Physical axiomatics: Freudenthal vs. Bunge

The following remarks are intended to show that some of Freudenthal's recent criticisms of Bunge'sFoundations of Physics are wide of the mark. Freudenthal sets his criticisms of detail in a framework of some general considerations of the role played by axiomatic theories in the foundations of physics. In particular, he considers the notion of the objects of an axiomatic theory, the relation of an axiomatic theory to reality, and the notion of the transformation group of a theory. These topics are considered below.     

A fibre-optic thermometric sensor based on the thermo-optic effect of titanium dioxide coatings

An experimental determination of the thermo-optic effect of titanium dioxide is described in which the test element is a thin film deposited onto the end face of an optical fibre. The film acts as an etalon. The reflectivity of titanium dioxide films was measured as a function of temperature experimentally over the range 20 °C to 500 °C, and modelled theoretically to yield a value of the thermo-optic coefficient of − 1.49 × 10⁻⁴ K⁻¹. The use of the data in the design of a thin-film optical fibre temperature sensor is described.     

The effect of proximity of the landing gear lights on its turbulent wake

A simplified model of a landing gear is tested in a wind tunnel to investigate the effect of the landing light location on the resulting noise generation. Examination of the near-field pressure fluctuations, combined with phase-locked stereoscopic particle imaging velocimetry of the unsteady wake identified two distinct sources of pressure fluctuations. The higher frequency source has a wide frequency band and is situated in the outer regions of the wake near the lights. On the other hand, the lower frequency source is found to be stronger, has a narrower frequency band and is developed further downstream in the wake, closer to the wake centreline. The lower frequency source is observed to be rather robust as it is hardly affected by the location of the landing lights, whereas the higher frequency source becomes weaker as the spacing between the lights is reduced. The effect of a splitter plate positioned downstream of the landing gear strut is also investigated as a means of reducing the lower frequency pressure fluctuations. Although the lower frequency source is considerably weakened by the splitter plate, substantial enhancement of the higher frequency source is observed.     

Synthesis of 1-Aryl-3-phenethylamino-1-propanone hydrochlorides as possible potent cytotoxic agents

1-Aryl-3-phenethylamino-1-propanone hydrochlorides 1-10, which are potentialpotent cytotoxic agents, were synthesized via Mannich reactions using paraformaldehyde,phenethylamine hydrochloride as the amine component and acetophenone, 4'-methyl-, 4'-methoxy-, 4'-chloro-, 4'-fluoro-, 4'-bromo-, 2',4'-dichloro-, 4'-nitro-, 4'-hydroxyacetophenone or 2-acetylthiophene as the ketone component. Yields were in the87-98 % range. Of the compounds synthesized, compounds 2, 6-8 and 10 were new. Theoptimum reaction conditions were investigated by changing the mol ratios of the reactants,the solvents and the acidity levels using 1 and 10 as representative targets. It was observedthat the best mol ratio of the ketone, paraformaldehyde and phenethylamine hydrochloridewas 1:1.2:1 (compared with a 2:2.1 ratio), and the most suitable reaction medium wasethanol containing concentrated hydrochloric acid (compared with only ethanol or nosolvent). This study may serve as a guide for the conditions of the reactions to synthesizecompounds having similar chemical structures.     

Longitudinal endolymph movements and endocochlear potential changes induced by stimulation at infrasonic frequencies.

The inner ear is continually exposed to pressure fluctuations in the infrasonic frequency range (< 20 Hz) from external and internal body sources. The cochlea is generally regarded to be insensitive to such stimulation. The effects of stimulation at infrasonic frequencies (0.1 to 10 Hz) on endocochlear potential (EP) and endolymph movements in the guinea pig cochlea were studied. Stimuli were applied directly to the perilymph of scala tympani or scala vestibuli of the cochlea via a fluid-filled pipette. Stimuli, especially those near 1 Hz, elicited large EP changes which under some conditions exceeded 20 mV in amplitude and were equivalent to a cochlear microphonic (CM) response. Accompanying the electrical responses was a cyclical, longitudinal displacement of the endolymph. The amplitude and phase of the CM varied according to which perilymphatic scala the stimuli were applied to and whether a perforation was made in the opposing perilymphatic scala. Spontaneously occurring middle ear muscle contractions were also found to induce EP deflections and longitudinal endolymph movements comparable to those generated by perilymphatic injections. These findings suggest that cochlear fluid movements induced by pressure fluctuations at infrasonic frequencies could play a role in fluid homeostasis in the normal state and in fluid disturbances in pathological states.     

Gödel-type spacetimes in f(R)-gravity

We focus on one of the famous problems in theoretical physics today: the problem of energy-momentum localization. Although many authors have endeavoured to solve this problem, it has remained unsolved until now. In this work, we consider the generalized version of the Landau-Lifshitz definition in f(R)-Gravity to discuss the energy-momentum localization problem in Gödel-type metrics. We also take into account five popular f(R) models to obtain specific results.     

MgSo4—C2H5OH—H2O三元系汽—液—固平衡的研究

H测定过MgSO_4-C_2H_5OH-H_2三元系在25℃、50℃、75℃的液固平衡和部分不饱和溶液汽液平衡的总压和分压。本文补充了30℃、0℃和-5℃时的溶解度数据,得到分层温度和浓度范围,绘出了溶解度图。测定了25℃和30℃饱和溶液的密度,粘度和平衡总压力。根据Jaques“假二元系”理论用Wilson、Uniquac和NRTL活度方程计算了溶     

Correlative Cellular Mass Spectrometry Imaging and Amperometry Show Dose Dependent Changes in Lipid Composition and Exocytosis

Aberrant functioning of the proteasome has been associated with crucial pathologic conditions including neurodegeneration. Yet, the complex underlying causes at the cellular level remain unclear and there are conflicting reports of neuroprotective to neurodegenerative effects of proteasomal inhibitors such as lactacystin that are utilised as models for neurodegenerative diseases. The conflicting results may be associated with different dose regimes of lactacystin and hence we have performed a dose dependent study of the effects of lactacystin to identify concurrent changes in the cell membrane lipid profile and the dynamics of exocytosis using a combination of surface sensitive mass spectrometry and single cell amperometry. Significant changes of negatively charged lipids were associated with different lactacystin doses that showed a weak correlation with exocytosis while changes in PE and PE−O lipids showed dose dependent changes correlated with initial pore formation and total release of vesicle content respectively.