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Abstract  

Thin films of 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexane carboxylate were UV irradiated (1.1 J cm-2) under isothermal conditions ranging from 0 to 50C. Under these conditions the polymerization advanced quickly but only to a conversion level of less than 10% before the reaction rate slowed by more than an order of magnitude. This drop off in rate was not caused by the glass transition temperature, T g, reaching or exceeding the reaction temperature, T rxn, since the epoxide's T g remained at least 40C below T rxn. Raising the sample temperature above 60C caused a sharp increase in the conversion level. At 100C conversion exceeds 80% and the ultimate T g approaches 190C. The addition of 10 mass% 1,6-hexanediol, HD, to the epoxy caused the conversion at room temperature to quintuple over the level obtained without the alcohol present. The heat liberated from this alcohol epoxy blend during cure on a UV conveyor belt system caused the sample's temperature to increase by about 100C above ambient whereas the epoxy alone under these conditions only experienced a modest temperature rise of about 26C. If the amount of HD in the blend is increased above 10% the heat of reaction at 23C decreases due to HD being trapped in a nonreactive crystalline phase. Boosting reaction temperatures above 50C melts the HD crystals and yields significantly improved conversion ratios. As the level of alcohol blended with the epoxy is raised its ultimate T g is lowered and when the concentration of alcohol in the blend nears 30 mass%T g drops below room temperature.

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Some interpolation and smoothing techniques have been analyzed for velocity and acceleration determination from kinematic LEO (Low-Earth Orbiter) orbits. Tests were performed on a simulated GOCE orbit and on a kinematic CHAMP orbit as well.

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The shake map methodology for seismic hazard studies has been applied to a sector of Bucharest, the capital of Romania.  Geological and geotechnical profiles are known for this region. We have chosen as seismic input the event of  30 August 1986, M W = 7.1.  We discuss the propagation of a synthetic signal with known source characteristics, from source to bedrock and back to surface. It is possible to produce surface synthetic signals in the studied area, having very similar characteristics (accelerations) to the observed ones.

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features of citations of publication output of Polish scientists in terms of their citability from the concept of citation acceleration a = L / t 2 = π( R / t ) 2 ( t is publication duration of a scientist), and (4) to discuss the influence of

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Abstract

The beneficial effects of hippotherapy lie in the transmission of the horse's movements to the patient. The aim of our work was to create a measurement method for objective evaluation that can be used in natural settings without interfering with therapy.

Methodology/Principal findings

Our measurement system consists of three treble axis accelerometers connected to a data logger. Software was developed for data analysis and post processing. A commercial DVD recording camera was used to document the hippotherapy session. In this paper we present the results obtained in pilot measurements on ten children with cerebral palsy. For reference, a skilled rider was measured on the same horse using a passive following seat.

Conclusions

The acceleration diagrams show common characteristics useful to the interpretation of the movement transfer during hippotherapy as well as individual patterns indicating alterations in the movement reactions of different patients.

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Abstract  

With reference to social constructivist approaches on citing behavior in the sciences, the hypothesis of acceleration of citing behavior after the millennium was empirically tested for a stratified random sample of exemplary psychology journal articles. The sample consists of 45 English and 45 German articles published in the years 1985 versus 1995 versus 2005 in high impact journals on developmental psychology, psychological diagnosis and assessment, and social psychology. Content analyses of the reference lists refer to the total number of references cited in the articles and the publication years of all references. In addition, the number of self-references, the number of pages, and the number of authors were determined for each article. Results show that there is no acceleration of citing behavior; rather, on the contrary, a significant trend is revealed for an increase in authors’ citing somewhat older references in the newer journal articles. Significant main effects point also at more citations of somewhat older references in the English (vs. German) journal articles as well as in articles on social psychology and psychological diagnosis (vs. on developmental psychology). Complementary analyses show that multiple authorships and the number of pages as well as the total number of references and the number of self-references increase significantly with time. However, percentage of self-references remains quite stable at about 10%. Some methodological and statistical traps in bibliometric testing the starting hypothesis are considered. Thus, the talk that has been circulating among psychology colleagues and students on the potential millennium effects on citing behavior in the sciences (which can, however, become a self-fulfilling prophecy) are not confirmed—at least for psychology journals.

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We have obtained empirical laws for the variation of the Earth parameters with geologic time that are in agreement with coral fossil data obtained by Wells and Runcorn. Our model predicts that the day is lengthening at a rate of 2 ms/century at the present time. The length of the day when the Earth was formed is found to be 6 hours and the synodic month 56 days. The angular momentum of the Earth-Moon system is found to be increasing with time. The origin of the presently observed acceleration of the Moon is explained. The model predicts that the Moon is accelerating at 20.6 arc sec/cy2 at the present time.

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Karst regions are very vulnerable with respect to natural and human-activity related hazards. Some of them with beautiful caves were proposed to be of national value. The examination of broken and slim intact speleothems in Bulgarian caves (Varteshkata and Elata caves, western part of Balkan Mountain Range, North-West Bulgaria) allows estimating an upper limit for horizontal peak ground acceleration (PGA) generated by paleo-earthquakes.The density, the Young’s modulus and the tensile failure stress of the samples originating from broken speleothems have been measured in a laboratory.The fundamental frequency and damping of speleothems have been measured in cavity by in situ observations.The value of the upper limit horizontal ground acceleration resulting in failure and the natural frequency of speleothems were assessed by theoretical calculations using mechanical parameters — the density, the Young’s modulus and the tensile failure stress — of the samples originating from a broken speleothem from Elata cave.The ages of the samples taken from the investigated stalagmites have been determined by alpha spectrometry.The pure elastic behaviour in analytical modeling and calculations have been used.According to our modeling results the investigated speleothem has not been excited by a horizontal acceleration higher than 0.144 g in case of Varteshkata cave, and 0.326 g in case of Elata cave during the last few thousand years. These results can serve to improve the present seismic risk policy for karst regions, too.

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Abstract  

The article makes a bridge between quartz crystal microbalance (QCM) and conventional beam balances revealing the role of the field in mass measurements. Thus, three fundamental principles for mass measurements are formulated and demonstrated: the field principle, the mass sensitivity principle and the general equivalence principle.

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Recently, significant efforts were attempted to the re-organization of the former network established in the early 80’s. As a result, sixteen digital accelerograph stations were installed most of them concentrated in seismic active, densely populated and industrialized areas. In fact, analog SMA-1 recorders were replaced by digital QDR-s upgrading thus network’s effectiveness. A number of accelerograms from small magnitude events have been recorded and data were properly processed in order to obtain the maximum ground motion parameters. Particular importance was devoted to the “band-pass” filter parameters in order to eliminate the noise that influences the spectral characteristics of the signal as well as the absolute values of maximum ground motion parameters in case of strong earthquakes.

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