% olive oil (HFOO), and 20.5% fish oil plus 3% corn oil (HFFO). Two weeks later all the animals except the vehicle-treated animals received azoxymethanes.c. once weekly for 2 wk at a dose rate of 15 mg/kg body weight. Animals were sacrificed 5 d later and liver, colon, small intestine and erythrocytes and blood plasma were analyzed for phospholipid fatty acids. The results indicate that the phospholipid fatty acid composition of liver, colon and small intestine of HFCO diet fed animals, were not significantly different from those fed the LFCO diet. The levels of palmitoleic acid and linoleic acid were increased in erythrocytes and blood plasma of the animals fed the HFCO diet compared to those fed the LFCO diet. Feeding the HFCO diet significantly increased the oleic acid content and decreased the linoleic acid and arachidonic acid levels in various organs when compared to the HFCO diet. Animals fed the HFFO diet showed a marked increase in eicosapentaenoic acid and docosahexaenoic acid and a decrease in linoleic acid and arachidonic acid levels as compared to those fed the HFCO diet. The results also indicate that carcinogen treatment had only a minimal effect on the phospholipid fatty acid composition.     

The question of left hemisphere dysfunction in infantile autism.

Examines the hypothesis that dysfunction in the left hemisphere accounts for some of the primary behavioral and cognitive symptoms of autism. A particular variant of this theory is that language deficits, which are assumed to be attributable to left-hemisphere dysfunction, constitute the core deficit of the syndrome. The structure of these arguments and the empirical evidence are critically reviewed. It is concluded that the left-hemisphere hypothesis is inadequate to account for many of the cardinal features of autism, that it is based to some extent on flawed reasoning and weak evidence, and that it overestimates the importance of linguistic dysfunction in autistic children. Some of the questionable assumptions of this hypothesis include the following: (1) Language is always selectively impaired in autism; and (2) language reflects left hemisphere function. Nonlanguage evidence for left-hemisphere dysfunction is reviewed. Several alternative hypotheses are proposed to explain the possible link between left-hemisphere signs and infantile autism. (115 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence d’une erreur sur la covariance dans le problème de la détection d’un signal certain dans un bruit laplacien centré

Author considers the detection of a known, nonrandom signal in a nonstationary additive gaussian noise with continuous covariance. First she recalls results obtained when the covariance is known, she constructs the test which minimizes the probability of non detection β(α)for a given false alarm probability αand she computes β(α).Next she considers the case of an unknown but estimated covariance and then computes the false alarm probability and the probability of non detection in terms of the difference between the true covariance and its estimation.     

Die thermische Entwässerung hydroxydischer Eisenerze

Ermittlung der Abhängigkeit des Wasserdampfdrucks von der Temperatur in einer Vakuumapparatur. Thermogravimetrische Ermittlung des Gewichtsverlustes mit steigender Temperatur. Nachweis der Gitterumwandlung durch Elektronenbeugung.