Short Time Range Research Articles

SEISMIC ACTIVITIES AND CRUSTAL MOVEMENTS AT THE YAMASAKI FAULT AND SURROUNDING REGIONS IN THE SOUTHWEST JAPAN

Data from the continuous observation of microearthquakes which occur along the Yamasaki Fault and in the surrounding regions have been analyzed. There are some active lines of alignment of microearthquakes. Each of these corresponds to an active fault. We can find some properties of the block structure and the block movements of the crust from the temporal variation of the activity. The fractured zone of the Yamasaki Fault shows some characteristic behaviors of strain change related to the activity of microearthquakes. These phenomena are closely related to the change of water level of the river along the fault and rainfalls at the concerned region. Heavy rainfalls often triggers the occurrence of shallow earthquakes along the faults. Such characteristics are very useful for the earthquake prediction in very short time range.

アカマツ苗条の力学的性質に関する研究

In this study, we investigated some mechanical properties during growth of Japanese red pine (Pinus densiflora Sieb. et Zucc.) seedlings in air-dry.The results obtained are summarized as follows.(1) The values of tensile strength for pine seedlings having different growing duration varied depending upon the growing duration, and the variation could be divided into two steps on the basis of the degree of growth of pine seedlings; in the early step, pine seedlings contained only primary xylem, and, in the late step, pine seedlings contained secondary xylem.(2) The fracture surface by tension test differed depending upon the degree of growth for seedlings; at the early stage of growth, the fracture surface showed a simple fracture type at the cell wall in primary xylem, separation of intercellular layer, deformation in cell shape and etc., and, at the late stage of growth, the fracture surface showed a complex fracture type at each layer of cell wall in secondary xylem but did not show any clear deformation of cell shape and separation of intercellular layer.(3) Tensile relaxation tests were carried out on three pine seedlings having different growing duration. The difference in relaxation spectra among three seedlings could be shown by the position of maximum in the short-time range, and the position of the maximum seemed to be related to the growing of xylem tissue within seedlings.

積層ＧＲＰ板の圧縮特性

This paper is concerned with the time- and temperature dependences on the compressive properties of the plain fabric glass cloth reinforced laminates (GRP) and on the tensile properties of the epoxy resins used as the matrices of the GRP.The results obtained are summarized as follows:(1) The master curves of the relaxation moduli for the epoxy resins and the creep compliances for the GRP can be constructed, using their thermo-rheological simple properties. As for the time- and temperature shift factors, they are in good agreement each other quantitatively.(2) It was found that the relation between the relaxation moduli of the matrix and the creep compliances of the GRP at low temperatures in the short time range can be uniquely determined by the rule of mixture for viscoelastic materials, independent of the conditions of their circumstance such as time and temperature.(3) The above-mentioned results (1) and (2) are similar to those obtained in the previous paper concerning with the flexural properties of the unsaturated polyester resins and GRP containing these resins. Therefore, these results seem to hold generally in the stress-strain relations of various GRP under any load conditions.(4) The time-temperature shift factors of the epoxy resin and the unsaturated polyester resin can be approximately expressed by the two Arrhenius equations having different activation energies. The boundary temperatures of the two equations are nearly equal to the glass transition temperatures of the resins.

Solvent effect on ν 8 band shape of dichloromethane

The infrared absorption band shape of the ν 8 mode of dichloromethane has been measured carefully in twelve kinds of solvent. The rotational correlation functions have been calculated by the Fourier transformation of the observed band shapes, and the solvent effect on those functions has been discussed. The correlation functions show non-exponential decays in a short time range for any solutions, and this indicates that the molecular motions do not obey a simple rotational diffusion model. On the other hand, the correlation functions in a longer time region show clear-cut exponential decays for various solutions, and the relaxation times in the exponential decays have been evaluated. Quite a linear relationship has been observed between the relaxation times and the viscosities of the solvents used, and the effect of the solvent viscosity on the rotational motion of the solute molecule hea been investigated.

21/4Cr-1Mo鋼のクリープ破断強度に及ぼす熱処理の影響

The creep rupture strength of a 21/4Cr-1Mo steel was studied in relation to preheat treatment and microstructure. Results were summarized as follows:(1) Creep rupture strength did not always proportional to the strength at room temperature. In the short time range, the creep strength was decreased in the order of the OQ (15mm ∅; bar was quenched into still still oil), the WQ (15 mm ∅; bar was quenched into stirring water), and the FC (furnace cool in 30°C/hr) steel, while in the long time range the order was the FC, the OQ, and the WQ steel.(2) The greatest creep strength of the OQ steel, in the short time range, was attributable to the following two points;(i) it contained much more finely dispersed carbides than the FC steel, and (ii) the ratio of needle-like carbides to total number of carbides was higher and the ferrite grains were more stable than in the WQ steel.(3) The superior creep resistance of the FC steel could be due to the stability of the ferrite grains and the sluggish precipitation of M2C carbides during creep.(4) The creep stress influenced on the formation of rod-like carbide, the acceleration of softening in quenched steels and the acceleration of spheroidization of pearlite.From these results, it was concluded that carbides, e3pecially the mode of precipitation of carbides during creep test, played an important role in the creep strength, and the shape of ferrite grains was also important to ensure the microstructural stability at high temperatures, though this effect was in a less degree.

Photocount Statistics of Transient Laser Light

The transient phase-independent solutions of the laser Fokker-Planck equation are analyzed for a short range of time following the moment of the switching on of the oscillations. The evolution of the laser light in time is then represented as a nonstationary Gaussian random process. On the basis of this fact, the factorial moment generating function of the photocount probability distribution is derived, which accounts automatically for all the finite-counting-time corrections. The time development of the first two moments is compared with the recent results of Arecchi and Degiorgio.

Molecular Motion as Seen by Neutron Scattering

AbstractThe neutron scattering technique is particularly useful to study the short time and short range phenomena appearing in non‐equilibrium statistical mechanics. The linear velocity‐auto‐correlation function and the rotational relaxation functions are both accessible by the neutron technique. In the present review article examples are given on both these aspects of neutron scattering results. It is mentioned that an understanding of the scattering results on simple monatomic liquids like argon and sodium requires that collective effects are included. Regarding the rotational behavior the general formalism developed by Sears is used to understand results on methane. It is pointed out that no really good agreement between theory and observation is obtained within the present theoretical framework based upon the assumption of decoupling of rotational and translational motion. A two‐component model is described which involves the assumption of existance of both librational and (damped) rotational components in the rotational behavior. Using this model the neutron results display the transient nature of the liquid phase.

耐候性鋼の点溶接におけるテンパ条件選定に関する研究

This report gives details of a new method to determine post heat (tempering) conditions for the spot welds in anti-corrosive high tensile steel sheets.Up to the present, selection of post heat conditions is normally based on the temperature measurement of the nugget. Since this can not be expected to give accurate indication of optimum conditions, the ductility of the weld must be checked by cruciform tension strength, micro-examination and hardness. In practical application a slight variation in welding and post heat conditions can have a singificant effect on weld ductility. Thus, as it is difficult to check the post heat effect by such a method the conditions selected are to be impracticable.The principle of the new method developed in this report is as follows : Electrical resistance of steels rises with temperature but the rate of its rise drops remarkably because of austenite transformation. When the weld periphery has been properly tempered, the center is heated above the level of austenitising temperature. Consequently, the resultant resistance in the weld during post heating increases first and then decreases slowly or steeply depending on post heat current level. Thus, by analysing the resistance characteristics, the optimum post heat conditions can be selected. Practically, since the resistance corresponds to voltage drops, post heat conditions to give the required heat treatment can be readily obtained from the records on an oscilloscope. Short post heat time and narrow allowable range of post heat time will be obtained for higher current while long post heat time and wide allowable range will be for small current.To check the validity of this method, fatigue strength test and hardness survey were carried out; the results are in fairly good agreement with post heat conditions selected.Plotted on the log-log scale, the post heat variable comes out in a straight line. This relation can be formulated by empirical equations.The determination of proper quench time was the most time-consuming operation but it can be made simply by analysing the voltage drop records.The rate of rise in electrical resistivity with temperature is measured and the average temperature in the weld during post heating is calculated.

Long-time study of Poisson's ratio for polyethylene stressed in the small strains range

The time dependence of the Poisson's ratio μ for low-pressure polyethylene has been studied by a method involving superposition of time and temperature (in the short-time range) and by recording creep curves for the longitudinal and transverse strains (under prolonged loading). It is shown that μ is not constant, its value changing from approx. 1/3 for short loading times to approx. 1/2 under prolonged loading conditions.

INTERSTITIAL TIME-DOSE CORRECTIONS.

The application of “Strandqvist-type” curves or tables to the adjustment of time and dose factors of external beam treatment has become standard practice in clinical radiation therapy. Most such adjustments, however, are based on reported observations involving time periods of weeks. Isoeffect doses in the shorter time range have been obtained by extrapolation and cannot be used with validity. Paterson (1), in reviewing clinical time-dose considerations, described an isoeffect curve for interstitial radium gleaned from clinical observations of “Manchester system” radium needle implants. Since few treatment centers have the opportunity to observe comparable numbers of cases, it is appropriate to present this information in a clinically useful form. The upper curve (Fig. 1) is a rearrangement of Paterson's curve on a “Strandqvist-type” log-log plot for comparison with other clinical time-dose information. Since in interstitial work, the dose rate is often fixed by the implantation prior to a final dose decision, the same information is plotted herein to facilitate selection of isoeffect times for various dose rates. “Manchester System” standard dose-rate, dose, and time are indicated by dotted lines for convenient reference. It is noted that the data from which Paterson's curve was drawn are not reported in detail. It may be assumed that the greatest numbers of cases and maximum validity of the curve cluster about the reference “standard dose.” Clinical approximations taken at distances from the reference standard are correspondingly less meaningful.

Creep Rupture Strength of the Specimens from Actual Turbine Rotor Shaft

Creep rupture test were conducted at 538°C (1000°F), 565°C (1050°F) and 593°C (1100°F) on the 1Cr-11/4 Mo-1/4V steel which is used as the high- and medium-pressure turbine rotor shaft up to 1100mm diameter.Specimens were taken out of inner and outer part of an actual rotor, having radial, tengential and longitudinal direction, respectively.Test results are summarized as follows:(1) The longitudinal specimen has about 10% higher creep rupture strength than radial specimen which has higher strength than tangential specimen also by about 10% in terms of 1000 to 10000 hour creep rupture stress at each temperature.(2) Specimens from outer part of rotor show lower rupture strength than specimens from inner part. Though both inner and outer part have the bainite microscopic structure, the inner part has the upper bainite structure and the outer part has the lower bainite structure, since the cooling rate at quenching is slower in the inner part.The present result which shows that the upper bainite has better creep rupture strength than the lower bainite is in conformity with the previous results on small specimens.(3) The creep rupture stress of the notched specimen is higher than that of the smooth specimen in a short time range of testing and lower in a long time range.This intersecting of the rupture stress vs. time-curve for the notched and the curve for the smooth occurs at a shorter time of testing and when the testing temperature is made higher.(4) Comparing with the results of the tests by Werner et al.2), Conrad et al.4) and Rankin et al.5) on the 1 Cr-11/4 Mo-1/4V steel turbine rotor shaft, the present result shows nearly similar creep rupture strength to their results, and speaking at some length, the present data show a little lower strength in short time range and a little higher strength in long time range than theirs.(5) Elongation at creep rupture in the present test is similar to or a little higher than Rankin's.The specimen from inner part of a rotor gives longer rupture time but shorter elongation at rupture than the specimen from outer part.

Fast Response Pulse Tests Use Gamma Milking

The usefulness of radiotracers for flow studies is extended into the shorter time range. Thus the residual contamination problem associated with long life isotopes is minimized. The separation of gamma-emitting barium-137 from its parent cesium-137 by resin exchange permits the frequent separation and injection of a sharp pulse of the short half life (2.6 minutes) Ba/sup 137/ using an automatic device known as the gamma milker. The penetrating gamma rays of the tracer are measured by scintillation detectors mounted on the external surface of the process vessel thus eliminating the need of removing samples for subsequent analyses. High speed recording equipment permits the measurement of pulse responses ranging from a few tenths to 100 seconds.

The Relation between Water Temperature and Morphology in Dendraster

An empirical correlation between mean water temperature and test weight in shallow-wrater forms of the living echinoid Dendraster excentricus (Eschscholtz) shows that sand dollars of a given size are heavier in cold water than in warm water. The correlation is interpreted as the result of phenotypic (non-heritable) adaptation to water temperature. Changes in test weight are accompanied by changes in several morphological characters that have been used to classify members of the genus Dendraster into species and subspecies. Investigation of the value of these characters as indicators of paleotemperatures in the fossil record of Dendraster indicates that the characters have evolved over time, thus eliminating their use as indicators of absolute temperatures. Furthermore, genetic or evolutionary differences in the same characters are recognized between certain geographically separated contemporaneous populations in the Pliocene. Thus only within a small geographic area and within a short range of time can morphology be used to deduce relative differences in temperature.

Studies of the Vulcanization of High Elastic Polymers. II. Vulcanization of Natural Rubber with Thiuram Disulfides. Part 2

Abstract This paper gives some insight into the kinetics of thiuram vulcanization. The following results were obtained. 1. The decrease of concentration of thiuram disulfides during vulcanization is a first-order reaction in the range of short vulcanization times. At longer reaction times, departures occur. The process then takes place more slowly. 2. The departures from the course of a first-order reaction are displaced with decreasing temperature toward the range of longer vulcanization times. 3. At 87° C, the reaction of tetramethylthiuram disulfide is of the first order over the whole range of vulcanization temperatures chosen, and at this temperature no deviations whatever are observed. 4. The same relationships are found in the kinetic study of dithiocarbamate formation. 5. From the combined results, it is concluded that, besides the two reactions occurring independently of each other during vulcanization, the diffusion of the reaction partners also has some influence on the kinetics. 6. The limiting value of dithiocarbamate formation is correlated with the macromolecular structure of the polyisoprene, and it is shown to be probable that this limit is not determined fundamentally by the chemistry of the vulcanization reaction.

The Efficacy of the Intracutaneous Route of Injection and the Susceptibility of the Hartley Strain of Guinea Pigs in Experimental Allergic Encephalitis

Abstract Sterile disseminated encephalitis was produced by Rivers and his associates in monkeys by injecting CNS tissue using often repeated injections (1). By means of adjuvants consisting of paraffin oil and killed mycobacteria or Nocardia asteroides, rapid production of encephalomyelitis has become possible. This has been demonstrated in monkeys, guinea pigs, mice, rabbits and dogs (2–7). The substance responsible for the induction of allergic encephalitis has been the subject of extensive investigations (8). In such studies, it is essential to find conditions which afford the production of encephalitis by a single injection and in a relatively short and narrow range of time. It is also advantageous to produce easily recognizable clinical symptoms which can be correlated readily with histological findings. It is desirable that a large percentage of the injected animals should respond. In many of the studies on the fractions from the central nervous tissue, repeated injections have been used.

Constant stress elongation of soft polymers: Time and temperature studies

The constant-stress method recently described by Dahlquist et al. is well-suited for the study of the time and temperature dependence of viscoelastic properties. Creep data are given for polyisobutylene and GR-S rubber in the time range of 0.01 to 10 min. and the temperature range of 40 to −50°C. The data were transferred into master curves of log reduced modulus vs. log reduced time. The polyisobutylene data superposed satisfactorily using either ( a) a time reduction method based on a constant apparent activation energy for elastic deformation, or ( b) a time reduction method based on steady-flow viscosities. The two master curves coincide except in the short time range. In contrast to polyisobutylene, GR-S showed a considerable variation in activation energy with modulus. Three master curves are presented, the first calculated on the basis of a constant average activation energy, the second obtained by shifting individual modulus curves along the log time axis, and the third derived by assuming a linear dependence of activation energy on modulus. The scattering of the data decreases in order from the first to the third. The first and second curves coincide completely within experimental error. The third curve coincides with the first and second in the time range of 10 −2 to 10 1.5 min. but diverges considerably at time intervals less than 10 −2 min. As yet the concept of a modulus-dependent activation energy must be considered of doubtful theoretical significance.